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Ver^o 




HARVARD UNIVERSITY 



LIBRARY OF THE 



Department of Mining 
and Metallurgy 



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[Frontispiece^ Vol. xxxiii."] 




MAURICE DEACON. 



PRESIDENT OF THE INSTITUTION OF MINING ENGINEERS. 1906-1907. 



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TRANSACTIONS 



OF 



THE INSTITUTION 



OF 



MINING ENGINEERS. 



VOL. XXXIIL-1906-190T. 



Edited by M. WALTON BROWN, Secretary. 



Newcastle-upon-Tyne : Published by the Institution. 



Printed by Andbew Rbid & Co., Limited, Newcastle-ufonTyne. 

1908. 

\_AU rights of publication or translation are reserveA.] 



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Vex^o 



JUN151909 



ADVERTIZEMENT. 



The Institution, as %■ body, is not responsible for the statements and opinions 
advanced in the papers which may be read or in the discossions whioh may take 
place at the meetings of the Institution or of the Federated Institutes. 



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CONTENTS OF VOL. XXXIII. 



GENERAL MEETIKOS. 



PAOK. 

Adtbrtizement ii 

Contents iii 

Offigebs X 

Bte-laws xii 

Subjects for Papers xviii 



The Institution of Mining BNanrBBBS. 

1907. PAo«. 

Jane 13.— General Meeting (London) 329 

Prizes 329 

"Presidential Address." By M. Deacon 330 

Discussion 345 

« Improvements required in Inland Navigation." By Henry 

Bodolph de Salis 347 

Discossion 363 

"A Bye-produot Coking-plant at Clay Cross." By W. B. M. 

Jackson 386 

'' Notes on Bye-prodaot Coke-ovens, with Special Reference to 

the Koppers Oven." By A. Victor Koohs 398 

Discussion 416 

''The Application of Duplicate Fans to Mines." By the Rev. 

G. M. Capell 431 

Discussion 433 

Discussion of Mr. Sam Mavor's paper on ''Practical Problems of 

Machine-mining" 445 

*< Gypsum in Sussex." By W. J. Kemp and G. Alfred Lewis ... 449 

Discussion 468 

<* Water-supplies by Means of Artesian Bored Tube- wells." By 

Herbert F. Broadhurst 473 

Discussion 497 

June 14. — General Meeting (London) 501 

Discussion of Mr. A. Thompson's paper on ** Electrically-driven 
Air-compressors combined with the working of Ingersoll- 

Sergeant Heading-machines," etc 601 

" The Thick Coal of Warwickshire." By J. T. Browne 502 

Discussion 513 

'* New Rand Gold-field, Orange River Colony. " By A. R. Sawyer 530 

Discussion 531 

*' The Ozokerite (Mineral-wax) Mine of the Galizische Kreditbank, 

at Boryslaw, Galicia, Austria." By D. M. Chambers ... 535 
<< Notes on the Structural Geology of South Africa." By C. 

Sandberg 540 

Discussion 556 

" A Single-room System of Mining : An Adaptation of the Long- 
wall Method to Work in Thick Seams." By H. S. Gay ... 558 



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IV CONTENTS. 

The Institution of Mining Enginbers.— Con^nwcrf. 

1907. PAOB. 

June 14. — General Meeting (London). — Continued. 

"Cast-iron Tubbing: What is its Rational Formula?" By 

H. W. G. Halbaum 667 

Discussion 617 

Visits to Works, etc : — 

Park Royal Power-station of the Great Western Railway 

Company 634 

The Knight, Bevan k Sturge Works of the Associated Port- 
land Cement Manufacturers (1900), Limited, Xorthfleet, 

Kent 642 

" Electric Transmission of Power at the Works and Collieries of 

the Grand-Homu, Belgium." By E. Troussart 647 

** Hauling Arrangement at the Face " 663 

Florence Coal and Iron Company, Limited 664 

Discussion of Mr. H. W. G. Halbaum's paper on <' Cast-iron 

Tubbing : What is its Rational Formula ? " 664 

* ' Memoir of Sir Lowthian Bell, Bart. " 665 



Manchester Geologioal and Mininc Society. 
1907. 

Feb. 12.— General Meeting (Manchester) 170 

Discussion of Mr. Otto Simonis' paper on ** Liquid Air and its 

Use in Rescue-apparatus " 170 

"Cage-lowering Tables at New Moss Colliery." By T. H. 

Wordsworth 174 

Discussion 177 

March 12.— General Meeting (Manchester) 277 

Discussion of Mr. W. E. Garforth's paper on " A New Apparatus 

for Rescue- work in Mines " 277 

April 9. — General Meeting (Manchester) 282 

"The Cook Calorimetric Bomb." By W. H. Coleman 283 

Discussion 288 

May 14.— General Meeting (Manchester) 290 

"The Rock-salt Deposits at Preesall, Fleetwood, and the 

Mining Operations Therein." By Fredk. J. Thompson ... 291 

Discussion 298 



The Midland Counties Institution of Engineers and the Midland Institute 
OF Mining, Civil and Mechanical Engineers. 
1907. 

March 9.— Joint General Meeting (Chesterfield) 120 

Discussion of Mr. I. Hodges' paper on "An Account of Sinking 
and Tubbing at Me thley Junction Colliery, with a Description 
of a Cast-iron Dam to resist an Outburst of Water " ... 120 

Discussion of Messrs. W. N. Atkinson and A. M. Henshaw's 

paper on " The Courri6res Explosion " 124 

"Elliott Washer and Hardy Dust-extractor and Grinder." Hy 

£. Greaves 138 

Discussion 149 



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CONTENTS. y 

Thb Midland Countiss Ikstitution or Enginsibs and the Midland Institute 
OF Mining, Civil and Mechanical Enoineebs.— Con/trau^cf. 

1907. PAOB. 

March 9. — Joint General Meeting (Chesterfield). — Continued, 

Diflcnaaion of Mr. W. C. Mountain's paper on the *' Commercial 
PosBibiiities of Electric Winding for Main Shafts and 
Auxiliary Work" 160 

Midland Institvte of Mining, Civil and Mschanicai^ Engineers. 
1907. 

Feb. 20.— General Meeting (Bamsley) 89 

'* The Importance of Scientific Mining in the Barnsley District." 

ByRSutcliffe 90 

Discussion 99 

** The Most Suitable Form of Guides for Cages for Winding from 

Deep Shafte: 1,500 FeetandDeeper." By N. W. Routledge 104 
" The Most Suitable Form of Guides for Cages for Winding from 

Deep Shafts : 1,500 Feet and Deeper." By A. J. Kennedy 108 

Discussion 113 

March 23.— Excursion Meeting (AltofU) 205 

Experimental Gallery at Altofts Collieries 205 

April 9. —General Meeting (Sheffield) 208 

*' Report on Rescue-work done by Men wearing Rescue-apparatus 
in the Experimental Gallery at Messrs. Pope and Pearson's 

Collieries, Altofts, on March 23rd, 1907 *' 209 

' * The Use and Care of Gxygen-breathing Apparatus. " By M. H. 

Habershon 212 

Discussion 222 



The Mining Instititte of Scotland. 
1907. 

Feb. 13.— General Meeting (Glasgow) 52 

Discussion of Mr. G^rge Ness' paper on <* Effects of Accelera- 
tion on Winding.torques, and Test of Tarbraz Electrical 

Winding.plant" 52 

Discussion of Mr. John B. Thomson's paper on ** Tests of a Mine- 
fan" 58 

"Heading by Longwall Machines." By Sam Mavor 65 

April 11.— Annual General Meeting (Hamilton) 151 

Annual Report of the Council, 1906-1907 151 

Election of Officers, 1907-1908 153 

Accounts 154 

Discussion of Mr. John B. Thomson's paper on " Tests of a Mine- 
fan" 155 

Discussion of Mr. Sam Mavor's paper on ** Heading by Longwall 

Machines" > ... 157 

<* A Stretcher for Use in Mines." By John F. K. Brown ... 102 

« The Hanley Cage Guardian." By Albert Hanley 164 

June 29. — Excursion Meeting (Polmaise Collieries) 235 

June 29. — General Meeting (Stirling) 236 

*' Polmaise Collieries." By James Salmond 237 



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\ 

Vi COKTEKTS. 

The North of England Insttitutb of Mining and Mechanical Enoinbkbs. 

1907. PAOE. 

Feb. 9.— General Meeting (Newcastle-apon.Tync) 1 

Discussion of Mr. Otto Simonis' paper on ** Liquid Air and its Use 

in Rescue-apparatus " 2 

** Ferro-oonorete and its Applications.'* By T. J. Gueritte ... 10 

April 13.— General Meeting (Newcastle-upon-Tyne) 179 

Discussion of Mr. W« E. Garforth's paper on '* A New Apparatus 

for Rescue- work in Mines " 180 

Discussion on the Explosion at Wingate Grange Colliery ... 183 

Discussion of Mr. E. Seymour Wood's paper on *' Sinking through 
Magnesian Limestone and Yellow Sand by the Freezing-process 
at Dawdon Colliery, near Seaham Harbour, County Durham " 197 

• * Sliding-trough Conveyors. " By M. Malplat 198 

Discussion 200 

< < Memoir of the late John Daglish. " By M. Walton Brown ... 201 

June 8. — General Meeting (Newcastle-upon-Tyne) 249 

Discussion of Mr. R. Cremer's paper on *' The Pnenmatogen : 
The Self -generating Rescue-apparatus, compared with Other 

Types" ... 260 

Discussion of Mr. E. S. Wood's paper on ** Sinking through Mag- 
nesian Limestone and Yellow Sand by the Freezing-process 
at Dawdon Colliery, near Seaham Harbour, C!)ounty Durham " 251 
'* Treatment of Dust in Mines, Aboveground and Belowgrotmd." 

By Richard Harle 264 

Discussion 257 

June 6.— Excursion Meeting (Sunderland) 276 

C Pit, Monkwearmouth 275 



The Nobth Staffobdshibb Institute of Mining and Mechanical Enginbbbs. 
1907. 

Feb. 4. —General Meeting (Stoke-upon-Tren t) 76 

Death of Mr. W. H. Davies 76 

Prizes 77 

** A Gob-fire in a Shropshire Mine." By St. V. Champion Jones 78 

Discussion 84 

April 8.— General Meeting (Stoke-upon-Trent) 303 

Discussion of Messrs. W. N. Atkinson and A. M. Henshaw's 

paper on " The Courri^res Explosion " 303 

June 3. --General Meeting (Stoke-upon-Trent) 312 

"Outbursts of Coal and Gas in the Cockshead Seam, Shelton 

CoUiery." By F. K Buckley 313 

Discussion 320 

Discussion of Messrs. W. N. Atkinson and A. M. Henshaw's paper 

on " The Courri^res Explosion " 326 

June 24.->Excursion Meeting (Tutbury) ... 328 

Tutbury Gypsum-mines and Plaster-mills 328 



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COFTENTS. VII 
Ths South Statfobdshibb and Warwickshire Institute of Mining Enoinbbbs. 

1907. PAGE. 

Feb. 12. — General Meeting (Birmingham) 25 

"The Hidden Goal-fields of the Midlands." By Charles 

Lapworth 26 

Discussion 50 

April 16. — General Meeting (Birmingham) 167 

IMscnssion of Mr. F. C. Swallow's paper on " Boilers for Colliery 

Purposes*' 167 

Discnssion of Mr. A. Hanley's paper on "The Hanley Cage 

Guardian" 168 

June 4. — General Meeting (Birmingham ) 261 

Discnssion of Prof. C. Lapworth's paper on '*The Hidden Coal- 
fields of the Midlands " 261 



APPENDICES. 

I. — Notes of Papers on the Working of Mines, Metallurgy, etc., from 
the Transactions of Colonial and Foreign Societies and Colonial 

and Foreign Publications 673 

« Brown-coal Deposits of Upper Lausitz, Silesia." By Kurt 

Priemel 673 

*• Posidonia Becheri in Upper Silesian Coal-measures." By R. 

Michael 675 

" Asphalt^deposit at Mettenheim, Hesse." By A. Steuer ... 675 
< * Kaolin-deposiU of Halle-an-der-Saale, Saxony." By Ewald Wiist 676 
" Nickeliferous Magnetic Pyrites of the Black Forest, Baden." 

By E. Weinschenk 677 

** Stanniferous Deposits of the Fichtelgebirge, Bavaria." By 

Albert Schmidt 679 

*' Holzappel Metalliferoua Belt, Hesse-Nassau." By G. Einecke 680 
"Pyrites-deposits of the Western Erzgebirge, Saxony." By 

Otto Mann 680 

" Tungsten-ore DeposiU in Saxony." By R. Beck 682 

"Graphite-deposits in the Piedmontese Alps." By Vittorio 

Novarese 683 

" Aznrite-deposit of the Castello di Bonvei, Sardinia." By 

F. MUlosevich 685 

" Tungsten-ores in the Cagliari District, Sardinia." By 

Domenico Loyisato 686 

" MeUlliferous Deposits of North-eastern Sicily." By B. Lotii 687 

" Blende- and Galena-deposits of Traag, Norway." By J. H. L. 

Vogt 689 

" Gellivaara and Kiirunavaara Iron-ores, Northern Sweden " : — 

(1) By O. Stutzer 690 

(2) By O. Stutzer 692 

(3) By 0. Stutwsr 692 

"Graphite-deposits in Lapland." By O. Stutzer 693 



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VIU COXTENTS. 

APVESDICES,— Continued. 

I. — Notes of Papers, etc.— Continued* paos. 

** Auriferous Deposits of Finnish Lapland." By Curt Firoks ... 693 
**Manganiferous and Other Ore-deposits of Kizhne-Tagilsk, 
Russia " :— 

(1) ByN. Yakoviev 696 

(2) By A. KrasnopoUky 696 

*' Auriferous Deposits of Servia." By Douohan Jovanovitch ... 696 

** Mercury Ore-deposiU of Avala Hill, Servia." By H. Fischer 697 
** Ore-deposits of the Province of Almeria, Spain " :— 

(1) By O. Piitz 699 

(2) By Baron F. Fircks 701 

(3) By Baron F. Fircks 702 

**HuclvaPyrites-deposiU, Spain." By Bruno Wctzig 704 

* < Argentiferous Galena of Cadlimo, Switzerland. " By £. Mariani 707 
*' Mineral-resources of Asia Minor " :— 

(1) By Fr. Freise 708 

(2) By C. Schmeisser 709 

*< Coal-bearing Beds of Fushun, Southern Manchuria." By J. 

PaUbin 712 

** Mineral Resources of Korea." By — Berteaux 712 

*< Coal-bearing Beds in the Kuznetsk District, Siberia." By 

B. K. PoUenov 713 

" Gold-bearing Regions of Siberia " :— 

(1) By E. Ahnert 714 

(2) By A. Gerasimoff and P. I. Preobrazhensky ... 714 

(3) By E. Ahnert, M. M. Ivanoff, A. Khlaponin, P. 
Rippas and P. Yavorovsky 714 

(4) By A. Khlaponin 714 

(6) By Ernst Maier 716 

*' Mineral Resources of the Chukchen Peninsula, Eastern Siberia." 

By J. Korsuchin 719 

" Copper, Tin and Gold in Katanga, Congo Free SUte " :— 

(1) ByH. Buttgenbach 721 

(2) By H. Buttgenbach 722 

(3) By H. Buttgenbach 723 



II. — Barometer, Thermometer, etc.. Readings for the Year 1906. By 

Percy Strzelecki 726 



Index 736 



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CONTENTS. 



IX 



List of Plates :— 









PAOS. 




PAOS. 


Portrait of Mr. Mattrics 




xn 


... 396 


Dbaoon 


Frontispiece 


xm., XIV., XV., XVI. 


416 


I. 


.. 


84 


XVll 


432 


n 


. 


106 


XVIII 


... 496 


m 






112 


XIX 


612 


IV 






162 


XX 


530 


V 






166 


XXI 


... ^556 


VI. 






176 


XXII 


666 


VII 






201 


xxm 


616 


vra 






206 


XXIV.,XXV 


642 


IX 






256 


XXVL, XXVII. 


662 


X 






29S 


XXVIII 


734 


XI 






320 


XXIX 


. ... 734 



Airr Publication of a Fbdxrated Ikstttute mat be Placed at the End 
OF the Volume, ».e., "Annual Report," "List of Members," etc. 



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LIST OF OFFICERS. 



THE INSTITUTION OF MINING ENGINEERS. 



OFFICERS, 1906-1907. 



pa0t«pre0tDentd (ex-qficioj. 

Mr. William Nicholas Atkinson, H.M. Inapector of Mines, Bridgend. 

Mr. James Cope Cadman, The Clonghs, Newcastle, Staffordshire. 

Mr. James Stbdman Dixon, Fairleigh, Bothwell, Glasgow. 

Sir Lebs Knowlbs, Bart., Westwood, Pendlebury, Manchester. 

Sir William Thomas Lewis, Bart., Mardy, Aberdare. 

Mr. John Alfbbd Longden, Stanton-by-Dale, Nottingham. 

Mr. Georoe Arthur Mitchell, 5, West Regent Street, Glasgow. 

Mr. Henry Copson Pbakb, Walsall Wood Colliery, Walsall. 

Mr. Arthur Sopwith, Cannock Chase Collieries, Walsall. 

Sir Lindsay Wood, Bart., The Hermitage, Chester-le-Street. 

ptesiDent 

Mr. MAURICE DEACON, Brookfield Manor, Hathersage, Sheffield. 

Mr. Thomas Douglas, The Garth, Darlington. 

Mr. Jambs Tennant Forgib, Mosspark, Bothwell, Glasgow. 

Mr. William Birkenhead Mather Jackson, Ringwood, Chesterfield. 

Mr! Robert McLaren, H.M. Inspector of Mines, Craigmore, 77, Colinton 

Road, Edinburgh. 
Mr John Herman Mbrivalb, Togston Hall, Acklington, S.O., Northumberland. 
Mr. Thomas Wilirbd Howe Mitchell, Mining Offices, 26, Regent Street, 

Bamsley. 
Mr Robert Thomas Moore, 142, St. Vincent Street, Glasgow. 
Mr! John Newton, Woodlands, Wolstanton, Stoke-upon-Trent. 
Mr William Garside Phillips, Ansley Hall Colliery, Atherstone. 
Mr* Charles Pilkinoton, The Headlands, Prestwich, Manchester. 
Mr' John Bell Simpson, Bradley Hall, Wylam, S.O., Northumberland. 
Mr John George Weeks, Bedlington, S.O., Northumberland. 
Mr. Robert Summebsidb Williamson, Cannock Wood House, Hednesford, 

S.O., Staffordshire. 
Mr. John Robert Robinson Wilson, H.M. Inspector of Mines, West Hill, 

Chapeltown Road, Leeds. „ ^v r, »x ^ 

Mr. Wiluam Outterson Wood, South Hetton, S.O., County Durham. 

Counctllors. 

* Deceased. 

Mr. Frederick Robert Atkinson, Duffield, Derby. 
Mr. Richard Donald Bain, H.M. Inspector of Mmes. Durham. 
Mr. Harry Drummond Dawson Barblan, 21, University Gardens, Glasgow. 
Mr! Jambs Barrowman, Staneacre, Hamilton. 
Mr. George Jonathan Binns, Duffield House, Duffield, Derby. 
Mr. Archibald Blyth, Lochside, Hamilton. i^r v * 

Mr. Henry Bramall, Pendlebury Collieries, Pendlebury, Magichester. 
Mr. Bennett Hooper Brough, 28, Victoria Btreet, London, S. W. 
♦Mr Mabtin Walton Brown, 10, Lambton Road, Newcastle-upon-Tyne. 



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LIST OF OFFICERS. XI 

Mr. Charlsb Sp£abman Caknbs, Marsden Hall, South Shields. 

Mr. W11.LIAM CocHKAN Gabb, Benwell Colliery, Newcastle-upon-Tyne. 

Mr. William HxyRT Chambebs, Conisborough, Rotherham. 

Mr. William Frbdebigk Clark, The Poplars, Aldridge, Walsall. 

Mr. Gbobob Elmslky Coks, 65, Station Street, Nottingham. 

Mr. Frank Covlbon, Shamrock Hooae, Durham. 

Mr. RoBSBT Wilson Dron, 55, West Regent Street, Glasgow. 

Mr. Thomas Emerson Forster, 3, Eldon Square, Newcastle-upon-Tyne. 

Mr. JooN William Frtar, Eastwood Collieries, near Nottingham. 

Mr. William Edward Garforth, Snydale Hall, Pontefract. 

Mr. John Gsrrard, H. M. Inspector of Mines, Worsley, Manchester. 

Mr. George Clemsntson Greenwbll, Poynton, Stockport. 

Mr. Reginald Gitthrie, Neville Hall, Newcastle-upon-Tyne. 

Mr. James Hamilton, 208, St. Vincent Street, Glasgow. 

Mr. Arthitr Hasbam, Kinff Street, Newcastle, Staffordshire. 

Mr. Henrt Richardson 'Sewitt, H.M. Inspector of Mines, Breedon Hill Road, 

Derby. 
Mr. Isaac Hodoss, Whitwood Collieries, Normanton. 
Mr. George Henrt Holungworth, 37, Cross Street, Manchester. 
Mr. George P. Hyslop, The Shelton Iron, Steel and Coal Company, Limited, 

Stoke-upon-Trent. 
Mr. Douglas Jackson, Coltness Iron Works, Newmains, S.O., Lanarkshire. 
Mr. Thomas Edgar Jobling, Bebside, S.O., Northumberland. 
Mr. Austin Kirkup, Manor House, Penshaw, Fence Houses. 
Mr. Philip Kirkup, Lea field House, Birtley, S.O., County Durham. 
Mr. Charles Cattsrall Leach, Seghill Colliery, Seghill, Dudley, S.O., North- 

umberland. 
Mr. George Alfred Lewis, Albert Sreet, Derby. 
Mr. Henrt Louis, 4, Osborne Terrace, Newcastle-upon-Tyne. 
Mr. William McCrrath, 208, St. Vincent Street, Glasgow. 
Mr John Morison, Cramlington House, Northumberland. 
Mr. William Charles Mountain, The Hermitage, Gateshead-upon-Tyne. 
Mr. David Marr Mowat, Summerlee L:on Works, Coatbridge. 
Mr. Horace Broughton Nash, 23, Victoria Road, Bamsley. 
Mr. John NByiN, Littlemoor House, Mirfield, S.O., Yorkshire. 
Mr. Lucius Trant O'Shsa, University of Sheffield, St. George's Square, 

Sheffield. 
Mr. Henrt Palmer, Medomsley, S.O., County Durham. 
Mr. Matthew William Parrington, Wearmouth Colliery, Sunderland. 
Mr. William Saint, H.M. Inspector of Mines, Cromer Hou^e, Cathedral Road, 

Cardiff. 
Mr. Frank Robert Simpson, Hedgefield House, Blaydon-upon-Tyne, S.O., 

County Durham. 
Mr. John Simpson, Heworth Colliery, Felling, S.O., County Durham. 
Mr. Alexander Smith, 3, Newhall Street, Birmingham. 
Mr. Sydney Arthur Smith, 1, Princess Street, Albert Square, Manchester. 
Mr. Thomas Thomson, Fairview, Hamilton. 
Mr. John Thomas Todd, Blackwell Collieries, Alfreton. 
Mr. Thomas Turner, Caledonia Works, Kilmarnock. 
Mr. George Blake Walker, Whamcliffe Silkstone Colliery, Bamsley. 

2luDitor0, 
Messrs. John G. Benson and Son, Newcastle-upon-Tyne. 

Messrs. Lamston and Company, The Bank, Newcastle-upon-Tyne. 

Sectctati^. 

*Mr. Martin Walton Brown, Neville Hall, Newcastle-upon-Tyne. 



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XU BTE-LAWS. 



THE INSTITUTION OF MINING ENGINEERS. 



Founded July 1st, 1889. 

BYE-LAWS. 
At revised at Council Meeting held on September ISlh, 1906, 

I. — Constitution. 

1. — ^The Institution of Mining Enf^eers shall consist of all or any of the 
societies interested in the advancement of mining, metallnrgy. engineering and 
their allied industries, who shall from time to time join together and adhere to 
the bye-laws. 

2. — ^The Institution shall have for its objects — 

(a) The advancement and encouragement of the sciences of mining, metal- 



lurgy, engineering, and their allied industries. 
(h) The mtercha 



hange of opinions, by the reading of communications from 
members and others, and by diocussions at general meetings, upon im- 
provements in mining, metallurgy, engineering, and their allied 
industries. 

(c) The publication of original communications, discuasioDs, and other 

papers connected with tne objects of the Institution. 

(d) The purchase and disposal of real and personal property for such objects. 

(e) The performance of all things connected with or leading to the purpose 

of such objects. 

3. — The offices of the Institution shall be in Newcastle-upon-Tyne, or such 
other place as shall be from time to time determined by resolution of the 
Council. 

4. — The year of the Institution shall end on July 31st in every year. 

6. — ^The affairs and business of the Institution snail be managed and con- 
trolled by the Council. 

n. — ^Membbbshif. 

6. — ^The original adherents or founders are as follows: — 

(a) Chesterneld and Midland Counties Institution of Ennneers, Chesterfield. 

(bj Midland Institute of Mining, Civil and Mechanical Engineers, Bamsley. 

(c) North of England Institute of Mining and Mechanical Engineers^ New- 

castle-upon-Tyne. 

(d) South Staffordshire and East Worcestershire Institute of Mining 
En^neers, Birmingham. 

7. — ^Written applications from societies to enter the Institution shall be 
made to the Council, by the President of the applying society, who shall furnish 
any information that may be desired by the Cfouncfl. 

8. — A. — ^If desired by the Council, any of the Federated Institutes shall 
revise their bye-laws, in order that their members shall consist of Ordinary 
Members, Associate Members, and Honorary Members, with Associates and 
Students, and section B following shall be a model bye-law to be adopted by 
any society when so desired by the Council. 

B. — " The members shall consist of Ordinary Members, Associate Members 
and Honorary Members, with Associates and Students: — 



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BYE-LAWS. Xlll 

(a) Each Ordinary Member shall be more than twenty-three years of age, 
have been regularly educated as a mining, metallurgical, or mechanical 
engineer, or in some other branch of eni^neerine, according to the 
usual routine of pupilage, and have had auosequent employment for at 
least two years in some responsible situation as an engineer; or if he 
has not undergone the usual routine of pupilage, he must have been 
employed or have practised as an en^neer for at least five years. 

(h) Each Associate Member shall be a person connected with or interested 
in mining, metallurgy, or engineering, and not practisinff* as a mining, 
metallurgical, or mechanical engineer, or some other branch of en- 



gineering, 
(c) Eacl " 



(c) ^ch Honorary Member shall be a person who has distinguished himself 
by his literary or scientific attainments, or who may nave made im- 

portant communications to any of the Federated Institutes. 

(d) Associates shall be persona acting as under-viewers, under-managers, or 

in other subordinate positions in mines or metallurgical works, or em- 
ployed in analogous positions in other branches of engineerinfi". 

(e) Students shall be persons who are qualifying themselves for tne profes- 

sion of mining, metallurgical, or mechanical en^neering, or other 

branch of engineering, and such persons may continue Students until 

they attain the age of twenty-five years." 

9. — The Ordinary Members, Associate Members and Honorary Members, 

Associates and Students shall have notice of, and the privileee of attending, 

the ordinary and annual general meetings, and shall receive all publications of 

the Institution. They may also have access to, and take part in, the general 

meetings of any of the Federated Institutes. 

10. — The members of any Federated Institute, whose payments to the 
Institution are in arrear, shall not receive the publications and other privileges 
of the Institution. 

11. — After explanations have been asked by the President from any 
Federated Institute, whose payments are in arrear, and have not been paid 
within one month after written application by the Secretary, the Council may 
decide upon its suspension or expulsion from the Institution; but such sus- 
pension or expulsion shall only be decided at a meetin^jf attended bv at least 
two-thirds of the members of the Council by a majority of three-fourths of 
the members present. 

m. — SXTBSCBIPTIONS. 

12. — Each of the Federated Institutes shall pay fifteen shillings per annum 
for each Ordinary Member, Associate Member, Honorary Member, Associate 
and Student, or such other sum, and in such instalment or instalments as may 
be determined from time to time by resolution or resolutions of the Council. 
Persons joining any of the Federated Institutes during the financial year of 
the Institution shall be entitled to all publications issued for that year, after 
his election is notified to the Secretary, and the instalment or instalments due 
on his behalf have been paid. 

lY. — ^Election or Otticibbs and Council. 

13. — The officers of the Institution, other than the Secretary and Treasurer, 
shall consist of Councillors elected annually prior to August m each year, by 
and out of the Ordinary Members and Associate Members of each Federated 
Institute, in the proportion of one Councillor per forty Ordinary Members or 
Associate Members thereof; of Yice-Presidents elected by and from the Council 
at their first meeting in each year on behalf of each Institute, in the proportion 
of one Vice-President per two hundred Ordinary Members or Associate Members 
thereof; and of a President elected by and from the Council at their first 
meeting in each year; who, with the Local Secretaries of each Federated In- 
stitute and the Secretary and Treasurer, shall form the Council. All Presidents 
on retiring from that office shall be ex-officio Vice-Presidents so long as they con- 
tinue Ordinary Members or Associate Members of any of the Federated 
Institutes. 

14. — ^In case of the decease, expulsion, or resignation of any officer or 
officers, the Council may, if they deem it requisite, fill up the vacant office or 
offices at their next meeting. 



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XIV BYE-LAWS. 

y. — Dmss or OmoxBs and Coxtncil. 

16. — ^The Council ehall repreeent the Institutioii and shall act in iU name, 
and shall make such calls upon the Federated Institutes as they ma^ deem 
necessary, and shall transact all business and examine accounts, authorise pay- 
ments and may invest or use the funds in such manner as ther may from time 
to time think fit, in accordance with the objects and bye-laws of the 
Institution. 

16. — ^The Council shall decide the question of the admission of an^ society, 
and may decree the suspension or expulsion of any Federated Institute for 
non-payment of subecripuons. 

l7. — The Council shall decide upon the publication of any communications. 

18. — There shall be three ordinary meetings of the Council in each year, 
on the same day as, but prior to, the ordinary or annual general meetings of 
the members. 

19. — A special meeting of the Council shall be called whenever the President 
may think nt, or upon a requisition to the Secretary signed by ten or more of 
its members, or by the President of any of the Federated Institutes. The 
business transacted at a special meeting of the Council shall be confined to 
that specified in the notice convening it. 

20. — The meetings of the Council shall be called by circular letter, issued 
to all the members at least seven days previously, accompanied by an agenda- 
paper, stating the nature of the business to be transacted. 

21. — The order in which business shall be taken at the ordinary and annual 
general meetings may be, from time to time, decided by the Council. 

22. — The Council may communicate with the Government in cases of con- 
templated or existing legislation, of a character affecting the interests of 
mining, metallurgy, engineering, or their allied industries. 

23. — The Council may appoint Committees, consisting of members of the 
Institution, for the purpose of transacting any particular business, or of in- 
vestigating any specific subject connected with tne obiects of the Institution. 

24. — A Committee shall not have power or control over the funds of the 
Institution, beyond the amount voted for its use by the Council. 

25. — Committees shall report to the Council, who shall act thereon and 
make use thereof as they may elect. 

26. — ^The President shall take the chair at all meetings of the Institution, the 
Council, and Committees at which he may be present. 

27. — In the absence of the President, it shall be the duty of the senior Vice- 
President present to preside at the meetings of the Institution. In case of 
the absence of the President and of all the Vice-Presidents, Ihe meeting may 
elect any member of Council, or in case of their absence any Ordinary 
Member or Associate Member to take the chair at the meeting. 

28. — At meetings of the Council six shall be a quorum. 

29. — Every question shall be decided at the meetings of the Council by the 
votes of the majority of the members present. In case of equal voting, the 
President, or other member presiding in his absence, shall have a casting vote. 
Upon the request of two members, the vote upon any question shall be by 
ballot. 

30. — The Secretary shall be appointed by and shall act under the direction 
and control of the Council. The duties and salary of the Secretary shall be 
fixed and varied from time to time at the will of the Council. 

31. — ^The Secretary shall summon and attend all meetings of the Council, 
and the ordinary and annual ^neral meetinss of the Institution, and shall 
record the proceedings in the minute book. He shall direct the administrative 
and scientific publications of the Institution. He shall have charge of and 
conduct all correspondence relative to the bunness and proceedings of the 
Institution, and ofall committees where necessary, and shall prepare and issue 
all circulars to the members. 

32. — One and the same person may hold the office of Secretary and Treasurer. 

33. — ^The Treasurer shall be appointed annually by the Council at their first 
meeting in each year. The income of the Institution shall be received by him, 
and shall be paid into Messrs. Lamb ton k Co.'s bank at Newcastle-upon-Tyne, 
or such other bank as may be determined from time to time by the Council. 

34. — The Treasurer shall make all payments on behalf of the Institution, by 
cheques signed by two members of Cfouncil, the Treasurer and the Secretary, 
after payments have been sanctioned by Council. 



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BTE-ZJLWS. I XV 

36. — The BurploB funds may after resolutioii of the Council, be inveeted in 
GoTefniment securities, in railway and other debenture shares suck as are 
allowed for iuTeetment hj trustees, in the purchase of land, or in tke purchase, 
erection^ alteration, or furnishing of buildings for the use of the Institution. 
All inTestmenta shall be made in the names of Trustees appointed by the 
Council. 

36. — ^The accounts of the Treasurer and the financial statement of the 
Council shall be audited and examined by a chartered accountant, appointed 
br the Council at their first meeting in each year. The accountant's charges 
snail be paid out of the funds of the Institution. 

37. — ^The minutes of the Coundrs proceedings shall at all times be open to 
the inspection of the Ordinary Members and Associate Members. 

YI. — GSNSAAL MXBTINOS. 

38. — An ordinary general meeting shall be held in February, Mav and 
September^ unless otherwise determined by the Council; and the ordinary 
general meeting in the month of September shall be the annual general meeting 
at which a report of the proceedinffs, and an abstract of the accounts of the 
previous year ending Juljr Slst, diall be oresented by the Council. The 
ordinarr general meeting in the month of may shall be held in London, at 
which the President may deliver an address. 

39. — ^Invitations may be sent by the Secretary to anv person whose presence 
at discussions shall be thought desirable bv the Council, and persons so invited 
shall be permitted to read papers and take part in the proceedings and dis- 



40. — ^Discussion mav be invited on any ^aper published by the Institution* 
at meetrngs of any of the Federated Institutes, at which tho writer of the 
paper may be invited to attend. Such discussion, however, shall in all cases 
De submitted to the writer of the paper before publication, and he may append 
a reply at the end of the discussion. 

VH. — ^Pttblications. 

41. — ^The publications of the Institution shall consist of the reports of the 
meetings of the Institution and of the meetings of the Federatea Institutes, 
and abstracts of patents and other publications relating to mining, metallurgy 
and allied indusmes. 

The reports of the meetings shall consist of addresses, papers, and the 
discussions thereon. 

The publications may include: — 

(a) I^ipers upon the working of mines, metallurgy, applied geology, 
engineering, railways and the various allied industries. 

(h) Papers on the management of industrial operations. 

(e) Abstracts of colonial and foreign papers upon similar subjects. 

ii) Abstracts of patents relating. to miniujf and metallurgy. 

(e) Notes of ques&ons of law oonceming mines, manufactures, railways, etc. 

The following shall be deemed unsuitable, and shall be refused : — 

(a) Papers containing what is in fact advertising matter. 

(d) Papers consisting largely of matter already printed in the English 
language. 

(c) Papers consisting largely of matter foreign to the objects of the In- 

stitution or Feaerated Institutes. 

(d) Papers containing matter the publication of which may be deemed 
injurious to the interests of the Institution or of any Federated 
Institute. 

(e) Papers containing matter either libellous or slanderous, or gross mis- 

statements. 

42. — ^The Secretary of the Institution shall be responsible for the editing of 
the volumes as a whole, for the editing of the reports of the meetings of the 
Institution and of the Federated Institutes, and for the miscellaneous portion. 
The Local Secretary of each Federated Institute shall prepare and edit all 
papers and discussions of such Institute, and promptly forward them to the 
Secretary, who shall submit proofs to the Local Secretary before publication. 

43. — The Council shall appoint a Publications Committee to deal with 
ques^ons concerning the publications. 



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XYl BYE-LAWS. 

44. — A paper for reading at any of the meetings of the Institution shall be 
sent to the ^retary a clear three weeks before the meetinjg in question. The 
Secretary may refer a paper back to the author for compression or alteration, or, 
in case the matter be deemed suitable, but objection oe taken to the mode of 
expression thereof, he may refer it back to the author for amendment in this 
respect. If the Author and Secretary cannot agree as to the suitability of the 
paper, the Secretary shall submit it to two members of the Publications Com- 
mittee. If both of these approve or reject it, their decision shall be final, but 
if their views differ it shall be referred to the President of the Institution, 
whose decision shall be final. 

A paper that has been submitted to and approved by the Council of a 
Federate Institute shall be sent to the Secretary of the Insitution a clear 
fortnight before the date of the meeting at which it is intended to be read, 
together with any drawings or illustrations which may be required to accom- 
pany it. If desired by the Secretary of the Federated Institute, the Secretary 
of tne Institution wiu then have the paper printed in galley-form for dis- 
tribution at the meeting. After the meeting, the paper, revised if necessary by 
the Secretary in question, shall be returned to the Secretary of the Institution 
in its final form ready for setting up in pages. If the Secretary of the Institu- 
tion, at any time, considers the paper unsuitable for appearance in the Trans- 
actioM, he shall notify the Secretary of the Federated Institute, and shall refer 
it to two members of the Institution Publications Committee, excluding the 
Secretary or member representing the Institute from which the paper proceeds. 
If, in the unanimous opinion of these members, the paper is unsuitable for 
appearance in the TranaactioM, it shall not appear in the Transactions, but if 
their views differ, it shall be referred to the President of the Institution, whose 
decision shall be final. 

45. — Any discussion taking place at any meetings of the Institution shall 
be reported by a competent reporter. The proof of each speaker's remarks in 
the discussion shall be sent out to him by the Secretary of the Institution with 
an intimation that, if not returned corrected within seven days, it will be 
considered as correct, and the Secretary shall then edit the revised discussion. 

The Federated Institutes shall make their own arrangements for reporting 
the discussions at their meetings and for the correction of the reports of the 
speakers. The Secretary of each Federated Institute shall forward a clear 
transcript of the discussion, edited by him, to the Secretary of the Institution 
for printing. Two galley proofs, together with the manuscript, shall be sent 
to tne Secretary of the Federated Institute for correction, one of which, to- 

§ ether with the manuscript, shall be returned ready for printing within seven 
ays of receipt by him, failing which, it shall be considered to be correct. 

46. — The Council majr accept communications from persons who are not 
members of the Institution, and allow them to be reaa at the ordinary or 
annual general meetings of the Institution. 

47. — ^A paper in course of publication cannot be withdrawn by the writer, 
without the permission of the Council. 

48. — The copyright of all papers accepted for publication in the Transactions 
shall become vested in the Institution, and such communications shall not be 
published for sale or otherwise without the written permission of the Council. 

49. — Thirty copies of each paper and the accompanying discussion shall be 
presented to the writer free of cost. He may also obtain additional copies upon 
payment of the cost to the Secretary, bv an application attached to his paper. 
These copies must be unaltered copies of the paper as appearing in the publica- 
tion of the Institution, and the copy shall state that it is an *' Excerpt from 
the Transactions of The Institution of Mining Engineers." 

60. — ^The Federated Institutes may receive copies of their own portion of the 
publications in respect of such of their members as do not become members of 
the Institution, and shall pay lOs. per annum in respect of every copy so 
supplied ; and similar copies for exchan^ shall be paid for at cost price. 

51. — A list of the members, with their last-known addresses, indicating the 
Federated Institute to which they belong, shall be printed annually in the 
publications of the Institution. 

52. — The publications of the Institution shall only be supplied to members, 
and no duplicate copies of any portion of the publications shall be issued to any 
member or Federated Institute unless by order of the Council. 

53. — The annual volume or volumes of the publications may be sold, in the 
complete form only, at such prices as may be determined from time to time by 



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BYE-LAWS. XVU 

the Council: — To non-members for not less than £3; and to members who 
are desirous of completing their sets of the publications, for not less than 206. 
54. — ^The Institution, as a body, is not responsible for the statements and 
opinions advanced in the papers which may be read or in the discussions which 
may take place at the meetings of the Institution or of the Federated Institutes. 

YIII. — Medals and othsb Rbwabob. 

56. — ^The Council, if they think fit in any year, may award a sum not ex- 
ceeding sixty pounds, in the form of medals or other rewards, to the author 
or authors of papers published in the Tratuactions, 

IX. — PnOPSBTT. 

56. — The capital fund shall consist of such amounts as shall from time to 
time be determined by resolution of the Council. 

57. — ^The Institution may make use of the following receipts for its 
expenses: — 

(a) The interest of its accumulated capital fund ; 

(6) The annual subscriptions; and 

(c) Beceipts of all other descriptions. 

58. — ^The Institution may form a collection of papers, books and models. 

59. — Societies or members who may have ceased their connexion with the 
Institution shall have no claim to paiticipate in any of its properties. 

60. — All donations to the Institution shall be acknowledged in the annual 
report of the Council. 

X. — Alteration of Btb-laws. 

61. — No alteration shall be made in the bye-laws of the Institution, except 
at a special meeting of the Council called for that jsurpose, and the particulars 
of every such alteration shall be announced at their previous meetine and in- 
serted in the minutes, and shall be sent to all members of Council at least 
fourteen days previous to such special meetins^, and such special meeting shall 
have power to adopt any modification of such proposed alteration of the bye- 
laws, subject to confirmation by the next ensuing Council meeting. 



VOL. XXXIII.-IfD6.U07. 



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XVUl 



SUBJECTS FOR PAPERS. 



THE INSTITUTION OF MINING ENGINEERS. 



SUBJECTS FOR PAPERS. 

The Council of The Instdtution of Mining Engineers invite original 
communications on the subjects in the following list, together with 
other questions of interest to mining and metallurgical engineers. 



Assaying. 

Boiler explosions. 

Bore-holes and prospecting. 

Boring a^inst water and gases. 

Brickmakin^ by machinery. 

Brine-pumpmg. 

Canals, inland nayigation, and the 

canalization of riyers. 
Coal-getting by machinery. 
Coal-washine machinery. 
Coke manufacture and recovery of 

bye-products. 
Colliery leases, and limited liability 

companies. 
• Compound winding-engines. 
Compressed-air as a motive-power. 
Corrosive action of mine-water on 

pumps, etc. 
Descriptions of coal-fields. 
Diamond-mining. 
Distillation of oil-shales. 
Drift and placer-mining. 
Duration of coal-fields of the world. 
Electric mining lamps. 
Electricity and its applications in 

mines. 
Electro-metallurgy of copper, etc. 
Engine-counters and speed-recorders. 
Explosions in mines. 
Explosives used in mines. 
Faults and veins. 
Fuels and fluxes. 
Gas-producers, and gaseous fuel and 

illuminants. 
Gas, oil and petroleum engines. 
Geology and mineralo^. 
Gold-recovery plant and nrocesses. 
Graphite: its mining ana treatment. 
Haulage in mines. 
Industrial assurance. 
Inspection of mines. 
Laws of mining and other concessions. 
Lead-smelting. 
Light railways. 

Lubricating value of grease and oils. 
Lubrication of trams and tubs. 
Maintenance of canals in mining dis- 
tricts. 
Manufacture of fuel-briquettes. 
Mechanical preparation of ores and 

minerals. 



Mechanical ventilation of mines, and 
efficiency of the various classes of 
ventilators. 

Metallurgy of gold, silver, iron, copper, 
lead, etc. 

Mining and uses of arsenic, asbestos, 
bauxite, mercury, etc. 

Natural gas, conveyance and uses. 

Occurrence of mineral ores, etc. 

Ore-sampling machines. 

Petroleu m-deposi ts . 

Preservation of timber. 

Prevention of over-winding. 

Pumping machinery. 

Pyrometers and their application. 

Quarries and methods of quarrying. 

Rock-drills. 

Safety-lamps. 

Salt-mining, etc. 

Screening, sorting and cleaning of 
coal. 

Shipping and discharge of coal-cargoes. 

Sinking, coffering and tubbing of 
shafts. 

Sleepers of cast-iron, steel and wood. 

Spontaneous ignition of coal and coal- 
seams. 

Stamp-milling. 

Steam-condensation arrangements. 

Steam-power plants. 

Submarine coal-mining. 

Subsidences caused by mining-opera- 
tions. 

Surface-arrangements at mines. 

Surveying. 

Tin-mining. 

Transport on roads. 

Tunnelling, methods and appliances. 

Utilization of dust and refuse coal. 

Utilization of sulphureous gases re- 
sulting from metallurgical pro- 
cesses. 

Ventilation of coal-cargoes. 

Water as a motive-power in mines. 

Water-tube boilers. 

W^atering coal-dust. 

Water-incrustations in boilers, pumps, 
etc. 

Winding arrangements at mines. 

Winning and working of mines at 
great depths. 



For selected papers, the Council may award prizes. In making 
awards, no distinction is made between commimications received from 
members of the Institution or others. 



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TRANSACTIONS 

or 

THE INSTITUTION 
MINING ENGINEEES. 



THE NORTH OF ENGLAND INSTITITTE OF MINING 
AND MECHANICAL ENGINEERS. 



GENERAL MEETING, 
Held in the Wood Memoktal Hall, Newcastle-upon-Tyne, 
February 0th, 1907. 



Mr. J. H. MERIVALE, President, in the Chair. 



The Secretary read the minutes of the last General Meeting 
and reported the proceedings of the Council at their meetings on 
January 20th and that day. 



The following gentlemen were elected, having been previ- 
ously nominated : — 

Members — 
Mr. Alexander Richard Bekenn, Mine-manager, Dundee Coal Company, 

Limited, Talana, Natal, South Africa. 
Mr. EvENCE CoppEE, Civil Engineer and Managing Director of Collieries, 

Avenue Louise, 211, Brussels, Belgium. 
Mr. Ernest Charles Dunkbrton, Mechanical Engineer, 97, Holly Avenue, 

Newcastle-upon-Tyne. 
Mr. John Thomas Foulis, Mine-owner and Mine-manager, Durban House, 

Ramsey, S.O., Isle of Man. 
l^r. Frederick James Raine, Colliery Manager, Etherley Grange Colliery, 

Bishop Auckland. 

Associate Members— 
Mr. Wilson Ormrod, Union Buildings, St. John Street, Newcastle-upon-Tyne. 
"Mr. Frederick George Waley, The Bellambi Coal Company, Limited, 
9, Bridge Street, Sydney, New South Wales, Australia. 

1 



TOL. XXXfII.-1906-U07. 



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2 DISCUSSION LIQUID AIE AND ITS USE IN RESCUE- APPARATUS. 

Associate— 
Mr. Alfred Hill Askew, Under-manager, 16, Telford Street, Gateshead- 
upon-TjTie. 

Students— 
Mr. William Grace Grace, Mining Student, Hall Garth Hall, Winlaton,. 

Blaydon-upon-Tyne, S.O., County Durham. 
Mr. Herbert Stanley Hunter, Mining Student, Blakelaw, Kenton, New- 

caatle-upon-Tyne. 



DISCUSSION OF MR. OTTO SIMONIS' PAPER ON 
"LIQUID AIR AND ITS USE IN RESCUE- 
APPARATUS.'** 

Mr. Henry Simonis (London) exhibited the aerolith appar- 
atus, and also made some interesting experiments. Liquid air was 
preferably stored in vessels designed by Sir James Dewar : these 
were practically vacuum vessels, but closed by a thick felt-cover 
through which it wads possible for the air to penetrate to a small 
extent. In such a bottle, liquid air would keep for aboift 12 days : 
the evaporation not exceeding 6 per cent, per day. It was easy 
to transport, and if packed in a case could be forwarded ordin- 
arily by railwaj^ as there was no danger whatever of its explod- 
ing. A vessel containing 3^ pints enabled the wearer of the 
aerolith apparatus to work for 60 to 70 minutes, and a large 
vessel holding 9 pints was sufficient for 3 hours' work. Liquid 
air was approximately of the same specific gravity as water, 
weighing about 62^ pounds per cubic foot and 10 pounds per 
gallon, and therefore when filled with 9 pints for 3 hours' work, 
the apparatus (which weighed 14 pounds) would weigh 25 pounds. 
Liquid air cost about 6d. per gallon, when made with 
a small plant; and with a larger plant the cost would be con^ 
siderably reduced. By the Claude system, it was calculated that 
one horsepower (suction-gas or any other cheap method of produc- 
ing power being used) would produce 4 gallons of liquid air at a 
cost of l^d. per gallon. 

Mr. A. L. Steavenson (Durham) said that no one had a 
greater admiration than himself for the skill and knowledge 
which had been employed to perfect life-saving apparatus during 
the last 50 years ; and yet, at the present day, Mr. G. A. Meyer 
stated that " it was difficult to understand why the Schwann 
apparatus had, for so many years, been entirely forgotten."! The 
* Trans, hist. M. E, , 1906, vol. xxxii. , page f Ihid,^ vol. xxxi. , page 579^ 



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DISCUSSION — LIQUID AIR AND ITS USE IN RESCUE- APPARATUS . S 

Fleuss apparatus, and many others, one after another, had all 
come and gone, because they were found to be of no practical 
use. At a time when apparatus of this kind was called into 
requisition, it was necessary for the wearer to scramble over 
difficult falls and sometimes to squeeze through very small pas- 
sages, then a man found that his ordinary pit-clothes were an 
encumbrance ; and it was as much as he could do to trail him- 
self through, without having an apparatus to carry on his 
back. In 1854, Mr. T. T. Hall, a good practical pitman, brought 
the subject of rescue-work before the members, and recommended 
the use of pipes carried along the main roads; and he (Mr. 
Steavenson) told them to-day that this was the best suggestion 
that had been made during those 63 years.* In many mines 
compressed air was being used, and he (Mr. Steavenson) suggested 
that the pipes should be carried along the main roads and fitted 
with cocks, so as to give off the air necessary to help any persons 
shut off. In most cases the members were told that 2 or 3 hours 
was the utmost limit of time for working a modern rescue- 
appliance, but Mr. A. M. Henshaw, a thoroughly practical man, 
had stated that in 37 minutes confusion of mind occurred in the 
case of a man, who was 200 feet away from everybody 
el8e;t he began to lose confidence and would throw off the 
apparatus, and it was owing to this cause that a man, wearing 
a rescue-apparatus, was killed at the Courrieres mines.{ The 
rescuers in that disaster did not save any lives, but they lost 
one, because the wearer of the apparatus had lost confidence in 
it. Dr. J. S. Haldane and Mr. Bennett H. Brough approved 
of the use of rescue-apparatus ; § but they were not practical 
pitmen, and did not know what it was to travel a fallen road 
filled with irrespirable air. Mr. W. E. Garforth stated that 
" considering the interval [60 years] that has elapsed since the 
first efforts were made, it is disappointing to have to admit 
that there is not, at the present time, a rescue-apparatus which, 
can be fully relied upon,"|l and he (Mr. Steavenson) agreed with 
that conclusion. Mr. Garforth had erected an experimental 
gallery to test the different forms of rescue-apparatus,ir but 

♦ Trarvt. ^\ E, Inst,, 1854, vol. iL, page 87. 

t Trans. Inst, M, E,, 1906, vol. xxzi., page 615. % Ibid-f vol. xzxL, page 610. 

§ Ibid,, voL xxxL, page 617. || Ibid., vol. xxxi., page 628. 

f *^ Experimental Gallery for Testing Life-saving Apparatus," by Mr. W. 
£. Garforth, Trans. Inst. M. E., 1901, vol. xxii., page 169. 



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4 DISCUSSION — LIQUID AIR AND ITS USE IN RESCUE-APPARATUS. 

that was not sufficient. The man who submitted to experiment 
in such a gallery knew that he could get out of it in 10 
seconds, and would not, therefore, lose his confidence in an 
appliance. Supposing, in a case like the Courrieres mines, that 
the rescue-party got in after much trouble, and that there was, 
say, a length of 1,500 feet, where there was good air, and then a 
noxious zone of 1,500 feet; after getting through that, what 
good purpose could a man wearing a rescue-apparatus fulfil ? If 
he did find a number of men he would be quite unable to bring 
them through that zone of 1,500 feet of noxious gases. The 
rescue-party could never do any good work, unless by some means 
they carried fresh air with them. At the Courrieres collieries 
nothing was accomplished beyond bringing out a number of dead 
bodies, and no good purpose was served by that. The best plan 
was to carry the fresh air in with them, and it was the only plan 
that held its own to-day. The members were much indebted to 
Messrs. W. N. and J. B. Atkinson for the time and trouble which 
they had devoted to the question of the prevention of coal-dust 
explosions. There was no reason why the roads of a mine should 
not be kept perfectly clo«n; let them provide sprinkling or 
spraying apparatus if desired, but certainly let the dust be kept 
out. As another way of preventing the devastation which takes 
place, he would advocate that the stoppings be bowed slightly 
outward, so that they could not be shifted or injured by an explo- 
sion ; and then they would have a permanent road which no 
explosion could destroy, and which would enable them to pene- 
trate into a mine whenever it became necessary to do so. 

Prof. Henry Loris (Armstrong College) asked whether the 
apparatus described by Mr. Simonis had ever been tested, so as 
to ascertain that one gallon of liquid air would actually keep a 
man supplied with fresh air for 3 hours: this was about 40 
cubic feet of air per hour, which was a somewhat small allowance, 
unless the man got some external air. Tested in the air of an 
ordinary room, which was drawn back and was available for 
breathing, this quantity of air might be satisfactory ; but, if the 
apparatus was used in an irrespirable atmosphere, it might easily 
be too small. It would be interesting, therefore, to know 
whether any practical tests had been made on this point. He 
was not at all sure that the differential evaporation, as between 



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DlSCrSSIOX — ^LIQUID AIB AND ITS USE IK RESCUE-APPARATrS. 5 

nitrogen and oxygen, which was claimed as an advantage for 
liquid air, was not rather a disadvantage, as a human being wat^ 
not constructed so that he could breathe, without discomfort, prac- 
tically pure nitrogen or oxygen. He also had his doubts as to 
any benefit that might result from the reserve air-bag, which 
would become distended with the air which had been breathed by 
the wearer, and which was (as a last resource in the event of the 
supply of liquid air running out) to be breathed again, at a 
time when the man would be fagged and worn out, and, therefore, 
in special need of fresh air. 

Mr, T. E. FoRSTEE (Xewcastle-upon-Tyne) said that he 
supported, in a great measure, Mr. Steavenson's views. Rescue- 
apparatus must be used with a great deal of care and caution. 
Where a pit had to be reopened after an explosion, the air must 
be systematically taken in by the explorers. The only use which 
he saw for the apparatus was in the case where men were over- 
come with gas in places which could be easily reached; and he 
knew of an instance, recently, where an appliance of this kind 
might have saved the lives of two men. The apparatus would 
also be useful to make explorations in advance of the air, so as 
to see the direction in which to open out most easily. 

Mr. C. C. Leach (Seghill) said that the apparatus woidd 
frequently get out of order, and a possible danger would arise, as 
nobody would know exa<itly whether it was ready for use, for 
these appliances were not used everyday. 

Dr. Thomas Oliver (Newcastle-upon-Tyne) said that the 
subject was one in regard to which he could only offer a few 
remarks of a purely academic character, as he had had no experi- 
ence whatever of the practical use of rescue-appliances such as 
were before the members to-day. Still, he was one of those who 
thought that they should not strike altogether a despondent note. 
He quite agreed with Mr. Steavenson, if they could carry air 
into the pits as far as they possibly could, that this was the 
right thing to do. Experience had already shown the value 
attached to such apparatus in the case of fire, etc., and he thought 
that the time had come — ^for the Courrieres explosion had 
awakened a spirit of public enterprise in the matter, and legisla- 
tioli had already done much for the safety of the men while 
working — when something would have to be done by science in 



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6 DISCUSSION — ^LIQUID AIR AND ITS USE IN EESCUE-APPARATUS. 

regard to the saving of life after explosions. Small quantities 
of carbon monoxide were sufficient to bring about headache and 
dizziness, followed in a short time by loss of power in the limbs, 
which prevented the miner, though most wishful to escape, from 
getting away, for he would soon fall and die. ilr. Steavenson 
had alluded to the presence of dead bodies in the pit, and he 
(Dr. Oliver) thought it was only right to say that there was 
nothing that proved such a source of discomfort and danger as 
the large number of bodies in the Courrieres mine, all of which 
were undergoing extremely rapid putrefaction. Whether bodies 
were left;, in the pit or not, was a question which would have to 
be solved by mining engineers themselves. There was certainly 
the dang'er that a rescue-apparatus might not work at the proper 
time ; but, without committing himself to an opinion on that 
matter, the time had come when they were almost obliged to face 
the question, and see whether something could not be done in 
the way of using rescue-apparatus. It was perfectly clear that 
men could not under ordinary circumstances go into parts of 
the mine where carbon monoxide was ; but if by such appliances 
as these they could go in and stay 1 hour, or longer, and if it 
could be shown that they could travel through the difficult places 
mentioned by Mr. Steavenson, a great deal would have been 
accomplished. He (Dr. Oliver) would not discourage the use of 
scientific appliances of this kind, but would rather encourage 
them, and therefore good service had been done by Mr. H. 
Simonis in coming to explain this apparatus that day. There 
was not the least doubt that, after explosions, carbon monoxide 
was the cause of the death of miners. The largest number of 
men who died in the Courrieres mine died from that cause, and 
very few from shock and burns. It was an interesting point, 
and he had found the same thing in experiments on animals, 
that many of the miners died from pneumonia after being 
rescued. In the case of animals that had not been killed by 
carbon monoxide, a few days afterwards they died from pneu- 
monia, and, on microscopical examination of the lungs he had 
found small haemorrhages in the air-cells of the lungs. If this 
rescue-work was to be encouraged, he (Dr. Oliver) thought that 
they should follow Mr. W. E. Garforth's suggestion that training 
galleries should be erected where men might be put through the 
same trials as those that they would have to undergo in the mine 
after an explosion ; and, if they could stay in the pit under these 



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DISCUSSION — ^LIQiriD AIE AKD ITS USE IN EESCUE-APPAHATUS. 7 

conditions for 2 or 3 hours, he was of the opinion that the value 
of the apparatus would be quite substantiated. 

He (Dr. Oliver) thought that other important facts would 
come out soon in regard to carbon monoxide. If they were 
going to train men for rescue-work, there was something in over- 
coming the initial nervousness alluded to; therefore, men who 
had been trained were much more likely to go into the pit, know- 
ing how far the apparatus could be relied upon. Perhaps, too, 
they could be trained to the inhalation, within limits, of carbon 
monoxide. It was a well-known fact that animals could be 
exposed to air containing carbon monoxide to the extent of caus- 
ing 25 per cent, of saturation of the colouring matter of their 
blood, that is to say, to cutting oflE one-quarter of the respiratoiy 
power, and with the remaining three-quarters they got on very 
well. With carbon monoxide there was at first a certain amount 
of blood-destruction, but the red blood-corpuscles subsequently 
became increased, and the respiratorj'^ power was quite sufficient 
to overcome the deficiency. These animals lived and had 
€;xcellent health, they improved in weight, the blood improved in 
quality; and they could, by gradually increasing the percentage 
of carbon monoxide, carry it to 35, or even 45, per cent., and the 
animals would still live, while one which had not been so trained 
would die in a very short time if placed in such conditions. 
He therefore threw out the suggestion that, if Mr. Garforth*s 
proposed galleries were erected and Messrs. Nasmith and 
Oraham's experiments* were confirmed re carbon-monoxide 
poisoning, a gradual acclimatization of men to mixtures of carbon 
monoxide might be shown to be possible within certain limits, 
as in the case of animals. 

Mr. C. C. Leach (Seghill) asked whether Dr. Oliver advocated 
that all who went down the mine should be taught to breathe 
an atmosphere containing a high percentage of carbon monoxide. 

Dr. T. Olivee said that he had only stated what had been done 

with animals : he did not venture himself to suggest that the men 

should do so, but it was worth consideration. If men could 

become acclimatized to carbon monoxide, it would prove of great 

value, especially if a certain amount of fresh air, in cylinders, 

could be carried in by the rescue-party for the entombed miners. 

• The Hoematology of Carbon- monoxide Poisoning," by Mr. G. O. Nasmith 
and Mr. D. A. L. Graham, Journal of Phyftiology, 1906, vol. xxxv., page 32. 



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8 DISCUSSION — LIQUID AIE AND ITS USE IX EESCUE-APPAEATUS. 

Mr. C. C. Leach remarked that they would probably want to- 
send in only a few men, but how were the hundreds alreadjr 
in the mine to be saved ? 

Dr. T. Oliver said that fresh air or cylinders of oxygen should 
be carried in by the rescue-parties. 

Mr. Heney Simonis, replying to the discussion, said that Mr. 
A. L. Steavenson's remarks were directed against all i-escue- 
apparatus ; but, after Dr. Oliver's remarks, he did not think that 
he need reply to him. The use of pipes was an old idea, and, only 
about a month ago, he discussed with Dr. J. S. Haldane the possi* 
bility of leading liquid air in pipes to be used in mines, and 
sprayed by sprinklers, as water was used in combatting a fire, that 
was to say, whether it would be possible, with certain appliances, 
to arrange that the liquid air should be automatically released, 
and the liquid air could then be poured into the pit so as to purify 
the air and produce a breathable atmosphere at the same time. 
He did not think that it would be possible to reduce the size and 
encumbrance of the aerolith apparatus below its present dimen- 
sions: it was certainly, by far, the lightest and most compact 
form that had yet been introduced. With regard to practical 
experience with the apparatus, a complete installation, at one of 
Baron Rothschild's collieries in Austria, had been working for 
about 3 months ; and another similar plant had been erected and 
would be completed at another colliery within a few days. It 
had been proved thereby that 3 hours' work could verj' easily be 
performed with the apparatus, even allowing a wide margin, when 
charged with 1 gallon of liquid air, the equivalent of 120 cubic 
feet of breathable air, and this was more than sufficient for anj^ 
man working for 3 hours. He (Mr. Simonis) did not put any 
stress on the reserve-bag; it was only the very last resource pos- 
sible, and experiments had shewn that the air contained in this 
bag was still holding a larger percentage of oxygen than ordinary 
atmospheric air. There was no possibility of the apparatus going 
out of order, and as there was not a single valve nor complication 
of any kind, the apparatus was bound to work the moment that 
liquid air was poured in, although it might have been lying un- 
touched for any length of time. It did not follow that pure 
oxygen would do a man any hann, because a man's lungs were so 
constructed that they could not take more than a certain amount 



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DISCUSSIOX — LIQUID AIR AND ITS USE IN RESCUE-APPARATUS. 9» 

of oxygen, so that any excess would simply flow away with the 
air exhaled, and so do no harm whatever. Dr. Oliver s remarks 
about carbon monoxide were very interesting to him personally, 
and absolutely new ; and he would try to get some men to try the 
suggested experiment. A plant capable of producing about 0*9 
gallon of liquid air per hour would cost from £300 to £400, and it 
would require from 6 to 8 horsepower, so that according to the cost 
of the power, the cost of producing liquid air could be calculated. 
Under conditions, not at all favourable, the cost would not exceed 
2s. 4d. per hour or 2s. 7d. per gallon. 

Mr. T. C. FuTERS asked whether this cost included interest- 
on the cost and depreciation of the plant. 

ifr. H. SiMoxis said that the manufacture had been sublet, 
and the cost, therefore, included everything possible — and prob- 
ably a considerable profit as well. 

The President (Mr. J. H. Merivale) thought that there was 
room, both for the carrying out of Mr. Steavenson's suggestion,, 
and for such appliances as those put forward by Mr. 0. Simonis,. 
Mr. G. A. Meyer, Mr. W, E. Garf orth, and others ; more especi- 
ally if they could be perfected or brought nearer to perfection. 
Dr. Oliver's remarks had been most interesting, and he had no 
idea that it was possible for an animal to become immune to 
carbon monoxide, and to breathe air containing that gas. Con- 
sequently, if an animal could breathe a large percentage 
of carbon monoxide, it seemed reasonable to suppose it 
possible that a man could become accustomed to breathe much 
larger proportions than at present. This was a most important 
point, and no doubt would be followed up by those gentlemen who: 
were making a study of this question. 



Mr. T. J. Gueritte's paper on " Ferro-concrete and its 
Applications " was read as follows : — 



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10 



FEREO-COXCEETE AXD ITS APPLICATIONS. 



FERRO-COXCRETE AXD ITS APPLICATIOXS. 



By T. J. GUERITTE, C.E., B.Sc., M.Ikst.C.E. (France). 



Concrete, as is well known, has a high coefficient of resistance 
to compressive strains, but its resistance to tensile or shearing 
strains is low, and it would be very uncertain to rely upon it. 
On the other hand, iron and steel have a high resistance to com- 



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■.•-.• -..v.. ..; r .>•.'.■.•-.. ••••I 


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ii 



Fio. I.—Ferro-concretk and Iron Beams. 

pressive tensile and shearing strains. It is, therefore, a natural 
thing to try to compensate the shortcomings of concrete by the 
use of steel : that is, to use concrete in a structure wherever 
there is compression; and to meet the shearing and tensile 
stresses where they occur bj- means of iron or steel. 



--- 



WB 



Fig. 2.- Shearing -stresses in a Beam. 

Such is, in a few words, the principle of ferro-concrete con- 
struction. If, therefore, a ferro-concrete beam be compared with 
a rolled joist (fig. 1), the steel rods placed in the lower parts 
represent the line of traction which, in the rolled joist, is con- 
stituted by the lower flange. The concrete which forms the floor- 
ing above the beams is relied upon to resist the compressive 
■strain, and may be considered as playing the part of the upper 



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FERRO-CONCRETE AND ITS APPLICATIONS. 



11 



flange of the rolled joist. The weh is formed by the concrete, 
which encases the bars and connects the axis of compression to 
the axis of tension. But concrete alone would not be sufiicient 
for the purpose, as it would not resist, the shearing stresses. 

The effect of shear- 
ing stresses is to provoke 
the formation of cracks 
in the beam. These 
cracks make an angle of 
nearly 45 degrees with 
t he horizontal near the 
supports ; this angle de- 
creases from the sup- 
ports to the middle of 
the span (fig. 2). In 

order to meet these stresses, stirrups made of hoop-steel (fig. 3) 
are fixed on the lower bar, and, being disposed vertically (fig. 
4), connect the axis of compression with the axis of tension 




Fig. 3.— Stirrup and Rod. 



-mTto-TTi-r-i-x4^r ■ 



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Fig. 4. Ferroconcrete Beams and Pillars. 



and oppose the formation of cracks which, without them, would be 
the result of the action of shearing stresses. In most ferro- 
concrete structures the beams are continuous, and practice shows 
that it is possible and certainly very economical 
to consider them as semi-fixed at both ends in- 
stead of supported only. But then tensile stresses 
appear at the upper part, near the supports. Steel 
will therefore be necessary there, and one of the 
best ways to provide for it is to bring diagonally 
to the upper part of the beam some of the bars 
which were at the bottom in the middle of the 
span and which are not required any more near 
the supports ; for in such a beam there is near the 
supports no tensile strain on the lower parts, as 
it is confined to the upper portion. This dis- 
position (fig. 4), and the triangle thus formed, gives groat 
rigidity to the whole structure. 




Fig. 5. — Ferro- 
concrete Pillar. 



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12 



FERRO-COXCRETE AND ITS APPLICATIONS. 



The writer's remarks about beams applies, of course, equally 
to the flooring itself which may be considered as a beam, verj' 
wide and of small depth. 




Fig. 6.- Dwelling-house, Rue Dantox, Paris. 

The pillai^s form the most important component parts of a 
ferro-concrete building. A pillar, generally speaking, is sub- 
mitted only to compressive strains, and therefore both concrete 
and steel are suitable for its formation (fig. 5). Bars varying in 



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FERRO-CONCEETE AND ITS APPLICATIONS. 



18 



number and size are embedded in a block of concrete : therefore 
both elements work together, and each of them takes part of the 
load to be supported. 

The first applications of ferro-concrete construction were, the 
writer believes, made in the shape of fireproof floors, pillars and 
walls. But these applications belong more to architecture (fig. 
♦)) than to engineering, and he will not, therefore, add anything 
to the general principles already described. 




Fio. 7. — Warehouse for Co-operative Whoijesale Society, Limited, 
Newcastle-upon-Tyne. 

There is a question which the writer thinks is of interest, 
namely, that of very bad foundations in which settlements are 
anticipated on account, for instance, of colliery- workings in the 
immediate vicinity. Here, ferro-concrete has been found to be a 
most useful and economical solution of the problem. To illus- 
trate this view, the writer will take the case of a building entirely 
built of ferro-concrete on the Quay, at Xewcastle-upon-Tyne. 
This is an eight-storey building, and each floor has to carry the 



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14 



FBRRO-COXCRETE AND ITS APPLICATIOXS. 



enormous weight of 6 cwts. per square foot (fig. 7). In addition 
to this, the flat roof is calculated for the storage of empties and 
non-perishable goods. The result is that the pillars in the base- 
ment have to carry loads amounting to 600 tons, and some of 
them have even to support nearly 900 tons. Now, the foundations 
tions being composed of slush, peat, quicksand, etc., to a depth of 
60 feet, it was evident that the foundations had to be formed 
either by piles driven to that depth or by cylinders, at a very great 
cost ; it was, therefore, decided to adopt f erro-concrete. A general 
ferro-conerete platform was built over the whole area, spreading 



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Fig. 8.— Longitudinal Section op Warehouse. Scale, 36 Feet to 1 Inch. 

the load at the rate of 28 tons per square yard. Of course, 
such a platform would have been inadequate by itself to with- 
stand the enormous strain imposed; but by means of pillars 
and walls it is connected to the remainder of the building, and 
the whole structure forms a monolithic block, a sort of huge box- 
girder, 100 feet high and with a span of 130 feet. It was assumed 
that the whole block would sink 6 inches below its original level 
and without deterioration. The sinking process was carefully 



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FEHRO-COXCRETE AND ITS APPLICATIONS. 



15 



watched, and it was found, ultimately, that the building had 
sunk as anticipated, and without ill effect on its strength (figs. & 
and 9). 

Fig. 10 shows the effects of the subsidence of made ground at 
Bizerta, Tunis, on ferro-concrete buildings. These were restored 
to a horizontal position, at a lower level, by excavations. 

The construction of water-tanks (fig. 11) and reservoirs offers 
a vast field to ferro-concrete. A list of reservoirs built on the 
Hennebique system alone, during the last seven years, numbers 




Fig. 9. — Cross-section of Wareuousb. Scale, 36 Feet to 1 Inch. 

over 1,000. This, it seems, would tend to give faith to the most 
sceptical. The flat roofs of ferro-concrete buildings are in many 
cases used as water-tanks. 

A form of reservoir, of which a word must be said, is grain 
or coal-silos, or hoppers, the latter being of special interest (figs. 
12, 13 and 14). They are calculated as a sort of reservoir, due 
allowance being made for the friction of the grain or coal on the 
walls. 

Fig. 15 shows the entrance to a large culvert, 32 feet wide, 
at Newcastle-upon-Tyne, forming a new coui*se for the Ouse- 



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16 



FEERO-CONCRETE AND ITS APPLICATIONS. 




Fig. 10.— HuiLDixGs for Manufactories, Bizerta, Tunis. 

bum. Fi^. IG shows a ferro-concrete aqueduct for conveying 
water to the water-power plant at the Simplon tunnel-works. 




Fig. 11.— Water-tank at Newton-le- Willows. 



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FESBO-CONCRETE AlID ITS APPUCATIONS. 



17 




FfrrfffET! 

'Hi 



.'-'^-i 




Fig. 12.— Coal-hoppeks at Gabmaux Collieries, France. 

Ferro-concrete bridges have very nearly the same appearance 
as metallic bridges, and are, indeed, constructed on nearly the same 
principles. They have a very small rise, varying from 4 per cent, 
to 10 per cent, of the span. The total thickness at the key is 




FlO. 13. — COAL-HOPPEBS AT LeNS COLLIERIES, FRANCE. 
TOL. XXXU 1.-1906-1907. 2 



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^8 



FERRO-COXCRETE AND ITS APPLICATIONS. 



very small. In the Liege bridge, for instance, at the middle arch, 
with a span of 184 feet, the total thickness of the key is only 1$ 
inches from the intrados of the arch to the upper part of the foot?^ 
path (fig. 17). It is evident that such a light structure offers ^. 




Fig. 14.— Coal-washino Plant at Aniche Ck)LLiEBiES, France. 

greater space for the passage of floods, and it is possible, there- 
fore, to lessen by a few feet the distance between the road-level 
and the ordinary water-level. The consequences being a lower- 



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FERHO-COXCRETE AND ITS APPLICATIONS . 



1» 



gradient, and a saving in the abutments and filling for 
the approaches of the bridge. Another point well worthy of con- 
sideration is that the weight of a ferro-concrete bridge is much 
smaller than the weight of a masonry bridge, and the foundations 
consequently are less costly. 

Some apprehension was formerly entertained as to the security 
offered by ferro-concrete bridges. However, the writer finds that 
during the last seven years more than 800 bridges have been 
built in Hennebique ferro-concrete, and most of these bridges 
have been severely tested. 




Fio. 15. — OusEBUBX Culvert, Newcastlb-upon-Tyne. 

Ferro-concrete has also been applied to river and marine 
works (fig. 18). Most of these works contain piles and sheet- 
piles of ferro-concrete. Their principle of construction is some- 
what analogous to that of pillars. They are consituted by a 
certain number of bars embedded in concrete, and maintained at 
the required distance apart by means of distance-pieces. Their 
section may vary according to the requirements from, say, 4 
inches by 8 inches for very small sheet-piles, up to 20 inches 
square. Their length when moulded in one piece has attained. 



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20 



FERRO-CONCRETE AND ITS APPLICATIONS. 



more than 65 feet. The question of weight alone prevents the 
moulding of longer piles in one piece ; but, in cases where greater 
lengths are required, there are means of connecting piles moulded 




beforehand, insuring a very rigid joint, and it is possible to drive 
ferro-concrete piles almost to any depth. 

Architects sometimes object to ferro-concrete, owing to the 
supposed plainness of its appearance. Although engineers are 



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FEEEO-CONCEETE AND ITS APPLICATIONS. 21 

not concerned so much about SBsthetics, the writer happens to 




5 









know that ferro-coDcrete lends itself to elaborate oniamentation 



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22 



FEEEO-CONCRETE AND ITS APPLICATIONS. 



in buildings (fig. 6), and as regards bridges, jetties, reservoirs, 
etc., it compares very favoui-ably with other materials. 

It is sometimes argued that ferro-concrete is too new a 
material. But ferro-concrete structures have been erected now 
for fifteen years without showing any sign of decay, and have 
been erected by thousands. Continuous vibrations, which were 
at first supposed to be very detrimental to ferro-concrete, do not 
affect it in the least. A most serious enquiry has been made on 
this particular point by order of the French Government, and the 




Fio. 18.— CoAL-SHippiNO Quay and Jetty, Southampton. 

conclusions of the report are absolutely positive. The writer need 
hardly state that the legend, that in course of time the steel bars 
become rusted in concrete and lose a great pai-t of their strength, 
has been abandoned long ago, it having been proved that oxide 
of iron cannot exist in contact with cement. Besides, every- 
day practice shows that rusted bars embedded in concrete will 
be, in the course of a month or so, as bright as when leaving the 
rolling mill, the rust having been deoxidized by the formation 
of ferrite of calcium, which forms a protective skin all round 
the bars. 



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FERRO-COXCRETE AND ITS APPLICATIONS. 



23 



The adherence of concrete to iron has also been questioned. 
But the coefficient of adhei-ence has now been determined, and 
its value is such that it justifies the practice of ferro-concrete 
specialists who i*eckon on concrete alone to make the junction 
between the different metallic parts of the structures. The writer 
means that two bars, which have to be connected, are merely set 
close to each other in the moulds and embedded in the concrete. 




Fig. 



19. —Coal- HOPPERS at Southampton with a 
Capacity of 4,000 Tons. 



As regards the expansion of concrete and steel, their 
coefficients are identical up to the fifth decimal figure, and in 
practice it may be assumed that they are equal ; consequently, in 
the fiercest fires, ferro-concrete resists without losing any of its 
qualities of strength and elasticity. 

Amongst the other advantages of ferro-concrete are its cheap- 
ness, its rapidity of execution, the solidaritj^ between all the 



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24 FERRO-COXCRETE AXD ITS APPLICATIONS. 

elements of the structure, and its durable properties which 
obviate almost entirely subsequent expense in upkeep, painting,, 
etc., its absolute immunity against the attack of wood-worm,, 
dry-rot, and damp-rot, and the like. 

The writer will close by repeating the words by which the- 
chairman of the committee of research on ferro-concrete, insti- 
tuted by the French Government, characterized ferro-concrete : — 
** Masonry has its weakness, which is insuperable, namely, the^ 
joint ; metallic structures have also an insuperable source of 
weakness, the rivet ; ferro-concrete presents no joints and does not 
rely on rivets, it is not made of pieces jointed or fitted together, 
it is a block.'* 



The President (Mr. J. H. Merivale) moved a vote of thanka 
to Mr. Gueritte for his instructive paper. 

Prof. H. Louis seconded the resolution, which was cordially 
approved. 



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TRANSACTIONS. 25- 



THE SOUTH STAFFORDSHIRE AND WARWICKSHIRE. 
INSTITUTE OF MINING ENGINEERS. 



GENERAL MEETING, 

Held at thx Univebsitt, Bournbbook, Bibminuham, 

Febbuabt ISth, 1907. 



Mb. F. a. GRAYSTON, Pbbsident, in the Chaib. 



The minutes of the last General Meeting and of Council 
Meetings were read and confirmed. 



The following gentlemen were elected : — 

Assooiatb Mbmbeb— 
Mr. W. GoBDON Gbbbnbow, Hednesford. 

Student— 
Mr. Gavin Hildick Smith, The University, Birmingham. 



Prof. C. Lapwoeth read the following paper on ** The- 
Hidden Coal-fields of the Midlands": — 



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*:26 THE HIDDEN COAL-FIELDS OF THE MIDLANDS. 



THE HIDDEN COAL-FIELDS OF THE MIDLANDS. 

By Prof. CHARLES LAPWORTH. 



The day was when it was believed that each of the visible 
coal-fields in the Midlands was a single and complete basin in 
itself, whose coal-seams and associated strata had no relation to 
those of the other visible coal-fields of the region. But that 
primitive opinion had long since been disproved by the advance 
of geology ; and the view now generally accepted, even among 
those who have only a passing acquaintance with the science, is 
that all the visible coal-fields are simply the exposed coal-bearing 
portions of what once was a continuous sheet of Carboniferous 
strata, originally laid down in one and the same grand area of 
deposition, and afterwards covered by a similarly continuous 
sheet of red Triassic rocks. These two rock-sheets, the dark 
Carboniferous below and the red Triassic sheet above, became 
bent and folded by earth-crust movement into broad arches and 
troughs. From the crests of these arches, the Triassic rocks 
have been swept off by denudation, laying bare the Coal-measures 
below. These bared portions now form the visible coal-fields. 

But, in the broad troughs and depressions between these 
arches, the red rocks of the Triassic sheet still remain intact, 
while beneath that sheet, at depths which increase, bix)adly 
speaking, in passing outwards from the visible coaJ-fields towards 
the central parts of the depressions, the Coal-measure sheet is 
presei-^^ed, and forms an enormous hidden coal-field or coal-fields 
underlying all the country intervening between one visible coal- 
field and another. 

This newer generalization is certainly a great advance upon 
the older one, and it has, at all events, the advantage of bringing 
into prominence one of the chief economic results of geological 
mapping and research among the Midland Coal-measures during 
the last 50 years, at the same time that it indicates, in a broad 
way, the mode of origin and the present relations of the visible 
and the hidden coal-fields of the district. 



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THE HIDDEN COAL-FIELDS OF THE MIDLANDS. 27 

But while this view is adequate enough as a working 
generalization, it is insuificient if the details be examined; for 
it takes no account of the minor complications which enter 
into the matter. The Coal-measure sheet is by no means 
uniform everywhere either in character or in thickness ; for, in 
the northern parts of the Midlands, as in Lancashire and Xorth 
Staffordshire, the Coal-measures are a mile in depth and their 
middle member is exceedingly rich in workable coal-seams, while 
towards the southern parts the sheet becomes much thinner and 
finally all that remains is a mass of sandstones and shales from 
which coal-seams are absent or, if present, are thin and poor. 

The red Triassic rock-sheet certainly overlies the dark sheet 
of the Coal-measures wherever the two are found in association, 
but there are large districts of country, like some near Charn- 
wood, where the Coal-measure sheet was swept off before the 
Triassic sheet was laid down, and where, as a consequence, 
hidden coal-fields cannot possibly be met with. 

It is true that a visible coal-field, like that of South Stafford- 
shire, may occur on the crest of a denuded arch and be every- 
where more or less surrounded by the Triassic rock-sheet with 
its promise of hidden coal-fields. But there are far more cases 
where, as in Xorth Staffordshire, the visible coal-field lies on one 
of the flanks of an arch, or, as in the county of Denbigh, lies on 
the outer rim of the region, so that the Triassic rocks occur on 
only one of its sides. Again, even where the visible coal-fields 
are fringed by Triassic rocks with hidden coal-fields below, 
these hidden coal-fields are sometimes cut off by faults of enor- 
mous throw, like the boundary-faults of the Black Countiy; 
faults sometimes so great as to deter mining enterprise 
beyond them down to the present time, as in the case of the 
great red-rock fault of the Potteries country. 

If, however, allowances are made for such difliculties 
and complications, the generalization stands. All the produc- 
tive Coal-measures of the Midlands are constituent parts of 
what once was the same sheet of ordinary sediments ; and, where 
they now remain preserved under the newer formations, they 
form a series of hidden coal-fields collectively larger than all 
the visible Midland coal-fields combined. 

The story of the gradual accumulation of our present know- 



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28 THE HIDDEN COAL-FIELDS OF THE HTDLANDS. 

led^e of the Midland Coal-measures, visible and hidden, reaches 
far back into the earlier half of the last century. To no British 
geologist does the present acceptance of the view, that all the 
Coal-measures and their coal-seams are ordinary sediments and 
follow the wellknown laws of deposition, arrangement and 
continuity of such sediments, owe more than to the late 
Prof. J. B. Jukes, whose memoir on the South Staffordshire coal- 
field* still remains classic. The detailed mapping of the coal- 
fields and their surroundings by the ofiicers of the Government 
Geological Survey has shown how naturally the characters and 
distribution of the Carboniferous formations and subformations 
fall into line and order under this simple view. It lies at the 
foundation of the inferences drawn by the geologists of the First 
Boyal Coal Commission in all that concerns the probable posi- 
tions and resources of the concealed coal-fields then untested; 
and all the underground extensions of our coal-fields won or 
proved since that time fall within the areas then suggested. 
The brilliant discoveries and speculations, made by our latest 
generation of Carboniferous geologists — Messrs. Walcot Gibson^ 
Thomas Crosbee Cantrill, Wheelton Hind, John Thomas Stobbs 
and Percy Fry Kendall — during the last few years, go to show 
that this view is becoming applicable to yet finer and finer 
detail. Indeed, the day has now arrived when, not content 
with establishing the original continuity or otherwise of the 
subformations of the Coal-measures, geologists will make an 
endeavour to fix the details of the extent and range of the 
smaller zones, and it may be of maoy of the individual coal- 
seams themselves. 

The Midland mining community has been by no means slow 
to follow up the results of geological discovery and speculation, 
and to extend its mining enterprise well outside the limits of 
the visible coal-fields into the hidden coal-fields beyond. The 
late Mr. Henry Johnson might almost be called the British 
pioneer in this respect, and his conquest of the hidden coal-field 
of Sandwell in 1874 was as bold and startling at the time as it 
was successful in its results. In South Staffordshire alone, the 
total area of hidden coal-fields below the red ground already 

• "On the Geology of the South Staffordshire Coal-field," by Prof. J. Beete 
Jukes, MuHtum of Practiced Geology and (reolotjical Survey : Records of the School 
of Min€f< and of Science applied to the ArtM, 1853, vol. i., page 149. 



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THE HIDOEN COAL-FIELDS OF THE MIDLANDS. 29 

practically proved by workings, shafts or borings in the Cannock 
Chase country to the north, the Sandwell-Hampstead-Langley 
ground to the east, and the Baggeridge-Four Ashes country to 
the west, may be roughly set down as almost equal to one-third 
of the total extent of the original visible coal-field itself. During 
the last 50 years also, the mining community of Leicestershire 
and East Warwickshire have doubled the previously known 
•extent of their coal-mining country by opening out the hidden 
Coal-measures below the red ground ; and the hidden coal-field, 
claimed by mining authorities as already proved, below the 
red ground to the east of the Yorkshire-Nottinghamshire coal- 
fields, amounts to more than 500 square miles. 

But if geologists are right in the conclusions that they draw 
from the facts won by their researches, the total area of the 
hidden Midland coal-field hitherto entered upon, or even fairly 
proved by shafts or borings, is but a fraction of that which 
actually exists. As the output of coal increases and the 
visible coal-fields begin to show signs of exhaustion, two ques- 
tions become more pressing year by year: — (1) Where do the 
untested hidden coal-fields occur; and (2) which among them 
are 80 situated and so prolific in coal-seams that they offer the 
greatest promise of commercial exploitation and profit? 

The answers to these questions, so far as they can be answered 
in the present state of geological knowledge and engineering 
practice, are fully set forth in the various local reports of the 
recent Royal Commission on Coal-supplies which deal with the 
coal-resources of the proved coal-fields, and in the General 
Report on the Concealed Coal-fields prepared for Lord AUerton 
by the Geological Committee.* The reports, published singly, 
at low prices, should be studied by all who are interested in the 
subject. It is only necessary, therefore, to summarize the 
present state of knowledge and speculation so far as the Midlands 
are concerned, and refer to these reports for details. 

The original boundaries of the area of deposition in which 
the Midland Carboniferous strata were laid down are unknown, 
but the main or productive Coal-measures apparently die out 
altogether towards the south along a curved line drawn from the 

• Fined Report of the Boyal Commission on CocU^upplies, 1905, parts ii. to ix. 
incluBive. 



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30 THE HIDDE>' COAL-FIELDS OF THE HUDLAXDS. 

Wash, to the south of Leicester and Corentry, and thence 
through the Lickey Hills, the Forest of Wyre, and the Clee 
Hills, to the Long^mynd. This line may be looked upon as 
broadly marking the effective southern limit of the region. 
Eastwards, the area appears to have extended through Lincoln- 
shire to the shores of the German Ocean, and westwards its 
deposits still survive as far as the hills of the counties of 
Denbigh and Flint. Northward, the region includes at least 
all the southern parts of the Pennine chain from about the 
latitude of York. Within the limits of the Midland region, 
thus extended, lie the visible coal-fields of Lancashire, York- 
shire, Nottinghamshire, North Staffordshire and South Stafford- 
shire, Leicestershire, East Warwickshire, Coalbrookdale, 
Denbigh and Flint, and a few others of minor note. 

The typical district of the Coal-measures of the Midlands is 
the coal-field of North Staffordshire, where the strata have been 
mapped and studied in detail by the officers of the Geological 
Survey and by various local geologists. They have been 
recently classified and described by Mr. Walcot Gibson in the 
Survey Report on the North Staffordshire coal-field* and their 
correlation has been discussed by him and others in various 
geological papers and memoirs. According to these authorities, 
the Coal-measures of North Staffordshire attain a thickness of 
from 5,000 to 7,000 feet. For the present purpose, they are most 
conveniently regarded as being made up of two main divisions : — 
A Lower Coal-me«asure group, which may be called the 
productive Coal-measures, as they contain nearly all the work- 
able coal-seams of the district; and an Upper group, which may 
be called the non-productive Coal-measures, for although they 
contain occasional coal-seams, these seams are thin and of but 
little commercial value. 

The productive Coal-measures are sometimes regarded as 

falling into two sections: — A lower section broadly referred to 

as the Lower Coal-measures, and a higher section broadly 

referred to as the Middle Coal-measures. The section of the 

Middle Coal-measures contains the richest seams of coal in the 

district, and its highest band is that known locally as the Bassey 

mine. 

• Meirwira of the Geological Sun^ef/ of England and Wales : Hie Geology qf the 
Xorth Staffonlnhire Coal.Jiddy by Mr. Walcot Gibson, 1906, pages 38 to 65. 



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THE HIDDEN COAL-FIELDS OF THE MIDLANDS. 31*; 

The non-productive Coal-measures which follow have a 
collective thickness of 2,000 feet, and are more usually referred 
to as the Fpper Coal-measures. They are arranged in four 
successive gix)ups : — (1) Black-band group at ilxe base, from 
300 to 450 feet thick ; sandstones and mottled clays, with a few 
very thin coal-seams and many rich ironstones. (2) Etruria 
Marls, from 800 to 1,100 feet thick; mottled and purple marls 
and clays, with coarse green grits and sandstones. (3) New- 
castle- under -Lyme group, from 300 to 350 feet thick ; grey 
sandstones and shales, with four thin seams of coal. (4) Keele 
series, over 700 feet thick ; red and purple sandstones and clays, 
with rare and thin coal-seams. The Keele beds were formerly 
mapped as Permian, but they are now classed as the highest 
member of the non-productive or Upper Coal-measures. 

Mr. AValcot Gibson and others have shown within the last 
few years that the whole of this non-productive series forms a 
geological unit, and must in future be looked upon as such. 
Its four divisions are all conformable among themselves, and 
graduate the one into the other. They all contain intermittent 
coal-seams, although these are of little value. From the bottom 
to the top of the series, there is a recurrence of thick beds 
of brightly coloured clays and marls, of thin limestones 
with Entomostraca and occasional examples of Spirorbis, the 
Spirarbis'hsinds becoming more important towards the summit 
of the series. Xot only is this non-prcKluctive series thus shown 
to be a definite Coal-measui-e series following naturally after the 
productive Coal-measures, but its distinction from the true Per- 
mian beds has been made evident by the discoveries in East 
Nottinghamshire. In a boring* at Thurgarton, 10 miles north- 
east of Nottingham, these non-productive Coal-measures were 
found to underlie unconformably the typical Permian rocks of 
that district. These true Permian rocks there consist of the 
Magnesian Limestone series. Below the unconformable base 
of this series were met in descending order: — (1) 188 feet 
of red sandstones and marls containing Carboniferous plants : 
answering to the Keele beds; (2) grey sandstones and shales 
containing a thin seam of coal : answering to the Newcastle 

* "On the Character of the Uoper Coal-meafmres of North Staffordshire » 
Denbighshire, South Staffordshire ana Nottinghamshire ; and their Relation to 
the Prodnctive Series," by Mr. Walcot Qibson, Tfie Qnarttrly Journal of the 
Geological Society of London^ ]901, yol. lyii., pages 202 to 264. 



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•92 THE HIDDEN COAL-FIELDS OF THE MIDLANDS. 

group; and below these (3) the ordinary grey Coal-measures of 
the visible coal-field. Thus, the non-productive series of North 
Staffordshire, including the Keele beds or the so-called Midland 
or Salopian Permian, was shown to belong to the Carboniferous 
•system by its conformity with the productive Coal-measu!re8 
beneath, and to be distinct from the true Permian by its uncon- 
formity with the Magnesian Limestone series above. 

In the Lancashire coal-field, the productive coal-measures 
have a thickness varying from 4,000 to 6,000 feet. The non- 
productive measures are also well developed, attaining a 
thickness of from 1,600 to 3,500 feet; but, as yet, their com- 
ponent divisions have not been worked out. 

In the Denbighshire and Flintshire coal-fields the productive 
Coal-measures are thinner than in North Staffordshire, but the 
thickness of the non-productive measures is greater. The Black- 
band series, at the base of the latter, has not yet been identified 
in the Denbigh district, but the Newcastle group, the Etruria 
Marl series and the Keele beds are all present and fully 
developed.* 

In the South Staffordshire coal-field, the productive Coal- 
measures are well represented, as are also the non-productive 
measures above. The productive Coal-measures attain a thick- 
ness of nearly 2,000 feet in the northern part of the coal-field, 
but thin down to a fourth of that thickness perhaps in the 
Dudley and Oldbury district, and die out apparently altogether 
as they approach the Lickey Hills. The non-productive series 
is collectively thicker than in North Staffordshire. The Etruria 
Marls of North Staffordshire are represented by the Brick-clay 
series of Oldbury, with its included green and grey Espley 
grits: the Newcastle series by the Halesowen sandstone group; 
and the terminal red-rock group or Keele series is represented 
by the so-called Permian sandstones and marls of the Lickey 
Hills, Warley and Enville. 

In the Warwickshire district, the productive Coal-measures 
decrease from more than 1,000 feet in the northern parts of the 
coal-field to less than half that amount where they are lost to 
sight near Wyken and Coventry. The Etruria Marls are 

• •* On the Character of the Upper Coal-measures of North Staffordshire, 
Denbighshire, South Stiiffordshire and Nottinghamshire; and their Relation to 
the Productive Series," by Mr. Walcot Gibson, The Qttarttrly Journal of the 
(itdogical Socuty of London, 1901, vol. Ivii., pages 260 to 261. 



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THE HIDDEN COAL-FIELDS OF THE MIDLANDS. 38 

represented by the Waxwickshire Brick-clay group, worked for 
brick-making' near Stockingford and marked by the occurrence 
of the usual Espley beds. The Halesowen group is represented 
by certain grey sandstones and coloured clays, which follow in 
the Stockingford country and have the usual Spirorbis-hsLiLds at 
the summit. The Keele series is here more fully developed 
than in any other district in the Midlands. These beds include 
most, if not all, of the strata hitherto laid down on the Geo- 
logical Survey maps as Permian: they spread out over all 
the ground lying to the west and south of the coal-field from 
Kingsbury to Kenilworth and Leamington, and are estimated to 
have a maximum thickness exceeding 2,000 feet. 

In the Coalbrookdale region, the productive CoaJ-measures 
t)r " sweet coal " group, as they are locally called, are relatively 
thin, about 220 feet at the most. They are followed by a series 
of non-productive measures, consisting of grey sandstones and 
coloured marls, with a few thin sulphurous coals and some 
Spirorbis-hdinds. By many authorities, including Mr. Daniel 
Jones and Mr. W. J. Clarke, this non-productive series is 
regarded as lying unconformably on the productive measures ; 
and it certainly overlaps south-westwards directly upon the 
old pre-Carboniferous floor. The same relations of overlap or 
unconformity also obtain throughout the whole of the southern 
extension of the Coalbrookdale region down the Severn and into 
the Forest of Wyre, where the sweet coals have been recognized 
only in one small district near Highley. All the rest of the Car- 
boniferous ground is apparently occupied by the Upper 
Ooal-measures with their sulphurous seams and local bands of 
JSpirorbisAimestone. 

In the coal-fields of Lebotwood and Shrewsbuiy, the Upper 
Coal-measures alone appear to be present. A few hundreds of 
feet of grey sandstones and shales, with a few thin coal-seams 
and Spirorbis-hoinds rest at once upon the pre-Carboniferous 
floor, and these grey beds graduate conformably upwards into 
the red sandstones and mai*ls hitherto mapped as Permian, but 
which are, the writer imagines, the representatives of the Keele 
-series of the north. 

In the East Leicestershire coal-field, no Upper Coal-measures 
appear to be present. This is also the case in the visible portion 
of the Nottinghamshire coal-field; but, as has already been 

▼OL.3CXXIII.-IMft.1W7. 3 



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84 THE HIDDEN COAL-FIELDS OF THE MIDLANDS. 

seen, they come in to the south-eastwards in the hidden coal- 
field under the post-Carboniferous cover, as proved in the boring 
at Thurgarton. 

Even from this hasty summation of the present knowledge 
of the grouping and extent of the Coal-measures of the Midland 
coal-fields, it is evident that these Coal-measures as a whole 
were laid down in one and the same grand region of deposition. 
Judging from the fact that the productive measures are thickest 
at the north of this region and thin away and finally die out at 
the south, the area must have been one in which the rate of 
depression was much more rapid in the north than in the 
southern direction. It would almost appear, indeed, that during 
Lower and Middle Coal-measure times the southern margin of 
the region remained above water. During the Upper Coal- 
measure period, however, the depression seems to have been a 
more general one, for the Upper Coal-measures appear not only 
to have been deposited upon all the productive measures in the 
central parts of the area, but to have overlapped them for some 
distance in the southern pai*ts, so as to rest directly upon the 
old Coal-measure floor along and beyond the southern margin 
of the region. 

It can hardly be expected that the physical conditions 
which obtained during Coal-measure time in the Midland area 
were altogether quite so simple as this broad generalization 
would imply. Indeed, the relations of the Upper Coal-measures 
to the productive series in Shropshire and elsewhere seem to be 
incapable of interpretation, except upon the view of local eleva- 
tion and erosion in inter-Carboniferous times, and there are 
many other difficulties which still remain to be explained. 
Nevertheless, for the sake of convenience of description and dis- 
cussion, it may be assumed that at the close of Carboniferous 
time the productive Coal-measures extended in a continuous 
sheet over the whole of the Midland region almost to its 
southern borders and the non-productive Coal-measures far 
beyond. After the close of the Upper Coal-measure time, how- 
ever, and previous to the commencement of the Trias, the base- 
ment floor of the whole of the CaTboniferous region of the 
Midlands, together with all the sedimentary sheets which had 
been deposited upon it, became warped up by earth-crust move- 



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THE HIDOEN COAL-FIELDS OF THE MIDLANDS. 



8S 



<0 



I I 



meats into broad arches or ridges, separated by intermediate 
troughs or basins. From the highest of these elevations, the 
Coal-measures became denuded, and in some districts the 
denudation progressed so far that the Coal-measures were 
stripped off the crests and flanks of the elevations and the pre- 
Coal-measure floor laid bare. In the broad hollows and basins, 
however, lying between the main elevations, the Coal-meaaures 
remained preserved: the thickness left being more or less in 
proportion to the width and depth of the basin. 

To this epoch of vigorous movement and erosion succeeded 
the long period of slow and more or less regional depression 
in which the 
thick cover of 
Triassic and suc- 
ceeding forma- 
tions was laid 
down over the 
whole of the 
Midland area, 
over denuded el- 
evations and un- 
denuded basins 
alike. 

Finally came 
the more recent 
period of re-el- 
evation and de- 
nudation, which 

apparently lasted from early Tertiary time down to the present, 
during which the red -rock cover has been again partly stripped 
off the country and the Coal-measures laid bare over large areas. 



**' 



UJ 



o 

A 



y 



>? 



'1- "j: 



^ 



■y. 






o 



50| 



'^th 



MID -STAFFORDSHIRE 
BASIN , 

5 *^- is I 



^^.. 



-,^ 



£Z 






! "5 









Fio. 1.— Diagrammatic Flak of Anticlines and Basins 
OF Southern Midlands. 



In order to appreciate the present distribution and relation- 
ships of the visible and hidden coal-fields of the Midlands, it 
is necessary to bear in mind the arrangement of the great arches 
and troughs into which the Carboniferous rocks and the over- 
lying sediments have been warped. 

The chief arch or anticline — the Pennine arch — enters the 
Midland region from the north, and comes down towards the 
centre of the area beyond Cheadle and Derby (fig. 1). This 



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86 THE HIDDEN COAL-FIELDS OF THE MIDLANDS. 

arch dies down to the east into the Nottinghamshire basin, which 
is broad and shallow and has its outer rim in East Lincolnshire 
along the shores of the German ocean. The Pennine arch sinks 
down similarly to the west into the corresponding, but much 
narrower and deeper basin of Cheshire, whose outer rim lies 
along the high grounds of Denbigh and Flint. To the south, 
the great arch dips into the Mid-Staflfordshire basin, which 
extends east and west almost from Nottingham to Cheshire. 

A second but smaller arch — ^the South Staffordshire anti- 
cline — enters the Midlands from the south, and is prolonged 
northwards in its turn almost to the centre of the Midland 
region. This arch splits the southern parts of the Staffordshire 
basin into two long bays or troughs : — The Wolverhampton sub- 
basin and the Birmingham sub-basin. East of the Birmingham 
basin is the broad and irregular Leicestershire platform, which 
shows coal-fields emerging here and there from beneath a ragged 
red-rock cover, and is prolonged to the north-west below the red 
ground as a barren underground ridge — the Melbourne-Derby 
ridge — extending to the Pennine arch and separating the Stafford- 
shire and Nottinghamshire basins. West of the Wolverhampton 
basin lies the corresponding Shropshire platform, which has lost 
practically all its former Triassic cover, and is similarly prolonged 
to the Pennine arch as a subterranean, but perhaps coal-bearing, 
ridge — the Newport-Drayton ridge — separating, along much of its 
course, the Staffordshire and Cheshire basins. 

The visible coal-fields of Nottinghamshire, North Staffordshire, 
Lancashire and Cheshire flank the Pennine arch where it sinks 
down into the Nottinghamshire, Staffordshire and Cheshire basins. 
The coal-fields of Denbigh and Flint lie along the western border 
of the Cheshire basin, and those of Shrewsbury and Lebotwood 
along its border to the south. The coal-fields of Ashby-de-la- 
Zouch rest upon the main body of the Leicestershire platform, 
those of the Clee Hills on that of the platform of Shropshire, 
and the coal-field of Dudley on the crest of the South Stafford- 
shire anticline. The coal-fields of Coalbrookdale and Forest 
of Wyre lie along the line where the Shropshire platform sub- 
sides below the Wolverhampton trough, and the coal-field of 
East Warwickshire where the Leicestershire platform dies down 
into the Birmingham basin. 

The visible coal-fields of the Midlands occur, as a rule, on 



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THE HIDDEN COAL-FIELDS OF THE MIDLANDS. 87 

the flanks of the great arches and elevations. The hidden coal- 
fields lie buried under the Triassic cover which overspreads the 
intermediate basins. Where the elevations slope very gently 
into the basins, as in Warwickshire and East Nottinghamshire, 
the prolongation of the coal-seams under the red ground can be 
followed, stage by stage, outwards from the visible coal-field 
itself. This can be done in three ways: — (1) By working the 
coal-seams, foot by foot, from the collieries inside the visible 
coal-field, deeper and deeper under the red ground. (2) By 
sinking trial borings in the red ground, in advance of the 
workings, and proving the existence of Coal-measures prepara- 
tory to sinking a shaft. Or (3) by boldly sinking a shaft in 
the red ground into the hidden Coal-measures below. 
By these three methods, employed either singly or in combina- 
tion, large areas of coal-bearing ground have been won from 
the collective area of the hidden coal-fields of the Midlands 
during the last 50 years, and have been added as proved 
marginal coal-fields to the edges of the visible coal-fields of 
former days. 

The total area of the visible coal-fields in the Midland 
region may be estimated at 1,700 square miles. The total area of 
the hidden Midland coal-fields already proved is about 830 square 
miles, equal to about one-half the area of the visible coal-fields. 
But this proved ground is a fraction of the collective area 
occupied by the hidden coal-fields of the Midlands. While it is 
as yet impossible, 'aad will be so for many years to come, to 
calculate with any approach to accuracy the exact area ; yet, if a 
rough estimate be made, founded upon the assumptioti that the 
profitable Coal-measures are continued under the red rocks from 
those points where they are found sinking down under the red 
ground at the edge of one visible coal-field to the point where 
they are found emerging at the edge of another, the collective 
area of the hidden coal-fields yet to be tested may be reckoned at 
from 5,000 to 6,000 square miles. 

But this amount must be largely discounted, from the mining 
and commercial points of view, for there comes eventually 
a downward limit beyond which it becomes unprofitable to 
follow these hidden coal-fields in their underground extension 
below the Trias, no matter how promising the geologist may 
consider them to be as respects the number and quality of the 



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88 THE HIDDEX COAL-FIELDS OF THE MIDLANDS. 

coal-seams that they may contain. This liniit is fixe<l by the 
depth of their coal-seams below the present surface of the country. 
It may be true that as the depth increases the cost of extraction 
can be reduced by capitalists securing a larger area for working, 
and laying down at the commencement a plant sufficiently com- 
prehensive to cope with the corresponding increase of output. 
But broadly speaking, the eng'ineering difficulties of coal-working 
augment with the increase of depth or, in other words, with 
the thickness of the overlying cover. 

At the Florence collieries of North Staffordshire, coal is 
worked to a depth of 3,000 feet; and at Pendleton colliery, in 
Lancashire, to a depth of 3,483 feet. It is not unlikely that the 
time is fast approaching when such mines will be worked prac- 
tically to a depth of 4,000 feet; but this may be said to be the 
downward limit of profitable working, as accepted by mining 
engineers of the present day. This depth was adopted as the 
depth-limit by the Commissioners in the last two Royal Coal 
Commissions; their lead is here followed in this respect, and 
the limit of possibly profitable coal- working set down at a 
depth of 4,000 feet. 

But this downward limit has a most important bearing upon 
the matter of the unproved hidden coal-fields of the Midlands, 
and at once removes at least half the area which they probably 
occupy from the category of practical discussioiv. If the Triassic 
rocks and the underlying non-proii table Coal-measures of the 
Midlands retain the same thickness in the cores of the great 
basins as they possess along their margins, the productive Coal- 
measures in the central parts of most of these basins must be 
well below this limiting depth of 4,000 feet. 

The extension and resources of the hidden coal-fields, proved 
and unproved, as they are developed from district to district 
when followed through the Midlands, now remain to be 
considered. 

The Pennine arch of the Northern Midlands sinks very 
gently downwards towards the east and south-east into the Not- 
tinghamshire bafiin, which, according to the conclusions of Prof. 
Percy Fry Kendall, is continued eastward almost to the shore of 
the German Ocean before its outer border is reached, and south- 
ward, perhaps, to the latitude of the Wash. The Coal-measures 



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THE HIDDEN COAL-FIELDS OF THE MIDLANDS. 39 

of this basin, sls they sink downward in an easterly direction, 
are laid bare over an extent of 840 square miles, forming the 
visible Nottinghamshire and Yorkshire coal-field. Their continua- 
tion under the red rocks has already been proved by means of bore- 
holes for a distance of from 4 to 10 miles under the red ground 
beyond the limits of the visible coal-field, and they are already 
worked under the red ground by a line of shafts like those of 
Shireoaks, Warsop, Sherwood, etc., to a long distance outside. 
The total area of hidden coal-field already accepted as proved 
and added as a marginal coal-field to the visible coal-field is set 
down by Prof. Percy Fry Kendall at 570 square miles.* 

But the area over which the profitable Coal-measures extend 
as a hidden coal-field in the Nottingham shire basin is certainly far 
greater than this, and Prof. Percy Fry Kendall estimates it at 
3,885 square miles.t The Royal Coal Commissioners acknowledge 
an area of some 2,550 square miles, extending outwards from the 
Nottinghamshire coal-field under the Trias and succeeding 
formations across Nottinghamshire and Lincolnshire almost to 
the edge of the Wash, and thence north-eastward to a line drawn 
through eastern Lincolnshire to a point midway between Selby 
and Hull. Throughout the whole of this area, it is possible that 
many of the best seams of the productive Coal-measures lie 
within 4,000 feet of the surface, and will be worked in the course 
of time. This great concealed coal-field constitutes, so far as 
known, the grandest hidden coal-field in the Midlands. Its 
Coal-measures dip at such a gentle angle, and are so little broken 
by faults and folds, that they can be easily worked. Some of its 
coal-seams, like the Bamsley Hard, have a very high reputation. 
Its position, lying between the large manufacturing towns of 
Yorkshire and Nottinghamshire on the one side and the sea on 
the other, has an important bearing on the demand for its coals ; 
and its special advantages, both from the commercial and from 
the geological points of view, are certain to make it that hidden 
coal-field of the Midlands which will be most profitably and 
rapidly developed in the future. 

West and south-west of the Pennine anticline, and thus cor- 
responding in position to the Nottinghamshire basin, lies the great 

* ** Sub-report on the Concealed Portion of the Coal-field of Yorkshire, 
Derbyshire and Nottinghamshire," by Mr. Percy Fry Kendall, Final Rtport of the 
Roydd Gamrnvtifion (ni Coal-supplies, 1005, part ix., page IS. 

t liyid,, page 32. 



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40 THE HIDDEN COAL-FIELDS OF THE MIDLANDS. 

basin of Cheshire and South Lancashire. But, while the Nottingr 
hamshire basin is remarkable for its shallowness, and, as a 
consequence, for the wide spread of workable Coal-measures,, 
within 4,000 feet of the surface, the central parts of this Cheshire 
basin are of great depth, and over fully one-third of its area the 
profitable Coal-measures, if they exist, may lie deeper than the- 
workable limit of 4,000 feet from the surface. The northern 
flanks of the basin are occupied by the visible coal-field of South 
Lancashire, and, under the unworked ground lying along the 
south of the field, the Boyal Coal Commissioners estimate that 
some 105 square miles* have already afforded suificient geological 
evidence that their Coal-meausres lie within 4,000 feet of the sur- 
face, and so this area is regarded as forming a proved extension, 
of the Lancashire coal-field. On the western flanks of the basin, 
lie the Denbigh and Flintshire coal-fields, and now that the red 
so-called Permian measures of that country are grouped as the- 
Keele series in the Carboniferous, much of the area that these 
rocks occupy is looked upon as constituting a proved marginal 
extension of these coal-fields. Over all the remainder of the 
Cheshire basin, the existence of workable Coal-measures is- 
inferred by geologists. A broad sweep of country occupying a 
total area of some 200 square miles, t including the peninsula of 
Wirral and almost the whole of the ground intervening between 
the estuarj- of the Mersey and the edge of the Lancashire coal- 
field, is believed by Mr. Aubrey Strahan and others, to contain, 
coal-seams within workable depths. Into the same category also 
falls a narrow strip of red-rock country on the flanks of the 
Lancashire-Cheshire coal-field, in the district* of Manchester and 
Stockport. J But, for all the central and southern parts of the 
Cheshire basin, including the whole of the country lying between 
Shrewsbury on the south and Runcorn on the north, Congleton 
on the east and Chester on the west, no estimate has yet been 
attempted. So far as the known geological facts enable one to 
judge, it would appear that in the middle parts of this great 

* ** Report on the Available Coal-resources of District G (North Wales, 
Lancashire and Cheshire)," by I^f. Edward Hull, Sir George John Armytage,. 
Bart., and Mr. Aubrey Strahan, Final Report of the RoycU Commission <wi Coal- 
supplies, 1906, part iv., plate i. 

t ** Sub-report to the Geological Committee on the Concealed and Unproved 
Coal-fields, not including District B," by Mr. Aubrey Strahan, FincU Report of the 
RoyaJl Commission on C<Ml-supplieSf 1906, part ix., page 16. 

t Ibid., page 15, 



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THE HIDDEN COAL-FIELDS OF THE MIDLANDS. 41 

area, from Middlewich through Crewe to Wem and Whitchurch, 
there must lie from 3,000 to 4,000 feet of Triassic rocks* upon 
the Carboniferous strata below. Below these, from 1,000 to 3,000 
feet of Upper and non-productive Coal-measures may have to be 
cut through before the productive Coal-measures are reached. 
These numbers are, perhaps, extreme, but they are sufficient 
to show that under all the central parts of the Cheshire basin the 
profitable measures lie too deep for working. 

On the eastern flanks of the basin, and between it and the 
North Staffordshire coal-field, runs the great red-rock fault with 
an unknown throw, as yet completely baffling research and enter- 
prize in that direction. Along the southern and south-eastern 
margins of this basin, however, from the northern edge of the 
Shrewsbury coal-field far to the north-east, it is probable that 
Coal-measures lie under the red ground at no very great depth 
below the surface ; such Coal-measures as are seen sinking into 
the basin contain, however, but a few thin coals and these 
probably belong to the Upper Coal-measures. It may be some 
miles inside the margin of the Cheshire basin in this direction 
before the productive measures come in, and in that distance 
they may have sunk to so great a depth or under such a thickness 
of water-bearing Trias, as to make their exploitation unprofitable. 
South of the Pennine anticline, the Coal-measures sink down 
somewhat steeply into the Mid-Staffordshire basin. The north- 
eastern flanks of this basin are occupied by the strata of the visible 
North Staffordshire coal-field. Succeeding the grey measures of 
that coal-field, the band of red rocks comes in, which constitutes 
the Keele series, now classed as the highest member of the Upper 
Coal-measures. About half the width of this Eeele band of 
North Staffordshire,t having a total area of some 10 to 12 square 
miles, forms a hidden coal-field, which is held to occupy ground 
that is already sufficiently known and is regarded as the proved 
extension of the Potteries coal-field. South of this proved 
ground lies a much broader strip of country extending from 
Madeley through Stone in the direction of Cheadle, occupying 

* *< Sub-report to the Geological Committee on the Concealed and Unproved 
Coal-fields, not including District B," by Mr. Aubrey Strahan, Final Rtpwi oftht 
RoycU Commisaion mi C(Ml-supplieSf 1905, part ix., page 13. 

t ''Report on the Available Coal-resources of District B (Staffordshire, 
Warwickshire, Leicestershire, Shropshire, and a small portion of South Derby- 
shire)," by Prof. Charles Lapworth and Mr. Arthur Sopwith, FincU Beport of the 
R&yal Cammisai&n on Coal-auppHent 1906, part iiL, page 4. 



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42 THE HIDDEN COAL-FIELDS OF THE MIDLANDS. 

some 96 square miles* and floored partly by the Keele series 
and partly by the Triassie formation. In this ground it is held 
that, in all probability, the higher seams of the productive Coal- 
measures of the North Staffordshire coal-field lie within 4,000 
feet of the surface. Beyond this narrow band, however, over 
all the more central parts of the Staffordshire basin, which are 
floored by the Keuper Marls, from Eccleshall almost to Burton, 
if the productive measures occur at all, they probably lie 
at unworkable depths below the surface ; for, at Chartley, in the 
eastern i>art of this area, Keuper Marls have already been bored 
through to a depth of 2,400 feet without reaching their base,t 
and below this it may be naturally expected that the whole of 
the Bunter and some of the Upper Coal-measui-es might have 
to be pierced through before the profitable measures could be 
reached. 

Along a line running across the eastern part of the Mid- 
Staffordshire basin, from Cheadle to Repton, and continued to the 
north-eastern parts of the Leicestershire coal-field, the basement 
beds of the productive measures must crop out against the over- 
lying cover of Triassie rocks, so that a broad stretch of 
country forming the subterranean ridge of Derby and Melbourne, 
extending from this line as far eastwards as Trent Junction, 
must be destitute of Coal-measures. 

The groat Leicestershire platform extends from Burton-upon- 
Trent Bridge eastwards to Melton Mowbray, south and south- 
eastwards towards Rugby and Leicester, and westwards to Athei- 
st one and Nuneaton. Over the whole of this platform the red- 
rock cover is comparatively thin, and had the Coal-measures 
remained as fully preserved upon this platform as in the Xotting- 
hamshire basin, its hidden coal-fields would have been equally 
promising. But previous to the deposition of the Triassie cover, 
this area was broken up into comparatively narrow ridges, arches 
and folds, from the crests of which the vCoal-measures were swept 
off and the pre-Carboniferous floor laid bare. The denuded floor 
shows out at the surface in Chamwood Forest, in the Nuneaton 

* ** Sub-report to the Geological Committee on the Concealed and Unproved 
Coalfields in Diatrict B," by Prof. Charles Lapworth, Final Report of the Royal 
Commumon an Coai-Mupplies, 1905, part ix., page 7. 

t "Table and Map (plate iii.) of the more important Borings, throwing 
Light on the possible Occurrence of Concealed Coal-fields," by Messrs. Aubrey 
Btrahan and O. T. Jones, Final Report of the Royal Commission oti Coal-tnipplies^ 
1905, part ix., page 37. 



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THE HIDDEN COAL-FIELDS OF THE MIDLANDS. 48 

district, and in the Melbourne district overlooking* the valley of 
the Trent ; it lias also been met with again and again in trial- 
borings sunk through the red-rock cover, at Evington, neai* 
Leicester, Market Bosworth and elsewhere.* Nevertheless, the 
productive measures were not swept from off the whole of this 
platform, but are preserved more or less over its north-western 
parts and in certain deeper hollows to the south and south-west. 
They show throug-h at the surface as the visible Leicestershire or 
Ashby-de-la-Zouch coal-field, and are prolonged under the red- 
rock cover south-eastwards as far as Desford, near Leicester, and 
westwards to near Donisthorpe and Overseal. Much of the Coal- 
measure ground under the red rocks has already been proved by 
borings and shafts in these directions, and largely worked for 
many years past. The area of hidden coal-field, thus added as 
an extension to the previously known coal-bearing ground, is 
estimated at about 54 square miles. 

There are possibly other hidden coal-fieldst under the red 
rocks of the Lieicestershire platform, lying in narrow basins on 
the old Coal-measure floor, but such coal-seams as have already 
been met with in them, as near Hinckley and Brandon, are 
apparently thin and unprofitable. 

Yery different in all these respects is the ground on the south- 
eastern side of the Leicestershire platform, extending from Poles- 
worth through Bed worth and Coventry in the direction of Kenil- 
worth. Along this broad band of coimtry, the underground plat- 
form slopes down into the eastern side of the Birmingham basin. 
The Coal-measures show out at the surface as the visible East 
Warwickshire coal-field. The main seams of this field dip, 
at first, steeply westwards, and then flatten out and subside 
gently below the broad spread of Keele or so-called Permian 
ground, forming a hidden coal-field of very great but unknown 
extent. The enterprise of the East Warwickshire mining engin- 
eers has already proved some 34 square miles of hidden coal-field 
under the red beds, and added it as an extension to the main 
Warwickshire coal-field. The new ground has been tapped in 

* "Table and Map (plate lii.) of the more important Borings, throwing 
Light on the possible Occurrence of Ck)ncealed Coal-tieldB/' by Messrs. Aubrey 
Strahan and O. T. Jones, FincU Rtport of the Royai Commisfdon on CocU-supp/ieSf 
1906, part ix., page 39, etc. 

t *• Sub-report to the Geolosical Committee on the Concealed and Unproved 
Coal-fields in District B," by Prof. Charles Lapworth, Final Report of tht RoycU 
CcmnU99wn on CocU-JtupplieM, 1906, part ix., pages 10 to 11. 



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44 THE HIDDEN COAL-FIELDS OF THE MIDLANDS. 

colliery-workings and shafts for a distance of from 1 mile 
(Tunnel shaft, Xewdigate colliery) to 4 miles, and the continuity 
of the Coal-measures under the red rocks has been shown for a 
distance of several miles more.* How far workable Coal-measures 
may extend southwards from the ground already won, the writer 
is, as yet, unable to say ; but, judging from the manner in which, 
the coal-seams thin away towards Wyken and Craven, it caa 
hardly be expected that they will extend in workable thickness- 
far south of the latitude of Coventry-. 

A long stretch of red-rock country occupies most of the 
Birmingham basin,t lying between the East Warwickshire coal- 
field on the east and the South Staffordshire coal-field on the 
west, and ranging from Henley-in-Arden on the south to some 
distance beyond Lichfield on the north. The prolongation of the 
productive Coal-measures eastwards towards the centre of this^ 
basin has been demonstrated by the extension of the East War- 
wickshire coal-field. The fact that they are similarly prolonged 
westward from the South Staffordshire coal-field has long been 
known ; they have been mined in the collieries of Hamstead and 
Sandwell Park under the red ground for a distance of from at 
least 2 miles from the edge of the visible coal-field, and they 
have recentl3' been bored into below the red ground well to the 
south of these localities at Langley. Several square miles of hidden 
coal-field have here been already tested, and partly won. There 
is much to be said for the view that Coal-measures extend more 
or less continuously under much of the red-rock ground of this 
Birmingham basin ; but, from the commercial point of view, the 
several parts of the basin are by no means equally promising. 
It is verj- doubtful whether profitable Coal-measures occur 
south of a line drawn across the basin from Harborne to Coventry,, 
all south of that line being occupied by upper measures. 
Again, over the northern parts of the basin lying between the 
extreme north of Cannock Chase and the Leicestershire coal- 
field, the geological evidence goes to show tliat rocks older 
than Coal-measures crop out in that direction under the cover of 

* ** Report on the Available CoaUresources of District B (Staffordshire, 
Warwickshire, Leicestershire, Shropshire, and a small portion of South Derby- 
shire)," by Prof. Charles Lapworth and Mr. Arthur Sop with, FiiicU Report of the 
Royal CommisHion on CocU-sHppfieSy 1905, part iii., pages 5 to 6. 

t Ibid., part iii., pages 5 to 6 ; and '* Sub- report to the Geological Committee on 
the Concealed and Unproved Coal-fields in District B," by Prof. Churles Lapworth^ 
Fifial Report of the Royal CommU'non on Coaf -supplies, 1905, part ix., pages 9 to IC 



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THE HIDDEN COAL-FIELDS OF THE MIDLANDS. 45 

the yew Red rocks. If coal-seams are present, the measures will 
probaUy be foniid to dip and thicken towards the Lichfield 
country. 

The productive measures are perhaps in their greatest force 
along a line drawn across the basin from Aldridge towards Tam- 
worth; but they probably lie at comparatively great depths, for 
the highest member of the non-productive series — ^the Keele or 
so-called Permian — is mapped as showing at the surface at more 
than one locality, as near Four Oaks, and in a recent boring at 
Streetly its thickness was found to be great. Promising 
as this ground appears to be from the geological point of view, 
the great but unknown throw of the western boundary fault on the 
one side and the Tamworth faults on the other have hitherto 
acted as effectual deterrents to mining speculation in this 
country. 

West of the Birmingham basin runs the long and narrow 
South Staffordshire anticline and its visible coal-field.* From 
the crest of this arch, over an extent of some 105 square miles, 
the red-rock cover has been removed, laying bare the underlying 
Coal-measures and giving origin to the visible South Staffordshire 
coal-field. West of the visible coal-field lies the Wolverhampton 
basin, answering in its way to the Birmingham basin on the 
opposite side. Eastward, the coal-field is limited by the eastern 
boundary fault, and westward by the corresponding western 
boundary fault, both of very great throw. Southward, the arch 
dies down under the red rocks of the Lickey Hills, while north- 
ward it is prolonged far under the red rocks of Cannock Chase. 
To the south there is no hope of the discovery of a hidden coal- 
field, for the sinkings of Manor pit and Wassel Grove show that 
the profitable Lower Coal-measures thin out or deteriorate in this 
direction. Northward, however, the coal-seams are prolonged far 
under the red-rock cover in the direction of Stafford. The 
enterprise of South Staffordshire mining engineers has 
already proved a hidden coal-field under the Cannock Chase 
country by workings, shafts and borings to a. distance of from 
1 to 3 miles in a north-westerly direction ; and the thickness of 
the profitable measures and the collective thickness of the coal- 

* "Report on the Available Coal-resources of District B (Staffordshire, 
Warwickshire, Leicestershire, Shropshire, and a small portion of South Derby- 
shire)," by Prof. Charles Lapworth and Mr. Arthur Sopwith, Final Report of the 
Royal Commisnion on CocU-mipplieSt 1905, part iii., pages 4 to 5. 



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46 THE HIDDEX COAL-FIELDS OF THE MIDLANDS. 

seams appear both to increase in this direction, while, as yet, the 
red-rock cover has only thickened to a few hundreds of feet. It 
is not impossible that, for many miles beyond this, the workable 
measures will be found to lie within a reasonable depth of the 
surface. The beds, however, in the more northerly parts of the 
Cannock coal-field, dip to the west and south-west, so that on the 
north-east side fewer and fewer seams come in below the red- 
rock cover; and such evidence as has been obtained durin^g^ the 
last few years goes to show that on the north-eastern side of the 
Cannock Chase country the base of the Coal-measures may be 
eventually reached. 

Immediately west of the coal-field, and cutting it off from 
the Wolverhampton basin, comes the western boundary fault, 
bringing the red rocks suddenly against the Coal-measures of 
the visible coal-field. Until quite recently, the great but un- 
known throw of this fault effectually barred all coal-mining 
enterprise beyond it. But within the last twenty years, the ad- 
vance of geological knowledge on the one hand, and the certainty 
of the approaching exhaustion of the coal-seams in the visible 
coal-field on the other, have together prompted the more sanguine 
members of the coal-mining community of South Staffordshire 
to risk the venture of proving the hidden coal-fields, which should 
theoretically lie beyond it in a westerly direction. In the only 
two instances in which this venture has been attempted, it 
has met with success. The presence of Coal-measures outside 
the western boundary fault under the Triassic rocks of the 
Wolverhampton basin* has been shown at the borings of Four 
Ashes and of Baggeridge. At Baggeridge, the proof has since been 
utilized by the sinking of shafts preparatory to the commence- 
ment of colliery-workings. The total area of hidden coal-field 
thus tested outside the western boundary fault may be roughly 
set down as 10 square miles. Yet this is but a narrow 
strip along the eastern edge of the great Wolverhampton basin. 
The extent of red-rock country occupied by the basin is some 
20 miles long, from the latitude of Stafford on the north to that 
of Kidderminster on the south, and some 12 miles wide, from the 

* "Report on the Available Coal-reaources of District B (Staffordshire^ 
Warwickshire, Leicestershire, Shropshire, and a small portion of South Derby, 
shire)," by Prof. Charles Lapworth and Mr. Arthur Sopwith, Final Report of the 
BoycU Commission on CoaJ-mipplies, 1905, part iii., page 6; and ** Sub-report to 
the Geological Committee on the Concealed and Unproved Coal-fields in District 
B," by Prof. Charles Lapworth, tWt/., part ix., pages 7 to 8. 



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THE HIDDEN COAL-FIELDS OF THE MIDLANDS. 47 

boundary fault on the east to the coal-fields of CoalbrookdaJe and 
the Forest of Wyre on the west. A thickness of from 1,100 to 
2,100 feet of Upper Goal-measures shows out along the margin 
of the basin above the productive coal-seams; and farther in- 
wards this is followed by a thickness of 1,300 to 1,400 feet of 
Triassic sandstones. In the central parts of the basin, this sand- 
stone is overlain by an unknown but great thickness of Keuper 
ilarl. It follows, therefore, almost of necessity, that over the 
more central part of the basin where the Marls show at the 
surface, as in the country running north from Patshull to Eocles- 
hall, the productive Coal-measures may lie at a depth of from 
8,000 to moi'e than 4,000 feet from the surface. 

Between these more central areas, however, and the margins 
of the basin, if the productive measures are present they will lie 
at more reasonable depths. They are worked already on the 
western margin of the basin from the collieries inside the coal- 
field of Coalbrookdale, at Madeley and Oakgates, for some dis- 
tance under the so-called Permian or Keele rocks ; and the whole 
extent of this Keele country, extending almost to the town of 
Shifnal, is regarded as constituting a hidden coal-field already 
practically proved. But throughout the red-rock ground, 
forming the remainder of the western and southern sides 
of the basin, only one enterprising venture has yet been made. 
This is the boring at Claverley recently completed. It may 
reasonably be expected that, under the red-rock country, lying 
between this point and the Staffordshire coal-field in the one 
direction, and the Coalbrookdale coal-field in the other, the 
productive Coal-measures soon occur in force and in workable 
condition. 

To the south, south-east, south-west and west, matters are 
very different. The whole of the Forest of Wyre coal-field, 
forming the south-western flank of the Wolverhampton basin, 
appears to be occupied at the surface by the upper and non- 
productive Coal-measures. Only in one small area in the Forest 
of Wyre coal-field, namely, in the district of Highley, near 
Kinlet, are the productive or sweet coals known to occur below 
the Upper Coal-measures* nor, as matters stand, can these sweet 

* *< Sub-report to the Geological Committee on the Concealed and Unproved 
Coal-fields in District B," by Prof. Charles Lapworth, Final Report of the Royal 
CommiiHon on CocU-suppHeSt 1906, part ix., page 7. 



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48 THE HIDDEN COAL-FIELDS OF THE MIDLANDS. 

coals be expected in force below much of the red ground of the 
Enville country. Down the valley of the Stour, however, between 
Tettenhall and Stourbridge, they may occur in workable thick- 
ness ; but, if so, they are certainly covered by a great thickness of 
water-bearing rocks. Under the New Red Sandstone from 
Shifnal to the latitude of Bridgnorth, they may be expected to 
prove fairly well developed under the Triassic beds within a 
reasonable depth of the surface. But there is the same difficulty 
in that ground as under the Stourbridge country, for there is a 
great thickness of water-bearing rocks to be cut through and 
tubbed out before it would be possible to work them. 

On the Shropshire platform,* which occupies all the country 
lying between the Wolverhampton basin and the Welsh mountain 
border, only thin coal-seams, apparently belonging to the Upper 
Coal-measures, are as yet known to occur. This is the case both 
in the Lebotwood and the Shrewsbury coal-fielde, and this fact 
will no doubt have a very restrictive effect upon the search for 
coal under the red ground which lies to the north of them and 
sinks towards the depths of the Cheshire basin. 

There can be little doubt that, a few miles north of these coal- 
fields, the productive Coal-measures occur below the Upper Coal- 
measures ; but, as they make their appearance, the Triassic beds, 
probably rich in water, also come in above them, and thus add 
to the cost of the sinking. There is, however, one band of coun- 
try, namely, that joining the Shrewsbury and North Stafford- 
shire coal-fields, some of which looks fairly promising. The 
Keele beds of the Upper Coal-measures are mapped as showing out 
along this band at the surface, as at Child's Ercal, Plaswarden, 
and other localities, and it might be inferred that the productive 
Coal-measures occur within workable depths below. But here, 
it must be remembered that on the Shropshire side of this band 
there are no productive Coal-measures whatever below the 
Upper Coal-measures, while on the North Stafioixishire side there 
occur some 2,000 feet of non-productive Coal-measures before the 
productive Coal-measures are reached, and even this great thick- 
ness does not show the top of the barren series. Any boring, 
therefore, made along this line must, in the meantime, be looked 
upon as almost wholly speculative. 

* " Sub-report to the Geological Committee on the Concealed and Unproved 
Coal-fields in District B," by Prof. Charles Lapworth, Final Report of the Roynl 
Commismon on Coal-supplies, 1905, part ix. , pages 11 to 12. 



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THE HIDDEN COAL-FIELDS OF THE MIDLANDS. 49 

It is quite impossible, of course, to make more than the 
roughest estimate of the extent or the value of the workable 
coal-seams in the hidden coal-fields of the Midlands. In spite of 
all that has already been discovered it may be regarded as certain 
that no two independent investigators would arrive at precisely 
the same conclusions either as respects the true limits of the 
Midland region or the distances to which its individual seams 
are prolonged in a workable thickness or condition. But if, for 
the moment, the boundaries here suggested be accepted, the area 
once occupied by the productive Coal-measures may be estimated 
at about 11,000 square miles. From this, some 3,000 square miles 
of Coal-measures have been denuded away, leaving some 8,000 
square miles of country where they may still remain preserved. 
About 1,700 square miles only are exposed in the visible coal- 
fields, leaving 6,000 square miles as the total extent of country 
possibly occupied by the hidden coal-fields of the Midlands. 

Judging from the reports of the RoyaJ Commission on Coal- 
supplies, only an extent of some 800 square miles or thereabouts 
of the hidden coal-bearing area of the Midlands has hitherto been 
tested by coal-workings or by borings, and all the rest ha,s yet io 
be proved. Throughout much of this remainder the coal must lie 
at greater depths than 4,000 feet. But, if the conclusions of the 
geologists, who assisted in drawing up the reports, are well founded, 
more than 3,000 square miles of hidden coal-field lie as yet un- 
tested at less than 4,000 feet from the surface. It cannot reason- 
ably be hoped that very much of this untested ground will be 
entered upon for many years to come, and in estimating the 
promise which it holds out it must not be forgotten that, with 
every increase of depth the working becomes more difficult and 
more costly. It cannot be safely presumed that from all the hidden 
coal-fields, yet to be tested, the miner can expect to secure an 
available mineral wealth per square mile proportionate to that 
of the coal-fields already proved. 

It is well to be assured that in all likelihood the collective 
area of unproved hidden coal-fields of the Midlands, in which coal 
lies within a possible working depth from the surface, is larger 
than the collective area of the visible and proved coal-fields com- 
bined. But it will be a great misfortune if this assurance prompts 
to hasty experiment or rash speculation. The complications are 
so many that mining engineers cannot be too cautious. Geologi- 

▼oL. xxxin.-i«»-i«7. 4 



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50 DISCUSSION — ^THE HIDDEN COAL-FIELDS OF THE MIDLANDS. 

cal researchers must be taught to carry on their work into all 
branches of the subject and down to the most accurate details. 
Mining engineers must be trained to ever higher skill 
to face the growing difficulties. No speculative sinking should be 
started until the scientific and the practical evidence has been 
fully gone into, and the commercial promise of the venture haa 
been carefully weighed against the certainty of the pecuniary 
risk. 



The President (Mr. F. A. Grayston), in moving a vote of 
thanks to Prof. Lapworth for his valuable paper, said he hoped 
that the concluding remarks with regard to proving* the 
hidden coal-fields of the Midlands would be of benefit to the 
experienced mining engineer and to the student also. Perhapa 
some of those present might have an opportunity in the course 
of their career of putting into practice the valuable advice given 
by Prof. Lapworth. 

Mr. G. H. Claughton, in seconding the vote of thanks, said 
that it was in accordance with Dr. Lapworth's advice that tbe 
successful sinkings at Baggeridge were in their present position ; 
and those interested would ever be grateful to him for his help 
and co-operation. They were very fortunate in possessing a 
man of his great ability and the ready access to his great know- 
ledge. He trusted he would long be spared to them. 

Mr. Alexander Smith asked whether, as suggested by Sir 
Roderick Murchison and Prof. Hull, the old rocks might intrude 
in part of the Birmingham basin, and whether these older rocks^ 
were struck at the Sandwell Park new sinking. 

Mr. W. F. Clark remarked that he had had occasion to get 
the valuable assistance of Prof. Lapworth for boring through 
the red rocks in the Cannock Chase district, where coal waa 
eventually proved, exactly as Prof. Lapworth had feared it would 
be, that was, at such an angle that it could not be profitably 
worked. 

Mr. Henry Johnson wrote that the subject treated by Prof. 
Lapworth was of great importance to the Midlands and to 



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DISCUSSION — ^XHE HIDDEN COAL-FIELDS OF THE MIDLANDS. 61 

Birmini^Iiain in particular. He suggested, as touching the 
economic part of the subject, that as the future mining of this 
country must be at increased depths, greatly increased working- 
areas would be requisite to warrant the very large capital-cost 
of the future collieries; and consequently that the working- 
areas should not be broken by a large number of small owner- 
ships of the minerals. It would, therefore, be well for the 
Government, in dealing with any proposal for the subdivision 
of the lands into small ownerships, to have a care for the future 
mining of the country, by not hampering it by subdivision of 
the mines as well as of the lands. 



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62 DISCUSSION — EFFECTS OF ACCELERATION ON WINDING-TOEQUES. 



THE MINING INSTITUTE OF SCOTLAND. 



GENERAL MEETING, 

HXLD IN THB TSOHNIGAL COLLBOB, GUkSGOW, FbBEUABT IStH, 1007. 

Db. ROBERT THOMAS MOORE, Pbbsident, in thk CaAiB. 

The minutes of the last General Meeting were read and 
confirmed. 



Office-bearers for the session 1907-1908 were nominated, and 
Auditors were appointed to examine the Treasurer's accounts 
for the past year. 



The following gentlemen, who had been duly nominated, 
were elected : — 

Mbmbbbs— 
Mr. John Black Boyd, P.O. Box 262, Johannesburg, TranavaaL 
Mr. Thomas R. Gillbspik, Blantyre Collieries, Blantyre. 
Mr. KiBKWOOD Hbwat M*Nkill, Island View, Ballycastle, County Antrim. 
Mr. Thomas Smith, Fembank House, Kelty. 

Associatb Mbmbebs— 
Mr. WiLUAM Eylb, Winohburgh. 
Mr. Adam Mubdoch, Baokus and Johnston Company, Casapalca, Peru. 



DISCUSSION OF MR. GEORGE XESS'S PAPER ON 
"EFFECTS OF ACCELERATION ON WINDING- 
TORQUES, AND TEST OF TARBRAX ELECTRICAL 
WINDING.PLANT."* 

Mr. T. Lindsay Galloway (Glasgow) said that the members 

were very much indebted to Mr. Ness for placing before tbem 

definite facts as to the amount of current consumed by this 

winding-plant, which was the first electrical winding-plant in 

• Trans, hist. M. E,, 1906, voL xxxii, page 287. 



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DISCUSSION — EFFECTS OF ACCELEBATION ON WINDING-TOBQUES. 58 

Scotland. It would be observed that the test lasted for a little 
over 2 hours, and during that time, 117 winds were made, the use- 
ful load being 12^ cwts. Mr. James Caldwell stated that the useful 
load for which the plant was designed was about 25 cwts.* He 
thought, therefore, that it might be interesting to know why 
the tests were made with a load of 12^ instead of 25 cwts., as 
it was remarked by Mr. Ness in his paper that that circumstance 
was unfavourable to the testing of the plant. He observed, 
further, that ihe power-consumption, at the switchboard, was 
0'541 imit per wind;t and they were also told that the con- 
sumption of direct current as between the motor-converter or 
flywheel motor and the winder was 0*2603 unit per wind.J 
He wanted to know whether he was correct in assuming that the 
actual consumption of power as delivered from the main was 
0*541 unit per wind, and that 0*2603 unit was the consumption 
of direct current as between the motor-converter and the wind- 
ing-engine. Mr. Xess remarked that the latter figure repre- 
sented an efficiency of 48J per cent., but if they compared the 
useful work in lifting shale with the power taken at the switch- 
board, the efficiency was only 41 per cent. He thought that 
most steam winding-engines, with a mechanical counterbalance, 
would show at least as high a result. Of course, they had to 
bear in mind that the plant was not working at its full capacity, 
and when that happened they could not expect to get the 
same efficiency from it as when it was working at full power. 
The members had not been informed as to the first cost of this 
plant, but Mr. Ness had supplied an estimate of the cost of a 
similar installation, amounting* to £5,633 or, omitting the dupli- 
cation of certain parts, to £4,633. This amount would, he thought, 
be regarded as a most liberal estimate for a steam winding- 
plant capable of drawing 650 tons from a depth of 420 feet. 
When all the circumstances were considered, the members might 
ask themselves whether the use of electricity for winding was 
advisable and worth such an expenditure. The point had often 
been raised by members that, if they had to apply a steam- 
engine to create electricity and then utilize that electricity for 
winding, they ought rather to employ the engine direct 
and wind with 8t«am instead of utilizing electricity. In the 

♦ TroM. Inst. M. E.y 1906, vol. xxxi., page 227. 

t /&i(i.,1906, voL zxxii., page 290. t ^^^^ ^^06, vol. xxxii., page 291. 



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54 DISCUSSION — EFFECTS OF ACCELERATION ON WINDING-TOEQUES. 

case of oil-works, where, if he was rightly informed, there was 
a large quantity of waste heat, which could be utilized for the 
production of electricity, it seemed economical to utilize it 
for that purpose. Power-supply companies were being estab- 
lished all over the country, and the day might come when 
collieries, instead of creating their own power, would take it 
from the general supply-mains. In that event, they would have 
to face the question of electrical winding. Consideration must, 
he thought, be paid to the possibility of reciprocating winding- 
engines becoming obsolete. Steam-turbines had been found to 
be much better suited for generating electricity, when the size 
was sufficiently large, than reciprocating engines. Looming 
in the near distance, they had the suction-gas engine. If either 
of these types of engine came to be adopted at collieries, they 
would probably entail electrical winding. Personally, he 
thought that they had not seen the last of this subject, and it was 
one which the members ought to keep before them. 

The "President (Dr. Moore) asked whether Mr. Ness could 
state the proportion that the work done in lifting 650 tons of 
shale, from a depth of 420 feet, bore to the amount of power 
generated in the cylinders of the steam-engine. 

Mr. George Ness said that Mr. Caldwell had stated that 
the plant had been made for an output of 25 cwts. per wind ; 
and it was the case that the test which he had described in his 
(Mr. Ness's) paper had been made with an output of only half 
that amount. He was not able to enter into the exact reasons 
governing this circumstance further than this, that when the 
test was made the plant had to be taken oS the contractor's 
hands; and, owing to various causes, the test was made at a 
period when the full output could not be obtained from ihe 
mine. The number of units delivered at the switchboard was 
0*541 per wind ; and this was employed in transforming the 
current from three-phase alternating to continuous current in 
the flywheel converter. The total current of 0'2603 unit per 
wind, sent from the flywheel motor-dynamo into the motor, 
wound the cages; and it was quite independent of the current 
taken to excite the fields of the winding-motor, which was 
included in the total of 0*541 unit. 

A large amount of energy was lost by the friction of the 



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DISCUSSION EFFECTS OF ACCELERATION ON WINDING-TORQUES. 65 

fl5rwlieel in the air. A plant was running at the Clydebank 
Dock, belonging to the Clyde Trust, where the same principle 
was in operation. There was, however, this exception that there 
was more than one winding motor getting power from the 
flywheel converter, the flywheel was run in a vacuum, and 
the shaft was carried on roller^bearings. 

The stated efficiency of (100 x(V2603-r 0-541 or) 48i per cent. 
WA6 the calculated efficiency of the electrical plant under the 
conditions existing during the test, but he (Mr. Ness) was of 
opinion that the total efficiency considered in terms of shale 
lifted, compared with the total energy put into the system, would 
be about 47 per cent. 

The total energy employed in lifting 12^ cwts. to a height 
of 420 feet in 26 seconds would be [ (12i x 112 x 420) -f (550 x 
25)=] 42-76 horsepower. The consumption of 02603 unit per 
wind was equal to [(0-2603 x 1,000 x 60 x 60) -f (25 x 746) = ] 50*24 
horsepower. The efficiency, in terms of the energy put into the 
armature of the winding motor, was, therefore, (100x42*76-=- 
50-24=) 8511 per cent. 

Referring now to the current delivered at the switchboard, 
the total energy put into the system was 0'541 unit. Now, the 
number of winds was 117 in a period of 140 minutes, or at the 
average rate of one wind in 71"8 seconds. This point would be 
referred to later, as there was no intention to cloud the issue as 
to the useful efficiency in any way, and in the meantime, 0*541 
ttnit would be taken as consumed during the actual period of the 
wind of 25 seconds. A consumption of 0*541 unit in 25 seconds 
represented a total energy of 104*28 horsepower, and the useful 
efficiency was (100 x 42*76 -r 104*28 = ) 41 per cent, as stated by 
Mr. GhiUoway. 

How then was this 41 per cent, to be reconciled with the 
former statement that the whole efficiency was about 47J* per 
cent? It would be remembered that the plant was designed to 
make a wind every 55 seconds. Owing to the development of 
the mine at the time of the test, allowing of a load of only half 
the estimated amount, namely, 12^ cwts. per 71*8 seconds, instead 
of 26 cwts. per 55 seconds, the time taken for decking 
purposes was 46*8 seconds instead of 30 seconds. This necessi- 
tated the flywheel converter and auxiliaiy plant running an 
♦ Trans, InjU, M, E., 1906, vol. xxxii., page 105. 



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56 DISCUSSION EFFECTS OF ACCELERATION ON WINDING-TOEQUES. 

additional period of 16*8 seconds between the winds. The 
difference between the unit (02603) consumed in actual wind- 
ing, and the unit (0*541) at the switchboard, represented the 
losses due to friction, heating and field-excitation during the 
period when the plant was not performing useful work. This 
difference, amounting to 0*2807 unit., spread over 71*8 seconds, 
gave, over one second, a power-consumption of (0'2807-f71'8 = ) 
00039 unit. He had previously stated that the observed power- 
consumption, when the winder was at rest, was 15 kilowatts,* 
and this, divided by 3,600 seconds, gave a consumption of 0*0041 
unit over 1 second or an observation-difference of 0*02 per cent. 
If the lesser figure, 0*039 unit, were accepted as correct, it might 
be assumed that the plant was penalized, by the prolonged deck- 
ing period of 16*8 seconds above that estimated, to the extent of 
(00039 unit X 16*8 = ) 006552 unit. Substracting this amount 
from the 0*541 unit delivered at the switchboard, the total units 
which would have been delivered to the plant, if the estimated 
period for decking purposes of 30 seconds, had been adhered to» 
were 047548 unit, giving an electrical efficiency of (100 x 0*2603 
^0*47548 = ) 54*74 per cent. Again, taking 0*47548 unit as con- 
sumed during the winding period of 25 seconds, representing a 
total energy of 91*59 horsepower, the useful efficiency was 
(100x42*76^91*59 = ) 467 per cent. 

It might be shown by a reductio ad absurdum, that this reason- 
ing was based on absolutely fair lines, without prejudice either 
in favour of or against this system of electrical winding. Suppos- 
ing a wind to be made, after which the flywheel converter con- 
tinued to run on for 2 houra before the next wind took place. The 
consumption by observation to run the flywheel converter idle 
was at the rate of 15 units per hour, and would, therefore, for 2 
hours, be 30 units -i- 0*47548 unit taken in winding. If this were 
considered from the point of view of useful work in lifting 
shale, there would be a total consumption in the 25 seconds' 
period of winding of 30*47548 units, or energy at the rate of 
1*219 units per second, or 5,882 horsepower; and the useful 
efficiency would be (100x42*76-^-5,882 = ) 0*7 per cent., a result 
which was sufficiently absurd to prove that losses* due to time 
occupied in decking operations should not be debited against the 
plant in estimating its efficiency. 

• TraiM, Inst, M. E., 1906, vol. xxxii., page 291. 



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DISCUSSION — EFFECTS OF ACCELEEATION OX WINDING-TOEQUES. 57 

One of the chief features in this installation was that, with 
a maximum energy of 45 kilowatts delivered into the system, 
and that only over a short period of time, a peak-load of 104 
kilowatts* was obtained in the winder during the test. 

TTith reference to the useful efficiency in winding shale^ 
compared with the work done in the cylinders of the engine: 
the engine was situated about | mile from the mine at which 
the winding installation was situated. Diagrams were not taken 
at the time of the test, and, if they had been, they would have 
been useless, as power was delivered throughout a considerable 
area for other purposes, and thus there would always have been 
considerable doubt as to the proportions of power being taken 
by the different processes, more especially as the load was a 
variable one. It was perfectly safe, however, to assume an 
efficiency of 80 per cent, for the conversion from mechanical to 
electrical energy, including the loss in the cables; and, taking 
the useful efficiency or power delivered at the switchboard as 
46*7 per cent., then the total useful efficiency in lifting shale 
would be (46*7 x 80 -=-100 = ) 37-36 per cent. If this figure were 
taken, it should be pointed out in all fairness that the result was 
very much in favour of the winding-plant, as it comprized a 
high-class engine and boiler-installation, which, on calculation 
from tests, would give 1 kilowatt for a consumption of 4 pounds 
of coal. Allowing, say, 10 per cent, for the increase of energy 
necessary to deliver this unit at the switchboaru, this worked out 
at 4'4 pounds of coal per unit delivered at the winding-house. 
The total consumption per ton on the basis of the trials, without 
deduction for decking-time losses, was shown to be 0*866 unit 
per ton,t or (4*4x0*866 = ) 3*8 pounds of coal consumed per ton 
of shale raised. In compiling his previous estimate for com- 
parative purposes, it should be noted that he (Mr. Ness) took 
4 pounds of coal per unit,J but he had employed it per ton, as 
the difference was so trifling. A fuel-consumption of 4 pounds 
per kilowatt-hour, or 3 pounds per horsepower-hour, in mining 
operations was certainly a moderate figure compared with the 
figures given by their past-President (Dr. J. S. Dixon) in his 
** Presidential Address." The result of a test of all the engines 
at a modern well-equipped colliery showed that the average 

* TroM, Inst. M. E,, 1906, vol. xxxu., page 292, plate xiii., fig. 3. 

t Ibid., 1906, ToL xxxii., page 291. % Ibid., page 292. 



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58 DISCUSSION — ^TESTS OF A MINE-FAN. 

fuel-consumption was 8'21 pounds of coal per horsepower-hour, 
and in the case of two winding-engines 9*87 pounds of coal 
per horsepower-hour * 

The result of the test of the Tarbrax plant afforded a striking 
example of what could be effected by the concentration of power 
in, and transmission from, a central generating-station. 

The discussion was thereupon closed, and a hearty vote of 
thanks was awarded to Mr. Ness. 



DISCUSSION OF MR. JOHN B. THOMSON'S PAPER ON 
'TESTS OF A MINE-FAN."t 
Mr. Thomas Tukneb (Kilmarnock) wrote that the particular 
Gapell fan was built for a duty of 50,000 cubic feet of air per 
minute at a water-guage of 2 inches, on the usual condition, 
namely that the mine would yield that quantity at that gauge : 
the speed of the fan to be about 230 revolutions per minute, and 
the efficiency of the combined fan and engine approaching, say, 
70 per cent. Tests made by the owners showed 60,000 to 64jO00 
cubic feet per minute passing through the drift, at a water-gauge 
of 2 inches to 2^ inches, and the makers were not, therefore, 
required to perform any tests. Subsequent tests carried out in 
the fan-drift showed roughly 20 per cent, more duty than wa« 
shown down the pit; but, even when that 20 per cent, waa 
deducted from the above-given figures, the fan was evidently 
right for its work. He (Mr. Turner) did not expect quite so 
much as 86 or 87 per cent, of duty out of the installation, and 
he thought that the high figures were due to the testers 
not finding out all the negative or reverse currents of 
the eddies. To get these more accurately it might be neces- 
sary to divide the drift into 18 or -36, instead of 9 spaces. Anemo- 
meter-readings, however, should, if possible, be taken at a place 
where there were no eddies, that was to say, at a place where 
there was a steady flow of air in one direction over the whole 
area measured. In this respect^ the measurements down the pit 
were better than those in the drift, the latter being too short 
to allow the air to become steadied down to a regular flow in one 
• Trans. Inttt. M, E., 1902, vol. xxiii., page 373. 
t Ibid,, 1906, vol. xxxii., page 296. 



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DISCUSSION — TESTS OF A MINE-FAN. 69 

direction only in its length. The measurements down the pit 
might, however, not include all the air that passed through the 
fan. He asked whether there was a possibility of air or gases 
being drawn from the unworked seams at the bottom of the 
upcast shaft. 

Mr. H. D. D. Babman (Glasgow) considered that it would be 
difBcult to make accurate tests of this fan, as it must be admitted 
that Mr. Thomson had a very awkward shaft to work in. The 
tests would undoubtedly be influenced by the air having to turn 
round a sharp corner from the vertical shaft to the fan-drift. 
If Mr. Thomson could find time to erect shutters and to make 
tests witb the drift entirely closed, and then with apertures of 
4, 9, 16 and 25 square feet, he would thus get a characteristic 
curve which would show that his former tests with the full 
apertures were inaccurate. 

Prof. A. Bateau (Paris) wrote that the recorded experiments 
gave a combined result for the fan and engine nearly equal to 
the efficiency expected for an engine aJone. This surprising 
result could only be based upon errors in the methods of measure- 
ment; and, from the records of the results of the experiments, 
it was easy to recognize that the measurements of the volume of 
air and the measurements of the water-gauge both yielded exag- 
gerated figures. One could well, in this way, find an efficiency 
superior to unity, as had been done in other tests. One could 
not take too many precautions in making experiments on the effi- 
ciency of fans. The volume of air had been measured in the 
delivery-passage to the fan, immediately after an abrupt bend 
that conduced to throw the current of air to the upper part of 
the fan-drift, to such an extent that the cuiTent returned on itself 
in the lower part of the drift. In such conditions, the measure- 
ment of the volume by an anemometer would certainly yield 
results much greater than the reality. It was wellknown that 
anemometers always showed exaggerated results, and especially 
when the current in which they were placed was very irregular. 
The members might consult in this respect his (Prof. Bateau's) 
experimental work.* 

* ** Experimental Investigations upon the Theory of the Pitot Tube and the 
Woltmazm Mill," by Prof. A. Rateau, 'JraiiH, ImL M. E., 1899, vol. xvii., 
j>age 124. 



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60 DISCUSSION ^TESTS OF A MINE-FAN. 

The fourth experiment, made on November 14th, 1906, in 
which the air was measured at the pit-bottom and simultaneoufily 
near the fan, showed well the exaggerated volume : near the fan, 
the anemometers showed a delivery of 37*5 per cent, better than 
that at the bottom of the pit. Unquestionably, the volume near 
to the fan waa really greater than the delivery at the bottom of 
the pit, (1) because the atmospheric pressure waa rather less, and 
(2) there was probably a re-entrance of air at the interstices of 
the door that closed the upper part of the pit. But these causes 
of increased volume were certainly far from accounting for the 
37*5 per cent, shown by the anemometers. 

Regarding the water-gauge, it had been mentioned that this 
was measured in the fan-drift at the point where the current of 
air had a very high velocity, attaining and even exceeding 4,000 
feet per minute. This measurement had probably been made 
with a straight tube, whereas it should have been made with a 
Pitot tube, turned towards the current. In the measurement 
with the straight tube, account had not been taken of the energy 
(due to the actual velocity) that the cuiTent of air possessed in 
the passage, energy which assisted the fan. A velocity of 4,000 
feet per minute was equal to a supplementary water-gauge of 1 
inch ; and this was enormous when compared with the measured 
water-gauge of 2J inches. 

Besides the effect of the velocity of the air-current, it must be 
remembered also that the measurement by a straight tube indi* 
cated a figure less than that w^hich corresponded to the static 
pressure at the point of observation. For these reasons, it was 
probable that the pressure measured was about 40 per cent, 
higher than the true water-gauge. Consequently, he (Prof. 
Bateau) was of opinion that the tests had been made in a 
manner which did not allow of an exact measurement of the 
efficiency of this fan. In order to obtain more exact result s> 
it would be necessary to measure the volume in a drift, where 
the air-current was regular in all sections of the drift, and to 
measure the water-gauge in the drift in front of the fan at a 
point where the current had not a high velocity, and a correction 
corresponding to the velocity should be applied, a correction that 
was recorded when the measurement was made with a Pitot tube. 

Mr. T. Lindsay Galloway (Glasgow) said that he did not 
think that a test could be considered sufficiently conclusive when 



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DISCUSSION — ^TESTS OF A MINE-FAN. 61 

there was a difference of 30 per cent, in two measurements of 
the Tolume. He asked . whether the anemometers had been 
tested at high velocities, such as 60 feet per second. He did not 
know whether any better method, than that in operation in the 
mine, had been devised for producing high velocities. Perhaps 
some member could enlighten him on tnat point. He suggested 
as a subject for enquiry whether reliance could be placed on 
anemometers at high velocities, and what means were adopted 
for testing them. In any case, a reliable instrument wouia 
probably not give correct indications in an unsteady current, full 
of eddies, such as were produced in a short fan-drift. 

Mr. T. H. MoTTRAM (Glasgow) asked why the anemometei-s 
registered a greater velocity in the fan-drift than was due 
to the quantity of air actually passing. He would like to 
know whether the fan-drift, in which the air was measured, was 
level, if the fan was directly in the centre, and how near to the 
fan Mr. Thomson's measurements were taken. He noticed that 
the highest velocities were got at the top of the drift, and the 
negative ones at the bottom. This indicated that the main 
portion of the air-current was passing from the bottom of the 
drift at the shaft to the top of the drift at the fan. He would 
also like to know whether the high velocities referred to were 
still maintained at the top of the drift when the false floor of 
wood and brattice-cloth was in use. 'WTien an open light was 
held well to the side of an air-current passing through an air- 
regulator it became unsteady, and in some cases indicated a kind 
of whirl ; and, if this experiment could be applied to the air in a 
fan-drift, a similar result would probably be obtained, as the 
rebound and meeting of the currents at an angle would produce 
a whirl in the air in close proximity to the fan. He imagined, 
where the area of a fan-drift was considerably larger than the 
area of the ear of the fan, that the whirl would be intensifieil — the 
air to some extent moving round a centre, and consequently an 
anemometer would record misleading results. Mr. Thomson had 
referred to the vena contracta, or, as it is sometimes termed, the 
co-efficient of contraction of the area of a jet escaping from 
an orifice. The vena contracta is generally reckoned at 0'G5 times 
the area of the opening in a thin plate, but this may vary accord- 
ing to the construction of the fan. The application of this co- 



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62 DISCUSSION — ^TBSTS OF A MINE-FAN. 

eflBcient to a quantity of 58,000 cubic feet would yield about 
43,000 cubic feet, approaching the actual quantity passing- 
through the drift in the Ell coal-seam. At the same time, that 
application must not be considered as a reliable method of arriv- 
ing at the quantity of air actually passing. A simple experiment 
would show how unreliable measurements of air might be, when 
taken in close proximity to a fan. For instance, small pieces 
of paper, discharged into the current under some conditions, 
would indicate a whirl in the air. He had seen, while most of 
the pieces of paper made direct for the fan, that others whirled 
round and round before entering it. There could, he thought, 
be no doubt about the matter, and he agreed with Mr. Thomson 
that, in testing a fan for its mechanical efficiency, the measure- 
ments of the quantity of air should not be taken in the fan-drift 
— at any rate not in a drift so short as the one in which his 
experiments were taken. 

Mr. Sam Mavor (Glasgow) said that the observations of 
wind-pressure made by the engineers of the Forth Bridge, extend- 
ing over a period of seven years, elicited some points of interest 
in relation to the behaviour of air-currents. Wind-gauges of 
different sizes were used, varying from 1 or 2 square feet, to 300 
square feet in area, and it was found, during wind-storms, that 
the gauges of small area registered much higher pressures than 
the mean pressures on those of large area. The tests showed, 
even with gauges placed in the open atmosphere, high and free 
from disturbing environment, that the pressure on the surface 
(of a gauge with an area of 300 square feet) differed at different 
parts of the surface, and that the points of highest pressure 
changed from moment to moment, with a relatively small varia- 
tion of the total mean pressure. The occurrence of such differ- 
ences in the open atmosphere indicated the probability that 
similar fluctuations would occur in the roadways of a mine, and 
that they would be emphasized by the proximity and irregular- 
ity of the walls, floor and roof. 

Mr. J. M. Eonaldson (Glasgow) said that he found by experi- 
ence, many years ago, that the more slowly the air was travelling 
the more likely was it that he would secure accurate readings 
from the anemometer. He found that he could never really make 
a proper test when the air was moving at a great velocity in the 



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DISCUSSION — TESTS OF A MINE-FAX. 68 

fan-drift. He always preferred to take readings of the anemo- 
meter of the various splits of air belowground, as a proper index 
of the amount of air passing through the mine, in preference to 
taking a reading in the fan-drift where the air was probably 
travelling at a great velocity, and the whirls were apt to discon- 
cert the reading of the anemometer. In dealing with whirling 
currents, it was most difficult for any anemometer to register 
correctly the exact average velocity of the air. Therefore, lie 
thought that experiments should only be attempted under circum- 
stances where the air was not travelling at too high a velocity, and 
in a straight part of the airway where the area did not greatly vary. 

Mr. R. W. DnoN (Glasgow) said that recently he had had an 
experience similar to that recorded by Mr. Thomson, although 
he had not found time to go into the details in the same scientific 
way as that gentleman had done. The anemometer indicated 
about 60,000 cubic feet of air per minute in the fan-drift, but 
the actual quantity of air circulating underground was only 
about 40,000 cubic feet per minute. In his own mind, he was 
satisfied that the actual quantity was 40,000 cubic feet. The 
reading of the anemometer in the fan-drift, in his case, had been 
probably effected in the same way as in Mr. Thomson's tests. 

Mr. James Black (Airdrie) said that Mr. Thomson was 
perfectly right in regard to the method that he had adopted for 
calculating the efficiency of the fan. The work done on the 
negative currents was not the same as the work done on the 
positive currents, because, comparatively speaking, no work was 
done on the negative currents, and they were not circulated 
against the resistance of the mine like the positive currents. 
Mr. Thomson seemed to have been mystified at obtaining such 
widely different results; and if he had obtained the same 
efficiency in his series of experiments, he (Mr. Black) would have 
been just as much surprised' as Mr. Thomson had been. The 
members should consider the fact that the ear. of the fan was 
only 18 feet from the edge of the shaft, and the air passed round 
a right-angled turn, setting up cross currents ; and under such 
conditions, he was not surprised that the anemometer failed to 
record correct measurements, but indicated the velocity of the 
oblique currents. Mr. Thomson's results showed that negative 
currents flowed upon the floor of the fan-drift, and that the 



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64 DISCUSSION — TESTS OF A MINE-FAN. 

highest velocities existed near the roof. The highest velocity 
could have been measured in the centre of the fan-drift, if 
the velocity of the air-current, over the entire sectional area, 
had been at right angles to the cross-section of the airway. 
In his opinion, it was simply the length of the fan-drift that 
determined the extent to which the measurements of the velocity 
might be affected by cross currents. If the fan-drift had been 
sufficiently long to give the air-current time to get into its 
normal course, then it would have made no difference whether 
the air was measured in the fan-drift or at the pit-bottom, so 
far as accuracy of measurement at the respective points was 
concerned. A simple example of the effects of cross currents 
could be seen in any fast^running stream of water, where it made 
a right-angled bend; and negative currents could also be 
observed in many of such cases. 

He (Mr. Black) did not agree with the mode adopted by 
Mr. Thomson when measuring the ventilating-current. The 
nine spaces, into which the fan-drift was divided, had an average 
area of about 4 square feet, and consequently were much too 
large. The area of each space should have been restricted to 
about 2 square feet, in order that more accurate results might 
be obtained. He also objected to the method of fixing 
the anemometers on shelves, placed across the fan-drift, as the 
air, in passing through the divisions formed by the shelves, 
was affected in the same way as air was affected in passing 
through a regulator. The shelves had always a tendency, 
depending upon their thickness and width, to produce cross 
currents; and he considered that more accurate results could 
have been obtained by using fine wires to form the divisions, 
and by moving the anemometer slowly over the area of each. 
The instrument should be fixed to the end of a suitable stick, 
and held on one side and in front of the operator. He (Mr. 
Black) had proved, to his own satisfaction, that an obstruction 
placed in an airway would certainly divert the air-current and 
cause it to move obliquely; and these cross currents assuredly 
would cause the anemometer to indicate an erroneous velocity. 

The discussion was adjourned. 



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HEABING BY LONGWALL MACHINES. 65 



HEADING BY LONGWALL MACHINES. 



By SAM MAYOR. 



IntrodvMion. 

The problems associated with the driving' of headings are 
many, but the branch of the subject to be dealt with in this paper 
relates only to the advancing of working-places of sufficient width 
to permit of the stowage of the material ripped from two or more 
roadways, and in seams under, say, 4 feet thick. The method 
advocated has no reference to stoop-and-room working, nor 
to other cases where the mining conditions compel close places. 

The purposes for which it may be necessary to drive advance- 
workings into a coal-field may be roughly classified as follows : — 
(1) Winning out working-faces; (2) exploration to prove the 
field; and (3) advancing to a boundary for retreating longwall 
working. 

The driving of a heading is not in itself an end, but is merely 
proliminary or preparatory to operations on a more extended 
scale, and therefore it is usually of importance that the work 
should be expeditiously carried out. A frequent consequejQce of 
the necessity for rapid advance is the sacrifice of economy in the 
conduct of this operation. An endeavour will be made to show 
that the advent of powerful machines to the coal-face has so 
altered the possibilities that economy may be allied to rapidity 
of advance. 

Types of Heading Machines, 

The high cost and slow advance of headings driven by hand- 
labour, and the necessity for selecting the best miners for this 
work, have stimulated a demand for mechanical aid, and response 
has been made by machines of three types, namely : — (1) Rotary 
heading machines; (2) channelling machines; and (3) chain- 
breast machines. To this list the longwall bar-type of coal- 
cutter may now be added. 

TOL. XXX1II.-190«.M07. 5 



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HEADING BY LONGWALL MACHINES. 



Rotary Heading Machines, — ^Rotary heading machines have a 
considerable vogue in the Midland counties for driving roads in 
thick coal-seams, but the lype does not appear to be applicable 
to the conditions prevailing in this district, and does not require 
detailed reference here. 

Channelling Machines, — Channelling machines may be 
described as mechanically operated and hand-controlled portable 
tools, and they may be used with advantage under conditions 
usually associated with hand-labour. Their sphere is essentially 
in close places and steep seams, where portability and conveni- 
ence of handling are primary considerations, and where the 
material to be holed is exceptionally hard. Under ordinary 

conditions the actual rate 
of undercutting is rela- 
tively slow ; and, in places 
exceeding 10 or 12 feet in 
width, machines of greater 
weight and power rapidly 
assert their superiority 
over the channelling type. 
When channelling ma- 
chines are used, as they 
sometimes are, for making 
a series of semicircular 
cuts along a face which 
cannot be described as nar- 
row, the effective range 
of the machine, in each 
position, is reduced by the 
necessity of overlapping, in order to avoid leaving triangular 
pieces uncut between the semicircular sweeps of the tool. This 
type of machine is less effective in deep than in relatively shallow 
undercutting. The accompanying curve (fig. 1) has been diuwn 
from data given in the Report of the Committee of the North of 
England Institute of Mining and Mechanical Engineers upon 
Mechanical Coal-cutting,* This shows the relation of the depth 
of cut to the number of square feet cut per hour by the machine. 
The writer is not aware of any satisfactory solution of the 
• Part II.— Heading Machines, page 43. 




20 40 60 80 

DEPTH OF cur IN JNCH ES 

Fig. 1.— Curve showing the Relation 
OP THE Depth of the Undebcut to 
the wobk done by a channelling 
Machine. 



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HEADING BY LONGWALL MACHINES. 67 

problem of operating the percussive type of machine directly by 
electricity, and the necessity of providing compressed air is 
frequently a bar to the adoption of this type. 

Chain-breast Machines, — Chain-breast machines are most use- 
fully employed for driving close places in thick seajns, or in 
stoop-and-room working, where the roof is good, the holing not 
very hard, the seamB not steep, and where the rooms are wide ; 
the best performance, relatively to other machines and subject 
to the above limitations, is probably attained in places which 
are 24 to 36 feet wide. The effective width of the cut made 
by the chain-breast machine, in each position, is reduced by 
about 6 inches by the necessity of overlapping in order to avoid 
the leaving of triangular pieces at the back of the cut. 

Longwall Bar Cod-cutters. — The longwall bar coal-cutter, the 
use of which the writer advocates for heading, is too well known 
in this district to require description here. The standard Pick- 
quick machine of medium or small size, with a cutter-bar of 
requisite length, is suitable, without further modification, to the 
advance of places 90 feet wide. In connection with the applica- 
tion of bar machines to heading work, it is permissible to 
emphasize the distinction between this machine and the bar 
type of heading machine which has been used in America. The 
latter is of the breast type in which the bar, carried by a rect- 
angular frame, is advanced into the cut in a direction at right 
angles to the face similarly to the chain-breast machine. The 
feature of the longwall bar machine, especially adapting it for 
heading work, is the aiTangement which enables it to cut-in at 
one end of the face and to cut-out at the other — thus avoiding 
the necessity for stable-holes. 

Performance of Machines. 

There is wide divergence between the best performance of 
any machine under test or specially prepared conditions and in 
the hands of a skilled operator, as compared with the average 
performance of similar machines, subjected to varying and often 
adverse conditions, and to unskilled or unintelligent manipula- 
tion. This is especially true of all machines of portable type, 
in which the personal factor of the operator is so important, 



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68 



HEADING BY LONGWALL MACHINES. 



and to this class heading machines belong. The Report* 
already referred to, contains data relating to the performance 
of channelling and chain-breast machines which illustrate the 
point. The amount and character of the details of the various 
examples cited in the Report are not identical, but the writer has 
endeavoured to compile from them the averages relating to about 
thirty machines (Table I.). The incompleteness of the information 



Table I.— Average Results of Undktututting ik Headings bi 


' Channelliko, 


Chain -BREAST and Long wall Bar Machines. 




Type of Machine. 


Channelling. 


Chain-breast. 


Bar. 




A* 


B* 


C 


Thickness of seam 


3 ft. 10 in. 


4 ft. in. 


3 ft. in. 


Width of place 


12 ft. 


30 ft. 


90 ft. 


Height of roadway 


6 ft. 6 in. 


6 ft. 6 in. 


6 ft. 6 in. 


Depth of underctit 


4 ft. 6 in. 


5 ft. 8 in. 


6 ft. 


Rate of advance per day 


4 ft. 6 in. 


5 ft. 8 in. 


6 ft. 


Increase in rate of advance com- 








pared with hand.work 


84per oent. 


105 per cent. 


. 


Area undercut per hour 


14-6 sq. ft. 


32 sq. ft. 


67 sq. ft. 


Area undercut per shift of 8 hours 


13 sq. yds. 


29 sq. yds. 


60 sq. yds. 


Cost of machine-labour, per shift 


15s. 


17s: 


£1 L 


Labour-saving, as compared with 








hand-work 


31 -6 per cent. 


46 per cent. 

E 




Interest, depreciation and repairs 


D 


P 


per shift 


28. 


6s. 


6s. 


Power-supply, per shift 


2s. 2d. 


2s. 5d. 


38. 9d. 


Do. per square yard ... 


2d. 


Id. 


id. 


Total cost of undercutting, in- 








cluding labour, per shift 


19s. 2d. 


£1 5s. 5d. 


£1 138. 9d. 


Total cost per square yard 


Is. 8-4d. 


Is. l-2d. 


Os. 6'75d. 


Labour cost per square yard, by 








hand 


Is. 11 od. 


Is. 4-4d. 


••• 


Net saving in cost, eflfected by 








machine ... 


31d. 


3-2d. 





* These columns contain the average results of the performances detailed in 
the lieport of the Committee of the North of England histitule of Mining and 
Mechanical Engineers upon MechaniccU Goal-cutting, 1905. 

available in respect of some of the examples precludes exactness 
from this table, but it may be accepted as approximately correct. 
The upper columns, A and B, give the averages of the perform- 
ances detailed in the Report. The lower columns, D and E, are 
deduced from the upper columns, with the addition of the items 
" interest, etc.," and " power-supply : " items which are frequently 
omitted from comparisons of machine with hand-costs. Columns 
C and F relate to the performance of a deep undercutting Pick- 
quick bar coal-cutter, of the standard longwall type, operating 
• Part II.— Heading Machines, page 43. 



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HEADING BY LONGWALL MACHINES. 69 

on a face 90 feet wide. The table simply g-ives a comparison of 
the amount and cost of undercutting by the respective machines. 
It will be seen from Table I. that the averag^e saving eflEected 
in the cost of undercutting by channelling and by chain-breast 
machines was, under the respective conditions of operating, 
approximately the same, the amount of saving being slightly 
over 3d. per square yard. The money directly saved by under- 
cutting with these machines, instead of by hand, in a heading 9 
feet wide advanced 100 yards, would therefore appear to be only 
about £4, and the inducement to use machines must be found 
in the accelerated rate of advance, rather than in reduced cost. 

It may be objected that it is unfair to compare a single 
example of the bar machine with the averages of a number of 
the other two types, but a number of examples of the use of 
the bar machine in headings 90 feet wide is not yet available. 
The case given, however, refers to the driving of a very wet dip 
working, in which the conditions were extremely unfavourable 
to any type of machine, and would have been still more so to 
hand-working. The only other example of which the writer 
hsA data is much more favourable to the bar machine, owing to 
the place, which was undercut 6 feet deep by a medium-sized 
machine, being considerably wider. The wider the place, up to 
the limit of capacity of the machine, the less will be the cost 
of undercutting by the bar machine. 

It is to be noted that the average performance of the channel- 
ling machine is equivalent to undercutting two places, also that 
the chain-breast machine, if advancing for heading purposes, 
a place of sufficient width to permit of forming two roads, 
would give better results than are shown in Table I. 
Of the chain-breast machines referred to in the above cited 
Report as being at work in this country, the one that gave the 
best results operated in a winning place, 45 feet wide, and the 
average time required to undercut this place to a depth of 5i 
feet was 8 hours. 

Method of Working, 

The suggestion, which is the purpose of this paper, is not 
revolutionary in character. It accepts an established and widely 
practised system of advancing headings by hand-labour, and 
merely advocates the use of the deep cutting-bar machine under 



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70 



HEADING BY LONGWALL MACHINES. 



existing mining conditions. It is especially applicable to thin 
seams, in which it is necessary to advance a place of considerable 
width in order to provide space in the goaf for the stowage of 
material ripped from the roadways. Fig. 2 is intended to repre- 
sent a heading by which a pair of roads are advanced ; the system 
has many variants, but the example shown, relating to a seam 
2^ feet thick, will serve for its general illustration. Under the 
conditions indicated by fig. 2, the whole space, 90 feet wide 
(except the roctdways, a, 12 feet wide, and, 6, 8 feet wide, and 
the two cundies, c, 5 feet wide), is required to contain the ripped 

material. In 
seams thinner 
than 2J feet, a 
place wider than 
90 feet (assum- 
ing the road- 
ways to be of the 
stated dimen- 
sions) would be 
required to con- 
tain the ripped 
material. In 
thicker seams, a 
less width would 
be sufficient to 
provide for 
stowage, but it 
is recommended, 
where the bar 
machine is used, 
that the mini- 
mum width of 
place should be 
90 feet, a cundie 




Fig. 2.— Plan of a Heading, 90 Febt wide, 

WITH Two Roads. 

ScALB, 32 Feet to 1 Inch. 



being left in the centre of the waste between the road-packwalls. 
No gain in rate of progress would accrue from forming a narrower 
place, but the output would be reduced and the costs increased. 

As indicated by fig. 2, the bar cuts into the coal at the 
position, A. When the machine reaches the second road-end, C, 
it is turned there, and cuts, with the bar leading, to the end of 



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HEADING BY LONGWALL MACHINES. 71 

the face, D, where the bar is swept through a quarter-circle thus 
cutting-out. On the return journey, the process is repeated, the 
machine being turned at the second road-end, B. On a nearly 
leyel floor and under a good roof, the machine can be turned in 
half-an-hour. When driving to the dip, one end of the face 
should be kept slightly in advance of the other, so that water 
will flow to this end, where it can be dealt with by a pump. 

When bar-machines are used in the manner described, the 
rate of advance of the heading is limited only by the time 
required to fill the coal. Experience of the method has shown 
that a place, 90 feet wide, can be advanced, by a machine under- 
cutting 6 feet deep, at the rate of 36 feet per week. Regular 
advance at this rate requires the application of vigorous super- 
vision to ensure the stripping of the face. The wider the head- 
ing, the more difiicult it is to apply and maintain the requisite 
pressure; and it is suggested, where the coal is hand-filled and 
where quick advance is a primary consideration, that a length 
of 90 feet of face should not be much exceeded. There is loss 
instead of gain in attempting too much; failure to strip the 
face in one day means the sacrifice of one day's forward progress, 
and the deeper the cut the greater will be the loss. If, how- 
ever, arrangements can be made for filling the coal with 
certainty, economy will be effected by increasing the width of 
the heading up to the limit of the capacity of the machine to 
cut regularly across it in one shift. The time required to place 
the machine in position preparatory to beginning to cut, and 
the time required to turn the machine, are constant for any 
length of face. With a face longer than 90 feet^ therefore, a 
greater proportion of the shift will be .spent in productive work. 

The depth of the undercut in a seam over 2 feet thick may, 
so far as the machine is concerned, be anything up to 6 feet. 
The medium-sized Pick-quick coal-cutter, which on a long- 
wall face normally cuts between 3 and 4 feet deep in moderate 
fire-clay or coal-holing at the rate of 18 inches per minute, will 
undercut 6 feet deep at the rate of about 12 inches per minute. 
If rapidity of advance were not a primary aim, an undercut 4^ 
feet deep would probably be considered sufficient and the small 
size Pick-quick, which normally undercuts 3 to 3J feet deep, and 
which with skids weighs only 28 cwts., is well suited for this 
duty. In hard-holing the rate of progress along the face might 



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72 HEADING BY LONG WALL MACHINES. 

be half that attained on a longwall with a shallower cut, but the 
distance to be traversed is only one-third or one-fourth of a long- 
wall face, and there is ample time to cut through and to turn 
the machine in a shift. 

If any exceptional conditions render it impossible in the 
time available to fill the coal when undercut to the depth indi- 
cated, or if other considerations dictate a shallower undercut, 
this can readily be adjusted by the use of a shorter cutter-bar. 

A medium-sized machine was recently set to work with a 6 
feet bar, on a face 72 feet long between a rib-side and a roadway 
at an angle with it. The face was advanced 6 feet each cutting 
shift, until it reached 240 feet in length. Owing to a scarcity 
of men it was found impossible to strip the face each day, and 
a shorter bar was inserted in order to give an undercut 4^ feet 
deep, and to reduce Uie yield of coal within the capacity of the 
fillers. The full advantage of deep undercutting was not in 
this instance realized, but its value and possibilities were amply 
demonstrated. 

The time required to place the maehine in position, to cut 
across a face, 90 feet wide, and to turn the machine, is, under 
moderately favourable conditions, about 4 hours. It should, 
therefore, be possible, if it were important to do so, to undercut 
4^ feet deep in a seam about 2^ feet thick and to strip it in 12 
hours. Filling could commence soon after the machine started 
to cut, and the machine-men, on the completion of the cut, could 
assist in filling the coal. This arrangement if the work were 
contracted appears practicable. The rate of advance in such 
a case would be 9 feet per day. 

In ordinary longwall working, the rate of advance (unless 
the holing is exceptionally hard) depends less upon the under- 
cutting than upon the rapid stripping of the face. The same 
truth applies with greater force to a heading worked 
by a longwall machine. With well-organized hand-filling, 
machine cutting, as advocated for headings, had in prac- 
tice proved to be much more rapid and economical than hand- 
holing. But the possibilities of economy in driving headings 
are not exhausted by machine-holing. The mechanical conveyor, 
as an adjunct to the coal-cutter in a heading 135 feet or 150 feet 
wide, would greatly augment the effectiveness of the method 
proposed. Indeed, it will only be by the co-operation of the con- 
veyor that the full advantage of the method will be realized. 



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HEADING BY LONGVVALL MACHINES. 



73 



In view of the larger output which would be yielded from 
advance workings by the method proposed, reference may appro- 
priately be made to auxiliary haulaiges — appliances which might 
with profit be much more generally adopted. This district com- 
pares unfavourably with some others in regard to the use of 
electrically-driven, portable or semi-portable haulages for 
auxiliary purposes. It is to be remembered that wherever 












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V . ^ * r J, * 






"^ 






:* ^ , J * * • ' ' *■ - 










nirbc^j>J<- j%j*LJntfV*.> 



^ 



I 



an electric coal-cutter works at night, a cable is in the daytime 
available to supply electric power, and this could often be used 
with advantage in connection with auxiliary haulage. 

It would appear that every advantage attending the use of 
machines on longwall faces would apply in greater measure to 
the use of the bar machine for advancing headings, and these in 



VOL. XXXIlI.-1906.1«r?, 



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74 HEADING BY LONGWALL MACHINES. 

addition to the special desideratum of rapidity of progress. The 
driving of headings by hand costs a considerably higher rat« 
per ton, especially in dip workings, than hand-labour in the same 
seam on longwall faces. Yet in the example already referred to, 
the costs of driving a very wet dip working, 90 feet wide, by a 
bar machine, closely corresponded to the costs of longwall work- 
ing by machines in the same seam. Most colliery managers in 
the district have experience of machines on longwall faces, they 
know why they are using them in rapidly increasing numbers; 
they also know the amount of direct saving in costs, and the 
incidental advantages and economies effected by these machines. 
Members are, therefore, themselves in the best position to esti- 
mate the saving to be gained by the application of machines in 
the manner suggested, to the conditions with which they indi- 
vidually have to deal, and to make their own valuation of the 
benefits to be realized. 

. For winning-out, the face might suitably be 136 feet wide ; a 
haulage-road, a, being formed in the centre (12 feet wide) ; side 
roads, b and b (8 feet wide), on each side; two cundies, c (6 feet 
wide) ; and cross-gates, d and e, as indicated in a general way by 
fig. 3. As the winning heading advances, longwall-machine 
faces are thus prepared on either side, and as these longwall 
faces when worked recede from the haulage-road, slant-roads 
may be formed to cut off the cross-gates. 

Advantages, 
The special advantages resulting from the use of longwall bar 
coal-cutters in heading work may be summarized as follows : — 

(1) The avoidance of hand-holing at the face when holing is most 
difficult, that is, before the roof-pressure comes on the coal-face. 

(2) A substantial output in good condition is obtained from the 
heading at low cost. (3) Sapidity of advance is secured without 
any sacrifice of economy. (4) Ample stowage-room for the 
ripped material encourages the formation of haulage-roads of 
liberal width. (5) For exploration-purposes, the wide heading 
reveals more than a narrow one. (6) Heading by a bar machine 
requires the same class of labour as an ordinary longwall face, 
whereas for heading by hand skilled men must be picked, and 
these are withdrawn from more productive work with a conse- 
quent reduction of output. Assuming, as possible, a rate of 



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HEADING. BY LONGWAIX MACHINES. 76 

progress by hand-working equal to that made by the machine, 
double the number of men, skilled men, would be required. 
{7) The machine used for winning-out only requires a change 
of cutter-bar to adapt it for longwall working. 

The added advantages gained by machines may extend the 
system represented by figs. 2 and 3, or some modification of it, 
into seams the thickness of which has hitherto excluded it. 
Where thick seams are worked on the panel system, the deep 
undercutting-bar, used as described, would yield excellent 
results. 

Limitations. 

Steepness of the seam, within the usual limitations in this 
country, is not a bar to success. The method advocated can be 
applied in seams inclined 1 in 3^, and faces can be advanced 
straight to the dip, straight to the rise, or at a right angle to the 
line of dip. 

The nature of the roof may prohibit an undercut so deep as 
6 feet. In such a case, the bar can be shortened so as to meet 
ihe conditions. It should be remembered that, with an under- 
cut of 4 feet or more, the machine is under a new roof for each 
cut. 

The system of heading now under review is, of course, not 
universally applicable, and the limitations which apply to the 
system when operated by hand would, for the most part, be valid 
as regards machine-working, but there are few cases in which it 
could be adopted and worked by hand where it could not be 
worked to greater advantage by the bar machine. 

The limit of thickness of seam to which the system could be 
usefully applied must depend upon local conditions. It is 
probably about 4J feet, but other limitations may emerge in the 
discussion. 

It is probable that increasing experience in the application of 
longwall machines and fuller acquaintance with their capabilities 
will tend to a progressive diminution of narrow work. In plans 
of new workings its complete abolition has already been fore- 
cast by mining engineers of wide experience in the handling of 
machines. 



TOL. XZZni.~lMM-lM7. 



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76 TRANSACTIONS. 



THE NORTH STAFFORDSHIRE INSTITUTE OF MINING 
AND MECHANICAL ENGINEERS. 



GENERAL MEETING, 

Held at the North Stafford Hotel, Stoke- upon -Trent, 

February 4th, 1907. 



Mr. JOHN NEWTON, President, in the Chair. 



The minutes of the la«t General Meeting were read and 
confirmed. 



The following gentlemen, having been previously nominated, 
were elected : — 

Member— 
Mr. H. Johnstone, H.M. Inspector of Mines, Stafford. 

Associate— 
Mr. John Bentley, Grackley Colliery, Chesterton. 



DEATH OF MR. W. H. DAVIES. 

The President (Mr. John Newton) said that, since their last 
meeting, they had sustained a loss in the death of one of their 
most esteemed and respected members. He referred to the late 
Mr. W. H. Davies, general manager of the Shelton Iron, Steel and 
Coal Company, Limited. The Council had decided to send a 
letter of condolence, but they felt that an expression of sympathy 
coming from the whole of the members of the Institute ought 
to be forwarded. Mr. Davies had been a member of the Institute 
since he came to the district, and he had gained the respect of 
everybody who knew him. Steel-making had been a difficult 
process in North Staffordshire, as everything had militated 
against its manufacture, particularly their inland position and 
the railway-difficulties with which they had to contend. Mr. 



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TRANSACTIONS. 77 

Da vies had taken up the work of lessening those difficulties, and if 
he had lived something would have been done to relieve the pres- 
sure that crippled the manufacture of steel by facilitating its 
export out of the district. He moved that a letter of condolence 
be sent from the Institute to the widow and family, expressing its 
profound regret at the irreparable loss that they had sustained, and 
he would ask the members to rise in their places, so as to show their 
feeling in this matter. 

The resolution was carried by the members standing up in 
silence. 



PRIZES. 
The President (Mr. John Newton) presented prizes to the 
writers of the following papers : — 

" Notes on the Feed-water of Colliery-boileni." By Mr. A. E. Cooke. 
"A Gob-lire in the Ten-feet Seam, North StaflFordahire." By Mr. W. G. 
Peasegood 



Mr. St. V. Champion Jones read the following paper on 
'* A Gob-fire in a Shropshire Mine " : — 



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78 A GOB-FIBE IN A SHBOPSHIBE MINE. 



A GOB-FIRE IN A SHROPSHIRE MINE. 



Bt ST. V. CHAMPION JONES. 



This gob-fire occurred about the middle of 1906, at the Free- 
hold colliery, belonging- to the Lilleshall Company, Limited. 

Before dealing directly with the fire, it will be desirable to give 
a brief outline of the geological disturbances to which the strata 
at this colliery have been subjected, and a few particulars with 
regard to the practical working. 

The general average dip of the measures, throughout this 
district, is 1 in 12 in a north-easterly direction, and it is fairly 
evenly maintained until within about 150 feet from the shafts of 
the Frfeehold colliery. There is then a gradual lessening in the 
rate of dip until the strata reach the horizontal position ; and 
thence they rise very rapidly northward until a maximum 
gradient of 45 degrees is reached. The gob-fire broke out in the 
steep workings of the Double coal-seam (fig. 1, plate i.). This 
sudden upheaval of the measures is in all probability due to the 
wellknown landmark known as Lilleshall hill, consisting of am 
eruptive igneous rock protruding about 200 feet above the sur- 
rounding surface. The outcrop of some of the coal-seams have 
been traced to within about | mile from the foot of this hill, and 
it is towards this outcrop that the present coal-faoe is advancing. 

The depth at the shafts to the Double coal-seam is 627 
feet; but, owing to the abnormal rise of the measures, the depth 
from the surface to the point where the fire occurred would not 
be more than 330 feet (fig. 2, plate i.). 

The following is a section of the Double coal-seam : — 

Ft. InB. Ft. Im. 

J?oo/; Rock 2 

COAL, with nodules ... 9 

Rock 2 

False rock ... 1 



Seam: COAL 
Floor : Dark shale 



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A GOB-Fnt£ IN A SHROPSHI&E MINE. 79 

The seam is worked by the longwall method, levels being 
driyen at about right angles to the dip, and jigs set off about 120 
feet apart. 

Heating, without stink, was first perceived on April 5th, 1906, 
at A (fig. 3, plate i.). The gob at this point had fallen to a con- 
siderable height, and as it was considered impracticable to attempt 
to dig it out, it was decided to seal it off by means of a 
brick-wall. A rock-building, a, was therefore built across the 
waste, and a brick-and-mortar wall, e, 14 inches thick, was built 
in front of it, from the coal-pillar on the left to the top of 
Powell's jig ; and it was continued down this jig, as it was found 
that carbon dioxide was making its way through the jig-side 
pack-wall. This wall was carried down the jig in sections, 12 
feet long, each section being built up-hill against the ventilating 
current. This method was adopted, as it was ascertained that^ 
when bricking downhill, the carbon dioxide found its way, along 
the back of the wall, to the bricklayers working at the end of it ; 
and this notwithstanding that 15,000 cubic feet of air per minute 
was passing down the jig. A space of 18 inches was left at the 
back of the wall, and this was filled with black sand, e, as the 
brick- wall was erected. 

Actual gob-stink was first noticed at B (fig. 3, plate i.), 
about 8 weeks after heating was perceived at A ; and a stopping 
was at once erected at this point between the coal-pillar and the 
cog. A brick-wall, c, 18 inches thick, was also carried up the side 
of this cog, and black sand, c, was rammed behind it. As an extra 
precaution, the wastes, C, D and E, were built off by means of dirt- 
and-sand stanks ; and the waste, E, was further sealed by means of 
a brick-and-mortar wall, e, 18 inches thick, a slight trace of gob- 
stink having been noticed at this point. 

While the brick-wall was being built down the side of Powell's 
jig, the heading was driven from F to G, and connected to Powell's 
jig, so that, if necessary, a barrier of sand, or other non-inflamm- 
able material, could be formed between the brick-wall, where 
heating was first perceived, and the coal-face. This, however, was 
not required, owing to subsequent developments, which will be 
explained later on. 

The work of building the walls was, of necessity, a very slow 
process, on account of the difficulty of getting the material, up 



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80 A GOB-FIKE IX A SHKOPSHIRE MINE. 

the jigs, to the place where it was required. The bricks, sand 
and mortar were conveyed up Wakeley's and Darlington's jigs 
against tubs of coal (the gradient in these jigs being about 45 
degrees), and carried along the face. 

The solid coal-pillar (figs. 1 and 3, plate i.), consisted of 
soft faulted coal, with numerous slips in it, and the seam was 
about 12 feet thick, that is, more than twice the normal thickness. 
The coal here was of so soft a nature that it could be ground to 
powder in the hand, with very little effort. This pillar had 
been left, as it was not considered safe to work the coal at that 
point owing to the exceptionally bad nature of the roof, and 
because there was not sufficient material for cogging purposes. 

On Saturday, June 2nd, 1906, the condition generally seemed 
to be much improved, and the brick-wall in Poweirs jig had 
reached a point about 30 feet from the underlying level. The 
thermometer, which was hung against the brick-wall about half- 
way down the jig, where the temperature was highest, showed 
that the temperature was decreasing. It had never been higher 
than 69° Fahr. ; but, at this time, it was only 67° ; and the place 
seemed to be cooling down. However, on the following Monday, 
June 4th, the fireman reported that a thin stream of smoke, 
about as thick as his arm, was making its way from the rise-side, 
H, of a dirt-stank, 6, in the level at the bottom of Powell's jig. 
Men were at once dispatched to the place with the object of trying 
to build a wall along the disused part of the level, to the coal- 
pillar, as had been originally intended, so as to seal the waste on 
all sides, and prevent the heating from extending to the gob on 
the lower side of the level. 

All went well until Wednesday evening, June 6th, the level 
having been cleaned up about 15 feet from the bottom of the 
jig, and a brick- wall partly put in on the top side. The under- 
manager and the writer, on arrival at the pit, were informed that 
the men working in the place had come out, stating that there 
had been a fall in the level where they were working, bringing 
live fire with it and a quantity of smoke; and that they were 
compelled lo beat a hasty retreat. The writer at once descended 
the pit, and as soon as he had passed through the two doors, R, 
into the return-airway, he perceived that it was charged with 
dense smoke, and it was only possible to see a few feet in 
advance. He therefore decided to try and reach the fire from the 



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A GOB-FUt£ IN A SHROPSHIBE MINE. 81 

intake-airway, and accordingly he travelled up Darlington's jig 
and along the face to PowelPs jig, down which he proceeded till 
he got to within a few feet of the bottom. At this point, further 
progress was arrested by white smoke, so thick that he could not 
see more than a foot in advance, and a lamp held in it was 
extinguished almost instanteously. The fire could be heard 
crackling a few feet away, and a faint red glow could just be seen 
through the smoke. He then returned up Powell's jig, and 
along the face to the top of Wakeley's jig, and parti}- lifted 
the brattice-sheet, 0, in order to take more fresh air down the 
jig. On returning down the jig and reaching the level below, 
he was surprised to find that it was practically free from smoke, 
and, looking along it, he could see the fire blazing at the far end. 
He then proceeded along the level to the bottom of Powell's jig 
and within a few feet of the fire. When this point was reached, 
it was seen that an unexpected change had occurred in the 
ventilation, as the smoke and fumes from the fire were ascending 
Powell's jig in large volumes. He, therefore, beat a hasty retreat 
into a current of fresh air, coming along the level, just beyond 
the bottom of Wakeley's jig. This point was reached just in 
time to escape the smoke which was rolling down Wakeley's 

jig- 
Under ordinary conditions, two splits of air united at the top 
of Powell's jig ; the one from the west ventilated the pack-level 
district, and the one from the east came from the Muxton- 
Bridge pits, about i a mile distant, which ceased to wind coal 
about a year ago. The united air-current travelled down Powell's 
jig and an abandoned jig, on to the main or new-opening level 
below. When the brattice-sheet, O, was lifted in Wakeley's jig, 
part of the ventilating current from the Muxton-Bridge district 
naturally short-circuited down the jig : this decreavsed the air- 
current in Powell's jig, and consequently the heated air from the 
fire waa able to form a motive column in this jig and so reverse 
the air-current. This was an instance (which was certainly 
unique in the writer's experience) of the ventilation going the 
longest way round, instead of taking the shortest, and, under 
ordinary circumstances, the easiest, direction ; and had the mine 
been anything but highly inclined, the writer is of opinion that 
this change would not have taken place. 

Matters were then looking very serious, and, after a somewhat 



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82 A GOB-FIKE IN A SHROPSHIRE MINE. 

lengthy discussion, the writer came to the conclusion that, at 
least, the whole of the new-opening district would have to be 
abandoned, by building stoppings and. sealing it off. But it could 
be recognized that even this would be no easy matter to accom- 
plish effectively, as the east side of the face was stripping some 
old workings, which had been abandoned about 4 years ago ; and 
the roadways and workings were still in a fairly open state, so 
that the only way of building satisfactory stoppings on this side 
was to go right back to the Muxton-Bridge pits and build them 
in the shaft-pillar. Brick-and-mortar stoppings were therefore 
built at J, K, L and M (fig. 1, plate i.). On the west side, it 
was decided to build a main stopping, N, in the new-opening 
level, and another, P, at the coal-face, up Darlington's jig- 
Stoppings, TJ atnd V, were also erected in the old headings on the 
east side of the Freehold pits. The main stopping, N, in the 
new-opening level consisted of two brick-and-mortar walls, each 
3 feet thick, 6 feet apart, built well into the sides, as the ground 
was much broken. Between these walls, two brick-walls, 9 inchea 
thick, were built at right angles and about 2 feet apart, so that 
the stopping could be completed, with the exception of a small 
hole about 2 feet square, which could be quickly closed as soon aa 
the other stoppings were completed. Black sand, from the 
foundry, was used for filling between the walls and was rammed 
solid with wooden rammers. The building of this stopping wa» 
carried out under considerable difiiculties, on account of its being 
in the return-airway from the fire ; and, although fresh air was 
taken in to the men by means of a range of air-pipes, it was found 
necessary to divide the men into three divisions, each division only 
being allowed to remain at the stopping for 3 minutes before 
being relieved by the next : 5 minutes was allowed at first, but 
this time was reduced to 3 minutes as some of the men com* 
plained of feeling bad, and showed signs of carbon-monoxide 
poisoning. 

The stopping, P, at the coal-face up Darlington's jig was built 
in the following manner: a dirt-and-sand building, d, 4 feet 
thick, was built across from the coal-face to the cog; and 3 feet 
distant from this, a brick-wall, e, 9 inches thick, was built, and 
the intervening space was filled with black sand, c. The stopping 
was built with a brick-wall, only 9 inches thick, owing to the 
difficulty of getting a sufficient supply of bricks and mortar up 



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A GOB-FIBE IX A SHBOPSHIKE MINE. 88 

the jigs. While this stopping was being built, a temporary stop- 
ping was erected at the bend in the heading, FG, and in the air- 
way, BF, between the brick-wall and the west side of the coal- 
pillar. These stoppings were made with slack-coal, the only 
material at hand. 

Previous to these stoppings being erected, smoke with carbon 
dioxide was backing along the coal -face towards the place where 
the permanent stopping was being built : consequently the situa- 
tion was much improved by the erection of these slack-coal 
stoppings. 

The main stopping, E, near the Muxton-Bridge pits, and the 
main stopping, N, in the new-opening level, were the last to be 
closed. It was arranged that they should be closed simultan- 
eously ; but, as a matter of fact, the Muxton-Bridge stopping was 
closed a few minutes before the other. 

The fire was, in the writer's opinion, due to the oxidation of 
coal, without the assistance of pyrites. Pyrites is met with occa- 
sionally embedded in the coal in the form of lumps, but it is not 
found in sufficient quantities to justify the opinion that the 
origin of the fire was, either partly or wholly, due to its pres- 
ence. The coal, at the point where the fire started, had the 
appearance of being highly carbonized, and looked as if it had, at 
some time or another, been subjected to great friction. It is not 
thought that such friction or pressure contributed to the fire 
in the present instance, except from the fact of the coal being 
crushed into small pieces and consequently rendering it more 
liable to oxidation. 

Similar belts of soft, sooty coal had occurred in other parts of 
this seam, and fires had been frequent ; but there had never been 
any signs of heating when the coal had been strong and in its 
normal condition. 

At the Granville colliery, about IJ miles distant, where the 
Double seam had been extensively worked, a fire had never 
been known to occur. 

The conditions prevailing at the present time are as follows : 
— The stopping, Jf, in the new-opening level has been 
strengthened by sand-and-brick walls, and has now a total thick- 
ness of 45 feet. A pipe, 2 inches in diameter, has been fitted 
through the stopping; and, on the valve being opened, carbon 



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84 DISCUSSION — A GOB-FIRE IN A SHROPSHIRE MINE. 

dioxide issues from it under slight pressure. A light is extin- 
guished in a few seconds when held at the end of the pipe. The 
temperature on the wall of this stopping is 81° Fahr., and this 
has been constant for some months. 

The stopping, P, at the coal-face of Darlington's jig has also 
been strengthened by filling the face from the stopping to the 
jig-side, with riddled slack-coal and sand, g. The temperature is 
62° Fahr. 

A roadway, S to T, has been driven in the gob of the Top 
coal-seam, about 18 feet above the Double seam (fig. 1, plate i.). 
This roadway provides an auxiliary airway, so that the roadways 
to the west of the coal-pillar could be closed, should the fire 
show signs of eating its way. into them. At the present time, 
there are no indications of the fire breaking through, and the 
writer hopes that it has been satisfactorily enclosed. 



Mr. F. H. Wynne said that the coal in the pillar was faulted, 
of a peculiar character, and a handful could be crushed to powder 
by simple pressure. He had taken samples of the soft and of 
the hard coal, and had hoped to have made experiments as to 
their relative speeds of oxidation ; but, owing to the removal of 
the county laboratory and other matters, the experiments had not 
been completed. 

Mr, St. V. C. Jones said that fires in the Freehold pits 
had always occurred where the soft and sooty coal was found. 
He could obtain samples of coal which would be similar to those 
obtained at the point of the fire. 

Mr. B. WooDWORTH asked whether the sooty coal was caused 
by the bending of the strata, and whether fires had occurred al 
the Granville pit. 

Mr. St. V. C. Jones thought that the bending of the strata 
had a connexion with the formation of the soft, sooty coal. He 
thought that the upheaval of the Coal-measures was probably due 
to the igneous intrusion, which now formed Lilleshall hill. The 
Coal-measures were crushed and broken, and this band of soft 
sooty coal was then produced. Fires had only occurred in the 
soft sooty bands of the Freehold pits, and he thought that, owing 
to their absence, no fires had occurred at the Granville pits. 



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TKt, Tn^tt^sfure Mine * 

n 



VqlXXXIILPlatbI. 



REFERENCES. 



.^.. FAULT AND OIIIIOTION OF THROW 

'.'r^.'. OiRICTION OF AIR-CURRINT C 

'.-"0.-T VfMTILATION-OOOR fD't:,- 

:::S'-1! RRAmci-tHeeT e^ 

FALLEN f' 

ooa% 9" 



OIRT 

SAND 

DIRT AND SAND 

■RICH -WALL 

SLACK 

SAND AND SLACK 




Datum 








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DISCUSSION — ^A GOB-FIKE IN A SHROPSHIRE MINE. 86 

Mr. F. E. Buckley said that he had arrived at the practical 
conclusion that the fire had been caused by the narrow pillar of 
coal beinf^ left in the centre of a large gotten area ; and, however 
difficult it might be to work that pillar of coal, in his opinion, it 
certainly should have been removed. Mr. Jones strengthened 
that opinion by stating that fires had always occurred where coal- 
pillars had been left. He contended that, at any expense, a 
narrow pillar should be removed, for what was the cost of work- 
ing such a pillar when compared with the loss of a district? 
Therefore, the warning of the paper should be not to leave narrow 
pillars of friable coal. 

Mr. G. E. Lawton asked whether the roof-coal was recovered 
from the goaf, and, if not, possibly this coal might be the means 
of initiating a gob-fire. He thought that Dr. J. S. Haldane 
proved conclusively that pyrites, when finely disseminated in a 
seam, actively participated in propagating gob-fires, as it 
caused disintegration of the coal and exposed larger surfaces 
thereof to oxidation. But he did not think that, when found in 
the lump-form, pyrites assisted in producing gob-fires. 

Mr. A. M. Henshaw said that this interesting paper intro- 
duced once more a question of vital importance to all engineers 
interested in coal-mining in North Staffordshire and the neigh- 
bouring county. The seam, in its natural condition, was not sub- 
ject to spontaneous combustion, but a gob-fire had occurred under 
circumstances that were abnormal. The cause was found in the 
conditions of the seam at the seat of the fire ; and at that point the 
coal was very faulted, very friable, very thick, and so soft that, by 
the pressure of the hand, a lump could be squeezed into dust. 
Whilst that condition of the seam obtained in that area, probably 
with the very best intentions but with the most unfortunate 
results, a course was adopted, which, from his experience of work- 
ing seams much prone to spontaneous combustion, he would at 
once describe as extremely risky. He had had a number of cases 
of gob-fires in small patches of faulted, soft and thick coal ; and 
he had been taught by experience that wherever coal of that 
description was found, it should be left solid in large areas or 
entirely worked out. He could quite see the diflSculty in this 
case of working out the whole of that area of soft and thick coal. 
The seam being 12 feet thick and part of a longwall district, it 



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86 DISCUSSION A GOB-FIKE IN A SHROPSHIEE MINE. 

would be very difficult to remove entirely the whole of the coal. 
He presumed that the district was sufSciently well-known, so as 
to determine the direction and extent of that faulty area. In that 
case, he would have suggested that a larger area, including all the 
soft coal and a certain margin of natural strata alongside of it, 
without cutting places through, should have been left absolutely 
solid. The fire broke out, at A, in a small area of goaf and along^ 
side a pillar of faulted coal (fig. 3, plate i.). Several places 
appeared to have been driven through the faulted coal, from one 
side to another, and at the same time the natural tendency of 
the ventilating current was from west to east, so that it was very 
likely that some leakage of air would pass from west to east into 
the middle of the gob, A. It was quite conceivable, owing to the 
coal being so soft, inferior and thick, that the gob, A, would 
contain a considerable quantity of waste-coal and the forcing 
of a small quantity of air into that mass would be sufficient to 
encourage oxidation. It probably would not be sufficient to bring 
about the necessary cooling, but it would be sufficient to supply 
new oxygen and to increase the temperature until it attained the 
ignition-stage. It was always easy to judge and draw conclusions 
after the event, and he always sympathized with engineers 
who had to deal with gob-fires. He invariably found that they 
were more to be pitied than blamed, but he wanted for the pur- 
pose of information to draw useful leesons from the cases that 
came before the notice of the members. As to the question of 
pyrites, he did not see that pyrites need have had anything to do 
with the fire : it was due to the soft and broken condition of the 
coal ; and, with multiplied surfaces exposed to oxidation, a rising 
temperature was naturally propagated. 

With regard to the method of dealing with the gob-fire, it 
showed a great deal of pluck and ingenuity on the part of Mr. 
Jones and his staff, and he was to be congratulated upon the 
efl:'orts that he had made to confine the fire, in the early stages, 
within close quarters. Considerable risks appeared to have been 
encountered, and he asked whether they had to deal with fire- 
damp. 

Mr. St. V. C. Jones replied that a little fire-damp had been 
found occasionally, and a small percentage was found when 
driving the heading from F to G (fig. 3, plate i.). 



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DISCUSSION — ^A GOB-FIRE IN A SHROPSHIRE MINE. 87 

Mr. A. M. Henshaw said that part of ihe scheme suggested by 
Mr. Jones was the filling of the road, above A, between the pack- 
wall and the solid pillar above, and he supposed that it would be 
8 or 9 feet wide. He had tried the plan of filling with non- 
inflammable material, but he had found that 8 or 9 feet of sand 
was not sufficient to prevent the conduction of heat to the solid 
coal beyond, and the heat would be sufficient to fire the pillar on 
the other side of it. A long time seemed to have elapsed between 
the outbreak on April 5th and the evidence of real tire on June 
6th, and he asked whether, during that time, any real fire had been 
seen. Mr. Jones had stated in his paper that the coal at the point 
where the fire started had the appearance of being " highly car- 
bonized, and looked as if it had . . . been subjected to great fric- 
tion." He would like to have a clearer idea of the meaning of 
'' highly carbonized," as he did not think that Mr. Jones meant the 
effect produced by heat, and he imagined that it would be similar 
to the " mushy coal " of that district. Great credit was due to Mr. 
Jones for his efforts, but he should have regarded the plan of 
fi'ghting the fire, at close quarters, as hopeless from the first in 
an area of longwall, and with a current of 15,000 cubic 
feet of air per minute. He thought that they were bound 
to be driven bcwjk to erect permanent stoppings in the main roads. 
He could hardly judge the conditions, but he thought it was 
possible that the fire might, some day, be observed at the en- 
trances of some of these roads, probably on the margin of the 
pillar of soft coal that had been left. He should advise Mr. 
Jones to strengthen the stoppings at Darlington's jig, on the 
face, and wherever possible. From what Mr. Jones had said of 
the pressure of the carbon dioxide in the pipe carried through the 
stopping in the new-opening level, he would imagine that air 
was finding an entrance ; and if Mr. Jonee could build side- walls 
alongside Darlington's jig, and reduce the pressure of the air 
into the heated goaf, he would be taking a further wise pre- 
caution. 

Mr. A. Hassam, in moving a vote of thanks to Mr. Jones for 
his paper, asked whether there was any water or damp about 
the seam. 

Mr. St. V. C. Jones said that there was no water at that point, 
and practically no moisture in the seam. With reference to 



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88 DISCUSSION — ^A GOB-FIRE IN A SHaOPSIIiaE MINE. 

the leaving of the pillar, on the face of it, it looked wrong, and, 
from a mining point of view, it was wrong, but it was left on 
account of safety. The roof was wretched, and it was found that 
sufficient cogging' material could not be procured to cog the 
place (the seam being about 12 feet thick at that point). They 
were afraid of accidents, and for that reason the pillar was left. 
This soft coal had been found in other portions of the Double 
seam, and it had with difficulty been removed. The seam being 
thick, a certain amount of slack fell into the gob, and fires had 
occurred frequently, where pillars had not been left. With 
regard to strengthening the stoppings and preventing the fire 
from coming through them, it had been decided, in case of the 
fire showing signs of coming through, to fill in the roadways 
to the west of the coal-pillar. The seam was practically free 
from gas, which had only been found in very small quantities. 
Its absence was due to the fact that the overlying seam of coal 
had been worked, and had practically drained it away. 

The Peesident seconded the vote of thanks to Mr. Jones for 
his paper, and it was unanimously approved. 



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TRANSACTIONS. 89 



MIDLAND IIS'STITTJTE OF MINING, CIVIL AND 
MECHANICAL ENGINEERS. 



GENERAL MEETING, 
Hkld at the Queen's Hotel, Babnslbt, Fkbbuaby 2€th, 1907. 



Mb. J. R. R. WILSON, Pbbsidbnt, in the Chaib. 



The following gentlemen, having been duly nominated, were 
elected : — 

Membebs^ 
Mr. William Badgeb, Mechanical Engineer, Jagersfontein Diamond Mining 

Company, Orange River Colony, South Africa. 
Mr. John Hbnbt Gbeaves, Mining Engineer, 69, Westgate, Wakefield. 
Mr. Thomas Wiohton Hood, Engineer, 120, East Ferry Road, Mill wall, 

London, £. 
Mr. Joseph Jaggab, Colliery Manager, Grange Moor Collieries, Flockton, 

Wakefield. 
Mr. T. W. Keillab, Mining Engineer, Wortley, Leeds. 

SlUDENT— 

Mr. NoBMAN Samuel Robebts, Mining Student, Aldwarke Main Colliery, 
Rotherham. 



Mr. R. SxTTCLiFFE read the following paper on ** The Import- 
ance of Scientific Mining in the Bamsley District": — 



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so MIXING IN THE BAENSLEY DISTRICT. 



THE IMPORTANCE OF SCIENTIFIC MINING 
IN THE BARNSLEY DISTRICT. 

By R. SUTCLIPFE. 

Miners living but very few miles from this district, and 
knowing something of its geological features must often envy 
those who are surrounded with so large a number of valuable 
coal-seams, which would be highly prized in other districts, 
especially by those who may have happened to be connected 
with the working of seams in which, if a man has a long pick- 
blade, he has some difficulty in turning the second point to the 
coal when the first has become blunted. To men employed 
in the getting of such seams, what is considered in the Bamsley 
district to be a thin seam, would to them appear to be a moderately 
thick one. For clearness in this paper, the writer will assume all 
seams under 3 feet in thickness to be " thin seams " and all seams 
over 3 feet to be " thick ones." In thinking over the subject of 
mining in the neighbourhood of Bamsley, one cannot always say 
whether the thick seam bearing the name of the town has been of 
that great benefit to the locality which, under other circumstances, 
it might have been. However this may be, the fact that it is being 
exhausted in the neighbourhood makes it necessary for miners, 
who live in the town, to travel farther afield in order to reach 
their daily work. As the nearest collieries, now at work, become 
worked out, if the thinner seams continue to be neglected, the 
daily journey of the miner must increase unless he moves into 
the country; and, as human endurance is limited, it follows 
that the miner's power or capacity for useful or productive work 
will be proportionately reduced. A good service of trains may 
exist to convey the workmen to and from their work ; but wait- 
ing, even for a short time, for a train to move so starves the body, 
especially after a day's work in a warm mine, that it is question- 
able whether this train-accommodation is altogether to be desired. 
Until recently, however, these disadvantages were probably 
unavoidable, owing to a great extent to the inability of the 



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MIXING IX THE BARNSLEY DISTEICT. 91 

ordinary miner who has served a large portion of his life in 
a thick seam to adapt himself to the conditions of work in a thin 
one, and to the length of time required for him to reach that 
degree of efficiency which would enable him to earn a fairly good 
day's wage in the latter. Of course, it follows that the sons would 
go with the father, and also become expert in the work of the thick 
seam only. If this be so, it will easily be seen that the prosj)ect of 
utilizing the thin seams under and around Barnsley in the early 
future is not very promising, unless improved methods of work- 
ing are adopted. In addition to this, the difficulties of the 
colliery-owner in utilizing thin seams cannot be ignored; 
because many departures must be made from the methods adopted 
in getting thick seams : — (1) The royalty-rent payable to the 
landlord should be much more than proportionately lower than 
that for the thick seam — a fact not always readily recogpaized by 
the landlord or his agents. (2) If the colliery-owner were not 
doing very well out of his thick coal, he could hardly expect to 
improve his position by embarking in the work of a thin one; 
while, if he was doing well out of his thick one, he would naturally 
"" let well alone," especially as he would have to meet the royalty 
question just referred to, with, perhaps, the expiration of his 
lease also in view. (3) He would have to procure plant, corves, 
etc., suitable for thin seams, and work these while his plant, 
suitable for the thick seam, might be lying idle. 

When it is remembered that the total thickness of coal 
underlying Barnsley, in the several beds which are known to be 
of a workable thickness, exceeds 40 feet, it seems difficult to 
understand why the three partners in the business could not come 
to a mutually beneficial understanding and unlock this vast 
amount of wealth, instead of letting the grand and fascinating 
industry of coal-mining glide, slowly it may be, away from 
the town. From the landlord's point of view, one would have 
thought that the proverbial half-loaf would be better than no 
bread, especially as the working of thin seams seldom, if ever, 
injures the surface in uneven country. Colliery-owners, too, 
often have shafts sunk through thin seams, which, if away 
from the close proximity of the thick coal-seam for which the 
shafts were originally sunk, would be of very considerable value ; 
while the workmen, even if they were obliged to take rather less 
wages, would find a great advantage in having their work within 

VOL. ZZXI1I.-1M6-1M7. ^ 



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92 MINING IN THE BARNSLEY DISTRICT. 

easy distance from their place of abode, and consequently would 
have more time to spend at their homes for rest and recreation as 
well as being able to avoid the disadvantages of either long walks 
or train- journeys to or from work. 

Under these circumstances, then, it is perhaps worth while to 
enquire how far it is feasible to turn some of the thin seams which 
abound in the neighbourhood to account. These, if only situated 
a few miles distant from Bamsley, would be of much importance, if 
not of great value. In order to show that many of the thin seams in 
the district are of importance to the three parties referred to, it is 
only necessary to say that, within 8 or 10 miles of Bamsley, seams 
not more than 18 inches thick are being worked, and are 
at least paying their way under careful management, even with- 
out the mechanical aids obtainable at the present time. And 
this is being accomplished even where the cost is greatly increased 
by a charge of at least 8d. per foot for the ripping of gates 36 to 60 
feet apart, and by the payment of a high rate for tramming 
(owing to the almost universal use of small corves in these thin 
seams). In some districts, for instance, in parts of Scotland and 
Ireland, it is customary to cast the coal to the gate-side in order 
that it may be filled into large-sized corves ; but in West York- 
shire the tubs are taken through the working-faces even in thin 
seams, with the result that corves which will hold only 3 cwts. of 
coal are frequently used. And it is not uncommon to see a 
miner, lying on his back and wedging himself between floor and 
roof, push a corf out of some diflScult position with his feet. 
Under such circumstances, it is impossible to get large coal into 
a corf. 

The majority of the seams around Barnsley, however, are not 
thin enough to experience these disadvantages ; as many of them, 
such as the Woodmoor, Summer, Abdy, Kent Thick and Beam- 
shaw seams (all overlying the Bamsley seam) approach 3 feet 
in thickness. All these seams have the advantage of being 
passed through at various places by sinkings to the Bamsley 
seam ; and consequently they should be comparatively free from 
water. Below the Barnsley seam, the Swallow-wood, Lidget, 
ThomclifEe Thin, Swilly and Silkstone Four-feet, all thin seams 
according to the writer's definition, are pierced by pits in the 
vicinity sunk to the Silkstone seam. In this list the writer has 
omitted the Parkgate seam, as he does not class it amongst the 



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MINING IN THE BARNSLEY DISTRICT. 98 

thin seams in tlie Bamsley district, except where it is divided by 
a thick band of dirt. In West Yorkshire, the Farkgate or Old 
Hards, as it is called there, a very valuable seam^ is divided by 
no less than 30 feet of band, and the lower portion of it is being 
worked down to 16 inches in thickness. In mentioning the 
thickness of 15 inches, the writer does not take into account some 
4 to 6 inches of dirty, useless coal found next to the roof, known 
as " dross " or " lime coal," which is invariably oast into the 
goaf when there is room for it. Seeing, therefore, that so many 
coal-seams are already passed through in this populous neighbour- 
hood by shafts, it seems a pity that so little effort is being made 
to win them, even though some of the pits have been abandoned 
because the thick seams have been worked out. 

In this rapid survey of the subject, it has been shewn that 
formerly much could be said for leaving the working of these 
seams, for the time being, in abeyance. This, however, is no 
longer so, because appliances are quickly being matured and 
perfected by practice, such as will enable the thinner seams either 
to be got concurrently with the thicker ones (where the latter 
are still unexhausted), or through the abandoned shafts which 
have pierced them. Had capital to be found to sink pits to the 
thinner seams alone, there would be some excuse for not troubling 
about them while the thick ones lasted ; but, where shafts already 
exist, it seems strange that so little effort is made to get them. 

It may, however, be almost taken for granted that, when the 
thin seams are worked, coal-cutters will be employed to under-cut 
them, and conveyors used to put the coal into corves in the 
gateways or pass-byes, very few of which will be employed or 
required. In this way, manual labour can be employed in the 
less laborious operations of coal-getting, such as operating 
machines, placing the coal on face-conveyors, timbering, etc., 
while machinery will be adopted to do all the other work. In 
this way only will it be possible to work thin seams on anything 
like a favourable basis in a thick-coal district, where miners have 
not been trained to thin-coal mining. By the adoption of appli- 
ances now available, the output from even thin seams may be 
made to approach more closely to that of the thick seams than 
was formerly possible, whilst less work will be required in rip- 
ping gates, which then become unnecessary. 

It has already been mentioned that, in getting some thin seams 



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94 MIXING IN THE BAENSLEY DISTRICT. 

by hand-labour, it waa neceflsaxy to rip or make gateways for 
every 36 to 60 feet of face. Now, with conveyors at the face, the 
distance between the gateways need not be less than 600 feet, and 
the main gateways may be 1,000 or 1,200 feet apart, so that 
every gateway may be, and possibly will be, an engineplane pro- 
ducing several hundred tons of coal per day. In many ways 
this, in itself, is a very great benefit in working any mine at the 
present time. The fact that 76 per cent, of the gateways are cut 
off saves the cost of making such gateways, of the daily 
examination of this proportion, and of the rails, sleepers, nails, 
ventilation and general repairs. The deputy, being relieved from 
the examination and care of 76 per cent, of the gateways, can 
bestow more time on the coal-face, and on getting out his work, 
which in itself is often of much importance. Again, the cutting off 
of so many gateways along the face is of importance wiiere coal- 
cutters are used, because where a large number of gateways exist 
there is great difficulty in keeping the gate-ends clear and in 
finding room for the debris produced by cutting, which accumu- 
lates between the pack-walls and the coal-face — often leaving too 
small a space for expeditious working, and sometimes burying 
timber which would otherwise have been withdrawn. 

All these advantages, however, are small compared with the 
great saving in labour. The getting of empty tubs into a coal- 
face, filling them there, and getting them out of the face and on 
to the gate-rails when full, is neither light nor pleasant work 
in any mine, no matter how thick the seam may be, but is 
especially laborious work in a thin seam. It is not, therefore, 
surprising that, when miners become even slightly acquainted 
with the working of face-conveyors, they do not wish to return to 
tub-filling. Objection is sometimes raised to the me of con- 
veyors in a seam where two or more sorts of coal are filled 
separately at the face; but a moment's consideration will show 
that any such circumstance need not be considered detrimental 
to the working of them, provided that they are worked systemati- 
cally. At present, the different kinds must be sent out 
separately by first filling one or more corves with one 
kind of coal, and then one or more oorves with the other kind. 
The same rule holds good in loading the conveyors: the only 
difference being that, with hand-filling, each man may fill which- 
ever kind of coal he wishes, irrespective of the kind which others 



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MIXING IN THE BARNSLEY DISTRICT. 95 

may be filling ; while, with a conveyor, every filler must load the 
same kind of coal at the same time, and when a change is made 
from one kind to another, no filler must fill the new kind until 
the whole of the first quality on the conveyor has passed him. 
This will cause very little inconvenience, as the fillers, being in 
touch with one another, can readily agree at what time the change 
from one kind of coal to another shall take place, and can arrange 
that the attendant at the head of the conveyor shall change the 
corves at that time. The fact that a corf may not be full at the 
time when the change is made may appear to present a difficulty, 
but this is more apparent than real. Flat^sheets will doubtless 
be used in connection with conveyors, and a jjartly-filled tub can 
easily be laid aside and its filling completed as soon as the kind 
of coal that it contains is again sent over the conveyor. 

Whilst the conveyor, for many reasons, seems to be the natural 
complement of the coal-cutter, it is also applicable for use in 
hand-holed faces where a good or fairly good roof exists ; and it 
will probably revolutionize the getting of coal, even in thick 
seams, where a good length of face can be cut. In such a face, 
the conveyor may be fixed, say, 4 feet from the coal, to enable 
the cutting machine to remain in any part of the face during the 
filling of the coal, or even to cut the coal while coal in other 
portions of the face is being filled. This is an advantage, the 
effects of which may be far-reaching. It certainly overcomes the 
inconvenience of compelling the machine to cut exactly from 
stable to stable, and no more, in a day : thus doing away with 
stables in or along the face, and allowing the cut to be made 
gradually inward ; or the machine may be pushed into position 
by jacks or otherwise while cutting. Further, a sufficient number 
of machines can be put on a face, to cut any length of coal that 
may be desired. Such a face, say, 1,200 feet in length, can 
be dealt with by two conveyors delivering on to a gate-conveyor j 
and such a face, 5 feet thick, with a 5 feet undercut would, 
in round numbers, produce 1,000 tons or 2,000 corves, each 
holding 10 cwts. To deal with this number of tubs in 8 
hours would require 4 tubs to be filled per minute. This, how- 
ever, is only the capacity of one face-conveyor, which not only can 
fill, but has filled similar corves at the rate of one in 15 seconds. 

The writer, however, is dealing with thin seams, and probably 
only 400 tons of coal per day would be obtained from a face 



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96 MINING IN THE BABNSLEY DISTEICT. 

1,200 feet long*. Tkis quantity can easily be dealt with by two 
conveyors, each 600 feet long, delivering on to a gate-conveyor 
carrying the coal to the corves at the pass-byes. The latter con- 
veyor may be of any length and capacity. It is not necessary to 
refer to the smaller number of corves required under this system. 

It will, of course, be readily understood that the pass-bye will 
be placed at the delivery-end of the conveyor, and it will be as 
readily conceived that, to deal with even 400 tons per shift in a 
passage or gateway with either horse or hand-labour, is no easy 
matter ; while it is inconvenient to have to keep shifting up the 
main-rope haulage-wheel at short intervals. A small main-and- 
tail-rope hauling-engine could, however, be placed in the main 
pass-bye at the return-wheel, with a small return-wheel at the 
conveyor-end for drawing the corves between the conveyor and 
the engineplane or main pass-bye. 

The writer has designed a small hauling-engine to deal with 
this class of work, which, he thinks, will find favour with colliery 
managers even for more extended use. It is suitable for endless- 
rope haulage ; and the rope, contained on two drums, can be 
readily extended as the gateway lengthens. It can be operated 
by compressed air, electricity, or from the return-wheel shaft of 
the main haulage-rope. 

It has been already stated that, where hand-work prevails, 
small tubs must be provided if thick and thin seams are to be 
worked simultaneously ; but, where conveyors are used, this is un- 
necessary, as the large tubs may be employed in even the thinnest 
seams. Every colliery manager knows the trouble incurred at 
a colliery when tubs of various sizes are used concurrently. 

Thirty years ago, the writer used coal-cutting machines in a 
seam 18 inches thick, in the largest colliery in Ireland, where the 
measures dipped 1 in 5. Sledges were used at the face, the gate- 
ways were spaced 135 feet apart, and the tubs were filled in the 
gateways. As a consequence, it was found that, if the average 
selling price of the coal could be maintained at 7s. 6d. per ton, a 
fair profit could be made. Unfortunately, that price was not 
obtained, otherwise the colliery, in all probability, would be 
working still. The demand did not reach one-fourth of that 
expected : consequently the coal-cutters were taken out, and were 
afterwards brought to England, and the writer believes that some 
of them are working in Yorkshire to this day after thirty years' 



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MINING IN THE BABNSLEY DISTRICT. 97 

service. In Yorkshire, the writer has worked coal-seams, with 
coal-cutters, down to 15 inches in thickness at a profit, and in 
the Bamsley district, he is interested in coal-cutters working 
the Abdy seam, which he has no hesitation in saying is admirably 
suited for such machines. Seeing, then, that the use of 
machinery for getting coal is no longer problematical, and that 
its application to the thin seams of this district is quite feasible, 
the wonder is that coal-cutting machines have not been more 
largely used. Notwithstanding the difficulties already referred 
to, it is certain that, in the absence of thick seams, the thin 
fleams found in the district would become valuable, and if worked 
would give employment to a large number of people as well as 
to coal-cutters. 

It is, at least, of some interest to the district generally that 
an industry so long established, and of such importance as coal- 
mining, should not be allowed to decline even slowly; and, if 
this is to be^prevented, the question of utilizing some of the seams 
now lying neglected must be considered in earnest. Fortunately, 
circunLstances in the neighbourhood are unusually favourable 
for this, owing to the numerous abandoned shafts by means of 
which access can be obtained to the thinner seams that have been 
entirely ignored by the former proprietors, and now lie close to 
these shafts waiting to be operated by some enterprizing capitalist. 

The writer does not forget that thin seams in the Bamsley 
district have, from time to time, been broken into, and that here 
and there attempts have been made to turn them to account, but 
with little success. Such attempts, however, were not made 
either in the manner or by the means which were likely to be 
successful. In order to achieve success under present conditions, 
thoroughly organized, systematic, and energetic management is 
of the first importance. To ensure this, the stafi should consist 
of men knowing the requirements necessary for the successful 
working of up-to-date methods and machinery. The courtesy 
and fraternity at present prevailing amongst Yorkshire coal- 
owners and managers greatly facilitates the acquisition of these 
attributes or qualities by allowing friendly visits by interested 
officials to neighbouring collieries; and the writer hopes that 
this benevolent spirit, with the good that results from the mutual 
interchange of ideas and suggestions, will long prevail. 

Of all people, the working miners of the district should be 



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98 MINING IN THE BARNSLEY DISTRICT. 

particularly interested in the opening out of thin seams. The 
writer has already remarked that it is doubtful whether the 
Bamsley seam is of that great benefit which it might have been 
under other circumstances, because its extreme value made nearly 
all the other seams appear almost valueless; but, from the 
workers' point of view, he thinks that the thinner seams ought to 
be considered of greater importance, because more labour must 
be employed to produce the same amount of coal. 

Even with modern machinery and appliances, it can hardly 
be expected that a man in a seam 3 feet thick can get coal as 
quickly as in a seam 10 feet thick. Under these circumstances^ 
then, can the aid of the miner be counted on, in developing the 
numerous thin seams which are found in the district? The 
writer has no misgivings on the matter, and unhesitatingly says 
yes, if properly dealt with. The writer has been amongst the 
Bamsley miners, and knows many of them, and he has no hesita^ 
tion in saying that there are quite as many real heroes amongst 
them as amongst any other miners in the kingdom. No person 
can doubt that miners all over our land are real heroes in case 
of need, when the numerous calamities which have occurred 
within recent times are recalled. In proof of this statement^ 
reference need only be made to one case : not many miles from 
Bamsley an accident occurred in a shaft, and several men were 
precipitated from a scaffolding into the pit-bottom. When the 
rescuers got down they found one man hanging head downwards 
on a crook, which had cauight in one of his boots. This man 
knew well enough that if his bootlace gave way it was instant 
death for him, still he implored the rescuers to hasten to his 
mates in the bottom, and relieve them before relecising him from 
his dangerous position. Should not such heroism be printed in 
letters of gold ? How prevalent such cases are amongst miners in 
times of need ! Can it be doubted then that such men will try 
to assist in all legitimate enterprise for the advancement of their 
calling, and the good of all around them ? 

Although the writer has not mentioned any of the seams of 
the Lower Coal-measures (those below the Silkstone seam), it is not 
because he attaches no importance to their value, but because it 
is quite unnecessary to go to the expense of opening out and 
working the deeper seams when so many exist in the district at 
much shallower depths. It is well known, however, that the 



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DISCUSSION — MINING IN THE BARNSLEY DISTKICT. 9^ 

lower seams play an importaat part ia a large area of the West 
Yorkshire coal-field, where the Beeston and Black Bed seams 
are extensively worked. Below these again are the Halifax 
seams ; these seams are even of greater extent, reaching to the far 
south of Ireland, except where they have become denuded, and 
they enter largely into tlie production of coal in Lancashire as* 
the Mountain mines. 



The Pkesident (Mr. J. E. R. Wilson, H.M. Inspector of 
Mines) said that the members would ag-ree with. Mr. Sutcliffe,. 
when he stated that, to achieve success, '' thoroughly organized,, 
systematic, and energetic management is of the first import- 
ance," whether they worked coal at Bamsley or in any other part 
of the country. The members were well prepared to admit that 
amongst miners, as a class, there were real heroes ; but he ques- 
tioned whether a man, although he would hang. down a shaft at 
the risk of his life, would go to work in a seam, 2 feet 6 inches 
thick, if he had the chance of working in a seam 6 feet thick. 
He proposed that the thanks of the members be given to Mr. 
SutclifiEe for his paper. 

Mr. E. W. Thibkell, in seconding the vote of thanks, said 
that a paper was written by the late Mr. Robert Millar, sixteen 
or seventeen years ago, on " The Coal-field adjoining Bamsley,"* 
and it would be interesting to compare the two papers. Mr. 
Millar said that he did not aim at a very great deal, but he 
hoped to cause people to think; and he (Mr. Thirkell) agreed 
that, if they could get people to think, particularly in matters of 
mining, they would be doing good. Mr. Sutcliffe would cause 
people to think, if they only read the title of his paper, because 
some engineers thought that if anybody knew anything at all 
about getting coal, they did at Bamsley, and also how to get it 
in a scientific way. But with the Bamsley seam, engineers did 
not need to trouble very much about science in the olden days. 

Regarding the subject of Mr. Sutcliffe's paper, the 
situation was hardly that the seams under Barnsley were not 
valuable, but that the necessity for working them had not yet 
arisen. Bamsley engineers were quite as shrewd as others, and 
they would not let valuable mineral property be lost for ever as 

• Trans. Inst, M. E., 1890, vol. ii., page 7. 



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100 DISCUSSION — MINING IN THE BARNSLEY DISTEICT. 

stated by Mr. Millar in his paper. Mr. Sutcliffe and everybody 
else could rest assured that Barnsley engineers knew full well 
that it was there, and that they were only waiting* for the proper 
time to work it. Respecting the statement that appliances were 
being improved and perfected, he (Mr. Thirkell) said that was 
so, but they were not yet perfect, and when they were, Barnsley 
engineers would bring them into play in working the thinner 
seams. He quite agreed that it would not have to be done in a 
half-hearted way, nor would it be advisable for somebody in 
prosperous times to start to work a thin seam, then leave it and 
probably ruin it and himself, and he also agreed with what was 
said regarding the management, which must be " thorou^ghly 
organized, systematic and energetic." 

Officials and workmen must be properly educated in the use of 
the machinery to be applied, and trained men accustomed to the 
work would be required. Machinery for coal-cutting, convey- 
ing, etc., required skilled men, who, by long practice, were able 
to avail themselves of every advantage, and, notwithstanding 
Mr. Sutcliffe's belief that the miners in the district could be 
counted upon to develop the thin seams (" if properly dealt with," 
whatever that meant), it was no disparagement to a Barnsley 
collier to doubt his ability to compete successfully with a trained 
thin-coal miner, in working thin seams. There was no disputing 
the fact that coal-values were relative, and unless they could put 
the thin seams on the market at a cheaper rate than the Barnsley 
seam, they would prefer to have the Barnsley seam ; and not only 
that, but the difference in price between the Barnsley and other 
seams would have to be such as would equalize at least all the 
economies brought about by the use of elaborate machinery, both 
aboveground and belowground. He (Mr. Thirkell) believed that, 
with the aid of machinery, seams which were regarded as worth- 
less now would, in time to come, be worked. Several of the 
seams contained thin bands of dirt, which made it impossible to 
sell the coal as lai'ge coal ; but, when crushed, washed and sized, 
it could be utilized for coke-making and for furnaces specially 
made for firing by small coal. He (Mr. Thirkell) was sure tihat 
these seams would be worked when the time came: a living 
was now made out of seams that our fathers considered worthless, 
and the recovery of what formerly was taken as waste or unpro- 
ductive, was now the question of the day. The members could 



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DISCUSSION — MINING IN THE BAENSLEY DISTRICT. 101 

Bee what was being done in this respect in gas-works, soap- 
works, bye-product plants, etc., and in years to come, those who 
came after us would do as we were doing now. 

In Mr. Millar's paper, which dealt principally with the 
seams below the Bamsley bed, reference was made to the diffi- 
culties to be met with in dealing with the water. These difficulties 
were far greater to-day than when Mr. Millar wrote his paper. 
The water in the old shafts probably alluded to by Mr. Sutcliffe 
was practically at a level with streams on the surface, and the 
question was one which the mining engineers of the district 
had long had under consideration. When they looked at the list 
of members, and particularly at the list of past-presidents, the 
members saw a list of mining engineers upon whom they could 
depend to cope with these difficulties and to see that the mineral 
wealth under Bamsley was not wasted. In early Parliamentary 
elections, much was said about Bamsley being the ** right eye " 
of Yorkshire. He thought that the members could take it for 
granted that when the time came for the seams of which Mr. 
Sutclifie had spoken to be worked, that " right eye " would be 
Tery wide open indeed. 

Mr. J. L. Marshall said that he agreed with the spirit in 
which Mr. Sutclifie's paper had been written, but the members 
were also bound to agree with Mr. Thirkell's views as to the 
difficulty of the present development of these thin seams. The 
time for their working had not yet arrived ; but, when it did, he 
thought that the seams would be worked with the aid of coal- 
cutters, coal-washers and coal-conveyors. He asked whether the 
writer had had experience of the use of conveyors in thin seams 
with soft, spongy bottoms and similar tops. 

Mr. H. Rhodes thought that the key of the position lay in 
the question of average selling-price. If the average selling- 
price could be maintained at 28. or 3s. a ton more than was 
obtained at present, almost any seam might possibly pay to work, 
assuming that the wages-rate remained the same. It might be 
taken as certain, however, that the wages would increase as the 
selling-price increased. In abnormal times any seam would pay, 
but such a subject as this could only be dealt with on a normal 
basis ; and, when the thin seams had to be worked in competition 
with the thicker seams, in these days it would be impossible to 



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102 DISCUSSIOX MINING IN THE BABNSLEY DISTRICT. 

work them succeaafully unless they were so specially situated as 
to obtain some exceptional advantages in the selling-price. If 
Mr. Sutcliffe looked further into the matter, he -would find that he 
was hardly correct in stating that the thin seams above the 
Bamsley bed would be comparatively free from water. If he 
(Mr. Rhodes) was not mistaken, many of them were water-logged 
at the present time ; and, in several instances, their working had 
been abandoned owing to the water-difficulty. 

Mr. W. Walker (H.M. Inspector of Mines) said that the 
statement that no thin seams were being worked in the Bamsley 
district was hardly correct, as thin seams were being worked 
at Barrow, Dodworth, and other collieries. It seemed to him. 
very desirable that the thin seams should be worked simultan- 
eously with the thick seams, and it would be an encouragement 
if royalties coidd be arranged on a tonnage-basis, in proportion 
to the thickness and qualities of the seams. 

Mr. H. B. Nash said that, in 1892, he read a short paper before 
the Bamsley Naturalist and Scientific Society on " The Un- 
worked Coal-seams of Bamsley and District," and he then stated 
that, owing to the difference in their thickness, their inferior 
quality and their enhanced cost of working, they could not be 
successfully worked in competition with the thicker and more 
valuable Barnsley bed. On that account their development had 
been comparatively slow, but sufficient had been done to show 
that a very valuable coal-field remained to be developed and 
worked, as time and circumstances warranted. He thought that 
statement met the whole of Mr. Sutcliffe's arguments, as the 
time had not arrived for the successful working of these seams. 
When the time came, the necessary appliances would be utilized ; 
although the experience of the last few years in the matter of 
these thin seams had not been such as to induce any capitalist to 
take them in hand. 

Mr. T. W. H. Mitchell said that the miner whom Mr. 
Sutcliffe praised so much, and who did display courage in times 
of stress and danger, forgot himself at such times and went to 
the succour of his companions ; but in times of arranging price- 
lists he went for himself as against his employer. In two or 
three cases, where the upper seams had been tried in pits in 
which the thicker seams had been nearly exhausted, wages had 



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DISCUSSION — MINING IN THE BARNSLEY DISTRICT. 108 

T>een tlie gxeat obstacle to successful working. In his opinion, 
the miners of Bamsley would have to learn to work in thinner 
seams, and in so doing must expect the wages to be less. The 
workmen ought to consider that their proportion of the develop- 
ment of the thinner seams was given in the lesser wages that they 
would accept, whilst the landlord would have to take less money 
for his royalty, and the owner would take his smaller profits. 
Mr. Marshall had referred to the working of seams with soft 
bottoms. He had known one or two instances where a road had 
been left beautifully clear at the end of a shift, but when the 
miner wished to return to his work he could not get in because 
the roof and the floor were practically meeting; and some 
method must be devised for dealing with that difficulty. Mr. 
Sutcliffe had stated that the working of thin seams would not 
injure the surface: unfortunately, he (Mr. Mitchell) had had a 
different experience in the working of a bed of clay at about the 
same depth from the surface as the thinner seams referred to in 
Mr. SuteliSe's paper. 

Mr. T. QiLL said that he was afraid that some of the seams 
under Bamsley were not so valuable as Mr. Sutcliffe represented 
them to be. He knew a place in the borough of Bamsley, where 
the Silkstone seam was worked and it had not a very profitable 
section. It consisted of inferior coal, 2 inches ; top coal, 1 foot 
7 inches ; dirt, 8 inches ; coal, 4 inches ; dirt, 1 foot 2 inches ; 
and bottom coal, 9 inches. The 4 inches of coal were of very little 
use, as splitting it off and picking out the dirt was not worth the 
trouble, so that only 2 feet 4 inches of coal, together with 2 feet 
4 inches of dirt, was left. It had been proved that the Silkstone 
seam under Bamsley deteriorated in quality as it extended east^ 
ward. Therefore, in his opinion, the Silkstone seam under 
Bamsley was not worth working at the present day. 

Mr, R. Sutcliffe, replying to the discussion, said that his 
chief point was that the thin seams should be worked, rather than 
that the collieries, from which thick seams had been extracted, 
should be abandoned. He was strongly convinced that the thin 
seams were valuable. 



Mr. N. W. RotJTLEDGE's paper on " The Most Suitable Form 
of Guides for Cages for Winding from Deep Shafts : 1,500 Feet 
and Deeper," was read as follows : — 



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104 GUIDES FOR CAGES. 



THE MOST SUITABLE FOEM OF GUIDES FOR CAGES 
FOR WINDING FROM DEEP SHAFTS : 1,500 FEET 
AND DEEPER.* 



By N. W. ROUTLEDGE. 



In selecting the form of guides to be adopted in a deep shaft, 
the mining engineer is governed by many considerations. He 
is confined practically to two forms : the rigid and the flexible. 
In the former class, he may have wooden guides, iron or steel 
rails, and H or T -section girders ; and in the latter, he has the 
choice of wire-rope or round-iron rods. 

Wire-rope Guides, — The writer considers that, under ordinary 
circumstances, wire-ropes are the best kind of guide for a deep 
shaft. The advantages are simplicity, smooth running of the 
cage, little risk of derailment and long life. The disadvantages 
are increase of weight on the headgear, and sag or sway in the 
shaft, necessitating more clearance in the shaft than with rigid 
guides. 

The usual construction of guide up to 4^ inches in circum- 
ference contains seven wires; and over this size, up to, aay, 5i 
inches in circumference, twelve wires are twisted together. For 
still larger sizes, they are made in the form of a rope, that is, 
six strands of seven thick-drawn wires are laid together. In 
selecting the size to instal, care must be taken to make allow- 
ance for the weight of the rope, for the weight hung on it, and 
for the wear of the guide. 

The large wires give, as compared with an ordinary rope, 
increased wearing surface and a longer lapse of time before the 
wires are worn through. The best guides are made of charcoal- 
iron, but this being practically unprocurable, they are usually 
made of dead soft steel. 

^ This student's prize essav is printed in the TranMctions at the special 
recjuest of the Council of the Midland Institute of Mining, Civil and Mechanical 
Engineers. 



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GUIDES FOB CAGES, 106 

Fixing the Guides, — ^There are several methods of fixing 
guides, the most usual being as follows : one end of the rope is 
clamped in the headgear, by a specially made clamp, AB, to 
suit the size of rope, and after passing through a baulk or girder, 
G (figs. 1 and 2, plate ii.), the rope hangs down the shaft as far 
as the sump. In this method of clamping the rope, it is passed 
througb an eye-hole or baulk to give it steadiness ; and a weight 
of, say, 5 or 6 tons to give tension, and as far as possible to 
prevent sway, is hung on the end. Fig. 3 (plate ii.) shows an 
arrangement in the sump with the attached weights. The 
weights are most conveniently handled when built up of a series 
of small blocks weighing 5 or 6 cwts. each. It is important that 
the weights should not be submerged in water, otherwise, their 
weight, and therefore their efficiency, would be decreased in 
proportion to the weight of water displaced. Where the sump 
is shallow, or not roomy, a system of levers might be adopted to 
decrease the size of the weight. In another arrangement, the 
rope is clamped in the sump, and the weight put on at the surface 
(fig. 4, plate ii.) : this takes up all variation in length due to 
stretch, or difference in temperature. One weight may also be 
made to suffice for two ropes. 

Life of Guides. — ^The life of the guides varies under different 
conditions from a few years up to 20 years. The chief factors 
are atmospheric conditions, whether the shaft, is wet or dry, and 
whether there is any acid in the shaft. Any or all of these com- 
bined might cause the guides to corrode very qdickly. The 
writer suggests a system whereby lime-water, or some other 
alkali, coidd be constantly applied to the guides to neutralize 
the acid. 

Shoes or Runners, — ^Fig. 5 (plate ii.) shows an ordinary 
runner for rope-guides. They are made 12 or 14 times the 
diameter of the rope in length, and are lined with brass: the 
liner being renewable. The runners are bolted to the side of 
the cage. Rollers have been tried, but do not give satisfaction. 

Position of Guides, — ^The position of the guides varies accord- 
ing to the size of the cage, and according to the local circum- 
stances met with in the shaft. The writer favours the us© of 



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106 GUIDES FOR CAGES. 

four guide-ropes to each cage, fixed practically at the comers 
with rubber ropes (afterwards described) between the cages (fig'. 
6, plate ii.). These are similar in construction to the guide-ropes, 
and are fixed in the same manner at bank and in the sump. They 
are not in any way connected to the cages, but are simply used as 
a buffer between the cages at meetings and for the cages to rub 
against when winding. Blocks of wood are attached to the 
«ages, so as to make sliding contact with these ropes. 

Clearance, — The writer considers that it is of more importance 
to have clearance between the cage and the shaft-side than 
between the cages at meetings. Where rubber ropes are used, 
there is no danger of collision ; but, should the cage catch the 
«haft-side, irreparable damage may be done. A clearance of 
about 18 inches may be left between the cage and the shaft- 
side, but the writer would let ihe cages make the contact with 
the rubber ropes as nearly constant as possible. 

Vibration and Sway. — The vibration of the ropes produces 
swaying of the cages, and it is impossible to apply sufficient 
tension on the guides to obviate this disadvantage. Mr. Charles 
Snow, at South Kirkby colli eiy, uses a very ingenious arrange- 
ment, which has proved satisfactory. He has, by varying the 
weights, tuned up the ropes to different tensions; thereby, the 
vibia-tions producing the sway are of different periods, and tend 
to counterbalance each other. 

Extra Weight on Headgear, — The weight of the guides, 
together with that of the weights hanging at their ends, applies 
an additional stress on the headgear, which must, in consequence, 
be specially designed to resist safely the increase of weight. As 
an example : eight guide-ropes, 4J inches in circumference, 1,500 
feet long (weighing 6f pounds per foot), with eight weights of 5 
tons each, puts a weight of 75^ tons on the headgear. With two 
rubber ropes, similar in size, the weight would be increased to 94 
tons. It will at once be recognized that this is a tremendous in- 
crease, when compared with a headgear which has only to carry 
the weight of the cages, etc. 

The writer suggests that some member should draw a paral- 
lelogram of forces, and find the position of the backstay on the 



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Fio. l.-SiDE Elevation 4ation of Weighted Quadrant. 




FlQ. 2.-PLAN OF Oi 



Runner or Shoe. 



SotU; 1 Foot to 7 Inok, 



' U 
( ! ( 



1 > 



-^Sj A 





Fig. 3.— Side EH 



^ \ /h{\ 



, — i" 






iJI^JiMli^li'J-UiiMl 



''n^. 




5ctf/«t ^ gca/g. tf /M to 7 /ifoA, 



Midlojui JnstUiUe ofMvwuf.t 
Tranaactufi 



Vbx.XVnL,PLATE L 

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GUIDES FOB CAGES. 107 

headgear. If the weight of the guides, etc., be included, the 
resultant is at a very singular angle to apply a backstay. 

Arrangement of Ropes. — Fig. 6 (plate ii.) shows an arrange- 
ment for rope-guides in conjunction with rubber ropes, and gives 
the writer's ideas with regard to their positions for deep and 
rapid winding. Four guide-ropes, A, are applied to each cage, 
B ; two rubber ropes, C, are placed between the cages ; and two 
wooden blocks, D, engage the rubber ropes. The limit of clear- 
ance might be taken at 8 inches between the sides of the cages, 
and at 18 inches between the comers of the cages and the shaft- 
side. 

The guides should be kept well lubricated ; and attention to 
this item will prolong their life and reduce friction. 



Mr. A. J. Kennedy's paper on " The Most Suitable Form of 
Guides for Cages for Winding from Deep Shafts : 1,500 Feet and 
Deeper," was read as follows: — 



YOL. ZZXni.-lM0.UO7. 



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108 GUIDES FOB CAGES. 



THE MOST SUITABLE FORM OF GUIDES FOR CAGES 
FOR WINDING FROM DEEP SHAFTS : 1,500 FEET 
AND DEEPER.* 



By a. J. KENNEDY. 



I . — Introduction. 

When dealing with winding or any other question relating 
to the practical working of a colliery, three main considerations 
are to be taken into account: namely, safety, efficiency and 
economy ; and it is essential that all three conditions should be 
satisfied by the best form of guide for deep shafts. The first 
two naturally go together : for, in most instances, where almost 
perfect safety has been realized, the standard of efficiency has 
been as high. Therefore, when undertaking any kind of work 
wherein the safety of either men ot- animals is aifected, these two 
conditions must always be maintained, even in the face of 
economy if necessary. But economical working can generally 
be realized without loss of either safety or efficiency, if proper 
means are used. 

In order to discuss this particular question in an easy and 
simple manner, the best plan will be to take a practical example 
such as the following : — It is desired to wind 2,000 tons from a 
depth of 2,400 feet in 8 hours. All other considerations, such as 
the size of shafts, etc., are left to the discretion of the engineer. 

This big tonnage will undoubtedly necessitate the sinking of 
a shaft of large diameter. Let it be supposed that a shaft, 
about 18 or 20 feet in diameter, will be reqiiired, varying in size 
according to the kind of conductor employed. Therefore the 
engineer is faced with the problem *' What is the most suitable 
form of guides for cages for .winding from a shaft 2,400 feet 

* Thifl student's prize essay is printed in the Transactions at the special 
request of the Council of the Midland Institute of Mining, Civil and Mechanical 
Engineers, 



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GUIDES FOR CAGES. 109 

deep ?" He has not many kinds to choose from, since there are 
only three distinct types of guides : (1) Wooden gnides, (2) steel 
guides, and (3) flexible rope guides. 

As each case has to be decided upon its own merits, they must 
be taken separately, and an approximate estimate formed of 
their coat and suitability. All oth^r details remain the same, 
except where the type of guide used requires a modification in 
the construction of the cage. The cage adopted is shown in 
figs. 1 and 2 (plate iii.). It will be seen that it is of modem 
construction, and made for carrying a oounterbalance-rope. The 
advantages of this device are now fully recognized, and will be 
considered later. 

II. — Wooden Gtjides. 

The first thing to be considered is the position of the guides 
with relation to the cage. The complete arrangement is shown 
in fig. 3 (plate iii.) with two guides. A, placed at each end of 
the cage, B, on account of its width. This arrangement makes 
it necessary to have extra, guides, C, at the surface and at the 
pit-bottom, because the shaft-guides must terminate before 
reaching the landings in order to clear the ends of the cage. 

The necessary amount of clearance between the cages, when 
rigid guides are used, is obviously small, since little or no oscilla- 
tion can take place. In practice it varies from 3 to 12 inches, 
and, in this case, the clearance is 9 inches. 

The cage-shoes, made of cast steel, are bolted to the ends 
of the cage, on the top and bottom hoops (fiflrs. 4 and 5, plate iii.). 

The method of fixing wooden conductors together and to the 
buntons is shown in figs. 6 and 7 (plate iii.). 

In order to ensure perfect safety with wooden guides, the 
timber used must be of the best quality, free from knots, of 
straight grain, and able to take up a large amount of lubricant 
to maintain smooth running. At the same time the cost must 
not be excessive. The timber which has satisfied all these con- 
ditions is pitchpine. If it is sawn and planed correctly with the 
grain, splintering, which has been the cause of some serious 
accidents, can be entirely avoided. 

The next consideration is the efiiciency of the wooden guide. 
A large number of mining engineers of repute have stated, no 



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110 GUIDES FOR CAGES. 

doubt correctly according to their own experience, that wooden 
guides only last from two to five years. But this period can be 
extended to at least 15 to 20 years if the guides are greased, 
thoroughly and regularly, every fortnight. 

With regard to economy, the following is an approximate 
estimate of the cost of fitting up a shaft, 18 feet in diameter 
and 2,400 feet deep, with conductors, etc., as shown in figs. 3, 4, 
5, 6 and 7 (plate iii.) : — 

£ 8. d. £ ft. d. 
AfatericUs : 

Buntons, 8,400 lineal feet at i^d. per foot 

Stays, 600 cubic feet at la. 3d. per cubic foot ... 

Conductors, 4,800 cubic feet at Is. 3d. per cubic foot 

10 per cent, for joining pieces 

Cast-iron boxes, 27 tons at £8 per ton 

Labour: 

Sawing, planing and fitting buntons, etc. 
Sawing, planing and fitting conductors 



Total 



III. — Steel-eail Guides. 

Steel-rail guides are largely used on the Continent, but in 
this country they have not found quite so much favour. If 
steel-rail guides were used in the shaft already mentioned, the 
following arrangement might be adopted : Four rail guides, A, 
weighing 20 pounds per foot, placed, two at either side of the 
cage, B. In the middle, they are clamped to steel joists, C, 
and at the sides to cast-iron sleepers, D, bolted to wooden 
buntons, E. The vertical distance between the centre of the 
joists or of the buntons is 10 feet; and the rails, forming the 
guides, are in lengths of 30 feet. This is the only arrangement 
permissible, since rail guides are not suitable for fixing at the 
ends of the cage. The arrangement is shown in figs. 8, 9, 10, 
11, 12, 13, 14 and 15 (plate iii.). 

This type of guide lasts about fifteen years; but, in some 
cases, it has been known to fail at the web in a shorter time, 
owing to the wear of the shoes at this iwint. 

The approximate cost for fitting a shaft, 18 feet in diameter 
and 2,400 feet deep, is as follows : — 



148 15 











37 10 











300 











48 











216 





760 


R 





250 





O 


V 


400 





650 














... 


£1,400 


5 






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111 j 


£ 8. 


d. £ s. d. I 


1,028 8 


i 


93 12 





25 
27 
58 





1 232 


500 
400 




900 








£2,132 



GUIDES FOE CAGES. 

MaleridU: 

Rails, 171 '4 tons at £6 per ton 

Joists, 8 inches by 3 inches, 15*6 tons at £6 per 

ton 

Wooden buntons, 6 inches square, 400 cubic feet 

at Is. 3d. per cubic foot 

Cast-iron sleepers, 3 tons at £9 per ton 

5 per cent, for waste 

Labour : 

Cutting and fitting joists, buntons, etc. 
Fitting conductors 

Total ... 



IV. — Rope Guides. 

This system is very popular amongst British mining engineers. 
At first sight the cost appears to be very low, but this is by no 
means the case when everything is taken into account. 

Owing to the flexible nature of the guide there is a large 
amount of oscillation. This can be reduced to a minimum by 
usinif a tail rope under the cages; and, in some cases, this 
device has been found to be absolutely necessary to prevent 
bumping at meetings, even when curtain ropes are in use. But 
even with a tail rope, in a shaft 2,400 feet deep, at least 18 
inches of clearance between the cag^s, and 12 inches between 
the cages and the sides of the shaft must be allowed. This 
necessitates the sinking of a shaft 20 feet in diameter. The 
difference in cost for this larger shaft will be at least £1 per 
foot, which must be added to the cost of fitting rope guides. 

The advantages claimed for this system are: — (1) Easy 
fitting up and working; (2) freedom of expansion or contrac- 
tion; (3) a clear shaft; (4) lessened first cost; and (5) longer 
life than any other type of guide. The first three advantages 
are undoubtedly obtained, but the fourth is quite incorrect, as 
will be shown later. 

There is a great diversity of opinion with regard to the 
life of a rope guide. Instances are quoted where rope guides 
have lasted over 30 years. But they are the exception, and not 
the rule, as the writer discovered when making inquiries amongst 
enginewrights who had had the handling of them. They stated 
that 5 to 10 years was the average life of a rope guide. 



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112 GUIDES FOB CAGES. 

Figs. 16, 17, 18, 19, 20, 21 and 22 (plate lii.) show the details 
of the various arrangements. 

The estimated cost of fitting a shaft, 20 feet in diameter and 
2,400 feet deep, with rope guides, is as follows : — 

£ B. d. £ a. d. 
Materials : 

Ropes, 42-4 tons at €30 per ton 1,272 

Cast-iron weights, 24 tona at £8 per ton ... 192 



1,464 

Labour : 

Fitting guides, etc. 50 

Sinking : 

Extra cost of sinking at £1 per foot 2,400 



Total £3,914 



V. — Conclusions. 

As each system has now been considered, it only remains for 
the best to be selected. 

So far as safety is concerned, all three methods have been 
laid out in such a way that the maximum safety has been 
obtained in each case, so that it may be justly and correctly said 
that they are all as safe as it is possible for anything to be, and 
that no comparison can be formed on this point. 

The next point to be considered is the relative efficiency. 
Summed up as briefly as possible, the life of each system is as 
follows: — (1) Wooden guides, 15 to 20 years; (2) steel-rail 
guides, 15 to 20 years ; and (3) rope guides, 5 to 10 years. This 
shows that wooden or steel-rail guides are the most economical, 
so far as efficiency is concerned. 

The relative costs are as follow: — (1) "Wooden guides, 
£1,400 ; (2) steel-rail guides, £2,132 ; and (3) rope guides, £3,914. 
From these figures it is proved that wooden guides are by far 
the most economical. 

Therefore, according to the general principle of analysis, as 
regards safety, all three systems are equal in merit; as regards 
efficiency, wooden or steel-rail guides excel; and wooden 
guides are the cheapest. So that, to sum up the situation in a 
few words, pitchpine guides are, by reason of their safety, 
efficiency and economy, '' the most suitable form of guides for 
cages for winding from deep shafts : 1,500 feet and deeper." 



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I 

'lies for Cag es /orMndm^n^ 



voLXxxm^BLATEm. 

?^iQ. 8,-Plan of Shaft. 18 Fe^"^'-^'^ ^^ Cage-shoe Fig. 14.— Elevation of 

FITTED WITH SteEL-RAIlP'^^^L-BAIL GUIDES. STEEL-RAIL QuIDE. 




\ 



AA 



\, 



B 



:r. 



A 

\ 




'm 



ilevation of Cage-shoe 
$teel-rail Guides. 



rz: 



t 




D 



Fig. IS.-Plan of 
Steel-rail Guide. 
/« J 



«4 



Elevation Fiq. 12.-Elevation of 
Guides, of Steel-rail Guides. 




Fig. 20.— Ele 
Clamped Enc 
Guide in He^ 




im* 



i 



r - 






T 



Scale, 2 Feet t o 7 inch. 



Hi 



Fig. 22— Elevation of 

Weighted End of 

Rope Guide in Sump. 



Fiq. IS.-Sectional Plan 
ON Line YZ of Fig. 12. 



Fig. 21.-f 
Clamped En 
Guide in H 





Fio. 19.— Section of 
Caqe-shoe for Rope Guides. 



et to 7 /nch. 





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yoLX]Tn.,PLATEn. 



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DISCUSSION — GUIDES FOR CAGES. 



118' 



Mr. Heebert Perkin (Leeds) wrote that, in dealing with the 
construction of rope guides, Mr. Routledge did not mention the 
wellknown locked-coil guide rope, which seemed to be the most 
suitable as presenting a perfectly uniform wearing surface. A 
good form of clamp (figs. 23 and 24) was in use at the Shelton Coal 
and Iron Company, Limited's deep pit at Hanley, where rope 
guides were in use in a shaft 2,550 feet deep. It consisted of a 
rectangular block-forgin-g in which a slot was cut, and two 
wedges, gripping the rope, were fitted into the slot. Above this, 
with a slight gap in between, two or three clamps of the ordinary 
bolted type were fixed on the rope, the gap being used to indicate 
whether any slip was taking place. In the sump, the method of 
attaching the weights was simply the reverse of the arrangement 
used in the headgear. This method had been found eminently satis-, 
factory. With regard to the weights hung upon the conductors, 




rm fr"n 




4 N 



Fig. 23.— Side Elevation 
OF Clamp. 



Fig. 24.— Plan of Clamp. 
Scale, 1 Foot to 1 Inch. 



the limit, of course, was reached when fui-ther increase would 
dangerously lower the factor of safety : this should not be below 
5, that was, the attached weights together with the weight of 
the hanging rope should not be more than one-fifth of the brejak- 
ing load. The clearance of 18 inches between the cage-comers and 
the shaft-wall was certainly most important, because of the possi- 
bility of a bulging of the shaft taking place, and 15 inches 
between the centre guides were ample. 

He (Mr. Per kin) could not a^ree with Mr. Kennedy's con- 
clusions that wooden guides were either as safe, as efficient, 
or as economical as rope guides for great depths. It seemed a 
very dangerous plan to fill a downcast shaft with timber, 
especially if electric cables were taken down the pit. The bolted 
joints were also a source of danger. Mr. Kennedy's addition of 



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114 DISCUSSION — GUIDES FOR CAGES. 

£1 per foot for the extra cost of siakiiig a shaft, 20 feet in 
diameter instead of 18 feet, overlooked the important fact of the 
largely increased area obtained. It was probable that in a shaft, 
18 feet in diameter, fitted with wooden guides, the effective 
area would be reduced by 8 or 10 per cent., owing to buntons. 
For equal quantities of air, therefore, there would be a very 
considerable saving in the power required for ventilation in 
the case of a shaft 20 feet in diameter. If non-twisting ropes 
were used there would be very little oscillation, and the addi- 
tion of a tail rope was a profitable investment, apart altogether 
from any steadying qualities that it might have. The great 
disadvantage of rigid guides was their liability to cause extra 
friction by being thrown out of plumb if there was a slight 
movement of the shaft. 

Mr. M. H. Habershon said that members, who had experi- 
ence of winding large quantities of coal with wooden guides, 
would agree that the cost of repairing was excessive, and that 
the conclusion at which Mr. Kennedy arrived as to their economy 
was not correct. 

Mr. W. Walker (H.M. Inspector of Mines) said that it 
appeared from Mr. Boutledge's paper, that he had taken as a 
minimum a shaft 20 feet in diameter for wire-rope guides ; but 
in the case of South Kirkby ooUiery the shaft was only 15 feet in 
diameter, and the clearance between the cages at meetings was 
as little as 6 or 8 inches. The shaft was 2,130 feet deep, and the 
weight at the bottom was much in excess of the figures given by 
Mr. Boutledge. This weight was a serious consideration so far 
as the headgear was concerned, but the running was even, and 
there was no difficulty in any other way. He thought that the 
distance given between the buntons in both papers was too great, 
as an accident had occurred from this cause in his mines- inspec- 
tion district last year with rail guides. One of the rails broke, 
and the cage became free and collided with the descending cage 
at meetings. He could not agree with Mr. Kennedy's conclu- 
sions that wooden guides were the safest or even the most 
economical. Taking the speed at which the cages ran at Cadeby 
colliery, about 72 feet per second, when men were being raised 
or lowered, he should not like to be in the cage if the guides were 
made of wood. The shoes used in connection with rail guides 



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DISCUSSION — GUIDES FOR CAGES. 115 

were better and safer if they extended over tke full length of the 
cage, as at Cadeby colliery ; and, if a rail broke, there was not 
then SO much chance of the cage getting out of the guides. 

Mr. J. J. Eley said that he was, at the present time, substitut- 
ing rope guides for wooden guides, and the cost of maintenance 
and repairs of wooden guides was very high in comparison with 
wire-rope conductors. 

Mr. A. T. Thomson said that he had experience of three kinds 
of guides. Wooden guides were a source of continual expense, 
as some lengths were always being changed ; he had some wire- 
rope guides which had been in use for thirty-three years, and they 
were still in splendid condition; and he had had a rather un- 
pleasant experience with rail guides. He much preferred the use 
of wire-rope guides. 

Mr. H. Rhodes said that, over a period of thirteen years, the 
number of stoppages ai six shafts, fitted with wire-rope con- 
ductors and varying in depth from 1,200 to 1,800 feet, was con- 
siderably lees than at a similar number of shafts, fitted with 
wooden conductors and varying in depth from 360 to 1,200 feet. 

Mr. R, PuRDY said that he could not agree with Mr. Kennedy 
that wooden conductors were either ihe best or even the cheapest. 
He knew a shaft, over 1,800 feet deep, where wooden conductors, 
7 inches by 5 inches, were in use. As they were occasionally 
broken and caused stoppages and damage, they were replaced by 
wire guides ; and the alteration proved a great advantage, and 
soon paid for the cost of changing. He thought that Mr. 
Kennedy's estimate of Is. 3d. per cubic foot was very low for 
pitchpine suitable for conductors, and he (Mr. Purdy) was paying 
nearly 2s. per cubic foot. 

Mr. Routledge referred to vibration or sway, regarding which 
he (Mr. Purdy) thought that the whip or swing of guide-ropes in 
a shaft was not so much the fault of the guides as of the cage not 
being properly level and balanced at the commencement. Wind- 
ing a cage, 9 or 11 feet long, 4 feet wide and 12 or 15 feet high, 
was like trying to balance a brick on its edge. If the cage were 
lifted 6 inches at one end before being raised at the other, the 
whip set up in the winding-rope would be transmitted to the 
guide ropes and the cage would be in danger of striking the shaft- 
sides or of coming into contact with the opposite ca^e when pass- 



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116 DISCUSSION — GUIDES FOR CAGES. 

ing. To prevent this whip, the four carrying chains should be 
fitted with left-hand and right-hand screws, and the cage should 
he hung in perfect balance from each corner. The props at the 
surface and the buffers at the bottom should be made perfectly 
level to receive the cage, so that when it was raised by the wind- 
ing-engine, there should be no tilting motion at the comencement. 
If the balance and levelling wore properly attended to, the risk 
of accidents would be materially reduced. 

Mr. H. Baddelky said that in the case of two shafts in 
North Staffordshire the use of a balance-rope had considerably 
reduced the oscillation of tie cages. Each shaft was over 2,400 
feet deep, one shaft being 14 feet in diameter for some depth, and 
it was then belled out to 20 feet in diameter. A flat balance-rope 
was used in both cases, and the oscillations, as stated before, were 
very little ; and, although there was not a great space between 
the cages and the shaft-sides, everything seemed to work satis- 
factorily. The use of a flat balance-rope was somewhat of a 
novelty to him (Mr. Baddeley) and he was interested with the 
satisfactory way in which it was working. No pulley or casing 
was required in the pit-bottom, and the rope simply formed a 
curve below the sump-boards. He observed that the estimated cost 
given by Mr. Kennedy for pitchpine wasstoo low, and that he 
would like to sell wire-rope guides at the prices named in Mr. 
Kennedy's estimate. 

Mr. C. H. Elliott (Wombwell Main colliery) said that the 
winding shaft at Wombwell Main colliery was 1,500 feet deep, 
the upper 660 feet being llj feet, and the remainder 13^ feet, 
in diameter. Six corves were carried on three decks ; the wind- 
ing-ropes were locked-coil, lyV inches in diameter ; and the cages 
were provided with a balance-rope, which passed round a pulley 
in the sump. Formerly, each cage ran on four wire-rope guides, 
li inches in diameter, two guides being placed at either side, near 
the corners of the cages. This arrangement gave a clearance of 
12 inches, but the cages caught the sides occasionally, when in 
the smaller portion of the shaft. This difficulty had been success- 
fully overcome by suspending two separating guides, each 2 
inches in diameter, down the centre of the shaft, bringing the 
cages close up to them, and at the same time adopting three 
guides, all placed at the outer sides of the cages, for the four 



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DISCUSSIOX — GUIDES FOR CAGES. 117 

which were formerly placed near each comer. Each cage was 
fitted with a rubbin-g^ piece of soft steel, which could be changed 
when worn out. This arrangement had now been at work for 
seven years without the slightest hitch, and the cage ran very 
smoothly. The output was 1,500 tons in 10 hours, a draw being 
made in 50 seconds, with an average cage-speed of 30 feet per 
second. 

Mr. G. A. LoNGDEN (Pleasley) wrote that the two shafts at 
Pleasley colliery, sunk to the Top Hard coal-seam in 1877, were 
14i feet in diameter and 1,560 feet deep. The downcast-shaft 
only was fitted with wooden guides; and, in 1888, the double- 
decked cages, with two trams on each deck, were winding to 
their full capacity. In order to obtain ^n increased quantity of 
coal, the upcast-shaft was fitted up in 1888 with cages holding 
one tram on a deck: at first two-decked and later three-decked 
cages were used, decking at the pit-top and the pit-bottom. 
This arrangement sufficed for eleven years ; and, in 1899, it was 
decided to erect a new winding-engine, headgear and boilers to 
work at a pressure of 100 pounds per square inch, and to fit 
cages in the upcast-shaft similar to those used in the downcast- 
shaft with simultaneous changing of the decks. 

Rope Guides. — The question of conductors at the upcast-shaft 
was carefully considered, and iron-rope guides were adopted as 
being the safest and cheapest, with less friction in the shaft both 
for the cages and for the ventilation, which must not be over- 
looked in small shafts, 14^ feet in diameter. There were two loose 
rope guides, 2 inches in diameter between the cages; oaken 
rubbers were bolted to the cages to prevent them from touching 
the guides; and there were three fixed guides, 1^ inches in 
diameter, fitted on the outside of each cage. Ordinaiy winding- 
ropes and two kinds of non-spinning ropes were not found satis- 
factory, as they twisted the cages in the centre of the shaft, where 
the guides were not stiff enough to keep them in position ; and 
finally locked-ooil winding-ropes were adopted. The cages now 
hung square at meetings, and hardly ever touched the two loose 
central guides. Locked-coil winding-ropes were more expensive 
than those used with wooden guides, and this extra cost must 
be added. If the treads of the pulleys were true and locked-coil 
winding-ropes were used, there was veiy little swaying of the 



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118 DISCUSSION — GUIDES FOB CAGES. 

cages, and they could be run close to the central rubbing guides. 
The initial cost of the rope guides is detailed in Table I. The wet 

Table I.— Cost of Rope Guides at Pleasley Coluebt. 

Six rope guides, 1} inches in diameter, at £50 each 300 

Two „ 2 „ „ „ , „ £85 „ 170 

Cast-iron weights, 30 tons at £4 lOs. ... 135 

Labour of fixing 30 



Total £635 



state of the upcast-shaft makes the rope guides wear rapidly, 
and they only last about five years ; but the two rubber guides 
last longer. Allowing £80 per annum for renewals and 
£50 per annum for the enhanced cost of the special winding- 
ropes over and above the cost of the ropes used in the downcast- 
shaft, the total cost becomes £130 per annum. 

Wooden Guides. — The downcaat-shaft is fitted with wall-boxes 
to receive a centre stay and two side stays at intervals of 10 feet. 
There are about 300 feet of cast-iron tubbing, with brackets cast 
on the plates. There are eight guides, measuring 4| inches by 
4J inches, two being fitted on each side of each cage. The cost 
of installing the ^wooden guides is detailed in Table II. 

Table II. — Cost op Wooden Guides at Pleaslet Colliert. 

£ 8. d. 
159 central stays of oak, 16^ feet long, 8 inches wide and 9 

inches deep, at £1 9s. each 230 11 

318 side stays of oak, 13 feet long, 6 inches wide and 9 

inches deep, at 17s. each 270 6 

Cast-iron wall-boxes, two large ones and four small ones, 

say, 5 cwts. every 10 feet, 40 tons at £8 per ton ... 320 

Eight pitchpine conductors, 1,580 feet long or 12,640 feet at 

7 'Sid. per foot, the average price over 8 years ... 

Wooden jointing of conductors 

Pins for the conductors, 30 cwts. at 13s. 6d. per cwt. 
Labour of fixing : this does not include the cost of fixing 

the wall-boxes 

Total 



The annual cost of maintenance has been as follows : — The oaken 
stays gave little trouble for twenty years, but since that period 
several of them have been replaced, and, allowing 5 per cent, per 
annum on £500, the cost has been £25 ; the actual average cost 



411 


6 


6 


50 








20 


5 





420 








£1,722 


8 


6 



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DISCUSSION GUIDES FOR CAGES. 119 

of pitchpine conductors over the past eight years has been £60 ; 
labour, refixing, renewing pins, etc., 60 shifts at 27s. per shift, 
£81 ; add the loss of three breakages per annum at li hours each, 
or 4i hours' standing at 120 tons per hour, or 540 tons at Is. per 
ton, £27 ; and the total is £193. The shaft contains about 300 
feet of cast-iron tubbing, with bi'ackets cast on the plates to 
receive the wooden stays, so that it would be impossible to adopt 
two wooden stays with end-guides to the cages, even if it were 
desirable to do so. 

It will be seen from the preceding figures that the first cost of 
the rope guides at the upcast-shaft was rather more than one- 
third of the cost of the wooden guides at the downcast-shaft, 
whilst the annual maintenance for ropes is £130 as compared with 
£193 for wood. The annual charge of £130 for the maintenance of 
the rope guides is considered very high, but it is due to the short 
life of the guides ; and, if they had been placed in the downcast- 
shaft, their life could be easily doubled. Rope guides used in 
a dry shaft will last from twelve to fifteen years. Wooden 
guides are found to wear most rapidly at the place where the 
engineman begins to steady the cages. Oregon pine had been tried, 
but it had been replaced by pitchpine. It must not be over- 
looked that three months were occupied in fixing the wooden 
guides, working three shifts of eight hours for seven days a week, 
while the ropes, guides and cages were fitted in a week; and, 
at Pleasley colliery, the fitting of the upcast-shaft with wooden 
guides would have meant the loss of thousands of tons of coal. 



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120 DISCUSSION — SINKING AND TUBBING. 



THE MIDLAND COUNTIES INSTITUTION OF ENGIN- 
EERS AND MIDLAND INSTITUTE OF MINING, 
CIVIL AND MECHANICAL ENGINEERS. 



JOINT GENERAL MEETING, 
Hbld at Chestebfikld, Mabch 9th, 1907. 



Mb. W. G. PHILLIPS, in the Chaib. 



The Secretary announced the election of the following 
gentlemen to The Midland Counties Institution of Engineers : — 

Mkmbebs — 
Mr. E. J. H. Christie, Electrical Engineer, Bank Chambers, Fargate, 

Sheffield. 
Mr. Thomas Pebct Nicholson, Mining Engineer, Hillcrest, Shepherdswell, 

near Dover. ^ 

Mr. John SMrrnintST, Manager, West Cannock Collieries, West Cannock 

House, Hednesford, Staffordshire. 

Students— 
Mr. Chables Gates, Student, Kirkby Road, Sutton-in-Ashfield. 
Mr. Qeoboe Patrick Littlswood, Student, Blackwell, Alfreton. 



DISCUSSION OF MR. I. HODGES* PAPER ON "AN 
ACCOUNT OF SINKING AND TUBBING AT METH- 
LEY JUNCTION COLLIERY, WITH A DESCRIPTION 
OF A CAST-IRON DAM TO RESIST AN OUTBURST 
OF WATER.'** 

Mr. G. Elmsley Coke (Nottingham) said that he knew the 
Whitwood collieries, but had not seen that shaft since the re- 
tubbing. The shaft was sunk on a large fault which crossed the 
measures, and ran through the canal, causing large feeders of 
water. Mr. Hodges had the very difficult problem of making 
the shaft watertight and secure, and he appeared to have solved 
it with skill and success. The tubbing might now be expected 
to endure for the extended life of the mine. 

* Trans, Inst. M. E,, 1906, vol. xxxii., page 76. 



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DISCUSSION — SINKING AND TUBBING. 1^1 

Mr. H. R. Hewitt said that the work undertaken by Mr. 
Hodges appeared to have only just been in time to avoid the 
collapse of these shafts, and was a suggestion to those having old 
shafts in use to examine their tubbing and ascertain the thick- 
ness of the plates from time to time. In deciding upon a new 
centre-line, the thickness of the new tubbing-plates prohibited 
the centre-line from being moved far, as the author did not appear 
to have taken any of the old tubbing out of the shaft. It 
appeared strange that the work of putting a dam in the upcast 
shaft was not done some years earlier when the water was found 
to be troublesome, as the cost was so insignificant compared with 
the annual charges dispensed with. It was well known that 
f ormulsB for ascertaining the thickness of tubbing required gave 
a variable result, and when these were placed side by side in 
Table VI.* it would appear that the one given by Mr. W. 
Galloway should in future be dispensed with as being altogether 
misleading, and no harm could be done by erring on the side of 
safety in a matter of this kind. When so wide a difference as 
0*05 inch to 0'50 inch was given for the thickness of tubbing 
at the same depth, there was a great error somewhere, and yet 
the author* of the paper used a thickness of 0*75 inch for the 
same depth m these shafts. It would be interesting to know 
what formula he adopted for this, and why he considered such a 
thickness necessary at a depth of 60 feet, for which, taking this as 
his standard, the extra cost involved must have been very great. 
Although shaft-work of a dangerous nature was frequently being 
done, it was gratifying to notice that the number of accidents 
was so few, and this was a creditable record of the skill and fore- 
sight displayed by Mr. Hodges and his officials. 

Mr. Isaac Hodges, replying to the questions asked by Mr. J. S. 
Bamest at the last meeting, thought that he had made it clear 
in his paper that the upper length of tubbing, 260 feet, stood on 
one foundation crib only, the total weight on that crib being 286 
tons. He agreed that this was a heavy weight for one crib; 
but it was, quite impossible to make an atta>chment to the old 
tubbing, nor was it desirable, as it was in so shaky a condition 
as to be scarcely able to stand the pressure which it already had to 
bear. Mr. Barnes said that he disliked cribs being spaced at greater 

♦ TroM, Inst, if. S., 1906, vol. xxxii., page 96. t Ibid,, page 98, 



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128 DISCUSSION — SINKING AND TUBBING. 

distances apart than 60 feet. There was something to be said for 
cribs being spaced at frequent intervals, but, at Methley Junc- 
tion colliery it was impossible to do otherwise than stand the 
whole length of the new tubbing upon the foundation-crib below 
the old tubbing. Mr. Barnes had asked how the horizontal and 
vertical sheathings were inserted. The tubbing was built in 
rings at the surface by means of a turntable on the drawbridge, 
and the vertical sheathing was placed in position at the time when 
the rings were being built up. A ring of tubbing was run over 
the pit, lifted, the drawbridge withdrawn, and the ring of tub- 
bing lowered into position. The workmen followed afterwards 
in a kibble, saw the ring of tubbing placed in position, and 
then laid the horizontal sheathing for the next ring before 
returning to the surface. It was by that means that they were 
able to complete and put into position a ring of tubbing every 
40 minutes ; and, by working 24 hours per day, the upper section 
of 140 feet was completed and placed in position in less than 
two days. Eeferring to the remarks as to coating, he thought 
that Dr. Angus Smith's composition was a great safeguard 
against corrosion. The original tubbing had been partly 
destroyed by internal corrosion, and he thought that the use of 
composition on the new tubbing would tend to remedy that evil. 
The casting of figures in relief on the face of each segment of 
tubbing indicating the thickne*ss would enable his successors to 
test the then thickness, and so form an accurate judgment as to 
the deterioration. It was difficult to refer to old figures and 
plans, perhaps a quarter of a century old ; and it seemed to him 
that there was greater safety in having the figures cast on the 
tubbing, and knowing that those figures indicated the original 
thickness. Tests would then either give them a sense of security, 
or prompt them to take speedy measures to remedy the defect. 
Since the paper was written, the slight leakage past the plug of 
the second pipe had diminished until it was now quite dry. It 
would be remembered that, when the dam was completed, about 
100 gallons of water passed per hour; within a fortnight this 
quantity was reduced to 26 gallons per hour, and it further gradu- 
ally reduced to 9 gallons per hour. The shaft was now quite dry, 
and no sign of water had shown itself in the workings. A saving 
of upwards of £1,300 per annum in pumping had been accom- 
plished by an expenditure of £1,590 on the dam- 



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DISCUSSION — SINKING AND TTTBBING. 123 

In calculating the strength of tubbing required to resist the 
pressure of wat^r, he had occasion to take from various text-books 
the thickness of tubbing as worked out by Messrs. J. J. Atkinson, 
W. Galloway, G. C. Greenwell and W. Tate. He was much struck 
by their divergence, and it occurred to him that it might be of 
benefit to have these formulae put side by side for comparison. He 
then compared the tested thicknesses of the old tubbing with the 
patterns from which the tubbing had been cast in their own 
foundry about 1850, and at once he saw that the half-century's 
usage had resulted in serious deterioration, in quality quite as 
much as in thickness. Therefore he came to the conclusion that 
the formula generally adopted was inefficient, and needed revision. 
The thicknesses of tubbing given in Table VI.* showed, so far 
as shallow depths were concerned, that they were much too light. 
In his case, tubbing IJ inches thick had diminished in thick- 
ness to yV iiich after a usage of about half a century, and he had 
therefore worked out a formula including a constant allowing 
for corrosion and wear-and-t«ar. Although the formula might 
perhaps he criticized as giving an unusually heavy thickness, 
that was a fault which mining engineers would agree was not a 
particularly grave offence. The dangers from weak tubbing were 
serious and out of all proportion to the saving made in the original 
capital expenditure. The formula that he had used was: — 



LB I.— Thicknesses 


OF Tubbing Calculated by the 


PR 
Formula : T = -^ + C, 


TOOETHEB WFTH THE ACTUAL THICKNESSES USED IN 


the Methley Junction 


Shatts. 






Height 
of Tubbing. 


ThicknesseB of Tubbing 
calculated from the above Formula. 

I. —Shaft: 10 Fett in Diameter, 


Thickneflses of Tubbing 

actiully uiie<l in Methley 

Junction Shafts. 


Feet. 


Inches. 


Inches. 


60 


0-69 


0-75 


100 


0-82 


0-87 


140 


0-95 


100 


ISO 


1-08 


1-12 


220 


1-21 


1-25 


260 


1-34 

IL— Shaft: 11 Feet in Diameter, 


1-37 


WO 


1-45 


1-50 


340 


1-59 


1-62 


3S0 


1-74 


1-76 


420 


1-88 


1-87 



* Trans. Inat. M. E,, 1906, vol. xxxii., page 96. 

TOL. XXXI1I.~1906-1907. 



10 



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124 DISCUSSION — THE C0URRi4rES EXPLOSION. 

T=(PR/S) + C ; in which P is the pressure in pounds per square 
inch; R, the internal radius of the tubbing in inches; T, the 
thickness of the tubbing in inches ; S, the safe stress of cast-iron 
or 8,000 pounds per square inch; and C, a constant providing 
for corrosion and wear-and-tear, namely : — i inch for depths not 
exceeding 300 feet, | inch for depths exceeding 300 feet but not 
exceeding 600 feet, and J inch for depths exceeding 600 feet. 
The actual thicknesses of tubbing used in the Methley Junction 
shafts, as compared with the thicknesses calculated from the 
above formula, were recorded in Table I. 

The Chairman (Mr. W. G. Phillips) thought that members 
might refer to Mr. Hodges' paper as an interesting account of 
overcoming extraordinary difficulties in a masterly manner. 
They were indebted to Mr. Hodges for the trouble that he had 
taken in compiling his paper and supplying drawings of minute 
correctness, which materially helped to the understanding of the 
paper. 

The further discussion was adjourned. 



DISCUSSION OF MESSRS. W. N. ATKIXSON AND 
A. M. HENSHAW'S PAPER ON " THE COTJRRIERES 
EXPLOSION."* 

Mr. W. N. Atkinson (H.M. Inspector of Mines) wrote that 
Mr. A. H. Stokes referred to the advantages, from the point of 
view of safety from explosions, of having the districts of a mine 
so split up by ventilation that any catastrophe which occurred 
would so far as possible be isolated. Whilst, however, the panel 
system was an excellent one for several reasons, it had been 
proved over and over again that it was of no avail for arresting 
an explosion in a dusty pit, when the roads connecting the 
different districts contained inflammable dust. Where in dusty 
pits, such as those in which large explosions invariably occurred, 
certain ventilating districts had escaped the effects of the explo- 
sion, the reason was found, not in the fact that they were separ- 
ately ventilated, but because there was a break in the train of 
dust or a change in the nature of the dust. 

• Tran8. InU, M, K, 1906, voL xxxiL, pages 439, 340 and 507. 



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DISCUSSION — ^THE COURRliEES EXPLOSION. 126 

With reference to the shot in the LecoBuvre heading, and the 
fact that it was not known to any oflficial that it was a shot which 
had missed fire, the officials most likely to have known were 
killed, and as the miners fired their own shots it waa quite possible 
that no official knew anything about it. The heading was not a 
new clean heading: it was an exceedingly dusty place, the 
dust, as stated in the paper, being chiefly due to the use of a 
percussive heading-machine. 

With i-eference to the initiation of the explosion, whilst it 
was practically certain that it occurred in the Lecoeuvre heading, 
there was still room for some argument as to the exact means. 
The suggestion made by Mr. Stokes as to the possibility of an ex- 
plosion of Favier-powder while being handled was not overlooked ; 
but to the writers (Messrs. Atkinson and Henshaw) the balance of 
probabilities appeared to be strongly in favour of the theory set 
forth in their paper. The cutting above and down to the shot-hole 
(fig. 20)* appeared to have no other object than to enable the 
explosive to be reached. The most difficult thing to account for 
satisfactorily was the dismemberment of the body of the fourth 
man, which was found about 60 feet from the face. Perhaps this 
man was nearer the face at the moment of the explosion, and in 
the line of the shot, and was blown and dismembered by the shot 
blowing out. The damage to the air-pipes did not appear so 
difficult to account for. Such pipes were sometimes made of 
inferior metal, and, if rusted and worn, required no great force to 
shatter them. 

The shot in No. 1 experiment, at Frameries, was not fired 
under conditions similar to those that attended the shot in the 
Lecoeuvre heading. In the former case, there was neither gas 
nor dust in the experimental gallery, whilst in the Lecoeuvre 
heading there was an abundance of dust. 

Mr. G. A. Lewis (Derby) said that he wished chiefly to draw 
the attention of the members to certain remarks made by Mr. A. H. 
Stoke8,t which it was possible, unless they had carefully read 
the Transactions J might have escaped their notice. The great 
point about this explosion was its origin, and he thought that it 
was a matter of extreme surprise to many mining engineers in this 

• Trans, Inst, M, F., 1906, voU xxxii., page 471. 
t Ibid., page 340. 



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126 DISCUSSION — THE COITBRliSRES EXPLOSION. 

country that engineers who had inspected the collieries agreed 
that the explosion was started in a heading. It was a coal-dust 
explosion, and it was practically unanimously decided that there 
was no gas whatever in the pit. The question then was, how 
could a coal-dust explosion be started in a heading, which could 
hardly contain dust of such a quality as would, judging by their 
experience in this country, be liable to start such an explosion ? 
If the blown-out shot, which was supposed to have started the 
explosion, did really fire the coal-dust, the flame would have 
had to travel 45 feet before it reached any dust. That was a 
position which most of the members failed to comprehend. 
Another point which seemed to have escaped the notice of many 
of the members was that, whilst four men were killed in that 
heading, the three men who were at the far end of the heading 
were practically not injured at all, except by bums; but the 
man who was most seriously injured (in fact he had a leg and an 
arm blown off) was 30 or 40 feet, or even more, down the heading. 
He thought that the construction which Mr. Stokes placed upon 
that, and th.e explanation that he suggested, were extremely 
reasonable, and such as he (Mr. Lewis) would be inclined to accept 
without reservation. Mr. Stokes suggested that a shot was put 
in at the end of the heading, that it mis-fired — ^not that it was 
blown out — ^and that the material for the shot had been recovered 
out of the hole. There were indications confirming the belief 
that the hole had been dug out, and the explosive extracted, and 
it was suggested that it had been taken by one of the men some 
distance down the heading. Possibly he had placed it on one of 
the air-pipes and was try^ing to extract the detonator from the 
explosive, or some mishap occurred by which he caused a detona^ 
tion, and it exploded the material that he had brought with him. 
The dust at this point would be more liable to explode, and this 
theory would explain various otherwise puzzling phenomena. 
These conclusions, to his (Mr. Lewis') mind, accounted for the 
fact that the greater force of the explosion was to be seen 45 feet 
down the heading, and that the men at the end of the heading 
were not affected so much. Another point which gave plausi- 
bility to this hypothesis was the fact that the air-pipes close to the 
end of the heading were hardly damaged, while the third or 
fourth lengths of air-pipe from thje face of the heading were 
smashed to atoms. He thought that theory was extremely 



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DISCUSSION — THE COUBRIERES EXPLOSION. 127 

plausible, and it would go a long way to satisfy their doubts 
as to why an explosion should take place in a heading, whilst 
at the same time affording some idea as to the precautions 
which should be taken in driving such a heading. The main 
point seemed to be whether such explosions could not be stopped 
entirely. It rather occurred to him (Mr. Lewis) whether those 
of the members who were trying to solve the problem of prevent- 
ing the spread of an explosion were not proceeding somewhat 
in a wrong direction, and whether they should not direct their 
attention to the question whether these explosions could not be 
prevented altogether. By that he meant, was it not possible to 
limit the shot-firing apart from the coal-face to the period when 
the men were out of the mine ? It was a point to which he was 
trying to devote his attention, and he was convinced that it was 
better to do that than merely to endeavour to limit the spread of 
an explosion, and to restrict the area which it affected when it 
did occur. 

Mr. H. Stevenson (Linby) remarked that the dust in the 
heading, boot-top deep, consisted of fine coal made by a Sullivan 
percussive holing-machine. There was nothing in the mines of 
this country to compare with the dust in the Courrieres mines. 
When down the latter he noticed that the seams were contorted 
and twisted, and that the coal was peculiarly soft. It could 
be knocked off or even scratched down by the hand, and was very 
like black-lead. The amount of dust made was in excess of any- 
thing found in this country. 

Mr. J. T. Todd (Blackwell) said that there were one or two 
matters, which he found a difficulty in following. He did not 
think that there were any details which would tell the members, 
whether, if this fire occurred in the return-airway, how or why 
it occurred; or whether it was impossible to have occurred in 
any other part; nor had they anything to tell them what was 
the character of the coal-dust at Courrieres, or an analysis of it; 
or whether that coal-dust was totally different from any that they 
found in the mines of this country. He regarded it as an exceed- 
ingly open question whether this explosion ever occurred in a 
heading, or whether it did not originate from gas from some other 
part. Of course, given an explosion, if there were fine coal-dust 
and plenty of it, that explosion would be extended. He certainly 



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128 DISCUSSION — THE COUBRliRES EXPLOSION. 

did not think tkat Uiey were in a position to judge definitely 
Whether the explosion at the Courrieres collieries occurred in a 
heading and from a shot. They had to assume an exceptionally 
big charge of explosive, and that several things were done 
which were illegitimate and in flagrant violation of regulations, 
before they could arrive at the conclusion that the explosion did 
occur in that particulai* place. The information was not calcu- 
lated to carry them to that conclusion. Before they could 
accept the strong statement that a similar disaster might occur 
in this country, they wanted to know something of the character 
of the coal-dust, the principle of ventilation, an analysis of the 
coal-dust, the temperature of the mines and the nature of the 
explosive which they were using. So far as he was aware, it was 
a fact, since the Explosives Order had been brought into opera- 
tion, that no explosion had occurre<l on a main haulage-road 
through the firing of a shot with any explosive which was now on 
the Permitted List of Explosives. He agreed with Mr. Lewis 
that, if they could find a safe explosive, and prevent flames from 
blown-out shots such as they used to have from gunpowder, they 
would, under conditions of watering and proper supervision, have 
gone far towards removing the dangers of explosions in main 
haulage-roads. If they looked at the explosions which had 
occurred in this country and had been attributed to coal-dust, 
they would see that none of them had gone into the face — ^they 
stopped at a certain point. That indicated that the great danger 
was on the main haulage-roads in which were accumulations of 
very fine dust; and, if they removed in any way that source of 
danger, they removed very largely all danger of a repetition in 
this country of such a disaster as that which had occurred at the 
Courrieres collieries. 

Mr. A. H. Stokes (H.M. Inspector of Mines) said that Mr. 
Lewis had given a good resume of what he had tried to emphasize 
at the last meeting. The best advice that he (Mr. Stokes) could 
give to Mr. Todd was to read the official reports of colliery explo- 
sions, and they might give him an answer to many of the ques- 
tions which he had put He confessed that many years ago he 
was rather sceptical about coal-dust explosions without fire-damp, 
but after the instances at Timsburj', Camerton, and the one, 
which came especially home to him, at Blackwell, he could have 



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DISCUSSION — ^THE COUBEIERES EXPLOSION. 129 

no doubt on the subject. With, regard to the stoppings being 
blown-out, ^uid the fire in the Courrieres collieries, it was recorded 
that the stoppings were blown inwards : whereas, it the explosion 
had occurred at the fire, they would expect to have found them 
blown outwards. As regarded the explosion starting in the head- 
ing, about which Mr. Todd appeared to have some doubt, could 
Mr. Todd tell them what was the cause of the fourth stir-pipe 
being shattered and torn into so great a number of pieces ? No 
one could tell why the man near that air-pipe was so mutilated, 
an arm and a leg being found 10 feet from the body and outbye, 
if the explosion did not take place at the fourth air-pipe. With 
regard to the blown-out shot, of which so much had been made, 
it had been recorded by the authors of the paper that *' similar 
holes have been observed before in these headings," and that ** a 
somewhat similar hole has been since found at the face of the 
parallel heading."* The point for consideration waa not so 
much the result of the explosion, but the best means of prevent- 
ing the recurrence of such explosions. They heard a great deal 
about watering: it was good in its way, but if they watered a 
road-way for 300 or 400 feet, and it stopped the spread of an 
explosion, did it stop the foul gases which had been generated 
by the explosion from coming out and killing the men ? Such 
gases would travel to the upcast shaft irrespective of the watered 
portion of the road-way — ^the explosion might not go all over the 
pit, but the foul gases would be uncontrolled in their travel when 
doors and stoppings were destroyed ; and it was the irrespirable 
atmosphere after an explosion that claimed the greatest loss of 
life. Then came the question : If watering was only one step to 
the complete cure, where were they to look for safety ? Let them 
try to put their finger upon it. He thought that Mr. Lewis went 
half-way towards it. Let them stop shot-firing on the road-ways 
during the working shift, and see whether every shot, except at 
the coal-faces, could not be fired at night-time or when the coal- 
tuming shift of men were out of the pit. He did not think that 
they could completely get rid of shot-firing at the coal-face ; but 
a working-face was quite different from the road-ways. In a road- 
way, they had an ever-increasing accumulation, day by day, of 
the finest dust ; whereas at the coal-face there was a continuous 
advance and exposure of clean-cut coal. The face did not stand 
and allow dust to accumulate, but moved forward ; and the face 
Trans, Inst, M. E,, 1906, vol. zxxii., page 474. 



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180 DISCITSSION — ^THE COTJERI^BES EXPLOSION. 

of to-day was not the face of to-morrow. There were no accumu- 
lations of dust at the face, like those in the road-ways. With 
regard to the limitation of an explosion, when it did start, had 
not the Courriferes disaster taught them the lesson that if they 
had six pits it would be advisable not to connect them together? 
Had it not taught them that in laying out their* mines they 
should, as much as was practically possible, have isolated districts 
from the main intake-airway to the upcast shaft? They all 
probably could call to mind explosions where many lives had been 
lost in one district, whereas men in another district had continued 
working without knowledge of an explosion having occurred in the 
mine. At the Wingate Grange explosion in October, 1906, "some 
of the miners [in another part] had to be warned to leave their 
work, and one was so little concerned that he fired a shot about 
.1 a.m., or more than an hour after the explosion."* They would 
do well to consider what lessons they could take from the 
Courriferes disaster. 

Mr. Isaac Hodges did not think that they ran anything like 
the same danger in existing mines in this country as in the 
French, Belgian or German coal-fields. There was a great deal of 
difference in the fineness and explosive character of the coal-dusts 
at the working-faces in those districts, as compared with the 
granular dust found at working-faces in Great Britain. He 
had visited one of the Belgian mines on the French border, not 
far distant from Courrieres, and in their deepest seam he was 
astonished at the amount of dust found at the working-face 
and on the I'oad-ways, but especially at the working-face. The 
strata were contorted, the coal was very friable, and at a 
depth of 3,000 feet only about 5 per cent, of coal passed over 
a round hole, 1 inch in diameter. The amount of dust was 
obvious by looking at the faces of the miners themselves ; they 
were very much blacker than the miners of Yorkshire, and in the 
deepest seams in that county nothing could be found to rival it. It 
reminded him of nothing so much as the appearance of men 
recovered after an explosion. The point to which he particularly 
addressed himself was that raised by Mr. Stokes, as to the inad- 

* Reports to H, M, Secretary of State for the Home Department on the 
Circumstances attending an Eocplosion which occurred at Wingate Orange CoHiery, 
Wingate f on the 14th October, 1906, by Mr. A. H. Ruegg, and Messrs. R. D. Bain 
and J. B. Atkinson, 1907 [Cd. 3379], page 23. 



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DISCUSSION — THE COTJBRIEBES EXPLOSION. 181: 

visability of connecting mines underground. Tliere were many 
cases in which large outputs were required from a single shaft, and 
extensive areas of coal must be connected to provide the necessary 
pit-room. Even if Mr. Stokes' views were carried out for the 
future, and mines were not allowed to be connected, how would 
he deal with those mines which were already connected ? In his 
own case, they had 8 square miles of surface-area connected 
underground. The economies of that arrangement had been very 
considerable ; and, although he would not say that anything could 
justify loss of life, economy certainly justified any small extra risk 
that there might be in connecting such mines. He agreed that 
districts should be isolated in some manner; but he did not agree 
with Mr. Stokes that districts should be isolated by leaving 
barriers of coal, or by being worked from disconnected pits. 
He would rather that more attention should be given to the best 
means of zoning a mine, so that if an explosion occurred in one 
district it could be prevented from travelling into another. They 
had had some object-lessons from coal-dust explosions ; and in his 
own case he had considered it advisable to separate districts from 
each other by non-dusty lengths of brickwork. This consisted 
generally of brick-walls with a concrete roof, as he found it 
easier and cheaper, and less obstructive to the ordinary work of 
the mine during erection, than building semicircular arches. 
He felt that the Courriferes disaster was sufficiently serious to 
make them attempt to do something, and by periodically 
cleaning those zones he hoped to do a little towards preventing 
an explosion from spreading. He did not know whether it 
would be necessary to water those zones, but they would learn 
more on that point during the course of the next twelve months. 
As to shot-firing, he did not know how Mr. Stokes would be 
able to fire all the ripping and coal-face shots required in a 
large mine, with the number of men allowed by the Coal-mines 
Regulation Act, when all the workmen were removed from the 
seam. He thought that only ten were allowed for all purposes, 
including those necessarily employed in attending to engines, 
machinery, horses, etc., and inspecting the mine, and it would 
be impossible for that small number to travel large mines and to 
fire the shots. Shot-firing at the coal-face was an essential ; but 
he should welcome the prohibition of shot-firing in main haulage- 
roads, except under the supervision of officials and when the 



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132 DISCUSSION — THE COURRIERES EXPLOSION. 

workmen were out of the miaes. He very mucli doubted whether 
that could be extended to the gateways, and certainly it could not 
be extended to the working-faces. Shot-firing he was soriy to 
say, had largely increased, and nothing of late years had quite so 
much altered their methods of mining. In one district where 
1,000 tons per day had been got without firing a shot, a consider- 
able number of shots were now fired. Last year, upwards of 
60,000 shots were fired at the Whitwood collieries, and the sug- 
gested prohibition of shot-firing would be a veiy serious matter 
to them; although he ought, perhaps, to add that he did not 
think that six shots had been fired on main roads, and those 
were the only shots which, in his opinion, required special atten- 
tion or protective legislation. 

Mr. A. H. Stokes said that if Mr. Hodges wanted a dusty 
mine, he could tell him where to get one. He (Mr. Stokes) had 
been down a mine, and brought away with him some of their 
dust, which he had not been able to get rid of for days. He was 
surprised that Mr. Hodges thought that ten men were insufficient 
for shot-firing on road- ways, for he concluded his remarks by 
saying that he had not fired six shots on main roads in a year. 

Mr. I. Hodges stated that ripping shots were not included in 
the main-road shots. 

Mr. A. H. Stokes said that he had got the statistics of the 
number of shots fired in his mines-inspection district during the 
last yeai', and he was veiy pleased to congratulate the members 
upon the considerable decrease (88,'Ml) in the number of shots 
fired. He had intended to suggest that, instead of carrying the 
main intake-air in one current and splitting it up into districts as 
near the face as possible, the intake and return-airways for each 
district should be made as distinct as possible, so that if an explo- 
sion occurred it should, if possible, be confined to one district. 
There were many difficulties, but there were other ways of dis- 
connecting districts in old collieries. In his mines-inspection 
district, one mining engineer had thought so much of the 
Courrieres disaster that he had put in iron doors to separate two 
seams. He (Mr. Stokes) had seen them, and he felt satisfied that 
the doors and the way in which they were built in would stop an 
explosion extending from one seam into the other, so far as the 



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DISCUSSION — ^THE COUBBIERES EXPLOSION. 188 

doors were concerned. Supposing it were made obligatory not to 
fire any shots whatever in main road-ways, except under the con- 
ditions suggested, then the rule or regulation containing the 
prohibition might also include permission for more men to be 
allowed in the mine if, as Mr. Hodges contended, ten was an 
insufficient number. The legislative enactment that made pro- 
hibitions could also make extensions, if necessar5^ 

Mr. I. Hodges said that, if they could separate seams with two 
iron doors, it would be much cheaper than the method which he 
was adopting. He asked whether they entirely cut off the intake 
and the return-airways, and closed the passages into the mine. 

Mr. A. H. Stokes said that the doors were used to separate one 
seam from another, and they were put in between the shafts. 
The best plan would be for Mr. Hodges to see them, and he 
would gladly tell him where they were. 

Mr. M. Deacon (Sheepbridge) said that he did not altogether 
see any special advantage in discussing the Courrieree explosion. 
Unfortunately, a number of explosions, equally instructive, had 
happened in this country, and it was only the large number of 
men who lost their lives in the Courrieres explosion that attracted 
80 much attention to it. An explosion in this counti-y in which 
one man was killed might be of as great importance to them, as 
mining engineers, as this disaster in France, in which 1,100 lives 
were lost. All it had done for them was to give rise to a renewal 
of the consideration as to how they, in this country, could reduce 
the risks of similar explosions. He thought, as Mr. Stokes had 
said, that there was ample evidence of a coal-dust explosion in the 
results at Camerton. With regard to the Courrieres explosion, he 
should be extremely sorry to give any opinion, or to come to any 
sort of conclusion, without having seen the mine very soon after 
the explosion. The question of preventing the spread of an 
explosion was a large one. No doubt the arrangement of ventila- 
tion-areas in such a way as to limit any explosion which might 
occur was a proper thing for the members to take into considera- 
tion ; but it was a matter for each colliery manager to consider 
for himself. No general rule could be laid down. The dividing 
of collieries by barriers was absolutely prohibitory, because with 
the deep sinkings which they had in front of them no colliery 



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184 DISCUSSION — ^THE COXTBRIERES EXPLOSION. 

owner would be disposed to sink to much less than 20 square 
miles where only one seam existed. Those were big figures, but 
he was now drawing coal 2J miles from the shaft and doing so 
economically. He was sure that colliery owners were not going 
to sink £500,000 in a colliery without working^ a very large 
area, only limited by the distance over which they could economic- 
ally draw the coal to one shaft. Therefore, the suggestion to 
separate a mine into small compartments for the purpose of 
limiting the effect of an explosion was not within the sphere of 
practical mining. He had made many experiments in watering 
over the past twenty years : he had tried watering by jets, by 
barrels after the manner of street-watering, and also by laying 
water-pipes, with taps at distances of 100 or 150 feet, watering 
the floor, sides and roof of the roads, by means of a hose and rose. 
He was very strongly impressed with the desirability of watering 
wherever the roads would stand it; and where they would, and 
especially where the dust was of a fine and impalpable character, 
they ought certainly to be watered. In the Tredegar explosion, 
they had direct evidence of the fact that watering the roads had 
hindered the progress of the explosion. The explosion occurred 
at the face; the main intake-airway had been perfectly and 
thoroughly watered, but the return-airways had not been watered 
and were very dusty. The explosion took place at the working- 
face, but instead of going out by the intake-airway it followed 
the return-airway to the pit-bottom. Tlie onsetters were burnt, 
and the men in the intake-airways were not touched. He had no 
hesitation in saying that watering did a great deal towards limit- 
ing the seriousness of the Tredegar explosion. 

Mr. J. T. Todd said that Mr. Stokes had recommended him 
very strongly to read the official reports. Would Mr. Stokes 
kindly tell him in what report he would find any record, since 
the Explosives Order was instituted, where an explosion had 
occurred by shot-firing on a main haulage-road with any of the 
present Permitted Explosives? 

Mr. Stokes replied that, if Mr. Todd's remark had reference 
solely to a main haulage-road, he had misunderstood him. He 
believed, however, that there was such a case, and he would 
give Mr. Todd some quotations in confirmation. In the report on 
the Wingate Grange explosion, the verdict of the jury was to the 



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DISCTTSSION — THE COTJERlilRES EXPLOSION. 185 

efEect that the deceased had: been killed " by an eixplosion caused 
by the firing of a shot in the main haulage-way in the Low Main 
seam."* H.M. inspectors of mines report that "the point of 
origin and the initial cause of the explosion was a charge of the 
Permitted Explosive geloxite fired by a stoneman by means of 
fuse on the main haulage-road/' and " the inflammable agent, 
both at the origin and in the propagation of the explosion was 
coal-dust and not fire-damp."t Geloxite wa« a Permitted Explo- 
sive on the present list, and it was only five months since the 
Wingate Grange explosion had occurred. 

The Chairman (Mr. W. G. Phillips) said he felt that the dis- 
cussion was not by any means exhausted, and that the paper 
was a most valuable contribution towards their knowledge of 
extensive explosions. Whatever might have been the cause of 
the explosion, whether it was initiated by coal-dust alone or 
found some assistance from an aqcumulation of fire-damp at the 
seat of the accident, there could be no doubt that it owed much 
of its vitality and devastating power to the dusty condition of the 
roads. He had come to that conclusion by diligently reading this 
paper by Messrs. Atkinson and Henshaw. Confining himself to ' 
the Lecoeuvre heading he found, on making a slight calculation, 
that no less than 19 inches of explosive had been used in the par- 
ticular hole which it was assumed the men were undrilling at 
the time of the accident. Mr. Lewis made a remark to the efPect 
that the three men at the end of the heading were not much 
injured, but there were plentiful indications in the heading, in the 
shape of coked and charred coal-dust, of flame, and the bodies of 
the men were reported by the doctor to be deeply burned. Cer- 
tainly, they had no indication whatever as to the state of the 
ventilation in this particular part of the workings previous to the 
explosion, but there was a pair of levels heading from the top 
of a jig, rising 1 in 6. They had been driven about 600 feet, 
and to his mind it was very ominous indeed that on the date 
when this explosion happened there was no one working in the 
counter-heading. They did not know why, but the workings 

♦ Reports to H.M, Secretary ofStxUefar the Home Department on the Circum- 
stances attending an Explosionwhich occurred at Wingate Grange Colliery, Wingate, 
on the 14th October, 1906, by Mr. A. H, Ruegg, and Messrs. R. D. Bain and 
J. B. Atkinson, 1907 [Cd. 3379], page 13. 

t /6id.,page32. 



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136 DISCUSSION — ^THE COTTRHliRES EXPLOSION. 

were far removed from the downcast shaft, the ventilating' current 
would not be particularly strong, and he was apprehensive that 
at the time the condition of the levels was such as not to be free 
from -gas. He could not exactly make out the course of the 
ventilation; but whether the intake-air went to the top, and 
was then conveyed by pipes to the end of the bottom heading, 
or whether it was the other way about, there could be no doubt 
that the ventilation at that particular point could not be very 
strong. He thought that the condition of the air-pipes, as 
shown by the photographs, was due to an internal explosion. 
It was not one pipe alone which was shattered, but from the 
third air-pipe to the back of the bottom heading, they seemed 
to have been blown to pieces. There was strong evidence 
that something besides coal-dust had initiated this terrible explo- 
sion, althou-gh possibly they might modify their views. The 
great interest taken in this explosion was due to the effect that it 
might have on mining legislation in this country. Lord 
Monksweirs Commission had been dealing with the coal-dust 
question, and they had to bear in mind that when a terrible 
disaster like this took plajce and over 1,000 lives were lost, it struck 
terror into the hearts and minds of the public, and there was a 
tendency on the part of some who knew nothing at all about 
what was required for safety in the working of coal-mines to 
press for unnecessary legislation on the subject. When the 
present Commission sent in their report he was afraid that some 
drastic recommendations would be made to the Government, 
beyond what was required from reasonable considerations of 
safety in this country. It was, therefore, important that discus- 
sions should be held by engineers in order that they might be 
prepared to say what, in their judgment, was needed to avoid 
similar disasters in Great Britain. Watering in all shapes was 
recommended. Some recommended that the watering should be 
in zones, and others over the whole length of the intake roads. 
They might well turn their attention to the prevention of dust, 
as well as to its removal. Mr. W. N. Atkinson stated in his 
report that the condition of the tubs and roads in some parts of 
his mines-inspection district was barbarous. In transporting 
coal from the face to the pit-bottom a great deal might be done 
to prevent the deposit of dust on the main haulage-roads: good 
tubs were essential, which need not be of iron, and slow systems 



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DISCUSSION — THE COtJEElfeftES EXPLOSION. 187 

of haulage wherever they could be adopted. Another point was 
that of the downcast-shaft taking an atmosphere laden with coal- 
dust from the screens, a condition of things that certainly pre- 
vailed at some collieries. The photographs of the surface-works 
at the Courrieres collieries showed an elaborate heapstead, and 
from an architectural point of view everything was very fine; 
but the only parts of the headgear to be seen were the pulleys. 
The downcast-shaft was placed in the midst of the screening 
arrangements and how was it possible that under such conditions 
the air carried down into the workings could be other than laden 
with the finest and most impalpable dust from the screens ? 

The further discussion was adjourned. 



Mr. E. Greaves' paper on the " Elliott Washer and Hardy 
Dust-extractor and Grinder'' was read as follows: — 



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188 ELLIOTT WASHEE AND HARDY DUST-EXTBACTOE. 



ELLIOTT WASHER AND HARDY DUST-EXTRACTOR 
AND GRINDER. 



By E. greaves. 



Inteoduction. 

The growing spirit of economy in the coal-mining industry, 
and the pressure that is being brought to bear on colliery 
managers by the Government authorities to avoid, wherever pos- 
sible, the gobbing of coal on account of the danger of gob-fires, 
without mentioning the national economic side of the question, 
are doubtless to a great extent the reasons why large quantities 
of small coal, which were formerly gobbed, are now drawn to the 
surface. The appliances introduced during the last few years to 
utilize small and inferior coal for generating steam, making 
briquettes, etc., the ever increasing demand for coke, etc., make 
slack and duff, which were formerly looked upon almost as waste, 
a very valuable product. At present there is hardly any class of 
small coal which cannot be utilized either for coking or for 
briquetting, for hand or mechanical firing, if the percentage of 
ash in it is not too high. 

Coal-consumers now seek economy far more than formerly, 
and refuse to buy coal containing much free ash; coal-owners 
are far keener than they were to utilize every possible product, 
and bye-product plants are being erected in all directions, so that 
coal-washers, which at one time were a rarity, are now becoming 
general, and in a few years will become as necessary a part of a 
collierj'^-plant as the screens and sidings. Where there were 
formerly two or three sizes of coal, there are now a dozen, and 
washed peas, washed breeze, washed nuts, smudge, etc., are 
everyday terms in the coal-trade. 

Elliott Washer. 

The Elliott coal-washer is based on the theory of all coal- 
washers, namely, that the coal and shale dirt, being of different 
specific gravities, fall through water at different velocities ; the 
shale being heavier than the coal, if approximately of the same 



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ELMOTT WASHEE AND HARDY DUST-EXTRACTOR. 189 

cubic capacity, offers more resistance to the stream of water and 
settles, whilst the coal bein^ lighter is carried away with the 
stream. The Elliott is an improvement on the old trough- 
washer, at one time so much in favour with colliery managers on 
account of its simplicity and efficacy. Indeed, it only fell into 
disuse because too much depended on the attendant in charge, as 
it wafl necessary to run the coal and water into the second trough 
so soon as the dams or stops in the first trough had got charged 
with dirt ; and, unless this was done at the right moment, the dirt 
in the dams or stops was carried away with the coal, with conse- 
quent bad washing results. The labour required in removing the 
dirt from the dams was a serious item, besides the cost of the second 
trough and the extra space necessary. Furthermore, the old 
trough system was hardly elastic enough for modern requirements. 

The Elliott trough-washer possesses all the advantages of the 
old system without any of the disadvantages, being absolutely 
automatic in its action, requiring no skilled attendant or manual 
labour; and each trough washes continually 
without interruption, the coal and water 
being delivered at the lower, and the dirt at 
the upper end. The Elliott trough (fig. 1), 
which is generally fixed at an inclination of Pio. l.— Though. 

1 in 12, is constructed of cast-iron or steel 

with a flat bottom 18 inches wide, and sloping sides, giving a 
width at the top of 30 inches ; the total length is 60 feet and the 
depth usually 11 inches. At each end of the trough^ sprocket- 
wheels are fixed, which carry an endless chain. At right angles 
to this chain, scrapers are attached at suitable distances, which 
are of the same section as the lower part of the trough. The 
scraper-chain travels along the bottom of the trough to the upper 
end, and runs back over the trough on bracket-rollers, bridged at 
intervals over the trough, the chain being driven by the sprocket- 
wheels at the upper end. The scrapers in this manner form 
travelling dams, which catch the shale and dirt settling in the 
bottom of the trough, and carry them to the upper end ; whilst 
the lighter coal is carried by the water over the dams and 
delivered at the lower end. 

The coal from which the fine dust has been removed is 
delivered into the trough at a point about 25 to 30 feet from the 
top end. The water, being admitted as near the upper end as 



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140 ELMOTT WASHBE AUTD HAHDY DUST-EXTRACTOH. 

possible, runs down the trough and cascades over the scrapers, 
taking with it any coal that may still be mixed with the dirt. 
When it arrives at the delivery-points of the coal, about half-way 
down, its chief determinating action begins ; the heavier shale 
and dirt settle down, and, being caught by the scrapers, are con- 
veyed to the upper end, whilst the lighter coal is washed over the 
scrapers by the stream to the lower end, where it is discharged 
on to oscillating or other water-screens. These practically free 
the coal fronv the water, which runs into a cistern and is 
then pumped back to the upper end of the trough to be used 
again. It will thus be seen that the upper half of the trough- 
length serves to wash the dirt and shale free of coal, whilst the 
lower half serves to wash the coal free of shale. When the 
washer is at work it will be noticed that the scrapers, as they 
begin to ascend the trough at the bottom end, are dammed up 
with coal a« well as shale, the whole, however, turning over and 
over from the action of the water running in the opposite direc- 
tion down the trough. As the scrapers proceed to the upper end, 
it will be noticed that the coal behind the dams is gradually 
churned up and carried away by the water, so that when they 
arrive at the upper end, the scraper-dams are free from coal, and 
discharge nothing but shale and dirt. 

Formerly, the Elliott washer was fitted with flat straight 
scrapers driven by one chain, which gave perfect results with 
nuts, etc., and fairly good results with duff. Practical ex- 
perience, however, shewed that better results might be obtained 
by altering the structure and shape of the scrapers. Duflf requir- 
ing a slower action of the water, it was found that the natural ten- 
dency of the water to follow the line of least resistance caused 
the coal in the middle part of the trough to be perfectly freed from 
shale, whilst the coal at each side of the scrapers was washed less 
eflPectively. To obviate this defect, new types of scrapers, driven 
either by a single or by a double chain have been introduced. 
These scrapers are made either convex or concave, or serrated 
throughout their width, in such a way that the water, on reach- 
ing each scraper, is baffled into several channels instead of run- 
ning in one as formerly. This ensures continuous movement in 
the material as it is transported by the scrapers from one end of 
the trough to the other, and the washing is equally effective 
throughout the whole width of the scrapers. By this arrangement 
the improved Elliott washer can ti-eat perfectly any size of coal 



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ELLIOTT WASIIEa AND HARDY DTTST-EXTH.ACTOK. 141 

down to the finest dust, so that even the finest grains are washed, 
and the dust being so slight a percentage of the whole, it can 
be added to the washed coal without materially increasing the 
percentage of ash ; modem requirements are thus met, the whole 
of the duff utilized, and any loss avoided. 

The troughs are supplied with a differential headstock, so that 
the speed of the scraper-chain can be varied to suit the class of 
coal that is being washed. It is advisable to have a water- 
cistem at the upper end, fitted with spray-taps, so that the 
operator can regulate the volume of water for each size of coal. 

To ensure perfect washing, that is, shale free from loose coal 
and coal free from loose ash, the coal before washing should not 
only have the fine dust carefully eliminated, but it should be 
classified. The Elliott being a stream-washer does not require 
the same amount of classification as in piston and other washing 
systems. Theoretically, the coal being washed should never 
exceed in cubic capacity three-and-a-ha^ f times the size of the 
smallest piece of shale, assuming the averaige specific gravity of 
coal to be 1'4 and that of carboniferous shale 2*4. If the specific 
gravity of the material that is being treated differs from the 
above, the results will be different; but the practical results of 
washing with the Elliott trough, in many countries, and with 
practically every class of coal and shale, have shown conclusively 
that only three sizes are necessary for washing, that is : (a) ^ inch 
to J inch, (6) J inch to | inch, and (c) | inch and upwards. 

Mr. Franz Poech,* in a lecture given in Vienna a few 
years ago, explained the action of the Elliott washer as a 
continued forcing forwards of the particles against the counter- 
acting friction and inertia of the same, the former being of less 
importance than the latter. The particles of coal being treated - 
are exposed to the pressure of the water, and carried forward by 
impact and pressure, so that if p is the pressure of the water ; 
rf, the ideal diameter of the particlest ; and s, the distance along 
which they are exposed to the pressure of the water ; the motive 
force may be written ; F equals pcPs, and the moment of ineiiia, 
M equals P/g, may be expressed thus : — 

2-2-7 ^ ^ 

• " Ueber einige Bergwerksapparate," by Mr. Franz Poech, Oeffterreichischen 
Ztit9chriftfiir Berg- und HuiiernceJien, Vereins-Mittheilungen, 1895, page 35. 

t The ideal diameter is the diameter of a sphere of a mass equal to that of 
the irregular particle. 



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142 ELLIOTT WASHER AND HARDY DITST-BXTRACTOR. 

In the preceding formula, M is the mass ; t;, the velocity in feet 
per second ; P, the weight of a particle in water ; g, the accelera- 
tion due to gravity; and as P equals W(8— 1)/6 where 8 is the 
specific gravity of the coal, then the formula (1) becomes : 

-n- equals hr^ ' Neglecting friction : p(rs equals ^- 

equals -^^ ; t/» equals ^^(^_^y and v equals J ^^j^^Y)' 

Consequently, if - ^ equals the constant C, then : 

" 7.^^, ; ■ ■ .*" 

Similarly for a particle of the diameter, d^, the specific 
gravity, 8,, and at a velocity, Vi, it follows that: 

"^-J^^W^ ■ ...... (3) 

The second (2) equation being divided by the third (8) equa- 
tion, and each side being squared, it follows that : 

v,^^ rf(8-l) ^^^ 

When V equals t'l, the point at which the separation of 
particles of different diameter and different specific gravity 
is no longer possible, the equation (4) becomes : 

It follows, therefore, that sepamtion is no longer possible when 
the diameters of the particles are inversely proportional to their 
specific gravity minus 1. 

This bears out the formula that von Rittinger deduced from 
the laws of gravitation: v equals 2*44v^/a8-1), in which 2*44 
is a constant arrived at from practical experiments.* Thus if 
8 equals 1*4, the specific gravity of coal; and 8, equals 2*4, 
the specific gravity of shale; the equation (5) would show 

that J = «'_ , = f.j _ 1 = fvl = 3*5. Consequently, (f equals 

3*5^1, demonstrating that the diameter of the -grains or 
particles of coal should correspond with the grains or particles 
of shale as 3i to 1. Of course, where a fixed constant is only 
assumed, one naturally doubts a result obtained from such a 
basis, but the writer repeats that many yeai-s' experience of the 
• Tjfhrbuch der Au/bereitungskunde, by Prof, von Rittinger, 1867, page 191. 



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tlthtOTT WASHtJE AND HAEDY DtJST-EXTRACTOK. 148 

Elliott washer in different countries, with all sorts of coal and 
shale, has shewn that to get the best results in washing, the coal 
should be classified in such a way that the smallest grain of 
shale should not be exceeded more than 3^ to 4 times by the 
largest piece of coal in that particular category. One to four 
has been adopted for practical purposes, so that when up to J inch 
is eliminated, for coking or briquetting purposes three sizes only 
are necessary, that is : (a) J inch to J inch, (b) J inch to | inch, 
and (c) I inch and upwards. 

For sale purposes, such as washed smudge, peas, small and 
large breeze, nuts, etc., it is best to classify before washing, and 
treat each size in its trough or troughs according to quantity, 
not losing sight of ihe economical question as regards the number 
of troughs. 

The output per trough depends on the size and nature of the 
coal that is being treated, but generally varies from 4 tons per 
hour for the smallest size (i inch to J inch) up to 12 tons per hour 
for large nuts. If the number of troughs be limited, and classifi- 
cation after washing be compulsory, the screening should be 
confined as far as possible to the larger sizes. 

Hardy Dust-extractor. 

The removal of very fine dust is always a matter of some 
difiiculty, especially if the coal be damp or sticky, unless 
hydraulic screens are used ; and sometimes it has been found to be 
impossible to screen out anything less than J inch. Where only 
small breeze was washed, say, up to J inch or | inch, it was found 
impracticable to eliminate J inch as it formed too great a propor- 
tion of the coal that was being treated ; and when attempts were 
made to remove | inch the holes in the screen-plates became 
clogged, and the screening results were very bad. Experiments 
were made in order to overcome this difficulty, which resulted 
in the introduction of the Hardy dust-extractor, a very simple 
contrivance. With this dust-extractor, it is possible to extract 
down to xV ii^ch if the coal is dty, so that all the coal from xV 
inch upwards can be washed. Any sized grain of coal can be 
treated successfully with the Elliott washer ; the only un washable 
stuff is the very fine dust, and, in consequence of the possibility 
of washing down to yV inch, all the dust may be added to the 
washed coal without increasing seriously the percentage of ash 
in the whole. 



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144 ELLIOTT WASHER AXD HARDY DUST-EXTRACTOR. 

As the whole of the dust and schlamm are used, there is 
practically no loss with the improved Elliott washer, the output 
of coke per 100 tons of coal treated being higher than with any 
other system. 

The Hardy dust-extractor is fitted over the screen which sizes 
the coal that enters the washing troughs. The small stuff, up to § 
inch falls into a hopper or receptacle, fitted with two or three 
angular plates or bafflee, so arranged as to spread the falling 
material into a thin stream. In its descent it comes into contact 
with a current of air from a fan, or induced draught, sufficiently 
strong to carry away the fine dust-particles and draw them 
through an opening into a special chamber; whilst the larger 
stuff falls down a shoot on to a conveyor, which delivers it into 
the washing troughs. The dust-outlet is fitted with a baffling 
screen to prevent any stray grainy from escaping with the dust, 
which is carried into a special hopper where it is delivered on to a 
conveyor and transported to the disintegrator to be wall mixed 
with the washed coal whilst being ground. The dust-hopper or 
chamber is fitted with an opening at the top, to allow of the air 
escaping when the coal-dust has settled. If the dust, which is 
removed, contains a high percentage of ash, the whole of it 
cannot, of course, be added, as this would increase too greatly the 
percentage of ash in the washed coal. For example, if the coal- 
dust under iV inch be estimated to represent 10 per cent, of the 
whole of the coal to be treated, assuming that the dust from 
to ^V i^oh contain the same proportion of ash as the larger 
coal, and assuming that the ash in the coal be reduced from 15 
per cent, to 5 per cent, by washing, the addition of the whole of 
the dust would increase the percentage of ash in the washed coal 
to 6J per cent., or if only half the eliminated dust were added, to 
about 5i per cent. 

This mixture of the whole, or certain proportions, of the dust 
with the washed coal renders the Elliott washer as elastic as the 
more complicated and costly systems, because the percentage of 
ash in the coal, coke or briquette can be regulated according to 
the exigencies of the contract or the market. In the preceding 
example the minimum is 5^ per cent, and the maximum 6^ per 
cent, of ash, schlamm being left out of the question, as it amounts 
generally to only 2 tons per 100 tons treated, if the dust is 
well screened out; but, if a higher maximum limit is required, 



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ELLIOTT WASHER AND HARDY DUST-EXTRACTOR. 146 

this can be easily obtained by eliminating up to J or f inch by 
regulating the dust-extractor accordingly. In the c-ase of coal 
not destined for briquetting or coking, the desired proportion of 
dust should be mixed only with the smallest size of washed coal, 
as added dust spoils the appearance of beans and nuts ; in fact, 
where washed coal is not coked or briquetted, it is better to have 
an extra category of small to receive the dust and to be disposed 
of as washed smudge. 

Working of the Elliott Washer. 

If the dust be well eliminated, a settling pond or tank is not 
absolutely necessary in washers for coking or briquetting pur- 
purposes, as the proportion of schlamm is very small (about 2 per 
cent.) so that the density of the water is not seriously afiEected, 
and the washing results remain practically the same with or with- 
out decanting tanks. But, in the case of washed coal for sale, 
tanks are advisable, as a finer washed sample is produced if the 
schlamm is allowed to settle in a decanting tank. Even if the 
nuts are sprayed with the fresh water, the final result with this 
class of washer (non-coking) is not so satisfactory as with some 
systems of decantin-g the water before it is used again. The 
different mode of action in the piston-type of washer entails far 
more classification to get the best washing results, which explains 
many of the complications in this class of washer, leading to 
increased friction and consequent increase of the schlamm, the 
bugbear of coal-washing. 

It is satisfactory to know that the schlamm in the Elliott 
washer is reduced to an absolute minimum, as the coal only 
undergoes one operation, whilst in the more complicated piston- 
washers it is transported to and fro, which results in increased 
friction, causing a larger proportion of schlamm. In some 
Elliott washers settling tanks are dispensed with, the water from 
the troughs being collected in a receptacle tapered down to the 
inlet-pipe of the pump, the schlamm circulating with the water 
until it settles either with the coal or with the dirt. This process 
of settlement is so regular that the fresh delivery-water suffices to 
keep the water sufficiently clear to get good washing results. 
There are Elliott washers with settling tanks giving only 4 tons 
of schlamm per week on a total output of 1,600 tons, or J per 
cent. ; in other washers the quantity of schlamm will reach 2 per 



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lis ELLIOTT WASHER AND HARDY DUST-EXTRACTOR. 

cent., much depending' on the nature of the coal, the effective 
removal of the dust, and good practical water-screens. 

Where the difference between the specific gravity of the coal 
and that of the dirt is small, the question of the inclination of 
the trou-gh is important ; but an inclination of 1 in 12 is suitable 
for general purposes, and is usually adopted. Generally, coal 
upwards of 2 inches in diameter is not washed, hand-picking 
being more practicable ; but if coaJ between 2 and 3 inches is to 
be washed, an inclination of 1 in 10 will be found to yield better 
results. 

For the larger sizes of coal, such as nuts, etc., scrapers 4 to 5 
feet apart and 2| inches in depth will give perfect results; but 
for the smaller sizes, such as beans, smudge, etc., the scrapers 
should be fixed only 2 feet to 3 feet apart and 1^ inches to 2 inches 
in depth. By adapting the speed of the chain, the number and 
height of the scrapers, the inclination of the trough, and the 
volume of water to the class of coal that is being washed, abso- 
lutely perfect washing results may be obtained with any coals 
which differ in specific gravity from the shale that is to be washed 
out: this is done at one operation, proving this to be the 
simplest, most effective, and most adaptable coal-washing system. 
This adaptability and elasticity are of vital importance, as, for 
instance, where the coal being treated contains any batten coal, 
or coal with streaks of shale, the water can be so regulated as 
to deliver it either with the shale or with the coal, as required. 

The Elliott washer possesses an advantage over the piston- 
washer that is not generally known, namely', its effective treat- 
ment of shale-flats, and the thin lenticular shale so prevalent in 
some coal-seams. These float away with the coal in the piston- 
washer, whilst the peculiar dam-action of the trough-washer 
ensures the flat thin shale being caught long before it reaches 
the lower end of the trough ; and, when once shale gets caught in 
a scraper, it i-arely escapes before it is expelled at the upper end. 
The writer does not maintain that it is impossible for a thin 
piece of shale to escape with the coal, but he contends that the 
proportion is veiy trifling compared with the piston-type of 
washer. The writer has seen washed nuts from a large modem 
piston-washer plant being treated by special screens, so con- 
structed that the cubical nuts ran over the screens, whilst the 
flat lenticular pieces of shale fell through the narrow specially 
arranged meshes. There were such large quantities of this 



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feLiJOTT WASHER AND HARDY DUST-EXTRACTOR. l47 

lenticular shale, that the nuts were practically unsaleable until 
it was removed. 

It is evident that the motive power required for washing with 
the Elliott trough is considerably less than for washing in a 
piston-washer, and that the maintenance-charges are a mere 
trifle in comparison. The wear-and-tear is practically confined 
to the scrapers, which, being of very simple construction, can 
be easily made by any oi-dinary colliery-smith in his spare time. 
If the water which is used is moderately free from acid, the 
trough-sheets will last for years. 

After it is once regulated for the coal that is being treated, 
the Elliott washer requires no attention, so that the man in 
charge can devote the bulk of his time to some other work. 
When the washer is stopped, all the water at once runs down to 
the pump-well so that no airtight buildings are required, as 
nothing can freeze even in the severest winter ; and, as there is 
no quick running or heavy machinery, only a light structure is 
required. In plants for coking or briquetting, the grinding 
machinery is always placed on the ground floor. Each ton of 
coal that is being washed requires about 700 gallons of water in 
circulation ; and, if the dust is well eliminated and the proportion 
of breeze and nuts is about equal, the water-wastage will be very 
low, well under 5 per cent., 35 gallons per ton washed : for the 
Elliott water-screens are very effective, and the wastage is con- 
fined to the water in the washed coal. It will be found that 
very little fresh water is necessary to keep up the washing 
supply if special arrangements are made to free the washed coal 
thoroughly from water by running it on a perforated conveyor 
as it is delivered from the water-screens, the conveyor being 
provided with catch-drops at suitable distances to shake and 
turn over the coal. 

It is impossible to determine the motive power that will be 
required, as so much depends on the material being washed, the 
height of the elevators, and different local conditions; but there 
is not the slightest doubt that, whatever the conditions may be, 
far less power is required for the Elliott than for the piston 
type of washer. There are several Elliott washers now working 
which treat 1,000 tons per day of 10 hours and are driven 
entirely by a 90 horsepower engine, the plant including duff- 
screens, sieves, elevators, pumps, scraper-chains, water-screens, 
disintegrators, etc. 



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148 ELLIOTT WASHER AND HARDY DUST-EXTRACTOR. 

The working expenses, power, labour in washing, cleaning 
out settling tank, repairs, belting, oil, etc., vary from Id. to lid. 
per ton, excluding the sinking fund for redemption of capital, 
which may vary from £5,000 for a washer capable of treating 
1,000 tons per day of 10 hours, up to £10,000, according to the 
class of building and general elasticity required in the washer. 

If the dust is well screened out and the coal classifie<l in three 
sizes, the first up to I inch, the second J inch to | inch, and the 
third over 3 inch, it will be found that there is practically no free 
coal in the shale, and that the washed coal, on analysis, shows only 
i to 1 per cent, more than its natural fixed ash, the lower 
percentage being obtained with coal containing, when unwashed, 
12 per cent., and the higher with coal containing, when un- 
washed, 17 to 20 per cent, of ash. 

The main advantages and features of the Elliott washer, as 
compared with the piston-type, are as follows : — Low initial cost, 
greatly reduced labour-charges, very low repair and maintenance- 
charges, great reduction in motive power, utilization of the 
whole of the duff or dust, minimum of wastage, and maximum 
of elasticity and eflBciency. 

Devil Disintegrator. 

A very important factor in coking and briquetting is the grind- 
ing apparatus. It is not generally and suflficiently recognized 
how important a part the grinder plays in the structure of the 
coke. However small the coal may be ground, the uniformity 
of the grain is of vital importance. With the ordinary double 
disc bar disintegrator, it is impossible to secure a regular uniform 
sample, and it will be found that there is always a great variety 
of dust, of small and larger grain in the product of this type of 
disintegrator, which results in the coke being too badly fissured 
and broken up. 

The devil disintegrator consists of two rings fitted with rows 
of teeth of different sizes arranged in concentric circles, one of the 
rings being fixed and the other revolving, the teeth of the revolv- 
ing ring fitting into the interstices of the teeth of the fixed ring. 
By means of a simple attachment on the revolving ring, it can be 
brought closely into contact with, or at any desired distance from, 
the stationary ring, thus enabling the operator to grind to any 
desired size and ensuring greater uniformity in size of coal 
ground than with the bar type of grinder, which is more percus- 



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DISCUSSION ELLIOTT WASIIBB, AND HAKDY DUST-EXTEACTOR. 149 

sive in its action and produces a mixture of very fine coal-dust 
and different sized grains. Coal ground by the devil disinte- 
grator yields coke of a better structure than coal pulverized by 
the bar-type of disintegrator. There is an arrangement in the 
devil disintegrator which prevents coherence, an important fea- 
ture with wet coal, or a mixture of coal and pitch for briquetting. 
The rings are made of cast-iron well chilled ; and they last 
about 12 months, if the rings are reversed in running when the 
teeth on one side are ground down. No reserve disintegrator is 
necessary, but simply a pair of reserve rings, which can be fixed 
by an ordinary labourer in an hour. The devil disintegrator only 
requiies one belt, it is eeusily dismounted, and takes less power 
than an ordinary disintegrator. 

Many may wonder why so many foreign complicated and 
costly washers, costly both as regards initial outlay and cost of 
running and maintenance, have been and are being erected in 
Great Britain, when so cheap and effective a washer has been 
designed and constructed in this country. Germany was the 
pioneer of modem coal-washing, and brought to the front the 
economic questions of utilizing waste by manufacturing 
briquettes and recovering bye-products, using the waste-gas for 
power purposes, and classifying coal so as to render it suitable for 
each class of consumer ; in fact there is no doubt that German 
engineers were at work in this direction, and recognized the 
importance of utilizing waste, etc., many years before their 
British colleagues. This fact has given German constructors a 
certain advantage, and many British colliery managers have the 
impression that anything up-to-date in this particular line can 
only be procured abroad. This may have been the case 10 years 
ago, but certainly not to-day. 

The Chairman (Mr. W. G. Phillips) said that the arrange- 
ment described by Mr. Greaves appeared to have many merits. 
It utilized not only coal, but other stuff, to which, in the ordin- 
ary state of the market, customers objected. He had much 
pleasure in moving a heariy vote of thanks to Mr. Greaves for 
his paper. 

The resolution was unanimously agreed to, and the discussion 
was postponed to a future meeting. 



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150 DISCUSSION — ELECTRIC WINDING FOR liAIN SHAFTS. 

DISCUSSION OF MR. W. C. MOUNTAIN'S PAPER ON 
THE " COMMERCIAL POSSIBILITIES OF ELECTRIC 
AVINDING FOR MAIN SHAFTS AND AUXILIARY 
WORK."* 

Mr. Maurice Deacon said that he was not going to criticize 
Mr. Mountain's paper, because he agreed with it. He thought 
that the gratitude of the members was due to Mr. Mountain for 
coming forward in such a pure engineering spirit and telling 
them not to use electrical winding where steam-power could be 
applied direct, although such advice was opposite to his interests. 



Mr. G. J. BiNNS moved a vote of thanks to Mr. W. G. Phillips 
for his services in the chair. 



TrafU, Inst, M. E„ 1906, vol. xxxi., page 329. 



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ANNTJAL REPORT OF THE COUNCIL. 161 



THE MINING INSTITUTE OF SCOTLAND. 



ANNUAL GENERAL MEETING, 
Held in thb Hall of thr Institutk, Hamilton, April 11th, 1907. 



Dr. ROBERT THOMAS MOORE, President, in the Chair. 



The minutes of the last General Meeting- were read and 
confirmed. 

The annual report of the Council was road as follows : — 

ANNUAL REPORT OF THE COUNCIL, 1906-1907. 

The Council have pleasure in submittin-g their twenty-ninth 

annual report. 

The number on the roll, at present, is aa follows : — 

Honorary Members 4 

Life Members 9 ^ 

Life Associate Member 1 

Members (subscription £2 28.) 175 

Members (subscription £1 5s.) 276 

Associate Members 31 

Associates ]«S 

Students 18 

Non-federated Life Member I 

Non-federated Members (subscription £ 1 Is.) 12 
Non-federated Members (subscription 10s. 6d. ) 4 

Total ... 644 

This number compares with that of last year as follows: — 

On the roll at April, 1906 524 

Added during the year 48 

Total ... 572 

Died 4 

Retired 10 

Gut off through non-payment of 

subscriptions 14 28 

At present on the roll 544 

This statement shows a net increase of 20 during the year. 
The following i>aper8, with discussions thereon, have been 
before the members and published in the Transactions : — 



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1«'>2 ANNUAL REPORT OF THE COUNCIL. 

"Electric Power-station, Winding-gear and Pumping-plant of the Tarbrax 

Oil Company, Limited/' By Mr. James Caldwell. 
"Acetylene Safety. lamps." By Mr. L. H. Hodgson. 
" The Wolf Safetylamp. " By Mr. L. H. Hodgson. 
"Non-rotating Wire-ropes, and Tests of Wire-rope Attachments." By Mr. 

Ernest King. 
" Notes on the Detection and Estimation of Inflammable Gases in Mines by 

Means of Flame-caps." By Mr. Charles Latham. 
" The McCutcheon Gas-detector." By Mr. Robert McLaren. 
" Heading by Long wall Machines." By Mr. Sam Mavor. 
" Effects of Acceleration on Winding- torques, and Test of Tarbrax Electrical 

Winding-plant." By Mr. George Ness. 
" The Gold-field of Paracatti, Minas Geraes, Brazil." By Mr. Hugh Pearson. 
"A Diamond Hand-boring Machine." By Mr. John B. Thomson. 
" Tests of a Mine-fan." By Mr. John B. Thomson. 

Through the kindness of the Tarbrax Oil Company, Limited, 
the members had an opportunity of inspecting the electric 
installation at Tarbrax oil-works in June last, a special feature 
being the electric winding, which is the first of its kind in 
Scotland. There waa a large turn-out, and the excursion was 
very successful. 

On the occasion of the visit of the American Institute of 
Mining Engineers to this country in August last, an oppor- 
tunity was afforded, in conjunction with the West of Scotland 
Iron and Steel Institute, of entertaining them to an excursion 
by chartered steamer on the Clyde, a mark of courtesy which 
was greatly appreciated by the visitors. On the evening of the 
same day, the Lord Provost and Magistrates of Glasgow gave 
a reception in the municipal buildings to the joint Institutes. 

The issue of a new catalogue of the Library, at the beginning 
of the year, has served to quicken interest in the large collection 
of books which the Institute now possesses, and which is being 
constantly added to by purchase and exchange. 

The donations to the Library during the year, in addition 
to those received by exchange, are aa follows ; — 

Donors. Donations. 

Mr. Robert McLaren. Mines' Reports and Statistics 1904-1905, 2 volumes. 

Mr. J. T. Robeon. Mines' Inspector's Report, 1905, Swansea District. 

Mr. J. M. Ronaldson. Mines' Inspectors' Reports, 1905, 13 parts or 

volumes. 
Mr. G. Henriksen. Pamphlet on Sundry Geological Problems. 

Messrs. John Watson, Case with the complete core of a diamond bore from 
Limited. the Splint seam to the Drumgray coal-seam, near 

Hamilton. 



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TRANSACTIONS. 168 

The financial condition of the Institute is satisfactory, as 
shown by the Treasurer's accounts. 

There have been nine meetings of Council during the year. 



The report was unanimously adopted. 



The annexed abstract of the Treasurer's accounts was read 
and adopted. 



The following gentlemen were elected : — 

Membebs — 
Mr. CharlEkS Atherton Atchlby, c/o Messrs. G. Harland, Bowden & Co., 

Baltic Chambers, Glasgow. 
Mr. James Cooper, 1 Roseneath Terrace, Edinburgh. 

Mr. Andrew Sneddon Howie, Messrs. Backus & Johnston Co , Casapalca, Peru. 
Mr. Thomas M'Meekin, Forth View Cottage, Wallyford, Musselburgh. 
Mr. John W. M*Trustt, Technical College, Wigan. 
Mr. John Sneddon, Comsilloch Colliery, Netherbum. 



ELECTION OF OFFICERS, 1907-1908. 

Office-bearers for the session 1907-1908 were elected as 
follows : — 

President : 
Dr. Robert Thomas Moore, 142, St. Vincent Street, Glasgow. 

Vice-Presidents : 
Mr. Archibald Bltth, Lochside, Hamilton. 
Mr. James Hamilton, 208, St. Vincent Street, Glasgow. 
Mr. Thomas H. Mottram, 6, Kelvinside Gardens, N., Glasgow. 
Mr. Thomas Thomson, Fairvlew, Hamilton. 

Councillors : 
Mr. James Armour, St. Abbs, Leven. 

Mr. Thomas Arnott, 12, Garrioch Drive, Kelvinside, Glasgow. 
Mr. James Bain, The Whins, Alloa. 

Mr. Harrt D. D. Barman, 21, University Gardens, Glasgow. 
Mr. Adam Brown, AUanton Colliery, Hamilton. 
Mr. John T. Howat, Stobbs Mouse, Kilwinning. 
Mr. William Howat, North Motherwell Colliery, Motherwell. 
Mr. Douglas Jackson, Coltness Iron-works, Newmains. 
Mr. Thomas J. Jamieson, Motherwell Colliery, Motherwell. 
Mr. James M*Phail, Bog Colliery, Bothwell. 
Mr. John Mbnzies, Auchinraith Colliery, Blantyre. 
Mr. J. Balfour Sneddon, Oakbank Colliery, Mid Calder. 



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154 



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DISCUSSION — ^TESTS OF A MINE-FAN. 155 

DISCFSSION OP MR. JOHN B. THOMSON'S PAPER ON 
"TESTS OP A MINE-PAN."* 

Mr. James Black (Airdrie) said that Mr. Thomson had made a 
few mistakes in finding the effici-ency of the fan. In the first 
test, the indicator-diagrams, to determine the average steam- 
pressure in the cylinder, were taken when the engine was run- 
ning at 90 revolutions per minute ; and the necessary measure- 
naents to determine the horsepower in the air were taken when 
the engine was running at 92 revolutions per minute. Of course 
it was necessary, before Mr. Thomson could calculate the effi- 
ciency of the fan, that he should find the horsepower in the air 
and the horsepower in the steam-cylinder when the engine was 
running at the same number of revolutions in both cases. These 
calculations could have been accomplished in two different ways, 
either by finding the horsepower in the steam-cylinder when the 
engine was running at 92 revolutions per minute, or by finding 
the horsepower in the air when the engine was running at 90 
revolutions per minute. Mr. Thomson selected the latter method, 
and in making this adjustment h.e incorrertly a,s8umed that the 
horsepower in the air varied directly as the revolutions of the 
engine. Actually the horsepower in the air varied directly as 
the cube of the revolutions of the engine, and consequently the 
accuracy of Mr. Thomson's result was seriously affected. Thus, 
instead of the efficiency being 878 per cent., it was 83*98 per 
cent. He could not say whether there was a similar mistake in 
the other tests, as the information was not available in the 
paper. However, the valuable deduction could be ma<Ie that, in 
finding the efficiency of a fan, the various operations should 
always be carried out simultaneously. 

He (Mr. Black) thought that another mistake had occurred 
in the third test : the air-current in that test wa,s measured under- 
ground, and the water-gauge was 208 inches in the fan-drift, and 
116 inches underground ; Mr. Thomson stated that '* the water- 
gauge due to the differences of temperature, calculated on the 
depth of the Main coal-se^im, was Oil inch ; and the actual water- 
gauge due to the fan was (203 — O'll or) 1*92 inches." Mr. 
Thomson had erroneously assumed that the reading of the 
water-gauge on the fan-drift included the water-gauge due to 
the differences of temperature in the shafts. The ** natural " 
* Trans. Inst. M. E., 1906, vol. xxxii., page 295 ; and vol. xxxiii., page 58. 
TO J*, xxx1u.-1w.wg7. 12 



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156 DISCXTSSION — ^TESTS OF A MINE-FAN. 

water-gauge did not increase the efficiency of the fen, 
although it assisted the ventilation of the mine, but that was 
an entirely different matter. Mr. Thomson was actually not 
crediting the fan with work which it had leflritimately accom- 
plished, and consequently he arrived at an inaccurate result; 
and, instead of the efficiency being 64*2 per cent., it was actually 
67*8 per cent. He (Mr. Black) could not understand why Mr. 
Thomson in his summary did not notice that something was 
wrong with one or other of his results, because in the first and 
second tests the water-gauge due to the differences of shaft-tem- 
perature were eliminated ; and it was taken into consideration in 
the third test. Had he been justified in this exclusion in one 
test, surely he would have been justified in all, unless the average 
temperature in both shafts was the same, and this, of course, was 
not probable. This error affected the efficiency in the fourth 
test; and, instead of the result being 865 per cent., it was 
actually 91'3 per cent. 

Mr. John B. Thomson, in thanking the members for the way 
in which they had received his paper and more especially the 
gentlemen who had taken part in the discussion, said that he had 
been specially interested in the communication by Prof. A. 
Eateau, who mention^ that the measurements ought to have 
been made with a Pitot tube. He had read Prof. Rateau's paper 
on " Experimental Investigations upon the Theory of the Pitot 
Tube and the Woltmann Mill,''* and found that the water-gauge 
tube should have been held like the Pitot tube, namely, against 
the air. If that had been done, the efficiency of the fan would 
have been reduced, as Prof. Rateau had remarked, from about 
86 to 55 per cent. ; but that did not explain the great differ- 
ence between tlie measurements of the air in the mine and 
on the surface. The fan-drift was not quite level : it dipped 
about 1 in 6 ; and Mr. T. H. Mottram vividly described the whirl 
that took place in that drift. Mr. James Black took exception 
to the way in which the air had been measured, and thought that 
the nine spaces, into which the fan-drift was divided, were too 
large ; but 4 square feet might be considered as a small enough 
area. Mr. Black also took exception to the system of shelves 
as against dividing the fan-drift into squares with wires and using 

• Tratvi. Inst. M, E., 1899, vol xvii., page 124. 



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DISCUSSION — HEADING BY LONGWALL MACHINES. 167 

the anemometer on the end of a rod. The rod could be used 
in two ways: (1) The anemometer could be mounted on the end 
of the rod, so that the observer must stand behind it and move 
himself about with it keeping* the rod level ; but it was difficult 
to keep the anemometer parallel to the section of the fan-drift, 
and an eddy was set up by the body of the operator bein^^ placed 
so near the instrument. (2) The anemometer could be mounted 
on the side of the rod, and the operator would then stand in 
the section where the air was being measured. This method 
was subject to several difficulties, especially if the fan-drift was 
large with va lying velocities of the air in the different spaces. 
Great difficulty was experienced in keeping the aaemometer in 
the section, when changing from space to space. Further, the 
operator standing in the section reduced its area and set up eddies. 
He thought that the system of shelves, taken off to a knife-edge 
facing the current, was the better method, as the fan-drift was 
entirely clear of men during the 5 minutes' duration of the read- 
ing in each space. It took a very short time to start the anemo- 
meter and for the operator to retire from the section. It was 
evident that the efficiency of a fan was not easily determined 
when measuring the air so near the ear of the fan, and more 
especially in the case of small quick-running fans. 

The Peesidbnt (Dr. R. T. Moore) said that the question of 
measuring the quantity of air going into the fan-drift was a 
difficulty which many members had experienced. The difficulties, 
brought out in the course of the present discussion, illustrated 
the advantage of bringing subjects of this kind before the notice 
of the members. 

The discussion was closed, and a hearty vote of thanks was 
awarded to Mr. Thomson for his paper. 



DISCUSSION OF MR. SAM MAYOR'S PAPER ON 
"HEADING BY LONGWALL MACHINES."* 

Mr. R. W. Dbon (Glasgow) said that he could not speak from 
his own experience of the bar-type of machine, but in regard to 
that type of coal-cutting machine further evidence would be 
required before accepting all the claims put forward on its behalf. 

* Trans. Itut. M. E,, 1907, vol. xxxiiL, page 65. 



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158 DISCUSSION SHEADING BY LONGWALL MACHINES. 

The idea of opening out work with a coal-cutting machine was 
being genel-ally adopted. Mr. Mavor's paper was founded on 
the assumption that the bar cutter could do something which 
could not be done with any other coal-cutter; and he remarked 
that ** the feature of the longwall bar machine, especially adapt- 
ing it for heading work, is the anangement which enables it to 
cut-in at one end of the face and cut-out at the other — thus 
avoiding the necessity for stable-holes.*'* Perhaps some mem- 
bers, who had bar coal-cutters and were doing without stable- 
holes, would give their experience. Enquiries addressed to 
engineers, who were using bar cutters, bixnight forth the reply, 
*' stable-holes are made, the same as for any other machine."' 
Table I.t showed that in a place 90 feet wide an area of 60 square 
yards was undercut per shift of 8 hours ; and that the total cost 
was £1 13s. 9d. jjer shift, which comprized £1 4s. for thrc<» men 
at 8s. per shift, and 9». 9d. for power-supply, etc. He could not just 
follow whether Mr. Mavor meant that these thi-ee men were em- 
ployed for 8 hours in this 90 feet place, because Mr. Mavor also 
said that it could be done in 4 hours.J (1) If the work were done 
in 8 hours, Mr. Mavor's machine would cut across the face in 1 
hour at the rate of li feet per minute ; and, consequently, 7 hours 
and a proportionate part of the £1 13s. 9d. were employed in turn- 
ing the machine and cutting the comers. (2) If the work were 
done in 4 hours, allowing a cutting speed of 1^ feet, 1 hour would 
be occupied in cutting and 3 hours and three-fourths of £1 13s. 9d. 
would be spent in turning the machine and forming the comei-s. 
And, in addition, the man who was working the comers and 
breaking down the coal to this nice curve would require pay- 
ment at the rate, at least, of Id. a ton extra on that place, unless 
the coal was exceptionally favourable. Consequently, the cost 
for the corners was practically the same with the boi' type of 
machine as with the disc type. These figui'es, however, did not 
altogether vitiate Mr. Mavor's main contention, that the longwall 
coal-cutting machine could be utilized for driving headings. He 
(Mr. l)ron) was driving faces with widths of 200 feet or so, with 
an ordinary disc machine. Where the holing was reasonably soft, 
a channelling machine would not give any benefit in driving 
narrow headings, but it would show great economy' when com- 

* Trans, InsU M, E., 1907, vol. xxxiii., page 67. 
t Ibid., page 68. J Ibid,, page 72. 



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MscTJssioN — ^Heading bH Longwall iiACHiKEs. 159 

pared with haad-labour in a hard holing. Mr. Mavor's was a 
valuable paper, and he hoped that criticism and further informa- 
tion would be supplied by members who were using< the bar 
machine. 

Mr. John Blake (Hamilton) said that the bar coal-cutter at 
Eddlewood colliery cut in and cut out. The machine was 
turned on th© last road-head, and usually took 35 minutes. The 
best speed, for 8^ hours actual cutting-, was 450 feet of longwall 
face cut to a depth of 3 feet. 

Mr. Thomas Stevenson said that at Eamock colliery the bar 
machine cut out its own stables both at the bottom and at the 
top. The machine was turned on the last road-head, and took 
about 45 minutes, but it depended on the pavement. Places at 
the rib-side were not paid anything extra : this work being piiid 
at the same rate as the rest. The bar machine seemed to suit 
their requirements better than the disc machine because the 
coal was inclined to go down. With the disc machine, two men 
were required to shovel back. There was no difficulty in the 
bar machine cutting into any level, cutting straight and with- 
out any stables. 

Mr. Thomas Arnot (Glasgow) said that he had used the bar 
mlachine in opening two machine-sections by two branching 
headings with about 150 feet of face. The machine, with a 6 
feet bar, could easily cut 150 feet to a depth of 6 feet in 8 
hours. Some difficulty was experienced as the coal gave way; 
and, at the same time, they had difficulty in stripping. It took a 
little time to turn the machine, probably about an hour. It 
took a little time, too, to get the bar into position, depending 
on the length of the bar and the material into which it was cut- 
ting. The bar machine was a good one for opening up two 
sections simultaneously and quickly at a small cost. 

Mr. Thomas Thomson (Hamilton) said that he had made a 
turn-table, as he thought that it would be of great advantage 
and save time in tui-ning the machine: but he found that it 
occupied much space, the machine being 14 feet in length ; and 
the roof would not stand over so great a width. However, a 
machine could be turned in 30 minutes; he thought that this 
was speedy work, and was content to work without a table. 



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160 DISCUSSION ^HEADING BY LONGWALL MACHINES. 

Mr. John McLuckie (Larkhall) said that he was much siir* 
prised at the remarks of Messrs. Thomson, Blake and others who 
said that the bar machine holed its own stables. Mr. Mavor's dia- 
grams showed that part of the stable must be cut out at the end ; 
and, wherever Mr. Thomson turned the bar machine, some part 
must be left. And further, if Mr. Thomson turned the machine 
at the nearest road to the end, it must cut up to the comer with 
the bar in front to finish the run ; by so doing, he adopted the 
method to which he strongly objected of cutting with the bar 
in front. The bar machine was giving good results in longwall 
heading, in the manner suggested by Mr. Mavor. If it was the 
case that no payment was made for the comers, then the bar 
machine was in a very favourable position compared with the 
disc machine. Mr. Mavor stated that the wages of the workmen 
were £1 4s. for three men ; but, in the Larkhall district, where 
the seams were very thin ajid the work not too comfortable, the 
machineman, and the second and third hands expected substantial 
wages. He thought that Mr. Mavor would i^eciuire to enhance the 
wages of his workmen. 

Mr. Sam Mavor said that the claim of the longwall bar 
maehine to inclusion in the list of heading machines was amply 
justified by its performances, examples of which were given in 
the paper. It was true that the disc-type of machine could also 
be used for advancing places about 90 feet wide ; but it must be 
quite obvious to members who had experience in handling both 
disc and bar machine®, that the latter hiid special advantages 
when applied to work of that kind. The point that he wished 
to bring out in his paper was that the application of the bar 
machine in the method described (holing 6 feet deep and cutting- 
in and cutting-out at the ends of the face) allied rapidity of 
advance with the economies of longwall working. The diffi- 
culty instanced by Mr. Arnot could be easily overcome by in- 
creasing the diameter across the cutters near the i-oot of the bar. 
The ellect of this slight modification was to increase the height 
of the cut at the front, giving the coal a greater distance to drop 
and allowing it to fall forward. This method of tapering the 
cut was used in undercutting thick seams in a number of col- 
lieries in England. Formerly, when the machines were mounted 
on rails, turn-tables had been used for turning the machines; 



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DISCtTSSION — ^HEADING BY LONGWALL MACHINES. 161 

but, since the introduction of skids, it was found that the 
machine could be more easily turned without a turn-table. Mr. 
Thomson had said that the machine on skids was turned in 
about 30 minutes, and this time could not be :^eatly decreased. 
The wages quoted in Table I. were those actually paid for the 
minimum shift of 8 hours. The time required to cross the 
short face was less than a shift ; and, therefore, the whole work 
might be profitably contracted, and the machineman could assist 
in filling coals or at stone- work 

The discussion was then closed, and a hearty vote of thanks 
was awarded to Mr. Mavor for his paper. 



Mr. Henry Simonis gave a demonstration of the use of the 
Aerolith liquid-air rescue-apparatus.* 



Mr. John F. K. Brown iTad the following paper on 
'* A Stretcher for Use in Mines " : — 



* ''Liqaid Air and its Use in Rescae-apparatus," by Mr. Otto Simonifl, 
Trans, Inst, M, E,, 1906, vpl. xxxii., page 534, 



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162 A STHETCHER FOR USE IN MINES. 



A STRETCHER FOR FSE IN MINES. 



By JOHN F. K. BROWN. 



There can be no doubt that, in many cases, the present 
methods of removing injured men from the working-faces are 
very inadequate. 

The proposed stretcher is designed to carry men to the shaft- 
bottom in comparative ease and comfort. It consists of several 
strips of canvas or sail-cloth, 4 inches wide, arranged as shown 
in fig. 1 (plate iv.), all the bands being strongly sewn together 
at the points where they cross each other. It is intended that 
the bands or end-supports, 6, 6, shall be fastened under the 
bands, a, a, with hooks and eyes similar to those shown in figs. 
8 and 9, so as to admit of raising and lowering either the head 
or the feet, as the case may be, by fastening the hook into a 
higher or lower eye sewn to the bands, a, a. The principal 
dimensions are shown in fig. 1, which represents the support as 
it appears when laid out on the ground. The size represented 
is suitable for use on a hutch 4i feet long, 2 feet deep and 3 feet 
wide. Figs. 2 and 8 show how the stretcher is attached to the 
standards of any bogie, or to the side.s of any hutch in the pit. 
ITie cross-bands, ri, nre aiTanged so as to give support to a man 
of average height and tx) allow of a hammock-formation when 
fastened to its support^s; and, if greater ease be required, coats 
may be flung over the spaces between the bands. The end- 
pieces, 6, 6, for the support, of the head and of the feet, are made 
of somewhat stiffer canvas, and ai*e turned upward so as to assist 
in affording horizontal as well as vertical support. The weight 
of the man stretched out will be sufficient to keep them extended 
a foot or less beyond the main supporting bands, «, a, and at 
the same time give support to the patient. The stretcher is 
intended principally for use with a bogie, and special caps are 
provided for fastening over the standards as shown in figs. 4 aod 
5 : these caps being varied in design to suit the standards of 
different bogies. It may also be used, either with a door-butch 



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A STRETCHER FOR USE IN MIXES. 168 

or with an ordinary hntcli with the ends knocked out, by fasten- 
ing the hooks attached to the bands^ a, a, over the hutch-sides. 
This hook is shown in iigs. 6 and 7. It can also be made avail- 
able for use as an ordinary stretcher by bending the bands, a, a, 
over any long pole, bunton, etc., and attaching the hooks to 
the eye in the back of the band as shown in figs. 8 and 9. 

The advantages claimed for this stretcher as compared with 
an ordinary stretcher are as follows : — (1) It is very much 
easier for the injured person, being of the nature of a hammock ; 
(2) consequently, it does not aggravate many injuries which might 
otherwise become serious ; (3) as a result of this greater ease, the 
bogie can be safely run at a greater speed to the shaft-bottom and 
thus time is saved ; (4) it is easily put together ; (5) it can be 
used with either a hutch or a bogie, or as an ordinary stretcher ; 
(6) it can easily be folded in a small space and carried ; and (7) 
it can be hung on a nail, anywhere, ready for fixing to the bogie. 



Mr. A. Hanley read the following paper on " The Hanley 
Cage Guardian " : — 



VOL. XXXni.-19061P07. 



13 



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164 



THE HAXLEY CAGE GUARDIAN. 



THE HAXLEY CAGE GUARDIAN. 



By albert HANLEY. 



The cage guardian is intended to guard the cage against 
dangers arising from excessive speed, unbalanced forces, jump- 
ing the guides, breakage of guides and breakage of the winding- 
rope, on whatever type of guide and weight of cage it may be 
used. 

In a practical application at Dean 
Lane colliery, Bristol, and other col- 
lieries, the guardian has ridden freely 
at speeds up to 75 feet per second, 
rendered the cage more steady, and 
exerted test-grips varying from 4 
cwts. to 10 tons. Figs. 1 to 4 (plate v.) 
show two sets in practical application 
at Dean Lane colliery. Each set con- 
sists of the parts A, B, C, D, E, F and 
H : the link or chain, Bi or Bj ; the 
weight, H, and the horizontal links 
connecting two or more sets are not 
absolutely necessary. The horizontal 
arm. A, the shackle, D, the shoe, F, 
and the strap, C, form a solid built-up 
rod. The end of the shackle, D, is 
attached to the cage-shackle, I, and 
the shoe, F, moves around, but not on 
the guide, G. The strap, C, attaclies 
the shoe, F, to the arm, A. The arm, 
A, forms a connecting rod joining the 
centre-line of the winding forces to 
the centre of the guide-path. The 
adjustable link, B, is attached to the arm. A, and to the rope, J, 
at any point, 12 inches or more, above the shackle, D, which 




Fig. 5.— Guide-rope, 4 Inches 
IN Circumference, bent by 

THE AcnON OP THE HaNLEY 

Cage Guardian at Dean 
Lane Colliery. 



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THE HANLEY CAGE GUARDIAN. 



165 



may be attached to the cage-chains, the coupling-chain, the rope- 
cap or the rope-pin. The link, B, may be attached to the rope- 
cap, the short coupling, or any other part above the shackle, D. 
The horizontal arm, A, and the link, B, form two sides of a tri- 
angle, the third and guiding side being the rope, J, or other point 
in the centre-line of the winding forces. These parts may be 
made of any thickness or strength. 

On the rope, J, becoming detached, the cage-shackle, T, 
drops upon the shackle, D (fig. 1, plate v.); and because the 
pressure is greater 
on the shackle, D, 
than on the shoe, F, 
the horizontal arm, 
A, assumes a sloping 
angle, and the shoe, 

F, grips the guide, 

G, like a human 
hand (fig. 3, plate v.), 
while the shackle, 
D, acts like a hinge 
(fig. 4, plate v.). 

The amount of 
the grip is dependent 
on and greater than 
the weight of the 
cage. The grip is 
divided into a pull 
on the upper and a 
thrust on the lower 
part of the guides, 
G, when such are 
of the rope, girder, 
rail type ; and 



p^l^B 


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1 






1 


1 1 




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Fio. 6.— Two Sets op the Hanlet Cage Guardian 
ON THE Downcast Shaft, Dean Lane Goijjert. 



when they are of 

wood, H or T iron, 

the pull is prevented by a special design, and thrust only is 

allowed, limited to suit the safe deflection of the particular 

:gmde8, but the friction of the thrust would hold the cage. The 

two sets (fig. 1, plate v.) are so designed and fitted that the 



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166 THE HANLEY CAGE GUARDIAN. 

angle of inclination is limited to a point when the shackles, D^ 
become locked against the cage-shackle, I (fig. 4, plate v.), 
so that the rope-guides shall only be stretched and bent to- 
an amount dependent on the particular guide (fig. 5).* If that 
angle is not sufficient to hold the cage (as in breakages on the^ 
downward journey), the appliance slides on the guide until the 
friction of the downward sliding movement consumes the sur- 
plus energy of the cage. 

As many as eight sets of this appliance may be used on as 
many guides ; or a special safety-guide or guides may be erected, 
and one set of the guardian of suitable dimensions used for the 
cage. 

The appliance does not exert any false grip when a cage is 
dropped slack and picked up rapidly. The pressure, to cause 
grip, must be exercised at the shackle, I) ; and there is no loosen- 
ing action on the bolts. 

The appliance has the peculiarity that, although the horizon- 
tal arm. A, acts as a free rod, as soon as pressure comes on the 
shackle, D, it behaves as if it were a lever ; and practically it acts 
as a lever, without a fulcrum, attached to the cage. There are 
no springs. The appliance is not attached, and at the first part 
of the moment it is independent of the cage, which merelj^ 
tightens the grip sufficiently to hold itself. 

The two sets at Dean Lane colliery (fig. 6) weigh 150 pounds, 
or 35 pounds per ton of loaded cage ; and each set is sufficient to 
hold the cage. The sliding action in a test, 7 feet in IJ 
minutes or 280 feet per hour, slackened as the appliance slid 
down the guide-rope and then the cage stopped. 



* Rope-guideB, similarly bent, have been readily straightened in less than 
30 minutes ; and in one special case, where the stress of the grip was 82 cwts. or 
60 per cent, of the breaking strength of the guide, scarcely a trace of the previous- 
bend was observable. 



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TransacUonsJ^Sd907 



Voi^XXXBL, Tlate Y 



To illustrate'N^AJanl^bIhpero7i''I7i&B<z^^ Guardian ^* 



FiQ. l.-SiDE Elevation. 



FiQ 2.-3E0TI0M SHOWING Grip 
OF Shoe upon a Rope-Quiof 



Fio. 4 -Elevatjon SHOwma Angle 

OP iNCLi NATION OP SHACKLES. 





CI (•;(§») joi.: 



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FiQ. 2.— Plan. 




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jyvtsae^nsJJOe-1907 ^\^\X\z^^OJlXKIX.,PlATEM 

ABa7ReiaACaB^L*flleweauI«t9ea1bmi. — 



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DISCUSSION — ^BOILERS FOR COLLIERY PURPOSES. 167 



THE SOUTH STAFFORDSHIRE AND WARWICKSHIRE 
INSTITUTE OF MINING ENGINEERS. 



GENERAL MEETING, 
Held at the Univsbsity, Bibminoham, April 16th, 1907. 



Mr. F. a. GRAYSTON, President, in the Chair. 

The minutes of the last General Meeting and of Council 
Meetings were read and confirmed. 



The following gentlemen were elected : — 

Member — 
Mr. Jonathan Hunter, Colliery Manager, Cannock, Staffordshire. 

Associate Member— 
Mr. W. DuTF Gibbon, King's Heath, Birmingham. 



DISCUSSION OF MR. F. C. SWALLOW'S PAPER ON 
"BOILERS FOR COLLIERY PURPOSES."* 

Mr. J. T. Onions said that the author had quoted instances 
where the consumption of fuel had been as low as li per cent, of 
the output, and others where the consumption was as high as 
11 per cent. : but both examples were extreme cases, the former 
being exceptionally so. His own experience with boilers of the 
Lancashire type had been an average of 6 per cent., which might 
be said to be a low one for the district. He had recently perused 
a colliery-lease which only allowed a colliery-consumption of 4 
per cent, free from royalty. He desired to ask the author what 
had been his experience with the deposition of mud in the tubes 
and mud-drum of the water-tube boiler, and particularly whether 
mud was deposited in the vertical tubes. 

Mr. S. F. SopwiTH thought that so low a consumption as li 
per cent, could only be attained under the most favourable con- 

* Trans. Inst. M. E,, 1906, vol. xxxiL, page 320. 

VOL. XZZIII.-1906-1N7. H 



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168 DISCUSSION — THE HAXLET CAGE GUARDIAN. 

ditions, Buch as tHiose where coking coal was manufactured into 
coke and the boilers were fired by the gases drawn from the 
ovens. His own experience in the Cannock Chase district had 
been an average all the year round of about 8 per cent, on an 
output of 500,000 tons per annum — in summer (when the output 
was less) from 9 to 10 per cent., and in winter from 5 to 6 per 
cent. 



DISCUSSION OF MR. A. HANLET'S PAPER ON "THE 
HANLET CAGE GUARDIAN."* 

Mr. Albert Hanley exhibited and described his cage 
guardian, an appliance designed to guard against accidents to 
the cage from the breaking of the winding-rope. Recent acci- 
dents proved once more how it behoved coUiery-ofiicials to take 
every precaution for preventing loss of life ; and there was a 
possibility of hasty and restrictive legislation unless such acci- 
dents were prevented. 

The President (Mr. F. A. Grayston) said that the Hanley 
appliance appeared not to act too quickly, as was the case in some 
appliances designed to prevent winding accidents. He con- 
sidered that the invention should be put to more practical and 
thorough tests, under ordinary working conditions, than had yet 
been made. He was inclined to think, if the rope were to break 
near the surface when the cage was at any depth, that the conse- 
quences would be serious, owing to the heavy weight of rope 
falling upon and around the cage and appliances, before the 
latter had time to suspend the cage. 

Mr. S. F. SoPWiTH asked what was the actual greatest stress 
on a rope-guide that had been recorded on the breaking of the 
rope on the downward journey, and whether existing guides^ 
which were not fitted for that purpose, were sufficient to with- 
stand the additional strain? 

Mr. Hanley said that it did not follow that the shoe of the 
appliance stopped where it fijrst gripi)ed; and in one test it 
slipped 7 feet in 1^ minutes. The shoe touched the guide, when 
2 degrees out of the perpendicular, and commenced to grip when 

♦ Trans, Inst. M, E,, 1907, vol. xxxiii., page 164. 



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DISCUSvSION — THE HANLEY CAGE GUARDIAN. 169 

it became 6 degrees. The movemeat and grip of the appliance 
was not a sudden fall and a sudden grip at the stopping position. 
When the rope was detached, the cage-shackle, I, and the cage- 
weight pressed on the shackle, D, causing the arm, A, to move in 
an increasingly inclined position, the motion gradually slacken- 
ing and retardation gradually increasing till the cage and the ap- 
pliance stopped.* The point of stoppage and the distance of sliding 
on the guide depended on the cage-weight and the character of the 
guide. The distance of eliding on the guides could be lengthened 
or increased relatively, but sliding was allowed in practice so as to 
enable the appliance to utilize the kinetic energy of down-break- 
ages. He did not think that a broken rope, even if 500 feet 
long, would interfere with the safety of the appliance, as the 
apparatus tended to throw it on one side and it would then ioll, 
to some extent, clear of the cage. The tests had been made with 
a detaching-hook to sever the rope. The greatest stress on a 
guide had -been 10 tons. A special guide could probably be 
fitted for use with heavy cages, where it was not desirable to use 
the working guides for safety purposes. A special safety guide 
would prevent any excessive lateral swing of the cage if a work- 
ing guide were broken ; and it could be used to replace, tempor- 
arily, the broken guide. The use of a special safety guide would 
provide extra stability to the cage, especially in the case of long 
cages sliding on wood or iron guides. 

Ml'. Alexander Smith said that he had great sympathy with 
inventors, as they had considerable difficulty in putting an inven- 
tion of this kind to a proper practical test, coUieiy owners being 
very unwilling to carry out experiments and tests with their 
plants under working conditions. There was certainly one good 
feature about the apparatus, namely, that it was slow in action : 
the fault of similar safety-appliances being their sudden action, a 
remedy almost as bad as the disease. 



Trans. Insi. M. E,, 1907, vol. xxxiii., page 165. 



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170 DISCUSSION — LIQUID AIE AND ITS USE IN RESCUE- APPAEATUS. 



MANCHESTER GEOLOGICAL AND MINING SOCIETY. 



GENERAL MEETING, 

Held in ths Rooms of thk Sociktt, Queen's Chambers, 

5, John Dalton Street, Manchester, 

February 12th, 1907. 



Mr. CHARLES PILKINGTON, President, in the Chair. 



The followiag gentlemeii were elected, having been pre- 
viously nominated: — 

Member — 
Mr. Henrt Batson Beales, Mechftnical and Electrical Engineer, 64, Cross 
Street, Manchester. 

Associate Member — 
Mr. Friedrich Schember, 9 Liechtenstrasse, Vienna. 



DISCUSSION OF MR. OTTO SIMONIS' PAPER ON 
"LIQUID AIR AND ITS USE IN RESCUE- 
APPARATUS."* 

Mr. Otto Simonis (London) demonstrated and explained the 
aerolith, a liquid-air rescue-apparatus. He (Mr. Otto Simonis) 
was not a mining* engineer, but a fire engineer; and it was for 
the purpose of combating smoke that the apparatus was first 
designed. The apparatus was now used at Baron Rothschild's 
coal-mines in Austria, and by the London Fire Brigade. At 
Baron Rothschild's mines, a plant had been installed at a cost 
of £1,400 for the production of liquid air; about 5 gallons 
per hour were made, and in addition compressed oxygen was 
produced with the same plant. This plant proved to be not too 
big, as they had found employment for the liquid air in a variety 
of ways. 

The President (Mr. Charles Pilkington) expressed the fear 
that the aerolith apparatus would easily get damaged when 
• Trans. Inst. M. E,, 1906, vol. xxxii., page 534. 



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DISCTJSSIOX — LIQUID AIR AXD ITS USE IN RESCUE- APPARATUS. 171 

worn on the back; because, in a mine after an explosion, the 
wearer would have to crawl on his hands and knees, and the 
knapsack or bag would be rubbed against the roof. He sug- 
gested that the clock, placed at the top, and intended to warn 
the wearer when the stock of liquid air was nearly exhausted, 
might be placed, if possible, in a less exposed position. 

Mr. Otto Simoxis replied that the bag was not an essential 
part of the apparatus, as it could be removed, and the apparatus 
would still work efficiently. He, however, preferred to use the 
bag, as it afforded an auxiliary reservoir for extraordinary cases. 
The man who was using the apparatus would become aware in 
due time of his danger, by feeling the bag and by the diminution 
of the volume of air passing through his lungs. 

Mr. John Gerrard (H.M. Inspector of Mines) asked what 
quantity of air was left in the knapsack after the clock had 
given warning. 

Mr. Otto Simonis said that the wearer could set the clock 
to give warning when the supply waa half done, or when it 
would be exhausted in another half-hour. Bottles filled with 
liquid air could be taken into the mine and kept there for use 
in emergencies. 

The President (Mr. Charles Pilkington) said that he had 
seen many appliances designed for rescue-purposes. He was 
a member of a committee which had to deal with this particular 
subject, and there were possibilities in this apparatus that, in 
his view, were almost better than anjrthing else he had seen. 
He was favourably impressed with it, but he wanted to see it 
tested in rough work. The aerolith apparatus was very much 
lighter than other kinds, and he hoped to see it severely 
tested at one of the rescue-stations. He thanked Mr. Simonis, on 
behalf of the members, for giving this demonstration of its use. 

Mr. George H. Winstanley, in moving a vote of thanks to 
Mr. Simonis, said that he had for a long time taken a deep 
interest in the question of rescue-apparatus and read a paper 
ten years ago before the Society in which, curiously enough, he 
strongly advocated the establishment of properly-equipped 



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172 DISCUSSION — LIQUID AIR AND ITS USE IN RESCUE- APPARATUS. 

rescue-stations throughout the coal-fields of Great Britain.* The 
aerolith apparatus struck him as having features which strongly 
recommended it as a practical appliance. The great difference 
between it and many other appliances was its simplicity. The diffi- 
culty hitherto had been to dispose satisfactorily of the carbon 
dioxide, which tended to increase in quantity in the initial 
volume of air that was breathed over and over again with 
additions of oxygen. In this apparatus no attempt was made to 
breathe the same air again ; a great advantage would be found, 
too, in the easily portable character of the bottles of liquid air 
as against the large steel cylinders of oxygen for replenishing 
the apparatus in actual use. The former (the bottles of liquid air) 
could more easily be taken into the mine, and carried forward to 
some convenient place for the purpose of replenishing the knap- 
sack when necessary; and consequently the rescue-party could 
carry on their work for a longer period, with less anxiety as to 
their supply of respirable air. 

Mr. John Gerrard (H.M. Inspector of Mines), in seconding 
ihe motion, said that he was not going to commit himself to 
anything more, than to say that, theoretically, the aerolith 
apparatus appeared to have advantages over the oxygen principle 
on which other systems depended. He preferred to wait, before 
pronouncing a definite judgment, until the apparatus had been 
tested at one of the rescue-statioms ; and he sincerely hoped that, 
before very long, they would have a station in Lancashire where 
they could prove whether this apparatus was practicable or not. 
Their President was the chairman of the committee that was 
working for this end, and it was very desirable that its labours 
should soon be successful. He thought that such an appliance as 
this might be useful in dealing with underground fires. He held 
very strongly that there was a field for such apparatus. For- 
tunately, they did not now have in Lancashire disastrous explo- 
sions ; but they were constantly having to deal with underground 
fires, and they had had, in the last few years, several disastrous 
underground fires which had been most diflicult indeed to deal 
with. It seemed to him that, apart from explosions, there was 
a field for the use of these appliances in dealing with the extinc- 

• TranMctions of the Manchester OeologiccU and Mining Society , 1897, voL 
XXV., page 148. 



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DISCUSSION — LIQUID AIB AND ITS USE IN RESCUE-APPARATUS. 173 

tion of underground fires. He was sure that they were all veiy 
grateful to Mr. Simonis for coining to MaiLchester, and giving 
to the Society so full an explantion, because the people of 
Lancashire liked to be in the van of progress. 

The motion was cordially adopted. 

Mr. Otto Simonis said that he did not claim that his apparatus 
was perfect in every detail, such as the type of mouthpiece, etc., 
and therefore he welcomed any suggestions. He had always held 
that the resoue-^ppliances hitherto in use possessed drawbacks 
which were absolutely against them from a practical point of 
view. The weight and complication were fatal disadvantages, 
independently of the fact that there were certain dangers in the 
use of caustic soda and other chemicals. 



Mr. Thomas H. Wordsworth read the following paper on 
Cage-lowering Tables at New Moss Colliery": — 



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174 CAGE-LOWEBING TABLES. 



CAGE-LOWERING TABLES AT NEW MOSS COLLIERY. 



By T. H. WORDSWORTH. 

When pits were shallow and only single-decked cages were in 
use, there was no need for cage-lowering tables; but, as they 
became deeper, the extra length of time spent in winding, coupled 
with the great weight of the rope compared with the load lifted, 
led colliery owners to adopt larger cages. As the size of the pits 
rendered it impossible to put more tubs on a deck, cages with 
two, three, four and up to six decks were used. 

Where two-decked cages only are used, duplicate landings 
may be put in both at the surface and underground, and a 
double set of men may be employed ; and this reduces the period 
of decking to a minimum. In other cases, keps are put in at the 
pit-bottom; and, by carefully adjusting the ropes, the tubs for 
each deck are changed simultaneously at the top and the bottom. 
This system has the disadvantage that, if any hindrance takes 
place at the top or bottom of Iha shaft, both sets of men are 
stopped and the length of time occupied in changing is con- 
siderably increased ; besides which, the engineman needs a signal 
from the top and bottom for each deck, and, should he slightly 
overrun, the cage is likely to be damaged. 

The first cage-lowering table seen by the writer was at the 
West Riding collieries, Normanton, although he believes that 
they were originally used in Lancashire. The table in use at 
the West Riding colliery was balanced by weights hanging in 
a small pit, half of these being hung on the end of the rope and 
the other half supported on a stage, so that they were picked up 
after loading the second deck of a four-decked cage. The use 
of these supplementary weights, whilst reducing the necessary 
brake-power, caused complications when winding men, and it 
was only possible to ride men on two of tile decks. 

The tables now in use at New Moss colliery have been 
evolved from this : they are so arranged that it is possible to lower 



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Cage-lowering tables. 175- 

the empty cage and table, and in this way men can ride on all 
the decks. The balance-weights have been taken out of the 
pit and put in sight. The apparatus may be divided into three 
parts: — (1) The table on which the cages alight ; (2) the brake- 
arrangement for giving the hooker-on control of the tackle ; and 
(3) the balance-weights for bringing back the table when the 
cage is lifted from the bottom. 

The table is biiilt of steel joists and channels (figs. 1 and 2, 
plate vi.). The main frame of the table, A, is formed of two 
main longitudinal joists, a and 6, 13 feet 3 inches in length, 9 
inches deep, 4 inches wide and ^ inch thick, connected at each 
end by two cross joists, c, d, e and f, of the same section, trimmed 
in and secured by steel angle-irons and rivets, 18 inches from 
the end. This frame is further strengthened in the centre 
by steel channel-irons, g and A, 3^ inches wide and 9 inches 
deep, placed back to back ; and four short joists, i, j, k and I, 
trimmed into these and the end joists form the opening for 
the balance-rope. There are also four short channel-iron 
distance-pieces, m, n, o and p. Four battens, q, r, s and t, 
12 inches wide and 3 inches deep are placed longitudinally on 
this table, so as to form a cushion between the steel cage and 
the steel table and save wear on the bottom of the cages. 

The table. A, is carried by two steel-wire ropes, B and C, 1^ 
inches in diameter, passing over two pulleys, D and E, 4 feet in 
diameter, resting on girders running across the pit-bottom. The 
attachment between the table and the ropes has been arranged 
so that, by taking out two pins, u and v or w and »r, at either 
end of the tabled it can be slung from the other rope and hung 
clear of the cages. In case of cleaning out the sump or of 
changing the weights, F and G, on the end of the conductors, 
H, or for any work done below the table, this is a great 
advantage. 

The other ends of the ropes, B and C, after passing round two 
surge-wheels, I and J, 4 feet in diameter (similar to endless- 
rope haulage-wheels), and over two pulleys, K and L, 4 feet in 
diameter, placed about 20 feet above the floor, are attached to 
steel balance-boxes, M and N, built of angle-irons (3 inches 
wide, 3 inches deep and ^ inch thick) and plates ^ inch thick. 
The attachment is made by short sockets, a, with pins, 6, passing 
through cross bars, e, inside the boxes. These boxes are filled 



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176 CAGE-LOWERING TABLES. 

vith small scrap-iron, such as chain, bolts, etc., and run in angle- 
iron slides, d, e, f and g. 

The brake-wheel, 0, 6 feet in diameter and 9 inches wide on 
the face, together with the two surge-wheels, I and J, is keyed 
on to a shaft, P, 6 inches in diameter, supported by six pedestals, 
«, h, c, d, e and f. The brake is of the double-post pattern, with 
compound levers, ai, ed, de, fg, ghi, hjy il and Id, the leverage 
being about 400 to 1 ; and wooden brake-blocks, m and n, are 
used, aa they have been found to give the best results. The 
weight of the levers is balanced by a weight, g, attached to a 
chain, passing over the pulley, p. 

In working, the winding-engineman drops the cage, Q, on 
the table. A, which is then in the top position, and at the same 
time puts the top cage on the keps at the surface. The tubs are 
then changed in the bottom-deck, and, when the brake-lever is 
lifted, the weight of the cage, Q, is sufficient to overcome the 
balance-weights. The hooker-on is then able to stop the cage, 
with the brake, when the second deck comes level with the land- 
ing-plates ; and, so on, until all the decks are loaded and the 
cage and the table are in the position shown in fig. 2 (plate vi.). 
In this way, by having a small amount of chase or slack on the 
winding-rope, the hooker-on at the bottom of the shaft is enabled 
to change his tubs practically as quickly as the change is made 
on the surface, and no signal is necessary until all the decks are 
changed and the cage is ready for sending to the surface. 

After the cage leaves the bottom, the table is brought back 
to the top position by the balance- weights. 

Too much chase or slack, however, should not be allowed on 
the winding-rope, aa this is objectionable when picking up, and 
there is also a danger of the detaching-hook coming on the cage- 
top or down the cage-iide, should there be any delay in changing 
the tubs at the pit-bottom. This difficulty may be overcome by 
using cage-chains, 10 to 12 feet long; and, with decks only 4 
feet deep, it is then possible for the surface-man to deck the 
whole of the decks of the cage before the detaching-hook 
falls over the cage-side. On one occasion, when there was too 
much chase or slack on the rope, the detaching-hook became 
twisted in the cage-chains, and sheared the copper pin instead of 
lifting the cage from the bottom. 



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The InsUUtjUon^ ofMuUrig Enqwu,ers. 
TransacliortsJS0SlS07. 



Voz.XSX/11, Plate W. 
T^les otMwMoss CblUer y!' 




27ia Jfanaheeear Oe^lo^ioaZ and. ATijia 
TraJiaacUo7isl906]9C7. 



U\^\Xy2M^^I'^SXZ.,PLATEllI. 



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DISCUSSION — CAGE-LOWEBING TABLES. 177 

Old winding-ropes may be used for working the tables, but 
experience will show, in each case, whether this is the better 
policy. The writer prefers to use a special flexible rope, as it 
reduces the liability to stoppage during working hours ; and one 
rope will la«t three or four years. In cases of overwinding, the 
table has the advantage that the shock to the bottom cage is 
considerably reduced. If men were in the cage there would 
be less liability of their being injured ; and it has also been found 
that the life of the cages is considerably lengthened. 

In case of accident or breakdown of any portion of the tackle, 
the table can be placed in the bottom position, as shown in 
fig. 2 (plate vi.) and winding continued until the end of the 
shift or such time as the repairs can be finished. But if the pit 
has been previously fully occupied in winding, the reduction of 
the output would vary from 10 to 20 per cent. 

It is not suggested that cage-lowering tables should take the 
place of hydraulic decking-cages, with simultaneous changing 
for all decks, but there are many instances in faulted and steep 
districts or thin seams, where it is practically impossible to get 
sufficient coaJ to the pit-bottom to keep the winding-engine 
working full time and so afford a return on the capital neces- 
sary to instal hydraulic decking-plant. The writer is of opinion 
that, where three or four decks are used and the output does not 
warrant an expenditure on simultaneous changing plant with 
balance-cages, the cage-lowering table is the best means of 
dealing with three or four decked cages, especially if a spiral 
drum be used, as it reduces the number of signals to a minimum 
and leaves the top and bottom of the shaft practically 
independent of each other. 



The President (Mr. Charles Pilkington) expressed the obli- 
gation of the members to Mr. Wordsworth for his paper and the 
accompanying drawings. It was, no doubt, an important 
apparatus that Mr. Wordsworth had described, and one that 
saved a great deal of time in decking. There were several 
appliances, very similar in character, in use at the Clifton and 
Kersley collieries, with which he himself was associated ; but in 
the latter case a chain was used, instead of a rope. 



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178 DISCUSSION — CAGE-LOWEEING TABLES. 

Mr. Geoege B. Haeeison (H.M. Inspector of Mines), in mov- 
ing that the thanks of the members be accorded to Mr. 
Wordsworth, stated that he did not remember having seen an 
apparatus like the one described by Mr. Wordsworth before he 
came to Lancashire, where, at some pits, there were as many as 
six decks in the cages, and this apparatus afforded great advan- 
tages, particularly to the engineman, who was thereby relieved 
of a great strain. 

Mr. G. H. WiNSTANLEY, in seconding the motion, remarked 
that the apparatus described by Mr. Wordsworth included new 
details and improvements, which had considerably enhanced the 
value and interest of his paper. The members present had been 
interested, and the drawings clearly demonstrated the advan- 
tages of the apparatiis. 

Mr. T. H. WoEDSWOETH said that, if the winding-ropes were 
properly adjusted, there was no trouble with them. 

The motion was cordially adopted. 



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TRANSACTIONS. 179 



THE NORTH OF ENGLAND INSTITUTE OF MINING 
AND MECHANICAL ENGINEERS. 



GENERAL MEETING, 

Held in the Wood Memobial Hall, Newcastle-upon-Tyne, 

April 13th, 1907. 



Mb. J. H. MERIVALE, President, in the Chair. 



The Seceetaby read the minutes of the last General Meeting 
and reported the proceedings of the Council at their meetings 
on March 22nd and that day. 



The following gentlemen were elected, having been previously 
nominated: — 

Members— 
Mr. Thomas Abnold, Civil and Mining Engineer, Castle Buildings, Llanelly. 
Mr. Simpson Cbombis, CoUiery Manager, Banks House, Durham. 
Mr. ALT.AN Abthub Davidson, Mining Engineer, c/o Mr. F. F. Fuller, 

138, Salisbury House, London, E.C. 
Mr. WiLUAM Dick, Consulting Engineer, 190, Palmerston House, Old Broad 

Street, London, E.C. 
Mr. Lionel Asheb Jacobs, Colliery Manager, E. I. R. Collieries, Giridih, 

Bengal, India. 
Mr. Evan Jones, Quarry Manager, Bryn Golen, Station Road, Festiniog, 

Blaenau Festiniog. 
Mr. Henby Stuabt Mabtin, Mining Engineer, Trewem, Dowlais. 
Mr. Lbbebbcht Fkbdinand Richard Schnabrl, Consulting Mechanical 

Engineer, Salisbury Buildings, 443, Bourke Street, Melbourne, 

Victoria, Australia. 
Mr. Daniel Sneddon, Colliery Manager, 73, Scott Street, Newcastle, 

New South Wales, Australia. 
Mr. Neil Taylob, Mechanical Engineer, 58, Frederick Street, Loughborough. 
Mr. Isaac Williams, Mining and Quarrying Engineer, Elterwater, Amble- 
side. 
Mr. RoBEBT Wood, Colliery Manager, 8, Olympia Gardens, Morpeth. 



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180 DISCUSSION — NEW APPARATUS FOR RESCUE-WORK IN MINES. 
ASSOCTATE MkMBEB— 

Mr. Hans von Lovwevstein zu Loewenstbik, Friedrichstrasse, 2, Essen- 
Ruhr, Germany. 

Associates— 

Mr. Thomas Bates, Under-manager, West Wylam Terrace, Prudhoe, Oving- 
ham, S.O., Xorthumberland. 

Mr. Chbistopheb Robinson, Back-overman, Dudley Colliery, Dudley, S.O., 
Northumberland. 

Mr. Robert Wabdle, Under-manager, Edgewell Terrace, Prudhoe, Oving- 
ham, S.O., Northumberland. 

Mr. FosTEK Williams, Assistant Mine- and Quarry- manager, Rothay Cottage, 
Grasmere, S.O., Westmorland. 

Mr. Geobob Wood, Back-overman, Dudley Colliery, Dudley, S.O., North- 
umberland. 

Students— 
Mr. Ebnest Hodgson Kibkup, Mining Student, Peases West Collieries, 

Crook, S.O., County Durham. 
Mr. Thomas Edwabd Slateb, Mining Student, Blaydon Burn Colliery, 

Blaydon-upon-Tyne, S.O., County Durham. 

SUBSCBIBER— 

Rand Mines, Limited, The Corner House, Johannesburg, Transvaal. 



DISCUSSION OF MR. W. E. GARFORTHS PAPER 
ON **A NEW APPARATUS FOR RESCUE-WORK 
IN MINES."* 

Mr. W. C. Blackett said that, from what he had seen of 
rescue-work at collieries, he thought that the so-called rescue- 
appliances would seldom come into use. He could not remem- 
ber a single instance in which he would have felt safer if he 
had been provided with such an apparatus, or any instance 
where he thought a single life could have been recovered by 
such means. He was, however, bound to say that instances 
could arise, but it would be very seldom indeed ; and, if they did 
arise so very seldom, then he was afraid that, in the course of 
years, the use of the apparatus would not be sufficiently practised 
or persisted in. Therefore from that very fact, when called 
upon, it would very likely constitute a source of danger. It did 
not seem to him that such apparatus should be lightly used. 
He would not like to go into any mine, for the purpose of 
exploration after an explosion, with the intention of putting on 

• Trans, Imt, M, E,, 1906, vol. xxxL, page 625. 



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DISCUSSION — ^NEW APPAUATITS FOR EESCUE-WORK IN MINES. 181 

a headgear, unless lie was certain that life was to be saved only 
in this way; and he thought that was the attitude that should 
be assumed. The use of such apparatus merely for the sake of 
re-establishing ventilation would risk a valuable life, if anything 
went wrong while the wearer was out of immediate reach, amid 
irrespirable gases. If it were known that a person was in 
a known place and could be reached in a certain time, under 
those circumstances an apparatus of this kind would be extremely 
useful ; but the difficulty he foresaw was that men would get 
out of practice in its use, and he thought that if they were 
to establish anything in the nature of rescue-stations and appli- 
ances (as he hoped they would), they must be extremely careful 
that the means they used were such that they would be constantly 
kept in practice, and with a sort of discipline, which he feared 
they were not likely to get at collieries. 

The President (Mr. J. H. Merivale) said that, at the invita- 
tion of Mr. W. E. Garforth, he and some other members of the 
Institute had visited the rescue-station at Altofts collieries, and 
he was favourably impressed with it ; but he came to the conclu- 
sion that persons must be specially trained in the use of rescue- 
appliances. Mr. Blackett had pointed out that he would not 
like to use the apparatus unless there was some strong reason; 
but he would go further than Mr. Blackett, and would not put 
it on, under any circumstances, until he had had previous prac- 
tical training in its use. Mr. Garforth was of opinion that there 
should be a rescue-station in each district ; for instance, in New- 
castle-upon-Tyne for Ihirham and Northumberland. A number 
of men should be trained, and each man should have his own 
apparatus that would fit him in the same way as his clothes did. 
Such men, so fitted and trained, would be, humanly speaking, 
absolutely safe in irrespirable gases, and could do hard work for 
t\ro or three hours. These appliances were liable to get out of 
order ; but if they were stored in a central rescue-station in New- 
castle-upon-Tyne, under a trained man, they could be kept in 
order ready for use when necessary. He hoped that colliery- 
owners in their district might do something towards carrying 
out such an arrangement. 

Mr. W. C. Blackett said that he was not prepared to agree 
that even men who were practised in the use of rescue-appliances 



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182 DISCUSSION — ^NEW APPABATUS FOR EESCUE-WORK IN MINES. 

could put them on their heads and shoulders and be perfectly and 
absolutely safe. It struck him veiy forcibly, in reading the 
account of the recovery of the Courriires collieries, that not a 
single life was saved by the use of the apparatus and equally 
strongly that one life was lost. An unfortunate man, who was 
wearing the apparatus, was killed, and the helmet, torn off his 
head, was found lying by his side. This result showed that it 
was not to be accepted without reserve that men were perfectly 
safe when using such appliances. If rescue-appliances must be 
provided, he was prepared to suggest how that could be effected 
for Durham and IN" orthumberland. It was very probable, even 
if men were specially trained, that untrained persons would be 
required to put on the apparatus : if a body of trained men went 
to a colliery after an explosion, they could not be turned loose 
in the pit without somebody to guide them, and that might be a 
person familiar with the workings, who might not have had 
-any experience of rescue-appliances. 

Mr. Henry Lawrence said that if it were granted that they 
could find an apparatus which answered all purposes for saving 
life without the present encumbrances, it was a very poor argu- 
ment to advance that, after a time, the apparatus would got out of 
date, or would not be kept in proper order for work. 

Mr. T. E. Forster said that he had an open mind on the 
matter, but until somebody showed that there was more 
necessity for the use of such appliances than was evident at 
present, he did not think that it would be desirable to provide 
them. He had been connected with the mines of Northumber- 
land for many years, and could not recollect a case where such 
appliances were required, except at Killingworth colliery, where 
the Fleuss apparatus was used. The difficulty there was not, 
however, in getting out those who were unprovided with the 
apparatus, but in rescuing the man who was wearing it. 

The President (Mr. J. H. Merivale) remarked that the man 
who was killed at the Courrieres collieries was not accustomed to 
the use of the appliance. 



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DISCUSSION — ^EXPLOSION AT WINGATE GRANGE COLLIEEY. 188 

DISCUSSION ON THE EXPLOSION AT WINGATE 
GRANGE COLLIERY.* 

Mr. Donald M. D. Stuart (Bristol) wrote that the Reports 
presented a lucid description of the explosion, with perfect 
agTeement as to its ori^n ; and contained valuable evidence for 
discussing the causes of the disaster. The explosion evidently 
originated in coal-dust in the main intake-airway where over 
26,000 cubic feet of air was passing per minute, and where gas 
could have no existence. Explosions of gas had been so exhaust- 
ively investigated that the conditions were known, and remedies 
were available in ventilation and safety-lamps that made such 
explosions preventible ; but the dangers of coal-dust were not so 
well known. It was true that evidence had been accumulating 
for several years showing that the coal-dust deposited in mines 
was capable of originating and propagating explosion ; but where 
there had been long experience of immunity from explosion in 
circumstances supposed to be favourable to coal-dust ignitions, 
it was still difficult for many to realize that explosion could be 
caused by cooj-dust alone. Wing^te Grange colliery, for example, 
had been worked for over 40 years without any explosion or 
ignition of coal-dust; and in recent years changes had been made 
in the ventilation and explosives, that were supposed to enhance 
its safety : consequently no apprehension existed that there was 
danger in the coal-dust. The danger now stood disclosed by 
the explosion, and on evidence of fact so complete that, supple- 
mented as it was by the records of similar disasters, the 
mining world might be fairly asked to accept the fact that coal- 
dust was an explosive agent. 

Many interesting questions arose, and amongst them the en- 
quiry whether the coal-dust possessed explosive properties during 
the 40 years of immunity from explosion, or whether they were of 
recent development; it might be useful to consider the circum- 
stances that were reported. The effect of air-currents sweeping 
through haulage-roads had been often observed, and here the 
moisture must have been largely absorbed in a period of 40 
years ; but in some mines both deposition of coal-dust and with- 

• Reports to His Majesty's Secretary of State for the Home Department on 
the Ciraimstances attending an Explosion which occurred cU Wingate Orange 
Colliery, Wingate, on the 14th October, 1906, by Mr. A. H. Ruegg, K.C., and 
Measrs. R. D. Bain and J. B. Atkinson, M.Sc., two of H.M. Inspectors of Mines, 
1907 [Cd. 3379]. 

TOL. XXXni.-lS06.1907. 15 



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184 DISCUSSION — ^EXPLOSION AT WINGATE GRANGE COLLIERY. 

drawal of moisture were ^adual, and might extend over many 
years before the danger-stage wa« reached. It also appeared that 
up to a recent year the mine wba adequately ventilated by a fan 
producing 102,000 cubic feet of air per minute;* but subse- 
quently the new fan had yielded nearly twice the quantity, 
namely, 193,478 cubic feet.t If this increased quantity of air 
was taken through the original intake-airways, the velocity of 
the currents must have been considerably raised, accelerating the 
absorption of moisture, increasing leakage from the tubs, and 
adding to the coal-dust deposits in the haulage-roods. One 
effect of the increased ventilation would therefore be dry intake- 
airways and a more abundant supply of coal-dust; another, the 
increased sensitiveness of coal-dust after exposure to aii*-curpents, 
which had been observed by Prof. P. P. Bedson. These circum- 
stances suggested that the explosive properties of the coal-dust 
might have been of recent development, and this was consistent 
with the fact that the explosion occurred after the changes in the 
ventilation. 

He (Mr. Stuart) had found similar circumstances in his invest- 
igations of the explosions at the Camerton and Timsbury col- 
lieries. Both mines had been worked with immunity from 
explosion for from 70 to 100 years; but the ventilation was 
largely increased with no alteration in the dimensions of the 
intake-airways, whereupon explosive properties developed in the 
coal-dust distributed in the haulage-roads, and extensive explo- 
sions occurred. 

The ventilation of mines had claimed principal attention in 
past legislation, with limitation of view to dilution and removal 
of gas ; but ihe time had now come when another factor of even 
more disastrous energy had to be considered, since it was evident 
that while large quantities of air, necessarily travelling at high 
velocity, would dilute and render harmless noxious gases with a 
large margin of safetv, they at the same time developed a more 
serious danger in creating explosive conditions throughout the 
main arteries of the mine, that needed only kindling at one point, 
to traverse the whole. 

♦ Reports to His Majesty*s Secretary of State for the n<yme Department on 
the Circumstances attending an Explosion which occurred at Wingate Orange 
Colliery, Wingatey on the 14th October , 1906, by Mr. A. H. Ruegg, K.C., and 
Messrs. R. D. Bain and J. B. Atkinson, M.Sc, two of H.M. Inspectors of Mines, 
1907 [Cd. 3379], page 16. 

t Ibid,, page 17. 



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DISCUSSION — ^EXPLOSION AT WINGATE GRANGE COLLIEEY. 185 

Considerable labour bad been spent for many years in tbe 
almost bopelees mission of obtaining explosives that would not 
ignite gas or coal-dust in mines ; the subjects of dust^tight tubs 
and watering haulage-roads were now receiving much attention^ 
but the potent relations of air-currents to the coal-dust question, 
appeared to have been overlooked. With air-currents at velo- 
cities of 400 to 800 feet per minute, and loaded tubs travelling 
in the opposite direction at equal speeds, depositions of coal-dust 
along the arteries of the mine, and development of explosive pro- 
perties in the dust, appeared to be almost unavoidable; and he 
(Mr. Stuart) suggested that regulation of the ventilation to 
remove noxious gases with least effect in creating dangerous 
coal-dust) claimed serious attention. 

The disaster threw further light on the behaviour of explo- 
sives when used in practical conditions ; it was well known that 
detonating permitted explosives had failed to ignite coal-dust 
in the large number of tests and experiments made in this 
country, and the permitted explosives were supposed to possess 
a high degree of safety ; it was recorded here that '* a permitted 
explosive was only used as an extra precaution " ; * but this 
explosive unfortunately caused an explosion with coal-dust, 
although such an event had not happened with all the previous 
shot-firing. It was true that the explosive was not used aa 
required by law ; but it was used by a competent shot-firer, who 
had evidently been misled by the reports that detonating explo- 
sives could not ignite coal-dust. It was also true that the explo- 
sive should have been used in a properly drilled hole ; but the 
same class of explosive was used in holes at Albion colliery, and 
ignited the coal-dust with an awful result. The doctrine was 
still taught that a detonating explosive was the safer, because 
its products expanded with lightning-like rapidity, and conse- 
quently cooled down before they could ignite gas or coal-dust. 
This theory was answered by the Wingate Grange explosion 
with its fatal record. 

There were several very interesting observations on the propa- 
gation of the explosion. The men killed by violence were at 

♦ Reports to His Majesty's Secretary qf State for the Home Department on 
the Cireumstanoes attending an Explosion which occurred at Wingate Grange 
Colliery, Wingaie, on the 14th October, 1906, by Mr. A. H. Ruegg, K.C., and 
Messrs. R. D. Bain and J. B. Atkinson, M.Sc., two of H.M. Inspectors of Mines, 
1907 [Cd. 3379], page 18. 



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186 DISCUSSION — ^EXPLOSION AT WINGATE GRANGE CX)LLIEEY. 

places distant from each other, and it was not quite clear whether 
the authors suggested that the violence was due to a force rush- 
ing through the field of explosion, or to the sudden development 
of force where the men stood. It would be very useful if further 
information could be given on this point, and bearing upon the 
development of violent action also at the top of the drop staple. 
It was recorded that there were indications of force " between the 
shafts and the stable- way junction and in-bye of the junction ; 
then, extending about 270 feet, there was a distinct length of road 
on which, although there were things to disturb, no disturbance 
had taken place ; beyond the undisturbed length evidences of a 
renewal of disturbance were apparent."* It would be useful to 
know the actual position of this space of repose : the stable-way 
junction was marked at 720 feet from the shaft, and the shot 1,308 
feet beyond the junction ; while the shot-firer was found some 
42 feet from the shot, bearing marks of violent forces. It was 
also shown that propagation failed a short distance beyond the 
stable way, and at 2,700 feet from the junction, in the north- 
east way; at the latter point abundant deposits of coked dust 
were observed, presumably, therefore, the propagation did not 
fail for want of coal-dust. It would promote the discussion of 
this subject if further light could be thrown on the places of 
failure of propagation, and the causes. 

The action of Edward Murton (master shifter) and William 
Peat (examiner) deserved to be chronicled ; and, if what they 
did could be embodied in " Pit Stories," for circulation amongst 
miners generally, such intelligence, self-reliance and courage 
would have far-reaching effects in keeping that standard to the 
front, and must have an educational value in the accidents of 
mining. 

He (Mr. Stuart) would like to join with the members in an 
appreciation of this valuable contribution by the authors on 
the subject of colliery explosions. 

Mr. Philip Kirkup (Birtley) wrote that the evidence was 
unanimous in proving that fire-damp did not enter into the 
cause, no gas ever having been reported and the point of origin 

• Reports to His Majtsttfs Secretary of State for the Home, Department on 
the Circumstances attending an Explosion which occurred at Wingate Orange 
Colliery, Wingate, on the Uth October, 1906, by Mr. A. H. Ruegg, K.C., and 
Messrs. R. D. Bain and J. B. Atkinson, M.Sc, two of H.M. Inspectors of Mines, 
1907 [Cd. 3379], page 24. 



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DISCISSION — ^EXPLOSION AT WINGATE GEANGE COLLIERY. 187 

being one that was very unlikely to harbour any. The evidence 
wafl also very strong, to prove that the explosion was caused 
entirely by an ignition of coal-dust and air, and originated from 
flame due to a charge of geloxite being fired on a projecting 
ledge of rock, probably covered by a mixture of grease and coal- 
dust. The roadways were described as not particularly dusty, 
proving that it was the very finest particles of dust that were 
dangerous — those which were most likely to be unobserved, such 
aa would rest on the top of baulks and props, etc. It did not 
therefore appear that brushing the sides, roof, etc., would be 
advantageous, unless effective watering was carried on at the 
same time, to prevent the finer particles, thus disturbed, from 
being carried inbye by the air-current. Further, by removing the 
dust by brushing, the heavier portions, which are not dangerous, 
are removed, and the lighter and inflammable particles, which 
are too light to fall to the ground, are left. Consequently, in 
order to effectively deal with the dust, it should be brushed and 
cleared away at the same time as a water-spraying tub is work- 
ing backward and forward on the inbye side ; and also further 
assisted by fixed sprays at different parts of the roadway, fed by 
water from the rising main of the pumps. These appliances 
should produce a spray of such fineness that it would saturate 
the atmosphere, the moisture being carried by this means into 
every corner and also to the face of the workings. This 
water-spraying should be worked during all hours of the day, 
and it would also moisten dust carried in by the intake-air from 
the screens as well as that made from the full tubs. 

The following lessons may be learnt from this explosion : — 
(1) The removal of coal-dust from the roadways, assisted by 
tub-sprays and sprays under pressure from the rising main of 
the pumps. (2) The thorough examination, by questions, of all 
shot-lighters as to their duties and the rules to be enforced, when 
giving out licenses. (3) The instilling of the fact into shot- 
lighters that, even with a permitted explosive, no shot should be 
fired where gas is present ; and that, when using such an explo- 
sive in an unstemmed shot-hole, or where it has little work to 
do, it is possible to ignite coal-dust without the presence of 
gas. (4) Under no consideration must any charge of explosive 
be fired, except in a properly drilled hole, efliciently stemmed 
with clay. And (5) the absolute prohibition of blasting on main 
haulage-roads without a written authority from the manager. 



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188 DISCUSSION — ^EXPLOSION AT WINGATE GEANGE CX>LLI£&Y. 

Mr. C. C. Leach (Segliill) wrote that Mr. Buegg stated that 
all main roads should, as far as practicable, be kept free from 
coal-dust. He (Mr. Leach) thought that the act of brushing the 
roadways with hand-brushes would raise a cloud of impalpable 
dust, and therefore of the most inflammable character, which 
would settle on the sides and roofs. This fine dust would be a 
greater source of danger than dust containing gritty and larger 
particles of coal and shale, which would tend to prevent the igni- 
tion of the dust ; the gritty and larger particles forming the inert 
portion of it. It might, indeed, be desirable to introduce shale- 
dust to neutralize the coal-dust. In very hot pits, extensive 
watering would make it almost impossible to work in the steamy 
atmosphere, which would prove injurious to the health of the 
workmen. 

Mr. J. P. KiRKUP said that Mr. R. L. Galloway* appeared to 
question the verdict or decision of H.M. inspectors of mines and 
Mr. Buegg as to the cause and origin of the Wingate explosion. 
He thought that mining engineers in the county of Durham, how- 
ever, were generally in agreement with the report of H.M. 
inspectors of mines ; and, had those gentlemen been present, he 
would have liked them to have refuted, what he might call pre- 
sumptuous assertions founded, not on personal observation and 
knowledge, but entirely on a superficial consideration of the 
evidence given by the witnesses. 

Mr. W. C. Blackett said that he was not surprised that 
explosions occurred, arising, like that at Wingate Grange colliery, 
out of the use of high explosives, when for so many years there 
had been no serious explosions from gunpowder. It was a fact 
that men would use high explosives under conditions where they 
would never have dreamt of using gunpowder, and that was the 
case at Wingate Grange colliery. It was futile for Mr. B. L. 
Galloway, or anyone else, to controvert the observations that were 
made at Wingate Grange coUieiy, as it was absolutely certain 
that the conclusions of H.M. inspectors of mines as to the cause 
of the explosion were correct. There could be no doubt that the 
explosion was caused by the particular shot fired under the cir- 
cumstances described in the report. The man who fired the shot 
would never have dreamt of doing what he did if he had been 

• " The Wingate Grange Explosion," by Mr. R. L. Galloway, The Colliery 
rol, : 



Ouardiaiiy 19079 vol, zciii., page 635. 



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DISCUSSION — ^EXPLOSION AT WINGATE GEANGE COLLIEEY. 189 

required to use gunpowder; and therefore they had a curious 
anomaly^ that in this case gunpowder would have been the safer. 
No man would place a charge of gunpowder on the top of a 
projecting stone, and cover it with grease and dust. The man 
knew that an explosive, like geloxite, containing nitro- 
glycerine, would break down a piece of stone, and, having nothing 
else particular to do, he put his time in that way. There could 
be no doubt about the origin of the explosion. 

After reading the reports on the Wingate Grange explosion, 
the uppermost thought in his (Mr. Blackett's) mind was the 
length of time wasted at the enquiry before the coroner, some of 
which was due to the necessity of imparting technical instruction 
to persons who took prominent parts therein and who were 
ignorant of even the elements of mining. The report of Mr. 
R^egg, considering his lack of familiarity with mining, was 
most able ; and there wetre few men who, under similar circum- 
stances, could have written so clearly on the subject. What 
he might say, therefore, was not in disrespect to that gentleman, 
but was meant to find fault with a system which permitted a 
person, more or less completely ignorant of mining, to report in 
authoritative terms, and to pass opinions upon so highly technical 
a subject. The reports were, he supposed, intended to be records 
for future guidance, and as such should only be written by men 
who knew the subject completely ; otherwise they would tend to 
mislead (as he thought that this one might do, and as others pos- 
sibly had done), notably that written by Mr. J. E. Joel on the 
Brancepeth explosion.* He (Mr. Blackett) would therefore warn 
students against the conclusions drawn by gentlemen who came 
down as oflSicial reporters to the Home Secretaay, and he advised 
them to stick to the facta related so clearly and ably by the men 
who knew, namely, H.M. inspectors of mines. In this case, an 
eminent lawyer, who might never have been inside a mine in his 
life, ventured to make a report on the cause of an explosion in 
a mine aud on the means which, in his opinion, should be adopted 
to guard against like occurrences. He (Mr. Blackett) valued the 
opinion of a lawyer on law, but on mining he regarded it as 
merely interesting. 

* Reports to the Right HonourMe the Secretary of State for the Home Depart- 
ment on the Circumstances attending an Explosuyii which occurred cU the Brancepeth 
Colliery in the County of Durham, on the 13th of April , 1896, by Mr. J. Edmondson 
Joel, Barrister-at-law, and by Mr. R. Donald Bain, H.M. Inspector of Mines, 
1896 [C..8174], pages 3 to 14. 



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190 DISCUSSION — ^EXPLOSION AT WINGATE GRANGE COLLIERY. 

It waa instructive to hear from Mr. Ruegg's report that he was 
of opinion that the ventilation was suflScient, that part of the 
haulage-road was dusty and that the dust was dry, but this would 
perhaps be more correctly described as the balance of opinion of 
those who knew. It was also interesting to observe how reluct- 
antly Mr. Euegg accepted what he called the "theory/* put for- 
ward by the officials of the mine with the help of expert assist- 
ance ; but it was more than theory, it was a definite fact 
ascertained by those who knew, and scepticism was not warranted. 

He (Mr. Blackett) chiefly objected to Mr. Ruegg's opinion 
that the system adopted by Mr. C. S. Games, at his collieries, of 
brushing down the dust with hand-brushes, if it were adopted 
generally, would greatly minimize the risk of explosion by coal- 
dust. Personally, he considered that brushing down dust was 
not only quite impracticable, but was more or less futile, and 
perhaps even somewhat dangerous. No doubt large quantities 
of small particles of matter might be removed in this way ; but he 
maintained that it would be impossible to brush off from timber 
and other ledges so much dust as would leave a quantity so small 
as to be harmless, and it was dangerous to give an impression 
that such brushing could be effectual. Moreover, the most 
dangerous dust would be moved on by this means nearer and 
nearer to the face, carried by the air-current to a part of the 
mine where it would be even more oKjectionable than before. 

If managers would only make up their minds to use water, 
and with a fine impalable spray wash the dust from the timber 
and ledges, the dust would then be effectually removed or rendered 
harmless for a considerable period. Water could reach places, 
untouched by the brush, and could be used in quantities which 
would have but a superficial effect, without the necessity of swill- 
ing. It was quite true that some stones would not stand water, 
but there were few that would not bear a superficial quantity. 
He thought that this danger (although freely admitting that it 
existed) had been made far too much of, and he was afraid that 
the exaggeration, in the end, would do more harm than good. 

Mr. T. E. FoRSTER said that he did not quite see himself 
why a lawyer should make a report on collieries; but, if the 
members read Mr. Ruegg's report, they would find that the 
opinions which he expressed were really those of H.M. inspectors 
of mines. He (Mr. Forster) could not understand why they were 



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DISCUSSION — EXPLOSION AT WINGATE GRANGE COLLIERY. 191 

not allowed to report alone. In this instance, Mr. Ruegg seemed 
to have accepted their opinions and put them forward as his own ; 
but, on another occasion, the gentleman instructed by the Home 
Secretary might differ with E.M. inspectors of mines, and he 
might make recommendations at variance with theirs and with 
the general practice. The Royal Commission on Accidents in 
Mines, now sitting, had paid great attention to the dust-problem. 
The evidence was published week by week as the sittings pro- 
ceeded, and was scarcely necessary to call the special attention 
of mining engineers to the difiSculties and dangers in connection 
with coal-dust, for they had all been aware of them for many 
years. The publication of the evidence, however, would be very 
helpful, in so far as it would draw the attention of under-officials 
and shot-firers to the matter ; for one knew from personal experi- 
ence that these men did not read professional papers, and were 
not fully aware of the necessity of counteracting these dangers. 
He approved of the suggestion that they should be cross-examined 
by colliery managers from time to time. When Special Rules 
were established, and for some time afterwards, everybody ob- 
served them ; but after a few years they were apt to be forgotten, 
and it was desirable that everyone's ideas should be furbished up 
occasionally. He thought that it would prove advantageous if 
copies of the reports upon the Wingate Grange explosion were 
distributed to managers and under-managers for careful 
consideration. 

Mr. S. Hare, while he agreed with Mr. Blackett in almost 
every way in connection with the use of water, said that water- 
ing could not be adopted under all conditions, and then the only 
thing that could be done was to adopt brushing. For instance, 
watering was extensively adopted at the Murton collieries, and 
several miles of water-pipes, from 1 inch to IJ inches in diameter, 
had been laid, with hydrants fitted at distances varying from 150 
to 250 feet apart. He was a believer in the use of water-sprays 
and occasionally used them. Any system of watering was, how- 
ever, in his opinion of little value unless the dust was gathered 
together and sent out of the pit at short intervals. Brushes 
were used to a limited extent at the Murton collieries, but only 
where it was considered unsafe to apply a large quantity of water. 
He had adopted a system, in connection with the shot-firers, 
which was, he thought, worthy of emulation. In each district. 



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192 DISCUSSION — EXPLOSION AT WINGATE GRANGE COLLIEEY. 

where shot-firing was allowed, printed instructions were posted 
for the guidance of the shot-firers and to ensure that their work 
should be carried out with the utmost safety. He thought that 
the posting of these instructions, which were of a stringent char- 
acter, brought the subject very closely under their notice. la 
addition, the more important regulations were printed on the 
back of the license given to each shot-firer, and this helped to 
impress upon each shot-firer the necessity and the importance of 
the regulations that he was required to observe. 

Mr. C. A. Crofton (Morpeth) said that the masterly report of 
H.M. inspectors of mines had convinced him that the Wingate 
Grange disaster was purely and simply a coal-dust explosion. He 
agreed with Mr. W. C. Blackett and Mr. S. Hare with regard to 
the watering of haulage-roads, which, although suitable in one 
pit, might not be so advantageous in another, on account of the 
nature of the strata and the depth of the pit. Cool varied 
considerably in its properties, moisture, etc., and tests might 
prove that all coal-dust would not explode, some being more 
highly sensitive to ignition than others. Consequently he 
suggested that coal-dusts from Wingate Grange and from some 
shallower pits might be tested. In the transportation of coal 
the larger pieces worked to the bottom of the tub and the dust 
to the top, and on meeting the intake-air the dust was blown 
out of the tub and deposited on the sides, timbers, roof, etc. He 
suggested, as a remedy, that all tubs should be fitted with a 
lid or cover, which would be removed from an empty tub and 
put by the landing-lad on a full tub, and then again would be 
taken off by the shaft-lad and placed in an empty tub. Catches 
would be fitted on the tubs to prevent the lids from being blown 
off the tubs. He thought that this method might prevent the 
formation of 80 per cent, of the dust at present being deposited. 

Mr. James Ashworth (Old Colwyn) wrote that it would 
interest him, and doubtless many other engineers, to have addi- 
tional information as to the part played by steam. It was stated 
that the steam-pipes were broken; that the steam from three 
ranges of pipes was added to the after-damp ; and that one sur- 
vivor, J. McDougall, who escaped alive, was scalded by steam 
in the Main coal-seam, whilst his mate, J. G. Dixon, was killed 
by force : was this force from the steam or from the explosion ? 
It might be concluded, after reading the reports, that the flame 



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DISCUSSION — EXPLOSION AT WINGATE GRANGE COLLIEEY. 198 

of the explosion weat down the stable way and burned G. Bloom- 
field, but not the horse found dead near to him. He (Mr. Ash- 
worth) would, therefore, like to know whether the appearance 
of Bloomfield might not be due to scalding, and not to burning ; 
more particularly because the horse was not singed, neither were 
any of the horses singed in the stable. But it was quite conceiv- 
able that steam and after-damp were either jointly or severally . 
the cause of their deaths. At Elemore colliery, an explosion, 
originating in a similar way, was carried down the shafts to the 
mines below ; and therefore, if the dust from the screens made the 
Low Main haulage-ways dangerous, the shafts themselves must 
have been still more dangerous, as a consequence of the larger 
volume of air passing down to the lower mines. In his (Mr. 
Ashworth's) opinion, the steam saved the lower mines ; as no form 
of water, excepting steam, could saturate an air-current suflS- 
ciently to place a barrier in front of a gas or dust explosion. 
Roughly estimated, air would have to contain over 5 per cent, of 
water-vapour, or, say, 26 grains per cubic foot, before it could 
exercise any controlling influence.* Not only did the steam, in 
this way, serve a most useful purpose as a life-saving agent, but 
it also appeared to have brought the explosion to a conclusion, 
before it extended into the second east way, by its effect on the 
ventilation. Thus, the large volume of steam struggling to escape 
in every direction, particularly downwards, and acting in like 
manner as the steam- jet of an injector, might for the time have 
reversed the ventilation in the Low Main coal-seam : that was to 
say, both the intake- and return-airways were brought under 
an influence tending to draw back the intake-air, and to force the 
return-air down the Harvey staple. The next phase would be 
during the period of condensation, when air struggling to enter 
from every direction to fill the void, tended to draw back the 
advancing flame, supposing that the effect of the steam in the shaft 
had not already caused the arrestment of the advancing flame by 
the large volume of dust disturbed. It was a most marked feature 
in this explosion that the explorers experienced very little trouble 
from after-damp ; and that the men escaping from the second east 
district also met very little after-damp, or they could not have 
travelled such long distances before succumbing. He (Mr. 
Ashworth) regretted that the plans attached to the Reports did not 

* <*The Rate of Explosions in Gases,*' by Prof. H. B. Dixon, Trans, Inst. 
M. B., 1892, vol. iii., page 317. 



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194 DISCUSSION — EXPLOSION AT WIXGATE GRANGE COLLIERY. 

indicate the doors, stoppings, and air-crossings that had been 
blown out, and consequently where, in addition to the blown-out 
casing in the upcast-shaft, the air short-circuited after the explo- 
sion. For the foregoing reasons, he (Mr. Ash worth) had concluded 
that excess of dust had brought the flame to an end, and not want 
of (}ust, particularly as the greatest heat-effects were demonstrated 
close to the point where the explosion appears to have terminated ; 
and moreover some at least of the great force exhibited between 
the shafts and the stable way, must have been due to the escaping 
steam. He was also of opinion that, had it been possible for the 
first band of explorers to descend to the Low Main seam sooner 
than they did, and check the escape of air into the upcast-shaft, 
most of the men in the north-east way would have escaped alive. 

The hygrometrical observations* were interesting, as they 
showed that the intake-air at the shafts was saturated with water ; 
and, although there was a difference of 1*2 grains between the 
observations made on October 22nd and those made on November 
9th, 1906, yet when the air reached the curve of the second east 
way, the water-content had risen to 0*2 grains per cubic foot, being 
on the first date 04 grain, and on the latter date 0*2 grain only, 
below absolute saturation. Therefore, it was doubtful whether it 
was correct to call either the dust or the atmosphere ** drj'." At 
the place where Bloomfield was found, the air was saturated, 
and carried 6*3 grains of water per cubic foot of air. It waa 
perfectly clear that air saturated with moisture was no protec- 
tion against the extension of an explosion. On the other hand, it 
assisted in the oxidation process ; and, moreover, in addition, the 
explosion was reported to have passed over two wet places, of 
considerable length, although neither of these were indicated on 
the plans accompanying the Reports. With these facts so plainly 
demonstrated, it was a misnomer to describe the paii; of the mine 
traversed by the explosion as ** dry." 

The analyses of dust were another interesting feature of the 
Reports, but they did not throw any distinct light on the question, 
as to whether dust containing a certain proportion of ash was 
explosive or not.t For instance, the dust near Maddison's shot 

• Reports to His Majaty^s Stcretary of State for the Home Department on 
the Circumstances attending an ICxplwion which occurred at Wingate Grange 
Colliery, Wingate, on the 14th October, 10O6, by Mr. A. H. Raegg, K.O., and 
Messrs. R. D. Bain and J. B. Atkinson, M.8c., two of U.M. Inspectors of Mines, 
1907 [Cd. 3379], page 30. 

t Ibid,, page 35. 



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DISCUSSION — EXPLOSION AT WINGATE GEANGE COLLIERY. 195 

contained 44'13 per cent, of ash ; and at the point near the end 
of the explosion on the stable way, 34*80, 39*20 and 44*14 per 
cent,, and in the north district, near the end of the explosion, 
only 26*95 per cent. These values, when compared with those 
obtained at Camerton, Courrieres and other collieries, did not 
demonstrate that such percentages of ash were a safe factor. The 
addition of an analysis of the coal of the different seams would 
have been useful for purposes of comparison. 

Possibly no disaster would have resulted from the shot, if 
Maddison had not used greasy dust from the roadway to cover 
the charge, and it was in aJl probability the great flame from this, 
as at Timsbury colliery, that really originated the disaster. 

Mr. A. M. Hedley (Blaydon Bum) wrote that, during the 
discussion on the Reports dealing with the Wingate Grange col- 
liery explosion, Mr. C. C. Leach raised objection to brushing the 
main roadways as it ** would raise a cloud of impalpable dust, and 
therefore of the most inflammable character, which would settle 
on the sides and roofs."* Views differed considerably as to the 
necessity for, or practicability of, keeping all main roads entirely 
clear of dust throughout their full length; but, in his (Mr. 
Hedley's) opinion, every dry and dusty colliery should have its 
roadways dealt with as far as possible in this direction, and he 
thought that the idea was sound of having, at any rate, certain 
lengths of the road kept at intervals clear of dust. Surely few 
engineers would contend that there was no necessity for removing 
the dust which accumulated in the main roadways, and to his 
mind the only point in doubt appeared to be the means to be 
adopted for its removal. Mr. W. C. Blackett was of opinion that 
" brushing down " was '* impracticable " . . . . " and perhaps 
even somewhat dangerous. "t Mr. Blackett favoured, however, the 
system of watering, for the purpose of washing off the light dust 
which had accumulated on the roof and sides; and a similar 
expression of opinion from Mr. Hare, with the latter's extensive 
experience at Murton, should carry considerable weight. 

An effective combination, if feasible, of brushing and water- 
ing seemed desirable, and he (Mr. Hedley) wished to recommend 
a means of accomplishing this object which had recently been 
suggested to him by Mr. R. Crombie, an associate of the 
Institute. It was an idea which the latter had previously carried 

* Trans, Iwtt, M.E.^ 1907,'vol. xxxiii., page 1S8. f i^d,^ page 190. 



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196 DisctrssioN — explosion at wingate gbange colueet. 

out, and he (Mr. Hedley) had since tried it with satisfactory re- 
sults. He would assume that a length of 300 feet was required to 
be cleared of dust on a main haulage-road, which at the same time 
served as an intake-airway. On the inbye side (or the outbye side, 
if a return-airway) of this area to be treated, a piece of brattice- 
cloth, thoroughly soaked in water, was attached along its upper 
edge to the roof-timber, across the full width of the road. 
It was hung at such a distance from the roof as was deemed 
necessary, without offering too great an obstruction to the ven- 
tilating current; aoid, in the case of a strong current of air, 
the canvas should be weighted by attaching pieces of timber 
to its lower edge. When the brattice-cloth was fixed, the dust- 
zone was treated by water-sprays to such an extent as the nature 
of the seam's roof or thill would allow, and it was then found 
that the operation of brushing the dust from the roof and sides 
could be carried out with impunity. The light dust raised, if 
carried forward by the air-current, would, on meeting the wet 
canvas-obstruction, be moistened and fall in layers on to the 
floor, whence, with the bottom dirt, it could be removed and 
filled into a tub when the operation was completed. Possibly 
a succession of wet sheets might even give better results, and 
wet canvas stretched along the roof and sides would further 
improve matters. It was possible that one sheet, treated with 
a continuous spray of water throughout the brushing operation, 
would answer the required purpose. It appeared to him (Mr. 
Hedley) that the efiicacy of this treatment in the final capture 
of the fine dust depended on the fact that the dust was driven 
against a wet surface, instead of the water being thrown on to the 
dust and so acting as an agitating and disturbing agent. 

The President (Mr. J. H. Merivale) said that the chief point 
brought out by the reports on the Wingate Grange explosion was 
the danger from coal-dust. It seemed a truism that there was 
danger connected with coal-dust, but on reading the Reports it 
appeared that many persons still are, or at any rate were, in 
doubt as to the dangers connected with it. He agreed with Mr. 
W. C. Blackett to some extent as to the undesirability of bring- 
ing down gentlemen ignorant of mining matters to report on 
colliery explosions. Perhaps the classical instance was that of 
Haswell colliery in 1844, when Sir Charles Lyell and Prof. 



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DISCUSSION — SINKING BY THE FBEEZING-FSOCESS. 197 

Michael Faraday, two of tke most eminent men of the day, 
advised mining engineers to put in pipes to drain gases from the 
goaves. If, however, an able man, who had no prejudices and 
knew nothing about mining, presided at an enquiry and heard 
all that was said on both sides, he was in a good position to form 
an opinion. 



DISCUSSION OF MR. E. SEYMOUR WOOD'S PAPER ON 
"SINKING THROUGH MAGNESIAN LIMESTONE 
AND YELLOW SAND BY THE FREEZING-PROCESS 
AT DAWDON COLLIERY, NEAR SEAHAM HARBOUR, 
COUNTT DURHAM."* 

Mr. James H.. Brace (New York) wrote that, while this work 
was entirely successful, it appeared (1) to emphasize the necessity 
of keeping the borings plumb and at a uniform distance ; and that 
(2) it was very difficult to form an ice-wall while water was run- 
ning through the material to be frozen, and that every precaution 
should be taken to stop any such flow before starting freezing. 
He understood that the contractors for the work described had 
had wide experience of iJiis kind of work, and he would like to 
enquire what experiments had been maide with lower tempera- 
tures. With the machinery now in use, it was practicable to 
reduce the temperature of the brine down to — 30^ Fahr,, and it 
would seem to be advantageous to make it as low as practicable. 
In conclusion, there had, so far as he knew, been only two 
applications of the freezing process for excavation in America in 
recent years. One of these was on the rapid-transit tunnel be- 
tween New York and Brookljm. This had recently been fully 
described in the technical press ; t and the other work had not as 
yet reached a final stage. 



Mr. M. Malplat's paper on " Sliding-trough Conveyors " was 
read as follows : — 



* Trans. InsL M. S,, 1906, vol. xxxii., page 651. 

t " The Freezing Prooess in the Battery Tunnel, New York," The Engineer- 
ing Record [New York], 1906, vol. liv., page 656. 



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198 SLIDING-TROUGH CONVEYORS. 



SLIDING-TROUGH CONVEYORS.* 



By M. MALPLAT. 



At the present time, in No. 7 pit of the Lens collieries, the 
Saint-Augustin seam is being worked, with the following 
characteristics: — The seam is formed of one single bed of coal, 
varying from 20 to 24 inches (0*5 to OG metre) thick in the more 
regular poi*tions. The coal is hard, but it generally cleaves 
into big blocks, without bedding. The roof is bad, and the 
floor variable. The average dip is 11 degrees. 

The method originally adopted for working this seam was 
by means of rising gateways, 52 feet (16 metres) wide, with a 
road in the middle of each. The working-cost of this system 
was somewhat high, as the essential elements, namely, the 
hewing of the coal and the opening of the roads, were expensive. 
The stone taken up in the roads must be thick, because the seam 
is thin ; and, in addition, each foot of roadway corresponds only 
to a small output of coal. In order to reduce the costs of stone- 
work, the management were induced to suppress every alternate 
road, giving each working-face a length of 100 feet (30 metres). 
It then became indispensable to establish, on either side of the 
face, which measured 50 feet (15 metres), some method of con- 
veying the coals. 

The following system was adopted: — The coal-face, at each 
side of the rising gateway, is made at a small angle with the 
strike of the seam, and with a slight slope towards the road; 
and, in the space between the coal-face and the goaf, rails weigh- 
ing 10 pounds per yard (5 kilogrammes per metre) have been 
laid (Fig. 1). The gauge of the rails is 9^ inches (24 centi- 
metres); they are connected by riveted sleepers, and form 
lengths of 8J feet (2^ metres), fitted to the neighbouring lengths 
by means of fish-plates. Along this road slides a trough made 

* "L'Emploi . . . . de Couloirs glissants pour le Boutage dans les Tallies," 
by Mr. M. Malplat, Comptes rendua mejisuds de9 R6\ini<yiis de la Soci6t6 de 
V Industrie Min^rait, 1907, pages 27-2$.— Translated by Prof. Henry Louis, M,A. 



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SLIDIXG-TROUGH CONVEYOES. 



199 



•of sheet-iron, 0*12 inch (3 millimetres) thick, in the form of a 
semi-cylinder, 20 inches (50 centimetres) in diameter and 6J 
feet (2 metres) long. This trough is protected by three rings of 
half-round iron, which rest upon the rails (Fig. 2). A rope, 50 
feet (15 metres) long is attached to each end of the trough, and 
allows it to be drawn alternately from the further end of either 
side of the face to the road. 

The working is organized as follows : — Five workmen, one of 
whom is an assistant, are engaged at the face. The assistant 
works in the roadway, drags the troughs when they are full, 
and loads the coals into the tubs. The amount of pull required 
to move the trough is very small, and it is about the same in 
either direction, full or empty, on account of the gentle slope of 
the road. Unloading the trough is particularly easy, when, as 
is the present case, the cut for the roadway is made in the 




Fig. L— Plan of Gateway. 
Scale, 48 Feet to 1 Inch. 



Fig. 2.— Section of Conveyor. 
Scale, 12 Inches to 1 Inch. 



l)ottom-stone. The trough is tipped into the tub standing in 
iihe roadway by attaching the rear cord of the trough to a prop 
at the far end of the face ; and, by suitably regulating the length 
of this cord, the trough can be abruptly stopped, producing 
automatic discharge of the contents. In this method of dis- 
charge, the trough is open at either end; but often, on the con- 
trary, in order to increase its capacity, the lower end is closed 
by a movable door. The trough has a capacity of about 3^ 
■cubic feet (2 hectolitres); in practice, three troughs fill a tub 
•carrying lOJ cwts. (545 kilogrammes) ; and two troughs are suffi- 
cient when the seam is thicker, and the trough can be loaded 
above the level of its edges. Tery little height is required, 
as the trough will pass under a height of 14 inches (0*35 metre). 

The system has been well received by the workmen, who 
found formerly that the transport of the coal was laborious on 



vol. XXXni.-1906.19OT. 



16 



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200 DIvSCXTSSIOX — SLIDIXG-TROUGH COXVEYORS. 

account of the thinness of the seam. The coal is loaded, as 
fast as it is broken down, into the trough, and the face always 
remains free for the ventilating current and the passage of the 
miners. The width of the working-face of each gateway has 
been doubled without increase of the hewing prices, and no 
payment is made for laying the road for the conveyor. These 
troughs are also used for throwing back into the goaf the 
debris made in cutting the roads, part of which was formerly 
sent to bank in tubs. 



Mr. T. C. FuTERS said that the trough, merely lying on the 
rails and having a capacity of 3^ cwts., would require a strong 
boy to move it. 

Mr. Hexry Lawrence said that the appliance seemed a very 
unusual one : its adoption might have been necessary under the 
circumstances in which it was employed, but he thought that 
friction would soon wear out the trough. 

Mr. T. E. FoRSTER asked what strain or pull was required to 
move the empty and the loaded trough, whether the system had 
been in use any length of time, and the cost of this method of 
conveying. 

Mr. C. A. Crofton remarked that tubs carrying lOJ cwts. 
were rather large for a seajoi less than 2 feet high. The stone- 
work would consequently be very costly. 

The President (Mr. J. H. Merivale) said that the method had 
evidently been developed, in order to reduce the cost of workings 
thin seams by decreasing the number of gateways. Attempts 
had been made, some with considerable success, and others with 
not so much ; and one could hardly tell from a cursory glance 
whether this proposal was likely to prove successful. 



Mr. M. Walton Brown read the following ** Memoir of the 
late John Daglish." 



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Vol XXXI I L, Plate VII, 




JOHN DAGLISH, 

PRESIDENT OF THE NORTH OF ENGLAND INSTITUTE OF MINING AND MECHANICAL ENGINEERS, 1884-1888. 



Born on June idth, 1828^ and died on August ^th, 1906. 
(Presented by The North of England Institute of Mining and Mechanical Engineers.) 



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MEMOIR OF THE LATE JOHN DAGLISH. 201 



MEMOIR OF THE LATE JOHN DAGLISH. 



By M. WALTON BEOWN.» 



The late Mr. John Daglish, mining and civil engineer, of 
Rothley Crag, Cambo, Northumberland, was bom in Newcastle- 
upon-Tyne, on June 26th, 1828. He attended Dr. John 
CoUingwood Bruce's school in Newcastle-upon-Tyne from 1836 
to 1838. Afterwards he went to Wesley College, SheflSeld, where 
he remained until 1843; and during that year he commenced 
his apprenticeship as a mining engineer with Mr. Nicholas 
Wood, at Killingworth collieries. In 1848, he went to TJrpeth 
colliery, as assistant viewer to Mr. Edward Fenwick Boyd ; and 
from October 1849 to 1850, he attended lectures at King's and 
University Colleges, London. 

In 1850, he went to Barrington colliery,* as viewer, under 
Mr. James Longridge ; and, in 1852, he was appointed viewer 
of BadclifEe colliery. In October, 1854, he was appointed 
viewer of Seaton colliery, then the property of the Earl of Dur- 
ham and the Owners of Hetton collieries. 

In 1855, he married Miss Sarah Ellen Eobson of Paradise, 
near Newcastle-upon-Tyne, and of the marriage there was one 
daughter, Adelaide Mary, who was bom at Seaton House on 
December 28th, 1856, and died at Rothley Crag in 1905. 

Mr. Daglish became viewer of the Hetton collieries in 1859. 
He was in 1863 appointed chief viewer to the collieries belonging 
to the Marchioness of Londonderry ; in 1865, he became general 
manager ; and he resigned this position in 1869. 

He became managing director of the Whitburn colliery in 
1873 ; and in the same year, he was appointed managing director 
of Cwmaman colliery, in South Wales, and held the appointment 
until his resignation in 1895. He was also agent for Kimbles- 
worth colliery, Durham ; Silksworth colliery, Durham ; Hough- 
ton Main colliery, Yorkshire ; Swaithe Main colliery, Yorkshire ; 

* Extended and revised from the Nexccasth Daily Journal ^ August 16th, 1906, 
page 5. 



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i^02 MEMOIR OF THE LATE JOHN DAGLISH. 

aad^Manvers Main colliery, Yorkshire. He was a director of 
Llest colliery, South Wales ; and as check viewer held numerous 
mining agencies. 

In July, 1891, Mr. Daglish resigned all colliery manage- 
ment, and purchased the Rothley Crag estate of 1,100 acres. 
The building of the hall at Bothley Crag was completed in 
1895, and here he chiefly resided until his death. 

He was one of the 44 " colliery owners, viewers and others 
interested in the coal trade," who met in Newcastle-upon-Tyne, 
•on July 3rd, 1852, and founded The North of England Institute 
of Mining and Mechanical Engineers, '* to meet at fixed periods 
and discuss the means for the ventilation of coal-mines, for the pre- 
vention of accidents, and for general purposes connected with the 
winning and working of collieries." He retained his member- 
ship up to his death, and at all times took a keen interest in the 
furtherance of the objects of the Institute. He was for many 
years a member of council, and a Tice-president, and occupied the 
office of President during the years 1884 to 1886. Mr. Daglish, 
in addition to taking part in the business of the meetings, wrote 
^he following papers: — 

"The Relative Heating and Economic Values of Bound and Small 

Coals," TraM. X. E, Imt., 1856, vol. iv., page 283. 
"Experiments on the Strength of Wire-ropes and Chains," ibid,, 1859, 

vol. vii., page 211. 
"The Injurious Action on Iron in Tpcast Shafts," ibid., 1860, vol. viii., 

page 179. 
"The Cause of the Loss of Strength in Iron Wire when Heated," 

ibid., 1860, vol. viii., page 181. 
"The Construction of Ventilating Furnaces," ibid., 1861, vol. ix., 

page 131. 
""The Various Modes of Ascertaining the Velocities of Currents of 

Air in Mines, in order to Determine the Quantities Circulating in 

a given Time," in conjunction with Mr. John Job Atkinson, ibid., 

1861, vol. X., page 207. 
""The Destructive Action of Furnace Gases in Upcast Shafts," ibid., 

1861, vol. xi., page 19. 
^'The Donesthorpe, Firth and Ridley Coal-cutting Machine," in con- 
junction with Mr. Lindsay Wood, ibid., 1863, vol. xii., page 63. 
*'The Ventilation of Underground Boilers," in conjunction with Mr. 

William Armstrong, ibid., 1863, vol. xii., page 79. 
"Paradoxes in the Ventilation of Mines," in conjunction with Mr. John 

Job Atkinson, ibid., 1863, vol. xii., page 93. 
*'The Magnesian Limestone of Durham," in conjunction with Mr. 

George Baker Foster, ibid., 1864, vol. xiii., page 205. 
''Minerals and Salts found in Coal Pits," in conjunction with Mr. 

R. Calvert Clapham, ibid., 1864, vol. xiii., page 219. 



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MEMOIR OF THE LATE JOHN DAGLISH. 20$ 

<* Certain Improvemento in the Construction of the Water-gauge," Trans, 

X, E. Iiist,, 1865, vol. XV., page 103. 
"The Broadbent Patent Safety-cage," ibid., 1866, vol. xvi., page 33. 
"The Conveyance of Coal Underground," ibid., 1867, vol. xvi., page 53. 
"A New Application of the Water-gauge for ascertaining the Pressure 

of the Ventilating Column in Mines," ibid,, 1867, vol. xvii., 

page 27. 
"The Counter-balancing of Winding-engines," ibid., 1871, vol. xx.,. 

page 205. 
"Some Remarks on the Beds of Ironstone occurring in Lincolnshire," 

in conjunction with Mr. R. Howse, ibid,, 1874, vol. xxiv., page 23.. 
"The Application of Counter-balancing and Expansion to Winding- 
engines," ibid., 1876, vol. xxv., page 201. 
"An Improved Expansion Gearing for Winding-engines," ibid., 1879,. 

vol. xxix., page 3. 
"Account of a Discharge of Lightning at Kimblesworth Colliery, on 

July 12th, 1880," ibid., 1881, vol. xxx., page 129. 
"Presidential Address," ibid., 1886, vol. xxxv., page 223. 

With a view of celebrating the fiftieth year of the reign of H.M 
Queen Yietoria, the council of The Xorth of England Institute of 
Mining and Mechanical Engineers decided to hold a mining exhi- 
bition in 1887. As soon as the details of the scheme were published, 
it was taken up by the Mayor and many of the members of the 
Council of the city of Xewcastle-upon-Tyne ; and, at a public 
meeting, it was determined to expand the project and make it 
worthy of the metropolis of the North of England. Committees- 
were appointed to carry out this extended scheme, and Mr. John 
Daglish was appointed chairman of the Executive Council. The 
Newcastle-upon-Tyne Royal Mining, Engineering and Indus- 
trial Exhibition, in which he took a keen interest, proved success- 
ful in every respect. 

Mr. Daglish took a leading part in the inception and forma- 
tion of The Institution of Mining Eligineers. In his " Presiden- 
tial Address "* to the members of The North of England Insti- 
tute of Mining and Mechanical Engineers, on August 7th, 1886,. 
he referred to the several schemes which had been mooted for 
the concentration of the various mining institutes. He con- 
sidered that any attempt to amalgamate these institutes into one 
body would be difficult, if not impossible, but thought that a 
federation confined chiefly to the publication of their Transactions 
could be carried out to their general advantage. It would place 
the papers read at each institute in the hands of all mining 
engineers, and prevent repetition of papers, and duplication of 

• TVoiM. X. E. Inst., 1886, vol. xxxv., page 243. 



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204 MEMOIR OF THE LATE JOHN DA6LISH. 

investigations and experiments by committees on special subjects 
of general interest. An institute representing the whole of the 
mining science of Great Britain would be able to supply reliable 
information to the Government upon the real practical require- 
ments of legislation, and would be a power to resist any proposed 
legislation contrary to the real interests of mine-owners and 
workmen. Mr. Daglish lived to see the successful realization of 
his ideafi, and was a member of council and a Vice-president 
of The Institution of Mining Engineers until his death. 

Mr. Daglish, for' many years, was a governor of Armstrong 
College, Newcastle-upon-Tyne, and in 1890 he was appointed 
to the council, of which he remained an esteemed member until 
his death. He devoted considerable attention to its manage- 
ment during the later years of his life, and his name will always 
remain associated with Armstrong College owing to his munifi- 
cent devise of property for its endowment. He founded the 
Daglish travelling fellowship in mining, in connection with 
that college, and the holders, after nomination by The North 
of England Institute of Mining and Mechanical Engineers, will 
be appointed by the special election board of the college. 

He had also been a Fellow of the Geological Society, and a 
member of the Institution of Civil Engineers,* the Institution of 
Mechanical Engineer8,t the Tyneside Naturalists* Field Club, 
the Berwickshire Naturalists' Field Club, the Newcastle Far- 
mers' Club, the Scottish Arboricultural Society, the English 
Arboricultural Society, etc. 

He acted as secretary of the Geological Section of the British 
Association for the Advancement of Science, at their meeting 
held in Newcastle-upon-Tyne in 1863, and as an honorary curator 
and a vice-president of the Natural History Society of North- 
umberland, Durham and Newcastle-upon-Tyne. 

He died in London, on August 9th, 1906, and was interred 
five days later, in Cambo churchyard, Northumberland. 



* '* The Sinking of Two Shafts at Marsden, for the Whitburn Coal Company," 
Minutes of Proceedings of the InslittUion of Civil Engineers, 1882, vol. IxxL, page 
178. 

t *' The Mechanical Firing of Steam Boilers," Proceedings of the Institution qf 
Mechanical Engineers^ 1869, page 155 



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EXPERIMENTAL GALLERY AT ALTOFTS COLLIERIES. 205 



MIDLAND INSTITUTE OF MINING, CIVIL AND 
MECHANICAL ENGINEERS. 



EXCURSION MEETING, 

Held at Messrs. Pope & Peabson's West Riding Collieries, Altofts, 

March 23bd, 1907. 



The members visited the West Riding collieries at the invi- 
tation of Messrs. Pope & Pearson, Limited, and Mr. W. E. 
Garforth, to witness a demonstration of rescue-work in the 
experimental gallery at Altofts collieries. 



EXPERIMENTAL GALLERY AT ALTOFTS COLLIERIES. 

Since the description of the experimental gallery at Altofts 
collieries for testing life-saving apparatus was described in 1901* 
•considerable alterations have been made. A short description 
of the gallery as it now exists may, therefore, be of interest to 
those who may contemplate the erection of a rescue-station. 

The external framework of the gallery is the same as origin- 
ally designed by^ Mr. W. E. Garforth in 1901 ; but the internal 
parts have been altered from time to time, and further obstacles 
added for the purpose of increasing the diflBculties of exploration- 
work and of obtaining additional efficiency from the men wearing 
life-saving apparatus. 

The gallery, as now arranged, is 100 feet long, with a capacity 
of 5,600 cubic feet (fig. 1, plate viii.) ; and it is divided into two 
parts. The first section, AB, 30 feet long, 6 feet wide and 7i feet 
high, is used as a training-ground ; it is termed the " nursery," 
and no obstructions are placed in it. The second section, BCD, 
70 feet long, forms the actual testing-ground, and is made to 
resemble, as far as possible, the damaged roadways of a mine after 
an explosion (fig. 2, plate viii.). The obstacles placed in this 

* " Experimental Gallery for testing Life-saving Apparatus,'' by Mr. W. £. 
Oarforth, Trana, Inat. M. E., 1901, vol. xxu., page 169. 



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206 EXPERIHENTAL GALLERY AT ALTOFTS COLLIERIKS. 

road consist of overturned tubs, rocks and stones, witk broken: 
timber placed irregularly, confined spaces, etc. The general 
arrangement of this section consists of a clear space, D, represent- 
ing the downcast shaft, and from this an upper roadway extends 
to the nursery-section over the debris and other obstacles (fig. 3, 
plate riii.). For the sake of reporting the work done by explorers,, 
the various parts of this roadway have been given distinctive 
names, namely, west road, south road and east road. The longi- 
tudinal section (fig. 4, plate viii.) shows the various obstructions, 
etc. 

At E (fig. 1, plate viii.), a lower roadway, foi-med under tim- 
ber-frames on which the debris rests, communicates, say, from 
Ludgate through Kirkgate, Holgate, Briggate and Mousehole- 
gate to B, where the two roadways emerge into the nursery-sec- 
tion. Four slits, a, 6, c and d (tigs. 1 and 2, plate viii.) connect 
the upper and lower roadways with each other and with the coal- 
faces, represented by Kirkgate and Briggate. The sections 
(figs. 5 and 6, plate viii.) show the relative positions and areas 
of the two roadways. 

The exterior is fitted with seven exit-doors, each h\ feet 
high and 2yV f^t- wide, together with twelve inspection-win- 
dows. The nurser>% AB, has two exit-doors, e and f^ and three in- 
spection-windows, /, m and n ; and the section, BCD, or the actual 
testing ground, five exit-doors, g^ A, /, j and it, and nine inspection- 
windows, 0, py q, r, Sy t, u, V and tr. The windows, varying from 
4 feet by 3 feet to 3 feet by 1^ feet, are so arranged that the attend- 
ant is able to watch the explorer and render assistance if required. 

In the nursery-section, an appliance is placed for ascertain- 
ing the weight that an explorer can lift, when equipped with a life- 
saving apparatus. It consists of a framework and pulley, over 
which is passed a rope attached to a weight of 56 pounds. A 
stretcher weighing 40 pounds, with a dummy-man weighing 
160 pounds, is also used for exercise-purposes. The explorers 
carry a pneumatic horn, similar to that earned by cyclists: it 
is frequently sounded, once to indicate safety and twice for 
danger. 

An arrangement for conveying a man from the mine up the 
shaft to the surface has also been provided. It consists of a 
cradle formed like a saddle, the occupier being placed in a pair 
of trousers, as in the rocket-apparatus ; and it is so arranged that a 



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EXPERIMENTAL GALLEEY AT ALTOFTS COLLIERIES. 207' 

man can be upset without being thrown out of it. If a man 
were put in this appsiratus at a depth of 2,000 feet, it would be 
safe to send him to the surface; and men could descend in it 
wearing the life-saving apparatus. 

An underground pipe connects the two ends, A and D, of 
the gallery ; and, by means of slides, a continuous circulation of 
gases can be maintained, when it is required to make the atmos- 
phere very deleterious ; or fre&h air can be admitted to dilute the 
atmosphere ; or the fumes can be entirely replaced by pure air : 
the whole arrangement being under the complete control of the 
outside attendant (fig. 1, plate viii.). 

When the gallery was constructed, an iron boiler, 30 feet 
long and 7 feet in diameter, was attached for the purpose of 
holding a fire fed with compressed air. This fire represented a 
gob-fire, and afforded a means of testing whether the apparatus^ 
would stand a temperature varying from 140° to 150^ Fahr. 

The results of every trial and any remarks connected with 
the same are recorded by the attendant in a book at the: 
end of each trial. 



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:208 TKAliSACnONS. 



MIDLAND INSTITUTE OF MINING, CIVIL AND 
MECHANICAL ENGINEERS. 



GENERAL MEETING, 
Held at the Institutk Rooms, Sheffield, Afbil 9th, 1907. 

Mr. J. R. R. WILSON, President, in the Chair. 



The minutes of the General Meetings held on February 20th 
land March 9th, 1907, were read and confirmed. 



The following gentlemen, having been duly nominated, were 
•elected : — 

Members — 
Mr. William Jambs Belk, Colliery Manager, Thomclifife Collieries, near 

Sheffield. 
Mr. J. Kenneth Guthrie, Mining Engineer, Crigglestone Collieries, near 

Leeds. 
Mr. Frank H. Waterhouse, Colliery Manager, Denby Grange Collieries, 

near Wakefield. 



The President proposed that the thanks of this Institute 
be given to Messrs. Pope & Pearson, Limited, and to Mr. 
W. E. Qarforth, for their kindness in receiving and entertaining 
the members of this Institute on March 23rd, and giving a demon- 
stration of life-saving apparatus in their experimental gallery. 

The resolution was carried unanimously. 



The Secretary read the " Report on Rescue-work," etc., as 
follows: — 



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REPORT ON RESCUE-WORK. 209 



HEPOET ON EESCTJE-WOEK DONE BY MEN WEARING 
RESCUE-APPAEATUS IN THE EXPERIMENTAL 
GALLERY AT MESSRS. POPE & PEARSON'S COL- 
LIERIES, ALTOFTS, ON MARCH 23rd, 1907. 
The following programme had been arranged to be carried 
t)ut before the members of the Midland Institute of Mining, 
Civil and Mechanical Engineers by two teams: one consisting 
of four men from Messrs. Pope & Peai^on, Limited's collieries, 
wearing the Weg apparatus; the other of four men equipped 
with the Draeger apparatus from the Tankersley rescue-station, 
belonging to the Barrow Hematite Steel Company, Limited, 
Messrs. Newton, Chambers & Company, Limited, the Strafford 
Collieries Company, Limited, and the Wharncliffe Silkstone 
Colliery Company, Limited : — 

(1) Four men to enter the gaUery, walk 100 yards, and creep on hands and 
knees, 50 yards. 

(2) The same four men to pick up a stretcher, weighing 40 pounds, carry it 
through narrow roadways, over falls, at the same time removing stones, varying 
from 40 pounds to 80 pounds in weight ; then crawl through an air-pipe, 2 feet in 
-diameter and 6 feet long. Pick up dummy man, 160 pounds in weight, place him 
on the stretcher, and carry the loaded stretcher back to the entrance of the gallery. 

(3) Two of the rescue-teaui to return to the farthest point of the gallery, 
•carrying fire-extincteurs, and discharge the contents of the same on the windows, 
in imitation of extinguishing a supposed underground fire. When this work is 
completed, they will occupy the rest of the time in fixing brattice.cloth, setting 
props and bars, and other work useful for exploration. 

(4) The remaining two men of the team will repeatedly lift a weight of 56 
pounds to a height of 6 feet. 

The Council of the Midland Institute of Mining, Civil and 
Mechanical Engineers arrived at the colliery about 10'30 a.m. ; 
and a committee was formed, consisting of the following 
members: — Prof. Q. R. Thompson, Messrs. "VV. Walker, J. R. R. 
Wilson, H. B. Nash, J. E. Chambers, J. J. Eley and J. Gill, who 
supervised the work done by the two teams wearing respectively 
the Weg and the Draeger apparatus. It was agreed that a coin 
should be tossed, to show which team should enter the gallery 
first ; and the choice indicated the Weg apparatus. 



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210 REPORT OX RESCUE-WORK. 

I. — The following is a detailed record of the work done by 
the team of four men wearing the Weg apparatus : — 

12*17 p.Tn. Entered the gallery. 

12-20 p.m. Walking 80 yarcU. 

12*23 p.m. Creeping 80 yards. 

12*27 p.m. Went over the falls, clearing a way for the stretcher, and brought 
ont the dummy man at 12*46 p.m. 

12-49 p.m. Nob. 1 and 4 men went over the falls with fire • extincteurs, 
through the air-pipe, discharged one fire-extinctenr, and returned over the falls 
carrying fire-extincteurs to the nursery or entrance of the gallery. 

12*53 p.m. Nos. 2 and 3 men commenced pulling the weight. 

1 '0 p.m. Nos. I and 4 men went over the falls, through the air.pipe, with 
three rolls of brattice-cloth, a hammer and nails. They fastened up the brattice, 
cloth in a form representing a mid-feather, to improve or alter the ventilation,, 
and returned over the falls to the nursery at 1*15 p.m. 

1 '15 p.m. Nos. 1 and 4 men went over the falb carrying two fire-extincteurs, 
through the air-pipe, and returned over the falls to the nursery. 

1*25 p.m. Nos. 1 and 4 men travelled under the falls, and returned over the 
falls to the nursery. 

1*41 p.m. No. 1 man walked 96 yards, and came out of the gallery owing ta 
a break-down in the apparatus ; and, the defect being adjusted, he re-entered the 
gallery at 1*55 p.m. 

1*45 p.m. No. 4 man travelled over the falls and under the falls, back to the 
nursery, with a fire-extincteur. 

1*58 p.m. No. 1 man travelled over the falls, through the air-pipe, and 
under the falls, back to the nursery. 

2*5 p.m. Nos. 1 and 4 men travelled over the falls with fire-extincteurs,. 
through the air-pipe, and returned through the air-pipe, and over the falls to the 
nursery. 

2*27 p.m. No. 1 man travelled over the falb with a fire-extincteur, and back. 

During this time, No. 2 man had lifted the weight 337 times and No. 3 man 
had lifted it 251 times, or a total of 588 times, equal to 197,568 foot-pounds 
of work. 

After the team had been in the gallery for 2 hours and 15 minutes, they were 
requested to come out, as this time had been agreed upon by the Committee as the 
limit of the trial. The men had understood that they were to stay in as long as 
they possibly could, and were surprised at the request ; and the leader wrote a 
note saying that No. 3 man could stop in about 20 minutes. No. 2 man about 15 
minutes, and No. 1 man about 10 minutes, and that No. 4 man had nearly 
exhausted his supply of oxygen. After this, each man walked 336 yards. 

2*42 p.m. No. 4 man came out of the gallery, having finished his supply of 
oxygen, and he had been 2 hours and 25 minutes in the gallery. 

2*45 p.m. No. 1 man came out of the gallery, oxygen finished. 

2*46 p.m. Nos. 2 and 3 men were told to come out of the gallery. Their 
oxygen -supply was not finished ; No. 3 man had a pressure of 40 atmospheres left 
in one cylinder. Their time in the gallery was 2 hours and 29 minutes. 

II. — Men wearing the Draeger apparatus entered the gallery 
at 3*5 p.m. Xos. 1 and 2 men were wearing the new Draeger 
mouthpiece, and Nos. 3 and 4 men the Draeger helmet. 



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REPORT ON RESCUE-WORK. 



211 



3-5 p.m. Walking 96 yards. 

Creeping 96 yards. 

Went over the falls, clearing a way for the stretcher, and brought out the 
•dummy man at 3*32 p.m. 

3*34 p.m. Nos. 1 and 2 men went over the falls and through the air-pipe, 
■and returned over the falls to the nursery ; but only one man went through the 
■air-pipe. 

4*0 p.m. Nos. 1 and 2 men went over the falls with brattice-cloth ; No. 1 
man came back over the falls for the hammer, fastened up the brattice-cloth 
similarly to No. 1. team, and returned at 4*20 p.m. to the nursery. 

4*25 p.m. Nos. 1 and 2 men went over the falb, and back to the nursery at 
4*34 p.m. 

4*39 p.m. No. 1 man went over the falb to the sixth door,^', and No. 2 man 
•as far as the fourth door, ft, and returned to the nursery (fig. 1, plate viii.). 

4*44 p.m. No. 2 man came out, having been in the gallery 1 hour and 39 
minutes. 

During this time, Nos. 3 and 4 men had lifted the weight 762 times, equal to 
1256,032 foot-pounds of work. 

5*6 p.m. No. 3 man came out, oxygen finished, having been in the gallery 2 
hours and 1 minute. 

5*22 p.m. Nos. 1 and 4 men were told to come out of the gallery. They had 
been in for 2 hours and 17 minutes, and they still had enough oxygen to last 
for a few minutes longer. 

III. — The following is a summary of the work done in a 
noxious atmosphere, by ih© men equipped with the following 
forms of apparatus : — 



Occupation of Men. 

Walking 

Creeping 

Travelling over falls 

Creeping through contracted passages 

Creeping through air-pipe 

Carrying fire-extincteurs 

Fixed brattice to alter ventilation 

Lifting 56 pounds weight to a height of 6 feet 

Foot-pounds of work 



Apparatus used: 


Weg. 


Draeger. 


1,760 yards. 


384 yards.* 


320 „ 


384 „ 


600 „ 


570 „ 


80 „ 


— 


23 times. 


14 times. 


8 „ 


2 „ 


Once. 


Once. 


588 times. 


762 times. 


197,568. 


256,032. 



Mr. M. H. Habebshon read the following paper on "The 
TJse and Care of Oxygen-breathing Apparatus " : — 



* Mr. M. H. Habershon discusses these results, Trans, Inst, M. E,^ 1907, 
voL xxxiii., page 233. 



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212 USE AND CARE OF OXYGEN-BREATHING APPARATUS. 



THE USE AND CARE OF OXYGEN-BEEATHING 
APPARATUS. 

By M. H. HABERSHON. 



In view of the probability that, in the near future, stations 
will be established in various places for the purpose of trainings 
men in the use of oxygen-breathing* apparatus, and at which 
such apparatus may be kept in readiness for any emergency, 
it is thought that the following notes of the experience which 
has been gained during the last few years at the Tankersley 
rescue-station may be of interest to the members. It is not 
intended to describe the various types of apparatus, as this has 
been done so recently by Mr. G. A. Meyer,* Mr. W. E. Garfortht 
and Mr. R. Cremer.J 

The subject of rescue-appliances has been more or less before 
this and other mining institutes for some time ; but the dispatch 
of the Westphalian rescue-party to Courrieres collieries, and the 
rescues effected at the recent Reden disdsterg have brought the 
matter into greater prominence. It may therefore be assumed 
that members are familiar with the arguments or considerations 
which point to the necessity of appliances being kept and main- 
tained in readiness for use when suddenly required, and the equal 
aecessity of men being trained to use them.ll 

For the present purpose it is only needful to state that the 
essential conditions which must be satisfied are the following : — 

* "Rescue-apparatus and the Experiences gained therewith at the 
Courrieres Collieries by the German Rescue-party," by Mr. G. A. Meyer, Trans. 
IiisL M, E,, 1906, vol. xxxi., page 575. 

t " A New Apparatus for Rescue- work in Mines," by Mr. W. E. Garforth, 
Trans. Inst, M. E., 1906, vol. xxxi., page 625. 

X '*The Pneumatoeen : the Self -generating Rescue-apparatus, compared 
with Other Types," by Mr. R. Cremer, Trans. Inst. M. E., 1906, vol. xxxii., 
page 61. 

§ ** Rescue-apparatus in Mines," by Mr. Richard Jacobson, The Colliery 
Guardian J 1907, vol. xciii., page 317. 

II **A Joint Colliery Rescue-station," by Mr. M. H. Habershon, Trans. 
Inst, M, E., 1901, vol. xxi., page 100. 



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USE AND CARE OF OXYGEX-BEEATHING APPARATUS. 213- 

(a) The apparatus must be conveniently at hand, (b) The appar- 
atus must be in perfect working order, (c) The men must be 
thoroughly conversant with the handling of the apparatus, and 
not merely accustomed to wearing it. (d) The instructor or man 
in charge of the apparatus must be thoroughly trained, not only 
in wearing and handling the apparatus, but also in cleaning it 
and testing the various parts for imperfections and leakages. No 
ordinary caretaker, without special training in the construction 
and principles of oxygen-breathing apparatus, is capable of 
occupying this position. The instructor employed at the- 
Tankersley rescue-station had, through the kindness of Mr. G. A.- 
Meyer, the opportunity of going through a course of instruction 
at the Shamrock colliery, and made himself thoroughly acquainted 
with every detail of the apparatus in use there at that time, and 
also of the organized work which is systematically carried on in 
connection with the Hibernia collieries. 

In order to estimate properly the importance of the various 
points to which the writer proposes to call attention, the follow- 
ing preliminary considerations must be stated. The three 
chief desiderata in oxygen-breathing apparatus are as follows: — 
(1) Complete absorption of the carbon dioxide. (2) Sufficient 
provision of air for the lungs to allow of the performance of hard 
work by the wearer. (3) Simplicity of construction. 

As in ordinaiy breathing the lungs consume oxygen and 
produce carbon dioxide, an artificial breathing-apparatus must 
produce oxygen and absorb the carbon dioxide, and the various- 
types of apparatus all have this end in view. But it is important 
to notice that the lungs have a large surface for supplying the^ 
necessary amount of oxygen to the blood, and the apparatus, 
being a counterpart to the lungs, should have a large surface for 
absorbing the carbon dioxide. As, in natural breathing, oxygen 
is conveyed to the lungs by the aid of the respiratory movements 
of the muscles of the chest, the artificial apparatus must possess 
some motive power to bring about a similar action. This is 
supplied by means of the injector in the Shamrock, Giersberg 
helmet and Draeger apparatus. The compressed oxygen, passing 
through the injector, establishes a suction which forcibly draws 
the exhaled air through the regenerator and round to the injector,, 
where it merges with the fresh oxygen and is then carried forward" 



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:214 USE AND CARE OF OXYGEN-BREATHING APPARATUS. 

for inhalation. The injector thus establishes a continuous circu- 
lation of the air in the apparatus. 

The necessary supply of oxygen must not be taken as the bare 
amount actually required for the lungs alone; but a surplus 
should be provided in order to allow for leakages, so as to ensure 
that the quantity available shall always be sufficient for the 
possible requirements of the wearer. It has been ascertained 
that a continuous supply of 122 cubic inches (2 litres) per minute, 
is sufficient not only to meet the requirements of heavy work, 
but also to ensure that the immediate needs of the wearer shall 
Tdc constantly supplied. 

The amount of carbon dioxide produced in the lungs has 
generally been underestimated. A man doing heavy work will 
exhale rather more than 6,100 cubic inches (100 litres) of carbon 
dioxide in 2 hours. For information on this point members are 
referred to the paper by Dr. J. S. Haldane and Mr. T. Lorraine 
Smith, on " The Physiological Effects of Air vitiated by Respira- 
tion,''* from which the following conclusions have been 
•drawn: — Respiration becomes difficult when the percentage of 
carbon dioxide in air exceeds 4, with 10 per cent, the possible 
limit is reached. Breathing air containing 4 to 10 per cent, of 
carbon dioxide brings on pains and throbbing in the head, 
accompanied by vomiting. Xo ordinary excess of oxygen will 
remove the consequences of breathing this high percentage of 
•carbon dioxide. With an insufficient supply of oxygen, difficulty 
in breathing first becomes noticeable when the percentage is 
reduced to about 12, and with 6 per cent, the difficulty is 
excessive. It has been assumed that a volume of 3,050 to 3,660 
cubic inches (50 to 60 litres) of air at disposal during heavy 
work would be sufficient ; but^ when a man is breathing heavily 
nfter a period of unusual exertion, during a few seconds the 
timount of air required by him is considerably increased, and it 
is probable that 6,100 cubic inches (100 litres) may be utilized. 

The above figures give some idea of the requirements that 
have to be met by an oxygen-breathing apparatus, if it is to be 
reliable under all the conditions in which it is likely to be 
placed. A rescue-apparatus, therefore, should be capable of 
complying with the above-mentioned conditions, in addition to 
Jiaving the simplicity of construction which has been referred 

• Tht Journal of Pathology and Bacttriology^ 1892, vol. i., page 168. 



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USE AND CARE OF OXYGEN-BHEATHING APPARATUS. 215 

to as onje of the chief desiderata ; aad it may be considered satis- 
factory or not in proportion to its behaviour when judged accord- 
ingly. Other matters^ such as facility for cleaning* and dura- 
bility, are important, as they effect the second essential condition 
above stated, also the necessary consideration of cost of main- 
tenance ; but they should not be allowed to interfere too much in 
selecting a type of apparatus. There are, however, several 
•details which have an influence both on the question of satisfying 
the essential requirements and on the possibility of keeping 
the apparatus in proi)er working order, and it is chiefly to these 
•details that the following notes refer. 

The first apparatus used at the Tankersley rescue-station was 
of the Giersberg 1901 type with two cylinders : it was exhibited 
to the members of the Institution by Mr. G. A. Meyer on the 
occasion of their visit to the Dusseldorf exhibition and the 
Westphalian coal-field. Subsequently a three-cylinder appar- 
atus, of the Giersberg-Shamrock type, embodying several im- 
portant improvements, which Mr, Meyer had introduced, was 
obtained ; and, at a later period, the Giersberg-Shamrock 1906 
type, with two cylinders and additional improvements, as used by 
Mr. Meyer at the Courrieres collieries. On the strong recom- 
mendation of the makers, the Giersberg helmet-apparatus was 
also procured. And, more recently, the Draeger apparatus, 
arranged for either mouth-breathing or use with a helmet, had 
been used, in consequence of the powerful regenerators with 
which this apparatus is supplied. Attention had been directed 
hy Mr. G. B. Walker to this apparatus in 1904 * The pneu- 
matogen had also been tried. 

The writer was fully aware of the decided preference expressed 
by Mr. G. A. Meyer at the London meeting in 1906, for appar- 
atus of the mouth-breathing type, but he had found that men 
wearing a helmet or face-mask of the latest construction, with 
separate tubes for inhaling and exhaling and powerful regenera- 
tors of the Draeger type, were able to perform really hard work, 
and to crawl through a length of air-pipe, 2 feet in diameter, 
without any distress whatever ; and that at the end of 2 hours 
the apparatus would still deliver air to the wearer free from 

• Olilcka^f, 1904, vol. xL, page 1331 ; and Trans, hist, M, K, 1904, vol. 
jcxviii, page 203. 

VOL. zxxni.~i9oe-i907. 17 



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216 USE AND CARE OF OXYGEN-BEEATHING APPARATUS. 

carbon dioxide, without any liability to headache as formerly. 
This apparatus is also arranged for mouth-breathing; 
but it has been found that a greater amount of training is 
necessary for mouth-breathing, and that many men seem to have 
a reluctance to having their nostrils closed in a suflSiciently 
secure manner to ensure satisfactory results with the mouth- 
breathing arrangement, and have a preference for the helmet. 
The writer thinks that in this country, where the work is done 
by the men voluntarily, the question of helmet or mouth-breath- 
ing may, for the present, be considered as a detail which will be 
more easily decided after greater experience, and that men should 
be trained in the use of both types, as there are distinct advan- 
tages appertaining to each. The opinion of Mr. G. A. Meyer 
on this point deserves our greatest respect and consideration; 
but improvements are developing constantly, and the writer has 
seen hard work done with a helmet-apparatus under most trying 
conditions, work which could not have been beaten or so easily 
done with the mouth-breathing apparatus. He thinks that^ 
probably as recently as a year ago, this would not have been 
possible. 

The improvements effected, which the writer considers to be 
of decided merit, include an apparatus that can be fitted 
up for either mouth-breathing or helmet; the complete absorp- 
tion of all moisture ; no liability of any liquid alkali getting into 
the breathing-tubes ; air delivered free from carbon dioxide after 
2 hours' work ; time required for recharging reduced to about 8 
minutes ; no assistance required ; and the wearer can be 
trained to ascertain for himself the amount of oxygen still at 
his disposal, and so to time himself. In case of apparatus used 
for a short time only, the remaining alkali is not wasted. 

In the use and care of the various appliances, the following 
are the points which the writer wishes to bring under the notice 
of the members. 

In cleaning the Giersberg apparatus of the Shamrock type, 
after use, attention should first be given to the breathing-bag. 
The mouth-piece with the attached metal tubing and also the 
escape-valve must be removed, then the regenerator should be 
taken out of the inner part of the breathing-bag. All alkali 
(caustic potash) and kieselguhr must then be removed, and the 



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USE AND CAEE OP OXTGEN-BEEATHING APPARATUS. 217 

holders of the same washed. The breathing-bag must be washed 
perfectly clean, all sediment being removed, and a mild disinfect- 
ant should be used with the water. The bag should then be^ 
allowed to dry naturally ; no forced method of drying should be 
adopted. When dry, the passages of the breathing-tube, suction 
and escape-valve tubes must be ascertained to be perfectly clean. 
The suction and escape tubes should then be laid on the top of the 
inner bag, as neglect of this might result in the buckling of these 
tubes during subsequent handling, and give rise to a stoppage in 
the working of the apparatus. The regenerator must then be 
refilled with alkali, and the lower portion with kieselguhr. The 
inner bag must be examined, in order to see that the holes in the 
bottom are perfectly clear. The regenerator should then be re- 
placed, the clamps securely fastened, the escape-valve and tubes 
attached, and the mouth-piece should be plugged. The appar- 
atus, being then ready for use, should be hung up. This complete 
operation requires at least i day on account of the time required 
for the drying of the breathing-bag. 

In the Giersberg helmet-apparatus, the mica valves for 
inspiration and expiration should be carefully inspected both 
before and after use, as upon these depends, in a great measure, 
the proper working of the apparatus. The mica discs and cups 
must be perfectly dry, as any quantity of moisture may cause 
these valves to stick. Sufficient room must be allowed in these 
cups for the valves to move freely, particularly in the case of the 
expiration-valve : the regulation of this is easily effected by the 
two screw-caps above and below the mica discs, but care must be 
taken not to screw these caps too tightly. Before use, the con- 
dition of these valves should be tested by placing the helmet on 
the head securely and drawing several breaths in quick succes- 
sion, at the same time listening for the click of these valves, 
which should accompany each inspiration and expiration. The 
escape-valve should be examined, to see that it will blow off upon 
a slight compression of the expiration-bag. The pneumatic 
lining of the helmet and it^ valve should be carefully examined 
on each occasion for possible leakages, and any defect immedi- 
ately attended to. The breathing-bags should be washed and 
disinfected occasionally, and allowed to dry before they are again 
used. The regenerator should be washed out after use, great 
care being taken to see that the passages connecting the two 



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218 USE AND CAKE OF OXYGEN-BREATHING APPARATTTS. 

chambers are perfectly clear and free from any sediment. The 
flexible tubing should not be handled in too reckless a manner, 
else injury of a permanent ch«iracter may be caused *; and these 
tubes, being of special construction, are not easily replaced. 

In the Draeger helmet-apparatus, owing to the different 
arrangement of the valves in the helmet, the same amount of 
attention to the valves is not so necessary. In the writer's experi- 
ence of this apparatus, the valves have never been known to 
stick, indeed any sticking of the valves in this apparatus seems 
improbable, if not impossible ; but the writer thinks that some 
provision should be made by the makers, so that these valves can 
be replaced in the event of the mica plates or discs becoming 
defective. As at present constructed, they cannot be easily got at. 
The pneumatic lining of the helmet and its valve, as also the 
breathing^bag, should have the same attention as in the case of 
the Giersberg apparatus. 

In the pneumatogen, in which oxygen is generated by passing 
the expired air through cartridges containing layers of potassium- 
sodium peroxide, by which also the carbon dioxide is taken up, 
there are no valves and no oxygen-cylinders, a small quantity of 
oxygen only being required to start the chemical action. Conse- 
quently the apparatus is extremely simple, and the amount of 
attention required is reduced to a minimum. 

After the pneumatogen has been used, the exhausted cart- 
ridges are removed, the upper and lower transverse tubes should 
be cleaned out, and any particles of carbonate found adhering 
thereto must be removed. After recharging with fresh cart- 
ridges, any screws which have been loosened for cleaning pur- 
poses must be firmly screwed down. The cartridges must be 
placed in their proper position, and the handle of the upper 
transverse tube pushed down into its right place. The breathing- 
bag should be washed and disinfected occasionally. The tight- 
ness of the apparatus may be tested by closing the mouth of the 
lower transverse tube with the hand and at the same time blowing 
into the mouth-piece. 

The circulating system of all apparatus should frequently be 
tested for leakages by blowing into the breathing-tube: the 
valves of the oxygen-cylinders being closed, thus throwing the 
apparatus out of action, and using the thumb to close the open 
end of the tubing, which may have been disconnected for the 



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USE AND CARE OF OXYGEN-BREATHING APPARATUS. 219 

purpose of testing. When in action, a solution of soap and 
water applied to the joints with a brush or sponge will reveal 
any leakage by the appearance of a small bubble. The valves 
of the oxygen-cylinders may also be tested for any suspected 
leakage of oxygen by submerging the cylinders in water. An- 
other method of testing for oxygen-leakages is by the red-hot 
embers of a match. 

Care must be taken to prevent any greasy substance coming 
in contact with any cylinder or fitting used for the storage or 
control of oxygen. For instance, the valves of oxygen-cylin- 
ders must not be oiled, no lubricant whatever that is of a greasy 
character must be used. Globe polishing-paste must not be used 
for the brass fittings or any part of the apparatus. 

No part of an apparatus requires more attention from the 
man in charge than the injector, which, as explained above, 
supplies the motive power and maintains the circulation of the 
gases in the apparatus. This should at all times be kept under 
careful observation. The eflSiciency of the injector is liable to be 
affected by oxidation arising from the chemicals used for the 
absorption of the carbon dioxide, and also by obstruction, which 
may result from various causes. Any small particles of matter 
are sufficient to cause a partial blockage, and interfere with the 
proper working of the injector. 

When the cylinders of the apparatus are charged with oxygen 
from a large storage cylinder, and an hydraulic pump is used in 
order to obtain the necessary high pressure of 120 atmospheres, 
the oxygen being removed from the storage cylinder by displace- 
ment with water, a grave danger is likely to arise which must be 
guarded against. The oft-repeated operation, in time, produces 
an accumulation of rust, and there is the possibility of small 
particles of rust being conveyed into the cylinder of the appar- 
atus, whence they are only prevented from entering the 
injector by a thin gauze. If this gauze should be pene- 
trated, a partial or complete blockage of the injector may 
be produced. If the rust does not reach the injector it will prob- 
ably accumulate in the reducing valve, but the result will be 
the same — the apparatus will not work properly. Another and 
more subtle liability to danger exists with the method of charging 
the cylinders. Water may pass into the small cylinders during 
the act of charging. This is unknown to the operator, and its 



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^20 USE AND CABE OF OXYGEN-BEEATHIXG APPABATUS. 

presence may not be revealed or suspected. An apparatus may 
thus work perfectly for some considerable time, but after a while 
a bubbling sound will be beard and the injector will act 
spasmodically. Ultimately, an abrupt and premature stoppage 
of the action of the apparatus may result. If the wearer at this 
moment happened to be in an irrespirable atmosphere, he would 
require the assistance of his comrades, or the apparatus might 
be only a death-trap. 

The operation of charging small cylinders from a large 
storage cylinder by means of an hydraulic pump worked by hand 
is very laborious, the time required is considerable, and there 
are newer and improved methods of charging oxygen-cylinders 
which should be adopted in preference, and with which the above- 
named liability of water passing into the cylinders is avoided. 

In the event of an injector becoming faulty from oxidation 
or deposit, no hard or sharp tool should be used to clear the 
offending matter, as damage to the injector may be easily caused 
in this way, but the injector should be soaked and more gentle 
means tried. Injectors should be under such close supervision 
that no oxidation should ever be allowed to accumulate, but 
the defect discovered and remedied upon the first indication of 
any fault of this nature. Owing to the delicate mechanism of 
the reducing valve, it is desirable that a perfect knowledge of its 
construction should be acquired before any attempt is made to 
remedy any defect which may be discovered. 

Injectors and regulating valves should be included among 
the necessary spare parts which should be kept at a rescue- 
station. 

All metal tubing on the apparatus should receive close 
examination from time to time, and be kept perfectly clear from 
sediment. 

The indiarubber breathing-bags and tubes should be kept 
moist and not allowed to get dry, or the rubber will lose its 
proper character and the bags will crack and become leaky, par- 
ticularly at points where any buckling takes place when they are 
in use. The usual routine of washing and disinfecting the bags 
is generally sufficient to keep them in good condition, provided 
that they are used in rotation, and are not allowed to remain idle 
for too long a period. All apparatus in any station should be used 
strictly in rotation, and in an equipment consisting of, say, 20 



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USE ANB CAEE OF OXYGEN-BEEATHING APPARATUS. 221 

sets, five sets should always be ready for immediate use, and 
before they are used for practice purposes another set of five 
must be prepared to replace them. This being strictly attended 
to, it will keep an equal working strain on each set of apparatus, 
and will provide for any emergency. A station would in this 
way be ready at all times to answer and keep up any call on its 
resources, every apparatus in its turn would come under the 
notice of the man in charge, and there would be ample time for 
the work to be done carefully, and without hurry. 

It is a good plan to test the circulation of the apparatus, 
from time to time, by means of a linen bag made to contain 
from 2,440 to 3,050 cubic inches (40 to 50 litres) of air, and this^ 
quantity should be passed into the bag from the apparatus in 
1 minute. The air which is being delivered for breathing 
should also be tested periodically for carbon dioxide when the 
apparatus is in use. This is easily done by means of a special 
fitting and a syringe, with which a sample can be taken and 
injected into a solution of lime-water, wheu, if turbidity is 
produced, carbon dioxide is present. 

In training men, no work of any kind beyond gentle exercise 
should be attempted during the first and second practices, but 
the time should be devoted to instruction in the principle of the 
apparatus and explanation of the various parts and the circula- 
tion of the air. The men should be shown how to handle the 
apparatus, and practised in the operations of putting it on and 
taking it off. With helmet-apparatus, the opening and shutting 
of the helmet-window should be well practised, until the men are 
thoroughly at home in so doing. The accomplishment of any 
kind of work must be approached very carefully and by degrees, 
especially with the mouth-breathing apparatus, with which more 
practice is usually required in order to become proficient. Suit- 
able men can, however, obtain efficiency with this apparatus in 
a few weeks, but without occasional subsequent practice the 
efficiency will be lost, and the men will be surprised that they 
are not able to wear the apparatus and do work as easily as they 
anticipated. With the Draeger helmet-apparatus, a man having 
become thoroughly trained would probably be able to use it after 
a short lapse of time without intermediate practice. 

In a fully equipped station, it would be advisable for men to 



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222 DISCUSSION — USE AND CARE OF OXYGEN-BEBATHING APPARATUS. 

practise in sets of five, so as to get accustomed to work together 
under a leader. In addition to practices at a station, wluch 
should involve hard work in a noxious atmosphere so as to give 
confidence in the efficiency of the apparatus, it is desirable that 
men who have been trained and are efficient should occasionally 
have an opportunity of wearing the apparatus underground, for 
which purpose each colliery connected with a station should 
organize a pit-practice, say, once every three months. 



The President (Mr. J. R. R. Wilson), in proposing a vote 
of thanks to Mr. Habershon for his paper, pointed out the extreme 
importance of such a paper at a time when the question of 
rescue-stations was attracting so much attention. 

Prof. G. R. Thompson said that all who were present at the 
meeting at Altofts colliery were perfectly satisfied that rescue- 
apparatus would be of use in mines. Recently, it had been con- 
tended that the only way of dealing with a mine aft«r an explo- 
sion was for the explorers to carry in the air with them. Every 
miner would admit that the restoration of the ventilation was what 
they wished to accomplish, and they had seen at Altofts colliery 
the most convincing evidence that vigorous work was possible in 
a poisonous atmosphere, when using either the Draeger or the 
Weg apparatus. Surely such appliances would enable them to 
re-establish the ventilation much more readily. Mr. Habershon 
had given the members careful details of the steps to be taken 
so as to ensure that the apparatus should always be ready for 
use ; and, if his methods of testing and supervision were rigidly 
adhered to, no fear need be entertained that the apparatus would 
fail when required. He regretted that accurate information wae 
not recorded in mining text-books, regarding the effects of varia- 
tions in the composition of the atmosphere breathed, and he 
wished that Mr. Habershon had told the members more on that 
point. It was, however, stated that an increase in the amount 
of carbon dioxide produced ill-effects, which could not be re- 
moved by increasing the amount of oxygen ; and that a deficiency 
of oxygen, apart from the presence of carbon dioxide, was also 
harmful. The methods of absorbing the carbon dioxide generated 
in breathing seemed sufficiently perfect in the newer forms to 
keep it below injurious proportions ; but he asked whether there 



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DISCUSSION — ^USE AND CAEE OF OXYGEN-BEEATHING APPARATXTS. 

was any danger of the nitrogen, in the compressed oxygen used, 
accumulating in the Weg apparatus to such an extent that the 
deficiency of oxygen would become serious. He had much plea- 
sure in seconding the vote of thanks. 

Mr. W. McD. Mackey, referring to the breathing and re- 
breathing continuously of one charge of nitrogen, said that a 
man continually for months or years breathing nitrogen, or 
rather air, under the conditions obtaining in rescue-apparatus^ 
would certainly weaken his lungs and become liable to consump- 
tion ; that was, the organic matter continually breathed out of 
his lungs would accumulate and bring on some sort of poison- 
ing. But, in an apparatus of this kind, used for a short time 
only, he thought that the matter was of no importance. 
He supposed that the point raised by Prof. Thompson had 
been dealt with before: he was not aware that provision had 
been made to get rid of any excess of nitrogen, but he supposed 
that it was so. Compressed oxygen in cylinders contained not 
less than 2 per cent, of nitrogen, and it might rise to 4 per cent, 
and even more. Of course, under these conditions, if nitrogen 
accumulated in the apparatus, the percentage would become very 
high in the course of a few hours. Looking at it from the 
chemical standpoint, he (Mr. Mackey) liked the pneumatogen, 
as it seemed very simple. It had the objection that it became 
too warm ; but it was light, and mechanically simple. He asked 
if there were any data by which a comparison could be made 
between the pneumatogen and the other forms of apparatus! 

Sergeant A. T. Winborn said that Mr. Paul Henaud had 
stated that the period during which the pneumatogen could 
be used was too short, and that it was liable to cause sickness 
owing to the amount of carbon dioxide present,* and Mr. H. 
Orahn, of the Bochum mining school, had reported that, where- 
as no ill effects were experienced from the use of the Draeger 
apparatus, the men wearing the pneumatogen frequently com- 
plained of pains in the head.t In the very limited experience 
at Tankersley with this apparatus, there had been no 

* Comptes Beiidus Jfeimiels des Reunions de la Soci4t6 de VIndxistrie Mhidralt^ 
1907, page 6S. 

t ** Bericht fiber Versuche mit Rettungsapparaten und ttber deren Verbea- 
senmgen" (Experiments with Rescue-apparatus), by Mr. Hermann Grahn 
Oluckauf, 1906, vol. xlii., page 665. * 



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224 DISCUSSION — USE AND CARE OF OXTGEN-BREATHING APPARATUS. 

complaints from this source, but complaints had arisen from 
the over-heating of the apparatus, brought about by the 
generation of oxygen. He (Mr. Winbom) thought that the 
first type of pneumatogen, even in its present condition, formed 
an almost necessary part of the equipment of a rescue-station, 
as they could be used by a rescue-party in connection with the 
bringing out of men who might need such assistance. 

The theoretical principles of different types of apparatus had 
been explained, as also particulars of tests made with them ; but 
the actual number of men who had become efficient, out of a given 
number undergoing instruction, in the use of any particular 
type of apparatus had rarely been given in discussion upon this 
subject. During his experience as instructor at the Tankersley 
rescue-station, he had learned to judge an apparatus according 
to the number of men that he had been able to get to wear it in an 
efficient manner. He thought that the opinion of the men them- 
selves went a long way in estimating the value of an apparatus. 
They had to put up with any discomfort which might arise 
through wearing it, and they would be the very first to find out 
flaws or imperfections. He considered that the best testimonial 
which any apparatus could have was the decided preference 
shown for it, over other types, by the men who had to wear it. In 
his opinion it was not sufficient to have at each pit a few men who 
could wear an apparatus. The difficulty in getting such men 
upon the spot when wanted would be great, and too lai^ly a 
matter of chance ; and, at a time of disaster, these men might be 
in the pit, and themselves in need of succour. An apparatus 
was wanted such as the maximum number of men could wear, 
with the minimum amount of practice to attain proficiency. All 
men were not alike constitutionally. Some could wear an appar- 
atus for a long period, and perform a creditable amount of work ; 
whereas others could wear precisely the same apparatus only for 
a short time, and the wearing was then often accompanied by 
ill after-effects. Gb'eat strides had been made in the last few 
years in perfecting the system of regenerating the exhaled air, 
and all types of apparatus were much more perfect to-day than 
a few years ago. For instance, during 1904, out of 70 men 
attending for instruction in the Shamrock type of apparatus, 
barely 10 per cent, attained efficiency. During 1906, out of the 
same number of men receiving instruction in the same type of 



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DISCUSSION — USE AND CARE OF OXYGEN-BEE ATHING APPARATUS. 226 

apparatus, 60 per cent, became eflScient. But, in spite of improve- 
ments, there still existed this distinction as between different types 
of apparatus, that although 60 per cent, could wear one apparatus, 
only 40 per cent, of the same men could wear another type of 
apparatus in anything like a satisfactory manner. With regard 
to the Draeger type of apparatus, all the men attending instruc- 
tion last year were able to wear it for the full period ; and he had 
yet to find the man, constitutionally suitable, who could not wear 
it. The value of such an apparatus, where a large number of 
men had to be trained, was inestimable. 

He had seen the new Shamrock apparatus, which comprized 
many important improvements. It could be used either as a 
mouth-breathing apparatus, or with a helmet; the latter having 
the additional advantage of being valveless. The position of the 
injector had been altered, thus minimizing the possibility of any 
matter effecting a lodgement therein, such as to impede its 
proper working. The regenerator, instead of being carried inside 
the breathing-bag, was now carried outside and on the top of it. 
The apparatus could be recharged in a few minutes, by substitut- 
ing a fresh regenerator for the used one, which could be recharged 
with the necessary alkali at leisure and used again, and so on 
indefinitely. The Draeger also had this advantage, excepting 
that the cartridges or regenerators were discarded altogether after 
being used. The oacygen-cylinders of the new Shamrock appar- 
atus were now nickel-plated inside, as a precaution against the 
accumulation of rust. A trap was placed at the outlet-end to 
collect any foreign matter, which otherwise might find its way 
into the reducing valve or injector. 

Mr. W. D. Llotd (Altofts Colliery), on behalf of himself and 
the men at Altofts, said that he was much gratified by the thanks 
of the members. He thought that there were many points about 
the oxygen-supply, which required carefully looking into. He 
agreed with Mr. Habershon in regard to the question of the 
recharging of cylinders by pumping water into the storage- 
cylinders; Messrs. Draeger had introduced an apparatus which 
overcame that difficulty, but there still remained the difficulty of 
the moisture in the oxygen. He recently had occasion to 
measure the cubical contents of a cylinder by filling it with 
water : when the water was poured out, it was absolutely red with 



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226 DISCUSSION — USE AND CAEE OF OXYGEN-BREATHING APPARATUS* 

rust, and, after standing, there was a considerable deposit. The 
accumulation of rust in the cylinder was a very serious matter, 
because reducing valves of some sort and small passages with 
wire-gauze protections were unavoidable in any apparatus ; and 
this rust was liable to get into the passages, and block them 
so as to render the apparatus inefficient, and possibly cause the 
death of a man wearing the apparatus. He could corroborate 
Mr. Mackey's statement that ordinary commercial oxygen con- 
tained from 2 to 4 per cent, of nitrogen : there was often 6 per 
cent, and sometimes more in it; and he had known as much as 
10 per cent, of nitrogen to be present. Only a small volume of 
OKjgen was carried in the apparatus, and if 10 per cent, were 
nitrogen, it became a very serious matter. He most strongly 
pleaded foK as pure a supply of oxygen as possible. He believed 
that some of the methods of manufacture were within the scope 
of rescue-stations, and he hoped that they would be able to make 
their own. 

Dr. J. S. Haldane, when testing the Weg apparatus at 
Altofts, expected to find that an excess of nitrogen might, at 
times, be present. Dr. Haldane laid stress on the point that, if 
a man got too much nitrogen or there was a deficiency of oxygen, 
it would not be noticed in the breathing.* The man would go 
on breathing it until he became blue in the face and fell down, 
but he would not experience any difference in his breathing. 
The smallest percentage of oxygen found in the Weg apparatus 
by Dr. Haldane was 14 per cent., and this meant, of course, 
that there was 86 per cent, of nitrogen ; and, adopting the per- 
centages quoted by Mr. Habershon, this was still a breathable 
atmosphere, although the air analysed was obtained from the 
back bag or reserve-supply, which should be renewed with more 
oxygen before being breathed again. He thought that Dr. 
Haldane had obtained as high as 60 per cent, of oxygen. 

A point for discussion was that the apparatus described by 
Mr. Habershon was of the constant-supply type. For ordinary 
hard work, Mr. Habershon stated that between 3,050 and 3,660 
cubic inches (50 to 60 litres) a minute were required, and, at 
times, even 6,100 cubic inches (100 litres). If the apparatus 
were set to supply, say, 3,050 cubic indtes (50 litres), the men 
were not in a position to meet any demands for very great exer- 

• Trans. Irut. M. E., 1906, vol. xxxl., page 617. 



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DISCUSSION — USE AND CAKE OP OXYGEN-BREATHING APPARATUS. 227 

iion, in the same way that they could with a lung-governed and 
intermittent apparatus, such as the Weg- apparatus. The reducing 
Talve in the Weg apparatus was operated by the lungs, oxygen was 
supplied as required, and it was thus enabled to meet all excessive 
•demands. In the Weg apparatus, if oxygen were not required, 
it was not used ; whereas, with a constant-supply apparatus, if 
the oxygen were not required, it had to come out and it was 
wasted. If a man sat down, wearing an apparatus of the constant- 
supply type, the apparatus would only last tHe ordinary period 
of time; whereas, with the other, if the man sat down doing 
nothing, he did not use much oxygen, and he could wear his 
apparatus for a much longer time than the ordinary period for 
hard work. For instance, a man had worn an ordinary Weg 
:apparatus, sitting still, for 6 hours, and he was able to work after 
that. Thus, one or more members of a rescue-party might be 
•cut off by a fall of roof, and be unable to return to safety as early 
a« they expected: if 2 hours were required to get at a man 
after he had been using the apparatus, say, li hours, he would 
1)0 dead long before he could be reached; whereas, wearing an 
apparatus of the intermittent type, he might be able to stay 3 
•or 4 hours, with every hope of being ultimately rescued. 

With all deference to Mr. G. A. Meyer, the men who were 
going to wear the apparatus should have a great deal to say 
about the type. If one wore a nose-clip, and in addition put on 
smoke-tight goggles, and tried to do one's ordinary work in a 
pit, one would find oneself considerably crippled and uncomfort- 
able ; and he thought that the more comfortable the apparatus 
the better. Of course, the glass or mica pane in front of the 
ordinary helmet was certainly a weak point, because once that 
was broken the helmet becanu^ useless. Everything pointed to 
the use of some sort of a mouthpiece, to include the nose without 
covering the eyes, and to have the additional advantage that any 
moisture from the breath, or induced by perspiration of the lower 
part of the face, should not cloud the glass in front of the eyes. 

Mr. F. Hagemann (Hibemia Collieries, Westphalia) wrote 
that he had pleasure in acknowledging that Mr. Habershon 
judged impartially, and had brought great experience and a com- 
plete knowledge of important details to bear on the subject. 
*The decision as to whether a helmet or a mouthpiece apparatus 



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DISCUSSION — USE AND CA&E OF OXYGEN-BEEATHING APPARATUS. 

was to be preferred, was, in his opinion, not a matter for tte 
rescue-men, but one to be decided only by the engineer of the 
rescue-corps. The men would be inclined to prefer the most 
comfortable appliance ; whilst the manager of the rescue-arrange- 
ments would, if he were the right man in the right place, feel the 
full responsibility of his position, and would only think of safety : 
after this point had been satisfactorily settled, he would then 
consider the comfort of the men. Mr.^ Habershon had 
pointed out that, in Great Britain, rescue-work was performed 
voluntarily by the men ; and he appeared to be under the impres- 
sion that, in Germany and especially at the Hibemia collieries, 
it was done compulsorily. This was not the case : there was no 
compulsion throughout Westphalia ; there were up to the present 
date no Government or local rules requiring the provision of 
rescue-corps at the collieries; and none of the miners at the 
Hibernia collieries were compelled to become members of the 
rescue-corps. It had been fully recognized that such an institu- 
tion would never flourish and become effectual, unless it was 
carried out and accomplished by voluntary work. He agreed 
with Mr. Habershon that the question of helmet or mouth-breath- 
ing could be decided only after greater experience had been 
obtained, but he was not able to look at this question as one of 
detail. He was convinced that the Swiss miner, who was found 
dead in the Courriferes mine (after the German rescue-corps had 
left) with the tom-ofi helmet beside him, had not considered the 
question, when he decided to tear off his helmet. This ques- 
tion had been solved at the Shamrock colliery in two ways: 
For instance, if it was required to fit an apparatus airtight on 
the surface of the human body, it would be most easily accom- 
plished by finding the smallest surface. On the other hand, 
experience had shown that it was very difficult to fasten a helmet 
tightly on the human head, by pneumatic pressure, without affect- 
ing the circulation of the blood in the arteries of the head, and 
there was the additional danger of damage to the mica or glass 
window in the helmet. For these reasons, the arrangement of 
mouth-breathing, and closing the nostrils with greased-wadding 
plugs combined with a nose-cap, had been adopted at the 
Hibernia collieries. It was remarkable that, in the latest 
types of life-saving apparatus, the mouth-breathing method 
seemed to be preferred. Table I. records the result of 



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DISCUSSION — USE AND CARE OF OXYGEN-BEEATHING APPAEATUS. 229 



o 



5 



OQ 

X 
H 






ll 



1 
I 



aa 









1 



(I4 



I 



11 
gftC 



IS 



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S2 






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practices with the 
Shamrock appa- 
ratus at the Sham- 
rock collieries 
during 1906. The 
apparatus had 
shown some small 
defects during the 
early part of the 
year: two pract- 
ices, or 1*22 per 
cent, of a total 
of 163 practices, 
had been inter- 
rupted, owing to 
defects in the ap- 
paratus. In the 
first case, the oxy- 
gen - supply was 
exhausted in 1 
hour 45 minutes ; 
and in the second 
case, owing to a 
leakage of the 
emergency - valve, 
the oxygen - sup- 
ply was entirely 
exhausted within 
1 hour 33 minutes. 
The emergency- 
valve had only 
been applied for 
experimental pur- 
poses, and was not 
fitted to the stand- 
ard type of ap- 
paratus. The 
rescue-corps com- 
prized 31 men and 
50 trained officials. 



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280 DISCUSSION — USE AND CARE OF OXYGEN-BREATHING APPARATUS. 

a total of 81 members. Out of 67 mine-officials, 62 men, or 
92*54 per cent., had been fully trained in the care and use of 
oxygen-breathing apparatus. He (Mr. Hagemann) had had 
opportunities of seeing and experimenting with all the life- 
saving appliances at present in use, excepting the Weg, which 
had not yet been used on the Continent. 

Mr. H. E. Gregory wrote that the increasing reliability and 
usefulness of the newer forms of breathing-appliances were well 
shown in Mr. Habershon's paper ; and it was evident that the 
desiderata of purity and abundance of the breathing mixture, 
as well as simplicity of construction, were being brought to a high 
degree of safety. There was still the possibility of defect in 
these matters, and whether this possibility had been sufficiently 
recognized and provided for was, to some, still a matter of doubt. 
Mr. Habershon did not say whether his appliances could be 
considered simple in construction, or whether any difficulty 
might be overcome by perfect training of the wearers and by 
rigorous care and inspection of the apparatus. The training 
would be of greater value if the practising chambers for the 
apparatus were filled with a de-oxidized atmosphere, such as a 
cooled beehive coke-oven effluent, or boiler-flue gases. Men 
who had been trained under such conditions would be more 
confident, and therefore more successful, when they came to 
practical work in a wrecked mine. The probability of a fatal 
sequel to a breakdown or defect in the apparatus, when in use, 
should be provided for. The provision of each apparatus in 
duplicate would make the appliances too heavy for a man to 
carry, but perhaps the more delicate parts might be duplicated 
and thereby increase the safety. With regard to the point 
raised by Mr. Habershon as to the comparative advantages or 
disadvantages of the helmet and mouth-breathing types, his (Mr. 
Gregory's) preference for mouth-breathing was further strength- 
ened by the following quotation : — " Breathing air containing 
4 to 10 per cent, of carbon dioxide brings on pains and throbbing 
in the head, accompanied by vomiting."* Vomiting, when 
wearing a helmet, would, by choking up the tubes and valves, 
probably prove fatal ; whereas the wearer of a mouth-breathing 

• Trans, Inst. M, E,, 1907, vol. xxxiii., page 214; and "The Physiological 
Eflfects of Air vitiated by Respiration," by Dr. J. S. Haldane and Mr. J. Lorrain 
Smith, Tht Journal of Pathology and Bacteriology ^ 1892, vol. L, page 168. 



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DISCUSSION USE AND CAKE OP OXYGEN-BHEATHING APPARATUS. 281 

apparatus would possibly be able to remove the mouthpiece 
before vomiting began, and to re-insert it immediately after- 
wards, and thus preserve the apparatus from injury. The mem- 
bers and the mining community generally were undoubtedly 
under a great obligation to Mr. Habershon and the associated 
•colliery companies for their great and humane work directed to- 
wards minimizing the penalties of accidents in mines; and the 
results of their practical efforts and achievements, as shown in 
"this and previous papei*s, were of the greatest importance and 
would be a useful guide in the establishment and working of 
other rescue-stations. 

Mr. Richard Jacobson (London) wrote that Mr. Habershon 
iad referred to the grave danger likely to occur when using a 
Jiydraulic pump to obtain a pressure of 120 atmospheres in a small 
oxygen-cylinder: namely, the possibility of rust entering the 
oylinder and passing into the vital parts of the apparatus, with 
the ultimate result of hindering the free circulation of air in the 
breathing-apparatus. In order to avoid the possibility of that 
danger, Messrs. Draeger had constructed *a high-pressure pump, 
which worked without the use of water. An interesting paper 
on " Tests of Life-saving Apparatus," in which a self-acting 
work-recording machine was used and accurate determinations 
of carbon dioxide made with a special apparatus, had recently 
been published.* He could not agree with Mr. Hagemann that 
the decision as to whether a man should wear a helmet or mouth- 
breathing bag should rest with the instructor or engineer in 
charge of a rescue-party. That might be the case in practice- 
work, but in the case of actual rescue-work, where a man wanted 
all his confidence for the task before him, it was certainly 
inadvisable to force him to wear an apparatus in which he had no 
•confidence and which made him uncomfortable and nervous. 
With apparatus in which the helmet and mouth-breathing appar- 
atus wei-e equally efficient, as was the case with the Uraeger 
apparatus, a man certainly ought to be allowed to choose for 
himself. With regard to Mr. Hagemann's reference to the 
danger that attended the use of a mica-window in the helmet, he 

• **Die Priifung von Rettungsapparaten durch selbsttatiffe Arbeitsmeseung 
find exakte Kohienaaure-Bestimmung, von Heinrich nnd Bernnard Draeger," by 
Vn, Th. Wetzke, Chrifltern and Wex, Kohle und Erz, 1907, No. 6. 

VOI^ XZXIII.~190<-1S07. IS 



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282 DISCUSSION USE AND CARE OF OXYGEN-BEEATHING APPARATUS* 

(Mr. Jacobsou) would point out that the window in the Draeger 
apparatus was protected against damage by a strong wire guard. 
The pneumatic arrangement in the Draeger helmet for making 
an airtight joint between the helmet and the face of the wearer 
was the only possible successful method. Referring to Mr. 
Hagemann's remarks on the Swiss miner who, at Courrieres, was 
found dead, with his helmet torn off, he (Mr. Jacobson) might 
state that it had been established beyond a doubt that the man's 
apparatus was not in action, and that two other men who were 
with him, wearing the Shamrock apparatus, were affected by 
the gas, but had had time to withdraw to a place of safety. Mr. 
H. E. Gregory's remarks about the advantage of mouth-breathing 
types of apparatus showed a want of acquaintance with the 
Draeger helmet. The pneumatic method of making an airtight 
joint in no way hindered the circulation of the blood ; the valves 
were arranged so that they could not be choked; and, in case 
of need, the air-lid in the helmet could just as easily be opened 
by the wearer, as the mouthpiece could be removed. 

Mr. M. H. Habershon, replying to the discussion, thought 
that Mr. Gregory, in speaking of the breathing of carbon dioxide 
was referring to the ShamrockrOiersberg type of apparatus, and 
probably had had no experience of recent appliances fitted with 
improved regenerators. His paper contained no reference to the 
Weg apparatus, which was not yet standardized, and he had had 
no opportunity of testing it. He had recently seen the improved 
Shamrock apparatus, which showed a decided advance on the 
type used at the Tankersley rescue-station, and he thought it was 
probable that it would now permit of similar hard work being 
done to that which they had accomplished with the Draeger 
appliance. Experiments had not been made with the pneumato- 
gen, on account of the high cost of the cartridges used with that 
apparatus: their funds were limited, and they were obliged to 
proceed carefully. During the last few years, however, various- 
appliances had been tested as they had become available, and a 
number of men had been trained. At the present time, about 
68 men, altogether, had been trained, connected with the four 
colliery companies interested in the rescue-station. The earlier 
appliances were, however, now entirely obsolete, and their rescue- 
station was not adequately equipped with a sufficient number o£ 



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DISCUSSION — ^USE AND CAKE OF OXYGEN-BREATHING APPARATUS. 283 

up-to-date and reliabk apparatus. Sergeant Winbom's remarks 
as to the probable value of the lighter form of the pneumatogen 
seemed veiy apropos to the opinion expressed by Mr. F. A. Gray, 
H.M. inspector of mines, in his evidence before the Boyal Com- 
mission on the question of the possibility of saving the lives of 
men.* The first type of pneumatogen had a total weight of only 
3J pounds, and would supply air for 46 minutes. It could be 
easily carried by a rescue-party, and used in the work of bringing 
men out through an irrespirable atmosphere.t 

Referring to the report on the demonstration of the use of 
rescue-apparatus at Altofts colliery, he thought that the dis- 
tances walked, namely, 1,760 yards with the Weg and 384 
yards with the Draeger, were somewhat misleading, as the men 
wearing the Draeger apparatus only walked the distance 
arranged by the programme, not knowing that any further 
distance would be recorded. 

The best duration-tests made at the Tankersley rescue-station 
were as follows: — (1) W. Clifford, of Strafford colliery, with 
Draeger mouth-breathing type, 4 hours 3 minutes; no work 
done. (2) J. Anderson, of Barrow collieries, with Draeger mouth- 
breathing type, 5 hours, during which time he walked 7,400 
yards. At the conclusion of this test the man was very hungry : 
this seemed the most noticeable fact, after wearing the apparatus 
for a long period. (3) As regards weight-lifting tests: J. 
Anderson, on one occasion, had raised a 56 pounds weight to a 
height of 7 feet, 610 times, equal to 239,120 foot-pounds, in 1 
hour and 40 minutes. At Altofts collieries, he and another 
man performed together 256,032 foot-pounds ; but, as Mr. Lloyd 
had pointed out, they had previously been over falls, and assisted 
in bringing out the dummy man on a sledge. He thought that the 
fact that it was thus possible to do extremely hard work for 2 
hours with this apparatus, somewhat answered Mr. Lloyd's re- 
marks about the disadvantage of using an apparatus with a 
constant supply of oxygen; and that much could be said in 
favour of the constant supply, which required no thought, or 
manipulation, or attention whatever, from the wearer for 2 hours, 

• Minutes of Evidence taken before the Royal Commission on Mines, 
Wednesday, 28th November, 1906, proof; and The Colliery Otuirdian, 1907, 
vol. xciii., page 395. 

t Trans. Inst, M. E., 1906, vol. xxxii., page 55. 



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284 DISCUSSION USE AND CAEE OF OXYGEN-BEEATHING APPAHATUS. 

and thus added to the desired simplicity of construction. He 
thought that an apparatus sufficient for the above work for 2 
hours might be considered a serviceable apparatus, and that, with 
the improvements which were constantly being introduced, there 
was every encouragement to go foiward. He thanked the 
members for the kin'lly manner in which they had received 
his paper. 



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TRANSACTIONS. 235 



THE MINING INSTITUTE OF SCOTLAND. 



EXCURSION MEETING, 

POLMAISE COUJERISS, JuNK 29tH, 1907. 



The members, numbering about 160, were driven from 
Stirling to the Polmaise collieries of Messrs. Archibald Eussell, 
Limited, where they were met by Mr. James Salmond, general 
manager, and Mr. David Todd, local manager, and shown over 
the works. Luncheon was kindly provided at Stirling. 



The President (Dr. Robert Thomas Moore) moved that the 
thanks of the Institute be heartily given to their entertainers and 
their officials. 



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236 TRANSACTIONS. 



THE MINING INSTITUTE OF SCOTLAND. 



GENERAL MEETINO, 
Held in Stiblino, June 29th, 1907. 



Db. ROBERT THOMAS MOORE, Pbbsidbnt, in thx Chaib. 



The following gentlemen were elected: — 

Mbmbkbs— 
Mr. J. A. G. Bayne, Kerse Road, Grangemouth. 
Mr. RoBEBT H. Cbawfobd, 208, St. Vincent Street, Glasgow. 
Mr. James Dalglbish, Woodbank, Park Street, Wiabaw. 
Mr. William Davidson, Plean Colliery, Plean. 
Mr. John Gibson, Earlston, Kilmarnock. 
Mr. John Gbay, GU>rdon Cottage, Cowdenbeath. 
Mr. Alexandeb Hamilton, Roman Camp, UphalL 
Mr. James Hbndebson, Auchengeich, Chryaton. 
Mr. Peteb Henderson, Lochgelly Collieries, Lochgelly. 
Mr. William King, 7, Dalkeith Avenue, Dumbreok, Glasgow. 
Mr. Jambs Leckie, Bertrohill, Shettleston. 
Mr. George A. Lindsat, 5, Leslie Road, PoUokshields, Glasgow. 
Mr. H. A. McGuFFiE, 87, Union Street, Glasgow. 
Mr. Angus Mackay, Jamadoba Colliery, Gharia P.O., Bengal, India. 
Mr. Pebcy H. M. Mackintosh, Public Works Department, Greymonth, 

New Zealand. 
Mr. Thomas Malone, Buen Retire, Coronel, Chile. 
Mr. James Pabk, Viletta, Woodbine Avenue, Airdrie. 
Mr. Thomas Reid, P.O. Box 24, Bethlehem, Orange River Colony. 
Mr. David Speib, Balgonie Colliery, Thornton. 

Associate— 
Mr. RoBEBT Leogatt, Clover Park, Dunaskin, Ayr. 



The following description of ** Polmaise Collieries " by Mr. 
James Salmond was held as read : — 



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POLMAISE COLLIERIES. 237 



POLMAISE COLLIERIES. 



By JAMES SALMOND. 



Polmaise collieries, the property of Messrs. Archibald Bussell, 
Limited, consist, at present, of four shafts, situated in the parish of 
St. Ninians : Jfos. 1 and 2 pits being about IJ miles, and Nos. 3 
and 4 pits 3 miles, distant south-east from the county-town of 
Stirling. The mineral-fields comprize the following leaseholds : — 
Polmaise, 2,100 acres ; Townlands, 600 acres ; Blackgrange and 
Westga-ange, 400 acres; Stewarthall, 270 acres; Broadleys, 125 
acres; and Clayslaps, 30 acres; a total area of 3,525 acres. 
Numerous bores, put down at former times on the Townlandfl 
and Stewarthall, along with seven diamond bores put down by 
th© present tenants on Polmaise, Blackgrange and Westgrange, 
go to prove the existence of the various seams of coal under 
practically the whole of the field. The strata, which are in 
the Carboniferous Limestone series, have an inclination of 1 in 
4J towards the north-east. 

Nos. 1 AND 2 Pits. 

The sinking of Noe. 1 and 2 pits, 66 feet apart, was com- 
menced in December, 1902, and finished in June, 1904. The 
No. 1 shaft, 18 feet long and 6^ feet wide, contains two winding 
spaces of 7 feet, and one space of 1 foot and one of 2 feet are 
utilized for water-pipes ; and the No. 2 or upcast shaft, 19^ feet 
long and 6^ feet wide, contains two winding spaces of 7 feet, one 
space of 3^ feet, and another of 1 foot in which are thie cables. 
The surface (Table L), which was soft and troublesome, was 

^Table I.>— Surfagb-stbata Sunk through in Nos. 1 and 2 Pits, 
Polmaise Collikbies. 



Thick- Depth 

neaa of from 

yo. Deacription of strata. Strata. Surface. 

Ft. Ina. Ft Ina. 

1 BoU 16 16 

2 Yellow clay 3 6 5 

3 Blue silt, very soft ... 21 26 

4 Peat 6 26 6 _ , „ 

6 Fine sand, with boulders 19 99 



Thick- Depth 

neas of from 

No. Description of Strata. Strata. Surface- 

Ft. Ina. Ft. Inn. 

6 Coarse sand and shells 6 39 

7 Ked clay and stones... 4 6 43 U 

8 Red clay, very soft ... 36 6 80 

9 Scknd, gravel and 



water 12 38 6 1 10 Broken rock 2 6 101 6 



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238 



POLMAISE COLLIERIES. 




I 



s 

5 



O 

M 



sunk through by 
means of a steel 
crib 24J feet long,. 
9^ feet wide and 
7 feet deep. 

The water got 
during the sinking 
was brackish, and 
was observed to be 
most abundant in 
quantity at the 
time of high tide 
in the river Forth^ 
which is about 1 
mile distant. When 
sunk through the 
surface, No. 1 pit 
was lined with 
pitchpine, 9 inches 
wide and 6 inches 
thick; and all the 
other pits were 
lined with pitch- 
pine 9 inches 
square. A second 
set of barring, 9 
inches wide and 4 
inches thick, was 
then built in to 
the finished size of 
the pit, the space 
between the two 
barrings being fil- 
led with clay. The 
remainder of the 
shafts is lined 
throughout with 
pitchpine, 9 inches 
wide and 3 inches 
thick: thebuntons. 



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POLMAISE COLLIERIES. 28^ 

9 inches wide and 4 inches thick, being placed 4 feet apart. The 
wall-plates are 24 feet long, 9 inches wide and 3 inches thick, and 
the corner-rackings, 3 inches square. The slides are pitchpine,. 
5 inches wide and 4 inches thick. 

Seam^ of Coal. — Twelve seams of coal were passed through 
in the shafts, amounting in thickness to 23 feet 3 inches. The 
thicknesses of the seams which are at present being worked, and 
the depths at Jfo. 1 pit, are as follows : — The Hartley seam, 2 feet 
at 291 feet; the Greenyard seam, 3 feet 3 inches at 372 feet; 
the Main seam, 3 feet 1 inch at 447 feet; and the Knott seam» 
3 feet at 486 feet. The whole of these seams are wrought by 
the longwall system. 

The first two seams are navigation coals and the others anthra- 
cite, with the following analyses: — {a) Navigation coal, volatile 
matter, gas, tar, etc., 24*41 per cent. ; sulphur, 0*16 per cent. ; 
and water, 3*62 per cent. : a total of 28*19 per cent; coke, fixed 
carbon, 68'86 per cent. ; sulphur, 0*41 per cent. ; and ash, 2*55 
per cent. : a total of 71*81 per cent. The specific gravity is 
1*33. The practical heating power, by Playfair's formula (water 
at 212 degrees Fahr. evaporated by 1 pound of coal), is 9*60 
pounds. (6) Anthracite coal, volatile matter, gas, tar, etc., 1011 
per cent. ; sulphur, 0*09 per cent. ; and water, 2*00 per cent. : a 
total of 1220 per cent. ; coke, fixed carbon, 83*69 per cent. ; 
sulphur, 0*61 per cent. ; and ash, 3*50 per cent. : a total of 
87*80 per cent. The specific gravity is 1*30. The practical 
heating power by Playfair's formula (water at 212 degrees Fahr. 
evaporated by 1 pound of coal) is 11*18 pounds. 

Boilers. — Steam is supplied by six Lancashire boilers, 30 feet 
long and 8 feet in diameter, working at a pressure of 100 pounds 
per square inch. The chimney is 125 feet high, 12 J feet square 
at the base and 7i feet square outside at the top. For the 
purpose of dealing with the anthracite gum and table-pickings, 
forced-draught has been fitted to the boilers. A Sirocco fan, 
36 inches in diameter, produces the draught, which is led 
through pipes into perforated hollow fire-plates. The motor 
for driving the fan, of 20 horsepower, of the squirrel-cage 
type, runs at 940 revolutions per minute, and is started by 
means of an oil-immersed auto-starter. Owing to the pit- water 



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240 POLMAISE COLLIERIES. 

being unsuitable for the boilers, a turbine pump, situated at 
the Bannock burn, pumps a supply of water to Nos. 1, 2, 3 and 
4 pits. This pump is capable of delivering 150 gallons per 
minute, and is driven direct by a squirrel-cage motor of 8i 
horsepower, running at 1,450 revolutions per minute. The 
exhaust steam is led to a heating cylinder in connection with 
two feed-pumps, and heats the water before it is fed into the 
boilers. 

Winding^engines, — The winding-engines are alike at both 
pits, each having* two horizontal cylinders, 22 inches in diameter 
and 4i feet stroke, fitted with balanced slide-valves, and drums 
12 feet in diameter. The engine-houses are built of brick and 
are of ample size, with open bound roofs, and lined with red 
pine. The pithead frames are of the trestle type, constructed of 
pitchpine and oak, and the pulleys are 12 feet in diameter. 
The winding-rope is 3i inches in circumference, and the cage 
is constructed to carry two hutches with a capacity of 10 cwts. 
each. The hutches have steel sides and bottoms, with wooden 
ends, and the rails are of the bridge type. 

Electric Generating Plant, — Two compound steam turbines, 
each of about 350 horsepower, and running at 3,000 revolutions 
per minute, are coupled direct by means of flexible clutch-coup- 
lings to three-phase, 50 periods, 500 volts alternators of 200 
kilowatts output. The direct-driven exciters are mounted on 
an extension of the armature-spindle. The shaft at the other 
end bearing carries a screw-thread, working a worm-wheel 
which actuates a pump for forcing oil through the bearings and 
the steam-admission governor by means of an eccentric. A 
pump, situated in the boiler-feed house, circulates water round 
the oil-tanks to keep them cool. The machines are at present 
non-condensing, but the question of condensing is under 
consideration. 

Switchboard and Switchgear. — The main switchboard in the 
power-house consists of five white Sicilian-marble panels: — Two 
panels for controlling the two generators are so arranged that the 
machines can be run in parallel, and each having mounted 
thereon, three ammeters ; an exciter voltmeter ; a three- 
pole oil-switch and fuses; a pilot switch; a synchroniz- 



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POLMAISE COLLIERIES. 241 

ing arrangement; and an earth-detecting device mounted on a 
swinging bracket at the end of the board. Two feeder-panels, 
each having mounted thereon two ammeters; and two oil- 
immersed switches with fuses. One lighting panel, having 
mounted thereon three transformers, each having a capacity 
of 7i kilowatts for reducing the current to 100 volts continuous 
current for the purposes of lighting ; three ammeters ; and three 
back-of-panel type switches on the high-tension side of the 
transformers. 

The underground switchgear is of the totally-enclosed unit 
type. In the Greenyard seam there are two pillars, and in the 
Knott seam three pillars, each containing an ammeter, an oil- 
break switch, fuses, isolating links, omnibus-bar ch^unbers, tri- 
fucating box, etc. On pillars which control the haulages, the 
oil-break switch is replaced by oil-break circuit-breakers. 

Ventilation, — The fan is driven direct, by a non-condensing 
compound steam-turbine similar to those driving the alternators. 
Two single-inlet fans of the propeller type, 47 inches in dia- 
meter, when running at 2,500 revolutions per minute, are 
capable of exhausting 150,000 cubic feet of air per minute 
against a watergauge of 3 inches. 

Safety-lamps. — Safety-lamps are in use throughout these pits, 
they are magnetically locked and electrically ignited : the under- 
ground appliance for relighting them being so constructed that 
it cannot be operated nor can a spark be produced unless the 
lamp is in position underneath an airtight closed-down lid. 
Two machines are fitted in the lamp-cabin : one for charging the 
accumulators, and the other for cleaning 100 lamps per hour, 
each being driven by a motor of IJ horsepower. 

Haulage, — ^The only dip workings at present are in the Hartley 
seam, and the coal is taken out therefrom by means of a main-rope 
haulage driven by an enclosed slip-ring motor of 85 horse- 
power running at 560 revolutions per minute, and operated by a 
single-hand drum-type oil-immersed controller with oil-immersed 
resistances suitable for starting against a 200 per cent, full-load 
torque in 30 seconds, and regulating down to half-speed for one 
minute in each six. 



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242 POLMAISE COLLIERIES. 

Pumping. — The AVorthingion six-stage turbine pump, placed 
in the Knott coal-seam, is capable of pumping 200 gallons of 
water per minute to the surface, and is driven direct by a 
motor running at 1,440 revolutions per minute. The motor 
is mounted on a combination base-plate, and is operated by mean* 
of an oil-immersed auto-starter. 

Another pump, in the Hartley dook, delivers into the lodg- 
ment of the turbine pump. This three-throw pump, having 
rams b\ inches in diameter and 9 inches stroke, is driven 
thi-ough gearing by a squirrel-cage motor of 9 horsepower, run- 
ning at 940 revolutions per minute, .and operated by an oil- 
immersed auto-starter. 

Screening and Washing Plants, — The screening and washing 
plants, together with the housing and gangways, are arranged 
for dealing with 1,000 tons, but have been found capable of 
dealing with 1,200 tons in a day of 9i hours. The screening 
and washing plant-houses are of brick and steel, and the pithead 
house and gangways are of steel: the whole is roofed over 
and covered in with corrugated-iron sheeting and glass, no part 
of the plant or gangways being exposed to the weather. The 
loaded hutches run by self-acting gradients from the pit-mouth 
to the bottom of a creeper-haulage, which elevates them to a 
sufficient height to carry them over the weighing-machine to 
the revolving tippers fitted with automatic starting-and-stopping 
gear. From the tippers, the tubs gravitate around the 
cleaning plant to another creeper which elevates them 
to a height sufficient to enable them to gravitate to the 
back of the pits. Fixed screens are provided in the 
pithead-house, for dealing with coal for local sales. The 
navigation coal is passed over two picking-belts of the bar- 
grating type : the delivery-ends being provided with radial por- 
tions, operated by means of power-driven worm-gear for lowering 
them into the trucks to minimize the breaking when loading. 
The small coal from the shakers and the belts is collected by 
means of a scraper-conveyor, and is delivered into wagons for 
conveyance to the washer at Nos. 3 and 4 pits. 

The anthracite-coal plant consists of two sets, one of which 
is used for round coal when required, and is similar to those 
already described. The other set is also similar, but contains 



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POLMAISE COLLIERIES. 248 

two sets of crusher-rolls which are employed for reducing* the 
round coal to the size of jumbos and trebles, the latter of which 
are passed over a picking-belt of the same kind as the others. 
The jumbos are delivered to a small conveyor, which in turn 
delivers them to the round-coal belt. The coal that is smaller in 
«ize than the trebles passes into a scraper-conveyor, and is con- 
veyed to the dross-pit of the washer. The refuse, picked off the 
picking belts, is thrown into a conveyor, running at right angles 
under the picki^ig-floor, and conveyed to a hopper at the pithead, 
whence it is taken to the dirt-bing in hutches. 

The anthracite-washing plant, with a capacity of 30 tons per 
hour, is arranged to separate the small coal into doubles, 
singles, pearls and gum. The small coal, elevated by means 
of a bucket-elevator from the dross-pit, is delivered into a rotary 
screen, where it is separated into four sizes, the pearls and gum 
being delivered into a nest of six felspar-washers, the singles 
into two bash-tanks, and the doubles to the Primus washer. The 
fine coal and water is led by pipes to a silt-recoverer, which 
recovers the fine coal and delivers it into a conveyor supplying 
the boiler stokehold. The refuse, taken out of the coal by wash- 
ing, is elevated by means of bucket-elevators and delivered 
into the same hopper as that which receives the refuse from the 
screening plant. 

The washing and screening plants are each driven by means 
of a slip-ring motor of 100 horsepower, running at 470 revolutions 
per minute, and operated by a faceplate starter. The silt-i'eoovery 
plant is driven by a squirrel-cage motor of 10 horsepower, run- 
ning at 940 revolutions per minute, and started by means of an 
oil-immersed auto-starter. 

Primus Washer, — A Primus washer has been fitted up, on 
trial, to separate from the doubles a sclit* which closely approxi- 
mates the weight of coal. Its capacity is about 15 tons per hour, 
and in principle it differs from other washers in use, the un- 
cleaned coal being fed into a perforated-bottom reciprocating 
box, in motion in water, causing the coal to be displaced by the 
sclit which forms the bottom. The depth of bottom and the 
line of separation are under positive control, and subject to 
delicate adjustment by levers. Once adjusted, the separation is 

* Slaty coal. 



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244 FOLMAISE COLLIEBIES. 

automatic, the products passing to the draining elevators and 
thence to the wagons. The plant is driven by a small horizontal 
steam-engine, with a cylinder 7 inches in diameter and 8 inches 
stroke. 

Railways, — In addition to the locomotive-road, there are 
eight other roads, for dealing with the different classes of fuel, 
laid at an inclination of 1 in 75. 

Offices and Workshops, — The offices and workshops, of ample 
size, comprize the counting-house, store, ambulance-room, 
smithy, and engineer's and joiner's shops. 

Dwelling-houses. — Thirty cottages, with all modern conveni- 
ences, are erected at the entrance to the colliery, principally for 
the use of officials. 

Nos. 3 AND 4 Pits. 

Nos. 3 and 4 pits lie about If miles to the east of Nos. 1 and 2 
pits, and are connected thereto by a private railway 2^ miles in 
length. The sinking was commenced in August, 1904. No. 3 
pit was finished in. December, 1905, and No. 4 pit in April, 1906. 
The shaits passed through twenty seams of ooal, over 1 foot 
in thickness, the total amounting to 32 feet 6 inches. The seams 
at present being worked, and the depths at No. 3 pit, are as 
follows : — The Hirst seam, 2 feet 2 inches at 102 feet; the Hart- 
ley seam, 2 feet 4 inches at 1,008 feet; and the Knott seam, 
2 feet 6 inches at 1,242 feet. The Index limestone, 33 inches 
thick, was got at 786 feet. 

The surface was of the same soft nature, although not so deep 
as that at Nos. 1 and 2 pits, being in this case 60 feet thick. The 
same method of sinking was adopted, a crib of like dimensions 
being used : but a second set of barring was not put into No. 4 
pit, as it had been decided to have separate winding-spaces for 
the Hirst coal-seam. The No. 3 and downcast pit, 22 feet long 
and 6i feet wide, has four divisions, two of them for winding 
purposes being 7 feet, another of 6 feet, and the fourth, 1 foot, is 
used for the cables. The No. 4 pit, 16 feet long and 6^ feet wide, 
has three divisions, two of them, each 7 feet, being used for wind- 



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POLMAISE COLLIERIES. 



245 



ing, and tie other, 

1 foot, contains the 
steam- and water- 
pipes. Down to the 
Hirst coal - seam, 
the pit is 22| feet 
long and 8 feet 
wide, owing to 
there being two 
separate winding 
spaces of 3 feet 
10 inches by 6 feet 
to this seam, over 
and above those 
already mentioned. 
Both pits are lined 
throughout, and 
are fitted with the 
same sizes of wood 
as in Nos. 1 and 

2 pits. 

Bailers, — There 
are six Lancashire 
boilers, 30 feet long 
and 8 feet in dia- 
meter, fitted with 
rocking firebars 
and working at a 
pressure of 100 
pounds per square 
inch. The chim- 
ney is of the same 
dimensions as that 
at Nos. 1 and 2 
pits, and the ex- 
haust steam is also 
passed through a 
heater, there being 
two feed-pumps. 




H 

3 

O 

H 



o 



i 

2 



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246 POLMAISE COLLIERIES. 

Winding-enghies. — There are three winding-engines, two 
winding from each of the pits and the other from the end of 
No. 4 pit. The former of these are both alike, each having 
two horizontal cylinders 26 inches in diameter by 5 feet stroke, 
iitted with balanced valve-gear, and drums 16 feet in diameter. 
The winding-engine to the Hirst coal-seam is of the same type, 
with cylinders 12 inches in diameter and 2i feet stroke, the 
-drums being 5 feet in diameter. The pithead frames are of 
the same style as at Nos. 1 and 2 pits, with pulleys 16 feet and 
S feet in diameter respectively for the large and small pits ; the 
ropes are 3^ inches in circumference. 

Electric Generating Plant. — The generating plant at present 
consists of an alternator with a fixed armature and revolving 
field magnets, and a direct-coupled exciter. It is designed to 
give an output of 200 kilowatts at a pressure of 500 volts, 50 
periods, three-phase, when running at the speed of the engine, 
namely, i28 revolutions per minute. The engine of 300 brake- 
horsepower is of the compound, double-crank, enclosed and 
iorced-lubrication type, the cylinders being 16^ and 24J inches 
in diameter and lOJ inches stroke. Provision has been made for 
accommodating another generator in the same house. 

Switchgear. — The switchboard consists of a generator panel, 
«. lighting panel and a feeder panel fitted generally in the same 
manner as at J^os. 1 and 2 pits. In the Hirst seam, there are 
:five feeder and control pillars, and in the Hartley seam two, all 
of the same unit type as those in use at Nos. 1 and 2 pits. 

Ventilation. — The ventilation is produced by a Capell fan, 
•8 feet in diameter and 7 feet in width, running at 320 revolutions 
per minute and capable of exhausting 150,000 cubic feet of air 
per minute at a watergauge of 3 inches. It is rope-driven by 
:a single horizontal engine, with a cylinder 18 inches in diameter 
and 2 feet 10 inches stroke, fitted with Meyer expansion-gear, 
and running at 80 revolutions per minute. 

Safety-lamps. — ^With the exception of the Hirst seam, safety- 
lamps are used throughout. In this case, the cleaning and 
-charging machines are driven by two steam-engines, with 
cylinders 5 inches in diameter and 6 inches stroke. 



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POLBiAISE COLLIERIES. 247 

Haulage. — There are two main-rope haulages: that ia the 
Hirst seam is driven by a slip-ring motor of 85 horsepo»wer, run- 
ning at 560 revolutions per minute; and the other in the 
Hartley seam is driven by a motor of 100 horsepower of the 
same type, but running at 470 revolutions per minute. Both 
of the motors are governed by a controller similar to that in 
No. 2 pit. 

Primping. — In the Hirst seam, there is a three-throw pump 
and motor of the same dimensions as that in No. 2 pit forcing 
water to the surface. Another pump, placed in the Knott coal- 
seam, forces its water to a lodgment at a depth of 810 feet. It 
is a three-throw pump, having rams 4 inches in diameter and 
9 inches stroke, and is belt-driven by a squirrel-cage motor of 
15 horsepower running at 710 revolutions per minute, and oper- 
ated by means of an oil-immersed auto-starter. The water in 
the lodgment at 810 feet is dealt with by a Worthington pump, 
having two steam-cylinders 20 inches in diameter, and two 
double-acting water-plungers 7 inches in diameter, all having a 
stroke of 15 inches. 

Screening and Washing Plants. — The screening plant is on 
similar lines to that at Nos. 1 and 2 pits, the gangways in this 
case being open, only the pitheads being covered. There are 
three picking-belts each being used respectively for Hirst (or 
splint) coal, anthracite coal and best house coal. The small coal 
from the anthracite table is delivered into wagons, and taken to 
the washer at Nos. 1 and 2 pite. The dross from the other 
tables is treated by a washer on the ground. The whole of the 
cleaning plant is driven by a horizontal steam-engine, with two 
cylinders 8 inches in diameter and 16 inches stroke. 

The washer is of the same kind as that at Nos. 1 and 2 pits, 
but it is able to wash 50 tons per hour, having three bash-tanks 
for treating the trebles, doubles and singles, and two nests of six 
felspar washers for treating the pearls and gum. The plant is 
driven by a horizontal engine, with two cylinders 10 inches in 
diameter and 18 inches stroke. The silt-recoverer, and the 
conveyor for the gum received from it and conveyed to the 
boilers, is driven by an engine with a cylinder 6 inches in 
diameter and 12 inches stroke. 



TOL. XXXni.-1906-lMf7. 



19 



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Hs 



POLMAISE COLLIERIES. 



Railwai/'sidimjs. — There are eip^ht roads in addition to the 
engiue-road, for dealing with the various classes of fuel. 

Dwelling-houses. — There are twenty cottages for officials 
erected at the entrance to the colliery ; eighty workmen's houses 
of the room-and-kitchen type, with all conveniences, have been 
built near the colliery; and a hundred more are in course of 
erection. Water for domestic purposes is led in pipes for a 
distance of 2 miles from the town-mains: and, owing to the 
supply being scarce, storage-tanks have been erected. The pit- 
water, pumped into tanks, is conveyed to the houses for flushing 
purposes. 



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TKANSACTIONS. 249 



THE NORTH OF ENGLAND INSTITUTE OF MINING 
AND MECHANICAL ENGINEERS. 



GENERAL MEETING, 

HiLD IN THE Wood Mbmobial Hall, Newoastle-upon-Ttnk, 

June 8th, 1907. 



Mb. J. H. MERIVALE, President, in the Chair. 



The Secretary read tie minutes of the last General Meeting 
and reported the proceedings of the Council at their meetings 
on May 25th and that day. 



The Secretary read the balloting list for the election of 
officers for the year 190T-1908. 



The following gentlemen were elected, having been previously 
nominated: — 

Members — 
Mr. John Abel Chapman, Engineer, 56, Bewick Road, Gateahead-upon-Tyne. 
Mr. Francis Henrt Lambton Crovdace, Colliery Manager, The Lodge, 

Lambton, Newcastle, New South Wales, Australia. 
Mr. Sydney Croudace, Colliery Manager and Mining Engineer, New 

Lambton, Newcastle, New South Wales, Australia. 
Mr. Robert William Hall, Colliery Manager, Thrislington Colliery, West 

Comforth, S.O., County Durham. . 
Mr. Harold Horwood-Barrett, Mining and Consulting Engineer, 2, Park 

View Villas, Hove, Brighton. 
Mr. Charles Howson, Colliery Manager, Harraton Colliery, Chester- le-Street. 
Mr. DtTDLEY James Inskipp, Mining Engineer, Grand Hotel, Bulawayo, 

Rhodesia, South Africa. 
Mr. William Henry Ramsay, Colliery Manager, Harperley Hall, Tantobie, 

S.O., County Durham. 
Mr. Robert Smart, Assayer to the Yukon Government, White Horse, Yukon 

Territory, Canada. 

VOL. xxznL-t0O<-in7. 20 



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260 DISCUSSION — ^THE PNEUMATOGEN. 

Mr. William Tbutbnbebo, Mining Engineer and Surveyor, Nenthead^ 

Alston, S.O., Cumberland. 
Mr. Errington Thompson, Metal-mlne Manager, Weardale House, St. John'a 

Chapel, S.O., County Durham. 
Mr. HiNRY Walker, H.M. Inspector of Mines, Durham. 
Mr. HxKRT STKvsNSOir Willis, Colliery Manager, The Garth, Medomsley,. 

S.O., County Durham. 
Mr. William Wilson, Colliery Manager, Chilton Colliery, via Ferry Hill. 

AssociATB Members — 
Mr. Featherstone Fenwiok, County Chambers, Newcastle-upon-Tyne. 
Mr. James Kirklet, Cleadou Park, Cleadon, Sunderland. 

Associates— 
Mr. Philip Sidney Blundek, Under-manager, The Villas, Dean Bank,. 

Ferry Hill Village, Ferry Hill. 
Mr. George Elliott, Under-manager, Dinnington Colliery, Dudley, S.O.^ 

Northumberland. 
Mr. George Tweddell, Back-overman, 61, Double Row, Seaton Delaval, S.O.,. 

Northumberland. 

Students— 
Mr. William Ernest Avery, Mining Student, Ravensworth Colliery Office^ 

Low Fell, Gateshead-upon-Tyne. 
Mr. John Brown, Mining Student, 4, Scotch Street, Whitehaven. 
Mr. Thomas Watson, Jud., Mining Student, Rosebank, Darlington. 
Mr. Hubert Watts, Mechanical Engineering Student, Cleveland House,. 

North Shields. 



DISCUSSION OF MR. R. CRBMER'S PAPER OX ** THE 
PNEUMATOGEN : THE SELF-GENERATIXG RESCUE. 
APPARATUS, COMPARED WITH OTHER TYPES."* 

Mr. M. Walton Browx said that Mr. Fickler, of Gneisenau 
colliery, Westphalia, had stated that on April 17th, 1907, ia 
company with Mr. von Harlessen and Mr. Qiese, he had made 
a trial with the pneumatogen in the mine.t After the appli- 
ance had been in use for about 18 minutes, and as they were 
walking up a steep incline, it commenced to burn, and after 
great trouble he was able to prevent the flame from burning 
his clothes. It was found afterwards that heated peroxide of 
sodium and potassium had come into contact with an indiarubber 
ring, and caused it to take fire. 

• Trans. Inst, M, E., 1906, vol. xxxii., page 61. 
t QlUckauf, 1907, vol. xliii., page 524. 



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DISCUSSION — SINKING BY THE FEEEZING-PROCESS. 261 

Mr. L. H. Hodgson said that the pneumatogen had been tried 
by Mr. W. E. Garforth in the Altofts-coUiery experimental gal- 
lery with good results, but he thought that appliances of this 
kind would only be generally adopted in Great Britain when they 
were enforced by law. 

Mr. R. Cremer (Leeds) wrote that Mr. von Harlessen, who 
was present at the incident, stated that the occurrence was due 
to an indiarubber jointing ring used in the pneumatogen at 
Gneisenau colliery ; and that, in order to prevent such incidents, 
the indiarubber jointing material had been replaced by asbestos. 



DISCUSSION OF MR. E. S. WOOD'S PAPER ON " SINKING 
THROUGH MAGNESIAN LIMESTONE AND YELLOW 
SAND BY THE FREEZING-PROCESS AT DAWDON 
COLLIERY, NEAR SEAHAM HARBOUR, COUNTY 
DURHAM."* 

Mr. E. S. Wood said that during the previous discussion a 
question was asked about the lowest temperatures that had been 
observed for freezing shafts, and why temperatures down to 
— 34-4° Cent. (—30^ Fahr.) were not used. He asked the con- 
tractors to give their experience in the matter, and they stated 
that many experiments were carried out in Holland to produce 
lower temperatures in the freezing-tubes by the direct expansion 
of anhydrous ammonia or carbonic acid. Temperatures of — 18^ 
to -210 Cent. (-O40 to -S'S^ Fahr.) were adopted in order to 
keep the freezing-tubes sound, because long experience had shown 
that with lower temperatures the freezing-tubes in many 
instances were broken. In one case, the temj^rature of the brine 
was lowered to— 30^ Cent. ( — 22^ Fahr.) because running water 
was circulating in the strata round the freezing-tubes ; the water 
was frozen, but a high percentage of the pipes were broken. The 
plant used at Dawdon was capable of working at much lower 
temperatures, but it was advisable not to do this in order to save 
the freezing-tubes from being broken. 

Mr. F. CouLSON (Durham) said that the variation of the water 
in the pit as compared with the tides seemed somewhat remark- 

• Tran$. Inst. M. E,^ 1906, vol. xxxii., page 651 ; and vol. xxxiii., page 197. 



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252 DiscirssiON — sinking by the freezing-process. 

able, and perhaps Mr. Wood could give some theory to account 
for it. Did the water in the pit rise in exact proportion to the 
tide, or was there any difference in the speed of rising ? They 
found that, with tides varying from 14 to 17 feet, the water in 
the pit only varied about 4 inches. He would like to know, 
if possible, how this variation of rise and fall in the water varied 
with the rise and fall of the barometer, if that had been observed. 
It seemed to him that the attraction that made the tides might 
have some influence on the large mass of water that was located 
in the Magnesian Limestone ? It seemed curious that the rise 
and fall of the water in the shaft was the same before the sand- 
feeders were tapped, and that the sand-feeders rose to a level 
4 feet higher than the Magnesian Limestone feeders. He would 
be glad to know the cause of this. 

Mr. R. SuTCLiFFE (Bamsley) asked whether the rising water 
in the shaft might not be retarded by the inlet through the sand. 
If the spaces through which the water flowed were very con- 
tracted, it could not enter in anything like the proportion of the 
movement of the tides. Thus, 8 inches in 17 feet represented 1 
in 26 ; and if the time when the tide was in did not permit of 
more water getting into the pit during that time, it could not 
rise so high. With respect to the attraction of the moon or sun 
causing the rise of water in the strata of the earth, the rise of the 
tide was almost enough to indicate that this was not so. There 
was not a tidal variation of 17 feet out at sea, but part of the 17 
feet would be caused by the land-resistance, causing an excessive 
rise through the momentum of the water set in motion by the 
tides, and the amount of water getting into the shaft would 
depend on the openings in the stone to admit it. He did not see 
how the attraction of the sun or moon would affect the rise of 
the water, without affecting the barometer much more, which it 
had not done. 

Mr. M. Walton Brown said it occurred to him that the varia- 
tion was not altogether due to the tide, but might be due to a 
variation of the hydraulic gradient, caused by the water in the 
strata being dammed up by the rising tide, and being released 
by the falling tide. This would occur if the level of the water 
in the shaft corresponded with the level of low water. 



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DISCUSSION — SINKING BY THE FEEEZING-PROCESS. 25S 

Mr. F. CouLSON said that the water in the shaft continued to 
rise for 3 hours after the turn of the tide, and it appeared to him 
that on the tide falling, the shaft being only a short distance 
from the sea, the water ought to start to fall again, but it did 
not do so. The highest rises of water in the shaft occurred with 
a low barometer. There was a \i ell at Sunderland, some dis- 
tance from the sea, where the level of the water in the sand, about 
45 feet above sea-level, used to rise and fall 4 inches with the 
tides. It might be caused by tides backing the water, but he 
did not see how this could take place without stopping the 
outlet. 

Mr. E. S. Wood said that the rise and fall of the water in the 
shaft was carefully recorded ; and, as Mr. Coulson had pointed 
out, it wa« at its highest about 3 hours after the tide was at its 
height. It gradually followed the rise and fall of the tide. 
The saltness of the water, when they were pumping, seemed to 
indicate that some of the gullets were connected directly with 
the sea, and that would account for the tidal variations of level. 
The fact of the water rising above the previous water-level, on the 
bore-holes passing through the Magnesian Limestone into the 
sand, might be owing to the outcrop of the sand, at the surface 
inland, being at a higher level than the water in the Magnesian 
Limestone on the coast. In that case, there was a flow of water 
from the higher level inland towards the sea, and the outlet at 
the shaft would naturally cause the water from the sand and 
below the Marl Slates to rise. 

The P&ESiDENT (Mr- J. H. Merivale) said that the points raised 
in the discussion were interesting, and Mr. Coulson might find 
that the forces which originated the tides would necessarily tend 
to cause similar tides in the water contained in the earth's crust. 



Mr. EiCHAHD Hahle's paper on the " Treatment of Dust in 
Mines, Aboveground and Belowground" was read as follows: — 



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254^ TEEATMENT OF DUST IN MINES. 



TREATMENT OF DUST IN MINES, ABOVEGROTJND AND 
BELOWGBOUND* 



Bt RICHARD HARLE. 



The recent explosions in mines undoubtedly confirm the 
opinion that " where there is dust there is danger/' they prove 
that newly-made dust can easily be ignited with explosive vio- 
lence, and they show the danger of using naked lights in dusty 
mines. 

It is admitted that dust-accumulations are derived from the 
tops of loaded tubs in transit out-bye, on meeting the intake air ; 
by the running of empty tubs in-¥ye ; and dust caused by screen- 
ing aboveground finds its way into the mine, and is deposited on 
all timbers, pillarings, floors and other places on the main roads. 

The writer has been continually reminded of the destructive 
efit'ects of explosions, and has seen so much of the dangers of dust, 
that he has endeavoured, in respect equally of its removal, its 
prevention and watering, to improve and get rid of the danger 
by a new system of damping and spraying, at the places above 
and belowground, where it is made. 

With the view of preventing accumulations, the writer has 
previously described a method of dealing with dust by auto- 
matically sprinkling the tops of loaded tubs, before leaving the 
in-bye stations.! That arrangement has been in use at Browney 
and South Brancepeth collieries for a number of years, and it 
has done much to prevent accumulations of dust on the road-ways, 
along which the coal is conveyed. 

Another mode has recently been perfected to deal with the 

dust-danger aboveground and belowground ; it can be applied at 

any place wherever fine water-spraying is required for damping 

or cooling ; and, by its means, the damped dust is arrested and 

kept secure in the tubs during transit on the main roads from 

the in-bye landings to the shaft. 

* Application for British patent, February 13th, 1007, No. 3,612. 

+ '* Automatic Sprayer for Preventing Accumulations of Dust in Mines," by 
Mr. R Harle, Trans. Inst, M. A'., 1899, vol. xviii., page 113. 



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TREATMENT OF DUST IN MINES. 255 

The new arrangement provides wet zones of misty spray on 
ihe wagon ways, traversed by the tubs; dampens both full and 
empty tubs, and moistens the dust so as to ensure its removal 
out of the pit ; and the air, periodically saturated as it goes in- 
l>ye, deposits sufficient nioisture to damp any other dust. 

The distributors can be fixed to stand-pipes and applied to 
screens, coal-tipplers, coal-conveyers, coal-drawing shafts, or 
other places aboveground, to moisten the dust at any point where 
it arises, and to prevent it from getting into the mine. 

The apparatus can be fixed at any intervening space on under- 
groimd roadways, at junctions, at rope-oflftakes, and where one 
haulage-road joins another, so as to isolate each district, and at or 
near the shafts or in-bye stations. The water is delivered at a 
high pressure, and is pulverized by the action of the distributors, 
for the precipitation of dust. 

The new apparatus works automatically, and can be applied to 
both main-and-tail-rope or endless-rope systems of haulage. The 
spraying continues during working hours, so long as the tubs are 
travelling, and ceases at the end of the shift, when no coal is in 
transit. 

The arrangement consists of a small pump, about 2 inches in 
diameter and 6 inches stroke, with gearing and attachments, 
eapable of delivering sufficient water, at a pressure of about 100 
pounds per square inch, to a spray-pipe, | inch in diameter, placed 
in the gallery, and fitted with nozzles and distributors to pulverize 
and distribute the water equally over the surrounding surfaces. 
The approximate quantity of water pulverized from each nozzle 
and distributor is about 1 quart per minute, under a pressure of 
100 poimds per square inch ; and it can be varied according to 
the pressure, and to the size of the hole in the nozzle. 

On the roadways where coal is conveyed by main-and-tail- 
rope haulage (figs. 1, 2 and 3, plate ix.), the drum or friction- 
wheel, A, is actuated preferably by the movement of the tail- 
Jiaulage rope, B, arranged by pulleys, C and D, to pass over or 
under the wheel. A, at a point near to the pump, G, gear- 
wheels, E and F, and water-tank, H. The water-pressure is con- 
trolled by a valve, J, on the delivery-pipe, K ; and the water can 
be delivered at a pressure of 100 pounds per square inch (figs. 4, 
-5 and 6, plate ix.). The delivery pipe is fitted with nozzles, L, 



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256 



TEEATMENT OF DUST IN KIXES. 



arranged to produce a fine spray, botk in-bye and out-bye. 
wet zone can be extended to a length of 150 feet or more in eitlie 
direction, by extending the spraying or outlet pipe. 

The method of spraying where endlees-rope haula^ is in ub 
is shown in figs. 7, 8 and 9 (plate ix.). In this case, a suitable 
length of rope or chain. A, is arranged on the tub-way, and 
carried round a drum or sheave, B. The apparatus is controlled 
and kept in motion by the tubs as they pass over the chain, there 
by working the shafting and gearing in connection with th€ 
pump, G, and keeps a continuous spray in the g^lery as the 
tubs pafis along. Water is stored in the tank, D ; and forced bj 
the pump, C, through the pipe, E, and regulating-valve, F, to the 
pipe, G, fitted with nozzles, H, producing a misty spray, both in- 
bye and out-bye (figs. 10, 11 and 12, plate ix.). The wet zone^l 
can be extended to a length of 150 feet or more in either direc-| 
tion, by lengthening the spray or outlet pipe. 

The author has designed two patterns of nozzles and water 
distributors for attachment to the pipe6 of the automatic water- j 
spraying apparatus. In the first design, the nozzle, A, made of | 
pipe I inch in diameter, is screwed into the water-supply pipe; 
B, is a barrel or drum, fitted with blades or vanes, C, and carried 
by the bridle or supporting straps, D, attached to the nozzle by 
the screw or rivet, E (figs. 13 and 14, plate ix.) The second 
design is similar in every respect, except that the drum or barrel,. 
B, is fitted with a diverting ring, F, which materially assists in 
the formation of the water-spray (figs. 15 and 16, plate ix.). The 
dimensions of the nozzle and of the distributor may be varied to 
suit any diameter of pipe or flow of water. 

The working of the machines show the following ad- 
vantages : — 

(1) Sprayed and well-watered zones, over long distances, are- 
produced at any suitable place in the galleries or main roads. 

(2) Each district can be isolated ; and, in case of an explosion 
of gas, damage to roadways and air-crossings will be prevented,, 
the loss of life will be greatly minimized, and the entry of fresh 
air into the mine will be facilitated. 

(3) The dust, kept moist and secure in its transit in tubs on 
the wagt)nways, is carried out of the mine, just as in damp mines,, 
where no trace of dust is found. 



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DISCUSSION — ^TREATMENT OF DUST IN MINES. 257 

(4) There is no excessive watering or wetting of coal. 

(5) It obyiates the danger of dust accumulating in the 
galleries, and prevents it from being carried in-bye to the face- 
workings. 

(6) The distributors prevent, when placed aboveground, the 
removal of dust, which is found at screens and other places above- 
ground, and prevent it from moving about the shaft and passing 
down the pit. 

(7) There is no waste of coal or dust in screening, or in 
conveying it to the coke-ovens; and explosions are prevented 
in coke-ovens and other places aboveground. 

(8) The cost of upkeep and supervision is almost nily and the 
system will save labour and cleaning of roads. 

(9) It requires little, if any, extra space to fit it on the main 
roads. 

(10) The coal-dust is arrested at the source, and absolute 
safety is afforded against sweeping explosions. 



The President (Mr. J. H. Merivale) said that one of the 
most important problems in connection with the question of 
watering was the effect of damping the roads, as it might cause 
heaving and other injury in the mine. It seemed to him 
that the arrangement proposed by Mr. Harle would very largely 
overcome the difficulties, as, instead of damping the floor, it would 
simply damp the coal on the top of the tubs. The greater part, 
probably the whole, of the dust distributed on haulage-roads 
must necessarily come from the sets of tubs, or be blown down 
the shaft from the screens; and, by damping the coal on the 
sets of tubs, the dust would be prevented from accumulating on 
the ground and causing those difficulties, which arose from the 
use of water on haulage-roads. 

Mr. E. S. Wood (Dawdon colliery) endorsed what had been 
said by the President about the use of water-sprays in mines, 
as, in some mines in the county of Durham especially, undue 
watering of haulage-roads would materially affect both the roofs 
and sides; but, at the same time, watering seemed to be a step 
in the right direction. There could be no doubt that coal-dust 
was a source of great danger in coal-mines. The danger might 



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258 DISCUSSION — TREATMENT OF DUST IX MINES. 

be reduced by providing proper tubs, with absolutely tight 
bottoms, so that coal-dust could not get out on to the haulage- 
roads, upon which the tubs were travelling. And further, the 
provision of distinct and separate wet zones in the different dis- 
tricts might, in the case of an explosion, absolutely prevent the 
explosion from being carried over the wet zone. The apparatus 
described in Mr. Harle's paper might be adapted to a certain 
extent to making such a zone immediately under the water-spray. 
A distance of 450 to 600 feet in the vicinity of the water-spray 
might be arched and made absolutely wet without damaging the 
floor of the seam and causing heaving, and it would obviate the 
probability of an explosion passing beyond that wetted area. 
These watering arrangements could be placed at the different 
engine-landings, and at some collieries they might be placed near 
the working-places. He suggested further that portions of the 
haulage-roads should be converted into absolutely wet zones. 

Mr. C. C. Leach (Seghill colliery) said that he had sent 
samples of dust from haulage-roads for analysis, and he was asked 
why coal-dust had not been sent. This dust had been actually 
collected by himself from the roofs and sides of haulage-roads. 
He thought that it chiefly consisted of clay and shale, with a 
little coal-dust. He thought that water-spraying could be 
done, without special machinery ; and water under pressure from 
the surface would make a more efficient spray than would be pro- 
duced by a small pump. He did not quite agree with Mr. Wood 
that haulage-roads could be sprayed without injury. Watering 
would be chiefly required, in wide places, at the junctions of 
haulage-roads, and the effects would sometimes be very injurious. 

Mr. T. C. FuTEES (Newcastle-upon-Tyne) said that Mr. Harle 
claimed that his arrangement would prevent the accumulation 
of dust on the heapstead. The apparatus would simply spray 
the top of each tub EUi it passed underneath it, and consequently 
he did not see how the coal inside the tub would be sufficiently 
damped so as to prevent the dust from rising, especially on the 
jigging-screens, where it would cloud the air and finally pass 
down the shaft. 

Mr. C. H. Steavensox (Redheugh colliery) said that the 
arrangement was very ingenious, and the members werfe indebted 



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DISCUSSION — ^TREATMENT OF DTJST IN MINES. 269 

to Mr. Harle for bringing it to their notice ; but he did not think 
that watering was the solution of the difficulty. He had found 
that the watering of roadways had a most injurious e£Eect upon 
them ; and, although that method suited some collieries, it was 
necessary to discover some means of removing the dust without 
watering it. It was possible that it might be enacted by Parlia- 
ment that dust should be removed by brushing ; but it occurred 
to him that it might be possible to remove dust from mines 
by means of suction-machines, similar to those used for cleaning 
carpets. 

Mr. C. C. Leach (Seghill colliery) asked what was the cost of 
cleaning a square yard of carpet, and then only a few ounces of 
dust would be removed. 

Mr. T. C. FuTEBS said that such an arrangement had already 
been successfully applied to a screening-plant: a series of suc- 
tion-pipes were applied to the jigging-screens, and all the dust 
was withdrawn from the screens and so prevented from going 
down the pit. 

Mr. R. SuTCLiFFE (Bamsley) said that the removal of dust 
by brushing in a strong current of air would result in the dust 
being carried in larc^e quantities into the working-places, and that 
would be increasing the danger. 

Mr. F. CouLSON (Durham) said that if the water-spray was 
used in a length of haulage-road, arched with brickwork, so as 
to prevent crushing owing to the action of the water, and the 
space kept damp, it would stop any coal-dust explosion; but a 
severe gas explosion would be carried through any moderate 
length of damp ground. In any case, a wet zone would not pre- 
vent the after-damp from passing from the vicinity of the actual 
explosion into other districts. He suggested that tub-grease 
might render coal-dust more explosive, and pointed out that on 
an ordinary haulage-road hundreds of tons of tub-grease were 
used and ground and mixed with the coal-dust. He moved 
a vote of thanks to Mr. Harle for his interesting paper. 

Mr. C. C. Leach seconded the resolution, which was cordially 
adopted. 



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260 



DISCUSSION — ^TREATMENT OF DUST IN MINES. 



Mr. B. Habxe, replying to the discussion, wrote that the 
sprayers were being efficiently used at the collieries under his 
charge, and it was found that no injury was done to the roadways 
by the dewy spraying. No walling <»r arching was required in 
the dustless zone. His best reply to all other questions and 
criticism on the performance of the invention would be by a 
practical demonstration of the working of the apparatus ; and he 
would be very pleased to show it in use to any of the membenB. 



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DISCUSSION — ^THE HIDDEN COAL-FIELDS OF THE MIDLANDS. 261 



THE SOUTH STAFFOEDSHIRE AND WABWICKSHIRE 
INSTITUTE OF MINING ENGINEERS. 



GENERAL MEETING, 
Held at thx Untyxrsitt, Birmingham, Junk 4th, 1907. 



Mb. F. a. GRAYSTON, President, in the Chair. 



The minutes of tlie last General Meeting and of Council 
Meetings were read and confirmed. 



The following gentlemen were elected : — 

Associate Member— 
Mr. H. Sharrock Hiooinbottom, Colliery Proprietor, African Houae, 
LiverpooL 

Students — 
Mr. Victor Holmes McNauohtbn Barrett, Etruria Vicarage, Stoke-upon. 

Trent. 
Mr. G. BAiiiiJE Hill, Gillott Road, Edgbaston, Birmingham. 



DISCUSSION OF PROF. C. LAPWORTH'S PAPER ON 
"THE HIDDEN COAL-FIELDS OF THE MIDLANDS."* 

The President (Mr. F. A. Grayston) remarked that Prof. 
Lapworth stated that **all the visible coal-fiel.ls [of the Midlands] 
are simply the exposed coal-bearing portions of what once was 
a continuous sheet of Carboniferous strata. . . . afterwards 
covered by a similarly continuous sheet of red Triassic rocks." 
He confessed that he was unable to reconcile this theory with 
the fact that the Carboniferous strata were frequently found 
to be unconformable with the overlying Triassic rocks : the 
latter, in Warwickshire, having generally only a slight inclina- 
tion. It was true that Prof. Lapworth further stated that al- 
though this view was " adequate enough as a working generaliza- 

• Trans, Inst. M. E,, 1907, vol. xxxiii., page 26. 



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262 DISCUSSION — ^THE HIDDEN COAL-FIELDS OF THE MIDLANDS. 

tion, it is insufficient if the details be examined," and mentioned 
that there were large areas, like some near Chamwood, where 
" the Coal-measnre sheet was swept ofiE before the Triassic 
sheet was laid down;"* and later, he stated that in some 
districts the Coal-measnres had been subjected to distortion and 
subsequent denudation before the Triassic rocks were deposited.t 

It appeared desirable in considering the question of the hidden 
coal-fields that all information possible should be obtained to 
assist in forming an opinion as to the condition of the Coal-mea- 
sures below the Triassic rocks. The late Sir Andrew C. Ramsay- 
said, referring to the basin-shaped form of the Coal-measures, 
"the reason of this is that the Carboniferous strata were dis- 
turbed and thrown into anticlinal and synclinal folds, before the 
beginning of Permian and New Red Sandstone times.^t Sir 
Charles Lyell considered that the amount of volcanic energy was 
great at certain epochs of the Carboniferous age ; and that 
enormous curving and dislocation of the Carboniferous rocks 
and great denudation of their exposed surfaces occurred before 
the deposit of the Permian rocks.§ He (Mr. Grayston), how- 
ever, believed that Prof. Lapworth's researches prevented his 
going as far as the above-named authorities on the question of 
the disturbance of the Carboniferous rocks prior to the Permian 
and Triassic periods, at all events, so far as the Midland coal- 
fields were concerned. He (Mr. Grayston) assumed that the 
Birmingham basin, referred to by Prof. Lapworth, formed one of 
the troughs described at the beginning of the paper. He, 
therefore, asked Prof. Lapworth, whether he could give any 
reason why the boring at Packington, which was fairly centrally 
situated in the basin, showed a much less thickness of red rock 
than that at Streetly, which was nearer to the edge of the basin 
and within 2^ miles of the eastern boundary of the South 
Staffordshire coal-field. 

It was also stated that " judging from the manner in which 
the coal-seams thin away towards Wyken and Craven, it can 
hardly be expected that they will extend in workable thickness 

• Trafu. Inst. M, E,, 1907, vol. xxxiii., page 27. 

+ Ibid., page 35. 

X The Physical Oedogy and Geography of OrecU Britain, by Prof. A. C. 
Ramsay, third edition, 1872, page 301. 

§ The Student' Jt Elements qf Geology, by Sir Charles Lyell, Bart., third 
edition, 1878, page 388. 



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DISCUSSION — ^THE HIDDEN COAL-FIELDS OF THE MIDLANDS. 268^ 

far south of the latitude of Coventry."* He would be glad to 
know Prof. Lapworth's reasons for concluding that the Coal- 
measures would become less productive to the south of Coventry^ 
because the coal at Wyken colliery was thicker than at other 
collieries in that district.t He (Mr. Grayston) did not take 
into consideration the thickness of the coal-seams below the 
Slate coal-seam, as they were not generally proved or worked 
in that district. The actual thickness of coal at Wyken col- 
liery (section No. 5), from the bottom of the Slate coal-seam to 
the top of the Two-yards coal-seam was 26 feet, exclusive of 8 
feet of ground occupied by partings.^ At Hawkesbury colliery 
(section No. 10), the thickness of the same coal-seams was 24 
feet 8 inches, exclusive of partings; at Hawkesbury colliery 
(section No. 13), the thickness was 21 feet 6 inches under the 
same condition; and at Bedworth colliery (section No. 12), 2^ 
feet.§ 

It was also stated that " the productive measures are perhaps- 
in their greatest force along a line drawn across the basin from 
Aldridge towards Tamworth."|| Possibly that was so, but he 
(Mr. Grayston) suggested that the Thick coal-seam of Stafford- 
shire, which he considered to be identical with the Two-yards, 
and the Slate coal-seams and the intervening coal-seams of 
Warwickshire, would probably be found in a more or less direct 
line from Sandwell Park to Hawkesbury, subject, of course, to 
the possibility of disturbance and denudation. 

Mr. T. H. Bailey (Birmingham) said that, in 1865, his father,. 
Mr. S. Bailey, instructed by the Earl of Dartmouth, sank a bore- 
hole, near Newton Road railway-station, over the eastern bound- 
ary fault of the South Staffordshire coal-field ; and a trial-shaft 
passed through 40 feet of coal, evidently the upturned coal- 
seams forming the Thick coal of South Staffordshire. Prom 
his studies of the district he had little doubt that the Thick 
coal-seam extended from Sandwell Park in the South Stafford- 
shire coal-field to Hawkesbury in the Warwickshire coal-field. 
The occurrence of SpirorbisAim.estoiie being an indication of 

• Trans. huU M. E., 1907, vol. xxxiii., page 44. 

t "Vertical Sections of the Warwickshire Coal-field," Qeologiccd Survey of 
Great Britain, Vertical Sectims, Sheet No. 21, 1857. 

t Ibid, § Ibid. 

II Trans. Inst. M. E., 1907, vol. xxxiii., page 45. 



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^64 DISCUSSION — ^THE HIDDEN COAL-FIELDS OF THE MIDLANDS. 

underlying Coal-meafiures, he asked whether there were great 
variations of depth between the Sjnrarbis-limesixyne and the coals 
of the South Stafiordshire Thick coal-seam. 

Mr. Alexander Smith (Birmingham) said that Mr. F. A. 
Orayston's " President's address,"* dealing with the Warwick- 
shire coal-field, might be discussed with Prof. Lapworth's paper. 
He could not help being impressed by the accuracy of the geolo- 
gical surveys of the South Staffordshire coal-field by Prof. J. 
Beete Jukes,t and the Warwickshire coal-field by Mr. H. H. 
Howell, + and their memoirs were still serviceable and indispens- 
able to mining engineers at the present day. 

A remarkable section of coal-seams had been proved in the 
Lower Coal-measures at the Tunnel pits of the Haunchwood 
colliery ; and appeared to form the bottom of the basin at that 
part of the Warwickshire coal-field. The Coal-measures at Arley 
colliery rose rapidly westward towards the great north-and-south 
fault. § In the bore-hole at Packington, the coal-seams occurred 
at the depth of 1,800 feet (nearly double that at Arley, 990 feet), 
and nearer the north-and-south fault, yet there was no evidence 
that the coal-seams were rising towards the surface. He eon- 
firmed the President's (Mr. Grayston's) statement as to the thick- 
ness of the coal-seams at Wyken and Craven collieries; it 
certainly proved that the seams were not thinning out at 
"Coventry ; and it was favourable to their continuance southward 
for a longer distance than Prof. Lapworth anticipated. 

Mr. Daniel Jones (Shifnal) said that Prof. Lapworth had 
•done great service in laying before the members a survey of 
the more or less associated and kindred coal-fields of the Mid- 
lands. For want of opportunity in making a wide study, mining 
engineers were prone to generalize from insufficient data, and 
to draw conclusions from observations gleaned in their own coal- 
field. Now, Prof. Lapworth had spread before them a Carboni- 
ferous tract with its superincumbent strata removed, and proved 

• Trans. Inst. M. E,, 1906, vol. xxxii., page 312 and plate xiv, 

t ** On the Geology of the South SUffordshire Coal-field," by Prof. J. Beete 
Jukes, Museum of Practical Oeology and Geoiogical Survey/ : Beeorda qfthe School 
of Mints and of Science applied to the Arts, 1863, vol. L, page 149. 

X Memoirs of the Geological Survey of Oreat Britain and of the Musevm of 
Practical Geology : The Geology qf the Warwickshire Coal-field atid the Permian 
Hocks and T'rias of the Surrounding District , by Mr. H. H. Howell, 1869. 

§ Trans. Inst, M, E,, 1906, vol. xxxii., page 316. 



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DISCUSSION — ^THE HIDDEN COAL-FIELDS OF THE MIDLANDS. 265 

ihat the coal-fields generally spoken of as separate formed one 
homogeneous whole. The contents of this area could only be 
approximately determined ; and the contour of the pre-Carboni- 
ferous basin, and the eflEects of denudation at varying periods, 
-could not be ascertained by theoretical reasoning. 

The Symon fault of the Shropshire coal-field was an illus- 
tration of extensive denudation. It was traceable from the 
Woodhouse pits of the Lilleshall company by Stirchley and the 
Hem pits, and had shorn off the whole of the southern end of 
the Coalbrookdale coal-field. Southwards, in the Forest of Wyre 
coal-field. Upper Coal-measures only were found resting on an Old 
Red Sandstone base ; until at Billingsley and Highley a consider- 
able area of the productive coal-seams of the lower part of the Coal- 
brookdale series occurred. Outliers of similar productive 
•coal-seams occurred at Shirlot, and in the Brown Clee and the 
Titterstone Clee coal-fields. It was evident that, as originally 
laid down, the productive coal-seams extended far away westward 
•over the Old Red Sandstone base. From his (Mr. Jones') re- 
searches, it would appear that this particular denudation must 
have taken place at the close of the formation of the Middle 
Coal-measures and before the Fpper Coal-measures were laid 
down ; but no one could determine how far it had extended east- 
ward in denuding the productive coal-seams. It was even 
possible that the Coalbrookdale coal-field was only an island of 
Coal-measures similar to those of Shirlot, Highley and the Clee 
Hills. The boring at Claverley did not prove productive coal- 
seams, but that might have been due to two causes : (1) The high 
level of the original Silurian base or (2) the denudation of the 
older Coal-measures. There could be no doubt that productive 
coal-seams did exist between the Baggeridge pits and some 
undetermined point westward. This illustration of denudation 
supported the wise remarks made by Prof. Lapworth by way of 
caution to mining engineers, and he could speak from his own 
experience in three different cases where considerable expendi- 
ture had been incurred in boring with futile results. The bore- 
holes were first made and the geologist was consulted afterwards, 
thus putting the cart before the horse. 

Prof. R. A. S. Redmayne (Birmingham), referring to the 
statement made by Piof. Lapworth, on the authority of the Royal 

VOL. XXXIU.-1906.1907. 21 



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DISCUSSION — THE HIDDEN COAL-FIELDS OF THE MIDLANDS. 

Coal Commission, that the limit at which coal could be profitably 
worked was 4,000 feet, said that recent developments in Belgium 
tended to disprove this, as some collieries were already very near 
the said limit and were being extensively and profitably worked. 
The greatest difficulty in the way of deep coal-mining was the 
heat-increment, but he thought that it did not say much for 
science if, in the near future, cheap and practicable means were 
not discovered to minimize that difficulty. Furthermore, the 
variation in the rate of increase in the temperature in point of 
depth was very great as between district and district, and so far 
no satisfactory explanation for this difference was forthcoming. 
He (Prof. Redmayne) remarked that at the Tamarack copper- 
mine, in Michigan, U.S.A., a depth of 5,100 feet had been at^ 
tained, and no difficulty was experienced from the temperature, 
which was but slightly increased. He (Prof. Redmayne) asked 
Prof. Lap worth how far, in his opinion, workable coal extended 
in the direction of Frankly Beeches, near Halesowen. Mr. G. 
H. Timmis' Witley colliery, not shown on the map of the Geolo« 
gical Survey, proved the existence of workable coal further than 
was originally expected ; but, at the same time, it showed, owing^ 
to the rise of the measures in the direction mentioned, that the 
limit of workable coal had been very nearly reached in this part 
of the coal-field. 

Mr. J. C. Forrest (Wolverhampton) said that the faults on 
the west of the Cannock-Chase coal-field were not correctly 
indicated on the maps of the Geological Survey. The western 
fault, north of Wolverhampton, had not, as was once supposed^ 
a big downthrow; and south of Wolverhampton, it had not 
been proved, but the indications seemed to show that there would 
be a big downthrow beyond the Baggeridge area, as the fault 
seemed to increase in size going southward. In an area on the 
western side of Cannock Chase, there was sometimes an upthrow 
fault, and then, of course, a much larger downthrow fault. At 
other places, there was a verj^ heavy dip in the measures, all to 
the westward, and all leading down to what was no doubt the 
original level of the coal-field. These indications showed that 
the Cannock Chase coal-field and that of South Staffordshire 
were formerly raised from a lower level, and, in consequence, 
the edges on the east and west sides, where the break took 



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DISCUSSION — ^THE HIDDEN COAL-FIELDS OF THE MIDLANDS. 267 

place, were ixot necessarily clean cut, but rather the reverse. 
There would be areas, as had been proved at Baggeridge on 
one side and at Pelsall and Walsall Wood on the other, where 
the upheaval from the lower level had not raised the coal-seams 
to the ordinary level of the surrounding country. But the fact 
remained that to reach workable coel-seams on the west or on 
the east, the level at which the highest workable coal-seam would 
be found under the New Red Sandstone would be about 2,000 
feet below sea-level. 

In a general way he asked Prof. Lapworth, if east-and-west 
lines were drawn across the coal-field, whether the coal-seams 
found along such lines were, as a rule, of much the same thick- 
ness and quality as they were found in the centre, taking that 
centre either in the South Staffordshire coal-field or in Cannock 
Chase as the case might be. For instance, taking a line from 
Baggeridge to Sandwell Park, one would expect that the some 
seams would be found to the west of Baggeridge as to the east 
of Sandwell Park, allowing, of course, for variations caused by 
distance and by what had been proved, say, on the west in the 
Highley or Shropshire coal-fields and on the east in Warwick- 
shire, on the same east-and-west line of section. Similarly also, 
on drawing an east-and-west line across the centre of the Cannock 
Chase coal-field, the coal-seams to the west would be much the 
same, allowing, similarly, for the change already proved in the 
coal-seams worked in Coalbrookdale and district, and on the 
east by the seams proved along the same east-and-west line in 
Warwickshire. He thought, also, that it would be admitted 
that the coal-seams were more in number and of greater thick- 
ness, altogether, in the north than they were in the south, where, 
eventually, they died out. In the west, a very uncertain and 
large barren area appeared to extend to the east of the Shropshire 
coal-field, and he suggested that this barren area, or its cause, 
extended southward on the east side of the Highley coal-field. 

North of the Cannock Chase coal-field, and between it and 
the North Staffordshire coaJ-field, there was a very uncertain 
area which carried with it many conditions like the area lying 
eastward of the Shropshire coal-field. He asked Prof. Lapworth 
whether he had found, under the Coal-measures in any of the 
coal-fields, beds of red rocks which yielded considerable bodies 
of brackish water. 



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268 DISCUSSION ^THE HIDDEN COAL-FIELDS OF THE MIDLANDS. 

Mr. G^RGE M. CocKiN (Rugeley) asked Prof. Lapwortli 
whether recent geological evidence proved that rocks, older than 
the Coal-measures, cropped out under the New Red rocks in the 
northern parts of the basin lying between the northern end of the 
Cannock Chase coal-field and the Leicestershire coal-field. Prof. 
Lapworth said that Spirorbis-limesione bands were characteristic 
of the Keele series and the Upper Coal-^jeasures ; but Mr. J. T. 
Stobbs had discovered them in true Coal-measures as low down as 
the Bowling Alley coal-seam in North Staffordshire, and he 
(Mr. Cockin) had recently been able to locate a well-defined band 
of S pirorbis AiTdesione in the Cannock Chase Coal-measures, near 
the Main Hard or Old Park coal-seam.* 

Mr. S. F. SoPWiTH (Cannock Chase) said that Prof. Lapworth 
spoke of the probability of the productive Coal-measures of the 
Cannock Chase district pinching out altogether, beneath the Red 
rock covering, in a north-easterly direction; and that the pro- 
ductive Coal-measures were absent also under the Red rocks in 
the northern part of the Birmingham basin. Consequently a 
large part of the Mid-StafEordshire basin, lying to the eastward, 
would be barren of productive Coal-measures. He asked Prof. 
Lapworth whether this inference was correct, and whether any 
theories had been advanced as to the probable limits of the 
Coal-measures in this basin. 

Prof. C. Lapworth said that the President (Mr. Grayston) 
had with great judgment addressed himself to the most vital 
points of his paper. If, considered as a whole, the Carboniferous 
rock-sheet did not, as the newer generalization implied, share in 
the fold-arches and fold-basins of the Triassic rock-sheet con- 
sidered as a whole, then it was idle to expect that in these great 
basins there would be found more or less continuous hidden coal- 
fields, extending from one visible coal-field to ajiother. And 
further, as formerly suggested by some authorities, if the Car- 
boniferous rock-sheet had .been finally folded and denuded before 
Triassic time, the newer generalization that Carboniferous and 
Triassic rock-sheets were folded in combination, appeared to be 
in conflict with the known facts. It might be replied that this 

* •* On the Occurrence of Limestone of the Lower Carboniferous Series in 
the Cannock Chase Portion of the South Staffordshire Coal-field," by Mr. George 
Marmaduke Cockin, The Quarterly Journal of the Geological Society of Lond<m^ 
1906, vol. Ixii., page 623. 



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DISCUSSION — ^THE HIDDEN COAL-FIELDS OF THE MIDLANDS. 269 

conflict was only in appearance. All these views were natural 
and harmonious enough if considered as summarizing parts of 
the whole truth, and as stages in the growth of knowledge. The 
earlier generalization of Sir Andrew Ramsay and Sir Charles 
Lyell that the Coal-measures were thrown into anticlinal and 
synclinal forms and denuded before the Permian rocks were 
deposited, still held good so far as the true Permian rocks of 
Yorkshire were concerned. But it had been disproved, with 
respect to the so-called Permian (or Keele beds) of the Midlands ; 
for, as Mr. Walcot Gibson and others had shown, these followed 
at once conformably upon the underlying grey Coal-measures, 
of which, indeed, they formed merely the upward continuation. 
Again, the further generalization of the authorities, that so 
great a folding and denudation of the Carboniferous rocks 
took place before Triassic time, that the Carboniferous and 
Triassic sheets (spoken of collectively) were everywhere uncon- 
formable with respect to each other, parts of the former being 
absent altogether in some districts, had never been disputed. 
But during these pre-Triassic movements, it should be remem- 
bered that the Carboniferous rock-sheet was bent into synclines 
as well as anticlines, and in these synclines it would remain un- 
denuded. And more, it must be remembered that the collective 
Carboniferous rock-sheet was originally so thick in the northern 
and central parts of the Midland area — the Coal-measures alone 
(including the so-called Permian) being from 3,000 to 8,000 feet 
thick — that only upon the highest anticlines and along the 
margins of the whole Midland basin, where the beds were at 
their thinnest, could it be reasonably argued that it was entirely 
denuded away. It was only natural, therefore, to infer that, 
with these exceptions and others of minor note, a more or less 
continuous Carboniferous rock-sheet still remained undenuded, 
upon which the Triassic sheet was in its turn deposited, the 
Triassic sheet not only extending over the collective undenuded 
mass of the Carboniferous sheet, but even over those areas from 
which the Carboniferous sediments had been denuded away. 

But the folding movements did not close at the end of Car- 
boniferous times. The Triassic sheet became eventually folded in 
its turn, and in its folds the underlying and still largely con- 
tinuous surviving Carboniferous sheet must necessarily have 
taken part; and from this followed, quite naturally, the newer 



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270 DISCUSSION — ^THE HIDDEN COAL-FIELDS OF THE MIDLANDS. 

generalization. From the arches thus finally formed in post- 
Triassic times, the Triassic rocks had since been swept off by 
denudation, and in these parts consequently, as a rule, occuiTcd 
the visible coal-fields. And in the broad basins developed at 
the same time, and as yet tindenuded, must, if anywhere, lie 
the hidden coal-fields which remained yet to be discovered. 

Of course, this generalization only professed to be a guide on 
a broad and regional scale. There were movements in progress 
during the whole of Carboniferous times, probably over the whole 
of the collective Carboniferous area of which this Midland basin 
merely constituted a part. The Midland basin as a whole was 
then undergoing a general depression, so that the successive 
Carboniferous formations overlapped towards the southern 
margin. At the same time, however, the rate of depression 
seemed to have been much faster towards the central parts, for 
there the formations were thickest, and they all decreased in 
individual thickness southward from the centre. It was by no 
means unlikely, indeed it was highly probable, that this more 
central depression was correlated with a corresponding elevation 
and denudation towards and beyond the margin. And it was 
probable that even the floor of the great basin might have 
been in part locally warped and denuded, as in the case of the 
so-called Symon fault. But these were matters of theory and 
future discovery. At all events, the identity of the succession 
of the sub-formations throughout the Midland basin, and the 
persistence of their lithological characters forbade the assump- 
tion that any^ of the movements during Carboniferous times were 
of an importance sufficient to destroy the unity of the basin as 
a whole. 

The Triassic period was also a period of movement and local 
denudation. The north-western half of the Midland Triassic 
area sank first under the waters, so that the successive Triassic 
formations overlapped each other in turn to the south-eastward, 
until finally nothing but the highest formation — the Keuper — 
was found. As the rate of depression was again most rapid to 
the north and north-west, all the Triassic formations thinned 
away to the south-eastward, so that the Keuper, about 2,000 feet 
thick in Cheshire, was reduced to less than 1,000 feet when it 
finally disappeared under the Lias of Warwickshire. 

All these matters must be borne in mind when employing 



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DISCUSSION — THE HIDDEN COAL-FIELDS OF THE MIDLANDS. 271 

the generalization of the post-Triassic folding and denudation, 
but they left its value as a general guide undisturbed. 

As to the suggested difficulty respecting the borings at 
Packington and Streetly, it must be remembered that, in the 
Birmingham basin as elsewhere, the collective thickness of non- 
productive measures (including the Keele beds) increased to the 
northward, and also that the Birmingham basin was not a 
simple, but a compound basin, somewhat bent and broken by 
folds and faults. At Packington, not only was the floor of the 
basin locally raised from the west, but much of the southern 
Keele series was denuded; and at Streetly, not only were the 
rocks depressed deeply by the great downthrow of the eastern 
boundary-fault lying no great distance to the westward, but 
most of the more northern (and therefore thicker) Keele series 
was present, as well as the overlying Pebble-beds of the Trias. 

It was pleasant to learn that in the southern part of the 
Warwickshire coal-field the coal-seams (at all events, those 
above the Slate coal-seam), did not actually thin away but only 
came closer together at the Wyken and Craven collieries, and 
that consequently there was a reasonable prospect that they 
might continue workable well to the south of the latitude of 
Coventry. Nevertheless, it must be carefully remembered 
how rapidly the corresponding coal-seams of South Staffordshire 
deteriorated and disappeared soon after they came together to 
the south, so that there was especial need for caution. 

As respects the view that productive Coal-measures might be 
found in greatest force between Aldridge and Tamworth, this 
view accorded with the fact that the total thickness of the pro- 
ductive Coal-measures increased northward from the Thick-coal 
country into the country lying well north of the Bentley fault, 
while, to the north-east of this area, the coal-seams begin to 
rise towards the Permian anticline. 

The discovery in 1865, referred to by Mr. Bailey, of the 
existence of the Thick coal-seam at Newton Road railway-station 
to the east of the boundary-fault was a most interesting point in 
the early history of the opening-out of the Birmingham basin. 
Since 1882, when the Carboniferous measures of East Warwick- 
shire were found not to include the Millstone Grit as previously 
supposed, but to be made up of the same succession of forma- 
tions as those of South Staffordshire, while the coal-seams had 



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272 Discrssiox — the hidden coal-fields of the midlands. 

already been proved to come together towards the south in the- 
same manner, it had been acknowledged on all hands (by those 
who had carefully considered the matter) that the Thick coal- 
seam and its representatives probably extended more or less 
continuously under the Birmingham basin into the Hawkesbury 
district. But the exact parallelism of the coal-seams in the two 
coal-fields was still far from being established. 

The behaviour of the coal-seams, referred to by Mr. Alex- 
ander Smith, at the Tunnel shaft, at Arley colliery, and at 
Packington was explained if it were borne in mind that there 
was an upthrow fault and a rise of the beds immediately west of 
Arley. Consequently, the coal-seams at the Tunnel pit lay in 
the bottom of the basin formed between this rise to the west and 
the wellknown natural rise of the outcrop to the east near 
Stockingford. The Packington bore-hole lay away in the area 
on the downthrow side of the Arley fault, and hence the greater 
depth of its coal-seams. 

The well-known Symon fault, to which Mr. Daniel Joi^es 
referred, was doubtless, where it occurred typically in the Coal- 
brookdale coal-field, a denudation-phenomenon, probably preceded 
by folding movements, as Mr. W, J. Clarke had shown.* Mr. 
Jones had done good service in pointing out that the movement 
and denudation might have extended for some distance to the 
south-west and south, and possibly even below some of the Red 
ground of the Wolverhampton basin. But the theory that the 
productive Coal-measures and the underlying Carboniferous 
formations once extended to the Clee Hills and had been 
removed by denudation at the time of the formation of the 
Symon fault, although a fascinating one, was far from being 
as yet established. At all events, the Carboniferous measures 
of the Titterstone Clee coal-field were claimed by some to be 
not those of the type of the Midland basin, but those character- 
istic of the Southland basin, those of the South Wales and 
Bristol coal-fields. 

The new facts as to the behaviour of the western boundarj^- 
fault, brought forward by Mr. J. C. Forrest, were valuable 
additions to knowledge. The line of the fault laid down upon 

* "The Unconformity in the Coal-measnres of the Shropshire Coal-field/^ 
by Mr. WilUam James Clarke, The Quarterly Journal of the Geological Society of 
London, 1901, vol. Ivii., page 86. 



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DISCUSSION — THE HIDDEN COAL-FIELDS OF THE MIDLANDS. 273- 

the old maps of the Geological Survey had long been acknow- 
ledged by some as not marking everywhere the main dislocation „ 
which might in some areas lie very much farther to the west. 
There was much to be said for the view that the dislocation and 
its branches formed in some districts a compound series depres- 
sing the coal-seams to greater and greater depths. 

Doubtless it was to be expected as the coal-seams of South 
Staffordshire varied in number and character, gradually as they 
were followed from south to north; that they would continue 
more or less unaltered in these respects as they were followed 
at right angles to this (or from east to west), not only over the 
visible coal-field but also into the hidden coal-fields on either 
side. But, when this generalization was employed, it should be 
checked by calling to mind the general form of the Midland 
Carboniferous basin considered as a whole, and it might be 
anticipated that, when followed under the Red ground outside 
the South Staffordshire coal-field, the lines of similarity would 
bend more and more northward, at all events in the Wolver- 
hampton basin, in proportion as the distance from the visible 
coal-field increased. 

The presence of saline waters in the Carboniferous and under- 
lying series would form a good subject for a special paper. 

The discovery by Mr. G. M. Cockin of a band of Spirorhis-^ 
limestone in the productive Coal-measures of Cannock Chase 
formed another link in the lengthening chain of evidence bear- 
ing upon the original continuity of the Coal-measures of North 
and South Staffordshire, and one looked forward with growing 
confidence to the time when the coal-seams and marine bands of 
the two districts would be more or less paralleled in detail. While 
it was doubtless true that Spirorbis-Xime^ioriQ bands occurred not 
only in the non-productive, but also in the productive Coal- 
measures, they were apparently much more prevalent in the 
latter than in the former. And as Mr. T. H. Bailey had sug- 
gested, some of the Spirorhis-hoxLHL^ of the non-productive Coal- 
measures where they overlaid the productive series, although 
the examples referred could not be asserted to be absolutely 
constant in position, yet they had nevertheless proved a valuable 
aid in the Southern Midlands in estimating the probable depth 
of the workable underlying coal-seams. 

In reply to Mr. S. F. Sopwith and Mr. G. M. Cockin, it 



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"274 DISCUSSION — THE HIDDEN COAL-FIELDS OF THE MIDLANDS. 

might be pointed out that, where the Pennine anticline was 
overlapped by the Eed rocks of the Stafford basin, from Cheadle 
io Derby, the Carboniferous rocks were denuded, even down to 
the level, locally, of the Mountain Limestone; and, almost on 
the opposite side of that part of the basin, on the north-east of 
the Leicestershire coal-field, the denudation extended down to 
the level of the Millstone Grit. Even if the denudation was not 
as great under all the Red ground of the basin lying between 
these two areas, the presence of undenuded Coal-measures in 
mass was, to say the least of it, doubtful. Again, the influence 
of the Pennine anticline was felt even in the north-eastern area 
of Cannock Chase, where the Millstone Grit laid at no great 
-distance below the surface, a fact pointing in the same direction. 
Although east of that area, the great eastern boundary-fault 
might again bring down the productive Coal-measures for a 
-certain distance under the Red rocks, the Carboniferous rocks 
would naturally retain their general rise towards the Pennine 
anticline, and a broad spread of barren ground might therefore 
be found under the Red rocks of what had been called the Mel- 
bourne-Derby ridge. 

The downward workable limit of 4,000 feet, referred to by 
Prof. R. A. S. Redmayne, was not a limit set by geologists, but 
that accepted by the last two Royal Coal Commissions. It was 
pleasant to be assiued that mining engineers had already ex- 
"Ceeded it successfully and profitably, and that consequently all 
the buried coal-fields might in time be worked. In the mean- 
time, however, Midland engineers could afford to be patient. 
Within the last thirty years, about 500 square miles of hidden 
<!Otil-field had been added to the productive areas in Nottingham- 
shire within that depth, the extent of the Warwickshire coal- 
field had been doubled, and in the same way as the Birmingham 
basin was opened out more than thirty years ago, by the late Mr. 
Henry Johnson's successful sinking of the shaft at Sand well 
Park, the Wolverhampton basin had now been opened out by 
Mr. John Hughes' successful sinking of shafts at Baggeridge 
Wood. 



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MONKWEARMOUTH COLLIEEY. 275 



THE NORTH OF ENGLAND INSTITUTE OF MINING 
AND MECHANICAL ENGINEERS. 



EXCURSION MEETING, 
Hbld at Sunpebland, June 6th, 1907. 



C PIT, MONKWEARMOUTH. 

The freezing method of sinking the new or C pit has been 
adopted, so as to avoid any chance of disturbing the A and B 
pits, at the adjoining Wearmouth Colliery, which have been in 
operation for seventy years. These pits are sunk to the Hutton 
seam, at a depth of 1,723 feet; and the new or C pit will be 
sunk to the Harvey seam, at a depth of 1,902 feet. The C pit, 
18 feet in diameter, is now sunk to a depth of 117 feet; but 
sinking operations have been suspended until the strata are 
frozen. For this purpose, 28 holes, 360 feet deep, have been bored 
round the circumference of the shaft, in a circle, 28 feet in dia- 
meter — ^three boring-machines, three steam-winches, and three 
steam-pumps being employed. Boring commenced on October 
8th, 1906, and was completed on March 15th, 1907: the total 
boring of 9,726 feet being thus completed in 128 days, or an 
average of 26 feet per day. 

Hollow rods, 2 inches in diameter and in 16 feet lengths, 
were employed, the weigh1>-rod being 16 cwts. The chisels varied 
from 7 inches to 12J inches in diameter, and weighed from i 
cwt. to 1^ cwts. The steam-pumps forced 4,000 gallons of water 
through each set of boring-rods per hour, the pressure at the 
pumps being 76 pounds per square inch. As an example of the 
speed of boring, one hole was bored 100 feet by means of chisels, 
12^ inches in diameter, and the hole was lined with tubes 11 
inches in diameter; it was then bored 90 feet deeper with chisels 
lOJ inches in diameter, and lined to this depth with tubes 9J 
inches in diameter; and the remaining 170 feet were bored with 
chisels 7J inches in diajneter, and the full depth was lined with 
tubes 6J inches in diameter, the total time occupied being 10 



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276 MONKWEAEMOUTH COLLIEBY. 

days. Each freezing-pipe comprises an upper tube, 240 feet long' 
and 5 inches in diameter; an expansion-piece; and the lower 
tube, 4 inches in diameter and 120 feet long : the double nipple 
being placed at a depth of 75 feet.* The central pipe, 1 inch in 
diameter, delivers the brine 3 feet above the bottom of the 
freezing-pipe. 

The refrigerating agent is anhydrous ammonia, and the brine 
is a 28-per-cont. solution of chloride of magnesium. Freezing 
commenced on April 10th, 1907. On June 6th, 1907, the tem- 
perature of the brine entering the pit was 2° Fahr. ( — 16'6^ 
Cent.), and returning from the pit, 9'50 Fahr. (- 12*50 Cent.). 
The cooling water entered the condensers at a temperature of 
54-60 Fahr. (1250 Cent.), and left at 61-70 Fahr. (IQ'b^ Cent.). 
The circulation of brine is about 150 gallons per minute, and the 
quantity of cooling water is approximately 200 gallons per 
minute. The pressure of the ammonia in the condensers is 9*& 
atmospheres, and in the refrigerators, 06 atmosphere. 



Trans, Inst, M, E,, 1906, vol. xxxii., page 576, plate zxviii., fig. 8. 



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DISCUSSION — ^NEW APPAKATTTS FOB EESCUE-WOEK IN MINES. 277 



MANCHESTER GEOLOGICAL AND MINING SOCIETY. 



GENERAL MEETING, 

Held is the Booms of the Society, Qtteen's Chambers, 

5, John Dalton Stbeet, Manchesteb, 

March 12th, 1907. 



Mr. CHARLES PILKINGTON, President, in the Chair. 



The following gentlemen were elected, haying been previously 
nominated: — 

Members-— 
Mr. Tom Stone, Mining Engineer, The Collieries, Garswood, near Wigan. 
Mr. Percy Hottston Swann Watson, Mining Engineer, 11, Trafalgar Square, 
Aahton-nnder-Lyne. 

Associate — 
Mr. John Galliitord, Colliery Manager, 479, Edge Lane, Droylsden. 

Student— 
Mr. H. Harorbaves Bolton, Jun., High Brake, Accrington. 



DISCUSSION OF MR. W. E. GABFORTH'S PAPER ON " A 
NEW APPARATUS FOR RESCUE.WORK IN MINES."* 

The Peesident (Mr. Charles Pilkington) said that the com- 
mittee, entrusted with the work of fitting up a station, near 
Tyldesley, for rescue-apparatus and for te^aching men how to use 
it, would start operations at once, and he hoped that six months 
hence there would be a place connected with the collieries of 
the district, where mining engineers and others could see rescue- 
apparatus at work and be trained in its use, or to which they 
could send their men to be trained. 

Mr. W. E. Gaeforth gave a demonstration of the working 
of the Weg apparatus. He would have preferred that the 
members had attended at Altofts to see the apparatus in use in 

• Tran». Inst. M. E., 1906, vol. xxxi., page 626 ; and vol. xxxiiL, page 180. 



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278 DISCUSSION — NEW APPABATUS FOR BESCUE-WORK IN MINES. 

the experimental gallery, under conditions which approximated 
as nearly as possible to those found in a mine after an explo- 
sion — as regarded damaged roadways, contracted passages and a 
noxious atmosphere. He had been engaged on the work of the 
life-saving apparatus for many years, and still considered that it 
could be improved. The supply of oxygen was sufficient for 2i 
hours, if the wearer were undergoing exertion, or enough for 6 
hours when the wearer was resting. The purifier contained about 
2 J pounds of caustic potash and caustic soda, which absorbed the 
carbon dioxide given ofE by the person wearing the apparatus. 
The apparatus had been made entirely at the colliery, but when 
it was put into the hands of a surgical-instrument maker he 
apprehended that the weight, at present 30 pounds, would be 
materially reduced. The apparatus did not interfere with the 
hearing of the wearer, and the goggles over the eyes could be 
removed (when advisable) without interfering with the other parts 
of the apparatus. As only a small portion of the head was 
covered, perspiration was as far as possible unchecked. 

Mr. Joseph Dickinson said that had Mr. Garforth carried 
his history of rescue-appliances 13 years prior to Sir Henry 
T. De la Beche and Dr. Lyon Playf air's invention, it would 
have comprized one on a similar basis for which 50 guineas and 
a silver medal was presented by the Society of Arts and the 
Royal bounty of £100 by King George IV.* The inventor 
was Mr. John Roberts (of XJpton-and-Roberts safety-lamp fame). 
The apx>aratus consisted of a mask, with goggles and inhaling 
arrangements through the interstices of a sponge immersed in 
varied saturated solutions of lime-water, chloride of lime, caustic 
soda, and sometimes pure water, according to the impurity likely 
to be met with. The expired air was not passed through the 
inhalator. 

Personally, the only breathing-appliance used by himself 
(Mr. Dickinson) on many explorations in foul air was the 1846 
bag of Glauber salts and lime. The mine was on fire, follow- 
ing an explosion in 1851, and Mr. Goldsworthy Gurney's treat- 
ment with the fumes from burning coke, salt, and sulphur had 

* ** ApparatuB to enable Persons to breathe in Thick Smoke, or in Air 
loaded with SuflFocatinff Vapours," by Mr. John Roberts, Transactions of the 
Society of Arts y 1825, vol. xliii., page 26 and plate L ; and Report from the Select 
Committee on Accidents in Mines, 1835, page 262. 



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DISCUSSION NEW APPAKATUS FOR RESCUE-WOEK IN MINES. 279- 

failed to extinguish the conflagration. The bags with the mix- 
ture were used for some hours, most of the explorers being sick ; 
and eventually the bags were discarded, and the fire was. 
approached in the old-fashioned way. 

E/escue-apparatus were now available of better form, and 
possibly some such might have saved some time ; but the 
saving would probably have been less than some persons might 
suppose. On such occasions, when survivors might possibly 
be rescued or valuable property saved, advances were made which 
under ordinary circumstances would be inexcusable. Dormant 
side-accumulations of foul air were then passed by, and left for 
future clearance. Exploration also followed underneath smoke 
and gas to close a hole in a blown-out stopping, and close touch 
was kept with the advancing air-column. In front of this, among 
debris, it would often be imprudent for apparatus-men to advance 
far. The common tests for gas — elongated flame and blue cap 
for fire-damp, dulled flame or extinction for black-damp, sensitive 
creepings for after-damp and white-damp— did not delay much, 
and with practice and care were reliable. The good results 
occurring from the lessening number of fire-damp explosions 
were it seemed so diminishing opportunities for re-entering that 
special education w:as now suggested ; consisting of the establish- 
ment of central training-stations with rescue-apparatus and a 
practi sing-gallery, which deserved favourable consideration. 

Mr. "W. E. Garforth pointed out that the apparatus would 
be considerably lightened if it were charged to last a man for 
only an hour. He asked Mr. Dickinson to say, from his un- 
equalled experience in rescue-work, if at times he had not found 
it of the utmost advantage for a man to be able to get as soon 
as possible into a pit when an explosion had occurred in order to 
ascertain the state of affairs underground. He did not hesitate 
to say that five men, who had been trained in the gallery in 
the use of this apparatus, could go into the most noxious atmo- 
sphere, and give relief to men who might be suffering. He held 
that if they could only save one life, it was worth all the trouble 
that he had taken in perfecting the Weg apparatus. With this 
apparatus a man would also be able to travel a certain distance, 
in order to ascertain if any part of the mine was on fire. On the 
occasion of an explosion at Altofts colliery, a fortnight was lost 



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^80 DISCUSSION — NEW APPARATUS FOR RESCUE-WOEK IN MINES. 

'before they were able to reach a certain point where a fire was 
discovered ; but with this apparatus they might have discovered 
the fire on the second day, instead of suffering great risks and 
anxiety actually incurred. 

The President (Mr. Charles Pilkington) said that he was in 
favour of rescue-apparatus being provided, but there was a diffi- 
■culty in the matter of weight. Thirty pounds was a great 
weight for a man to carry a long distance. As to the general 
utility of rescue-appliances, it had been stated that no lives 
were saved through their instrumentality after the Courrieres 
explosion ; but it must be remembered that there were no appar- 
atus in the district at the time of the disaster. 

Mr. John Gerrard said that occasionally the need arose, in 
exploring mines after explosions and in connection with fires, 
to use all the appliances that science and experience had sug- 
gested : thus mice and birds, by reason of their greater suscepti- 
bility to carbon monoxide, gave early intimation of its presence. 
The statement that rescue-apparatus failed at the Courrieres 
mines, he emphatically declared, was most unfair, as the rescue- 
apparatus had not a chance to save life. It was perfectly true that 
men came out of the pit alive after Mr. G. A. Meyer arrived at 
the Courrieres collieries, but everybody at that time firmly be- 
lieved that there was not a living man in the pit, and everybody 
acted on that assumption. He (Mr. Gerrard) thought that Mr. 
Garforth was deserving of all praise for his persistent efforts 
to perfect this apparatus. Fortunately, Lancashire had been 
spared disastrous explosions of recent years ; but not infrequently 
trouble had arisen through fires which might much sooner 
have been extinguished, if such an apparatus as that which Mr. 
Garforth had designed had been available for use. Life also 
would have been saved. In connection with fires, there was, 
he was persuaded, a big field for the use of this kind of appar- 
atus in Lancashire. He was hoping that before long they 
would have a rescue-station in Lancashire, where men could 
accustom themselves to the use of these appliances. He (Mr. 
GeiTard) raised the question of what could be done in the 
event of a man equipped for rescue-purposes passing through 
foul air to a place where the air was tolerable and finding men 



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DISCUSSION — ^NEW APPAEATttS FOB. JEtBSCUE-WORK IN MINES. 281 

alive there. Mr. G. A. Meyer had made a supplementary appar- 
atus to bring out men. in such cases. He moved that the best 
thanks of the members be given to Mr. Garforth. 

Mr. John Gallifoed seconded the motion, which was 
cordially approved. 



Mr. John Galufom> read a paper on '^ A New Eeflector for 
Safety-lamps." The reflector, made of aluminium, 5 inches in 
diameter, can be fitted, above or below the standards or poles 
protecting the glass of a Clanny type of safety-lamp; by means 
of a spring clip or a bayonet joint. 



TOL. XXX1II.-1906.W07. 



22 



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282 TKANSACnONS. 



MANCHESTER GEOLOGICAL AND MINING SOCIETY. 



GENERAL MEETING, 

Held in the Booms of the Society, Qitebn's Ghambbbs, 

5, JoBK Dalton Street, Mawohesteb, 

April 9th, 1907. 



Mr. CHARLES PILIUINGTON, President, in the Chair. 



The following gentlemen were elected, having been previously 
nominated : — 

Member— 
Mr. William Oldfield, Miniog Engineer, West View, Minsterley, Shropshire, 

Associate^ 
Mr. George Reynolds Wynne, Hope Cottage, Tarvin Road, Cheeter. 



Mr. W. H. Coleman read the following paper on " The Cook 
Calorimetric Bomb " : — 



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THE CX)OK CALOBIMETBIC BOMB. 28S 



THE COOK CALOBIMETBIC BOMB. 



By W. H. COLEMAN. 



Introdtietion. — In bringing this new pattern of bomb calori- 
meter before your notice^ it is necessary to preface the descrip- 
tion with a few words on fuel-valuation. 

This subject may be divided into three heads : — (1) Sampling 
the fuel ; (2) determining its calorific value ; and (3) comparing 
different fuels, so as to find out which will serve the purpose in 
hand most economically. 

(1) The Sample, — The chief difficulty in the way of deter- 
mining the calorific value of a fuel is the fact that it is not at all 
easy to obtain an average sample. Unless the sample is what it 
professes to be, that is, of the same composition as that of the 
whole bulk of the fuel under examination, it is useless to waste 
time and money in making elaborate calorimetric determina- 
tions. If the sample is to represent a seam of coal, several 
freshly hand-cut portions should be taken from different parts 
of the seam ; taking care that a strip is cut from a fresh face from 
top to bottom of the seam and that it contains everything, 
whether coal or dross, that would be sent to the surface as coal, 
and nothing else. 

If the sample represents a delivery of a particular quality 
of coal, then a truck or a cart-load should be selected at random 
from a number of freshly-filled trucks or carts. Special care 
should be taken that the loads are average ordinary loads, which 
have been filled for delivery, without any attempt to pick the 
quality. The whole load should be tipped, well mixed, and quar- 
tered down until a sample of about 1 hundredweight is obtained. 
Great care must be taken that this contains the right proportions 
of large, small and fine coal. The sample should then be either 
put through a stone-breaker, or ground roughly in a mortar-mill. 
It should then be again quartered, until a sample weighing 2 
or 3 pounds is obtained. This must then be ground in a suit- 
able mill to a moderately fine granular powder. It is necessary > 
when determining the moisture in a coal, to be sure that it is 



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284 



THE COOK CALOBIMETRIC BOMB. 



not too finely ground, and it should be bottled at once. The 
sampling, grinding, etc., should be quickly done, so that the 
coal may not lose moisture. 

(2) The Calorific Value. — Three ways offer themselves for 
determining the calorific value of a fuel : — (l)An ultimate analysis 
of the coal may be made, and its theoretical calorific value 
may be obtained by calculation. This method, though accurate, 
takes a considerable time and requires the services of an expert 




Fill. 1.— Thk Cook Calobimetbic Bomb. 

chemist. (2) The moisture, ash, volatile matter and fixed car- 
bon may be estimated, and the calorific value calculated from one 
of the numerous formalee given by different authorities. This 
method is simple, and can be carried out by an average intelli- 
gent laboratory-assistant; but the results, though useful in 
checking deliveries, the calorific value of which has been deter- 
mined by the first method from a previous sample-delivery, are 
not sufficiently accurate to discriminate between several different 
qualities of coal. (3) The actual calorific value may be deter- 
mined by means of a calorimeter. 



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THE COOK CALORIMETRIC BOMB. 



285 



In principle, all calorimeters depend upon burning a weighed 
quantity of coal and observing the rise in temperature imparted 
to a known quantity of water by the heat given out during the 
complete combustion of the fuel. Several forms of calorimeters 
have been proposed. 

(a) LemS'Thompson Calorimeter, — In this instrument, the 
weighed sample of coal is mixed with potassium chlorate or some 
other oxygen-carrying body and burnt in a bell- jar immersed in 
water contained in the calorimeter. . -^ 

The products of combustion bubble up- [ J ^ j*;^ ^^ H 
wards through the water, to which they j |_ 

communicate their heat. I 



1^ 



(6) Williani'Thomson, Fischer and 
Darling Calorimeters, — These calorime- 
ters are all modifications of a similar 
principle. The coal is burnt in a 
crucible placed in a bell- jar immfersed 
in water in the calorimeter. It is not 
mixed with any oxygen-carrying ma- 
terial, but a stream of oxygen is caused 
to pass into the bell- jar. The products 
of combustion escape, as in the first- 
mentioned apparatus. In the Fischer 
calorimeter, the gases pass through a 
special chamber. 

(c) Parr Calorimeter, — In this ap- 
paratus, the weighed coal is mixed with 
sodium peroxide, which serves to supply 
the oxygen necessary for combustion, 
and the caustic soda produced absorbs 
and combines with the carbon dioxide 
given off by the burning fuel. The mix- 
ture is placed in a closed metal chamber 
immersed in the water of the calorimeter, and ignited. 



r 




Fig. 2.— The Cook Bomb. 
ScALB, 2 Inches to 1 Inch. 



(d) Berthelot'Mahler Bomb. — In the new modification of this 
instrument (fig. 1), the weighed sample of coal is placed in a 
platinum crucible, G, which is then placed on the wire support- 



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286 THE COOK CALORIMETBIC BOMB. 

ing ring, H (fig. 2). In order to ignite the coal, a fine platinum 
wire, I, is connected to the supporting ring, H, and to the other 
wire, J, depending from the cover. The latter, carrying the 
crucible, is gently lowered into the bomb and screwed up tightly. 
Oxygen, under pressure, is then admitted to the bomb until the 
gauge registers a pressure of about 21 atmospheres. The valve, 
A, is then shut, and the oxygen-cylinder is disconnected. The 
bomb is then carefully lowered into the copper calorimeter vessel, 
into which about 2 litres of water, slightly below the temperature 
of the room, is poured; and the wires of the battery are con- 
nected to the bomb, at E and K, the circuit being open. This 
vessel stands in another double-walled copper vessel filled with 
water at the room-temperature, and surrounded by felt to prevent 
loss or gain of heat from surrounding objects. 

The agitator is set to work, and the rise in temperature of 
the water is observed ; and, when this is constant, the circuit is 
closed, and the coal is burnt. The temperature of the water 
rises, and the maximum point is noted. Then the increase in 
the temperature of the water in Centigrade degrees, multiplied 
by the weight of the water and the water-equivalent of the appar- 
atus, gives the number of calories evolved by the combustion 
of the weight of coal taken. If 1 gramme had been taken, then 
this number represents the calorific value in calories ; and if not, 
then the figure is divided by the weight of coal taken. The 
calories multiplied by 1*8 give the British thermal units per 
pound of coal. The evaporative power of the fuel from and at 
212^ Fahr. is obtained by dividing the calorific value, expressed 
in British thermal units per pound by the number, 966, repre- 
senting the latent heat of vaporization of water in Fahrenheit 
units. Several forms of this calorimeter have been proposed ; — 
The original Mahler bomb; the Bryan-Donkin bomb; and the 
Cook-Berthelot-Mahler calorimetric bomb shown in figs. 1 and 2. 

This latter form has several improvements, and has been found 
very satisfactory in use. The chief improvements are the gas- 
valve, A, and the gas-inlet, B. In older forms of the instru- 
ment, the gas entered at the top instead of at the side, and the 
valve had to be slightly loosened to disconnect the copper pres- 
sure-tube. Other minor advantages are the following: — The 
gas-inlet valve does not easily get out of order. The stirring 
arrangements are very simple. The connections have coned 



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THE COOK CALOKIMETBIC BOMB. 287 

joints, C, and do not require washers. The insolation, D, of 
the ping, E, is protected from injury by high temperature at the 
moment of explosion, by a quartz plate, F. Care must be taken 
that the apparatus is tight ; and, to ensure this, the lead-washer 
should be examined to see that it is not burred. 

Several points require a little attention : the coal should be 
dried at a temperature of about 110 Cent. (230° Fahr.) ; and 
should be finely powdered, and then made into briquettes with 
the small briquetting machine. 

The water-equivalent of the apparatus is best found by deter- 
mining the calorific value of pure cellulose (4,200 calories) or 
naphthaline (9,692 calories). A correction for cooling ought to 
be made for very accurate experiments.* If, however, the water- 
equivalent of the apparatus is determined by burning naphtha- 
line, and such a quantity is used as to give about the same rise of 
temperature as the weight of coal taken, this correction may be 
neglected if the determination is only wanted to be within ^ or 
1 per cent, of the truth. 

It may also be advisable to correct the results for the nitric 
acid and sulphuric acid formed. This can be done by washing 
out the bomb after the experiment, and estimating the quantities 
of nitric acid and sulphuric acid formed. 

The room, in which calorimeter-determinations are made, 
should have a temperature of about 60° Fahr., and the water should 
be about 2^ Cent. (4° Fahr.) below the temperature of the room. 

Of course, a calorimetric determination does not tell all there 
is to be known about the suitability of a coal for any particular 
purpose. The length of flame, the quality of the ash (whether 
easily fusible or not), and other factors must be taken into con- 
sideration ; but, given several samples of coal, all of which are 
otherwise suitable for the intended use, the most economical coal 
can be selected by the calorimeter. If, from the result of the 
determination, the number of calories obtained for any given 
sum of money be calculated, it is easy to pick out the most 
economical fuel. 

* This is made by obaervinc the rate of the riBe of temperature that takes 
place when the bomb is placed in the calorimeter and before the charge is fired, and 
.also the rate of the fall of temperature daring a similar period of time after the 
maximum temperature has been reached. From these observations, the loss by 
radiation daring the experiment can be calculated and a correction applied. 



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288 DISCUSSION — ^THE COOK CALORIMETBIC BOHB. 

At the present day, when every little detail has to be con- 
sidered in order to make a profit, there is no doubt that the coal 
which can be guaranteed to give the best result for the money 
will find the readiest sale. 

Anyone who is desirous of going further into the question 
of valuing fuel may refer to the excellent paper by Mr. J. B. C. 
Kershaw.* 



The President (Mr. Charles Pilkington) thought that the 
instrument was very valuable, and suggested that, when a coal- 
owner wished to ascertain the true value of his coal-seam, or of a 
particular X)ortion of a seam, samples taken from all points of 
the seam should be duly tested in the calorimeter by a competent 
person. 

Mr. Gqleman said that a sample of 7 or 8 pounds of coal 
should be sent, broken into nuts, and then the final grinding 
could be done quickly. 

The President asked what allowance was made for ash. 

Mr. Coleman said that no allowance was made for ash in the 
coal, as it would have the same influence in the calorimeter as 
in the furnace. The coal was burnt with pure oxygen. An 
electric current with a pressure of 12 to 20 volts would suffice 
to ignite the charge. 

The President said that the calorimetric bomb was valuable, 
but he thought that it was more for use in the laboratory than at* 
a colliery. 

Mr. Sydney A. Smith said that the calorific value of a coal 
could be ascertained by this instrument, but it did not indicate 
the value of the coal as a fuel suitable for a particular purpose ; 
and much depended on the rate of combustion. In a recent 
case, there was a dispute about a shipment of coal. The calorific 
value was excellent, but it could not be burnt, except at a very 
slow rate, in the ordinary grates of water-tube boilers, without 
forced draught. In ascertaining the value of coal as fuel, that 

* ** Fuel Analysis for Steam Users," by Mr. J. B. C. Kershaw, The Engineer^ 
1906, vol. cii., pages 314 and 337. 



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DISCUSSION — THE OODK CADLOHIMETRIC BOMB. 28ft: 

point must be considered, because the value of a coal for a 
particular purpose depended on the rate of combustion. Some 
coals burnt rapidly, others burned slowly, and yet all might 
have the same calorific value. 

Mr. Coleman admitted that even when the calorific value of a 
coal had been determined, the question as to the coal's suitability 
for a particular purpose was not settled. But given several 
coals, at different prices, that were suitable as regarded their 
burning qualities, the calorimetric bomb would indicate the one 
that produced the most heat for the least money. The question 
of ash was of the utmost importance in some cases. 

A vote of thanks was accorded to Mr. Coleman for hi» 
interesting jniper. 



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290 TBANSACnONS. 



MANCHESTER GEOLOGICAL AND MINING SOCIETY. 



GENERAL MEETING, 

Held in thb Rooms of thk Sociktt, Queen's Chambeil«, 

5, John Daltov Strut, Manchbstkb, 

May 14th, 1907. 



Mr. CHARLES PILKINGTON, Prkidsnt, in the Chair. 



The following gentlemen were elected, having been previously 
nominated: — 

Members-- 
Mr. Alfred Ackroyd, EUerslie, Victorift Crescent, Ecoles. 
Mr. Hugh Frank Taylor, Mechanical Engineer, Sandy Croft, near Chester. 
Mr. Thomas Williams, Mining Engineer, 5, Westboume Grove, Hexham. 



Mr. Frederick J. Thompson read the following paper on 
** The Rock-salt Deposits at Preesall, Fleetwood, and the Mining 
Operations Therein " : — 



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EOCK-SALT DEPOSITS AT PEEESALL. 291 



THE ROCK-SALT DEPOSITS AT PREESALL, FLEET- 
WOOD, AND THE MINING OPERATIONS THEREIN. 



By FREDK. J. THOMPSON. 



Introdiiction. — This paper is divided into four parts, com- 
prizing : — <1) Tlie history and the geology of the rock-salt 
deposit at Preesall; (2) the method of sinking shafts for 
Tock-salt; (3) the methods of mining rock-salt; and (4) a 
description of the Preesall salt-mine worked by the United 
Alkali Company, Limited. 

(1) History and Geology. — ^The earliest record of any under- 
ground exploration, near Fleetwood, is that of a bore-hole, A 
■(fig. 2, plate X.),* put down by the Royal Engineera in 18G0 in 
search of water for the troops then stationed at Fleetwood, the 
iown at that time being entirely dependent on surface-wells for 
its water-supply. This bore-hole was carried to a depth of 559 
feet, the whole of the distance being bored in Keuper marls — 
with the exception of a few feet, near the surface, in the usual 
surface-drift ; but no water waa found. 

In 1872, the district on the Preesall side of the river Wyi*e 
was mapped out by a syndicate, with the intention of putting 
down twenty bore-holes in various places in search of iron-ore, 
as it was thought possible that such might exist on the south 
side of Morecambe bay, as well as at Barrow-in-Furness and 
other places on the north side (fig. 1, plate x.). The site ot 
-each of these twenty bore-holes was fixed^ and some of them were 
bored simultaneously, but the only available records are those 
of Nos. 2, 8, 9 and 17 (fig. 2, plate x.)- Rock-salt was struck 
in No. 2 bore-hole in 1872, and signs of rock-salt in two of the 
others; and there is no doubt that the discovery of rock-salt 
prevented the completion of the original design of twenty bore- 
holes. 

In 1875, No. 17 bore-hole was put down about | mile to the 
jiorih-east of No. 2 bore-hole in which rock-salt had been stinick, 



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292 ROCK-SALT DEPOSITS AT PBEESALL. 

and red sandstone was found at a depth of 45 feet from the sur- 
face. The boring was continued to a total depth of 664 feet from 
the surface, and indicated the existence of an enormous supply 
of fresh water. The map (fig. 1, plate x.) shows the relation 
of Fleetwood on the south side of Morecambe bay to Barrow-in- 
Furness on the north side. All previous geological surveys had 
indicated that the red-sandstone fault was 8 miles eastward of 
the site of No. 17 bore-hole, which had struck sandstone at 
Preesall. The author, in 1906, constructed a geological section 
running east-and-west through the rock-salt deposit, and the 
late Mr. C. E. de Bance expressed the opinion that it was- 
substantially correct. A reproduction of this section is shown, 
in fig. 3 (plate x.). 

Nothing further was done in the development of the minerals, 
as the state of the salt-trade did not warrant such, except that m 
1885, a shaft around No. 2 bore-hole, which had previously been 
sunk from the surface into the rock-head, was carried still lower 
into the rock-salt bed until the bottom was reached. This shaft 
indicated a total thickness of 340 feet of rock-salt stratified in 
several layers of very good and some of inferior rock-salt and 
marl. 

The general theory amongst geologists as to the origin of the 
various rock-salt deposits found in this country is that, at some 
remote period in the world's history, considerable quantities of 
sea-water had, owing to changes in the earth's surface, been, 
separated from the main body of the sea; and that solar evapora- 
tion concentrated such bodies of sea-water until salt was- 
deposited. This flooding of the same area, happening again and 
again, would account for the deposits of marl and inferior rock- 
salt, which originally would be deposited as mud and salt. It 
is not the author's intention to express any opinion as to this, 
theory ; but it is obvious to anyone that salt could not have been 
in solution in sea^water, unless it had been dissolved from the 
solid mass in some previous formation. 

Nothing was done in the way of serious development until 
1889, when the reconstructed Fleetwood Salt Company, Limited, 
took over the undertaking, and the author was engaged by them 
to take charge of the development of the salt-beds. The old 
shaft previously mentioned was converted into a shaft for pump- 
ing brine, the small amount of natural brine found in it on the 



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BOCK-SALT DEPOSITS AT FBEESALL. 293 

rock-head being augmented by putting water down bore-holes, 
which were bored down to the rock-head at a short distance away 
from the shaft. Salt-works for the evaporation of the brine 
were erected on the Fleetwood side of the river Wyre and were 
connected to the brine-pumping station by a line of pipes, which 
were laid across the estuary of the Wyre (fig. 2, plate x.). It 
is not the author's intention to deal with the question of brine- 
pumping or salt-making, except to state that both operations 
have attained considerable proportions, especially since the erec- 
tion of the Ammonia-soda works at Fleetwood by the United 
Alkali Company, Limited, who acquired the whole of the Fleet- 
wood imdertaking from the Fleetwood Salt Company, Limited, 
in 1890. It may be stated at this point that salt was required 
by the company as a raw material in the manufacture of various 
products involving the use of chlorine or sodium. 

(2) Sinking Shafts. — ^In 1893, the United Alkali Company, 
Limited, decided to sink sha'fts for the purpose of mining rock- 
salt in a dry state, and they were commenced in that year. 
In sinking shafts for the purpose of mining rock-salt it is neces- 
sary to ensure the absolute exclusion of all water or moisture ; 
as, rock-salt being extremely soluble, great havoc would be 
caused if water were allowed to enter any salt-mine. This must 
be effected, before the rock-salt bed is entered, in carrying down 
the shafts. 

The first stratum passed through was the boulder-clay over- 
lying the Keuper marls, and this was gone through by two tim- 
bered shafts, each 7^ feet square. A considerable amount of 
water was found in various places in sand-beds in the boulder- 
clay, besides enormous boulders, which occupied in some places 
the whole area of the shaft in sinking, and had to be blasted 
before they could be raised to the surface. The boulders were 
mainly of limestone, and many of them showed extraordinarily 
clear ice-markings of the glacial period. 

The Keuper marls were reached with both shafts, which were 
continued until the marls were found in such a condition as to 
afford a safe foundation ; at these points in each shaft, a brick- 
work foundation was built in with blue bricks and Portland 
cement; and from this foundation, iron tubbing was carried 
to the surface. This tubbing consisted of cast-iron socket-and- 



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294 BOCK-SALT DEPOSITS AT PBEESALL. 

spigot pipes, 6 feet in diameter. The space between, the back of 
these tubes and the timbering of the shaft was filled with clay- 
puddle, and the absolute exclusion of the water was thus effected. 
The shafts were afterwards continued downwards through the 
Keuper marls to the rock-salt bed, and were stopped, for the 
time being, in a good bed of rock-salt, about 450 feet from the 
surface. 

« 

(3) Mining, — ^As an interval of 50 years had elapsed, prior to 
this, since any rock-salt mine had been opened out, the author 
had no previous personal experience to guide him as to the best 
method of opening out a mine in the shortest possible time. A 
rock-salt mine is different from most mines, owing to the fact 
that it does not consist of a series of passages or ways ; but it is 
only one large excavation or cavern hewn out of the solid rock- 
salt, with solid masses of rock-salt left in at various places for 
the purpose of supporting the roof /fig. 4, plate x.). The usual 
way of opening out such a mine had been to commence enlarg- 
ing the two shafts, around their bottoms, until they met and 
formed one excavation, and afterwards this operation was con- 
tinued all around. This meant that for some time, owing to the 
smallness of the excavation, very few men could be put into the 
work, as blasting operations would render the presence of a 
large number of men undesirable, because of the danger. 

It was ultimately decided to employ a compressed-air tunnel- 
ling-machine, to drive headings in various directions into the 
rock-salt at as rapid a rate as possible. This machine, supplied 
with air from a compressor stationed on the surface, drove head- 
ings b\ feet in diameter at the rate of 360 feet per week. A 
heading was driven first from one shaft to the other in an 
easterly direction and continued a considerable distance in that 
direction, and afterwards a heculing was driven in a westerly 
direction ; and, while so driving in this westerly direction, men 
were put into the eastern heading to widen it out northward and 
southward. Another heading was driven by the machine in a 
northerly direction and other men put into the western heading, 
so that in a very short time there was a considerable area of 
excavation, 6 feet in height. The widening out of the headings 
was done by rotary undercutting machines, worked by com- 
pressed air, and these machines have been retained until this 



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KOCK-SAI.T DEPOSITS AT FREESALL. 295 

day, four being now at work. The bed of rock-salt that is being 
mined is about 40 feet thick, and it dips in a north-westerly 
direction at the rate of 1 in 3^. 

The rock-salt is mined by making a " roofing," A, 6 feet in 
height at the top of the bed; and the roof thereof afterwards 
forms the ceiling of the mine (fig. 6, plate x.). The roofing 
is done by machine-undercutting, in lengths of 105 feet — ^the 
distance between each pillar, the pillars being 60 feet square. 
Bock-salt is much harder to mine than coal, and an ordinary 
coal-undercutter will not touch it. The special undercutting 
machines made for this purpose, undercut to a depth of 2^ feet 
only. 

The roofing lays bare the whole of the lower part of the bed^ 
say, 34 feet thick, and this is worked by blasting from the face 
as in open quarry operations. Black gunjwwder, in compressed 
cartridges, is used for the purpose of blasting all over the mine. 
The rock-salt, after blasting, is slid down the face to the floor of 
the mine where it is filled into hoppets, B, trammed to the shafts 
and wound to the surface in the usual way (fig. 5, plate x.). 

Members who have had any experience of the ordinary rotary 
undercutter, will no doubt be aware that, in undercutting from 
one face to another, the two ends of the cut cannot be touched^ 
but have to be got out by other means, as the rotary under- 
cutter will not start at, or finish right to the end of the cut. 
This necessitates getting out the two ends either in advance of 
the cut or after the cut has been made by the undercutter. In the 
case of rock-salt mines, it has been found easier to get out these 
ends after the long cut has been made; and, for this purpose, 
IngersoU-Sergeant coal-cutting or punching machines are used. 
These machines are also used in other parts of the mine, where 
the range of cutting is so short that it will not pay to run the 
rotary undercutter. 

It is in the direction of drilling holes for blasting that the 
most rapid strides have been made in advance of the old methods 
employed in Cheshire and elsewhere, and it has been the means 
of great economy over the original methods of drilling holes. 
The original method of drilling holes in rock-salt was by using 
a long bar of iron, steel-pointed at each end, as a jumping di-ill, 
worked by hand. By this means one man can drill a hole, 1^ 
inches in diameter and 5 feet deep, in about 45 minutes. The 



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'296 BOCK-SAKT DEPOSITS AT PBEESALL. 

author first introduced into salt-mines worm-drills, operated by 
ratohets, worked by hand, the Elliott drill being* the most suit- 
able for rock-salt mining owing to the fact that the pressure on 
the feed can be regulated by a friction-brake. This is especially 
necessary in rock-salt owing to its varying nature, several degrees 
of hardnees being gone through in a single hole. Later, com- 
pressed-air motors were applied to the end of the feed-screw of 
these drills, the result being eminently satisfactory, and, at the 
present time, practically the whole of the drilling in the mine is 
done by means of drills driven by compressed-air motors. It is 
now quite easy for one man to put in a hole 1^ inches in diameter 
and 6 feet deep in 5 minutes, by means of one of these motor- 
driven drills. 

(4) Description of Mine and Plant, — The total thickness of the 
rock-salt bed at the Preesall mines is approximately 380 feet; 
but^ as stated previously, although homogeneous, it contains 
strata of varying quality and only a portion of it is mined. 
There are two levels in the Preesall salt-mine: the floor of the 
upper mine being about 470 feet from the surface, and that of 
the lower mine 900 feet. In opening these mines, a thickness 
of about 40 feet was mined in the upper level ; but, some three 
years ago, the shafts were carried down to the bottom of the 
salt-bed, and it was found that a thickness of about 22 feet of 
rock-salt at the bottom was of very superior quality. At the 
present time, mining operations are confined to thicknesses of 
122 feet in the upper mine and of 22 feet in the lower mine. 

The same winding-engine is used for both mines, a larger 
drum and a longer rope being used for the bottom mine than 
those used for the upper mine, the difference in the weight of the 
load being made up by a balance-weight on the rope of the 
upper mine. Cages are not used in the shafts. There are two 
guide-ropes, EE, in each shaft, and guides, D, are attached 
thereto (fig. 6, plate x.). The rock-salt is loaded in the mine 
into large wooden hoppets, locally called " rock-salt tubs." These 
hoppets, placed on the frame of a bogie, are not attached to it 
in any way, and when fully loaded they contain about IJ tons 
of rock-salt. They are trucked to the shaft-bottom by the men 
who load them. The empty tub goes down the shaft and is 
placed on a bogie waiting to receive it, the three hanging chains. 



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BOCK-SALT DEPOSITS AT PSEESAIX. 297 

attached to it, are unhooked and the bogie and the empty tub 
are pushed away ; the bogie and the loaded tub are moved into 
the place of the empty tub, and the three chains are hooked and 
the loaded tub hoisted to the surface. 

There are two systems of signalling, one being electric and 
the other by an ordinary signal-line, pulled by hand, which 
actuates a hammer and gong on the surface. Similar return 
signals are also employed, the one system of signalling being 
simply a standby for the other in case of failure. 

The dip of the strata necessitates the use of several com- 
pressed-air haulage-engines in the mine. Air for driving the 
haulage-engines, the undercutting machines and the drills, is 
supplied from an air-compressor, fixed on the surface, capable of 
dealing with 2,250 cubic feet of free air per minute. The air 
has a pressure in the mine of about 70 pounds per square inch. 

The upper and lower mines are lighted by electricity ; Cooper- 
Hewitt mercury-vapour lamps have been found extremely 
effective for this purpose; while for general lighting, and in 
other places for local lighting, tantalum-lamps have now taken 
the place of ordinary, carbon-filament incandescent lamps. No 
gases of any description are encountered in the rock-salt beds, 
and natural ventilation is found to be all that is required, 
assisted by the exhaust-air from the various engines. 

The mine is capable of turning out 3,500 tons of rock-salt per 
week, containing an average of 96'5 per cent, of chloride of 
sodium. About one half of the present output is consumed at the 
various works of the United Alkali Company, Limited, at Widnes, 
St. Helens, Runcorn, Flint, Glasgow, Irvine and Bristol. This 
portion of the output is ground by specially designed machinery 
to a fine grain, and it has been the means of ousting higher- 
priced manufactured salt from the various chemical processes of 
the United Alkali Company, Limited. This grinding process is 
peculiar, inasmuch as it mechanically removes the marl-impuri- 
ties contained in rock-salt, these impurities going from the 
screens in the shape of tailings. The grinding machinery is 
capable of reducing 60 tons per hour to the grain of common 
white salt. 

The mine is situated about 1 mile from the estuary of the 
river Wyre at Fleetwood, and there is a railway of standard gauge 
to the Company's pier on the river Wyre, where vessels up to 
VOL. zzxiu.-iMe.uo7. 23 



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298 DISCUSSION — ^ROCK-SALT DEPOSITS AT PBEESAIX. 

1,500 tons burdea can be loaded. A large percentage of the 
output is shipped direct to the Continent. 

In conclusion, the author expresses his thanks to the direc- 
tors of the United Alkali Company, Limited, for permission to 
give the information respecting their operations contained in 
this paper. 

Specimens of rock-salt of various qualities and colour, and 
also of the Keuper marls, overlying the rock-salt, were produced 
for inspection. 



Prof. W. Boyd Dawkins moved that a vote of thanks be 
tendered to Mr. Thompson for his paper. 

Mr. Joseph Dickinson, in seconding the motion, said that 
Mr. Thompson's paper related to a branch of mining in which he 
(Mr. Dickinson) had been much interested, having in his time 
been in every rock-salt mine in England and Ireland. He had 
been several times in the first shaft sunk at Preesall, and had 
seen the development as now described. The paper gave the 
depth of the two workings in the mine, one under the other, and 
the distance between the supporting pillars, leaving members to 
infer from the section that a sufficient thickness of rock-salt was 
left for roof-strength between the pillars. The height of the 
workings was similar to that of many old mines, but it had been 
greatly exceeded in recent Irish mines, where the dip was about 
the same as at Preesall. Under-cutting or holing by machinery 
had during many years been successfully used in other rock-salt 
mines. He (Mr. Dickinson) was much impressed with the rapid 
rate at which the mine had recently been extended, and the in- 
crease of brine, by putting water down the bore-holes, from a 
trickle to a large quantity. The quickened opening was explained 
by the altered mode of driving out from the shafts, aided by com- 
pressed-air drilling-machines. In addition to these modifications^ 
the improved dressing apparatus had been mentioned. 

The motion was carried unanimously. 

Prof. W. Boyd Dawkixs (Manchester) said that he had been 
very much interested in hearing Mr. Thompson's account of the 



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Du-l 



Voi^XXXm^TiATE K. 




49a to 1 inch. 




VojlXXX. 

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DISCUSSION — ROCK-SALT DEPOSITS AT PBEESALL. 299 

occurrence of the red sandstone in the vicinity of the Preesall 
mine. Large quantities of water were always found in the red 
sandstone, where there was a fault, as in this case, with the red 
marl, which was practically impervious, on one side, and the red 
sandstone on the other. The discovery of rock-salt was extremely 
interesting to him, because it went to prove the existence of a 
salt-field under the sea, between the Isle of Man, and Preesall 
and Barrow in England, and Carrickfergus in Ireland. Some 
years ago he laid before the members an account of the discovery 
of rock-salt in Triassic strata in the boring at the Point of Ayr 
in the Isle of Man, and a thickness of over 70 feet of rock-salt 
was proved. The brine was now pumped and conveyed in pipes 
to Ramsey from the Point of Ayr, and the manufacture of salt, 
on a small scale, had been commenced. The rock-salt round 
the Irish Sea was of very great geological interest. He could 
not help thinking that in remote times there was a great salt- 
basin between the Isle of Man and the Lake country, analogous 
to the great salt-field of Cheshire. 

Mr. John Gerhard (H.M. Inspector of Mines) said that 
geologically it was extremely interesting to note that at Fleet- 
wood, near Barrow, also in the Isle of Man, and again on the 
north-eastern coast of Ireland, rock-salt had been proved. At 
Fleetwood, a bore-hole seeking iron-ore; at Barrow, in the Isle of 
Man, and at Carrickfergus, the bore-holes were in search of coal. 
The Preesall mine was probably the most productive salt-mine in 
this country, and having seen Mr. Thompson's work at the mine 
he could assure the members that the intelligence which Mr. 
Thompson had displayed in this paper was fully carried out in 
the practical work of the mine. He (Mr. Gerrard) had seen in both 
the upper and lower mines, a band of salt, very crystalline in 
appearance, several inches thick; the men stated that this 
guided them in working the salt; and he asked whether this 
band ran generally throughout the proved mine. He also asked 
whether it was a fact, where the very pure, very^ white rock-salt 
was found, that above or below it, the salt was very impure and 
mixed with marl. And, lastly, in giving the time occupied in 
drilling the holes by machine, did the author include the time 
vpccupied in fixing and taking down the machine. 

Mr. Thompson replied that the seam of crystalline salt was 



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800 DISCUSSION — ^ROCK-SAI.T DEPOSITS AT PREESALL. 

overlaid by 6 feet of rock-salt and underlaid by 16 feet or 16 feet 
of good rock-salt. Tliis seam was found in the upper as weU as 
in the lower mine, and indicated the direction of the dip. There 
was nothing like it found in Cheshire. An analysis of this seam 
showed that it did not vary from that of the other parts of the 
mine, except that it was uniformly of good quality and contained 
no marl, and was softer than the larger bed of rock-salt. It 
was more like g^t, although it was not in any way grritty, and 
the men called it the *' gritty seam." 

Mr. John Qebrabb asked whether Mr. Thompson had formed 
any theory as to these guiding crystalline bands and their rela^ 
tion to the seams around them. 

Mr. Thompson stated that he had not formed any theory as to 
the relation of the crystalline bands; but they were found in 
both the upper and the lower mines, and could be relied upon 
as guides in working the rock-salt. 

Mr. John Qerrabd said that he had been repeatedly asked by 
persons interested in brine and salt production why at Fleetwood 
so large an amount of rock-salt was mined, in addition to the 
pumping of a large quantity of brine. The mechanical arrange- 
ments worked admirably, and the rapid opening-out of the mine, 
under the conditions obtaining in this case, showed that colliery 
engineers had something to learn. It was an instance of the 
advantage of persistent effort in using machinery for opening 
out mines ; and he thought that Mr. Thompson would bear him 
out in saying that the first machine tried was not altogether a 
success, as it had to be altered and adapted to the conditions. 

Mr. H. Stanley Atheeton asked how it had come to pass 
that these salt-deposits were found so much below the present 
sea-level. He also asked whether in the working of rock-salt it 
was easier to cut in one direction than another. In other words, 
was it similar to working an anthracite-mine, where if the cut 
was made along the lines of crystallization the work was much 
easier, and there was an easier line of cleavage and a much 
better way of cutting. 

The President (Mr. Charles Pilkington) directed attention to 
the supporting shaft-pillars in the Preesall mine, being on a dif* 



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DISCUSSION — ^EOCK-SALT DEPOSITS AT PBEESALL. 801 

ferent scale from those deemed necessary in coal-mines. He was 
astonished at the rapid process of the tunnelling-machines : 360 
feet a week being driven in rock-salt that was harder than coal. 
He wished that such a speed could be secured in coal-mines: 
they could not touch 360 feet a week at the mines that he had to 
do with. He could scarcely believe that rock-salt was harder 
than coal. 

Mr. Thompson stated that the tunnelling-machine was worked 
continuously by three shifts of men, eight hours each. Brine 
and rock-salt were both worked, because both were required by 
the United Alkali Company, Limited. Two processes were 
worked, in one of which salt was required in the shape of brine. 
The rock-salt was mined mainly to supply tho salt required at 
the works at Widnes and St. Helens, and a considerable quantity 
was required for export, because rock-salt was admitted at a lower 
rate of duty than manufactured white salt. Brine was raised 
from about ten bore-holes, each one being independent of the 
other, all in the neighbourhood of the Freesall mine. In his 
experience, a bore-hole became useless, after a certain quantity 
of salt had been extracted from it. The original level of the sea 
was not maintained because the land did not retain its level; 
and there must have been tremendous upheavals at times. 
Cutting was carried on incessantly, and the cut was made across 
the face. 

Prof. W. Boyd Dawkins said that salt was merely the result 
of the evaporation of sea-water. He would expect to find a 
variation in a thick bed of rock-salt like that at Fleetwood, for 
the very simple reason that, in various stages of the evaporation 
of sea-water, different minerals were deposited. It was very 
largely, therefore, a question of the degree of concentration of 
the water from which that salt had come. With regard to the 
present level of the sea, it was quite an accident that rock-salt 
should be in this relation to it in this place, but in the British 
Isles nearly all rock-salt was below sea-level. In the vicissi- 
tudes of time, after the Triassic rocks had been formed in the sea, 
they were thrown into a series of folds, and parts of these folds 
were worn away by denudation ; and the salt had been washed 
out of most of them down to sea-level. Consequently, there was 
very little rock-salt in Britain above sea-level. 



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802 DISCUSSION — aOCK-SALT DEPOSITS AT PEEESALL. 

Mr. John Kigby (Winsford) said that rock-salt was found in 
Cheshire above sea-level. 

Prof. Boyd Dawkins asked whether it was known that rock- 
salt occurred above sea-level in any other part of Britain, and 
remarked that this was an exception to the general rule. There 
was a large district near Burton, whence the salt had been dis- 
solved out, leaving the broken and disjointed red marls, and in 
some cases the casts of salt-cry&tals in the rock, as evidence that 
it was formerly present. 

Mr. Dickinson said that Mr. Thompson gave the geological 
view of rock-salt formation, and refrained from expressing hia 
own opinion. Was it not quite possible that the sea obtained 
its salt from the rock-salt, rather than by the reverse process, 
namely, that the salt was the result of the evaporation of sea- 
water ? 

Mr. Thompson thought that it was the accepted theory that 
the earth was gradually cooling down. If they reversed the 
process and assumed that the earth was gradually becoming 
hotter, the water would become steam, and salt would be left. 
The same rule would apply when the earth was cooling down, 
and the last occurrence would be that of steam condensing into 
water. 

Prof. Boyd Dav^tkins said that the earth was originally in a 
heated condition, like the sun. As it gradually cooled down, it 
would arrive at such a stage that chlorine and sodium would 
combine together in the atmosphere, and a deposit of salt would 
be formed over the surface ; and hydrogen and oxygen combining 
together, would form water. Thus the sea was salt from the very 
beginning. The salt-fields of Britain were all derived directly 
from the evaporation of sea-water. 



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DISCUSSION — THE COURRIERES EXPLOSION. 808 



THE NORTH STAFFORDSHIRE INSTITUTE OF MINING 
AND MECHANICAL ENGINEERS. 



GENERAL MEETING, 

Hkld at the North Stafford Hotrl, Stoke.ttpon-Trent, 

April 8th, 1907. 



Mr. JOHN NEWTON, President, in the Chair. 



The minutes of the last General Meeting were read, confirmed 
and signed. 



The following gentleman, having been previously nominated, 
was elected: — 

Associate— 
Mr. Albert Marshall, Florence Colliery, Longton. 



DISCUSSION OF MESSRS. W. N. ATKINSON AND A. M. 
HENSHAW'S PAPER ON "THE COURRlilRES 
EXPLOSION."* 

Mr. W. G, Peasegood asked what was the cause of the second 
Josephine fire, discovered on June 2Gth, 1906, three months after 
the explosion. 

Mr. A. M. Hexshaw replied that it was believed to have 
been caused by the explosion, which had been smouldering the 
whole time, not having been discovered until three months after- 
wards. The two Josephine fires were attributed to the flame of 
the explosion. 

Mr. E. B. Wain asked what were the conditions as to the 
storage and use of explosives. Were large or only limited 
quantities taken into the mine.^ 

* Trans. Inst. M. E., 1906, vol. xxxii., pages 439, 340 and 507 ; and vol. 
xxxiii., page 124. 



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804 DISCUSSION — ^THE CXJFRElilRES EXPLOSION. 

Mr. A. M. Henshaw replied that only limited quantities 
were taken, as they (in England) took them. Explosives were 
not stored in the mine. 

Mr. E. 0. SiMCOCK asked what was the amount of explosives 
in the Lecoeuvre heading at the time of the explosion. 

Mr. A. M. Henshaw replied that seven cartridges were found 
intact in the box after the explosion, and he believed that such 
was the amount given out to the men that morning. 

Mr. E. B. Wain asked whether the explosion was suflSciently 
violent to explode the explosives. 

Mr. A. M. Henshaw said that he could not answer the ques- 
tion, but, in many cases, explosives were found intact in different 
parts of the workings. 

Mr. E. B. Wain asked whether average dusty main roads 
as found in average English collieries were comparable to these 
roads at the Courri^res pits. 

Mr. A. M. Henshaw replied that the condition of the main 
roads of the Courrieres pits was very similar to the average main 
roads of the average English colliery — ^not more dusty and not 
less. Of course, the roads were more dusty in some places and 
less in others, but, generally speaking, they were about on a 
par with those of an ordinary dry English colliery. 

Mr. E. B. Wain asked whether the main roads were packed 
roads or driven narrow headings. 

Mr. A. M. Henshaw replied that the roads were of both 
classes, but mainly headings. Straight work and longwall was 
worked; many of the roads were packed roads ; but the majority, 
he supposed, were straight roads driven in the coal. 

Mr. Hugh Johnstone (H.M. Inspector of Mines) said that 
Mr. Henshaw might have been justified inanswering Mr. Wain's 
question, Scotch fashion, by asking another, namely, what did 
he mean by an average dusty road in an English colliery ? He 
thought that it was practically impossible to fix any standard by 
which to decide definitely whether a road was dusty or not. 
The Wingate Grange explosion took place on a main intake road. 



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DISCUSSION — ^THE COUEElilBES EXPLOSION. 80& 

with which he was well acquainted, and he had travelled scores 
of roads in North and South Staffordshire collieries much more 
dusty than that road in Wingate Grange colliery. It was a road 
which probably no one present would have considered a dusty 
one, if they had travelled along it ; and yet an explosion origin- 
ated on it and wa« propagated along it. With reference to the 
initiation of an explosion in a mine, where the roads were dusty, 
and presumably free from fire-damp, he would like to know 
whether the writers of the paper considered it to be essential that 
there should be a detonation, as in the Lecoeuvre heading; or 
whether a flame sufficiently large and of sufficiently high tempera- 
ture would suffice. He thought that it was practically admitted 
that the imperfect detonation of high explosives in confined places 
might initiate an explosion in a dry and dusty road. Several cases 
seemed to establish that clearly ; but he was not sure that there 
were sufficient data available to enable them to determine what 
size or temperature of flame was necessary to ignite coal-dust with- 
out detonation. There was evidence that a sufficiently large flame 
would ignite coal-dust, but there was almost always a difficulty in 
proving the entire absence of fire-damp. It was known that a per- 
centage of fire-damp, not sufficient to be capable of detection by 
ordinary means, could be exploded in a dusty atmosphere; but 
there wa« frequently a difficulty in determining after an explosion 
whether any, or how much, fire-damp might have been present^ 
when the explosion was initiated. To illustrate the facility with 
which coal-dust might be ignited by a sufficiently large flame, he 
might refer to an incident which had occurred at a Scotch mine : a 
tub of dust, filled on one of the main haulage-roads — ^not on 
account of suspected danger, but because it was found to be an 
inconvenience — ^was sent to bank, and the contents were shot into 
the fire-hole, to be mixed with the slack for the boiler-fires. The 
fireman had just cleaned out the fires and the hot clinker lay in 
front of them. As the dust was shot over, the lighter particles rose 
in a dense black cloud, and, on their coming into contact with the 
burning clinker, it was at once ignited, the flame rising 30 feet 
into the air. There could have been no fire-damp there, and it 
showed that the dust could be ignited by a sufficiently hot flame. 
If this was established, it pointed to a serious danger in all dusty 
mines ; because there were several means by which a large flame 
might be produced. He referred more particularly to the dangers 



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S06 DISCUSSION — THE COURRIERES EXPLOSION. 

arising from the use of electricity as a motive power : the cables 
were usually laid along the intake roads, and no means had been 
devised of eliminating the danger of a flare-up through a fall of 
Toof rupturing or damaging a cable. He did not know that this 
had actually occurred, but it was more than possible ; and this 
or any breakdown of the insulation might ignite blowers or local 
pockets of gas and initiate an explosion. It appeared to him to 
be worthy of the consideration of mining engineers, because one 
could easily understand that an explosion of that sort initiated in 
a dry and dusty main road might sweep the whole pit. The 
risks were so great that any trouble incurred in eliminating them 
was repaid. He knew that there were inconveniences from the 
application of water, but he had an impression that in many cases 
the difficulties were greatly exaggerated. Of course, a road 
with a fire-clay floor and deluged with water wa.s liable to heave ; 
but it was not necessary to have a large excess of water perco- 
lating through the floor. If water were applied only in sufficient 
quantity to damp the dust, he questioned whether it would have 
the effect of making the bad floor that had usually been experi- 
enced, simply because an excess of water had been used. That was 
largely the cause of the heaving of the floor. The authors referred 
in several places to dust-free spaces ; and, accepting the accuracy 
of their conclusion that these dust-free spaces were a barrier to 
an explosion, he should like to know whether the authors had 
formed any opinion as to the length of dust-free space necessai-y 
to break or interrupt an explosion. It was mentioned that a 
distance of 230 feet (70 metres) had been sufficient to stop the 
^explosion, and he should like to know whether there were any other 
cases showing what length of dust-free space was necessary to pre- 
vent the flame from travelling. The authors had also stated that 
in some of the roads the dust had been shown by analysis not to 
be highly inflammable. He should like to hear an expression 
of opinion from the members as to the disadvantage and the 
<langer that might arise from an admittedly non-inflammable 
dust. Travelling along turnpike roads, they knew the incon- 
venience of being enveloped in a dust-storm, which rendered 
respiration practically impossible ; but what would be the result 
of that dust-storm, in the confined space of a mine, lasting for, 
not a few seconds, but half an hour? There was a possibility 
that many of the deaths reported as due to asphyxiation had been 



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DISCUSSION — THE COUERlfeRES EXPLOSION. 807 

really due to suffocation by the action of non-inflammable dust, 
whicli had not subsided before life was extinct; and, conse- 
quently, the treatment of dusty roads should not be limited to 
those coated with inflammable dust ; but all dusty roads whatso- 
ever should be treated. The writers stated that the three fans 
were not injured by the explosion, and he should like them to say 
whether any special precautions were taken in the erection of the 
fans by placing them some distance from the pit or protecting 
them with safety valves ; or whether their immunity from injury 
was simply due to the explosion not having reached them. The 
members were under enormous obligations to Messrs. Atkinson 
and Henshaw fbr the trouble that they had taken in communicat- 
ing this careful study of the explosion and of the lessons to be 
drawn from observed facts ; and the following of their arguments 
to a logical conclusion might have the effect of minimizing the 
risk of dust-explosions in that district, and of saving many lives. 

Mr. W, G. CowLisHAW said that Mr. A. H. Stokes had enunci- 
ated another theory as to the origin of the explosion.* 

Mr. William Lockett asked whether the authors were entirely 
satisfied that fire-damp had nothing to do with the ignition of 
coal-dust. In his experience, he had known very sudden out- 
breaks of gas. In 1883, a sudden outburst of gas filled the work- 
ings for a distance of 7,200 feet : this occurred at a fault, but 
fortunately no life was lost, although there might have been, 
inasmuch as at that particular period the ordinary Davy lamp 
was in use, and not until afterwards was the Marsaut lamp intro- 
duced. In 188(5, another outburst of gas took place in a goaf and 
again filled the workings, and he wondered whether a sudden out- 
burst of gas might not have been concurrent with the firing of 
this shot. He (Mr. Lockett) suggested that fire-damp might have 
been liberated by the shot fired in the Lecoeuvre heading, or from 
the fault, crossing the heading parallel to the Lecoeuvre heading, 
or from one of the large faults that crossed the coal-field. 
It was stated that : ** neveiiheless fire-damp was not entirely un- 
known, as it is recorded that, in 1904, a miner was burnt by fire- 
damp, ignited by a naked light,"t and that the '' regulations . of 
the Pas-de-Calais mines-inspection district require safety-lamps 

* Trans, Inst. M. E., 1906, vol. xxxii., page 34L 
t lb\d,t page 454. 



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808 DISCUSSION — THE COURRIERES EXPLOSION. 

to be used in headings and stone-drifts."* It was rather strik- 
ing, taking the huge amount of old workings or goaf into con- 
sideration, that this stipulation should be in force, and that open 
lights should be allowed in other parts of the mine, practically 
in the same ventilating district. 

Tfo. 3 pit, a winding, downcast and upcast shaft, divided hy 
wooden partitions, was the ventilation centre of a large district, 
and situated at distances of 3,800 and 4,200 feet from Ifos. 2, and 
4 and 11 pits respectively. He (Mr. Lockett) asked whether this 
single pit was sufficient for the ventilation of the area of work- 
ings governed by its position. Further, the use of wooden parti- 
tions rendered this pit liable, in case of accident* to become im- 
passable; and, after the explosion, this shaft was completely 
blocked by debris at a depth of about 600 feet. 

Mr. E. B. Wain thought that North Staffordshire engineers 
were generally convinced that coal-dust per se was an explosive 
agent, and whatever might have been the primary cause of 
ignition in this particular case, whether it was a blown-out shot, 
whether (as had been suggested by Mr. A. H. Stokes) some one 
had been tampering with explosives and caused a small explosion, 
or whether (as suggested by Mr. Lockett) there had been a small 
gas explosion in the Lecoeuvre heading, there seemed little doubt 
that coal-dust propagated the explosion throughout the whole 
area. The analyses raised the question as to whether certain 
dusts were incapable of propagating flame. Many years ago> 
Sir Frederick Abelt obtained explosive results with magnesia- 
dust in a mixture of 2| per cent, of fire-damp and air, not in- 
flammable per se, and if that inert substance was capable, shale 
might also be capable of propagating an explosion. This accident 
had proved very clearly that it was not desirable to couple large 
groups of workings together in the rough-and-ready way in 
which they appeared to have been connected at the Courriferes 
collieries, so that an accident in one might affect the whole. 
Some of them had learnt that lesson already, but he thought it 
was a lesson that might still be thought over with advantage. 

* Trans, Inst, M, E., 1906, vol. xxxii., page 444. 

t Report on the Be^ndts of Experiments made icith Samples of Dust collected at 
Seaham Colliery, by Prof. F. A. Abel, 18S1 [C. -2923J, page 9 ; and Final Report 
of H.M, Commissioners appointed to inquire iiUo Accidents in Mines, 1886 [C.— 
4699], page 155. 



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DISCUSSION — ^THE COUBJtiiltES EXPLOSION. 809 

Mr. F. H. Wynne said that there was one point against the 
theory of the explosion originating at the powder-box. This box 
was found a long way from the face, a considerable distance out- 
bye from where the mutilated body of the fourth man lay ; and 
it was found practically intact, the cartridges served out in the 
morning were in it and were not exploded, so that unless there 
was a second powder-box in the heading, which seemed unlikely, 
there was not much possibility of the coal-dust having been 
ignited by that means. This explosion taught the necessity of 
isolating one district or seam from "another by the requisite 
length either of thoroughly watered roadway or of bricked arch, 
which, whether white-washed or not, could be kept clean and 
free from dust with very little difficulty. At Wingate Grange, 
a workmaai, firing an explosive, through ignorance apparently, 
caused a disaster which cost twenty-four lives ; and a somewhat 
similar case occurred recently in North Staffordshire. He 
thought that it was the duty of every manager to drill into the 
minds of firemen and shot-firers the dangers of the explosives 
which they were using, and the necessity of complying absolutely 
with the conditions laid down in the Home Office Order for the 
use of explosives in dusty or in any other mines. 

Mr. J. Gregoey asked whether the special method of timber- 
ing adopted at the Courrieres collieries* had prevented or mini- 
mized the heavy falls, which as a rule obstructed the work of 
rescue following upon an explosion. Another question arising 
out of the discussion was the indefinite information regarding 
the conditions under which coal-dust was liable to initiate or 
propagate an explosion. He believed that, even at the present 
day, there were mining engineers who would not admit the danger 
of coal-dust in an atmosphere free from gas. They were in a 
minority ; but even amongst those who had accepted the fact and 
had studied the question there was no certainty as to the relative 
immunity of coal-dust mixed with metal-dust, as compared with 
pure coal-dust. It was generally agreed that a length of wet road- 

* " Methods of Preventing Falls of Roof adopted at the Courrl^s Collieries," 
by Dr. C. Le Neve Foster, Mines and Quarries : General Report and Statistics for 
1899, pa^e 74, and Trans, Inst, M. E,y 1900, voL xx., page 164; and HepoH to 
His Majesty's Secretary of State for the Home Department on the Methods of 
Preventing Falls qf Roof adopted at the Courrieres Collieries, by Messrs. W. N. 
Atkinson, C. Le Neve Foster, John €rerrard and Henry Hall, H.M. Inspectors of 
Mines, 1901. 



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810 DISCUSSION — THE COURRIERES EXPLOSION. 

way, or a length from which the dust had been removed, would 
isolate an explosion ; but, so far as he was aware, there were no 
data which would enable one to determine with certainty what 
minimum length would prove effectual. He suggested that 
experiments ought to be made on a large scale in an experimental 
gallery. The Government had provided a gallery for the testing 
of explosives; and, failing any action by the Government on 
this important question, this work might be undertaken by The 
Institution of Mining Engineers in order to decide the relative 
susceptibility of the various classes of dust and the efficiency of 
the several suggestions for isolation. 

Mr. M. Walton Brown wrote that Messrs. H. Le Chatelier, 
chief inspector of mines; de Morgues, mining engineer at the 
Blanzy collieries; and Cordier, delegate-miner, appointed to 
report in the judicial enquiry, had suggested five causes of the 
explosion: — (1) The fire in the Cecile seam; (2) a shot in the 
LecoBUvre heading might have ignited a small volume of fire-damp, 
initiating a general dust-explosion ; (3) an ignition of dust : the 
suggestion of a general explosion of dust, ignited by a shot, made 
by Messrs. H. Cunynghame and W. N. Atkinson,* had not been 
accepted ; (4) the explosion of a small volume of fire-damp at or 
near the face, ignited by the flame of an open lamp ; and (5) the 
clandestine and unlawful storage of explosives in an air-pipe in 
the Lecoeuvre heading. The force of the explosion in that heading 
was most formidable and inexplicable, because the minimum 
force was most generally found at the seat of an explosion. 

The experiments of the committee of The Xorth of England 
Institute of Mining and Mechanical Engineers had shown con- 
clusively that: — *' (1) The high explosives . . . are less liable 
than blasting-powder to ignite mixtures of air and coal-dust, with 
or without the presence of fire-damp. These explosives cannot be 
relied upon as ensiiring absolute safety. (2) The experimciuts have 
shown that ignitions of mixtures of air and coal-dust, with or 
without the presence of fire-damp, can be obtained when there 
is present a much smaller quantity of coal-dust than has been 
previously supposed to be neces8ary."t Five ignitions of coal- 

• Report to H,M, Secretary qfStcUe/or the Home Department on the Disaster 
which occurred at Courriires Mine, Poa de Calais, France, on March 10th, 1906, 
by Messrs. H. Can>^ghame and W. N. Atkinson, 1906 [Cd..3171]. 

+ Report of the Proceedings of the Flameless Explosives Committee of the North 
of England Institute of Mining and Mechanical Engineers, 1896, page 103. 



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DISCUSSION — THE COUEKIEEES EXPLOSION. 811 

dust in suspension were recorded in their experiments with un- 
stemmed safety explosives (Table I.) J* ^^^ blasting-powder 
ignited coal-dust, in suspension' and in situ, in 28 out of 32 ex- 
periments (Tables I, K, L and M).t It was possible, therefore, that 
an ignition of coal-dust, in the entire absence of fire-damp, 
resulted from the improper firing of an explosive. 

Mr. H. Johnstone said that some years ago the idea was put 
forth that coal-dust might be removed by a system of aspiration 
— the vacuum-process of to-day ; and when that idea was mooted 
it was laughed at as impracticable. Anyone conversant with 
mining knew that the removal of the dust throughout the whole 
of a mine by such means would be impracticable; but the 
system might be applied to the removal of dust from short spaces, 
especially if these spaces were bricked and arched as Mr. 
Wynne had suggested. Vacuum-cleaners could be introduced 
at small cost, and power could be easily applied to work them. 

Mr. A. M. Henshaw, in reserving his reply to the discussion, 
said that he must acknowledge his indebtedness to his assistant^ 
Mr. McGowan, for the admirable plans attached to the paper. 



• Report qf the Proceedings of the Flameless Explosives Committee of the North 
of Sngland Institute of Mining and Mechanical Engineers, 1896, pages 96, 118. 
and 121. 

t Ihid,, pagea 122, 127, 129 and 133. 



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312 TRANSACTIONS. 



THE NORTH STAFFORDSHIRE INSTITUTE OF MINING 
AND MECHANICAL ENGINEERS. 



GENERAL MEETING, 

Held at the Nobth Stafvobd Hotel, STOKE-upoy-TREKT, 

June 3rd, 1907. 



Mr. J. G. GADMAN, Past.Prbsident, in the Ghair. 



The minutes of the last General Meeting were read, confirmed 
and signed. 



The following gentleman, having been previously nominated, 
was elected : — 

Member— 
Mr. H. T. Pebworth, Asylum Villas, Gheddleton, Leek. 



Mr. F. E. Buckley's paper on " Outbursts of Coal and Gas 
in the Cockshead Seam, Shelton Colliery," was read as follows : — 



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OTTTBURSTS OF COAL AND GAS. 818 



OUTBURSTS OF COAL AND GAS IN THE COCKSHEAD 
SEAM, SHELTON COLLIERY. 



By F. E. BUCKLEY. 



Introduction, — Outbursts of coal and gas had been unheard of 
in North Staffordshire until the past few years, and it is thought 
that on account of those which have occurred in the Cockshead 
seam, worked at the Deep pit at Hanley, might be of interest to 
the members. 

The Cockshead coal-seam lies at a depth of 2,550 feet from 
the surface, and has an average thickness varying from 7 feet to 
7 feet 6 inches. The upper portion, about 3 feet 6 inches thick, 
is usually of a softer nature than the lower portion. The roof 
is strong grey metal, with bands of rock, and the floor is a strong 
dark stone. The general inclination of the seam varies from 
14 to 17 degrees, from east to west. There are, in an area within 
1,500 feet of the shafts, numerous small faults usually running 
north-west and south-east, and north-east and south-west. 

Each outburst, described in this paper, occurred at a point 
where a fault intersected the seam; and, in each case, where 
the coal, at the point of contact with the fault, became light, 
porous, friable, and dull in appearance, for a width varying 
from 18 inches to 3 feet. 

With the exception of the last occurrence, there had been no 
indications whatever that an extraordinary quantity of fire-damp 
was present; but, prior to each outburst, one or two unusually 
heavy " goths '' or " bumps," sometimes accompanied by a 
peculiar grinding or rending noise, had taken place. Heavy 
goths were, however, of frequent occurrence in this seam when 
heading out, and no special importance was attached to the 
goths preceding these outbursts; especially, as in many cases, 
it had been thought that the goths did not arise from any 
severance or movement of the coal, but from the roof. 

First OiUbvrst. — The first outburst occurred in a rise heading, 
A (fig. 1, plate xi.), where a roll had been met with, and the 

VOL. XXXIII.~1M6.1907. 24 



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814 OUTBURSTS OF COAL AND GAS. 

coal was of the hard, dull character frequently seen in the 
vicinity of faults. This heading was 12 feet in advance of the 
line of the top level, which was then within 8 feet of inter- 
secting it. 

At 3 p.m., on September 24th, 1903, a collier was eng^aged 
in cutting coal on the north side of the heading on the roll, 
when a terrific goth took place, dislodging a large quantity 
of coal and releasing a huge volume of gas (figs. 2 and 3, plate 
xi.). The loader, whose light was extinguished, 15 or 20 
feet from the face, saw or felt the rush of coal ; he shouted to 
the collier, and receiving no reply, he fortunately rushed out 
for assistance. Otherwise, he would undoubtedly have been 
overcome by the large quantity of fire-damp, which immediately 
filled the heading. A, and the main level to B (fig. 1, plate xi.). 

Officials, on the scene within 5 minutes of the occurrence^ 
could not proceed beyond B, owing to fire-damp being present in 
great quantity, and steps were taken at once to remove it. 
Eventually it was cleared to the bottom, C, of the rise heading 
(fig. 1, plate ^i.). Another heavy goth then occurred, and 
the level was again filled with fire-damp to the point B. The 
operations were recommenced, and progress was made until the 
jig-post, d, could be seen (figs. 2 and 3, plate xi.). A third 
heavy goth, discharging more fire-damp, drove the workers back 
again to the bottom, C, of the heading; but, the goths having 
ceased, the fire-damp was removed sufficiently, and the body of 
the collier, g, was recovered 4 hours after the outburst. On 
examination, he was found to have received severe injuries to 
the face sufficient in themselves to cause death, indicating that 
he had received the force of the outburst of material immediately 
in front of him, or that he had been blown either against the roof 
or the timber. The body was found upon the blown-out material, 
and there was practically no material lying on the man.. The 
section (fig. 3, plate xi.) shows ihe position assumed by the 
blown-out material, hi^ and the amount of coal, ef, thus displaced 
was approximately 10 tons. This heading was continued about 40 
feet in order to prove the fault, but was carried no further 
(fig. 4, plate xi.). 

The detailed plan and sections of the rise heading (figs. 4,. 
5 and 6, plate xi.), show that the roll was very irregular in 
its contour, and that there was a considerable difference on the 



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OtTTBUBSTS OF COAL AXD GAS. 815 

two sides of tlie heading. The theory advanced at the time was 
that a large quantity of fire-damp was contained in a small area 
or i)Ocket of the dull friable coal, under very great pressure ; and 
that the collier, cutting near one of the ridges of the roll, had 
BO weakened the harder crust surrounding this area that ulti- 
mately the pressure overcame the resistance and the occluded gas 
suddenly burst out. 

Second Outburst. — The second outburst occurred in a rise 
thirling, which was being driven between two levels running to 
the north. Two men were engaged there, and both of them were 
killed. 

For a distance of 450 feet, the top level had been driven along- 
side a downthrow fault, which ran irregularly on the rise side 
of it. This fault caused no trouble, except in the timbering; 
but, owing to its irregular course, it was touched frequjently, 
without, however, revealing any undue pressure, and at various 
points it made a quantity of water, which soon dried up. 

On one occasion along this length, a collier was cutting the 
top coal in a kneeling position, when some heavy goths occurred, 
which he stated " lifted him up off his knees." No special 
importance was, however, attached to this occurrence, for, as 
above stated, the seam is subject to goths, which at times are very 
severe, and frequently release much fire-damp. The coal was 
very strong, and it was noticeable that the goths did not set free 
any considerable quantity of fire-damp. 

In due course, the rise thirling was commenced ; and, as the 
fault had crossed the top level, it was expected that it would be 
found in this thirling. On February 12th, 1904, the thirling 
was driven upward, a distance of 50 feet to D (fig. 1, plate xi.), 
in hard coal; and was rapidly approaching the fault, when at 
7*20 p.m., a tremendous goth took place. In the words of the 
colliers who were working in the top level, " it sounded as if the 
whole earth was tearing up." This so alarmed them that they 
hurried down to the main level ; and, hearing nothing from the 
rise thirling, they managed to reach the bottom of it by crawling 
below the fire-damp, which, however, increased so rapidly as to 
cause them to withdraw. 

Efforts were at once made to reach the rise thirling, but the 
fire-damp was present in such great quantity, that it took 2 



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316 OUTBURSTS OF COAL AND GAS. 

Lours to reach the body of the collier, o, who was found lyings 
on his face 26 feet up the thirling (figs. 7 and 8, plate xi.). 
Artificial respiration was unsuccessful; and, his mouth being 
full of coal-dust, the medical opinion was that he had been 
asphyxiated, no other injuries being found. 

The body of the loader, n, was reached 4 hours after the 
outburst, his legs having been pinned under some timber and 
roof, which had fallen or been displaced at the time of the out- 
burst. Although he had received severe injuries, yet medical 
examination showed that the immediate cause of death was 
asphyxiation. After clearing the thirling of fire-damp and 
debris, it was found that coal had been blown out from the point 
of contact of the seam with the abovementioned downthrow 
fault. The force of the outburst had blown out six bars, broken 
the jig-post, m (a larch-post, 10 inches in diameter), and caused 
a heavy fall of roof. 

There was every indication that the collier had been cutting 
the coal, thus weakening the crust of good coal, gh, against the 
fault (which had a thickness of 3 feet of this dull sooty coal, ti, 
lying against it). He had then gone from the face, probably to 
put a sharp blade on his pick, leaving the loader at the face, 
when suddenly the outburst took place, and he was overcome by 
shock and fire-damp before he could get away. 

This outburst was so severe, that it affected the level and 
roads in the vicinity. The roof in the adjacent roads became 
broken, and a large proportion of the bars in the main level, 
then 150 feet in advance of the rise thirling, were broken at the 
moment of the outburst, and the pillar of coal between the two 
levels was shaken. The force of the outburst was extremely 
heavy, evidently relieving a considerable area of an abnormal 
pressure. It was afterwards noted that the coal was even 
stronger to cut than previously, and that it made practically no 
gas for some time afterwards. The lower level was subsequently 
carried through the same fault, but no indication of gas or 
abnormal pressure was noticed there. 

In consequence of the disastrous effects of these two outbursts, 
and in consequence also of the difficulty of foreseeing them or 
of preventing their recurrence, it was decided that the only 
practicable precautionary method was to adopt a system of ad- 



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OUTBUaSTS OF COAL AND GAS. 817 

vance bore-holes in all level and rise headings. This was hardly 
expected to prevent such outbursts, but it was hoped that pos- 
sibly some indications would be given of the near proximity of 
£tny enormous pressure, such as had already been encountered. 
Bore-holes, 2^ inches in diameter, were at once put in as far as 
possible with a Bumside long-hole boring-machine ; the heading 
was then cut to within 9 feet of the extremity of the bore-hole ; 
and then another hole was bored. In the case of approaching 
the supposed position of a known fault, or of frequent goths 
taking place, one and even two flank bore-holes were also bored 
to test the pressure ; and, in a few instances, considerable quan- 
tities of gas, as well as water were tapped and relieved. In no 
case was there any sudden appearance of gas under pressure in 
the bore-holes ; and it is, therefore, by no means certain that any 
bore-hole has encountered an area of pressure similar to those 
which produced the fatal accidents just described. Some of the 
holes were frequently filled with crushed coal as soon as they 
had been bored; but, beyond this, nothing extraordinary has 
occurred, although these bore-holes have been continuously 
maintained in narrow headings. 

Third Outburst, — The third outburst occurred at a depth of 
about 2,800 feet, where two levels were being driven 90 feet 
apart. It was noted that the coal at the face of the top level 
was all " on the work " ; and that, in place of an occasional goth, 
there occurred a series of goths, follqwing each other at short 
intervals. The collier was kneeling on the bench of bottom 
coal cutting the top coal, when a goth much heavier than the 
rest knocked out a bar; and, immediately afterwards, the full 
face of top coal, 10 feet wide by 3 feet 6 inches in height, sud- 
denly burst outwards at E (fig. 1, plate xi.), and partly buried 
the collier. The estimated quantity of coal thus displaced was 
2 tons ; and, at the same time, the heading was filled with fire- 
damp for a distance of 10 to 15 feet back from the face, although 
ventilating pipes, 18 inches in diameter, were fixed to within 
2 feet of the face. 

On removing this debris, it was found that an upthrow fault 
of about 18 inches, running north-west and south-east had been 
bared, and that 18 inches of the dull sooty coal had lain against 
it. The goths had ceased, and the coal on the upper side of the 
fault was of its usual appearance. 



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818 OUTBUESTS OF COAL AND GAS. 

The bearing of this fault was taken, its position in the main 
level and in the next rise thirling* estimated, and this informa- 
tion given to the officials. The colliers were specially warned of 
its position; and ordered, should anything unusual occur, to 
withdraw at once, and fetch out the top-level men as soon as 
possible, as the air-current would pass on to them from the 
main level. 

The rise thirling was commenced in due course, and an extra 
flank bore-hole was put in to meet the fault. This hole gave ofE 
water only; but the centre bore-hole was giving off water and 
sufficient gas to fire in a safety-lamp at the outer end of the hole. 
The fireman, on examining this thirling at 7 a.m. on January 
24th, 1907, heard peculiar gurgling noises at the face; but this 
gave rise to no apprehension, as it was considered that it was 
caused by the water at the extremity of the bore-hole. 

At 12'30 p.m. on the same day, he again examined the thirl- 
ing ; the face was then working considerably, the gurgling noise 
was continuing, and frequent goths were taking place. Within 
half an hour, a very heavy goth occurred, causing the men to 
withdraw from the face ; and this was followed in a few minutes 
by the face of coal, F (fig. 1, plate xi.), suddenly bursting 
away, followed by some roof, adjoining the slip of the fault, 
which liberated a quantity of water and fire-damp, the latter 
filling the thirling for the whole of its length of 54 feet down 
to the landing-plates on the level. 

The water washed the displaced coal (54 cubic feet) and dirt 
(162 cubic feet) ; and distributed it on the floor of the thirling, 
and to a depth of 6 inches on the landing-plates at the bottom. 

The top-level colliers were fetched out at once, no one being 
injured and no lights extinguished. In this case also, the goths 
discontinued immediately after the outburst. The fault was 
again proved at Q- (fig. 1, plate xi.) in the main level; but, 
although centre and flank bore-holes were put in, no extra pres- 
sure was encountered, the outburst in the thirling having 
evidently relieved it over this area. 

Conclusions. — From the foregoing descriptions, it will be 
seen that prior to each of these outbursts an unusual number of 
goths occurred ; and, although the seam is subject to goths 
in its normal condition, the writer is of opinion that such areas 



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OUTBUESTS OF COAL AND GAS. 819 

of great pressure, can, to a limited extent, be located by care- 
fully noting these goths, and serious accidents can be avoided by 
the use of advance bore-holes and by the withdrawal of men 
until the disturbances should subside. In the last outburst, 
there can be little doubt that a fatality would have occurred, 
unless the bore-holes had been maintained and the experience 
gained from previous occurrences acted upon. 

It is difficult to suggest any reason for the occurrence of these 
patches or pockets of coal containing fire-damp under such great 
pressure in the particular locality with which this paper deals. 
The Cockshead seam has been worked for many years to the 
south-east and to the north-east, but at shallower depths. At 
the time of the occurrence of these outbursts, this seam of coal 
was being opened out at practically the same depth at the 
adjoining colliery on the north; but, so far as the writer is 
aware, no similar occurrence had ever been met with either in 
this or any other seam at neighbouring collieries. It therefore 
appears that the depth has no bearing upon the occurrences above 
recorded. 

What seems to have some greater bearing upon the ques- 
tion is the fact that the large downthrow north-and-south 
fault of 300 feet, known as the Far Green fault, splits up 
into two faults as it passes southwards on the west of the Deep 
pit. One of these faults, with a downthrow of about 66 feet, 
maintains the general direction of the main fault; and the 
other, a downthrow fault of 150 feet, takes a south-easterly 
direction. The area of strata, contained within the curve 
formed by the severance of the larger fault from the main fault, 
is broken up by numerous small dislocations ; and it is at these 
dislocations that the outbursts have occurred. These disloca- 
tions are more numerous in the Cockshead seam than in any of 
the upper seams, and the Cockshead seam is much less disturbed 
in the north, where the Far Green fault makes one direct step of 
300 feet. It may, therefore, be suggested that in the process of 
faulting, the seam had been subjected to abnormal pressure, and 
thereby isolated patches of disintegrated coal had been formed, 
such as have produced these outbursts. 

An analysis of the blown-out coal throws no light upon the 
subject, as it is practically the same as that of the normal seam. 

A considerable extent of longwall-face has been opened out to 



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820 DISCUSSION — OUTBURSTS OF COAL AND GAS. 

the north of the site of these occurrences, and there have been 
no indications of fire-damp under great pressure in this face. 
It is only fair to say, however, that the face is comparatively 
free from faults ; but, when the longwall method of opening out 
this seam was decided upon, it was hoped that the larger area 
of coal exposed at the face would ensure that any accumulation 
of excessive pressure would relieve itself over a wider area than 
could be the case when it was approached only by a narrow 
heading. 



The Chairman (Mr. J. C. Cadman) said that Mr. Buckley had 
given the members an historic record of some of those occurrences 
which now more frequently happened in deep mining, and the in- 
formation would be valuable to those engaged in that class of 
work in this or in any other district. This new feature of danger 
would have to be carefully met, as pointed out in Mr. Buckley's 
paper. 

Mr. W. X. Atkinson (H.M. Inspector of Mines) wrote that he 
had investigated the accidents caused by the outbursts of 1903 
and 1904 ; * and it seemed probable that a fatal accident was 
averted by the precautions taken in the case of the fourth out- 
burst. It appeared difficult to understand the relationship be- 
tween the goths and the outbursts. Were the goths caused by 
pockets of disintegrated coal saturated with gas at high pressure ? 
Or were the goths only the means of breaking down the strong 
coal surrounding such pockets, so as to liberate the disintegrated 
coal and gas ? Although bore-holes were not a certain means of 
indicating where outbursts would take place, nor of relieving 
the pressure so as to prevent them, they were advisable where 
it wa,s thought that outbursts might occur; and the greater the 
diameter of the holes, the more useful they were likely to be. 
Alertness to observe and to be warned by indications similar to 
those noticed in connection with previous outbursts was of the 
greatest importance. 

Mr. J. T. Stobbs said that Mr. Buckley had brought before 

the members a large number of facts, which, together with the 

• Rep(yrt8 of H.M, Inspector of Mines/or the Staf&rd District for the TearlBOS, 
by Mr. W. N. Atkinson, 1904, page 24 ; and Reports of H,M. Inspector of Mints 
for the Stafford District for the Year 1904, by Mr. W. N. Atkinson, 1905 [Cd. 
2506— VIII.], page 21. 



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Fig. 4.— Plan of Heading, AC, Fiq. 1. 

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mU\\<\ ':F i^ U Xi I: 



OF Thirunq,D, Fig. 1 




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DISCXTSSION" — OUTBUESTS OF COAL AND GAS. 821 

samples of coal from the various outbursts, were of special 
interest; but those from the second and third outbursts wer^ 
very striking samples. He had not had an opportunity of seeing 
this outburst-coal previously, but he noticed that the pieces were 
all very finely coated on a few of the sides with chocolate-brown 
coal-dust, that was to say, coal-dust of the very finest powder. 
As they looked at coal, it was ordinarily black ; but, the finer 
it was ground, the browner it appeared, and this coating of the 
finest brown powder suggested that there had been considerable 
grinding action preceding the actual outburst of the coal. He 
thought that the outbursts were not due to gas-pressure, because 
the bore-holes that had been put in would tap the gas, if it existed 
under such very great pressure, and would prevent the outburst. 
The intimate connection between the outbursts and the faulted 
areas, and especially the rolls in the floor, seemed to point to 
regional disturbances that might have occurred some time pre- 
viously — it might be years and years before — or might have been 
induced by the actual workings approaching that area. What 
was the nature of the floor of the heading, in which the outburst 
of September, 1903, occurred ? Was it broken up or was it in its 
normal stratified state ? Any puckering would indicate that the 
influence of the fault had extended into the strata. The fact 
that " the pillar of coal between the two levels was shaken "* 
pointed to regional disturbances of the measures. The members 
wanted more facts, placed side by side with one another, so that 
they could form a working hypothesis of the cause of these singu- 
lar occurrences ; and when they had obtained a scientific explana- 
tion of the facts, steps might be taken to guard against the risk 
and danger attending these outbursts. 

Mr. William Lockett said that he had been working the 
Cockshead seam at an adjoining colliery by the pillar-and-stall 
and a semi-longwall system for a number of years ; and, although 
coal-outbursts were new to him, outbursts of gas were not. In 
February, 1883, on approaching a large fault, there was a 
tremendous outburst of gas, filling the whole of the workings, 
which extended roughly about 7,000 feet; and, fortunately for 
themselves and everyone concerned, no further disaster arose. 
This outburst occurred in the Cockshead seam, at a depth of 

• Trans. Inst, M. E,, 1907, vol. xxxiiL, page 316. 



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3S2 DISCUSSION — 0UTBXJEST8 OF COAL AND GAS. 

about 800 feet. Another outburst took place in the roof of the 
Cockshead seam, at a depth of about 900 feet. In this case, the 
gas was accompanied by a considerable amount of water, which 
continued to run long after the gas had spent itself. Whilst 
examining the place, he observed a man, carrying a Davy safety- 
lamp, running towards him and passing through the explosive 
mixture; and his feelings on that occasion would be better 
understood than described. The Marsaut lamp was then intro- 
duced, and minimized the danger that existed when Davy safety- 
lamps were used in the Cockshead seam. He thought that Mr. 
Buckley had introduced a very wise precaution in approaching 
these dangerous areas by means of bore-holes. 

Mr. A. M. HfexsHAW said that the members could not ignore 
the facts that had been put before them by Mr. Buckley with 
regard to the occurrence of these outbursts : (1) At a great depth ; 
<2) where the seam was faulted; (3) accompanied by outbursts 
of gas ; and (4) where soft, locally called " mushy," coal, was 
found in the neighbourhood of a fault. It seemed to him that 
all these conditions had impo^ant bearings on the occurrence 
of these outbursts, and he disagreed with Mr. Buckley that the 
depth of the workings should not be taken into consideration, 
and with Mr. Stobbs that gas-pressure had nothing to do with 
these outbursts. He had tried to picture in his mind the con- 
dition of things, and what brought them abouit; he understood 
that the great fault divided into two, and that it was in the fork 
of these smaller faults that the outbursts had taken place; and 
it seemed to him likely that the long-imprisoned gas, under great 
pressure, was chiefly responsible. It was on record that bore- 
holes had been put into seams, properly stopped, and gauges had 
recorded a pressure of 461 pounds to the square inch.* The 
conditions here gave them considerable pressure and the gas, 
under pressure, was locked up in a small pocket of friable coal, 
which had been disintegrated by fault-action and was not cohe- 
sive ; and, if a pocket of coal, containing gas at a high pressure, 
was approached by a heading or a bore-hole which perforated 
the jacket of that pocket, then it did not seem to him surprising 
that these outbursts should occur. The depth, the faulting, the 
soft coal, and the occurrence of gas all had considerable bearing 

* ** Experiments showing the Pressure of Gas in the Solid Coal," by Sir 
Lindsay Wood, Bart., Trans, N. E, Inst,, 1880, vol. xxx., page 204. 



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DISCUSSION — OUTBUKSTS OF COAL AND GAS. 828 

on the question, especially as they were always accompanied by 
goths, which showed that considerable subsidenoe-pxessure was 
brought to bear on a local area, and that the pressure, brought 
about by the driving of the roads, caused the roof-pressure. All 
the conditions helped to disturb the mass of soft coal contain- 
ing the gas, and to increaae the tension of the surrounding strata, 
until the moment when the jacket of the pocket was perforated. 
Then the outburst came, and the gas and the soft coal were dis- 
charged at the point of least resistance. 

Mr. William Lockett asked whether the Cockshead seam 
contained 3 or 4 inches of cannel coal, containing a larger pro- 
portion of gas than the remainder of the seam. 

Mr. A. M. Henshaw said that at a fault, and particularly ai a 
large fault, there was generally a " leader " or " clod," that was, 
a mixture of all the disintegrated material alongside and between 
the walls of the fault-faces, produced by the sliding action of the 
two sides of the fault. Where the fault crossed the coal-seam, 
the coal was similarly and often extensively disintegrated, the 
bedding had been destroyed, and the coal could be ground into 
dust, in their hands. The crushed coal would contain gas, like 
the coal-seam ; but the seam, in its natural condition, would not 
release its gas so freely as would the ma«s of soft coal contained 
in the pocket. When the crust or jacket of the pocket was per- 
forated, the soft coal was not sufficiently cohesive to retain gas, 
under pressure, and it would relieve and empty itself of the coal 
and the gas suddenly. 

Mr. E. 0. SiMCOCK asked how the safety-lamps behaved at the 
time of the outbursts and the general condition of the lamps 
when recovered. He had found pockets of gas, not pockets of 
coal, in the thick coal-seam of Upper Assam, at a depth from the 
surface of about 120 feet. There was absolutely nothing in 
them but gas at a high pressure, that was to say, they were quite 
empty, after the gas came out, except for the atmospheric air. 
Some extended for a length of 20 feet, and as much as 10 loads 
of stuff had been filled into them, after the gas had escaped. 

Mr. A. Hassam said that he was not in agreement with Mr. 
Stobbs, when he stated that the outbursts were not due to gas 
under pressure. Could Mr. Stobbs define what he implied by 



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B2i DISCUSSION — OrXBURSTS OF COAL AND GAS. 

a '* regional disturbance " ? They were very much indebted to 
Mr. Buckley for bringing this matter forward, and he had much 
pleasure in moving a vote of thanks to him for his interesting 
paper. 

Mr. F. H. Wynne said that a similar occurrence took place in 
1904, at Sneyd colliery, also in the Cockshead seam. The face 
was burst off, but there was no fault and no soft coal. It had 
been described as follows : — 

On August 23rd, at 7.30 p.m. ; barometer 29'76 inches, steady. Three fatally 
injured. This explosion occurred in the Cockshead seam, in a heading being driven 
to split a pillar of coal, preliminary to its removal. The seam lies at a depth of 
875 yards, and is 7 feet 6 inches thick, of clean coal. The pillar of coal which was 
being split was about 40 yards long by 25 yards wide, and the heading was driven 
20 yards in the direction of the length of the pillar, so that the face of the heading 
was about the centre of the pillar. The heading was about 7 feet 6 inches high by 
10 feet wide, and was ventilated by a range of 18 inches air-pipes, led from a 
brattice -sheet, the end of the pipes being within a few feet of the face of the 
heading. The place was examined by a fireman at 5.30 p.m., who found it safe 
and free from gas ; and two colliers and a loader went into work at 7 p.m. About 
half an hour afterwards, a brattice-man, who was working on the road about 100 
yards fron\ the face of the heading, heard a very lond goth or concussion of the 
strata. He went towards the place and heard shouts, and found the three men 
running out of the heading, the clothing of two of them being on fire. . . . Two 
of the safety-lamps (extinguished) were found hanging on posts near the face, and 
the third lamp was found impaled on the brake-handle of the jig-wheel, with the 
glass broken, the brake-handle having passed right through tho glass. The lamp 
was in such a position as it might be if it had been hanging on the lid over the jig 
post and had fallen therefrom. It was fitted with a hook for hanging up, and the 
lid of the jig-post would be a convenient place to hang it for lighting the loader. 
Before the explosion it had probably been hanging on the lid, and had been 
shaken off by the goth.* 

Mr. A. Hassam said that the occurrence at Sneyd colliery would 
be at the nearest point, in the adjoining colliery, to where these 
outbursts took place in the Cockshead seam, and at or about the 
same level. Similar occurrences had been described by Mr. 
Meachem,t and several interesting papers described outbursts 
of gas in South Yorkshire. 

Mr. J. T. Stobbs said that by the term " regional disturb- 
ances," he meant strata in bulk undergoing movement, espe- 
cially intense at local centres, due either to cosmic movements or 

♦ Reports qfH.Af, Inspector of Mines for the Stafford District for the Year 1904y 
by Mr. W. N. Atkinson, 1905 [Cd. 2506 -viii.], page 13. 

t "Notes on an Earth Explosion or 'Bump' at Hamstead Colliery," by 
Mr. F. G. Meaohem, Trans, Inst. M, E., 1893, vol. v., page 381. 



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DISCUSSION — OUTBXTESTS OF COAL AND GAS. 825 

to the draw of the working-faces or goaf. Cosmic movements 
of the earth's cmst gave rise to earthquakes and faults, and were 
most marked along belts of special weakness, such as fault-lines. 
There was no doubt that movements of this kind would produce 
in some places pockets of soft coal, and it was exceedingly pro- 
bable that in the deeper coal-seams there might be an intimate 
connection between these outbursts and earthshakes. 

The Chairman (Mr. J. G. Cadman) said that he remembered 
a very serious outburst of gas, which occun*ed whilst cutting 
through a downthrow fault of 300 feet to open out an area of 
coal that lay surrounded by faults. When the crut was 
approaching the coal-seam, a small fault of 30 feet was found, 
running parallel to the main fault, and about 10 to 12 feet 
distant from it. The strata, between these faults, during the 
week-end were thrust or forced out, and filled the crut for 20 
er 30 feet ; and although the inlet and outlet cruts were then about 
300 feet long, both were filled with gas on the inbye-side. At 
the expiration of eight or ten weeks, when the ga« was drained 
ofE sufficiently so as to allow the men to reach the face, it was 
found that the strata at the far end of the crut had been forced 
out from the main fault and doubled over like the leaves of a 
book. The gas was evidently under great pressure in situ, no 
pockets were perceived, and although no coal was thrown out, 
he considered that the pressure of gas could have lifted the 
strata. He had pleasure in seconding the vote of thanks. 

The vote of thanks was cordially approved. 

Mr. F. E. Buckley, in replying to the discussion, said that 
arguments could be used in favour of several theories, but at 
Shelton colliery they were of opinion that the outbursts were 
eaused by pockets of gas under pressure; and, of course, until 
something different was proved, that argument held good. The 
samples of coal differed, because the first outburst was entirely 
different from the other two, in which the burstings were from the 
side of a fault. The first samples were from the face of a heading 
and from the side of the heading, on the top of a roll, and there 
was no dislocation of the roof (fig. 3, plate xi.). If this occur- 
rence was not produced by a pocket of gas under pressure, why 
was coal burst from the face and from the side of the heading ? 



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826 DISCUSSION — ^THE COUBRlilllES EXPLOSION. 

This was one of the arguments in favour of the theory of a 
pocket of gas. Mr. Lockett's experiences at an adjoining col- 
liery were confined to outbursts of gas, followed by a little top 
coal, and not of coal blown out immediately in advance. The 
floor at the roll was of the usual nature : it was not broken in any 
way, but simply altered in its contour, and the stratification fol- 
lowed along the same lines. Each safety-lamp was intact, when 
found; and it was supposed that each one was extinguished by 
gas or by concussion, either one or both. The safety-lamps 
would be hung up, and the goth might cause them to drop to 
the floor, so extinguishing them, without damage. 

The further discussion was then adjourned. 



DISCUSSION OF MESSRS. W. X. ATKINSON AND A. M. 
HENSHAWS PAPER ON " THE COURRlilRES 
EXPLOSION."* 

Mr. F. H. Wynne asked whether the authors, in the course of 
their explorations, had found any dust-free spaces or dust-safe 
spaces, over which the explosion had passed ; and if so, what was 
the length of these spaces? 

Mr. Edw. B. Wain wrote that as the question of the pro- 
bability of non-inflammable dust limiting a coal-dust explosion 
had been raised, the following notes from a report by Prof. F. A. 
Abel t were of interest. 

The results obtained with this particular dust led me to try whether tho 
ignition by a lamp-flame of a mixture of fire-damp and air, not inflammable joer «e, 
would be brought about by stlspending in it a fine readily-floating dust which was 
quite non-combustible, and not susceptible of any chemical change by exposure 
to a high temperature. The powder answering to these conditions which was most 
readily procurable when this experiment suggested itself, waii calcined magnesia. 
A gas- mixture having 3 per cent, of fire-damp was allowed to pass a lamp-flame at 
a velocity of 600 feet per minute for some time ; no result was produced, but on 
causing it to convey calcined magnesia in suspension long flares of flame were 
produced within a few seconds of the mixture first passing the lamp, and the 
inflammation speedily spread throughout the gallery with feeble explosive effect. 

* Trans, Iwl, M, B,, 1906, vol. xxxii., pages 439, 340 and 507 ; and vol 
xxxiii., pages 124 and 303. 

t Report on the Results of Experiments made loith Samples of Dust collected at 
Seaham Colliery, by Prof. F. A. Abel, 1881 [C.-2923], page 9 ; and Final Report 
of H.M, Commissioners appointed to ijiquire into Accidents in Mines^ 1886 [C. — 
4699], page 156. 



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DISCUSSION — THE COXJERlilRES EXPLOSION. 327 

With only 2*75 per cent, of gas, results quite similar were produced, the general 
ignition following, however, less rapidly after the first production of the flares ia 
front of the lamp-flame. With another sample of calcined magnesia, which was 
not quite so light as the first one, a corresponding result was obtained with a. 
mixture containing 3 per cent, of fire-damp. 

In a still atmosphere, containing 2*5 per cent, of coal gas, one of the most 
sensitive of the Seaham dusts (K), when suspended in it, produced ignition of th& 
mixture, with no explosive effect. A corresponding result was produced by sus- 
pending calcined magnesia in a still atmosphere containing 3 per cent, of gas. 

It will be seen from these results that the perfectly non-combustible powder, 
magnesia, is, in its power to bring about the ignition of an otherwise uninflam- 
mable mixture of fire-damp or coal gas and air, little inferior to the most inflammable 
and sensitive of the Seaham dust-samples. 

These remarkable results led to the trial of a number of other non-combustible 
powders or dusts, which are not chemically affected by such heat as they would be 
exposed to in the flame of a lamp (such as kaolin, powdered flint and other forms 
of silica, pumice, slate dust, etc. ) with results similar to those f urniBhed by the 
magnesia-dust, but more or less affected by variations in the density and other 
physical properties of the dusts. In experiments with currents of 1 ,000 feet velocity, 
the effect of any one of the powders being deposited on the bottom and sides of the 
gallery, was to cause the instantaneous ignition of a 3*5 per cent, gas-mixture on 
its reaching the lamp-flame, through the influence of dust-particles carried along 
by the current, and in some instances a like result was obtained with 3*25 and 3- 
per cent, gas-mixtures. 

Mr. J. T. Stobbs directed special attention to the point raised 
in the paper that some dusts were apparently harmless, when 
containing over 60 per cent, of non-combustible material, such 
as shale or stone-dust. That statement was in direct conflict 
with Sir Frederick Abel's work and the quotation, supplied by 
Mr. Wain, proved that statement. Consequently, Mr. Wynne's 
"dust-safe spaces" was a contradiction in terms, that was to 
say, if any dust was dangerous. 

Mr. F. H. Wynxe replied that, if all dust was dangerous, it 
was a contradiction in terms, but they had evidence in the paper 
of dusty spaces over which the explosion had not continued. 



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528 TUTBUEY GYPSUM-MINES AND PL ASTEE- MILLS. 



THE NORTH STAFFORDSHIRE INSTITUTE OF MINING 
AND MECHANICAL ENGINEERS. 



EXCURSION MEETING, 

HXLD AT TUTBITBT, JUKB 24tH, 1907. 



The members visited Messrs. J. C. Staton & Company's 
^psum-mines at Fauld and plaster-mills at Tutbury, where 
they were met by Mr. T. TrafPord Wynne and shown over the 
works. Luncheon was kindly provided at Tutbury. 

A hearty vote of thanks was accorded to Messrs, J. C. Staton 
& Company and to Mr. T. Trafford Wynne, for their kindness 
in allowing the members to inspect the mines and works. 



TUTBURY GYPSUM-MINES AND PLASTER-MILLS. 

The gypsum-mines of the Dove valley* have been described 
in the Transactions, 

The plaster-mills at Tutbury were originally the corn-mill 
for Tutbury Castle. The whole of the power required on these 
extensive premises is obtained fi-om turbines, the motive power 
being furnished by the waters of the river Dove, conveyed in a 
flume cut in the reign of Henry VII. 

The various grade? of plaster are chiefly accounted for by 
the different qualities of gypsum, but various processes are 
«.dopted in the manufacture. The finest plaster used for artistic 
purposes and various other plasters are made by calcining the 
gypsum in kilns, cleaning it with brushes, and grinding it in 
mills. Ordinary plasters used for mould-making and for 
builders' purposes are made by breaking the gypsum, grinding 
it, and treating it by the process known as ** boiling." This con- 
sists in placing it on circular hearths, heated from below, and 
on these the plaster is continually stirred by mechanical means. 
Keens, Parian and other cements are also manufactured, the 
processes being more or less secret. It may, however, be said 
generally that the gypsum is calcined in kilns, treated with 
<jhemicals, baked and finally ground. 

• "Gypsum, and its Occurrence in the Dove Valley," by Mr. T. Trafford 
Wynne, rrarw. Inst. M. K, 1906, vol. xxxii., page 171. 



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TRANSACTIONS. 829 



THE INSTITTJTION OF MINING ENGINEERS. 



GENERAL MEETING, 
Hku) in the Rooms of the Geological Sogiett, Rublinoton House, London, 

June 13th« 1907. 



Mb. MAURICE DEACON, President, in the Chair. 



PRIZES. 

The Seceetaey reported that the Council had awarded prizes 
of books to the writers of the following papers, which had been 
printed in volumes xxx. and xxxi. of the Transactions: — 

" Mining Fields of Southern Rhodesia in 1905." By Prof. J. W. Gregory. 

** Practical Problems of Machine-mining." By Mr. Sam Mavor. 

" Rescue-apparatus and the Experiences gained therewith at the Courri^res 

Collieries by the German Rescue-party." By Mr. G. A. Meyer. 
*' Description of the Sinking of Shafts through Sand at Ardeer, Ayrshire, by 

the Pneumatic Process, with Notes on the Subject of Caisson-ventilation 

and Sickness." By Mr. T. H. Mottram, 
<' Commercial Possibilities of Electric Winding for Main Shafts and Auxiliary 

Work." By Mr. W. C. Mountain. 
"The Value of Fossil MoUusca in Coal- measure Stratigraphy." By Mr. 

John T. Stobbs. 



Mr. Maurice Deacon read the following " Presidential 
Address " : — 



VOU XXXIII.-1906-1«07- 



25 



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880 PRESIDENTIAL ADDRESS. 



PRESIDENTIAL ADDRESS. 



By M. deacon. 



Before entering upon the subject of my address, I desire to 
thank you for conferring upon me the honour of the Presidency 
of this Institution for the current year, and in doing so I make 
no apologies for any lack of ability to fulfil the office to your 
satisfaction; I can only assure you of the great interest that I 
take in the Institution, and of mj desire to assist in widening 
its influence for the benefit of the profession and of the public at 
large. 

In endeavouring to review the progress which this Institution 
and the profession of mining engineering have made during the 
past few years, I have fully in mind the difficulty of adding to 
the knowledge of the members in any important degree or of 
making any statement of a startling or novel character. I there- 
fore propose to cast a retrospective glance at the history of this 
Institution and of mining engineering during the past quarter 
of a century, coupled with a few suggestions as to the possi- 
bilities of future years. 

This Institution was formed in the year 1889, with the object 
of broadening the sources of information upon matters affecting 
the profession of mining engineering, by amalgamating the 
various mining institutions of the Kingdom into one consolid- 
ated body ; and, with the sole exception of the South Wales 
Institute of Engineers, I believe that this object has been 
attained. 

In the year 1891-1892, there were 1,401 federated members 
and 19 non-federated members, contributing subscriptions 
amounting to £1,060, whilst the working expenses amounted to 
£1,471. In the year 1905-1906, the federated and non-federated 
members respectively were 2,972 and 73, whilst the subscriptions 
amounted to £2,859 and the working expenses to £3,170. This 
great increase of membership, representing over 100 per cent, in 



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PRESIDENTIAI. ADDRESS. 831 

15 years, can only be regarded as satisfaetory, whilst the financial 
results are also satisfactory, representing as they do an increase 
in the subscriptions of nearly 170 per cent, and in the working 
expenses of only 115 per cent., whilst the income from all sources 
of the year 1906 exceeded the working expenses by £368 and a 
cash-balance of £1,907 remained, the highest amount since the 
establishment of the Institution. 

In the year 1905-1906, 64 papers were received by the 
Institution, including 42 from the Federated Institutes. Many 
of these papers contained valuable information, which was 
materially increased by the discussions upon them. 

The previous decision of the South Wales Institute of Engin- 
eers not to amalgamate with this Institution is regrettable, from 
the fact that the profession at large suffers from the absence of 
that free interchange of experience and opinion which is neces- 
sary for its fullest advancement, and which alone can be attained 
by the association of all the mining institutions in the United 
Kingdom. The other allied professions have, I believe, all 
recognized the benefit of the consolidation of their interests, 
with the result that civil engineers, mechanical engineers, 
and electrical engineers, architects, and geologists, have 
each but one Institute, and there is but one Iron and Steel 
Institute. With such an example from the allied professions, 
it would appear that little risk would be incurred in mining 
engineers adopting a similar course, and it is to be hoped that 
the South Wales Institute of Engineers will shortly recognize the 
advantage to themselves and to this Institution, of consolidating 
into one powerful body the two Institutions, in order that the 
fullest advantage from the combined deliberations of mining 
engineers throughout the Kingdom may accrue to the nation. 

Perhaps the most striking advancement during recent years 
is the progress of scientific education. Twenty-five or thirty 
years ago, the facilities for the scientific training of the younger 
members of the profession were extremely meagre, and, in fact, 
it was rarely possible for any person occupying a salaried posi- 
tion at a colliery to acquire scientific knowledge except by the 
reading of books. It is true that the Universities of Oxford, 
Cambridge and London existed, and that some of the large 
qentres of industry had their scientific or technical schools ; but 



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^^2 PRESIDENTIAL ADDRESS. 

these were few and far between, and beyond the reach of the 
majority of young men employed at mines, excepting those who 
could afford to spend two or three years in scientific training 
before commencing practical work. The opportunities for com- 
bining scientific with practical instruction were available in very 
few instances. 

At the present time, the existence of technical schools in the 
heart of every industrial centre brings within the reach of every 
person desiring to acquire scientific knowledge the opportunity 
of doing so, without materially interfering with his daily work. 
The facilities offered to mining students by some of the provincial 
universities of combining scientific education with practical 
mining work has, in my opinion, established the best means of 
training the mining engineers of the future, for the reason that 
the practical work assists the student in the readier comprehen- 
sion of the scientific teaching, and that the scientific teaching 
assists him to comprehend many of the practical problems con- 
fronting him in his daily work, from a scientific standpoint. 

It is natural that professors should prefer the student to 
devote the whole of his time to scientific work for a given period, 
but it is not within the financial reach of many students to do so. 
Personally, however, I am strongly of the opinion that the 
sacrifice of two or three years in the initiation of the student into 
practical work is not calculated to produce the best type of 
mining engineer, to whom the nation must look for the economi- 
cal production of its coal and other minerals in the future. 

In briefly referring to the safe working of our mines, it is a 
source of satisfaction to note the improvement which has taken 
place in the diminution of fatal accidents in relation to output 
and to the persons employed. 

In the year 1882, the output of coal in the United Kingdom 
was 156,499,977 tons, whilst in 1906 it amounted to no less than 
251,067,628 tons, which is equivalent to an increase of 61 per 
cent. In the same years, the persons employed in and about the 
coal-mines in the United Kingdom were 503,987 and 882,346 
respectively, representing an increase of 76 per cent., whilst the 
loss of life was 1,126 and 1,142 respectively, an increase of only 
IJ per cent. The average loss of life for the 10 years ending 
December 31st, 1882, was 1,129, and the death-rate per 1,000 



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PRESIDENTIAL ADDEESS. S38 

persons employed was 224, and 7*42 per million tons of coal 
raised; whilst in 1906 the parallel figures were 1*29 and 4*31 
respectively. Such figures as the foregoing can only be regarded 
as highly satisfactory, and as the result of the more careful 
management of our mines. Nevertheless, every colliery manager 
and mining engineer will continue to direct his best efforts to the 
still greater reduction of accidents. To what further extent the 
death-rate may be reduced probably depends more upon the care- 
fulness of the men themselves than upon colliery managers, since 
the principal sources of accident are such as are mainly under 
their control. The deaths from falls of roof and sides in 1906 
were no less than 551, or nearly 50 per cent, of the total loss of 
life from all causes ; whilst 214 were due to haulage accidents, 
the greater part of which might probably have been avoided by 
the exercise of reasonable care on the part of the victims. It is 
a matter for congratulation to every person connected with 
mining and to the public at large, that the loss of life from 
explosions of fire-damp was reduced to the low figure of 65 in 
1906, or under 6 per cent, of the deaths from all causes, as com- 
pared with an average of 263 deaths for the ten years ended 
December Slst, 1882, which was equivalent to 23 per cent, of 
the average total deaths over that period. 

Many and various suggestions have been made by mining 
engineers, giving evidence before the Royal Commission on 
Mines, with regard to the safer working of our mines, the most 
prominent relating to methods of attempting to arrest the exten- 
sion of explosions by the aid of coal-dust. Without attempting 
to criticize the evidence which has been given, it may be stated 
that the watering of the roadways in and around the points where 
shots are to he fired must be recognized by all as necessary in 
dusty mines. Whether the watering of the whole of the main 
roads can be economically carried out, having regard to the effect 
of water upon certain floors, roofs and sides, is very doubtful, and 
it may be safely stated, in view of the varying conditions of mines, 
that no general rule applicable to all mines in the Kingdom can 
be wisely made. 

Whilst dealing with the death-rate from accidents in mines, 
it may be interesting to refer to the comparative mortality in 
other occupations, both from accidents and from all causes. 
The latest published returns of the Registrar-general are for the 



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384 



PRESlDEJfTlAL ABDttESS. 



years 1890 and 1892, and for this purpose it will be sufficient to 

give a very short abstract of the mortality in a few of the principal 

occupations during those years (Table I.). It is clear that the 

Table I.— Mean Annual Dbath-rate per 1,000 Living engaged 
IN Various Ocx3Upation& 







A«ed 


Aged 




Aged 


Aged 


Oooupatioiu. 




25to46 


45 to 66 




25 to 45 


45 to 65 






Yean. 


Tears. 




Years. 


Years. 






Percent. Percent. 




Per era t. 


Percent. 


Sawyers 


..* 


7 04 


23-91 


General labourers, London 14*76 


38-14 


Garriage-maken .. 




8-86 


30-74 


Ironstone-miners 


7-00 


22-02 


Wheelwrights ... 




6-66 


24-48 


Tin-miners 


10-41 


46-59 


Ship- Wrights 

Wool and worsted d 




7-11 


2001 


Stone and slate quarries . . 


10-75 


34-62 


aanu- 






Coal miners: — 






facture 




9-08 


29-37 


Durham and Northum- 






Cotton, flax and 


linen 






berland 


6-60 


23 07 


manufactare ... 




9-39 


3411 


Lancashire 


8-63 


31-55 


Laoe-manufacture 




6-63 


21-18 


West Riding of York- 






Hosiery-manufacture 




7-23 


20-89 


shire 


7-20 


26-46 


Paper-manufacture 




7-18 


2775 


Derbyshire and Notting- 






Potters, etc. 




12-98 


52-78 


hamshire 


5-98 


21-41 


Glass-manufacture 




1411 


40-83 


Staffordshire 


719 


30-28 


Bailway platelayers 


and 






Monmouthshire and 






railway labourers 




10-52 


30-41 


South Wales 


9-90 


33-27 


Costermongers, hawkers . 


19-65 


42-10 


All males 


9-99 


28-30 


Note.— The Report! 


>f the Eight Hours' Day Departmental Committee stated 


that in the 10 years 


from 1890 to 1892 ai 


id 1900 to 1902 the mortality of all coal- 


miners had decreased 20*8 


per cent. , and all other *' occupied males " 


16-1 pel 


•cent.* 



occupation of the miner is not of an unhealthy character, and 
that it compares favourably with most other occupations (having 
regard to the fact that the death-rate from accidents exceeds that 
of many of the other occupations) and with the average of " all 
males." Any opinions which may have been formed by those un- 
acquainted with the working conditions of the British coal-miner's 
life, to the efEect that the occupation is unhealthy as compared with 
other occupations, may therefore be banished from their minds. 

During the year 1906, three important Acts of Parliament 
affecting the mining industry were passed, namely, the Work- 
men's Compensation Act, the Trade Disputes Act and the 
Census of Production Act. By the first-named Act a further 
burden will be placed upon coUieiy owners and the public from 
July 1st next. The extent to which this Act will affect the cost 
of production remains to be seen, but that it will be greatly 
increased is indisputable, and this is evidenced by the largely 
increased premiums that insurance companies are demanding 
upon their present scales. 

Among other items of le^slation in regard to the working of 

* Final Report of the Departmental Committee appointed to inquire into the 
ProhaUe Economic Effect of a Limit of Eight Hours to the Working Day of Coal- 
miners, 1907 [Cd. 3605], part i., page 48. 



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PBESIB£NTIAL ADDEESS. 885 

mines, tke following bills kave been promoted in Parliament, 
namely, the Coal-mines Regulation Bill, Engines and Boilers 
(Persons in Charge) Bill, and two Bills for limiting the period 
of working underground. The proposal to disturb again the Coal- 
mines Regulation Act (which has had but a short period of exist- 
ence, and during which a marked improvement in the death-rate 
from accidents has occurred) appears to be unnecessary and un- 
desirable, and likely to introduce fresh difficulties in the manage- 
ment of our mines, coupled with an increased cost of production. 
The proposals of the Coal-mines (Eight Hours) Bill is fraught 
with serious danger, not only to the industries of the country and 
to the public at large, but to the very men in whose supposed 
interests the promoters introduced their Bills. At the present 
time, few miners work over 8 hours in one day, and this cannot be 
regarded as excessive, in view of the fact that the average number 
of days worked per week over the whole country is less than five. 
By the passage of such an Act, the time available for coal-work- 
ing would in many cases not exceed 6 hours per day, and in those 
mines where the working-face is situated a very long way from 
the pit-bottom, probably not more than 5i hours. The effect of 
such a serious limitation, apart from the injustice to the industri- 
ous workman anxious to make provision for the future comfort of 
himself and his family, would be to increase the cost of produc- 
tion so seriously that those industries which are of necessity large 
consumers of coal, especially the iron and steel trades, would be 
seriously prejudiced in competition with foreiign countries, to 
the grave detriment of the trade of the country generally ; whilst 
the household consumer, and especially the poorer class, would 
suffer great hardship by the increased cost of fuel for house- 
consumption. To what extent the price would rise, it is, of course, 
impossible to suggest, but that a reduction of 20 to 25 per cent, 
in the output, which would probably accrue, would result in a 
great scarcity of coal, tind that such a scarcity would result in 
a great rise in the price, cannot be questioned. In an experi- 
ment made some years ago to test the practical result of such a 
limitation of hours of working, I found that the output of a 
certain colliery was reduced by 27 per cent, below the output 
obtained on a normal day of 9 hours' winding. It is, therefore, 
to be hoped that the Legislature will refrain from entering upon 
a step pregnant with such serious results to all sections of the 
community. 



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836 PEESIDENTIAL ADDRESS. 

With regard to future legislation, it appears desirable in tke 
interests of lessees and of the country at large that the power of 
a mineral-owner to decline to lease or sell his coal, in the case of 
small areas, upon reasonable terms, where such refusal would 
result in the coal remaining unworked, and the withholding of 
wayleave-rights or the imposition of unreasonable terms for such 
rights, should be dealt with by Parliament. 

Whilst on the subject of legislation, it may be interesting to 
allude to the important question of the right of a surface-owner 
to support of the surface. It is now well known to every mining 
engineer that, where the ownership of the surface is separated 
from the ownership of the minerals, fhe minerals may not be 
worked so as to let down the surface except by consent of the 
surface-owner. It is not, however, generally known that an 
action is pending in the courts in which the right of the lessee to 
let down the surface, where both the surface and the minerals 
belong to the same lessor, is being challenged, notwithstanding 
the fact that by a provision in the lease it is set out that the coal 
shall be worked by the longwall method. If this claim be up- 
held by the courts, it may be stated without contradiction that 
the majority of the leases now existent will be of value to the 
lessees only by the goodwill of the lessors. Many old leases con- 
tain no specific power to let down the surface, but in yiew of 
recent aad possible future judgments, no new leases should *be 
made without such a provision. 

The improvement in the working of collieries during the 
past twenty-five or thirty years has not been confined to the 
great and satisfactory diminution in the number of accidents in 
relation to the output of coal. Considerable progress has 
been made in the economical working of coal by the adoption of 
the longwall system in those districts where the pillar-and-stall 
method was to a large extent in operation, whereby economies in 
working, improved ventilation, and the more complete extraction 
of the coal have taken place, whilst the proportion of small coal 
to large has been considerably reduced. 

Great progress has been made in the mechanical engineering 
of collieries, the development of perhaps the most striking 
prominence being, the use of electric power. Twenty years ago 
it was considered by mining engineers and colliery managers a 



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PRESIDENTIAL ADDRESS. 387 

dangerous expedient to use electric current in the underground 
workings of fiery mines, and even within the past 10 years it 
haa been so regarded in South Wales. The adoption of the 
alternating current, the use of enclosed motors, oil-immersed 
switches and fuses, and the encasing of cables or burying them in 
the floor, have, however, gone far to remove the fears which then 
existed, with the result that it is now generally admitted that this 
useful method of transmission of power for hauling and pumping 
may be adopted with safety in most mines. Its application for 
haulage purposes, not merely on the main roads, which in itself 
is frequently a matter of economy and convenience in the case of 
deep shafts, but particularly to auxiliary ropes employed for the 
purpose of feeding the main ropes, has done much to reduce the 
cost and increase the efficiency of the conveyance of coal from 
the working-face to the pit-bottom. 

In seams which are worked to the dip, it is now a common 
practice to employ mechanical haulage to the entire exclusion of 
horses ; and, in Warwickshire, where several seams are worked in 
conjunction with one another and brought to one main gateroad, 
it is the custom to employ a small haulage-set on every gateroad, 
as well as on the subsidiary levels or cross-gates. 

In underground pumping, where small volumes of water 
require to be pumped at various points in the workings, great 
economy has been effected, as well as in the case of small shaft- 
pumps of the three-throw, high-speed, or centrifugal types. 

By the use of steel props and girders, economies have been 
effected in some mines of fully Id. per ton upon the ooal raised, 
and there is little doubt that their use might be adopted and 
extended in many mines with successful results. Making allow- 
ances for breakages and losses in an average mine, the average 
life of steel props varies from 10 to 13 years ; whilst in the same 
pit it is not unusual to find that the life of a wooden prop, even 
when re-set time after time, and ultimately cut up for sprags 
and lids, does not exceed three months. 

Electric coal-cutting machines have been largely adopted in 
recent years in seams of varying thicknesses and conditions. 
Considerable economy has arisen, both in the case of getting the 
coal and in the reduction of the proportion of small coal, conse- 
quent upon much of the holing being performed in the clunch 
or under-clay. The economy so effected may be roughly stated 
to vary from 3d. to Is. per ton, according to circumstances. 



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388 PEESIBEKTIAL ABD&ESS. 

The use of belts for conveying the coal along the working- 
face to the gate-ends has been successfully adopted in some thin 
seams, where the height is insufficient to permit of an ordinary 
tram being loaded. 

Heading machines, by which as much as 108 feet of coal- 
heading per week has been cut, have also played an important 
part in the economical working of those thick seams where it is 
necessary to fore-win the coal, and for heading through shaft- 
pillars. These machines, which were until recently driven by 
compressed air generated on the surface, whereby great loss 
of power was involved by loss of heat and friction in the pipes, 
are now frequently actuated by electrically-driven portable high- 
speed compressors placed near to the machines and moved forward 
as the headings progress, thus avoiding the loss of a considerable 
amount of power in transmission, and providing a cheaper means 
of carrying the power to the machines. 

The improvement in the surface mechanical equipment of 
collieries has been still more marked. The egg-ended boiler, 
with its accompanying steam-pressure seldom exceeding 50 or 
00 pounds per square inch, and having' evaporative powers of 200 
to 300 gallons of water per hour and a duty frequently not exceed- 
ing 5 pounds of water per pound of fuel consumed, has given 
place to the Lancashire boiler, working at pressures varying 
from 100 to 160 pounds per square inch and having evaporative 
powers- of 800 to 1,000 gallons and upwards per hour, whilst the 
duty may be roughly stated to be 8 to 9 pounds of water evapor- 
ated per pound of fuel consumed. In cases where the water has 
been found suitable, water-tube boilers, with working-pressures 
up to 200 pounds per square inch have been adopted to a con- 
siderable extent, with successful results, both as regards high 
evaporative power, economy in fuel, rapidity of steam-generation , 
and limitation of space. As an instance of the perfection to which 
the economical evaporation of steam may be brought, a Babcock- 
and- Wilcox boiler, fitted with a chain-grate stoker, a superheater 
and an economizer, gave an over-all efficiency of 88 per cent, 
compared with the efficiency of an ordinary Lancashire boiler, 
without an economizer or a superheater, of 60 to 65 per cent. 

By the use of induced draught, high chimneys have, in some 
cases, been avoided, greater evaporative powers obtained from 
boilers, and inferior fuel consumed. 



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PKESlDENTIAIi ADD&ESS. 839 

By the use of higher-pressure steam, coupled with more 
economically designed engines ; by the greater use of expansion 
gear ; and sometimes by superheating and condensing, the steam- 
consumption of modem collieries has been greatly reduced. 
Winding-engines, which fonnerly consumed 70 or 80 pounds of 
steam per indicated horsepower, may now be found using not 
more than 30 pounds of steam; whilst continuously-running 
engines and steam-turbines, such as are commonly used for fan 
and electric driving, are in some instances working with not more 
than 14 or 15 pounds of steam per indicated horsepower. The 
numerous smaller engines necessary in the past for driving screen- 
ing-plants, workshops, shaft-pumps, and for other purposes, 
have been superseded in all modern collieries by the use of 
electric motors, thus avoiding long ranges of steam-pipes and the 
accompanying loss from radiation and condensation, which were 
visible at every colliery not many years ago. 

As an instance of extreme economy in the production of power 
with inferior fuel, the plant erected by the SchwartzkopfE Coal- 
dust Firing Syndicate, adjoining the Haydock collieries of 
Messrs. Richard Evans & Company, Limited, is well worthy of 
notice. The fuel, consisting of the finest dust produced on the 
colliery-screens and further ground in a mill to an impalpable 
powder, is introduced into the furnace of a water-tube boiler by 
means of a revolving brush, and is there consumed as a gas. 
The engines are of the triple-expansion high-speed type, con- 
densing, and the steam is superheated to a high degree. The 
steam-consumption is said to be 9 pounds per indicated horse- 
power, and the duty of the boiler is 9 pounds of water evapor- 
ated per pound of fuel. Here is an instance of extremely low 
fuel and steam-consumption ; but, on the other hand, the capital 
outlay and the cost of repairs to the mill, operate as a heavy 
counter-balance to the low fuel-cost. 

Considerable attention has been paid by mining engineers of 
late years to the treatment of impure water to be used for boiler 
purposes. There is perhaps no greater necessity in connection 
with the working of a colliery than the provision of pure boiler- 
water, by which the fuel consumed and the labour, together with 
the cost of repairs, may be reduced to the lowest possible point. 
In view of the extremely low cost, which varies from |d. to 2d. 
per 1,000 gallons of water purified, it is somewhat astonishing to 
find that this easy source of economy is not more generally 



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840 PRESIDENTIAL ADDEESS. 

adopted where bad water exists. Where sufficient condensing 
water is available, surface-condensing has been in many cases 
adopted, whereby the advantage of the use of pure boiler water, 
eotipled with the economy of a vacuum, has given excellent 
results. Objection may be raised to the use of surface-con- 
densers when the water forms considerable scale in the tubes; 
but this may, in many instances, be overcome by the occasional 
application of a weak solution of muriatic acid. 

These various improvements have led to great economy in 
fuel, with the result that whereas the old-fashioned colliery (not 
being heavily watered) frequently consumed from 6 to 10 per 
cent, of its output in raising steam for the working of the colliery- 
engines, the well-designed colliery of recent date may be found 
to be working with a consumption as low as 2i per cent, of the 
output. 

An economy of such magnitude is not merely of vital im- 
portance to the colliery owner, but to the nation at large : for not 
only is the cost of production thereby decreased to an important 
extent, but the coal which, under the old practices, would have 
been wasted is preserved for the performance of useful work. 
AVhen it is borne in mind that the annual output of coal in the 
United Kingdom has reached the enormous total of 251,000,000 
tons, it is apparent that the coal-reserves of the country will be 
economized to an important degree when, in the course of years, 
the old-fashioned colliery machinery has been superseded by the 
more economical appliances adopted at modern collieries; for, 
an economy of 2^ per cent, only on the output of 1906 would 
represent no less than 6,275,000 tons of coal saved in one year. 

In connection with this important subject, the better utiliza- 
tion of the calorific value of our fuels by the use of gas-producers 
and gas-engines has received and is receiving considerable atten- 
tion. It is a well-known fact that the effective utilization of the 
calorific power of fuel by this means is about five times as great 
as when the same fuel is used under steam-boilers. The result 
obtained from plants of this description which have been running 
for many years, shows that a consumption of 1 pound of small 
coal or slack will pro<luce 1 indicated horsepower in a gas- 
engine when running on full load; whereas the quantity of 
the same fuel used in a boiler for steam-raising would probably 



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PRESIDENTIAL ADDRESS. 841 

be not less than 4 or 6 pounds, taking into account the losses by 
radiation and condensation. At a colliery in Yorkshire, a plant 
of this description has been provided for the purpose of utilizing 
the bats picked out at the screens. These bats, containing 18 per 
cent, of ash, yield 153,000 cubic feet of Mond gas per ton, having 
a calorific value of 146 British thermal units per cubic foot, and 
the waste-gases are used for heating the boilers of the colliery. 
The capital cost of a combined Mond producer, gas-engine and 
electric plant of 250 to 500 kilowatts may be taken approximately 
at £25 per kilowatt and the working cost at 0'4d. to 0"5d. per 
kilowatt-hour, including 10 per cent, for interest and deprecia- 
tion on capital-outlay, and with fuel charged at 8s. 6d. per ton 
at the producers. In the case of plants of 1,000 kilowatts and 
upwards, working costs as low as 0'15d. per kilowatt have been 
obtained. The economy in fuel in such plants is admittedly 
great; but the additional capital-outlay, as compared with 
modem high-class steam-engines, detracts to a large extent from 
the apparent economy, necessitating careful consideration before 
deciding to depart from the use of the well-known and proved 
steam-engine. It need hardly be mentioned that the use of gas- 
engines will necessarily be confined to the supersession of engines 
other than winding-engines, except in those instances where the 
distribution of electric power to several winding-shafts may 
render the adoption of electric winding economical. 

In those cases where the fuel is rich in nitrogen and of a non- 
cokingi character, the abstraction of the sulphate of ammonia and 
tar, plus the utilization of the surplus gases, may fully warrant 
the greater capital-outlay. Further, the result may, in the case 
of fuel of this character, not only be the production of the steam 
required for colliery purposes without the need of coal-firing; but, 
in addition, the possible sale of surplus gases and the revenue 
to be obtained from the sale of the bye-products. By the gas- 
producer, not only may the fullest calorific value be obtained 
from good coal, but waste-heaps, containing a large propor- 
tion of bituminous matter, will probably be more or less utilized 
in the future. 

Suction-gas plants have made considerable headway in recent 
years. They may be very conveniently adapted to small isolated 
purposes and controlled by one man. The working cost of small 
plants of this class, inclusive of fuel (anthracite-nuts), stores, 



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842 PKBSIDENTIAIi ADDRESS. 

labour and repairs^ but exclusive of interest on capital and 
depreciation, may be taken to be about 0"2d. per indicated horse- 
power and the fuel-consumption at 1 pound per indicated horse- 
power. This is a great advance upon the results of the Cornish 
pump, the most economical of our old-fashioned engines, with a 
consumption of 3 to 4 pounds of good Welsh coal, and this result 
is hard to beat where large volumes of water require to be 
pumped from considerable depths. Various developments have 
been made in heavy pumping-engines of late years, but no marked 
economy in steam-consumption appears to have been gained in 
this class of engine. 

The progress in coking and bye-product abstraction from the 
small fuel produced at many collieries has caused a far more 
valuable result to be obtained from fuel, which, not many years 
ago, was regarded as of little or no value. Thanks to our Con- 
tinental neighbours, the beehive coke-oven is fast becoming ex- 
tinct in favour of the retort-oven. The revolution which has 
taken place in this direction has not only been the means of 
utilizing, to a far greater extent than heretofore, a considerable 
proportion of our national wealth, but, at the same time, in many 
instances, has enabled collieries, the economic conditions of which 
rendered it difficult for them to exist in the past, to be transformed 
into profitable concerns, owing to the larger yield of coke per 
ton of fuel used, together with the value of the residuals, forming 
as they do, in many instances, a greater source of revenue than 
the coke itself. The objection originally raised to the use of 
retort-oven coke is rapidly dying out, and it is perhaps not going 
too far to say that with care on the part of the coke-burner as 
regards the percentage of water that he sends away in the coke, 
this objection will disappear altogether : for the reason that the 
density of retort-oven coke when properly burnt is generally 
greater than that of beehive coke, and it is consequently capable 
of carrying a heavier burden in the blast-furnace, a circum- 
stance highly prized by the blast-furnace manager. The 
utilization of the surplus gas from regenerator-ovens forms 
another source of profit from this process, supplying, as it fre- 
quently does, power for driving electrical plants, aiid in some 
cases for the lighting of the colliery-premises and adjoining 
villa^s, 



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PKESIDENTIAIi ADDRESS. 843 

Tho careful consideration of economies in fuel for colliery- 
purposes becomes increasingly important, by reason of the greater 
depths from which the coal of the future will of necessity be 
wound. The question of raising large quantities of coal from 
depths of 2,600 to 3,000 feet, which will have to be confronted 
on a large scale at an early date, opens up a fresh field for the 
exercise of the ingenuity of the mining engineer. In the case 
of collieries sunk to such depths, where only one workable seam 
is available, very large areas, probably not less than 18 to 20 
square miles to each pair of pits, will be necessary, to warrant 
the heavy capital-expenditure entailed in sinking and equipping 
plants of the magnitude that will be necessary to raise the 
large quantities of coal required to produce a low cost and enable 
a reasonable return to be made upon the large capital involved. 

In order that large daily outputs may be raised from such 
depths, the winding-engines and the accompanying plant will 
necessarily require to be of great capacity and powerful construc- 
tion, so as to withstand the strain of the heavy loads and rapid 
winding. The difficult question of the increasing weight of 
winding-ropes, to cope with the greatly augmented loads in deep 
shafts, will occupy much of the colliery manager s and the rope- 
maker's attention. The difficulty of providing a capel of equal 
breaking-strain to a rope of large diameter has fortunately been 
solved by the use of white metal run into the capel. Tho old 
method of capping, by means of hoops shrunk on to the cap, 
fails to give a resistance exceeding 76 or 80 tons, and this is 
obviously useless in the case of a rope with a breaking-strain of 
160 to 200 tons. Loads of fully 25 to 30 tons will have to be 
lifted by one rope, if large outputs are to be obtained from the 
deep pits of the future, unless the expedient of winding in two 
lifts be adopted. Ropes of large diameter, composed of high 
tensile steel, will require to be used; and, with white-metal 
capping, there seems to be little fear of obtaining a capel equal 
to the breaking-strain of any rope which is likely to be put 
into use. 

The question of the ventilation of the larger areas of work- 
ings, accompanying the more extensive mines of the future, and 
the greater volumes of air that will be required, will necessarily 
command the careful consideration of the mining engineer of 



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844 PRESIDENTIAL ADDBESS. 

the future. Amongst other problems, it will be part of his 
business to decide whether it will be more economical and effi- 
cient to provide specially large air-ways or to adopt higher water- 
gauges. On the Continent, the practice has generally been 
followed of substituting high water-gauges for large airways. A 
good example of this appears in the case of the Neumtihl colliery, 
where, I am informed, a Capell fan is producing 328,000 cubic 
feet of air per minute, at 15'8 inches of water-gauge, and an 
expenditure of over 1,000 horsepower in the steam-engine and 
816 horsepower in the air. It appears to be highly improbable . 
that such excessive water-gauges will be required in the mines of 
this country ; but it is not improbable that higher water-rgauges 
than those at present employed will be found to be more econom- 
ical than the maintenance of great lengths of very large air- 
ways. 

The improvement in screening-plants of late years has gone 
far to reach the point of perfection ; and it is difficult to imagine 
that any great advance will be made in the methods of coal- 
sorting, except in the generalization of the practice of washing 
the smaller sizes of coal. In all new plants, where circumstances 
will permit, the screens will no doubt be placed at such a distance 
from the downcast-shaft as will render the impregnation of the 
intake-air with coal-dust from the screens practically impossible. 

Before concluding this brief attempt to review the recent 
and prospective advancement in the engineering of collieries, it 
will be appropriate to say a few words with regard to the improve- 
ments which have taken place in the social condition of the miner 
during the past twenty-five years. In those days, colliery-cot- 
tages (many of which still remain) were frequently huddled 
together near the colliery, where they had little air-space sur- 
rounding them. The architect's skill and taste displayed in 
their design wa« not of a very high order, and the general effect 
was not calculated to arouse in the British miner and his family 
that respect for home which is conducive to cleanliness and respect- 
ability. The opportunities for obtaining rational recreation 
and mental improvement were few and far between, and the 
public-house not infrequently formed the only place where any 
kind of social intercourse could be procured. To-day, another 



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DISCUSSION — ^PRESIDENTIAL ADDRESS. 845 

condition of things exists at nearly all modem collieries and at 
many old ones, where brighter and more picturesque houses, 
'with ample air-space and gardens of a greater or lesser extent, 
are found to exist; houses which will enable the miner and his 
family to live a more healthy and brighter life than in the past. 
Workmen's clubs or institutes, providing rational means of 
recreation and amusement, coupled with the opportunity of 
mental improvement by means of libraries and lectures, and the 
reading and discussion of papers relating to matters of interest 
to the working-man, are now to be found in connection with 
many old and new collieries. Such institutes afford a means of 
gradually improving the social life of the miner and those 
associated with colliery-work; and, if judiciously supervized by 
the resident colliery manager and his subordinates, can only 
result in a feeling of greater respect and confidence between 
the one and the other class. Whilst it may bo said by some that 
this subject does not come within the category of mining engin- 
eering, it can hardly be argued that it does not form a very 
important part of the management of a colliery ; for it is mainly 
by such consideration and attention that it may be possible to 
lift the miner to a social level commensurate with his intellect 
and his means. 

In conclusion, I desire to thank you for the time which you 
have so kindly and patiently devoted to the hearing of this some- 
what long, and I fear uninteresting, address. 



Mr. Emebson Bainbridge, in moving a vote of thanks to the 
President for his interesting and excellent address, said that he 
had avoided superficial treatment in every department of min- 
ing, and had illustrated his address with figures which made it 
unusually practical. Mention had been made of the Trade Dis- 
putes and the Workmen's Compensation Acts, and there was also 
a wise reference to the danger of over-legislation for mines. The 
address was an interesting and practical summary of all that 
was involved in modem mining. 

Prof. A. LuPTON, M.P., in seconding the vote of thanks, said 
that the addrees embodied the results of great and carefully 

▼OL. ZZZm^lMSOMT. 26 



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346 DISCXTSSIOK — PRESIDENTIAL ADDBESS. 

gathered experience, and would be a guide for the younger 
members. He was particularly gratified at the reference to the 
reduction of the death-rate in mines, a matter in which The 
Institution of Mining Engineers had had a very considerable 
share. 

The vote of thanks was cordially adopted, and was briefly 
acknowledged by the President. 



The meeting then divided into two sections for the read- 
ing and discussion of papers. Mr. Maurice Deacon (president) 
presided over one section, and Mr. W. G. Phillips (vice-president) 
over the second section (in the rooms of the Royal Astronomical 
Society, Burlington House). 



Mr. H. B. DE Salis' paper on " Improvements required in 
Inland Navigation " was read as follows : — 



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IMFSOYEMENTS BEQITIRED IN INXAND NAVIGATION. 847 



IMPROVEMENTS REQUIRED IN INLAND NAVIGATION. 



By henry RODOLPH DE SALTS, Assoc. M.Inst.C.E. 



The author proposes, in the following paper, to record his 
views on the improvements required in inland navigation in this 
country, from the experience obtained from his association 
with Messrs. Fellows, Morton & Clayton, Limited, canal carriers, 
as a director for 10 years ; and from having made a personal inspec- 
tion of the whole of the inland navigations of England and Wales, 
amounting to a mileage travelled on waterways of over 14,000 
miles, for the purpose of collecting the information contained in 
Bradshaw^s Canals and Navigable Rivers of Englamd and Waies.* 

In the first place, there often appears to be considerable un- 
certainty as to the extent of the navigable inland waterways of 
England and "Wales, and more than once the author has heard 
the figures contained in the Railway and Canal Traffic Act, 
1888: Returns made to the Board of Trade in respect of the 
Canals and Navigations in the United Kingdom, erroneously 
quoted as being a complete summary of the whole of them. 
This is far from being the case, although it is extremely difficult 
to define exactly what may be considered as " inland navigation.'* 

The total mileage of the waterways described in tte author's 
Bradshaw^s Canals and Navigable Rivers of England and Wales 
amounts to 3,915 miles, comprizing 3,073 miles non-tidal and 
842 miles tidal ; and he considers that the above total is a fair 
representation. The Board of Trade returns for 1898 only show 
a total mileage for England and Wales of 3,167 miles, and do 
not apparently take into account amongst others such water- 
ways as : — The river Arun ; the river Avon (Bristol), the portion 
under the control of the Bristol Docks' Committee; the river 
Bure; the river Colne (Colchester); the Dartford and Crayford 

* Brad8?taw*8 Caruda and Navigable Rivers of England and Wales : A Hand- 
book of Inland Navigation for Manvfacturera^ Merchants, Traders and Others, 
oompUed, after a personal survey of the whole of the waterways, by Mr. Henry 
Rodolph de Salis, 1904. 



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848 



IMPROYEMENTS REQUIRED IN INLAND NAVIGATION. 



Navigation; the river Dee; the river Hull: the river Med- 
way, Hawkwood to Sheemess, 21 miles ; the river Mersey, 
Wamngton to Liverpool, 25 miles ; the river Ouse (Bedford), in 
respect of its direct course from Bedford to the sea, 75 miles, with 
the exception of 2| miles from St. Ives to Holywell ; the river 
Parrett ; the river Boding ; the river Stour (Kent) ; the river 
Tamar; the river Tees; the river Teign; the river Thames, 
below London Bridge, including the navigation of Deptford, 
Bow, Barking and Bainham creeks ; the river Trent, from Gains- 
borough to the mouth, 26 miles; the river Tyne; the river 
Waveney ; the river Wye ; and the river Yare. 



W^ 




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i vA i ^- 



Fig. 1.— Steamer and Bpttt-boat on the Grand Junction Canal. 

The navigable inland waterways of England and Wales may 
be divided, for the purpose of the more easy investigation of 
their condition, into two groups, the first consisting of the main 
system of connected waterways which have inland communication 
with each other; and the second consisting of isolated water- 
ways, or small collections of isolated waterways, which have no 
inland communication with the main system. With regard to 
the waterways of this latter group, the author does not propose 
to say much. They comprize navigations of various sorts and 



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IMI^ROVEM^NTS REQtJIRED IN INLaKD NAVIGATION. 349 

sizes and various deg^rees of prosperity and decay, and partaJke 
more of the nature of local concerns, destined to succeed or fail 
each on its own merits. The author would, however, suggest that, 
in considering any general scheme for the improvement of water- 
communication throughout the country, the question of exten- 
sions to connect some of these isolated groups of waterways with 
the main system might receive attention. 

In considering the waterways of the first group, it will be 
apparent that the condition of each one affects the system of 
water-communication as a whole, and is, consequently, of primary 




Fig. 2.— Steam-launch "Dragon-fly,*' used by the Author, in Wyre 
Lock, on the Lower Avon Navigation, Vi^ARWicKSHiRB. 

importance to trade. The author is not a believer in canal- 
communication for rural or sparsely populated districts, but he 
considers that good water-communication between the principal 
manufacturing centres, the large towns, and the ports, is much 
to be desired. 

Undoubtedly one of the principal causes which have operated 
to prevent the carrying out of improvements in the inland water- 
ways of England and Wales by private enterprise is the excessive 



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850 



IMPROYEMEXTS BEQtJIBED IN INLAND NAVIGATION. 



number, as also lie vajied constitution, duties, interests, and pro- 
cedure, of the numerous authorities controlling them. There 
are canal companies who are carriers, canal companies who are 
not carriers, railway companies, dock companies, boards of con- 
servators, navigation trustees and commissioners, drainage 
trustees and commissioners, local authorities, private individuals, 
and, in some ca^es, no authority at all, in respect of portions of 
navigable waterways. 

It is not surprising, therefore, that among so multifarious 
a collection of authorities charged with so many other 
duties, that the interests of navigation are not always, by any 

means, thefirst con- 
sideration. Hence 
it is that there has 
never been any 
serious movement 
amongst the pro- 
prietors of water- 
ways towards their 
combining to form 
a united system of 
communication. 
There is no "Canal 
Clearing House," 
and (with few ex- 
ceptions) every 
boat-owner has to 
deal separately 
with the manage- 
ment of every navi- 
gation over which 
he trades. Even 
among the independent canal companies forming the through 
routes, there is a great lack of united action ; it is only since 1897 
that the four canal companies, forming the route between London 
and Birmingham, have made arrangements by which through 
tolls can be quoted by the Grand Junction Canal Company, who 
own the largest portion of this route. Such matters as the 
arrangement of times for stopping the canal for repairs, ice- 
breaking, etc., are generally left to the individual action or 
inaction of each company. 




Fio. 3. — Column erected in Ashbidoe Park, 
Hertfordshire, "in Honour of Francis, Third 
Duke of Bridoewater, Father of Inland 
Navigation," 1832. 



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IMPROVEMENTS BEQtJlBED IN tNlAKB NAVIGATION. 



851 



Siinilarly, the ideas of different companies differ widely as to 
what constitutes efficient maintenance ; one company will keep 
the chjannel of its canal fairly dredged, but will possibly neglect 
the towing-path so that it becomes a slough of mire in wet 
weather. Another company will attend carefully to the metal- 
ling and draining of its towing-path and the trimming of the 
hedges, but will allow the channel of the canal to choke with 
mud for want of dredging : this, being under water, cannot be 
seen, although it has a disastrous effect, by increasing the power 
required to haul the boats, and reducing their speed. 




Fig. 4.— Basb of the Bridoewatxb Column, Showing the Inscription. 

If the number of canal companies were reduced, a consider- 
able saving would be effected by the universal use of modem 
plant and machinery for executing repairs and dredging, the use 
of which is at present confined to the larger companies, such as 
the Manchester Ship, Grand Junction, North Staffordshire, and 
Leeds and Liverpool canals. 

On the question of railway-owned canals, the author is of 
opinion that in general railway-ownership of canals is undesir- 
able, as being inimical to canal-development ; but he can hardly 
go so far as to endorse the sweeping assertion that all railways 



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852 



nfi^EOVEMENTS fi,£QtTlR£D IK INLAND NAVIGATION. 



desire to strangle the trade on the canals in their possession. 
In fact, the policy of railway companies towards the canals that 
they have acquired appears to have been, as might be expected, 
exactly what suits them best in each particular case, and conse- 
quently not always the most favourable to canals as a whole. 
One of the largest railway-owned properties, the Trent and 
Mersey canal of the North Staffordshire Railway Company, will 
compare favourably both in condition and in management with 
any independent canal. The Lancaster canal of the London and 
North Western Railway is equally well maintained, whilst among 
others which are quite up to the average may be mentioned the 
Ashton, Peak For- 
est, and Maccles- 
field canals of the 
Great Central Rail- 
way Company. On 
the other hand, a 
railway company 
having originally 
purchased a canal 
as the price of dis- 
arming opposition 
to its line, or of 
extinguishing a 
competitor, it is 
obvious that its 
policy with regard 
to it may not be 
one favourable to 
water-carriage or 
the adjoining canals. In several cases the obligations imposed 
by section 17 of the Railway and C^nal Traffic Act of 1873, as 
regards maintenance in good working condition, appear to be 
a dead letter; but even if the Act is not openly violated, it 
is easy to discourage trade by such means as indifference to 
the requirements of the traders, the imposition of the full 
maximum tolls in all cases, and tbe ordering of frequent 
stoppages for repairs. 

Years ago. Parliament permitted some extraordinary mutila- 
tions of canals by railways, two instances of which may be worthy 




Fig. 5. —Old Pattern of Wooden Drawbridge, on 
THE Wilts and Berks Canal. 



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IMPROVEMENTS REQtIIIlEl) IK INLAND NAVIGATION. 858 

of mention. In 1879, the Monmouthshire Railway and Canal 
Company obtained an Act authorizing them to stop up and fill in 
the mouth of the Monmouthshire canal in the town of Newport, 
thereby severing communication between the Newport docks and 
the canal. In the following year, 1880, the canal wa« acquired 
by the Great Western Railway Company. In the returns made 
to the Board of Trade in respect of the canals and navigations in 
the United Kingdom for the years 1888 and 1898, it appears 
that the Monmouthshire canal was conducted at a loss by the 
Great Western Railway Company, and, under the circumstajuces, 
this is not surprising. In 1845, the Gravesend and Rochester 
Railway and Canal Company purchased the Thames and Medway 
canal, which extended from the Thames at Gravesend to the 
Medway ^at Rochester. The tunnel, which had previously con- 
veyed the canal between Higham and Rochester, was turned into 
a railway tunnel, leaving the canal to extend from Gravesend to 
nowhere in particular. 

Turning attention next to authorities controlling navigable 
rivers, it will be found that, in addition to navigation, they may 
have to consider the prevention of floods, the pollution of the 
stream, and the interests of rowing-boats, sailing-boats, house- 
boats, steam-launches, motor-launches, water-companies taking 
supplies from rivers, riparian owners, fishermen, bathers, etc. 
Sometimes authority is divided, as in the case of the Thames 
above Long Wittenham, where, in addition to the many duties 
carried out by the Thames Conservancy, the Thames Valley 
Drainage Commissioners have a separate drainage-jurisdiction ; 
or, in the case of the Severn, where the towing-path between 
Gloucester and Worcester and again between Worcester and 
Stouiport belongs to two distinct towing-path companies. 

In earlier days, navigation was considerably hampered on 
many navigable rivers, by the control of the water exercised by 
mill-owners. Although many of these water-rights have been 
bought out, some still survive, as on the river Stour (Suffolk), 
and also on the river Stort, where a toll of 6d. for every vessel 
passing through a lock is payable to the occupier of the mill, in 
addition to the ordinary navigation-tolls. Again, in Somerset- 
shire, Lincolnshire, and throughout the large group of waterways 
of the Bedford level and district, nearly all the waterways are 



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354 



nCPBOVEMEHTS KEQUIRED IN INlAHD KAVIGATION. 



primarily maintained for the purpoee of drainage, out of the rates 
leTied on the land by varions bodies of drainage commissioners, 
navigation being, conseqnenUy, qnite of secondary importance. 
In the Bedford level, a large tract of country depends for its very 
existence on its waterways, into which the. surface-water from the 
land is lifted by pumping-engines. In no other part of the country 
is there such a multiplication of authorities crowded together: 
tracing those in respect of the natural channel of the river Ouse 
from Bedford to the sea, they are as follows : — From Bedford to 
Holywell, 33^ miles, the navigation-rights are private property ; 




Fio. 6.— Gbitfin's Lock, Stsoud, on thb Thames and Sevsbn Canal. 

from Holywell to Earith, 5 miles, the river has no controlling 
authority, but the lock known as Brownshill or Over Staunch, 
situated in this length, is maintained by the South Level Drain- 
age and Navigation Commissioners; from Earith to Pope's 
Corner, the junction with the river Cam, llj miles, and known 
as the Old West river, is dredged and kept open by the South 
Level Drainage and Navigation Commissioners, but the Bedford 
Level Corporation cut the weeds and are the owners of the lock 
at Earith called Hermitage sluice. From Pope's Corner through 



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IMPROVEMBNTS REQITlBfD IN INLAND NAVIGATION. 855 

Ely to Littleport Bridge, 9J miles, the river is under the juris- 
diction of the South Level Drainage and Navigation Com- 
missioners. From Littleport Bridge to J mile above Denver 
sluice, 10 miles, the river has no controlling authority. From J 
mile above Denver sluice to the commencement of the Eau Brink 
cut, 10 miles, the river is under the jurisdiction of the Denver 
Sluioe Commissioners. ' Denver sluice was built by the Bed- 
ford Level Corporation, who own the site and appoint the 
sluice-keeper; the Denver Sluice Commissioners maintain the 
fabric of the sluice and all the sea-doors (gates), while the 
South Level Drainage and Navigation Commissioners maintain 
the navigation-doors (gates). From the commencement of the 
Eau Brink cut to its termination, 3 miles, the river is under the 
jurisdiction of the Conservators of the Ouse Outfall. From the 
termination of the Eau Brink cut to the mouth of the river, abo]it 
4 miles further, the jurisdiction is that of the King's Lynn Con- 
servators. Again, the haling- ways (towing-paths) between Denver 
sluice and King's Lynn are under the jurifldiction of the Ouse 
Haling-ways Commissioners ; and the banks of the river between 
Denver sluice and the commencement of the Eau Brink cut are 
under the jurisdiction of the Ouse Banks Commissioners, and 
are divided into six districts. It is interesting to note that, 
throughout the Bedford level, doubtless on account of the Dutch 
origin of the works of drainage, in matters relating to inland 
navigation the district appears almost as a foreign country. Not 
only are the boats (called fen-lighters) and the method of work- 
ing them chained together peculiar to the district, but in addi- 
tion there exists an almost entirely different vocabulary of terms 
respecting river and canal navigation from that used in any other 
part of the country. 

Having now rapidly reviewed the controlling authorities in 
respect of the navigable waterways of England and Wales, the 
author submits that one of the first steps to be taken in the direc* 
tion of reform is to reduce greatly their number, and to deprive of 
all navigation-jurisdiction those authorities that are adverse or in- 
different to the development of navigation. The author thinks 
it desirable that the State should control such of the waterways 
as could be made useful, or, say for instance, the main routes, 
leaving branches and feeders as at present, so that long-distance 
traffic might be administered by one authority. 



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856 



IMPROVEMENTS EEQtIIRED IN INLAND NAVIGATION. 



Passing on to consider the present condition of the waterways 
of England and Wales, the author will examine that of the 
main system of connected waterways. There is nothing in it 
approaching the uniformity possessed by the railway system with 
its universal gauge, interchangeable rolling stock, and arrange- 
ments for forwarding and receiving traffic to and from the lines 
of other companies. The waterways differ widely in character, 
and may be arranged in three principal classes as follows : — 

(1) Canals, being waterways constructed solely for the pur- 
pose of conducting traffic, and affording still water for the passage 




Fig. 7.— Lancasteb Aqueduct, over the River Lune, on the LancasterJ 
Canal op the London and North-western Railway Company. 

of craft in either direction. Setting aside, for the moment, the 
Manchester, Gloucester and Berkeley, and Exeter ship-canals, 
the gauge of the canals varies from that of narrow-boat canals, 
admitting narrow boats measuring 72 feet in length and 7 feet 
beam, with a draught varying from 2 feet 6 inches to 4 feet, up 
to that of the Aire and Calder navigation, and the newly con- 
structed Aire and Calder, and Sheffield and South Yorkshire 
junction canals, which have locks giving a capacity of 120 feet 
by 17 feet, and a draught of water of 7 feet 6 inches. 



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IMPROVEMENTS REQUIRED IN INLAND NAVIGATION. 



857 



(2) Upland rivers made navigable by the provision of locks 
and weirs, which have, usually, a stream flowin-g downwards 
with a velocity, say, up to 3 to 4 miles an hour. As in the case 
of the canals, the gau^e of the locks of the upland rivers varies 
considerably. The river Soar, which forms for the most part 
the Leicester and Loughborough navigations, admits craft 
measuring 72 feet in length and 14 feet beam, with a draught of 3 
feet 6 inches, while the locks of the river Weaver measure 229 
feet in length and 42 feet 6 inches in width, and will admit, at one 
time, four vessels of the ordinary type using the river : these are 
90 feet long, 21 feet beam, and draw 10 feet 5 inches of water. 




Fig. 8. 



-Beablet Aqueduct, on the Stratford Canal of the 
Great Western Railway Company. 



(3) Tidal rivers and estuaries, where rough water is at times 
encountered, and where the tide ebbs and flows often with «i 
considerable velocity, which may, as in the case of the Severn 
estuary, amount to as much as 12 knots an hour on spring tides. 

As almost all through routes between important centres at 
the present time contain links of narrow canal, the effect of these 
diversities of gauge is to confine any long-distance through traffic 
to narrow boats. Nothing but a narrow boat can navigate 



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858 IMPEOVEMENTS BEQUIBED IN IKLANB NAVIGATION. 

between London and Northampton, Leicester, Nottingham, or 
Manchester, and nothing but a narrow boat can get into or out 
of Birmingham. If an attempt be made to take a narrow boat 
from London to Leeds, it will fail altogether, as it will be stopped 
at either "Wigan, Sowerby Bridge, or Cooper Bridge by the locks 
of the Leeds and Liverpool canal, or Calder and Hebble naviga- 
tion, which, although of twice the width required by the narrow 
boat, are 10 feet too short Again, the narrow boat occasions a 
large amount of transhipment, as it is not safe to send it on wide 
estuaries or tidal waters. When goods are to be sent from 
London to Liverpool direct, narrow boats to load them cannot 
be sent lower down the Thames than Greenwich, and even then 
they will have to be fastened two together, side by side, for 
stability. When the boats arrive at either Runcorn or Ellesmere 
Port, the cargo will have to be transhipped into flats, as under 
no circumstances is it safe to send them down the Mersey estuary. 
Similarly, a narrow boat cannot be sent from London to Hull, as 
it is not fit to go below Stockwith on the river Trent, or on the 
river Humber. In the case of cargo in Leeds for delivery in 
London, the author will presume that it starts from Leeds in a 
short boat measuring 57 feet 6 inches in length and 14 feet beam. 
It can proceed by way of Castleford, Wakefield, Sowerby Bridge, 
Rochdale, Manchester, Runcorn and Ellesmere Port to Chester 
on the Shropshire Union canal, where it will be stopped by the 
insufiicient width of the locks ; and, for the same reason, if it 
travels by the river Weaver and the Trent and Mersey canal of 
the North Staffordshire Railway Company, it cannot proceed 
further south than Middlewich. Again, seeking to reach its 
destination by another route, it can journey by Wakefield, 
Bamsley, Doncaster, Keadby, Newark, Nottingham, Lough- 
borough and Leicester as far as the flight of seven locks at Wat- 
ford (Northamptonshire) on the Grand Junction canal, where it 
would be again stopped. These locks can only accommodate 
narrow boats, and form the sole remaining obstacle to prevent 
the boat from reaching London. 

Supposing that the author wished to take a cargo from 
Birmingham to King's Lynn, he would reach Peterborough with 
his narrow boat without difficulty, at any rate so far as the gauge 
of the navigations is concerned. At Peterborough, he would be 
unable to follow the direct route by entering the Middle level, 



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IMPEOVEMENTS BEQTHRED IN INLAND NAVIGATION. 



859 



as the entrance-lock, called Stanground sluice, is too short, and 
it would be necessary for him to travel vid Wisbech to the Ouse 
at Salter's Lode. This, as again the locks at Wisbech and 
Salter's Lode are too shorty he could only do by waiting at 
Wisbech for a spring tide to level the water in the river Nene with 
that of the Wisbech canal, and also at Salter's Lode for another 
spring tide to level the water in the river Ouse with that of Well 
creek. Tet another difficulty of a diflferent nature will present 
itself on this journey, for the horse whicb the author had brought 




Pig. 9.— Hincaoter Tunnel, on the Lancaster Canal of the London 
AND North-western Railway Company. 

from Birmingham to tow his boat will be useless in the Pen 
country, as he cannot jump. In the Bedford level and district, 
gates are not placed at the points where the towing-path passes 
through the various boundary-fences, but stiles (some of them as 
high as 2 feet 7 inches) are provided instead. All towing horses 
have to jump these stiles and frequently give themselves nasty 
knocks in so doing. 

Seeing that a barge of 60 tons only takes the same crew and 
practically only the same power to haul in a good waterway as 
a narrow boat, of the same leng^, but of half the width and 



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860 IMPROVEMENTS REQTJIKED IN INLAND NAVIGATION. 

capaxjity, and that the barge of 60 tons is suflSciently seaworthy for 
all ordinary estuary work, the author considers that this vessel 
would form the best minimum unit to which all alterations for 
the purpose of standardizing British waterways should be worked. 
This would also accord with the case of any branch narrow-boat 
canals at present existing, and not thought worthy of any capital- 
expenditure, as two narrow boats are the exact equivalent in a 
lock of a barge of 60 tons. For the most important main lines of 
canal, the author would suggest locks with a capacity of at least 
three barges of 60 tons, in which case the locks should be divided 
again by a third intermediate pair of gates, so that a lock for 
one, two, or three barges could be readily made. The average 
top width of a narrow-boat canal is 40 feet; but a very small 
proportion of this width is available for loaded boats, on account 
of the flat shelving slope to which the banks are usually formed. 
If these slopes were taken out and the canal deepened and walled 
on both sides, no extra width of land would be required to make 
a narrow-boat canal available for barges of 60 tons. 

Concerning mechanical haulage on canals, a certain amount 
has from time to time been written. By some persons, it would 
appear to be regarded as a panacea for all the ills of canals in 
their present condition, and not long ago a daily paper made the 
startling announcement of a ** report that mechanical haulage 
was about to be practically tested for canal traffic." Mechanical 
haulage by steam-boat has been known on canals for upwards of 
one hundred years, but it has never greatly developed on account 
of the smaller canals being so badly adapted for its use, just as 
the heaviest type of modern locomotive would be quite unsuitable 
for work on the original permanent way of one of the early 
railways. 

The advantages sought to be obtained by any system of 
mechanical haulage are obviously greater speed and greater 
loads than those taken by horses ; and, as a large proportion of the 
through routes in this country contain narrow-boat canals, it will 
be well to examine particularly the question of haulage aa 
applied to them. Contrary to what is often supposed, haulage 
by steam or other form of motor-boat on ordinary narrow canals, 
adds but little to the speed of vessels as compared with horse- 
haulage. Whatever horsepower may be developed, the rate of 



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IMPROVEMENTS REQUIRED IN INLAND NAVIGATION. 



361 



progress is limited by the ease with which the water in the canal 
can get past the vessel as it travels : this is governed by the pro- 
portion of the cross-section of the waterway to the immersed sec- 
tion of the vessel, subject to the proviso that with a given im- 
mersed section of vessel and a given section of waterway, the 
waterway which has the most water beneiath: the vessel, and the 
sides of which more closely approximate to the vertical, will give 
the best tesult. Any attempt to increase the speed beyond what 
the section of the waterway permits, merely causes a waste of 




Fig. 10.- 



-Pebshore Nayigation-wetr, on the Loweb Avon 
Navigation, Wabwickshibb. 



power, heaps up the water in front of the vessel, creates a breaking 
wave highly injurious to the banks of the canal, aaid renders the 
vessel more difficult to steer. And further, it is not practicable 
on the general run of narrow-boat canals to gain any advantage 
by making use of mechanical haulage to tow a train of boats. 
Long pounds of water are the exception and not the rule, and at 
every lock each boat has to be locked through separately, so that 
in the case of a train of five boats the delay at each lock will be 
at least five times as great as in the case of a single boat. Again, 
if the working of boats in trains were universal on narrow canals, 

27 



VOL. XZXin.-l906.lfO7. 



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862 IMPROVEMENTS EEQITIEED IN INI4AND NAVIGATION. 

delay and inconvenience would be constantly caused by tlie 
abstraction of sundry locks of water from the short pounds at 
one time, without any corresponding' replenishment from the 
pound above, thereby causing, temporarily, a serious reduction 
of the navigable depth. 

The author's company own 20 narrow steam-boata, and nearly 
all of them are engaged in the London and Birmingham traffic. 
They measure 71 feet in length by 7 feet beam, and draw 3 feet 
6 inches of water when loaded. Owing to the space occupied by 
the machinery, these boats only curry about 17 tons instead of 
from 28 to 30 tons, the load of an ordinary narrow boat, and 
consequently they always have to work towing one narrow boat 
behind them. On the Grand Junction canal, where the locks 
are large enough to accommodate the two boats at one time, this 
works well enough ; but, when passing over the Warwick and 
Kapton, and Warwick and Birmingham canals, where the locks 
are narrow, delay is occasioned by each boat having to be locked 
separately at every lock. The author is of opinion, therefore, 
that before mechanical haulage can come into general use on 
the waterways of England, the channels of the narrow canals 
must be improved so as to permit of greater speed, and the 
capacity of the locks must be enlarged so as to accommodate a 
suitable train of boats at one time. 

Passing from the steam-engine to consider the modem motors 
available for propelling canal-boats, the author may say that 
he has not yet seen any intemlal-combustion engine which he 
considers sufficiently reliable for the ordinary everyday work 
of through traffic. On the question of safety alone, he could 
not advise the use of any motor requiring petrol to work 
regularly through tunnels. The chance of a petrol-fire in a 
long tunnel, which might easily at the same time contain a tow 
of over 20 boats having upwards of 50 people on board, is not 
lightly to be risked. The danger of such liquids, giving off 
inflammable vapour at ordinary temperature, has been only too 
well demonstrated by the explosion on the Regent's canal of 
October 2nd, 1874, and, although the great amount of damage 
done was caused by gunpowder, it no doubt owed its origin to 
leaky benzoline or naphtha casks. The use of petroleum or paraffin 
oil for working motors m boats has the advantage over petrol in 
regard to risk of accident from inflammability ; but it is not per- 



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DISCUSSION — ^IMPEOVEMEXTS BEQUIRED IN INLAND NAVIGATION. 86^ 

missible on vessels carrying damageable cargo, on account of 
the all-pervading and most penetrating smell given off by it. 
The writer has lately inspected the wooden hull of a canal tug- 
boat from which a petroleum-engine had been removed after a 
few months' work in order to give place to a steam-engine, and • 
although the engine and the top and sides of the engine-room 
down to the gunwale had been removed for some days, the odour 
of petroleum arising from it was most pungent. Of all types of 
internal-combustion engine, the author considers the suction 
gas-engine open to the least number of objections for use for 
canal-boat propulsion ; but it has yet to prove its ability to keep 
time with steam on long journeys. 

The most desirable motor of all for the purpose would doubt- 
less be an electric motor driven by storage batteries, to be ex- 
changed for others freshly charged as required at different points 
on the canal, but such a system must of necessity await the 
invention of an accumulator of less weight and size, and costing 
less to maintain, than any that are on the market at the present 
time. 

The author may briefly recapitulate his views as follows: — He 
is of opinion that, when the waterways which it is considered 
desirable to improve have been selected, the first step should be 
to re-organize the authorities controlling them ; and that, when 
the works of improvement have been carried out and efficient 
waterways provided, the problem of mechanical haulage will soon 
solve itself. 



The President (Mr. Maurice Deacon) said that Mr. de Salis,. 
in his paper, had discussed an extremely interesting subject, very 
largely from a commercial point of view ; and, as it was particu- 
larly interesting to the colliery-owner, he thought that it should 
claim their attention and consideration. Railway companies were 
large owners of canals, and the owner of a small section might 
prohibit the utilization of the adjacent waterways to any useful 
effect. Mr. de Salis had pointed out that it was useless to hope 
for reasonably cheap water-carriage on through routes, until the 
whole of the "innumerable* canal companies, which occupied the 
waterways, could be either induced to amalgamate, or to sell 



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364 DISCUSSION — ^IMPROVEMENTS REQUIEED IN INLAND NAVIGATION. 

their undertakings to a single proprietor. Some years ago an 
attempt was made to amalgamate the several canals connecting 
the Midland coal-fields with London, but one or two of the canal 
companies did not approve of the proposed scheme of amalgama- 
-tion, which, from accurate calculations, would have enabled coal 
to be carried from the Midland coal-fields to London for 5s. per 
ton instead of the 68. 6d. then paid to the railway companies. 
The difficulty, with regard to passing through small locks, might 
be overcome by fitting the boat with wheels, and running it over 
a railway, of the required gauge, laid at the side of the lock. 

Mr. W. Peice Abell said that he was surprised that canals 
continued to exist under the vexatious obstructions to their 
intercommunication. If the authorities would undertake the 
nationalization of canals, greater good would ensue than from 
the proposed nationalization of railways. 

Mr. Fhank Raynee (River Trent Navigation) said that Mr. 
de Salis had had an unique experience of the waterways of 
England in regard to their works, natural features and trades. 
The River Trent Navigation, with which he (Mr. Rayner) was 
associated, were carriers, as well as owners of navigation rights, 
and unfortunately they knew the great difficulties which arose 
from the multiplicity of companies and authorities that had 
control over the inland waterways. There was absolutely no 
justification, so far as efficiency was concerned, for the continued 
existence of these innumerable bodies. In the case of the 
Bedford level and adjoining navigations, nine distinct authorities 
controlled a length of about 86 miles; and, in the case of two 
short navigations, there was no controlling authority. Conse- 
quently, there was no uniformity, and this led to endless con- 
fusion and difficulty. His own view was that the country 
should be divided into natural districts, following the great 
watersheds of the country, that each watershed should be en- 
trusted to a board of management, and that a central authority 
should be responsible for ensuring uniformity of gauge, condi- 
tions and maintenance, and that the works and control of the 
boards of management were consistent with each other. He 
agreed with Mr. de Salis in giving a word of commendation to 
some of the railway companies who did their duty to their 
canals; but they were in the minority, and there was endless 



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DISCUSSION — IMPROVEMENTS REQUIRED IN INLAND NAVIGATION. 865 

difficulty in conveying traffic over waterways controlled by railway 
companies. Independently-owned canals welcomed mechanical 
traction; he thought that, so long as a proper speed was not 
exceeded, it was desirable, and it kept down weeds : but railway 
companies alleged that it would burst the banks. In one railway- 
owned canal, the banks would withstand the pressure of pleasure 
steamboats, but when cargo was conveyed instead of passengers, 
the use of steamboats was said to be dangerous and was pro- 
hibited. Independently-owned canals did not raise artificial 
difficulties, but many railway companies, on the contrary, would 
not keep their canals open by such measures as breaking the ice 
in winter : they said that those who paid the tolls should provide 
horses ; and they placed other obstacles in the way of traffic. A 
flagrant case existed of a railway-controlled canal, which before 
the railway-days had perhaps hundreds of thousands of tons 
passing over it, but now the water-supply was said to be insuffi- 
cient for a small fraction of the traffic. There should be a 
minimum barge, to which all alterations for standardizing water- 
ways should be designed, but the question of a standard canal 
or a standard barge should not be rigidly enforced. Where 
natural conditions admitted, that minimum should be multiplied 
as much as possible, and if a barge carrying 60 tons was found 
to be a practical minimum, then, as in the case of the River Trent 
Navigation, where the water-supply and other natural features 
enabled them to do so, that minimum might be multiplied and 
trains of barges might be passed through the locks at once. It 
should be borne in mind that when a certain tonnage, with a tug 
or other propelling power, was exceeded, practically all the 
freight earned by the additional tonnage was profit. The cost 
of towing 60 or towing 70 tons was practically the same, assuming 
that the waterway was in a proper condition. He agreed that, 
with improved organization and waterways, and mechanical 
means of propulsion, a large traffic would follow. 

Mr. L. F. Vernon-Harcourt said that Mr. de Salis had 
shown plainly the difficulties which, at present, confronted convey- 
ance on through routes. The question of the length of canals and 
navigable waterways was not a very important matter, but it was 
curious that the figures contained in the first report of the Royal 
Commission on Canals did not agree with those approved by 



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866 DISCUSSION — IMPBOVEMENTS REQUIRED IN INLAND NAVIGATION. 

the Board of Trade. He looked forward with great interest to 
the final report of the Eoyal Commission on Canals, which might 
be issued before the close of the present year. The Royal Commis- 
sioners had inspected canals in Belgium, France and Germany ; 
but, on Continental waterways, the conditions were very different 
from what they were in this country. In Germany, barges, carry- 
ing up to 1,000 or 1,200 tons, could be used on the large navigable 
rivers; the standard barge, on French waterways, carried 300 
tons ; and, in Belgium, the standard barge carried 400 tons. Des- 
pite the improvements carried out on French waterways, the bulk 
of the traffic was conveyed on the waterways going into Belgium, 
from the northern coal-fields, and along the river Seine ; and, 
in the south of France, there was very little traffic, even over 
the waterway, originally made as a ship-canal, connecting the 
Mediterraneaax with the Bay of Biscay, and on most of the other 
central and southern waterways, notwithstanding the improve^ 
ment of these waterways, making all the main canals of a uni- 
form gauge for barges carrying 300 tons. Through-route water- 
ways should be placed under one control. Mr. Rayner had men- 
tioned the possibility of grouping them according to the 
drainage-areas; and, so far as rivers were concerned, that 
would be desirable, if Britain had such great rivers as they 
had on the Continent. It was desirable to group the rivers 
according to the basins ; but if they dealt with canals in that way, 
they would find that most of the canals from the centres of 
trade to the various ports passed through several river-basins, 
and a large number of locks would be required. Mr. J. A. 
Saner, in a paper read before the Institution of Civil Engineers 
early last year, proposed the creation of a number of through 
routes ; * but it was necessary to provide through routes of suffi- 
cient size, and to raise money for that purpose. Although it was 
desirable that the separate authorities should be abolished, it was 
not easy to induce them to give up whatever rights they might 
possess. He approved of the creation of certain through routes, 
and in a paper,t read before this Institution at Birmingham, a 
few years ago, he pointed out that a route from Birmingham to 

* "On Waterways in Great Britain," hj Mr. John Arthur Saner, Minutes 
cf Proceedings qf The InstittUion of Civil Engineers^ 1905, vol. clziii., page 21 and 
plates i., ii. and iii. 

+ "Inland Naviffation, with Special Reference to the Birmingham District," 
by Mr. L. F. Vemon-Harcourt, Trans. Inst, M. E., 1896, vol. viii., page 611. 



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DISCUSSION — IMPEOVEMENTS B£QT7I|LBD IN INLAND NAVIGATION. 867 

the sea by Worcester and the river Severn would probably prove 
useful and profitable. Routes, however, say, from Birmingham 
to the Mersey, to the Humber, or to London, would have to cross 
a number of water-partings, which made it extremely expensive 
to construct a satisfactory waterway. He agreed with Mr. de 
Salis that if through waterways were provided, haulage would 
not prove an insurmountable difficulty. The financial difficulties 
encountered during the construction of the Manchester ship-canal, 
a waterway for ocean-going vessels, had deterred people, more 
than one would wish, from undertaking schemes for the improve- 
ment of inland waterways. In the meantime they should wait 
for the decisive report of the Royal Commission on Canals, who 
might formulate a scheme, other than for the purchase of the 
canals by the State; because he did not think that would be a 
practical scheme, or one that a government should undertake. 

Mr. GoEDON Thomas (Grand Junction Canal) said that Mr. 
de Salis' paper might be taken as correctly representing the great 
difficulties met with by the trader who required to navigate upon 
a canal. Traders were now in the hands of the railway com- 
panies, and he asked whether the companies served mine-owners 
conveniently and at such rates as enabled them to compete, say, 
with Continental and other competitors. From his own know- 
ledge and from the evidence that had been given before the Royal 
Commission on Canals, it appeared to him that traders were not 
satisfied. Consequently, with the difficulties at present existing, 
he asked whether the canals could be so improved at a reasonable 
expenditure as to enable colliery owners to be placed in a better 
position. He had hoped that Mr. de Salis would have stated the 
speeds and relative costs of hauling by the several systems em- 
ployed by his firm, as compared with railways; and what the 
costs would be with an improved canal, such as he had suggested, 
taking barges of 60 tons.. Personally, he was rather in favour of 
a load of 80 tons, by reason that the present naiTOw boat could 
carry 40 tons, and it was merely putting the maximum load in 
pairs through one lock. A load of 80 tons seemed convenient, 
and it could be hauled through the improved canal at the same 
rate as a load of 60 tons ; and, therefore, a load of 80 tons in one 
vessel could be taken from the country (especially if taken in 
trains of three) in improved canals and improved lockage at 



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868 DISCUSSION — ^IMPROVEMENTS REQUIEED IN INIAND NAVIGATION, 

possibly one-half of the present rate, say, only 0'442d. per ton 
per mile. Taking* any district, say, Stafiordshire to London, the 
rate was 7s. per ton ; and on the improved canal, under improved 
conditions, the rate would be reduced to 3s. 3d : thai would be 
an enormous advantage to the country, and it would require no 
heroic system of ship-canals carrying vessels of 1,000 tons. The 
speed of the steamers and butty-boats worked by Messrs. Fellows, 
Morton and Clayton, Limited, was, on a level pond, 3i miles per 
hour ; but that speed was reduced (owing to various reasons) for 
through traffic, say from London to Birmingham, a distance of 
135 miles, to 2-15 miles per hour. On that route, the traffic 
passed through 157 locks, occupying 14 hours 64 minutes; and,, 
in addition, 9^ hours were lost through slowing down when 
approaching bridge-holes. Consequently, about 24^ hours were 
lost by blocks in the waterway, which might, with improved 
conditions, be entirely abolished. One of the greatest difficulties- 
in improving or maintaining canals was the water-supply. The 
present locks were of antiquated construction, and an improved 
system of lockage would have to be adopted. At the present 
time there was nothing more efficient than inclined planes or 
vertical lifts, which could be constructed at much less cost than 
a flight of Ipcks. In addition, they saved time, and their 
capacity for passing traffic was almost unlimited. The whole of 
the bridges, throughout the length of any main canal, would 
also require reconstruction. The proper sectional area of a 
canal should not be a wide canal with a big surface-area exposed 
to evaporation and leakage, but a section approaching a rect- 
angular form, with a depth at least one-half greater than the 
draught of the vessels frequenting it. These dimensions would 
allow a much greater speed than at present, and the cost of main- 
tenance of the paths, banks and dredging would be reduced. A 
canal, 45 feet wide and 7 feet deep, would take craft with a capacity 
of 80 tons ; and it could be constructed, to connect the four water- 
ways of England, at a moderate cost, requiring the purchase of 
very little land, and with little disturbance of important works 
on the banks of the canals. Improvements 'had not been carried 
out, owing to the past action of Parliament, particularly in 1846, 
in permitting railways to control certain links. The Gband 
Junction canal was hemmed in, owing to a policy which nobody 
could blame Parliament for having followed, for they all liked to- 



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DISCUSSION ^IMPKOVEMENTS REQUTBED IN INLAND NAVIGATION. 86^ 

experiment ; but, when they found how detrimental it was to the 
progress of the canals, it was not flattering to our commonsense 
that they should have allowed it to continue for so many years. 
The Grand Junction Canal Company tried in 1853 to bring about 
a large amalgamation, but they were stopped by railv/ ay- owned 
links. They now owned or had leased 171 out of 180 miles of the 
route from the Nottingham and Derbyshire districts to London; 
but the last few miles were in the hands of a railway company. The 
maximum craft only carried about 22 tons, and frequently that 
load was reduced to 10 and 12 tons, so that it was absolutely 
impossible for traffic to be brought profitably from such a dis- 
tance. Large sums of money had been spent in endeavouring to 
develop the traffic on that route, but they had failed owing to the 
fact that a few miles belonged to a railway company, which had 
been quite contented to leave the canal in the state in which it 
was handed over to them in 1846. As the independent and 
isolated canals could not possibly bring about any development,, 
this must be effected by a stronger body. He anticipated that the 
Royal Commission on Canals would express an opinion as to the 
type of canal that should be provided. In 1895, at the Birming- 
ham meeting of the Institution of Mining Engineers, some able 
papers were read, but the proceedings did not contain any recom- 
mendation as to. the views of the members on the subject, which 
was of such great importance to the coal trade. 

Mr. P. BoNTHRON (London) wrote, as one associated with 
lighterage matters, and who had traversed nearly every canal 
and canalized river south of the Midlands, that he had come to 
the conclusions that: (1) Large or ship-canals should be en- 
couraged. (2) Canals within a radius, say, of 20 miles of a port,, 
even as they are now existing could be made profitable; and 
dock or landing and railway-charges would be thereby avoided,, 
and a saving effected. (3) Unless the existing inland canals are 
developed, and the uncertainties of the water-difficulty overcome,, 
they cannot compete with railways. (4) In all the discussions 
of the canal-question, a very important point and factor had been 
quite overlooked, and that was the labour-question. Should any 
development take place, the wages of the canal-boatmen might 
have to be considered, and any advance of their present wages 
would seriously hamper the industry. Thames lightermen, he 



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-870 DISCUSSION — IMPROVEMEXTS BEQUIRED IN INLAND NAVIGATION. 

might mention, now received such wages that, with the exist- 
ing rates received for the lighterage of goods, this class of busi- 
ness was more or less unremunerative. (5) He agreed with Mr. 
Oordon Thomas (Grand Junction Canal) as to the size of barges 
to be used on certain canals, and as to the suggested widening of 
the locks so as to allow of the passage of craft carrying 80 tons : 
this could be done without great expense. Personally, he advo- 
cated the use of an even larger size of barge, if the depth of 
water so permitted. In conclusion, he considered that Mr. de 
Salis' paper was a very sound production ; it formed a good 
basis for future development, and it was written by a gentleman 
who had very wide experience relating to these matters. 

Mr. Owen J. Llewellyn (H.M. Inspector under the Canal 
Boats Acts) wrote that the main point in dealing with inland 
navigation was to remember that England was quite differently 
situated from all other countries. France, Belgium and Germany 
were all continually being urged as models to copy, and England 
was represented as being far behind them with regard to inter- 
communication. But the advocates of new and improved canals 
should remember that Hull, London, Bristol, Liverpool. Glasgow, 
and scores of other large towns were connected by the sea. And 
Manchester, Gloucester and other places, by reason of their ship- 
canals, could also be included. Therefore, with the exception of 
Birmingham, the Potteries and the Black Country of Stafford- 
shire, there was hardly a manufacturing district of importance 
which was not within 20 miles of a sea-connected port. 

The modern practice also of motor-traction, direct from works 
to dock-side, was a serious and growing competitor to canal- 
traffic ; and it was only an unpractical visionary who would pro- 
pose to use the taxpayers' money to support a system which had 
failed simply because of the competition of more modern and up- 
to-date methods of transit. T\^hen canals were in their hey-day, 
the alarmed road-authorities eased the gradients of some of their 
roads and laid down setts to compete with them. This had 
little effect, and canals continued to be extended. But as 
canals had beaten roads, so railways had beaten canals, and it 
was well known that canal companies were only too pleased to 
find anyone to take over their decaying businesses ; at the same 
time, the railway companies grasped at the idea of getting rid of 



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DISCUSSION — IMPROVEMENTS REQUIRED IN INLAND NAVIGATION. 87 1 

iheir only possible competitors. The story of the North Stafford- 
shire Railway Company, as told to him, makes this clear : When 
the directors of the Canal Company saw that railways were doing 
•so well elsewhere, they made a railway alongside of the canal, 
and guaranteed the canal shareholders against loss. The result 
had been satisfactory from a business point of view, although 
the absence of competition had prevented any cutting of rates 
and so naturally displeased certain traders. 

His (Mr. Llewellyn's) work took him all over England and 
Wales, wherever there was any navigable water, and he divided 
•canals into two distinct kinds: — (1) Where there would be 
water in any case ; and (2) where there would not be water, 
unless it was artificially introduced. He thought that if 
successful foreign canals were considered, it would-be found that 
very seldom were they anything but canalized rivers, or, at any 
rate, canals in flat districts. Of course, two rivers might be joined 
by a connecting artificial canal, although this was exceptional. 
English canals, as a rule, were entirely artificial and the number 
of' locks was very much greater than on the Continent. Extra 
locks not only entail extra cost, but they considerably shorten the 
lives of the boats. He was often amused by motorists who desired 
to turn canals into speed-ways, as if canals lay as straight from 
town to town as railways do. The reverse was the case and, out 
of flat land, the canal followed the contour of the country until 
the distance was often doubled. 

Ho agreed with Mr. de Salis in his opinion that rural or 
sparsely populated districts did not need intercommunication; 
and farmers had little to sell or buy now-a-days. 

It was impossible to augment speed on canals by engines, for 
it was well known that two donkeys could pull a laden boat as 
far as a team of big horses. Any increase in pace piled the 
water in front and dropped the stem of the boat on the bottom 
of the waterway. 

Because of late years there had been ho very long frost, it 
had been forgotten that such had ever occurred ; but a total stop- 
page of water-traction for nine weeks (as had frequently happened) 
would play havoc with an artificially-fostered big industiy. A 
week's delay even now produced a great deal of sufEering among 
the boat-people. 

The cost of enlarging tunnels (and there were numbers of 



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872 DISCUSSlON — IMPEOVEMENTS BEQUIfiED IN INLAND NAVIGATION. 

them) would be great, and if to this were added the cost of enlarg- 
ing locks and deepening channels in order to make all canals 
take a bigger size of boats, it would be difficult even for a company- 
promoter to issue a favourable prospectus. Further, until the 
last canal was finished in the new style, intercommunication 
would not be possible : there would be a record lock-up of capital. 

He felt rather like Balaam must have felt ; but, with his oppor- 
tunities of seeing canal-traffic, he would be blind if he could see 
(much as he should like to) any chance of success in the resurrec- 
tion of canals ; and very few people seemed to take any interest in 
the subject. 

He trusted it would be understood that, officially, he. had 
nothing to do with canals — only with canal-boats and their 
inmates. Neither was he an engineer or expert, but as he had 
said in his evidence before th» Royal Commission on Canals — 
he would be very dense if he did not keep his eyes open with 
regard to the surroundings of his work. 

In conclusion, he asked the question as to who was going to 
pay for the proposed enlargement of the canals ? And engineers 
seemed to be the only class who would make anything out of it. 

Mr. Arthur Carey (Widnes) wrote that Mr. de Salis' 
paper was a powerful and practical appeal, from a practical 
man who knew England's waterways as probably no other man 
knew them. There could be no doubt that manufacturers in 
this country suffered severely from the high cost of transport. 
If the cost of transport in this country were as low as it actu- 
ally was at the present time in Belgium and Germany, chemical 
products would be cheaper to produce by about 10 per cent, of their 
sale-price. This figure had been carefully calculated, and was 
the conclusion deduced from data collected by the Internal Trans- 
port Committee of the Society of Chemical Industry. The points 
to which Mr. de Salis had drawn the greatest attention were un- 
doubtedly the key to the situation : (l)The necessity for uniformity 
of gauge on the main through routes, and a material increase in 
that gauge. From his own experience, he would go further than 
Mr. de Salis and ask for waterways capable of taking barges carry- 
ing cargoes of 100 tons ; and, even then, the barges would be far 
short of the average barge, carrying 200 to 300 tons, used on Con- 
tinental canals. (2) Mr. de Salis drew attention to the multitude of 



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DISCUSSION — ^IMPUOVEMENTS B£QXJIB£D IN INLAND NAVIGATION. 378 

small authorities, controlling short lengths of water, thus adding 
greatly to the cost an.d inefficiency of management and to the 
•difficulties of traders. In addition, the number of canal com- 
panies made it very difficult, even in a journey of considerable 
length, to get the advantage of the comparatively low tolls 
charged after the first 30 miles. It was absurd in a journey of 
50 miles to be charged uniformly at the toll levied for the first 10 
miles because the barge travelled over water owned by five 
•different canal companies. There were, he thought, good grounds 
ior hoping that practical good would result from the labours 
of the present Royal Commission on Canals, and that they would 
help to remove one of the greatest handicaps from which British 
industries at present suffered : the high cost of inland carriage. 

Mr. W. WoBBY Beaumont (London) wrote that he agreed with 
Mr. de Salis' conclusion as to the use of steam-engines and in- 
ternal-combustion engines for canal-boats, more particularly relat- 
ing to the canals of Great Britain. He also agreed with his 
conclusion, at present at all events, that the steam-engine was in 
most cases the more suitable flexible motor, and that there was no 
doubt as to the force of objections of the kind he raised with 
regard to the use of petrol or petroleum in canal-boats. It was 
•quite possible, however, that ere long suction gas-producers and 
^as-eQgines might be employed for propelling canal-boats. 

Mr. J. A. Sanee (Northwich, Cheshire) wrote that he had 
long been of opinion that draatic improvements, both as to 
management and capacity of many of the English canals, 
required undertaking. His views had been fully set forth in 
the paper written for The Institution of Mining Engineers in 
1895 ; * also more recently in a paper read before The Institu- 
tion of Civil Engineers in November, 1905,t for which the 
Telford gold medal was awarded; and also in his evidence 
before the Royal Commission on Canals and Waterways in 
May, 1906.J In these papers, he had uniformly advocated that 
main trunk-canals should be constructed for conveying cargoes of 

• "Canals,** by Mr. J. A. Saner, Tratu, Inst. M. E., 1895, vol. viii., 
page 467. 

t "On Waterways in Great Britain," by Mr. John Arthur Saner, Minutes 
of Proceedings of The Institution of Civil Engineers^ 1905, vol. clxiii., page 21 and 
plates L, ii. and iii. 

X Report of Royal Commission on Canals and Waterways f 1906, vol. i., 
part ii., pages 35 to 51 ; and Appendix, third day, May 9th, 1906, pages 15 to 25. 



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874 DISCUSSION — IMPEOVEMEXTS BEQUIRED IN INLAND NAVIGATION^ 

not less than from 250 to 300 tons at a time. He knew that in the- 
opinion of some others, as well as Mr. de Salis, a boat of 60 tons 
was considered to be sufficient; but there was really not veiy 
much difference between what they advocated and what he had 
been advocating, inasmuch as everyone was agreed that a train 
of boats should be able to carry far in excess of this amount,, 
and that, therefore, the locks must be large enough to take^ 
several boat«, in which case they would also be large enough, 
should occasion require and circumstances develop (and he felt 
certain that they would) to allow of the use of larger craft-. He 
had not, of course, advocated the improvement of all canals, in the 
first instance, but had taken cross-country routes, such as Liver- 
pool, Birmingham and London ; Hull, Birmingham and Bristol ; 
and Manchester and Hull, as being the important routes. If these- 
were made with locks suitable for taking either a train of boats, 
each carrying 50 to GO tons, or vessels capable of carrying from 
250 to 300 tons at one locking, it would then be possible gradually 
to improve the smaller canals in such a manner that the smallest 
canal would eventually be able to take a boat of 60 tons. He quite 
agreed that a boat of 50 to 60 tons was the smallest which could 
safely navigate the estuaries of the Mersey and Humber, as he had 
had experience of such boats navigating both these estuaries. If 
canals were made so that these boats could penetrate to nearly all 
parts of the country, it would in his opinion effect a very great 
saving to the community in the cost of carriage ; but he did 
consider that main canals should be large enough to accommo- 
date craft of 250 to 300 tons, as he was quite convinced that 
within a short time after such canals were made, trade would 
so arrange itself as to enable them to carry full cargoes. 

Some years ago, he made a tour of inspection through some 
of the foreign canals, especially those in Belgium and Germany, 
and although the circumstances of trade in this country were 
somewhat different from those obtaining there, it was quite 
certain that the main through routes as suggested above would, 
within a few years, fully compensate the promoters and con- 
structors, whether such promotion and construction was carried 
out under Government guarantee or by private enterprise. 

He would like to remind the members that, despite all diffi- 
culties and apparent losses entailed through the construction of 
the Manchester ship-cadal, that canal had already improved the^ 



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DISCrSSION — ^IMPaOVEMENTS REQUIRED IN INLAND NAVIGATION. 875- 

trade of Manchester to a marvellous extent, and was now well 
on the way to remnnerating those who had supported it by lending 
mone5\ 

Mr. F. S. GiBDLESTONE (Bristol Docks) wrote that there had 
recently been signs of considerable activity in connection with 
the canal-traffic between Bristol and the Midland counties; and 
the Sharpness Xew Docks and Gloucester and Birmingham 
Navigation Company, who owned the canal, and the Severn and 
Canal Carrying Company, who carried the traffic, were actively 
interesting themselves in the question of shipments from the 
Midland counties at Avonmouth dock. This had been brought 
about to a very large extent by the increased opportunities for 
shipping at Avonmouth and the progressive policy of the Bristol 
Docks Committee in assisting in the effort to make the facilities, 
of Bristol better known in the Midland counties. In Birming- 
ham, a commodious warehouse was being constructed to replace 
the small building which had hitherto existed, and electric 
cranes and other modem appliances were being erected on the 
wharf to expedite the loading and unloading of merchandise. 
Recently the Gloucestershire and Birmingham Navigation Com- 
pany had been able to get the whole of the towing into their 
own hands, and improvements had been effected in this direction 
so that whereas formerly steam-tugs were only used to tow 
canal-boats through the tunnels between "Worcester and Birm- 
ingham, they were now used throughout the whole journey (with 
the exception of a short distance between Tardebigg and Wor- 
cester, where there was a considerable flight of locks and steam- 
towing would be of no advantage). The Severn and Canal Carry- 
ing Company had been induced to quote rates sufficiently low to 
secure various classes of traffic for Bristol which had not hitherto 
been shipped at that port, and a very substantial margin could 
be shown between canal and railway rates from the Midland 
counties to Bristol, and an even greater saving as against the 
rates to Liverpool. There was also a margin in favour of Bristol, 
between Birmingham-Bristol and Birmingham-Liverpool canal 
rates respectively. The time occupied in the journey was, how- 
ever, still an obstacle in the way of getting this route generally 
used, as it was not safe to calculate on less than five days for 
goods from Birmingham, and it required a longer period for 
goods from Wolverhampton and other districts. 



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576 DISCUSSION — IMPROVEMENTS REQUIEED IN INLAND NAVIGATION. 

Then again, at the present time, all goods received from 
north of Worcester must be transhipped between that place 
and Sharpness, as the canals around Birmingham were only 
-constructed to take ordinary canal-boats, say, up to 35 tons, 
whereas larger craft were necessary to navigate safely the 
waterway between Sharpness and Bristol. At present, he believed 
that, except on rare occasions, the transhipment was effected 
by manual labour, and no doubt time would be saved by 
the use of mechanical appliances. Various suggestions had 
l)een put forward to obviate the necessity of transhipping, the 
three principal proposals being: — (1) The construction of a 
oanal between Bristol and Sharpness; (2) the improvement of 
the canal between Worcester and Birmingham ; and (3) the con- 
struction of pontopns for conveying the canal-boats with their 
cargoes between Bristol and Sharpness. If the first proposal 
were carried out, a canal would have to be constructed for a 
distance of 16 to 18 miles. The canals around Birmingham cost 
about £15,000 per mile, and these, as beforementioned, would 
only allow the passage of a canal-boat carrying cargo up to 35 tons. 
Taking into consideration the increased cost of labour and mate- 
rails, and the fact that, if the canal as proposed was constructed, it 
would be necessary to make it available for craft up to 100 tons 
at least, it would probably cost not less than £30,000 per mile, 
which would mean a total cost of £540,000. There would also be 
the delays that a craft would experience in passing through the 
locks of the proposed canal from Avonmouth to Sharpness. 
At present, a boat can, in good weather and studying tidal 
conditions, accomplish the sea-journey between Avonmouth and 
♦Sharpness in, say, 3 hours, but this would probably be considerably 
increased by passage through the canal; but, as against this, 
there would be the freedom from tidal and weather delays. 
The cost of interest on capital, maintenance and working would 
be a considerable item ; while there would still be the difficulty 
of the canal to the north of Worcester, and unless only small 
boats were used transhipment would still have to take place. 

The cost of improving the canal between Worcester and 
Birmingham to take craft of 100 tons would be upwards of 
£200,000. This would still leave the canals in the district of 
Birmingham untouched ; and it must be borne in mind that only 
a proportion of the traffic of the district arises in Birmingham ; 



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DISCUSSION — IMPROVEMENTS BOEQUIRED IN INLAND NAVIGATION. 377 

wherefore transhipment would still have to take place, although it 
might be done at the canal-wharf in Birmingham instead of lower 
down the canal. 

The third proposal was by far the best and most economical 
scheme as yet put forward. The cost of providing pontoons, 
as compared with the other proposals, would be comparatively 
trifling and would not exceed £2,000 per pontoon ; and, even sup- 
posing that the cost was doubled, six pontoons could be provided 
for £24,000. The proposal was that canal-boats should bring their 
cargoes down to Sharpness, where the floating pontoon would be 
waiting in water-ballast ready to receive them. The compart- 
ments would be opened and the canal-boats propelled into the 
pontoon, after which the compartments would be closed, the 
water-ballast pumped out of the pontoon, and she would proceed 
either under her own steam or in tow to Avonmouth ; and, when 
inside the docks, the canal-boats would be brought out and 
their cargo loaded into the outgoing steamer. The same opera- 
tion would be put in {orce at Avonmouth, in the event of the cargo 
being for the Midlands. 

Mr. TJequhaet A. Forbes (London) wrote that he fully 
concurred with Mr. de Salis in the conclusions arrived at in his 
very interesting paper, that the first steps towards the improve- 
ment of our inland-navigation system must be the selection of 
such portions of the main system of waterways having inland 
communication with each other as would best repay expenditure 
upon their development, and the reorganization of the authorities 
controlling them. It also seemed clear from his description of 
the conditions of the system, that it was equally essential for the 
establishment of remunerative through traffic that a minimum 
scale of dimensions for all the waterways forming each through 
route, and a maximum rate for freight-charges for goods carried 
on them, should be definitely determined by some competent 
authority. 

One of the methods which might be suggested for effecting 
these reforms was the appointment, either by the Board of Trade 
or the Government, of a committee of experts, representing the 
principal canal companies, conservancy authorities, and railway 
companies owning canals, empowered to make the necessary 
surveys, investigations and arrangements for carrying them out. 

28 

VOL. XXX in -1908-1907. *^ 



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878 DISCUSSION — IMPEOVEMENTS REQUIKED IN INLAND NAVIGATION. 

The reorganization of authorities might then be accomplished 
by the establishment of single governing bodies for each of the 
great through routes, comprizing representatives of the various 
canal and navigation authorities now controlling the different 
waterways of vhich each was composed. Such bodies would be 
analogous in constitution to the Thames Conservancy Board and 
the Metropolitan Water Board, being representative of all the 
bodies entrusted with the regulation of the through route ; and 
their creation would promote the process of amalgamation and the 
establishment of the clearing-house system, which had been the 
chief factors in the success of the railway companies. At present, 
whilst each through railway route was governed by a single 
company formed by such amalgamations — ^the London and 
North-western Eailway Company, for instance, was a combina- 
tion of forty or fifty small companies — there was not a single 
through water-route which was controlled by less than ten 
different authorities; there were twenty-six competing bodies 
on the three connecting London and Liverpool, and twenty-seven 
on the four between London and Bristol. Such combinations of 
waterway authorities might be authorized to purchase links in 
through routes owned by railway companies, which, it might 
be noted, were now prohibited from acquiring any canal-interests 
without express statutory provision; but, as such links were 
apparently often retained by such companies at a loss, it would 
obviously be to their interest to co-operate in a scheme which 
would relieve them of some of their surplus traffic. The advan- 
tages of a clearing-house system had been so often demonstrated 
since its establishment was rendered possible, 19 years ago, 
by Section 44 of the Eailway and Canal Traffic Act, 1888 — 
notably in a report of 1892 by Mr. Waghom, counsel to the 
Cheshire Conference on Railway and Canal Rates — that it was 
needless to enter into them. It might, however, be pointed out 
that there were various provisions in the abovenamed Act, the 
systematic utilization of which by a strong combination of navi- 
gation authorities might materially tend towards the improve- 
ment of waterways and their freedom from railway-control. 
These were: the power conferred on the Railway and Canal 
Commissioners of making orders for the alteration of rates levied 
on railway-owned canals, where they could be proved to be 
calculated to divert traffic to the railway to the detriment of the 



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DISCUSSION — ^IMPEOVEMENTS REQUIRED IN INLAND NAVIGATION. 879 

canal or persons sending traffic over it or other adjacent canals 
(section 38) ; the extension of the provisions of the Railway and 
Canal Traffic Act, 1854, and the Eegnlation of Railways Act, 
1873, requiring* railway companies to afford all reasonable 
facilities for forwarding traffic from railways to canals (section 
37) ; the authorization of canal companies to enter into contracts 
and arrangements for through tolls (section 43) ; and the provision 
for the inspection by the Board of Trade of all canals dangerous 
to the public, or liable to cause obstruction to traffic, and the 
provision for their abandonment, if necessary, or, should the 
Board of Trade think fit, their transfer to any body of persons 
or local authority (sections 41 and 45). The last-named pro- 
vision seemed especially noteworthy, with regard to the acquisi- 
tion of all the links on any through route by a single governing 
authority. 

Although Mr. de Salis expressed himself in favour of State 
control of the main routes of waterway, he did not say whether 
he also advocated their ownership by the State. As regarded the 
first point, the State already possessed a limited control of this 
kind, administered through the Board of Trade, which might be 
extended by statute for the purposes above suggested if neces- 
sary. In order that it should be thoroughly effective, such an 
extended control* ought to be vested in a Special Water Depart- 
ment of the Board, entrusted not only with the regulation of 
navigation, but also with the conservancy of the water-system 
of the United Kingdom, on which not only navigation, but 
fisheries and water-supply for industrial and domestic purposes, 
were also dependent. The formation of such a department had 
been suggested by both the Salmon Fisheries Commission of 
1902, and the Sewage Disposal Commission in their Report of 
1903-1904, who also urged the appointment of subordinate boards 
for each watershed area, constituted on the lines of the river- 
boards or joint committees of county councils, which were now 
charged with the prevention of pollution in the rivers of the West 
Riding of Yorkshire, and the Mersey, Irwell and Ribble. 

With respect to the State purchase of canals, it must be 
borne in mind that the Caledonian and Crinan canals in Scotland, 
and the Maigue, Boyne, Tyrone and Shannon navigations in 
Ireland were the property of the State, and that they could not 
be regarded as being better managed or more remunerative than 



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880 DISCUSSION — IMPROVEMENTS REQTTIEED IN INLAND NAVIGATION. 

waterways belongiDg to canal companies or ordinary navigstion 
authorities. Although theoretically attractive, State purchase 
of the inland navigations was also open to the weighty objec- 
tions of the difficulty of obtaining the money necessary for the 
purpose ; the opposition that it would naturally arouse amongst 
the most successful canal companies, such as the Aire and Calder, 
Weaver, and Leeds and Liverpool; and the length of time 
requisite for carrying out effectively any scheme requiring the 
consent of Parliament. Its feasibility might, however, be 
experimentally tested by the acquisition by the State of any one 
of the main through waterways, or by its construction of one of 
the new canals projected during recent years — such as that for 
a canal capable of accommodating steam-barges connecting the 
Thames and Mersey ; that for the improvement of the Wilts and 
Berks canal; that for connecting Birmingham with the Trent 
and the North Sea ; or the ship-canal for connecting the English 
and Bristol Channels favourably reported on by Mr. Thomas 
Telford and Capt. Nicholls, R.N., in 1825. In conection with such 
projects, it appeared worth noting that nearly all the main water- 
routes ran from north to south, and that the construction of one 
uniting the Wash with the Bristol Channel might restore to the 
East-coast ports some of the large trade that they enjoyed, until 
the construction of Denver sluice at the close of the seventeenth 
century caused the silting-up of the Wash rivers. 

Mr. W. H. Hunter (Manchester) wrote that no one could 
deny that, for the greater part, the inland-navigation system 
of Great Britain was no better than an anachronism, which 
might have been tolerable (though even this was doubtful) 50 
or 60 years ago, but which was intolerable now. The striking 
instances given by Mr. de Salis of the hopeless manner in which 
the routes between London and Leeds were blocked, were suffi- 
cient to prove this point to demonstration. The difficulty was 
not so much to find a remedy for the admitted evil as to 
impel the traders and othera interested in the matter to seek 
the means for giving effect to remedial proposals. Whatever 
the Eoyal Commission on Canals and Waterways, which was 
now sitting, might, in their wisdom, recommend, it seemed 
futile to expect that, in the present state of public opinion in this 
country, funds for canal-improvement and development could be 



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DISCUSSION — ^IMPEO VEMENTS REQUIRED IN INLAND NAVIGATION. 88 1 

obtained, either from the Govemmeat, or from local authoritiee. 
It WBS a self-evident proposition that an improved system of 
inland navigation would be of great benefit to the commercial 
interests of Great Britain, but it must be admitted that a great 
part of the benefit would be due to the manner in which facilities 
for the water-carriage of goods would bring about a reduction 
in the rates for rail-borne traffic, to the detriment of the share- 
holders in British railways. Under these circumstances, it 
could not be supposed that the great railway interest would 
remain supine when eflPorts were being made to introduce effec- 
tive competition with railways by means of canals constructed 
or improved out of public money ; or that the mass of the people 
of this country, who had no direct interest in inland navigation, 
would be willing to submit to an increase in the burden of rates 
and taxes, already so onerous, for the sake of inducing this com- 
petition, either from the point of view of pure patriotism, or 
with the hope of obtaining certain commodities at a slightly 
cheaper rate. On the other hand, no man of affairs would at 
this present time delude himself with the hope that the private 
investor who looked only for a direct and immediate return for 
his money, could be persuaded to provide the capital necessary 
for so great an undertaking as that which would be required if 
our inland-canal system were to be brought up to date. A 
direct return of a satisfactory character could only be looked 
for in special cases where special trades were concerned — because, 
except in respect of the transport of minerals and heavy raw 
materials, the trade of this country was so largely of a retail 
character, that was to say, was distributed in such small parcels, 
that a smaller unit of conveyance than any canal-boat could 
supply was required for the conveyance of traffic. There were 
one or two points of detail, which might be regarded as fitting 
subjects of criticism in Mr. de Salis' paper, but they were not of 
great importance. As an instance, he described upland rivers 
made navigable by the provision of locks and weirs as having, 
usually, a stream flowing downwards with a velocity up to 3 or 4 
miles an hour. If he had divided these figures by 3, he 
would have been much more nearly correct: the figures which 
he suggested represent flood-velocities. Again, in dealing with 
the question of motors now available for the propulsion of canal- 
boats, Mr. de Salis referred in a somewhat deprecatory manner 



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382 DISCUSSION — IMPEOVEMENTS BEQtTIKED IN INLAND NAVIGATION. 

to internal -combustion engines; but he made no reference to a 
class of motor from which it seemed at the present time more 
was to be hoped for than from any of those named by him, 
that wa« to say, oil-engines of the Diesel type, which used 
crude petroleum-oil as fuel, in which no explosion took place, and 
in which the oil was ignited by compression, without any of the 
magneto-electric or other sparking arrangements which caused 
trouble and difficulty in so many gas-engines. 

Mr. G. W. Keeling (Cheltenham) wrote that his experience, 
and probably that of other engineers engaged on schemes for 
the improvement of waterways on which the income was in- 
sufficient to pay both the expenses and the interest on obligations, 
had been, that a large amount of sympathy, enthusiasm and 
moral support could be obtained in favour of schemes for the 
improvement of canals from traders, manufacturers, and public 
bodies. But the lack of financial support was probably due to 
the fact that business men, whilst appreciating the effect of navig- 
able waterways on the carriage of heavy goods in convenience 
and rates, had no faith in such waterways being ren^unerative. 
This feeling had possibly given rise to the proposal that the 
waterwaj^s should be improved and maintained by the State or by 
the county councils. He (Mr. Keeling) did not advocate the 
general enlargement of canals and making them of uniform 
gauge. 

In many cases, the sources of traffic and the supply of water 
would not justify the vei-y costly works involved and the expense 
of securing a larger supply of water. Canal-boats had a very 
useful size (carrying 36 t<)ns) and two of tliem abreast would 
pass through a barge-canal lock. He (Mr. Keeling) suggested 
that the convenient and economical course would be to leave the 
waterways in the hands of the present proprietors, but to en- 
courage the formation of trusts for districts; and that the 
State or the county councils should have power to advance 
capital, where necessary, for improvements desirable in the 
public interest, or to guarantee the deficiency in interest on 
such capital — subject to the condition that the tolls charged, 
and the maintenance and management of the waterway, should 
be to the reasonable satisfaction of the officers representing the 
State or the county councils. With regard to railway-owned 



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DISCUSSION — IMPROVEMENTS EEQUlRED IN INljiND NAVIGATION. 388 

canals, in many cases the railway companies were compelled 
to take them over, either by Act of Parliament or to satisfy the 
opponents of the railway bill, and in any case the transfer was 
sanctioned by Parliament. If it were now proposed to take such 
navigations out of the hands of the railway companies, with the 
object of their becoming active competitors for traffic, it appeared 
fair and reasonable that the capital expended by the railway com- 
panies in acquiring such canals or navigations should be 
returned to them ; and, in cases where the railway companies had 
been required to guarantee interest on canal stocks, that they 
should be relieved from such guarantees. Of railway-owned 
canals, the Kennet-Avon canal-navigations and the Birmingham 
canal-navigation were also well maintained. The towing path 
on the river Severn, between Gloucester and Worcester, was not 
now of importance, as the Sharpness Dock Company undertook 
the towing, between Gloucester, Worcester and Stourport, with 
their steam-tugs, at moderate charges. The current, running at 
12 knots per hour, referred to by Mr. de Salis, in the river Severn 
estuary, only occurred on the rising tide in high spring tides, at 
exceptional places, where the river was narrowed by promontories, 
such as at Beachley and at Old Sharpness point. 

Mr. John Nevin (Mirfield) wrote that one difficulty often 
overlooked in inland navigation was the supply of water, espe- 
cially in hilly country. Between Yorkshire and Lancashire, 
three canals crossed the Pennine chain. (1) The furthest south, 
the property of the London and North-Westem Railway Com- 
pany, was a narrow canal, from Huddersfield to Saddleworth: 
the locks being little more than 7 feet wide, would only take 
boats carrying a little over 20 tons ; and very little traffic passed 
through it. This canal passed through Pule hill by a tunnel 3| 
miles long, and this canal-tunnel was stopped for more than a 
year, while the railway company were driving a new railway- 
tunnel. (2) The Rochdale canal passed through the hills be- 
tween Todmorden and Littleborough, by locks, without a tun- 
nel. By this route from Hull to Manchester, the boats passed 
through three navigations, in addition to the river Humber, be- 
tween Hull and Goole: (a) the Aire and Calder navigation, 
from Goole to Wakefield ; (6) the Calder and Hebble navigation 
from Wakefield to Sowerby Bridge; and (c) the Rochdale canal. 



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884 DISCUSSION — IMPROVEMENTS EEQtJIBED IN INLAND NAVIGATION. 

from Sowerby Bridge to Manchester. The Aire and Calder 
navigation could take boats carrying over 100 tons; on the 
Calder and Hebble navigation, the smallest lock was 56 feet 
long and 14 feet wide, with a draught of water of 5 feet, and the 
boats could carry 60 tons. On the Rochdale canal, the locks 
were 68 feet long and 14 feet wide, with a draught of water of only 
4 feet, and boats could carry 45 tons only. The Aire and Calder 
canal, fed from the rivers Aire and Calder, had a plentiful 
supply of water. The Calder and Hebble canal was fed from 
the river Calder, and the high level on the Halifax branch was 
supplied by pumping. The Eochdale canal had a limited 
supply from streams and reservoirs in the hills. (3) The third 
waterway from east to west, the Leeds and Liverpool canal, reach- 
ing from Leeds to Liverpool, crossed the Pennine chain between 
Colne and Skipton. It was supplied from streams and reser- 
voirs, and the navigation was often stopped in summer for want 
of water. No further supply could be procured for these three 
canals, as the whole of the watershed was now taken up for 
domestic water-supply in Lancashire and the West Riding of 
Yorkshire. If the locks on the Calder and Hebble navigation 
were lengthened to the same dimensions as those on the Roch- 
dale canal, and if the depth of the water in the Rochdale canal 
were increased at least by 1 foot, this through navigation would 
be much improved. It must be remembered, however, that if 
the dimensions or the depths of the locks were increased, more 
water would be used by each boat passing through them, and this 
would intensify the want of water now ex.perienoed in a, dry 
summer. The expense of pumping was so great that it would be 
commercially impossible. The Rochdale canal and the Leeds and 
Liverpool canal at present only paid a dividend of 1 per cent, to 
their proprietors, and he could not suggest how any Act of Parlia- 
ment was likely to reduce the expenses. 

The President (Mr. Maurice Deacon) proposed a vote of 
thanks to Mr. de Salis for his paper. 

Mr. G. E. Coke seconded the resolution, which was cordially 
approved. 

Mr. DE Salis, in acknowledging the vote of thanks, said 
that there was only one point upon which he would like to 



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DISCUSSION — IMPEOVEMENTS EEQtTlRED IN INLAND NAVIGATION. 385 

reply, and that was the means of getting over a flight of locks 
by transport on wheels. The great difficulty was that the boats, 
if of any considerable size, must be taken out of the water and 
floated in a tank. The only craft that had been worked dry, 
uphill on wheels, had been small tub-boats of 4 or 5 tons, such 
as were formerly used on the Bude canal in Cornwall, and on the 
Coalport canal in Shropshire. A boat of any size, with a full 
load, could not be supported at two points. An accident 
occurred on the Grand Junction canal to a boat loaded with 
chalk, that came to a lock to go downhill. The man in charge 
drew the paddles to let out the water, and feeling thirsty ad- 
journed to the adjoining public-house, leaving the boat to 
settle down of its own accord. A pufi of wind blew the boat 
back and the stem settled on the edge of the sill, and before the 
water had fallen down more than 2 or 3 feet, the boat was broken 
in two. 



The meeting then adjourned, and, on its resumption, Mr. James 
Cope Cadman took the chair. 



Mr. W. B. M. Jackson's paper on " A Bye-product Coking- 
plant at Clay Cross '' was read as follows : — 



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386 A BYE-PRODUCT COKING-PLAXT AT CLAY CROSS. 



A BYE-PRODUCT COKING-PLANT AT CLAY CROSS. 



By W. B. M. JACKSON. 



Introduction, — In writings the following few notes on the 
working of a bye-product coking-plant with which the writer is 
connected, he does not claim to be able to find anything new to 
lay before the members, but hopes that the facts given will be 
of some interest, more especially to those members who are con- 
nected in any way with the manufacture of coke. 

Coke has been manufactured at Clay Cross for many years, 
the date of the original ovens being 1840. These ovens, 9 feet 
long and 6 feet wide, of the bee-hive type, were erected under 
the supervision of the late Mr. George Stephenson, who at that 
time was one of the owners of the Clay Cross collieries, he having 
discovered the value of the coals existing in the neighbourhood, 
whilst making the tunnel at Clay Cross for the then North Mid- 
land railway. It is interesting to note that these ovens were 
erected for the purpose of producing coke to be consumed by 
locomotive engines ; and, further, they were built with old stone 
sleepers that were taken up from the North Midland railway. 
These ovens numbered 52 in two double rows, and an old esti- 
mate shows that the cost of labour per oven was £3 7s. 4(i. Large 
coal was used exclusively for coke-making, taken from the Low 
Main or Tupton seam. The coal made a large coke which was 
used in the blast-furnaces. From time to time, the coke-ovens 
have been altered, improved and added to, and another range of 
bee-hive ovens, 50 in number, was built in 1870. These ovens, 
10 feet 4 inches in diameter and 8 feet high to the apex, were 
built with flues, and the waste-gases were used for generating 
steam at two egg-ended boilers at a colliery close by. In 1889, 
37 ovens of the original battery were rebuilt: these ovens were 
10 feet inches in diameter and 8 feet 2 inches high to the eye; 
and the waste-gases generated steam from three egg-ended 
boilers. Washed and crushed coal from the Black-shale and 
Tupton seams was used in these ovens. 



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A BYE-PRODUCT COKING-PLANT AT CLAY CEOSS. 887 

ExperimerUal Coke-ovens. — Some years later, it became ap- 
parent to tke writer that retort-ovens and a bye-product plant for 
dealing with the waste-gases must lead to more satisfactory 
results. Considerable doubt existed as to whether the slack from 
the Clay Cross collieries would be suitable for the manufacture 
of coke in retort-ovens; and, after many installations both in 
this country and on the Continent had been inspected, it was 
decided that it would be advisable to erect a small number of 
trial-ovens. Eight ovens were therefore built in 1904 by the 
Simplex Coke-oven and Engineering Company, Limited, the 
agents for the Entreprises de Constructions de Fours a Coke 
et d'TJsines M^tallurgiques. These ovens, 33 feet long and 
6 feet 9 inches high, were arranged in pairs, each pair being of 
a different width, the first being 24 inches; the second, 26 
inches ; the third, 28 inches ; and the fourth, 30 inches ; with a 
view to ascertaining the most suitable dimensions. It was proved 
that the narrowest ovens gave the most satisfactory results, and, 
ultimately, when the main battery was built, the width of the 
oven was again reduced, as will be shown later. The side-flues 
of the ovens were horizontal, and were three in number. The 
eight ovens were divided into two sets of four, varying in the 
manner in which the gas passed in the flues; one set was 
arranged so that the gas entered at one end and passed the full 
length of the ovens and thence to the waste-gas flue. In the 
other set, a dividing wall was built midway in the flue, and the 
gas was admitted at both ends and coursed backwards and for- 
wards between the end and the dividing wall, as shown in fig. 1 
(plate xii.), and so underneath the oven itself into the waste-gas 
flue. It was found from experiments that the latter form of flue 
gave the best results : the heat being more regular and easier to 
control. 

At first, the slack, after being washed and crushed, was 
put into the ovens from the top; but the results were not 
entirely satisfactory, the coke coming out small and not of a 
very good appearance. Experiments, therefore, of a somewhat 
rough character (owing to the absence of anything in the nature 
of machinery), were made to prove, as far as possible, what would 
be the result of compressing the slack. This was done by filling 
wooden boxes with slack, and compresvsing by hand : the bottom 
of the box was then drawn into the ovens, with the compressed 



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888 A BYE-PRODUCT COKING-PLANT AT CLAY CEOSS. 

cake, and during the process of carbonization the wood was 
burnt and the slack was left as a cake of coke. The advantage 
of compressing was immediately observable and the small quan- 
tity of coke, made from slack compressed in boxes, was larger 
and better in every way than the remainder of the charge. 

Simplex Retort-ovens. — After this plant had been at work long 
enough to prove that a really good coke could be made from the 
slack in bye-product ovens, by means of using a compressor, a 
contract was entered into with the Simplex Coke-oven and 
Engineering Company, Limited, for the erection of 34 ovens and 
a complete bye-product plant: it being arranged, should it be 
deemed advisable to extend the plant by an additional 16 ovens, 
that the bye-product plant should be capable of dealing with this 
extension. These ovens were completed and set to work in Novem- 
ber, 1905, and consisted of 34 bye-product recovery-ovens and a 
bye-product plant, with three Lancashire boilers, 30 feet long and 
8 feet in diameter, heated by the waste-gases, and working at a 
pressure of 100 pounds per square inch. The plant was enlarged 
in January, 1907, by the addition of 16 ovens and two Lancashire 
boilers, 30 feet long and 8 feet in diameter. 

The complete plant consists of 50 Simplex bye-product 
recovery-ovens, with a bye-product plant for the recovery of 
sulphate of ammonia and tar; five Lancashire boilers, 30 feet 
long and 8 feet in diameter, heated by the waste-gases, and 
working at a pressure of 100 pounds per square inch; and a 
chimney. The crushing plant comprizes a Carr-type disinteg- 
rator, 4 feet 6 inches in diameter, driven by a Tangye engine, 
with a cylinder 13 inches in diameter and 26 inches stroke, 
developing 42^ horsepower, under full load, when running at 
90 revolutions per minute. About 25 tons of slack aie crushed 
per hour, but this quantity can be increased if necessary. Elec- 
tric power is supplied by a steam-turbine, running at 3,000 
revolutions per minute, coupled direct to a continuous-current, 
compound-wound dynamo producing 50 kilowatts at 110 volts. 
The current is taken to the 38 horsepower motor, actuating the 
travelling gear and ram in the travelling charging-machine ; to the 
8 horsepower motor, working the stampers ; and to the 15 horse- 
power motor, elevating the slack into a storage-tower of 450 tons 
capacity. The arc and incandescent electric lamps, lighting the 



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A BTE-PEODrCT COKING-PLANT AT CLAY CEOSS. 



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890 A BYE-PRODUCT COKING-PLANT AT CLAY CROSS. 

works, axe supplied from the same source. Tke plant occupies 
a total area of about 2 acres of land, situated inside tke works 
of the company, and within 600 feet of the blast-furnaces. Figs. 
1, 2 and 3 show the general arrangement of the plant. The ovens 
are constructed on the Fabry-Linard principle : each oven being 
32 feet 9 inches long, and 20^ inches wide at the charging end, 
tapering to 22 inches at the discharging end. The height at the 
springing of the arch is 6 feet, and at the crown of the arch 
6 feet 7 inches. 

The slack for coke-making, taken from the Black-shale and 
Tupton mines, is sent from the various pits belonging to the com- 
pany to a central station where it is washed in a Barraclough 
washery. This machine is of the pulsating type, the dashers or 
pistons being attached to a horizontal shaft, working through a 
stuffing-box on the side of the washer-tank. The pistons, 20 inches 
in diameter and 6 inches stroke, make 68 strokes per minute. 
From 10 to 12 per cent, of dirt is washed out. The washed slack, 
delivered in railway-wagons at the crushing-plant, is emptied 
into a hopper and raised by an elevator to the disintegrator, 
where it is crushed and drope down into a hopper to be raised 
again by an elevator into a storage-chamber. 

The bottom of the storage-chamber is arranged with sliding 
doors, through which the slack is drawn into charging wagons on 
rails at the level of the top of the ovens. The pear-shaped wagons, 
holding about 32 cwts. of slack, are emptied into a hopper, car- 
ried on the charging machine. The contents are then emptied 
into the charging and compressing box, which has a capacity 
of 8^ tons: the charge of each oven. The charging and com- 
pressing box is made of the same length, width and height as 
a coke-oven. The slack is compressed in layers by means of 
electrically-driven stampers. There are two stampers, each 
weighing 400 pounds, travelling backwards and forwards by an 
automatic arrangement over the whole length of the charge. 

As soon as the slack is compressed to a sufficient solidity, the 
machine travels behind the coke-ovens to the oven about to be 
drawn; the oven- doors are then lifted by hand-winches (fig. 1, 
plate xii.), and the ram is set in motion. This ram pushes out 
the coke, and, on being drawn back, the machine is moved about 
3 feet so afi to bring the charging apparatus into line with the 



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A BYE-PEODUCT COKING-PLANT AT CLAY CEOSS. 



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892 A BYE-PEODUCT COKING-PLANT AT CLAY CROSS. 

oven. The compressed slack is then pushed forward into the 
oven on a forged-steel plate, forming the bottom of the compress- 
ing box •, the doors at each of the ovens are closed, and the plate 
is drawn back, leaving the slack in the oven. The travelling 
compressor is then moved back to the charg^ng-place, where it 
is again filled ready for the next oven. The whole of the 
machinery is actuated by continuous-current motors; and since 
the ovens have been started, now 18 months, there has scarcely 
been a hitch in the working of this machine. The time occupied 
in filling, compressing, removing to the required position, draw- 
ing the coke, re-charging the oven, and returning to the point 
at which the slack for a further charge is taken into the machine, 
is on an average something less than 35 minutes. The time 
occupied in coking averages 36 hours. 

Considerable difficulties were experienced at first in the 
quenching of the coke. This has now been overcome, and the 
quenching is effected by water at a pressure of 40 pounds to 
the square inch. In the opinion of the writer, the higher the 
pressure at which the quenching water can be discharged the 
better. The coke is pushed out of the oven on to a platform 45 
feet in length, with an inclination of li inches to the yard. The 
hose-pipe is played on to the coke from both sides during its dis- 
charge from the oven ; and the coke then stands upright in a 
mass. A 2 inches wrought-iron pipe is then connected to the 
hose-pipe, this pipe being bent in the form of an inverted U 
with the opening pointing downwards ; and it is moved along 
the whole length of the coke. After this watering, the mass of 
coke divides in the centre longitudinally, and is pulled over by 
the men ; and the rest of the required quenching is carried out by 
hand. When cooled, the coke is loaded by forks into steel 
barrows, and from these it is filled into wagons, the tops of which 
are level with tJie bench. 

The gas generated in the process of coking the slaek is drawn 
through a pipe, E, 12 inches in diameter, fixed midway on the oven 
(fig. 1, plate xii.). This pipe then delivers into a dry gas-main 
connected with the exhausters of the bye-product plant through 
the various coolers. The return-gas, used to heat the ovens on its 
way back from the bye-product plant, is divided into two mains, 



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A BYE-PE0DT7CT COKING-PLANT AT CLAY CROSS. 398 

A and Ai, carried the full length of the battery, one on the front 
of lihe oven and the other at the back. Connections are made 
from these mains to each heating-flue by means of pipes, a, and 
^1, IJ inches in diameter, with nozzles entering the flues : nozzles, 
I and hi, are the main ga«-inlets, and e and Ci are additional inlets.. 
The gas from the upper or main nozzles, h and 61, passes along the 
flues, f and f^, until it is deflected downwards by a cross-wall, i, in 
the flue into the second flues, g and ^1. At this point, additional 
gas-inlets, d and d^, are provided ; the gas travels outwards and 
meets a fresh supply through the nozzles, c and Ci, and is again 
deflected downwards into the third and lowest side-flues, A and h^. 
It travels inwards again through the flues, h and Ai, and then 
into the flues, k and ki, underneath the oven. The gas from the 
charging end of the ovens passes from the centre of the sole- 
flue, Zi, outwards through a damper, m, and into the main collector- 
flue, C, extending the whole length of the ovens. The gas from 
the opposite end passes outwards from the centre of the sole-flue 
to the coke-bench end of the oven and then through a portway, o, 
into the sole-flue, Z, under the next oven. It traverses the whole 
length of this flue, and passes through a damper, m, into the 
collector-flue, C. It will be seen from this description that the 
gas, after entering the bottom flue, is divided by the cross-wall, i, 
one portion passing straight into the collector-flue, a distance of 
half the length of an oven, while the other portion, before it 
reaches the collector-flue, has to traverse the length of one-and-a- 
half ovens. Each bottom-flue being fitted with a damper, the 
amount of gas passing can be regulated so that both flues are 
kept at the same temperature ; and it has been found that any 
variation in wind-pressure can be neutralized by this arrange- 
ment. 

Air is admitted at two points, (1) round the main gas-nozzle, 
b and b^, and also through a grid, e and e^, at each end of the 
oven, the air passing down three openings to meet the gas in 
the top side-flue, f and fi. 

The expansion of the ovens after lighting was about 1 in 144. 

The quantity of coke produced per week by the 50 ovens is 
1,100 tons, each oven producing about 22 tons. The yield of 
coke is 67| per cent., calculated from the dry slack after being 
washed. The slack contains 32J per cent, of volatile matter, and 

VOL. XXZI1I.-1906.1907. 29 



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894 



A BYE-PEODUCT COKING-PLANT AT CLAY CROSS. 



the average quantity of moisture in the slack, when put into the 
ovens, varies from 12 to 15 per cent. Analyses are made two or 
three times a day from samples of the slack, taken as delivered 
into the ovens. It may be considered that 15 per cent, of mois- 
ture is somewhat high, but the quantity has been determined 
after experiment; and it is found that the largest and best 
coke physically is produced from slack containing from 12 to 15 
per cent, of water. An average analysis of* the coke is as 
follows: — Fixed carbon, 8530 per cent.; ash, 10'20 per cent.; 
volatile matter^ 100 per cent. ; sulphur, 1*50 per cent. ; and 




Fio. 6.— North Side of Byk-peoduct Plant. 

moisture, 200 per cent. The coke is used in the Clay Cross 
blast-furnaces, and the balance is sold for blast-furnace purposes. 
It is a very good coke. The proportion of breeze is 1 per cent. 

No trouble has ever been experienced in the working of the 
ovens since the commencement, except on one occasion, shortly 
after they were originally started, when the heat was lost for a 
few hours. This occurred when the ovens were first connected 
with the bye-product plant, as for the first week the ovens were 
worked without the bye-product plant ; but since that time there 



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A BYE-PEODUCT COKING-PLANT AT CLAY CROSS. 



895 



has not been a hitch of any sort. Nothing has been spent in 
repairs to the ovens, and they show at present no sign whatever 
of any deterioration. 

The number of men employed in connection with the coke- 
burning is 20 on each shift, and it is, of course, scarcely neces- 
sary to say that the ovens are working continuously throughout 
the year. 

Bye-product Plant. — The bye-product plant is erected at the 
eastern end of the ovens, there being an open space of 30 feet 
between the ovens and this plant. The plant is arranged in the 



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Fig. 7.— East Side of Bte-pboduct Plant. 

form of a hollow square, the various coolers, scrubbers, etc., on 
the four sides and the large underground tank for the tar and 
ammoniacal liquor in the centre. 

The temperature of the gas leaving the ovens is 482^ Fahr. 
(250^ Cent.). From the dry gas-main an inclined pip© conveys 
the gases to the bottom of the first air-cooler. This pipe is ex- 
tended and left open, the open end being closed by dipping into 
a small water-tank; the gases pass in succession through two 
air-coolers ; a serpentine cooler, which can be used either as an 
air or 4s a water-cooler ; three water-coolers ; a tank in which the 



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896 A BTE-PEODUCT COKING-PLANT AT CLAY CKOSS. 

remainder of the tar is caught; and thence to the gas-exhauster 
in the enginehouse. There are two exhausters, one of which is 
used and the other forms a duplicate, driven by horizontal 
steam-engines. Steam is conveyed to these engines and for 
other puiposes to the bye-product plant in pipes from the boilers, 
which axe situated at the other end of the coke-ovens. These 
engines drive, by a countershaft, various belt-driven water, tar 
and ammoniacal-liquor pumps. The exhausters maintain a 
partial vacuum of 5 inches of water. After leaving the exhauster, 
the gases pass through a Pelouze-Audouin separator, which ex- 
tracts any remaining trace of tar; and then through a serpentine 
water-cooler to two scrubbers, where the gases entering at the 
bottom meet, in rising, a stream of falling water which is broken 
into spray by a number of wboden hurdles placed IJ inches apart 
across the scrubber; thence the gases pass through a gasometer; 
a water-seal tank to prevent an explosion at the ovens from 
reaching the bye-product plant ; and so back to the ovens. 

The ammoniacal liquor from the scrubbers, being carried into 
the large tank in the centre of the plant, is pumped into stills, 
where the free ammonia is liberated from the liquor by coming into 
contact with steam, and the fixed ammonia is liberated by treat- 
ment with lime. The ammonia gas is then conducted by pipes 
into a sulphuric-acid bath, where it is converted into sulphate of 
ammonia. And after the sulphate has passed through a centri- 
fugal dryer, it is stored ready for sale. The average weight of 
sulphate of ammonia produced per ton of slack coked is 32 
pounds. 

The tar, collected into the central tank, is pumped into an 
elevated tank, from which it is run into railway tank-wagons. 
The weight of tar produced is 67J pounds per ton of coal car- 
bonized. The tar is sold in the crude state to refiners, as it was 
not considered worth the expense of erecting a plant to deal further 
with that bye-product. 

The cooling water necessary for the recovery of bye-products 
from the 50 ovens is approximately 4,500 gallons per hour, at a 
temperature not exceeding 63^ Fahr. 

After the waste-gases have passed from the ovens, as previously 
described, they are conveyed to the boilers. These are evaporat- 
ing 500 gallons of water per boiler per hour, the pressure of the 
steam being 100 pounds per square inch. The steam is utilized 



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A BYE-PEODUCT COKING-PLANT AT CLAY CROSS. 897 

for the coal-crushing plant, for the steam-turbine, and in the bye- 
product works. The surplus steam is used to drive the fitting- 
shop- and foundry engines, at a distance of some 600 feet from 
the boilers. 

The company supply a considerable area round their works 
with gas, making on an average some 50,000,000 cubic feet a 
year. It was found that the waste-gases from the ovens were in 
excess of that required for the generation of steam, and a main 
was laid from the ovens to the g^as- works, a distance of about* 
i mile. A meter was fixed at the end of the main, near the coke- 
ovens, and the gas is conveyed from the coke-ovens to the gas- 
works, entering the purifiers and mixing there with ordinary 
coal-gas manufactured at the gas-works. It has been found that 
this gas is a good iUuminant, with a candle-i)ower, when used by 
itself, of 14J ; when mixed, however, with ordinary coal-gas, the 
candle-power is raised to 17 before distribution to the public. This 
has been found to be perfectly satisfactory, and has proved an 
economy both in coal-consumption and in labour. 



The Chaiehan (Mr. J. C. Cadman) moved a vote of thanks to 
Mr. W. B. M. Jackson for his interesting paper. 

Mr. Isaac Hodges seconded the resolution, which was cordially 
approved. 



Mr. A. Victor Koch's "Notes on Bye-product Coke-ovens, 
with Special Reference to the Koppers Oven" was read as 
follows : — 



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898 NOTES ON BYE-PEODUCT COKE-OVENS. 



NOTES ON BYE-PRODUCT COKE-OVENS, WITH SPECIAL 
REFERENCE TO THE KOPPERS OVEN. 



By a. victor KOCHS. 



Introduction, — The main object of this paper is to explain 
the design and construction of the bye-product coke-oven in- 
vented by Mr. Heinrich Koppers, of Essen, Germany, and to 
point out the special features which distinguish it from other 
systems. But, as coke-ovens of the kind have not been employed 
in this country to any considerable extent, the construction and 
the working thereof are comparatively little known to colliery and 
iron- works engineers, and it has therefore been thought that a few 
preliminary remarks on the general design and advantage of this 
type of oven would not be out of place. 

The introduction of the original non-bye-product retort-oven 
had for its object the acceleration of the carbonizing process by 
employing the gases of distillation for heating the oven-walls; 
which was not previously the practice with beehive ovens. The 
long rectangular form of the oven, was, of course, chosen to 
enable the coke to be mechanically discharged from the oven. 
The step from the ordinary retort-oven to the bye-product oven 
was a simple and natural one, and it is a matter of great surprise 
that up to the present so few plants have been erected in this 
country. All coke-oven builders are practically of the same 
opinion as to the general shape of the ovens ; and it is principally 
in regard to the method of heating the ovens and the arrangement 
of the heating-flues, which are, of course, the most important 
points to be taken into account, that the various ovens differ 
one from the other. 

The main points of difference between the several systems 
of ovens may be summarized as follows : — (1) The arrangement of 
the heating-flues; (2) the facilities for inspecting the heating- 
flues; (3) the method of applying and regulating the heating- 
gafies; and (4) pre-heating the air for combustion. 



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NOTES OX BYE-PRODrCT COKE-OVENS. 899 

Heating-flues. — ^The ideal requirements of bye-product coke- 
ovens are quite obvious, and may be concisely stated to be the 
uniform heating of the oven-walls along the whole length of 
the ovens, combined with easy and perfect means for inspecting 
the working of the ovens and for regulating the combustion. In 
order to attain these requirements, many designs have been 
brought out, showing various arrangements of heating-flues, but 
there now seem to be only two flue-arrangements which have 
survived, namely, the vertical and the horizontal. Of these two 
designs, it can safely be stated that the vertical flue has been by 
far the most popular, as the great bulk of the ovens which have 
hitherto been built are of this construction. It might be men- 
tioned that the employment of horizontal-flued ovens has in Ger- 
many been practically abandoned. 

It is claimed for horizontal flues that they permit of the 
working of the ovens being better supervised and controlled, 
owing to the facilities provided for inspecting the heating-flues 
whilst the ovens are at work. This is certainly an advantage 
over ovens in which the heating-flues cannot be examined. The 
great function of the flues, namely, to heat the oven-walls uni- 
formly, is, however, in the writer's opinion, sacrificed to attain 
this object, as it is evident that to heat uniformly a chamber 33 
feet long, it is absolutely essential that the side-walls be heated 
at the greatest possible number of points with jets of equal 
intensity. The construction of horizontal-flued ovens will not 
permit of more than three or four jets being employed at each 
end of the oven ; and it is quite evident that the walls cannot be 
so equally heated as the walls of vertical-flued ovens having a 
large number of heating jets distributed along the whole length 
of the oven. This will be clear when it is borne in mind that 
the greatest heat of a flame is a little beyond the point of com- 
bustion, and it is, therefore,* obvious that the walls of horizontal- 
flued ovens are overheated at the few points of ignition of the gas 
and air, whilst the other portions of the wall are comparatively 
cool. In horizontal-flued ovens, furthermore, the top flue is 
heated to a high degree, and it is generally admitted that this is 
a disadvantageous feature, as the great heat has the effect of 
decomposing the gases of distillation and entailing a consequent 
loss of bye-products. With vertical-flued ovens, on the other 
hand, the greatest heat is generated at the lowest point of the 



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400 NOTES ON BYE-PBODUCT COKE-OVENS. 

oven ; and the top portion of the oven is much cooler, there being 
a difference of from 200<^ to 300^ Cent. (392o to 572^ Fahr.) be- 
tween the temperatures at the top and bottom of the oven. 

Some ovens of the horizontal-flue type are arranged with a 
dividing-wall between each oven; and it is commonly supposed 
that the provision of this wall is an advantage, in that it acts as a 
store for heat and prevents the temperature of an oven from being 
affected when the next oven is freshly charged with coal. This 
theory, in the writer's opinion, has no foundation in fact ; but, on 
the contrary, the central wall is a distinctly disadvantageous 
feature, because it necessitates the provision of double the number 
of flues, which has the effect of extending the length of a battery 
of ovens by from 60 to 100 per cent, and thus increasing the 
area of heat-radiation to that extent. The heat lost by radia- 
tion in a battery of ovens with single-flued walls is calculated 
to be about 25 per cent, of the total heat supplied to the ovens ; 
and as the radiation of heat is directly proportional to the surface 
exposed, it necessarily follows that heat will be lost in the same 
ratio as the battery is extended. Any advantage that the wall 
may have as a store for heat would therefore obviously be lost. 
It is true that the wall serves to prevent the temperature of an 
oven from being affected when the next oven is freshly charged. 
This, however, is no advantage over ovens having single-flued 
walls, as experiments have indisputably established the fact that 
no appreciable difference in temperature takes place in a single- 
flued oven when its neighbour is freshly charged. Even if such 
a difference of temperature took place, no loss in heat would occur, 
as any heat extracted would assist the carbonization of the coal in 
the cold oven. It might be added that the provision of a central 
wall cannot very well be dispensed with in ovens having horizontal 
flues, if air heated in the basement of the ovens is to be employed 
for combustion-purposes ; as it is only by means of flues in the 
central wall that the hot air can be conducted to the points of 
combustion. The provision of a central wall is, furthermore, 
essential with ovens having horizontal flues, in order to afford 
sufficient support for the superstructure : it being quite evident 
that a wall formed of single-horizontal flues could not be re- 
garded as being otherwise than a very weak construction. "Walls 
of vertioal-flued ovens, on the other hand, consisting, as they do, 
of a series of hollow columns of brickwork, are of very strong 



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NOTES ON BYE-PEODUCT COKE-OVENS. 401 

coDfitruction ; and there is, therefore, absolutely no necessity for 
providing a central wall with a view to increasing the strength. 

Regvlation of Working. — The next most important point 
which should be taken into consideration is the method of regu- 
lating the working of the ovens. The main object aimed at in 
the construction of coke-ovens is the production of a homogeneous 
coke ; and, as this is only possible when every part of the charge is 
subjected to the same temperature, it is essentially necessary, 
not only that the oven should be heated at the greatest number 
of points along the whole length of the walls, but that each jet 
should be capable of easy regulation. In a number of ovens, 
the regulation has to be effected wholly from the galleries 
beneath the ovens, where the heat renders the work very uncom- 
fortable; in consequence of which the regulation is neglected 
and, therefore, not properly performed. It happens in all ovens, 
from time to time, that dark places appear in the walls, indicat- 
ing either that the flues are choked up or that the gas or air- 
admission requires adjustment. Such defects in the heating 
should be rectified immediately, and if the adjustment cannot 
be effected without trouble and discomfort, the workmen will not 
seek to remedy the defects. It is, therefore, quite evident how 
absolutely necessary it is that all means of regulation and adjust- 
ment should be easily accessible, in order that the heating can be 
controlled without any difficulty or discomfort. 

Pre-heating of Air. — ^A point of great importance is the pre- 
heating of the air for combustion. The higher the temperature to 
which the air is raised, the less is the quantity of gas required for 
generating the necessary heat for carbonizing the coal. By 
raising the temperature of the air to the highest attainable degree 
(1,0000 to 1,100° Cent., or 1,832 to 2,012° Fahr.) by means of 
regenerators, only from 46 to 56 per cent, of the total quantity 
of gas evolved from the coal is required for heating the ovens, 
the remaining quantity being available as a surplus for external 
purposes. In nearly all systems of ovens, the air is heated by 
conducting it through the galleries under the ovens and through 
air-channels formed in the brickwork-foundations of the ovens ; 
but the heat thus gained is of no great value in enabling surplus 
gas to be produced in any quantity. In fact, in a number of 



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402 NOTES ox BYE-PEODUCT COKE-OVENS. 

cases it has been foimd impossible to carbonize coal in ovens 
where the air is heated only by such means ; and ovens arranged 
with regenerators have had to be adopted, as the entire surplus 
heat in the coal is produced in such ovens in the form of a com- 
bustible gas, the whole of which is available if necessary for 
heating the ovens. Ovens working without regenerators, on the 
other hand, produce the surplus heat in the coal mainly in the 
form of a hot waste-gas, which can only be used for boiler-firing 
and could not be made use of in any way for assisting the car- 
bonizing process. 

Development of the Koppers Oven, — The Koppers oven is ar- 
ranged with vertical flues, and is a development of the old Otto- 
Hoffmann oven, which, for about 20 years, was the most popular 
oven on the Continent. The Otto-Hoffmann oven was, however, 
essentially a regenerator-oven, whilst the Koppers oven can be 
arranged to work with or without regenerators. The main feature 
of the original Koppers oven, in which it differed from the Otto- 
Hoffmann, was the separate distribution of gas and air, and 
causing combustion to take place in each separate flue along the 
whole length of the oven. This improvement had the effect of 
compelling the gases of combustion to pass up each flue instead 
of making their way up any flue according to the line of least 
resistance, as was the caae with the old Otto-Hoffmann oven. The 
distribution of the heating thus effected was found to be a great 
improvement ; but it was also found necessary, in order to be able 
to arrive at perfect uniformity in the heating of the walls, for 
each of the gas-inlets to be accessible for regulation. Openings 
were therefore subsequently made in the top of the ovens, one 
over each flue, by means of which the gas-admission nozzles could 
be taken out and replaced with the least possible trouble. The 
next step in the development of the oven was the provision of 
regulating sliding-bricks over each flue, which are accessible for 
adjustment through the openings at the top of the ovens previ- 
ously referred to. Through the agency of these sliding-bricks 
the quantity of air entering each flue can be regulated to a 
nicety, and, in practice, it has been found to be a most important 
advantage. 

Bye-product ovens which produce the surplus heat in the coal, 
that is the heat over and above that required for carbonizing the 



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NOTES ON BYE-PRODrCT COKE-OVENS. 408 

coal, mainly in the form of a hot waste-gas, are not distinguished 
in this country by any particular name from those which produce 
the surplus heat wholly in the form of a combustible gas. In 
Germany, the name given to the former type of oven is Abhitze 
Of en (waste-heat oven), whilst the latter is known by the name 
Regenerativ Of en (regenerator-oven). As there is a distinct 
difference between the two systems, and the Koppers oven is 
designed on both principles, they are distinguished by the 
designations of waste-heat oven and of regenerator-oven. 

Koppers Waste-heat Oven, — Plate xiii. shows longitudinal and 
cross-sections through the oven-chamber and heating-flues. Fig. 
1 is a longitudinal section through one of the walls and shows 
the arrangement of the heating-flues; fig. 2 is a longitudinal 
section through the oven-chamber; and fig. 3 shows three 
different cross-sections through a number of ovens. The oven 
is a chamber 32 feet 10 inches (10 metres) long, 6 feet 7 inches 
(2 metres) high and from 20 to 24 inches wide in the centre. The 
height and the width, however, vary somewhat according to the 
class of coal to be coked. The top of the oven is provided with 
three openings. A, for charging the coal, and a fourth opening, B, 
through which the gases of distillation are drawn off to the con- 
densing plant. The purified gas is returned from the bye-product 
plant by the main, C, placed in a position convenient for access, 
either in front of or at the back of the battery of ovens. Separate 
branch supply-pipes, D, fitted each with a regulating-cock, con- 
duct the gas to each oven ; and these branch pipes communicate 
with the gas-distributing channel, E, placed immediately below 
the heating-flues. This channel, E, is formed of fire-brick pipes, 
and runs along at the base of the whole of the heating-flues, with 
the exception of one or two at the end remote from that at which 
the gas is admitted, and these latter flues conduct the waste- 
heat to the main flue, P, leading to the steam-boilers. The 
heating gas passes out of the distributing channel through orifices 
each fitted with a gas-nozzle communicating with each vertical 
flue. The air for combustion flows along the conduit, F, and 
induced by the chimney-draught it is drawn into the air-distribut- 
ing channels, G, situated immediately beneath the oven-cham- 
bers. The air enters each heating-flue through the openings, H, 
and meets the gas issuing through the gas-nozzles, TJ. Com- 



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404 NOTES ON BYE-PRODUCT COKE-OVENS. 

bustion takes place a little above the nozzle, and it is to be 
particularly noticed that the comparatively cold air flows 
around the base of the nozzle (fig. 5, plate xiii.), keeps it cool, and 
prevents any likelihood of the nozzle setting fast. The products 
of combustion of the gas and air pass up the heating-flues, K, and 
through the openings, L, at the top of each flue. These openings 
are each furnished with a damper, M, which can be easily regu- 
lated so as to enable the exact amount of air to enter the flue 
necessary to effect perfect combustion. The sliding-bricks are 
accessible from the top of the ovens through the openings, N, 
which are fitted with easily removable plugs (fig. 4, plate xiii.). 

At this point, particular attention should be directed to the 
sliding-bricks and to the openings at the top of the ovens which 
give access to them, as these are two of the principal features of 
Koppers ovens and distinguish them from all other constructions. 
The openings at the top of the ovens serve not only to provide 
means for regulating the dampers, but serve more particularly to 
give access to the gas-nozzles, TJ, and they further permit of the 
flues being inspected at any time. Without the facility thus pro- 
vided for examining the flues, it would not be possible to work 
the ovens satisfactorily. The gas-nozzles are furnished with oval 
orifices, to enable them to be taken out by a rod having a tee end 
as shown in fig. 6 (plate xiii.). The orifices in the nozzles vary in 
size, according to their position in the flues. The removal and 
replacing of a nozzle can be effected in a few moments, without 
the slightest trouble or discomfort. 

As already mentioned, it happens from time to time in all 
ovens that dark places appear in the oven-walls indicating that 
the combustion is defective ; and, in the absence of means of ac- 
cess to the flues, it would be necessary to cool down the oven and 
break into the walls in order to remedy the defect. By means of 
the openings over each flue in the Koppers oven, the cause of any 
irregidarity in the heating can be immediately detected, and in 
the great majority of cases such defect could be rectified in a 
few moments. The effect of any adjustment in the regulation of 
the gas and air can, moreover, be seen immediately ; whereas in 
other ovens the effect of any alteration in the gas or air-supply 
can only be ascertained after the lapse of some time, and then 
only by the appearance of the wall inside the oven after the 
coke has been discharged. 



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NOTES ON BYE-PKODUCT COKE-OVENS. 



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406 



NOTES ON BYE-PRODUCT COKE-OVENS. 



Other oven-builders, in endeavouring to provide similar facili- 
ties for regTilating the combustion in the flues, have adopted 
means of adjustment at the base of the flues, to which access is 
obtained from the basement of the ovens. It has already been 
pointed out that the heat in the galleries beneath the ovens is 
too great to permit of the work of regulation being carried out 
without great discomfort. Apart from this the throttling of 
the air-inlets at the base of the flue has the effect of increasing 
the velocity of the air, so that the speed of the gases of com- 
bustion up the heating-flues would be unequal along the length 
of the oven, and the heating cannot, therefore, be uniform. 




Fig. 19.— Koppebs Coke-ovens, Barnslbt Main Colliery. 

After passing through the openings at the top of the heating- 
flues, the gases of combustion flow along the horizontal flue, 0, 
in the direction indicated by the arrows (fig. 1, plate xiii.), 
and finally pass down into the main fine, P, leading to the boilers. 
The outlet-fiue from each oven is furnished with a regulating- 
damper, R, by means of which the chimney-draught is adjusted. 

It will have been seen that each oven-wall is formed of about 
thirty vertical fines, and that each of these flues is provided with 
a heating jet and also with means for regulating the admission of 
the gas and air, namely, by substituting the gas-nozzles, and by 



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NOTES ON BYE-PRODUCT COKE-OVENS. 407 

adjusting the sliding-bricks over each flue respectively. It is, 
therefore, obvious that it is easily possible to control the heating 
SO that the oven-walls will be subjected to exactly the same tem- 
perature from end to end. This uniformity in the heating has 
been striven after by coke-oven builders for many years, as it is 
the ideal requirement; and, unless it be attained, it is impos- 
sible to produce a coke which will be homogeneous in character 
throughout the charge. 

Experience has shown that it is a great disadvantage for the 
upper part of the oven- walls to be heated to an intense degree (as 
is the case with horizontal-flued ovens), as the gases of distillation 
become decomposed by the heat, which results in a loss of bye- 
products. In the Koppers oven, the zone of greatest heat is oppo- 
site the bottom of the charge of coal, and by the time that the 
gases of combustion reach the upper part of the oven the tempera- 
ture is so much reduced that they will have no detrimental effect 
on the gases of distillation. 

Besides the production of a homogeneous coke, the uniform 
heating of the ovens possesses another most important advantage, 
namely, that it enables the period of coking to be reduced, which 
results in an increased yield of coke. This will be evident when 
it is considered that, in ovens where the walls are more intensely 
heated at some points than at others, parts of the charge become 
carbonized sooner than the portion in the cooler part of the 
ovens, but the charge has to remain in the ovens until the whole 
is carbonized. It follows therefore that, with perfectly equally- 
heated walls, the carbonization of the whole charge is completed 
at the same time. 

Koppers Regenerator-oven. — ^The Koppers regenerator-oven is 
designed on identical lines to the waste-heat oven, and differs only 
in that the air for combustion is heated to an intense degree by 
means of regenerator-chambers. The advantages of equal heat- 
ing, easy means of regulating, and the facilities for inspecting 
the flues, which distinguish the waste-heat oven over other sys- 
tems, are the same in the regenerator-oven. 

The form of regenerators which was originally employed with 
the Koppers oven consisted of two long chambers filled with a 
chequer-work of fire-bricks, running the whole length of the 
battery of ovens in the position shown in figs. 7, 8 and 9 (plate 



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408 NOTES ON BYE-PEODUCT COKE-OVENS. 

xiv.). The air for combustion enters at the end of one regenera- 
tor, and passes to each oven through the openings, W. After 
ignition with the gas in the heating-process of the oven, the 
resulting products of combustion pass through the heating-flues 
to the other regenerator, and, induced by the chimney-draught, 
they pass along to the chimney, giving up their heat to the 
chequer-work of fire-bricks. After a period of time, usually 
about 30 minutes, the air which entered the first regenerator has 
abstracted the heat from the chequer-brickwork; whilst the 
bricks in the other regenerator have been raised to an intense 
heat by the waste-gases going to the chimney. The direction of 
combustion is then reversed by automatic means, the air being 
admitted into the highly heated regenerator; and the products of 
combustion pass through the other regenerator, which again 
becomes heated to an intense degree. The air is heated to a 
temperature of about 1,100° Cent. (2,012<^ Fahr.), whilst the heat 
of the waste-gases is absorbed by the fire-brick chequer-work, to 
such a degree that the gases are quite black on entering the 
chimney and are useless for any further purpose. 

In order to avoid the trouble and inconvenience which may 
be experienced through repairs having to be carried out in con- 
nection with the regenerators (which would always necessitate 
the whole battery of ovens being shut down), an oven was designed 
and patented by Mr. Koppers in which separate regenerator- 
chambers are provided for each oven. A large number of ovens 
of this construction have been erected, and have proved a great 
success. The new construction has a number of important 
advantages over the older form, apart from rendering the ovens 
independent of each other: the principal one is, that it permits of 
a better regulation of the air and of the draught for each oven. 
This point will be explained more fully later on. Another 
advantage is that the substructure is of a simple character, and is 
less liable to be affected by the expansion of the brickwork. A 
further advantage is that it enables the hot air to be still more 
satisfactorily distributed amongst the heating-flues. 

Figs. 10, 11 and 12 (plate xv.) show longitudinal and cross- 
sections through the latest Koppers regenerator-oven and figs. 7, 
8 and 9 (plate xiv.) similar sections through the former type of 
regenerator-oven. The working of the two systems is identical in 



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NOTES ON BYE-PRODUCT COKE-OVENS. 409 

all respects, and differs only in the arrangement of the regener- 
ators. The lettering in the two plates is accordingly the same, and 
the following description can therefore be taken as appljring to 
either construction. 

The air for combustion flows along the passage-ways, A, at 
the front and back of the ovens, and thence it passes into the 
regenerators through the inlets, B. In the regenerators, the 
temperature of the air rises to 1,000<^ Cent. (1,8320 Fahr.). The 
highly heated air passes out of the regenerators into the vertical 
heating-flues through the openings, C. The purified gas from 
the bye-product plant is returned to the ovens by the mains, D, 
running along the whole length of the ovens on each side. 
Branch supply-pipes, H, conduct the gas into the gas-distributing 
channels, E, which are situated directly beneath the oven-walls; 
thence it passes through the gas-nozzles, F, into each vertical flue, 
where it ignites with the hot air entering through the passages, C, 
previously referred to (fig. 13, plate xv.). A jet is therefore formed 
on a level with the oven-floor in each of the heating-flues of the 
oven-chamber, in which respect it will be seen that the heating is 
identical with that of the waste-heat oven already described. 

The employment of regenerators renders it necessary to 
reverse the heating-process after a period of time, usually about 
30 minutes ; and the heating-flues are divided into two sections, 
80 that combustion can take place alternately in each half of the 
oven-wall. When the gas is burning in one half of the wall, 
the products of combustion pass up the flues and enter the top 
horizontal flue, G, whence they make their way down the flues 
in the other half of the oven-wall, and enter the regenerator 
through the same passages, C, by which the air is admitted to 
the flues when the direction of combustion is reversed. On 
issuing from the regenerator, the waste-gases pass into the flue 
leading to the chimney, after having given up their heat to the 
chequer-work of fire-brick. 

It should be here pointed out that the same means of regu- 
lating the combustion in each separate flue and of obtaining 
access to the flues, are provided as in the case of the waste-heat oven 
<figs. 1, 2 and 3, plate xiii.) ; and the oven therefore possesses the 
same advantages as regards uniform heating and easy regulation. 

It has been stated by interested parties that the walls which 
divide the regenerator-chambers in the Eoppers new system, 

TOL. XXXIII.— 1M6-If07. 30 



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410 NOTES OX BYE-PRODrCT COKE-OVENS. 

having to support the ovens and the superstructure, are of insuffi- 
cient strength owing to their being in a kighly heated condition. 
It should therefore be mentioned here that the total sectional 
area of the walls is two-thirds of the whole surface upon which 
a battery of ovens is built. The walls in no case would be sub- 
jected to a greater temperature than 1,100^ Cent. (2,012<^ Fahr.) : 
and, as the walls in a cool state are easily capable of supporting a 
load 100 times the weight that they have to bear, it is abundantly 
evident that they will be more than amply strong enough to 
carry the load at the temperature stated. 

It might, furthermore, be pointed out that the cubical con- 
tents of the new regenerator-chambers are from three to four 
times that of the ordinary construction; and that, notwith- 
standing this great increase in capacity, there is, if an3rthing, 
less chance of heat being lost by radiation owing to the protected 
position in which they are placed. 

Mention has been made that the employment of separate re- 
generators for each oven enables the supply of air and the 
chimney-draught to be better regulated than is possible with 
the old form of regenerators. On referring to figs. 7, 8 and 9 
(plate xiv.) it will be seen that there is a regulating damper over 
the passage leading from the regenerator-chambers to the air- 
distributing channel. This damper has to be set to serve the 
dual purpose of regulating the admission of air when the ovens 
are burning in one direction, and of regulating the chimney- 
draught when the ovens are burning in the reverse direction. It 
is not possible to effect a satisfactory regulation of both the air 
and the draught by means of only one damper. 

Figs. 14, 15, 16 and 17 (plate xvi.) show the new means of 
regulation, as also the arrangements for reversing the combustion. 
Figs. 14 and 16 show, respectively, longitudinal and transverse 
views of the gas and air-supply fittings on the side of the oven 
where the gas is burning ; whilst figs. 16 and 17 show the corre- 
sponding arrangements on the other side of the ovens where the 
waste-gas is passing to the chimney. The gas is supplied to each 
oven by the branch pipes, H, which are each provided with a regu- 
lating-cock, K, as well as with a second cock, Ki, fitted with a lever. 
All the levers are attached to one of the wire-roi)es, Li, which lat- 
ter communicate with the automatic changing-gear. The air is 



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NOTES ON BYE-PRODrCT COKE-OVENS. 411 

admitted to each oven by means of the cast-iron damper-fitting, 
M, which also serves to conduct the waste-gases to the chimney- 
flue, XJ. These dampers are each fitted at the top with a slide, 
If, which are like the levers of the gas-cocks, all connected to the 
second wire-rope, La ; and the whole is so arranged that, when the 
automatic changing-gear oi)erate8, the gas-cocks and damper- 
slides on one side of the battery are closed simultaneously with 
the opening of the corresponding parts on the other side of the 
battery. When the gas is burning on the side of the ovens as 
shown in figs. 14 and 15, the air-damper is open, and the air 
passes into the regenerator in the direction indicated by the 
arrows, the main chimney-damper, P, being closed. A little 
below the damper-slide there is a second slide, B, which can be 
set in any desired position, and serves to regulate the quantity of 
air required for each oven. When the gas is burning on the 
opposite side of the oven, as shown in figs. 16 and 17 : that is, 
when the waste-gases are passing to the chimney, the gas-cocks 
and air-dami)ers are closed, but the main chimney-damper, P, is 
opened. The waste-gases are therefore drawn through the cast- 
iron damper-fitting, M, into the chimney-flue, TJ, in the direction 
indicated by the arrows. At the base end of the cast-iron fittings 
there is a third slide, S, which can be set in any desired position 
to regulate the draught on each oven. It will, therefore, be seen 
that, by the new arrangement, the quantity of air for each oven 
and the chimney-draught on each oven can be separately regu- 
lated, which is not possible with ovens working with the older 
form of regenerators. A very disadvantageous feature has thus 
been removed in the new system. 

The automatic changing-gear is a simple clockwork arrange- 
ment, and is placed at one end of the battery of ovens. It is 
electrically operated, and requires the least possible attention. It 
may be added that the gear is so designed that should anything 
fail to act, an electric alarm is set in action which does not stop 
until the gear is again at work. 

A discovery of more than ordinary importance has recently 
been made by Mr. Koppers, in regard to the regeneration of the 
air for combustion and the utilization of the waste-gases. It 
was found by observation and experimental tests that the heat 
of the waste-gases could not be reduced in the regenerators below 
a certain temperature, no matter of what capacity they were 



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412 XOTES ON BYE-PRODUCT COKE-OVEXS. 

made ; and the result of calculations showed that the whole of the 
heat in the waste-gases could not be extracted by means of re- 
generators. Mr. Koppers ascertained that this was due to the 
air only being regenerated, the gas being admitted in a cool 
state. The proportion of gas is from one-sixth to one-seventh of 
the quantity of air, and consequently the volume of the waste- 
gases is about IG per cent, greater than the volume of the air that 
it has to heat up. A loss of heat therefore took place by passing 
the whole of the waste-gases through the regenerators, and in 
the latest construction of the Koppers ovens means have been 
introduced to enable a portion of the waste-gases to be drawn off 
in a hot state for boiler-firing purposes. On referring to fig. 10 
(plate XV.) a vertical flue, T, in the centre of the heating-flues will 
be seen. By means of this flue a portion of the hot waste-gases 
passes into the central flue, Y, beneath the ovens, and is con- 
ducted to the boilers. A sliding-brick is placed at the top of the 
vertical flue, by means of which the quantity of waste-gases to 
be drawn off can be regulated. The reduced volume of the waste- 
gas which passes into the regenerators is sufficient to heat up the 
chequer-work of bricks to the same maximum temperature as 
when the whole of the waste-gases is passed through the regenera- 
tors ; and the air will accordingly be heated to the same degree 
when subsequently passed through, Jhe only difference being 
that the temperature of the waste-gases on entering the chimney 
is reduced to a lower degree than when the whole of the waste- 
gases pass through the regenerators. 

It will be gathered from the foregoing description that the 
new construction enables about 16 per cent, of the hot waste- 
gases to be saved at the expense of the gases passing into the 
chimney. The air being raised to the same temperature as in 
the older construction, no more combustible gas is required for 
heating the ovens ; and consequently the same amount of sur- 
plus gas is available. As already stated, the quantity of surplus 
gas from the Koppers regenerator-oven amounts to from 45 to 55 
per cent, of the total quantity evolved from the coal. The gas 
being in a combustible form, can be conducted almost any 
distance, and can be utilized for any purpose for which ordinary 
town illuminating-gas can be used. There is, therefore, no 
necessity for erecting a special range of boilers in close proximity 
to the ovens, as is necessary with waste-heat ovens. 



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NOTES ON BYE-PRODrCT COKE-OVENS. 



413 



Gas-engines, — The great advantage of recovering the surplus 
heat in the coal in the form of a combustible gas is that it can be 
employed for generating power in gas-engines, which enables 
about three times the power to be derived from it that can be 
obtained by consuming it under steam-boilers, or that can be 
generated by the hot waste-gas from waste-heat ovens. The sur- 
plus gas from a coal of average composition is sufficient to pro- 
duce a continuous supply of from 50 to 60 horsepower per oven. 
Another great advantage which combustible gas possesses over 




Fio. 20.— NDbnbero Gas-ekoinb of 1,200 Hobsepowbr, Barooed Colliery. 

hot waste-gas is that the former can be stored so long as it is 
not required ; whilst the latter must be used on the spot directly 
it is produced, and cannot be employed for any other purpose 
than boiler-firing. At most collieries, little power is required 
to be produced during the night-time and on Sundays; and at 
such times hot waste-gas would be lost, whilst combustible gas, 
on the other hand, could be stored in gas-holders and consumed 
during working hours. 



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414 



NOTES ON BYE-PRODUCT COKE-OVENS. 




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NOTES ON BYE-PBODTJCT COKE-OVENS. 415 

Great progress has been made in recent years on tlie Continent 
in the design of large gas-engines, and at a number of collieries 
in Germany large gas-engine power-installations have been put 
down in connection with coke-oven plants. Indeed, the great 
waste of power which formerly took place at coke-oven plants, 
through employing the surplus gas for boiler-firing, is respon- 
sible in a great measure for the development of the gas-engine. 
At a number of Koppers coke-oven plants erected in Germany 
and in this country,* large gas-engine central-power stations have 
been installed. As an example of the extent to which gas-engines 
are employed on the Continent, an interior view is given (fig. 21) 
of the gas-engine power-station at the Anna colliery of the Esch- 
weiler Mining Company, near Aix-la-Chapelle. At this col- 
liery, there are six batteries of Koppers regenerator-ovens, total- 
ling 342 ovens, and the power-station is designed for the pro- 
duction of 16,000 horsepower from the surplus gas. At present, 
engines having a capacity of 9,400 horsepower are in operation, 
whilst others are under construction. 

Until recently, gas-engines of high power were viewed with 
great disfavour in this country, as it was generally supposed that 
they could not be made to drive electric generators running in 
parallel with each other. This was the case at one time, but 
difliculty in this direction is no longer experienced. At two of 
the pits of the Rheinpreussen collieries, situated near Homberg, 
Germany, two large gas-engines have been driving, for a con- 
siderable time past, three-phase generators of about 1,300 kilo- 
watts capacity. The engines are situated several miles apart, 
and no trouble is experienced in getting them to work, not only 
in parallel with each other but with a steam-engine generating- 
set at a third colliery. At the Rheinpreussen collieries, it may 
be added, there are five batteries of Koppers ovens, totalling 225 
ovens, and the surplus gas is employed partly for driving the 
gas-engines. 

Conclusion. — In conclusion, reference should be made to the 
results obtained from the Koppers ovens. As the output of coke 
per oven depends to a great degree upon the character of the coal 
and is also dependent upon the sectional area of the oven itself, 
the results obtained from any particular plant ^ould not be 
taken into account. Generally speaking, however, the output of 



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416 DISCrSSION — notes on BYE-PRODrCX COKE-OVENS. 

coke, free from breeze, made from coal of average coking quality 
as raised in Westphalia and the Rhineland, is about 5*2 tons per 
oven per day, so that a battery of 50 ovens produces about 1,800 
tons of large coke per week. The yield of bye-products simi- 
larly is greatly dependent upon the character of the coal; but 
it is claimed for the Koppers oven that, owing to the uniform 
heating of the walls and to the fact that the zone of the greatest 
heat is at the bottom of the oven and therefore remote from the 
point where the gases pass out at the top of' the oven and where 
the volatile constituents would be decomposed by great heat, a 
higher yield of residuals is obtained than in other systems where 
similar conditions do not prevail. 

Before closing this paper, attention should be drawn to the 
great progress which the Koppers oven has made, since it was 
first brought out a little over four years ago, indicating clearly 
that the oven possesses advantages of more than ordinary 
character. 



The Chairman (Mr. James Cope Cadman) said that the 
subject of bye-products played a most important part in the 
successful working of collieries, and would do so to an even 
greater extent in the future. 

Mr. L. T. O'SiiEA said that Mr. Kochs' paper was exceedingly 
comprehensive with regard to many points of importance as to 
the manner in which Koppers ovens were conducted. In the 
Koppers oven, and others of similar construction, an attempt 
had been made to solve the great difficulty not only of the distribu- 
tion of the gases into the flues, but also that of the air used for 
combustion. It was necessary in order to secure the proper com- 
bustion of any gas that the proportion of air required to bum that 
gas should be carefully regulated. An attempt had been made to 
do this in the Koppers oven, and he thought that in this respect 
a considerable advance had been made. The pre-heating of the 
air for combustion deserved consideration, from the point of view 
of the use to which the gases were to be applied. If the waste- 
gases from the combustion-flues were to be used for generating 
steam, they should be as hot as possible, when they reached the 
boilers, in order to generate sufficient steam for use in the bye-pro- 
duct plant ; whereas if the generation of poyeer in an internal com- 



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DISCUSSION — ^NOTES ON BYE-PRODUCT COKE-OVENS. 417 

bustion-motor was the object in view, the waste-gases from the 
combustion-flues could not be used, but the surplus of combustible 
gas was important. Consequently, if the waste-gases were used for 
generating steam, the pre-heating of the air was not desirable, 
because the gases, which came away from the combustion-flues, 
would be left in a hotter condition than if some of the surplus 
heat was utilized before it passed to the boilers ; but if surplus 
combustible gas was required it would be considerably increased 
by pre-heating the air. He thought that Mr. Kochs was perhaps 
not altogether giving sufficient credit to the advantage which 
might be received from the thickness of the partition-walls be- 
tween the ovens, when double flues were used. He (Mr. O'Shea) 
did not think that the question of the storage of heat was of the 
first importance ; but he did think that double heating-flues pro- 
bably utilized the heat in each oven to better advantage. The 
thick partition-walls carried the weight of the superstructure, and 
thinner oven-walls could then be used, which allowed the heat to 
be conducted more quickly through the walls. The small experi- 
ence that he (Mr. O'Shea) had had in dealing with bye-product 
ovens had led him to notice how very large an amount was ex- 
pended annually in repairs ; and that, he thought, was largely 
due to the fact that the least fusible material was not employed 
in Great Britain for the erection of the oven-walls. He thought 
that more attention should be devoted to the selection of infusible 
bricks, because the intense heats that were obtained and the local 
heating that occurred suddenly, without proper attention on the 
part of those who had the care of the ovens, entailed a considerable 
amount of expense in the matter of repairs. Both the papers were 
valuable, because it was only by such papers that the members 
could obtain an idea of the construction of the ovens, and were 
enabled to compare the relative simplicity of different ovens. Bye^ 
product ovens were largely increasing both in number and in 
variety, and it was a matter of considerable difficulty to say which 
was the best. 

Mr. J. J. Prest (Horden collieries) said that the difference 
between Koppers ovens and other bye-product ovens appeared 
to be primarily in the adoption of vertical flues, and the manner 
in which the regenerative system had been scientifically worked 
out. The adoption of the regenerative coke-oven provided a 



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418 DISCUSSION — NOTES ON BYE-PKODUCT COKE-OVENS. 

large percentage . of consumable gases, and these could only be 
utilized efficiently in internal-combustion engines. Therefore, 
unless it was proposed to utilize the waste-gases in this 
manner, the regenerative system had better not be adopted. 
Many large installations of bye-product ovens and recovery- 
plants had been erected, within the last few years, at costs up 
to £100,000 or more ; but, whether the return on the large 
•capital-expenditures involved was satisfactory or otherwise, one 
could never definitely ascertain. Estimates of the probable 
amount of profit could be obtained in abundance: but figures 
giving the actual results were required. After careful considera- 
tion of the whole question, his firm had decided to erect an 
experimental plant of 70 beehive coke-ovens at one of their 
collieries, as it was considered that a larger commercial return 
would be obtained from them than from the erection of bye- 
product coke-ovens at this particular place, and under the special 
conditions prevailing. 

Dr. J. A. RoELOFSEN (Middlesbrough) said that Mr. Kochs 
stated that ** the construction of horizontal-flued ovens will not 
permit of more than three or four jets being employed at each 
end of the oven ; and it is quite evident that the walls cannot be 
so equally heated as the walls of vertical-flued ovens. . . ."* He 
might state that in some horizontal-flued ovens there were twelve 
burners for each individual oven ; and combustion in the horizon- 
tal-flued oven did not take place in a short space, as Mr. Kochs 
indicated, but. travelled as a luminous flame the entire length, 
•33 feet, of the oven-flue. This was effected by the proper 
regulation of the air-admission, and, if necessary, one could 
make some of the flame come back in the next flue ; consequently 
the heat along the length of the oven was uniform. Mr. Eochs 
stated that '* dark places " occuiTed,t he (Mr. Roelofsen) sup- 
posed, in the case of Koppers ovens. This was caused, as far as 
he knew, by some of the nozzles of the Koppers ovens closing 
and not being so accessible as was implied in Mr. Kochs' paper. 
At any rate, whatever the cause might be, it was easy to avoid 
dark spots in ovens when the gas-admission was under perfect con- 
trol by hand from the outside. Mr. Kochs said that " in horizontal- 
flued ovens, furthermore, the top flue is heated to a high degree, 

* Trans. Inst. M. K, 1907, vol. xxxiii., page 399. 
t Ibid., 1907, vol. xxxiii., pages 401 and 404. 



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DISCUSSION — NOTES ON BYE-PBODUCT CX)KE-OVENS. 419 

and it is generally admitted that this is a disadvantageous fea- 
ture, aa the great heat has the effect of decomposing the gases 
of distillation. . . ."* This latter was quite true, but he main- 
tained that the horizontal-flued oven was particularly suitable for 
avoiding the creation of excessive heat at the top of the oven, 
inasmuch as heating took place in horizontal strata so to speak, 
and, by regulating the gas-admission in each horizontal flue, 
ihat particular stratum of the oven could be kept cool or hot as 
was desired. For practical purposes it was, as everyone ad- 
mitted, necessary and desirable that all parts of the oven should 
be uniformly heated, and that no part should be overheated; 
and this was done every day in horizontal-flued ovens. Mr. 
Kochs stated that in the Koppers oven the top portion was 
kept from 400° to 500° Fahr. cooler than the bottom portion ; t 
and, if this were so, he failed to see how that could be called 
uniform heating. It was also stated that the division-wall was 
absolutely necessary in horizontal-flued ovens, otherwise the 
ovens of that sort would not be strong; but this was not so. 
He had a battery of 100 Huessener ovens which had been at 
work on the Continent for 20 years, and were at work at the 
present day. They had never had division-walls, and yet during 
that time they had been making coke and had given such good 
results that the expenditure on repairs during the last 10 years of 
iheir life had only been between Jd. and id. per ton of coke made. 
This showed that it was not absolutely necessary to use division- 
walls in horizontal-flued ovens. After making many experiments 
over many years, the Huessener oven had, however, finally adopted 
the division- wall, although, as Mr. Kochs had correctly remarked, 
it extended along the whole length of the oven-battery and made 
the structure more expensive. For this reason it naturally handi- 
capped them in competing with the builders of coke-ovens with- 
out a division-wall. The Huessener oven would discard the middle 
wall, which caused greater capital outlay and more ground-space 
to be covered, if it were not believed that there were substantial 
advantages to be gained from its adoption. It had been stated 
that the value of division-walls had been under-estimated : he 
agreed that it doubled the number of flues round the ovens. It 
was well known that, during the last stages of coking, the charges 
in the oven did not require such an amount of gas as a fresh 

• Tram, Inst, M, E,, 1907, vol. xxxiii, page 399. 

t Ih%d,y 1907, vol. xxxiii., page 400. 



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420 DISCUSSION — NOTES ON BYE-PRODUCT COKE-OVENS. 

charge ; and if there were no division-wall, it was not possible i\> 
check the heat on the oven, which naturally became hotter 
because it was older in coking time. Furthermore, as had 
already been pointed out, the division-wall carried the super- 
structure of the oven, which was of the greatest importance. 
It relieved the oven-walls of the heavy weight on the top of the 
oven and enabled the walls to be made thinner. Without going 
any further into a theoretical discussion, it was desirable to get 
practical figures of everyday work. The. figures for a battery 
of 60 Huessener ovens, now in their seventh year of work 
without interruption in the county of Durham, working with 
ordinary Durham coking coal, containing about 30 per cent, 
of volatile matter, were as follows: The cost of repairs to these 
60 ovens was only about Jd. per ton of coke, and during the 6^ 
years that they had been at work, only six ovens had been re- 
lined. The ovens were built of British material ; and, al- 
though the oven was of German origin, it had not been found 
necessary to go abroad for refractory fire-bricks. There was 
no lack of good fire-resisting fire-clay in this country ; and the 
only difficulty was to get fire-brick-makers to work accurately 
to dimensions, and to produce bricks of perfect shape. There 
was no need to go to Belgium or Germany for material, and if 
brick-makers would study the nature of their fire-clay, and make 
proper allowances for shrinkage, they could produce a brick of 
good shape and perfect dimensions. Mr. Eochs stated that, in 
Westphalia, the Koppers oven made 5*2 tons of coke per oven 
per day, or 1,800 tons of large coke from 50 ovens per week. 
He thought that this result was obtained from Westphalian coal 
containing about 20 per cent, of volatile matter ; could Mr. Kochs 
give the production of coke from coal containing 30 per cent, 
of volatile matter, as in the case of Durham coal, or 32 per cent, 
as in the case of South Yorkshire coal ? It would also be interest- 
ing to know the cost of repairs, during the four years that Koppers 
ovens had been on the market. 

Mr. Emerson Bainbridge said that Mr. Prestos remarks were 
all the more interesting, as that gentleman was never behind 
in finding out the most modem improvements in mining engin- 
eering, and therefore they were to be regarded with all the more 
weight. His own experience, however, had been that the 



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DISCUSSION NOTES ON BYE-PRODUCT COKE-OVENS. 421 

proprietors of new plants were only too anxious to point out 
the advantages of such plants, and they would no doubt take 
the opportunity of doing so. There had been marvellous pro- 
gress in Germany in the utilization of the waste-gases from 
coke-ovens, and it justified one in expecting that in a few years 
there would be many collieries working their entire plant, 
without steam, by gases produced from bye-product ovens. He 
was afraid that the multiplication of bye-product ovens might 
lead to such a diminution of the value of the materials produced 
as to make the advantage rather less important than at first it 
appeared to be ; but, as the demand seemed to continue, the 
values might be maintained. 

Mr. R. SuTCLiFFE (Bamsley) said that for several years he 
had been using compressed-air plant, and he felt that the present 
method was a wasteful one. He believed that it was partly 
due to the piston of the steam-cylinder travelling at the same 
speed as the piston of the air-compressing cylinder; and, in 
order to get a high efficiency from the steam-cylinder, the piston 
of the air-cylinder was overrun. He had had some experience 
in the use of gas-engines, and, after having used steam-engines 
for many years, he had come to the conclusion that the former 
was the most economical when used for power-purposes in con- 
nection with gas produced at a colliery. 

Mr. Isaac Hodges said that a life for bye-product ovens of 
6i years, with negligible repairs, was almost unprecedented in 
his own knowledge, and must be largely due to the state of 
dryness in which the coal went into the ovens. 

Dr. J. A. RoELOFSEN said that washed coal was used, contain- 
ing 12 per cent, of water. 

Mr. Hodges said that he had never heard of a bye-product 
coke-oven standing for 3 years, and 6 years was unprecedented. 
He had found from experiments that the lime in the water 
acted as a flux on the fire-bricks, and produced extensive honey- 
combing. Dr. Roelofsen must have used exceedingly pure water 
at the ovens under his charge, or they must have been built with 
exceptionally good bricks : he thought that he had used the 
same bricks, and therefore it was difficult to correlate the facts. 
After 10 years' experience of bye-product ovens, he had found 



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422 DISCUSSION — ^NOTES ON BYE-PRODUCT COKE-OVENS. 

that the bye-products of a comparatively new oven were much 
larger than those obtained from an oven in a poor state of 
repair. Horizontal flues, which were so much -a feature of the 
earlier bye-product ovens, had almost entirely disappeared; 
the chief reason had not been mentioned by Mr. Kochs, namely, 
the effect of the wind-pressure on the horizontal flues, causing^ 
that part of the oven to be rapidly cooled ; and for that reason 
he had changed to vertical-flued ovens. The flues of the ovens- 
under his charge had no middle wall; he believed that the 
superstructure was too heavy a burden for the flues to carry in 
normal times, especially after being slightly weakened. However, 
he agreed that the middle wall, if not absolutely necessary, was a 
great convenience in the case of repairs. The ideal oven was one 
which would not fail because it had a very heavy superstructure 
to carry ; the fabric should remain intact, so that it could be 
relined at leisure, making the cessation of coking a limited 
matter, and reducing at the same time the cost of repairs. 

Mr. J. Kenneth Guthrie (Leeds) wrote that the Otto Com« 
pany, in Germany, introduced the regenerative principle about 
20 years ago, and for many years enjoyed almost a monopoly witk 
their regenerative coke-ovens. About 1895, however, coke-ovens 
of the waste-heat type came to the front as rivals ; and, realizing 
that this type of oven had some striking advantages, more espe- 
cially in simplicity of construction and greater provision of steam 
for colliery-purposes, the arrangement of heating from below 
the oven as introduced by Mr. Hilgenstock had been applied 
mainly in waste-heat ovens, but, of course, they were equally fitted 
for regenerative purposes. The Otto Company had erected many 
ovens of this type in Germany, etc. ; but in Great Britain there 
was a strong preference for the waste-heat type, owing, no doubt, 
to the fact that gas-engines did not enjoy the same popularity in 
this country as on the Continent. 

Mr. H. W. Seymour (Leeds) wrote that Mr. Kochs' paper was 
very interesting, in so far as it showed the most recent construc- 
tion of the Koppers oven. The comparison drawn, however, be- 
tween that oven and horizontal-flued ovens was naturally to the 
disadvantage of the latter, and faults were shown that were non- 
existent in any modem system of horizontal-flued ovens. So 
far as Great Britain was concerned, the latter system waa 



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DISCUSSION — NOTES ON BYE-PRODUCT COKE-OVENS. 42^ 

meeting with increasing' favour, and as many, if not more, were 
being erected as those of the vertical-flued type. It was pro- 
bably on account of the vertical-flued system being built wholly 
by German companies that they had found such favour in Ger- 
many. Mr. Eochs had been misinformed as to the largest number 
of jets possible in a horizontal-flued oven being three or four 
on each side : * it was quite possible to use as many as eight or 
nine jets on each side. The same effect, however, as a large 
number of jets, was obtained in a simpler way, by admitting the 
air for combustion at various points. In practice, it was found 
that as regular a heat was obtainable as with the vertical-flued 
system. Intense overheating of the top-flue was not a feature 
of horizontal-flued ovens ; in most types the top part of the oven 
could be controlled from comparative coldness to an intense heat, 
without affecting the heat of the lower part of the oven : this 
feature not bein^ possible with the Koppers type of oven. 
Judging^ from the number of inventions intended to obviate this 
defect, the excessive heating of the top part of an oven appeared 
to have been a difficulty met with to an even greater extent in 
vertical-flued than in horizontal-flued ovens. 

The experience of many builders proved that the solid central 
partition was a most valuable and indispensable feature, as it 
facilitated repairs, two ovens only being partly affected instead 
of four ; and it considerably reduced the period of coking. In 
the case of two plants working side by side, one with and the 
other without a central wall, the flues of the latter appearing to 
be hotter than the central-wall plant, the production was only 
22 tons of coke per week as against 26 tons. The increase in 
the length of a plant built with central partition-walls would 
certainly not exceed 20 to 26 per cent., and the heat-radiation, 
especially with ovens surrounded by air-flues, would be even less 
than with the single-flued vertical type. It was usually 
found in the course of time that the tops of single-flued ovens 
sank to a greater extent than in the case where the great weight 
of the superstructure was supported independently of the highly 
heated thin oven-walls ; it was to be noted also that a thinner 
oven-wall could be used where this weight was supported by a 
solid central wall. 

It might be thought from Mr. Kochs' remarks that no surplus 

* Traiu. Inst. if. E., 1907, vol. xxxiii., page 399. 



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424 DISCUSSION — NOTES ON BYE-PRODUCT COKE-OVENS. 

^s was available in the case of a non-regenerative oven; but 
in the case of Yorkshire coal, at least 33 per cent, of the gas was 
available, phis all the steam required for working the plant. It 
was a question, therefore, whether it was worth the capital-charge 
and complication to work a regenerator for a gain of 5 or 10 
per cent., especially where steam had to be made for working 
the plant. This point was well exemplified in the case of one 
regenerative plant, where the coke-oven boilers were hand-fired 
with coal. He (Mr. Seymour) acknowledged the theoretical 
value of many of the ingenious contrivances explained by Mr. 
Kochs, but so far as practical working was concerned he would 
like comparisons to be made with other than German coal. The 
English equivalent was apparently not greater than 20 to 25 
tons of coke per week; and both in quality and quantity of 
products this could be easily equalled by any modem type of 
horizontal-fiued coke-oven at a lower capital-outlay than with a 
plant such as the one in question. Further, the ease of inspec- 
tion and adjustment at every stage of the working in a horizon- 
tal-fiued oven proved of paramount importance in practice; 
and, from the results obtained at many plants in this country, 
it did not appear as if they were gained at the expense of the 
oven — considered as a producer of saleable coke and bye-pro- 
ducts. The working results of the plant described by Mr. Eochs 
did not warrant, in his opinion, such claims of superlative 
excellence over and above other systems having the same end 
in view. 

Mr. A. Victor Kochs, replying to the discussion, wrote that 
he was obliged to disagree with the view expressed by Mr. O'Shea 
that the provision of a division-wall enabled the heat in each oven 
to be utilized to better advantage, as it was an incontrovertible 
fact that heat was lost through radiation by greatly increasing 
the length of the battery, which could not possibly be avoided if 
a central wall and double fines were adopted. Whereas in 
single-flued vertical ovens, as pointed out in his paper, any cool- 
ing effect, which a freshly charged oven might have on its neigh- 
bour, would simply be an exchange of heat and would have not 
the slightest influence on the ultimate result. Mr. O'Shea further 
stated that the dividing wall served to support the superstruc- 
ture, and the walls of the oven could therefore be made thinner. 



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DISCUSSION-^NOTES ON BYE-PRODTJCT COKE-OVENS. 425 

To a certain degree this waa correct^ but there was a limit to 
the thinness of the oven-walls; and, as a matter of fact, the 
walls of vertical-flued ovens were no thicker than those of hori- 
2ontal-flued ovens arranged with a dividing wall. A large 
number of Koppers ovens had been built with side-walls, not 
exceeding 3 inches thick. If the walls were made thinner, 
leakage of the gases of distillation into the heating-flues would 
be very considerable, especially after the ovens had been work- 
ing for some time. The strength of the walls of Koppers ovens 
lay mainly in the flue-partitions, 5 to 6 inches thick, and only 
to a comparatively small extent in the side-walls, 3 to 3f inches 
thick. The total weight of the superstructure, including the 
gas-collecting equipment and three loaded corves, carried by 
each single wall, amounted as a maximum in the Koppers oven 
to no more than 32 tons, and as the sectional area of the walls 
at the weakest point was 35 square feet, the load per square 
foot was rather less than 1 ton. Fire-bricks, such as were em- 
ployed in Koppers ovens, had a crushing strength equal to 150 
to 200 tons per square foot, and an easy calculation would show 
that the walls were 150 to 200 times as safe at the weakest 
part. This was, of course, when the ovens were cold, but it 
was, nevertheless, abundantly clear that the factor of safety 
would be more than ample when the ovens were in a heated 
condition. The sectional area on a line drawn horizontally 
through the heating-flues was 52 square feet, and this surface 
would support a load of several thousand tons ; and it was quite 
obvious that there was no likelihood of such a wall giving way 
through the comparatively light superincumbent weight. 
Further, the single vertical-flued wall of the Koppers oven was 
even stronger than that of a horizontal-flued oven with two sets 
of flues and a dividing wall, 14 inches thick. The whole of 
the weight of the superstructure in a horizontal-flued oven rested 
on the dividing wall, and the horizontal sectional area of this wall 
was no more than 40 square feet as compared with 52 square 
feet in the Koppers oven. In addition, the weight of the super- 
structure of a horizontal-flued oven was very considerably more 
than that of a single vertical-flued oven, which was due, of 
course, to the ovens being further apart. The area of the wall 
being less and the weight to be carried being greater, it neces- 
sarily followed that the construction was considerably weaker 

TOL. XXXI1I.-1906.1907. ^^ 



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426 DISCUSSION — ^NOTES ON BYE-PRODUCT COKE-OVENS. 

than that of the Koppers oven. It was, therefore, quite fallacious 
to claim that the dividing wall was an advantage as regarded 
strength. 

The fire-bricks employed in the construction of Koppers ovens 
were made of a special composition which had been found, from 
experience, to be most suitable for the purpose. This material 
could be obtained in England, and the only trouble experienced 
was in getting the bricks made to the exact sizes and shapes 
required. Brickmakers were, however, now taking much 
greater care in the manufacture of the bricks, with the result 
that complaints aa to size had seldom to be made. 

The supposition expressed by Mr. Prest that the difEerence 
between the Koppers oven and other systems was primarily in 
the regenerative principle was incorrect ; and, as there appeared 
to be a general misapprehension in this regard, he (Mr. Kochs) 
would here emphasize the fact that the main advantages of the 
Koppers oven were the same, whether the oven was designed to 
work with or without regenerators. The special feature of the 
Koppers oven was the uniform heating of the walls, combined 
with easy accessibility of all flues for regulation and inspection, 
which was attained to a remarkable degree of perfection. The 
regenerators were only necessary adjuncts, when the surplus heat 
in the coal was required to be produced wholly in the form of a 
combustible gas for firing existing boilers situated at a point re- 
mote from the battery of ovens, or where power was required to be 
generated by means of gas-engines, in which latter case about 
3 times the power would be derived that could be obtained 
by raising steam with the gases, or that could be generated by 
the waste-heat from non-regenerator ovens. The information 
as to the commercial results to be obtained from a bye-product 
oven-installation was rather difficult to supply, as there were 
so many factors that affected the economy and working of the 
ovens, which varied in different parts of the country. The prin- 
cipal factor was the quality of the coal together with the amount 
of residuals which it contained, whilst other factors were the 
value of the coke produced, the length of time required for carboni- 
zation, the percentage of alkaline salts contained in the coal 
(which had the effect of corroding the oven-walls and rendered 
repairs frequently necessary), etc. The size of the plant had also 
much to do with the return, as the first cost and the labour-cost 



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DISCUSSION — NOTES ON BYE-PRODUCT COKE-OVENS. 427 

did not increase proportionately with the capacity. Any figures 
therefore which might be given would probably be misleading; 
but, generally speaking, it could safely be stated that a mode- 
rate-sized plant of 60 ovens costing, say, £60,000, would yield 
a return of from 30 to 40 per cent., after making full allowance 
for repairs and redemption of capital. 

Dr. Roelofsen had pointed out an error in his paper, wherein 
he stated that only three or four heating-jets were employed at 
each end of a horizontal-flued oven. This was an inadvertence, 
and he should have stated that there were three or four jets at 
each end of each set of heating-flues. He (Mr. Kochs) noted that 
the Huessener oven was heated at six points at each end of the 
oven, that was twelve points altogether; and, as it was more 
particularly in respect to the distribution of the heating that 
the Koppers oven was distinguished from other systems, he 
would draw particular attention to the fact that each Koppers 
oven was heated by sixty to seventy gas-jets. It would there- 
fore be apparent that there was far more likelihood of uniform 
heating being attained with a large number of jets distributed 
along the length of the oven, than by comparatively few jets 
at the ends only. As regards the " dark places " referred to 
in his paper, he must express surprise that Dr. Roelofsen should 
take exception to this term, as it was a technical expression 
universally employed to indicate the comparative intensity of 
the heating of the walls. In horizontal-flued ovens, there were 
only twelve really ** bright places," that was at each point where 
the gas was admitted ; and no one could deny that it was theoreti- 
cally and practically impossible for a flame, 33 feet long, or even 
half that length, to be as hot at the end after giving up its heat 
to the charge of coal, as it was at the point of combustion. This 
was the reason why the building of horizontal-flued ovens had 
been abandoned in Germany, and in his (Mr. Kochs') opinion 
admitted of no argument. Dr. Roelofsen also referred to the 
statement that there was a difference of 400° to 500° Fahr. be- 
tween the temperatures of the top and the bottom of the oven, 
and he was at a loss to see how that could be called equal heat- 
ing. Dr. Roelofsen must be well aware that uniform heating 
was required along the length of the oven, and not so much in 
the height ; that was, that the greatest heat should be applied 
opposite the bottom of the charge, lessening towards the top, but 



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428 DISCUSSION — NOTES ON BYE-PRODUCT COKE-OVENS. 

equally along the length of the oven, so that the charge of coal 
would be subjected to exactly the same temperature throughout 
its length, and so that the top part of the charge would not 
be too intensely heated. 

In making the statement that there was on the Continent a 
battery of 100 Huessener ovens arranged without division-walls, 
which had been at work for twenty years and had cost very little 
for repairs, Dr. Boelofsen should have pointed out that the side- 
walls were made correspondingly thick to compensate for the 
absence of the division-walls ; and the effect of these thick walls 
was the prolongation of the period of coking, as the heat could 
only pass through very slowly. These ovens, he understood, 
required 48 hours to bum ofE. It was easily understood, there- 
fore, why the single-flued wall was finally discarded in the Hues- 
sener oven. At any rate, it was quite clear that, if a single 
horizontal-flued wall would stand the length of time stated by 
Dr. Roelofsen, a single vertical-flued wall, being a much supe- 
rior and stronger construction, would last very considerably 
longer. The figures given by Dr. Roelofsen as to the cost 
of repairs at the Huessener plant in Germany, and also those 
given of the plant in Durham, must have been miscalculated, 
as he had been informed by a former manager of the first-named 
plant, who was now in charge of a large installation of Koppers 
ovens, that the walls of the ovens required renewal, every two 
to three years, notwithstanding that the ovens were worked at 
a comparatively low temperature: the coking period being, as 
already stated, 48 hours. In regard to the Huessener plant in 
Durham, Mr. C. Lowthian Bell* had stated that the cost of re- 
pairs taken over 12 months, after the ovens had been working 
three years, amounted to l'60d. per ton of coke. It was diflGlcult 
to reconcile this figure with that given by Dr. Roelofsen, namely, 
Jd. per ton of coke, after the plant had been working for seven 
years. 

Dr. Roelofsen was correct in stating that, during the last 
stages of coking, the charges of the oven did not require the same 
amount of gas as in the earlier period of coking ; but, after men- 
tioning that without a division-wall it was not possible to check 
the heating, he should have added that this was unnecessary and 

* "The Manufactiire of Coke in the Huessener Oven at the Clarence Iron- 
works, and its Value in the Blastf umaces, " by Mr. C. Lowthian Bell, The J(mmal 
of The Iron and Steel InatittUe, 1904, vol. Ixv., page 188. 



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DISCUSSION — ^NOTES ON BYE-PBODtTCT OOKE-OVENS. 429 

waa never done with single-flued ovens, being only rendered 
necessary by the provision of a division-wall. It never 
happened that two adjoining ovens were charged at the same 
time, and consequently there would always be a more or less 
considerable difference in the coking stages of any two ovens. 
As a result, when one oven was ready, its neighbour would re- 
quire heating for a further period of time. The heat produced 
in the flues automatically passed to the charge, which was in- 
completely carbonized, whilst the oven which contained the com- 
pleted charge would take only a comparatively small portion of 
the heat. It would be obvious that this would not be possible 
if a division-wall were placed between the ovens, and towards the 
later period of coking the heat on such ovens must be checked, 
otherwise overheating, with possibly disastrous consequences, 
would occur. The single-flued walls of the Koppers oven, on 
the other hand, could not only be maintained at the same high 
temperature throughout the coking period', but could be forced 
in the second half of the coking period without fear of overheat- 
ing, and it was for this reason that a greater output of coke was 
obtainable from the Koppers oven than from any other system 
working under equal conditions. 

As mentioned in his (Mr. Kochs') paper, the output of coke 
was dependent upon the character of the coal, the size of the 
ovens and the working conditions. The amount of moisture in 
the coal also affected the coking period, whilst the time of coking 
was extended if the coal were charged into the oven in the 
form of a compressed cake. Nearly all the Koppers ovens 
erected in England were from 22 to 24 inches wide, and with 
one exception the coal was compressed in every plant. The 
output of coke from ovens working with compressed coal was 
28 tons per week from Durham coal, and 26 tons per week from 
South Yorkshire coal, whilst the output from ovens working 
with uncompressed coal was 35 tons per week. In the latter 
case, however, the coal contained only 20 per cent, of volatile 
matter. A reduction in the width of the oven would enable the 
output to be considerably increased ; and, in comparing the yields 
of several different types of ovens, the width should be taken 
into account. The reduction in the width had the disadvan- 
tage, of course, of producing short pieces of coke. 

He (Mr. Kochs) had been asked to state the cost of repairs 



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480 DISCUSSION — NOTES ON BYE-PEODUCT COKE-OVENS. 

of Eoppers ovens, and ag^in in this regard he mu&t say that the 
cost of repairs depended greatly upon the working conditions, 
which varied considerably at difierent plants. The great bulk 
of Koppers ovens which had been erected during the last four 
years, that was, since the oven, was introduced, had not cost 
Id. in repairs. The heating of the ovens, as would have been 
seen, was so uniform that the oven-walls were subjected to a 
much smaller variation in temperature than in any other system, 
and the wear-and-tear was therefore correspondingly less. In 
cases where the coal was charged into the ovens in a very wet 
state, or where the coal (or the water in the coal) contained alka- 
line salts, the wall-bricks sufEered severely ; and any oven work- 
ing under such conditions would require frequent repairs, espe- 
cially those systems which were not uniformly heated. He 
could safely state that the cost of repairs of a battery of Koppers 
ovens, working under normal conditions, would be lower than 
that of other systems, and further, that no serious repairs would 
be necessary during the first four or five years. After this 
period of time, it would probably be necessary to renew the lower 
courses of bricks in the oven-walls. 

The Chairman (Mr. J. C. Cadman) moved a vote of thanks 
to Mr. A. V. Kochs for his interesting paper. He might mention 
that in some districts, particularly in North Staffordshire, slack- 
coal, which was formerly almost given away, was now washed and 
made into a valuable coke, through the introduction of bye-pro- 
duct coke-ovens. 

Mr. Isaac Hodges seconded the vote of thanks, which was 
heartily carried. 



The Rev. G. M. Capell read the following paper on " The 
Application of Duplicate Fans to Mines " : — 



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APPLICATION OF DUPLICATE FANS TO MINES. 481 



THE APPLICATION OF DUPLICATE FANS TO MINES. 



By the Rbv. G. M. CAPELL. 



The general idea has hitherto prevailed that little or any 
advantage could be gained by using two fans, on one upcast- 
shaft, as compared with running one of them singly at the same 
speed. There are records in the Transactions* which appear to 
confirm this idea, that whether one or two fans are run at an 
equal speed, the result will practically be the same ; but in cdl 
those past experiences the fans were not placed on the mines with 
a view to their working together. On thinking over the question, 
the writer came to the conclusion that the disposing of two fans 
on a mine, either a single or a double inlet, in such relative posi- 
tions to each other that the passing of the air would correspond 
to the action of a double-inlet fan, was possible, and would pro- 
duce the results of a double-inlet fan with other advantages. 

The positions of the fans, Ai and Ag could be arranged so as 
to resemble the action of a double-inlet fan, by using the parting 
of the air-drifts between the inlets (figs. 1 and 2, plate xvii.). 
Another condition must be considered, namely, that in double- 
inlet fans, Ai and Ag (fig 3), with a central dividing-plate, each 
fan is practically a separate machine, so far as each inlet is con- 
cerned. There is, however, a great difference between a double- 
inlet fan and two separated fans, namely, that the double-inlet 
fan, working in a single casing, has a constant condition of water- 
gauge in that casing; whereas two fans, working in duplicate, 
might have a variation of the water-gauges in the casing, arising 
from small difference of speed, or in those variations which affect 
air-currents in coming to the inlets -of a fan. This is remedied 
by a regulating passage, with a valve connecting the two fan- 
cases in the new arrangement. With this arrangement for balanc- 
ing the case-pressures, the two fans can be relied on to act as if 

* *' A Duplex Arrangement of Centrifugal Ventilating Machines," by Mr. 
W. Cochrane, IVana, Inai, M. E., 1891, vol. ii., page 483. 



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482 APPLICATION OF DUPLICATE FANS TO HINES. 

they were running in one casing. Tte equalizing or regulating 
passage, F, is shown with its valve, g, placed between the two 
fans (figs. 1, 2 and 3, plate xvii.).* 

In working a fan by tri-phase current, now so much in use, a 
difficulty presents itself, namely, the great loss of power at week- 
ends and other off-days, by being unable to regulate in a simple 
manner the speed of the fan and the consumption of current. In 
the application of two single-inlet fans, say, 16 feet in diameter^ 
to a mine, at 220 revolutions per minute, the two fans would 
each produce 260,000 cubic feet of air per minute at 6^ inches of 
water-gauge in the inlet-passage; and this would unite in a 
common water-gauge, beyond the division between the inlets, 
that is, in the main drift, D. A model of the arrangement shows 
very clearly, when one motor-driven fan is stopped and the auto- 
matic drift-door is closed, by the minus or suction water-gauge of 
the working-fan, still running at the same speed, and using the 
same power as when creating 6^ inches of water-gauge, that the 
single fan will pass 66 per cent, of the volume of air produced bj^ 
the two fans, working together at the same speed, at 2*8 inches of 
water-gauge. Consequently, the speed of a tri-phase motor need 
never be changed in these duplicate fans, and the cost of working 
the fans can, in a minute, be reduced to half, or even less than 
half, at pleasure, while 66 per cent, of the full daily circulation 
of air is secured in the mine. The difficulty of reducing the 
speeds of tri-phase motors first turned the attention of the writer 
to this new application of duplicate fans. 

It may be of interest to state that the actual cost of the two 
duplicate fans is very little more than that of a single fan to do 
the same maximum work. It will doubtless be seen that great 
advantages will result from applyinor this system especially to 
new mines, where one fan will probably be sufficient to ventilate 
the mine for, say, 10 years ; and the other fan can be added, as the 
water-gauge of the mine, the length of the air-ways and the 
rubbing-surface increase. The two fans can then be worked 
together in unison, and prodtice the higher water-gauge required, 
with a larger volume than that produced by the single fan. 

The reason why one fan running alone at the same speed as 
the two fans produces up to 75 per cent, of the volume produced 

* British patent, April 28th, 1906, No. 9,952 ; and United States patent^ 
November 6th, 1906. 



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'■e^Ajix^.i, orJ/inui-g I^ n^imrrs 



VolJLXXULTjjweWIL 



,^Oor^>' 19062907 

To illustrate^ the^Sei^, CKCapeUs Paper onfTTbeAppbcatioTi 



ofDupUcaie^Fans to Mutes '! 



FiQ. 1.— Side Elevation of Sinqle-inlet Fan. 



BEFERJENOE. 
DIRECTION OP AIR-CURRENT« - 




FiQ. 2.— Plan of Arrangement of Duplicate Fans 
^^,,___, with Single-inlets 



31r: "^m^ 



Fig. 3.— Plan of Arrangement of Duplicate Fans 
^i^^S^^^jj^cv^ with Double-inlets. 




Soale^je^Feet^toJ Inch, 

AnSTUnd & CompYL'* Newcasile upanTjm* 



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DISCUSSION — ^APPLICATION OF DUPLICATE FANS TO MINES. 48S 

by the two fans, on this duplicate system, is very simple. If the 
volume, say, 400,000 cubic feet per minute at 6 inches of water- 
gauge, is produced by two fans at equal speeds : then, if 300,000 
cubic feet per minute be passed, the water-gauge, due to 300,000 
cubic feet under the same mine-conditions, will be reduced from 
6 inches to 3'375 inches, and the horsepower in the air will be 
163-6. When one fan is producing half of 400,000 cubic feet at 
6 inches of water-gauge, the horsepower in the air is 189, 
leaving a wide margin for loss of useful effect due to the large 
volume per revolution passing through the fan under the lower 
water-gauge, because the water-gauge produced by the fan at its 
normal speed is transformed so largely into volume : a fact well 
known to engineers who have tested fans on a mine, under varying 
water-gauge conditions. 

Duplicate fans, for the largest volumes and high water-gauges, 
are now in construction ; and, when they are running, the form- 
ulas relating to their work will be compiled so as to enable them 
to be easily adapted to the varying conditions of mines. 



The Chairman (Mr. C. C. Leach) asked what results would be 
obtained by the two fans, where one fan delivered the air through 
the other. 

The Eev. G. M. Capell said that, in such a case, the same 
efEect was obtained as in a series pump. He had calculated the 
anticipated results of the two fans long before they were made : 
he had then worked the details into a practical form, and it 
was possible to get almost any desired result at varying water- 
gauges. The duplicate fans as shown in figs. 1 and 2 (plate 
xvii.) had not yet been tested on a mine; but an electrically- 
driven plant was in course of erection. 

Mr. Robert Clive (Doncaster) asked what would be the effect 
if one fan was run at a higher speed than the other. 

The Rev. G. M. Capell said that the fans woul