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Full text of "Annual report of the City Engineer"

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City Document. — No, 19. 



CITY OF BOSTON 




ANNUAL REPORT 



CITY ENGINEER, 



FOB THE TEAR 



1874, 



CITY OF BOSTON. 



Office of City Engineer, City Hall, 

Boston, Jan. 26, 1875. 

To the Honorable City Council : — 

In accordance ^\ath the requirements of the sixth section 
of the ordinance relating to the Engineer's Department, the 
following report of the expenses and operations of the de- 
partment for the year 1874 is respectfully submitted. 

Statement of engineering expenses from January 1st, 1874, 
to January 1st, 1875 : — 
Amount expended from department 

appropriation for 1873-74 . $6,831 94 
Amount expended from department 

appropriation for 1874-75 . 18,934 31 



Total expended from department ap- 
propriations 125,766 25 

Amount expended from special and 

other appropriations ..... 9,248 06 



Total $35,014 31 

Condition of department appropriation : — 
Amount of appropriation for financial year 

1874-5 $30,881 00 

Amount expended to January 1st, 1875 . . 18,934 31 



Unexpended balance January 1st, 1875 . . $11,946 69 



4 City Document. — No. 19. 

CLASSIFICATION OF EXPENSES FOR 
ENGINEERING. 

City Engineer's Office. 

Salaries of City Engineer, assistants, * 

draughtsmen, rodmen, etc. 
Instruments and repairs of same 
Drawing paper and materials 
Stationery, printing stock, etc. 
Reference books, maps and frames 
Printing and advertising 
Travelling expenses, horse-keeping, etc. 
Incidental expenses 
Committee expenses 

Total 



$22,770 00 


694 


90 


571 


70 


333 


56 


84 


50 


49 


98 


912 


98 


340 


63 


8 


00 


$25,766 25 



Temporary branch offices at West Roxbury and Brighton. 
Expenses charged to special appropriation, " Water Works, 
Wards 13 to 16, and extension to Wards 17 and 19." 



West Roxbury Office. 

Salaries of assistants, rodmen, etc. 

Furniture ....... 

Surveying and drawing instruments 

Drawing paper and materials 

Stationery and note books .... 

Travelling expenses ..... 

Gas fixtures . . . . . . 

Fuel 

Incidental expenses, including care of office and 
small supplies ...... 

Total 



$752 50 


250 


00 


204 


75 


48 


13 


36 


23 


30 


30 


18 


00 


20 


70 


38 


28 



$1,398 89 



Keport of City Engineee. 



Brighton Office 



Salaries of assistants, rodmeii, etc. 


$764 50 


Furniture ....... 


250 00 


Surveying and drawing instruments 


42 75 


Drawing paper and materials 


78 80 


Stationery and note-books . . , . 


36 23 


Travelling exj)enses ..... 


11 00 


Gas Fixtures ...... 


40 24 


Fuel 


20 70 


Incidental expenses, including care of office and 




small supplies . . . . 


28 18 


Total 


$1,272 40 



Parker Hill Eeservoir.* 
Pay-roll and incidentals .... $1,866 25 

Eastern Avenue and Bridge.* 
Pay-roll and incidentals . . . .' $1,89686 

Broadway Bridge Foundations.* 

Pay-roll and incidentals . . . . $1,10606 

* 

Northampton-street District.* 
Pay-roll and incidentals .... $896 60 

West Boston and Canal Bridges. 

Pay-roll and incidentals (one half of this amount was paid 
by the City of Cambridge) . . . $811 00 

The number of persons employed and paid from the de- 
partment appropriation, was, on the first of January, 1874 
(including the City Engineer), 19. The present number is 

* Special appropriations. 



6 City Document. — No. 19. 

25. Average number during the year, 23. Number at 
present employed in Brighton office, five. In West Rox- 
bury office, four. 

The engineering force engaged upon the work pertaining 
to "additional supply," although under the immediate direc- 
tion of the City Engineer, is distinct from the force of this 
department, and is employed and paid by the Water Board. 

The large amount and important character of the work 
performed by this department, during the past year, has 
necessitated the employment of a considerable number of 
temporary assistants, and some additions have been made to 
the permanent force. The system of having all work of 
any magnitude done under the supervision of competent in- 
spectors has relieved the assistants from that constant atten- 
tion to the practical details of construction, which formerly 
occupied so much of their time. The department force has 
by this means been able to accomplish much more work, and 
the results obtained have been more satisfactory. 

The operations of the department for the past year, to- 
gether with such general information relating to the various 
works and structures finished and in progress, as is thought 
to be of interest, are given in the following statement : — 

WATER WORKS. 

Lake OocJiituate. — At the beginning of the year the 
water in Lake Cochituate stood 9 feet 8| inches above the 
bottom of the conduit; January 29th it had risen to 12 
feet 61 inches and from that date it was allowed to waste 
over the dam, until Fel^ruary 14tli, when it stood at 12 feet 
Z\ inches. 

During March, April, May and June, it was kept at very 
near high-water mark. 

Waste has been allowed during the following intervals : — 
from January 29th to February 14th, from February 2 2d to 



Report of City Engineer. 7 

March 3d, from April 23d to May 6th, from May 16th to 
May 28th, and from June 6th to Jmic 10th. The total waste 
over the dam, for the year, has been 1,145,852,000 gallons, 
equal to an average daily supply of 3,139,320 gallons. 

June 22d the water stood at high-water mark, and since 
that time it has gradually fallen, standing September 1st, 10 
feet, 2| inches ; November 1st, 6 feet, 4\ inches, and on 
December 31st, 2 feet, 2^ inches above the bottom of the 
conduit. 

In September, a severe drought began, which has lasted till 
the present time. Early in Noveml^er it became evident 
that it would soon be necessary to resort to pumping water 
irom the lake, in order to keep up a sufficient supply to the 
conduit, and on the 11th of that month the Water Board 
ordered the pumps and engines to be put in readiness for oper- 
ation at as early a day as practical^le. At this time and 
during November and a portion of December, the Mystic 
works were supplying the city proper with from two to two 
and a half million gallons per day, which, as the consump- 
tion for those mouths was much below the average, enabled 
the conduit, though running but partially full, to slowly in- 
crease the depth of water in Chestnut Hill reservoir. 

December 3d, the water was drawn from the conduit to 
allow stop-planks to be put in at the gate-house. On the 
evening of that day, the pumps were started, and have con- 
tinued in constant opei'^ation, — with short stoppages for 
repair, — till the present time ( January 26 ) , and have 
lowered the lake to 6| inches below the bottom of the con- 
duit. 

Conduit. — A thorough examination of the interior of the 
conduit was made December 3d, by Mr. "VVightman and 
Mr. Cunningham, the latter passing through from the lake to 
Charles river, and the former from the river to the ventilator 
near Newton tunnel. 

It was found to be in about the same condition as at the 



8 City Document — No. 19. 

time of the previous examination, April 14th. The springs 
spoken of in the last report to the Water Board, found 
within 1,500 feet of the lake, seem to have increased some- 
what in strength and volume of flow. During the time the 
water was drawn ofi", they brought in large quantities of fine 
sand. An attempt was made to stop their flow, but it met 
with little or no success. To make proper repairs in this 
portion of the conduit, considerable time will be required, 
as short sections must be dammed oflT, and the water kept 
down by Ijailing or pumping. 

Consu?nptio7i. — The divisions of the city supplied by the 
Cochituate works are : Boston proper, South Boston, 
Dorchester, and the greater portion of Roxbury. (A small 
portion of Roxbury is supplied by the Jamaica Pond Aque- 
duct Co.) Those supplied from the Mystic Works are 
Charlestown and East Boston. The West Roxbury and 
Brighton divisions are not yet provided with a public supply. 

The average daily consumption from the Cochituate works 
for each month of the past year has been as follows : — 



January 


Gallons. 

. 16,651,300 


July . 


Galloas. 

. 21,386,200 


February 


19,103,850 


August 


. 20,127,800 


March 


. 17,657,300 


September 


. 20,022,600 


April . 


. 15,929,600 


October 


. 19,320,900 


May . 


. 16,731,900 


November 


. 14,319,500 


June . 


. 19,239,750 


December 


. 16,407,950 



The average daily consumption for the year from the 
Cochituate works has been 18,074,900 gallons. 

During November and December, 57,191,258 gallons were 
supplied to the city proper from the Mystic works ; equiva- 
lent to an average daily supply of 1,468,578 gallons in 
November, and 423,675 gallons in December, and to an 
average daily supply of 156,690 gallons for the year. The 
Jamaica Pond Works supply from two to three hundred 



Report of City Engineer. 9 

thousand gallons per day (say 250,000), to its consumers in 
Eoxbury ; hence the average daily consumption for the year, 
in the four first-named divisions of the city, has been about 
18,482,600 gallons. 

High Service. 

Parker Hill Reservoir. — At the time of the last annual 
report, the work of building a high level reservoir on Park- 
er Hill had begun, under a contract with Messrs. Tarbell 
and Hayes. On Nov. 2d it was so far completed that 
water was let in, and the process of filling commenced. 
Since that date it has been in daily use. It is now entirely 
finished, except a small amount of work upon the gate-house 
and gates, and a small area of bank to be soiled. The work 
is of very substantial character, and has been very faithfully 
carried out, under the direction of Mr. Wilbur F. Learned, 
one of the assistant engineers of this department, by Messrs. 
Tarbell and Hayes, contractors for the reservoir proper; 
Messrs. J. W. Colburn and Co., contractors for the gate- 
house, and the Boston Machine Co., contractors for the 
gates. 

The reservoir will hold 7,200,000 gallons above a plain, 
2^ feet above the bottom of the out-flow pipe. The area of 
the water surface, when at high-water mark, is 1.47 acres, 
and its elevation is 219 feet above tide marsh level. The 
elevation of the top of the bank is 222 feet ; of the bottom 
of the out-flow and in-flow pipes, 197.50; of the sills for 
the stop-planks, 196.25 ; and of the lower floor of the gate 
chamber, 196 feet. 

Pumps. — The pumping engines have worked very satis- 
factorily during the past year, and are now in good condition. 
The average daily quantities of water pumped for each 
month of 1874 have been as follows : — 
2 



10 



City Document. — No. 19. 



January 


Gallons. 

1,097,730 


July . 


Gallons. 

. 1,212,880 


February 


1,312,274 


August 


1,206,110 


March 


1,160,748 


September 


. 1,283,680 


April . 


1,119,266 


October . 


1,094,729 


May . 


1,171,483 


November 


1,649,481 


June . 


. 1,253,333 


December 


1,580,163 



During November and a part of December the reservoir 
was filling, which fact accounts, in part, for the large aver- 
ages of those months. 

The average daily quantity pumped for the year has been 
1,261,823 gallons, an increase of 23^ per cent, above the 
quantity in 1873. 



DISTRIBUTING SYSTEM AND PIPE PLANS. 

The following extract from the report of Assistant Engi- 
neer Dexter Brackett will show the work that has been done 
in enlarging and extending the pipe system of distribution, 
etc. : — 

" Water Pipes. — During the past year important changes 
have 1)een made in the distribution of the city proper. The 
enlargement of the pipes which was commenced in the Burnt 
District in 1873, has this year been extended through 
other portions of the city proper. 

" The following are among the most important of the 
changes : — 

Tremont street from Boylston to School, enlarged from 6" to 16" 



Cornhill " 
Temple place 
Sudbury street 
Hanover " 
Portland " 
Merrimack " 
Salem " 



Court to Devonshire, 
Tremont to Washington, 
Court to Portland, 
Union to Court, 
Hanover to Merrimack, 
Causeway to Portland, 
Hanover to Charter, 



6" to 12" 
4" to 12" 
6" to 8" 
6" to 12" 
6" to 8" 
G" to 12" 
6" to 8" 



Report of City Engineer. 



11 



Comm'l street from Prince to Fleet, 

North " 

Beacon ' 

Beach ' 

South ' 

Lehigh ' 

Albany ' 



enlarged from 6" to 12' 



" Commercial to Fleet, " ' 


« 6" to 8" 


" Somerset to Joy, " ' 


' 6" to 12" 


" Federal to Harrison av. " ' 


' 6" to 12" 


" Beach to Lehigh, " ' 


' G" to 12" 


" South to Albany, " ' 


' G" to 12" 


" Dover to Way, " ' 


' 6" to 12" 


" Curve to Harvard, " ' 


' 6" to 12" 



"111 South Bostoii the following changes have been 
made : — 

Dorchester av., from Dorchester street to Seventh, enlarged from 8" to 12" 
Seventh street " " " to Dor. av. " " 6" to 12" 

Eighth " " " " to L street, " " 6" to 12" 

Granite " " Second st. to Mt. Wash'n av. " " 6" to 12" 



"lu the City proper 161 Lowry hydrants have been estab- 
lished, and 113 hydrants of the old pattern abandoned. 

"In South Boston 92 Lowry hydrants have been estab- 
lished, and 54 Boston hydrants removed. 

" The 24-inch main connecting the force main with Parker 
Hill reservoir, and the 20-inqh high-service main through 
Pynchon, Tremont, Northampton streets and Columbus 
* avenue to Berkelej^ street, with the 12 and 16 inch mains 
from thence to Beacon Hill and South Boston, have all been 
completed during the past year. 

" The 24-inch main in Dorchester has been extended from 
Upham's corner to the junction of East street and Dorches- 
ter avenue. 

" During the year about 27 miles of pipe have been laid, 
and 457 Lowry h3^drants established. 

"Pipe Plans. — The plans showing the location of the 
pipes, gates, and hydrants have been corrected as usual. 

" Four plans, showing the pipes in South Boston, on a scale 
of 100 feet to an inch, have been made, so that we now have 
the entire distribution shown on this scale, with the excep- 
tion of that of East Boston. 



12 CiTT Document. — No. 19. 

"A large plan, showing the entire distribution of the city, 
is practically completed. 

"Three plans, showing the pipes and hydrants of the city 
proper, South and East Boston, have been prepared for the 
use of the Fire Commissioners. 

" The j)lan belonging to the Mystic Water Board, showing 
the water-pipes, gates, and hydrants in Charlestown, has been 
corrected." 

Survey of West Koxbury and Brighton. 

In September surveys to determine the elevation of the 
streets and houses in West Roxbury and Brighton were com- 
menced, and are now nearly finished. These surveys were 
authorized by an order of the City Council, passed June 6th, 
and are made with reference to a pipe system of distribution 
for these divisions of the city. The work is paid for from a 
special appropriation for the Water Department, and is done 
by a corps of temporary assistants. 



Flax Pond, and Jajviaica Pond Aqueduct Co. — Supply 
or Water for West Roxbury and Brighton. 

On November 21st, an order passed the City Council di- 
recting the City Engineer to make surveys and measure- 
ments to ascertain the actual amount of water that can be 
furnished from Flax, Sluice and Cedar ponds. 

The measurements were taken during December, and a 
report was submitted Dec. 21st. (City Doc. No. 110.) The 
order grew out of an offer of the Flax-pond Water Co. to 
supply East Boston with water. 

On December 21st, another report (City Doc. No. 108) was 
submitted, in answer to a vote of the Joint Standing Com- 
mittee on Water, referring " the petitions of John C. Pratt, 
and G. Winthrop Coffin, that the city would purchase 



Report of City Engineer. 13 

Jamaica pond, to the City Engineer, with request that he 
report the tacts as to the vaUie of the property in question, 
and the best method of supplying West Roxbury and 
Brighton with water." 

Additional Supply. 

No definite scheme of works for an additional supply of 
water has yet been adopted, although several reports, with 
estimates of various schemes for bringing water from a num- 
ber of sources, have been made and presented to the City 
Coimcil during the past year. 

The reports of Messrs. Kirkwood, Francis, and Horsford, 
upon the quantity and quality of the water to be obtained 
from the Mystic valley, together with one from Mr. W. F. 
Davis, Water Registrar, upon waste of water (City Doc. No. 
134, 1873), were presented by the Water Board in January. 

On January 29 two orders were passed, one requiring 
the Joint Standing Committee on Water, to " report upon 
the possibility and expense of adding to the waters of the 
Mystic pond a supply sufficient for the use of the city, by 
connecting said pond with Shawshine, Concord, and Mer- 
rimac rivers, or either of them ; " the other requiring the 
committee " to consider the expediency of making a perma- 
nent water connection between Farm pond and Lake Cochit- 
uate, build a conduit from Lake Cochituate to Chestnut Hill 
reservoir," etc. On February 16, it was ordered, "that the 
Joint Standing Committee on Water ascertain, by analysis 
or otherwise, the purity of the water of Charles river, at the 
most expedient point of taking the same for the use of the 
City of Boston ; " and on March 23, it was further ordered 
that the same committee " be requested to have accurate sur- 
veys made, under the direction of the City Engineer, to as- 
certain the water-shed of Mystic pond." 

In the latter part of April the committee transmitted to 



14 City Document. — No. 19. 

the City Council tlie report of the City Engineer upon the 
above subjects, and presented with it majority and minority 
reports ; also a report of a sub-committee upon mill damages 
on the Subdury and Charles rivers. (City Doc. No. 38, 
1874.) 

In May a preliminary report upon the cost of works to 
bring the waters of Charles river to the city was made to 
the Committee on Water, by the City Engineer, in obedience 
to an order passed by City Council May 4. 

On June 15 it was ordered " that the Joint Standing 
Committee on the Water Department ascertain and report 
whether the present source of our water supply from Lake 
Cochituate and Mystic lake combined, can be so utilized as 
to give an adequate water supply to the city in a season of 
drought," etc. ; and on the 29th of the same mouth it was 
ordered that the committee " be requested to examine the 
Charles river, and report in print, upon its availability as a 
source of supply," etc. The report of the City Engineer 
upon these subjects was made Oct. 10th (City Doc. No. 
85), and was transmitted to tlie City Council by the commit- 
tee in the latter part of that month. 

In obedience to an order passed June 15, a report (City Doc. 
No. 102) was presented in December to the City Council by 
the commission of three physicians, appointed by His Honor 
the Mayor " to examine and report upon the comparative de- 
sirabilit}^ on sanitary grounds of the Subdury, Mystic, 
Shawshine and Charles river waters." 

In November an order was passed, requesting His Honor 
the Mayor, to petition the Legislature for the right to take a 
supply of water from Charles river. 

The request of the Water Board, made during the latter 
part of 1873, that it be authorized to take land and water 
rights, under the provisions of the Sudburj^-river act, was 
refused by a vote of the Common Council, December 23d ; 
but on December 31st the vote was reconsidered, and the 



Report of City Engineer. 15 

Board Avas authorized to take the waters of the river, and 
also lauds for building storage basius, but was prohibited 
from incurring new liabilities for the construction of a 
conduit from the river to Chestnut Hill reservoir. 



BEIDGES. 

The usual annual examination of all the bridges within the 
city limits, open to street and foot travel, has been made, 
and the results of this examination respecting the condition 
of the bridges as to safety and need of renewal or repairs, 
are given in the following pages. 

Several written reports of special examinations of various 
bridges have been made during the year, and transmitted 
with such recommendations as were deemed necessary, to 
the departments having these bridges in charge. 

These reports will be found in the appendix. 

The following is a list of the bridges inspected. The 
annexation of a portion of Brookline added two to the list 
of last year ; one (Athens street) has been built during 
the year, one (Eastern Avenue) is partially completed ; 
and four over railroads in the portion of Charlestown near 
Somerville, were inadvertently omitted from last year's re- 
port. 

Those marked with an asterisk are over navigable waters, 
and are each furnished with a draw. 

1st. — Bridges wholly supported by the City. 

* Albany street over Eoxbury Canal. 

Ashland street, Ward 17, over Boston and Providence R. R. 
Athens street over N. Y. and N. E. Railroad. 
Berkeley street over Boston and Albany Railroad. 
Berkeley street over Boston and Providence Railroad. 

* Broadway over Fort Point Channel. 



16 City Document. — No. 19. 

Brookline avenue over Muddy River, Ward 15. 

* Charles River from Boston to Charlestown. 

* Chelsea street from East Boston to Chelsea. 
Columbus avenue over Boston and Albany Railroad. 

* Commercial point or Tenean, Ward 16. 

Dartmouth street over Boston and Albany and Boston and 

Providence Railroads. 
Dorchester street over Old Colony Railroad. 

* Dover street over Fort Point Channel. 

* Eastern av. over " " ♦ ' 

* Federal street over " " " 

Ferdinand street over Boston and Albany Railroad. 
Huntington av. over " " " " 

* Maiden bridge from Charlestown to Everett. 

* Meridian street from East Boston to Chelsea. 
Milldam over Back Bay Sluices. 

* Mount Washington avenue over Fort Point Channel. 
Newton street over Boston and Providence Railroad. 
Public Garden foot-bridge. 

Shawmut avenue over Boston and Albany Railroad. 

* Warren bridge from Boston to Charlestown. 
Winthrop bridge from Breed's island to Winthrop. 

2d. — Bridges of which Boston supports the Part 

WITHIN ITS LmiTS. 

* Cambridge street from Brighton (Ward 19) to Cambridge. 

* Chelsea bridge from Charlestown to Chelsea. 

* Essex street from Ward 19 (Brookline) to Cambridge. 

* Granite bridge from Dorchester (Ward 16) to Milton. 
Longwood avenue from Ward 15 to Brookline. 
Mattapan from Ward 16 to Milton. 

Milton " *' /' " 

* Neponset from Ward 16 to Quincy. 

* North Beacon street from Ward 19 to Watertown. 

* North Harvard street " " " Cambridge. 



Report of City Engineer. 17 

* Prison point from Charlestown to Cambridge. 

Spring street from West Roxbury (Ward 17) to Dedham. 

* Western avenue from Ward 19 to Cambridge. 

* Western avenue " *' *' Watertown. 

3d. — Bridges of which Boston pays a Part of the 
Cost of Maintenance. 

Albany street over Boston and Albany Railroad. 

* Canal bridge from Boston to Cambridge. 

* West Boston bridge from Boston to Cambridge. 

4th. — Bridges supported by Railway Corporations. 

1st. — Boston and Albany Railroad. 

Harrison avenue. 
Market street, Ward 19. 
North Beacon street, Ward 19. 
Tremont street. 
Washington street. 

2d. — Boston and Providence Railroad. 
Beech street. Ward 17. 
Belle vue avenue. Ward 17. 
Bellevue street, " " 
Canterbury street, Ward 17. 
Centre street or Hog bridge. Ward 15. 
Centre and Mt. Vernon streets. Ward 17. ^ 

Park avenue, Ward 17. 

3d. — Boston and Maine Railroad. 

Mystic avenue. 
Winter Hill road. 

4th. — Eastern Railroad. 
Mystic avenue. 
Winter Hill road. 
3 



18 City Document. — No. 19. 

5th. — New York and New England Railroad. 
Broadway. 
Dorchester avenue. 
Fifth street. 
Fourth street. 
Harvard street, Ward 16. 
Madison " " " 

Norfolk '* " " 

Norfolk <'<<»' 
Second street. 
Silver street. 
Sixth street. 
Third street. 
Washington street, Ward 16. 

6th. — Old Colony Railroad. 
Adams street. 

Ashmont street, and Dorchester avenue. 
Commercial street. 
Savin Hill avenue. 

Kecapitulation. 

1. Number wholly supported by Boston . . .27 
n. Number of which Boston supports the part within 

its limits ....... 14 

HI. Number of which Boston pays a part of the cost 

of maintenance . . . . . . • 3 

rV. Number supported by Railway Corporations : — 

^ 1. Boston and Albany ...... 5 

2. Boston and Providence ..... 7 

3. Boston and Maine . . . . . .2 

4. Eastern ........ 2 

5. New York and New England . . . .13 

6. Old Colony 4 

Total number . . . . .77 



Report of City Engineer. 19 

I. — BRIDGES WHOLLY SUPPORTED BY BOSTON. 
* Albany st. Bridge (over Roxbury Canal). 

The statement iu last year's report of the condition of this 
bridge applies with equal force at the present time. The 
conclusion of that statement was : " It is now in poor con- 
dition, but may be made to do service for a while longer 
by frequent repairs." The bulkheads at the ends of the 
bridge have given considerable trouble this winter, and one 
or both must be rebuilt in the spring. 

The cost of repairs on this bridge during the year has 
been $287.58. 

ASHLAND-ST. BrIDGE (oVER THE BoSTON AND PROVIDENCE 

Railroad, Ward 17). 

This is a small wooden bridge, 22| feet in width, and 30 
feet span, built in compliance with an order of the Norfolk 
County Commissioners, dated May 13, 1856. Its abutments, 
of dry rubble masonry, are within the location lines of the 
Boston and Providence Railroad, and as that corporation has 
given notice to the city that it desires the full width of its 
location at this point, for the purpose of laying additional 
tracks, a new bridge of greater span will be required. 

Plans have been prepared for an iron bridge of 70 feet 
span, with rubble masonry abutments laid in cement, and, as 
the necessary orders for its construction have passed the 
City Council, it is probable the work will be commenced 
early in the season. 

The present bridge is in poor condition, and would re- 
quire a considerable outlay for repairs, were it not so soon to 
be removed. 



20 CiTT Document. — No. 19. 



Athens-st. Beidge. 



In connection with the laying out of Athens street in 
South Boston as a public highway, a bridge has been built 
over the New York and New England Eailroad. The rail- 
road at this point is in a cut, the sides of which are sustained 
by retaining walls, the partial use of which for abutments 
has made the building of the bridge practicable at a moderate 
expense. 

Plans were made in September for an iron bridge with its 
abutments ; the work was advertised for proposals, and on 
the 6th of October a contract was made with Colby & 
Trumbull, the lowest bidders, for doing the work. 

The Eoxbury stone retaining wall on the easterly side of 
the railroad was not deemed of sufficient strength for use as 
an abutnjent ; it was therefore removed, and an abutment 
built having a granite face with Roxbury stone backing. 

The foundation course of this abutment is 9 feet 6 inches 
wide, and 3 feet thick, the bottom being placed 4 feet below 
the railroad track. The abutment is 8 feet wide at the base, 
and 3 feet 9 inches wide at the top, with bridge-seat of 
granite 4 feet 3 inches wide, and 1 foot 6 inches thick. 

The retaining wall on the westerly side, being in better 
condition than that on the easterly, was used as an abutment 
after removing and rebuilding about 4 feet in height of the top. 
This abutment was anchored by means of three 1^ inch rods, 
to a wall 3 feet 6 inches wide, and 5 feet high, extending 
across the street 25 feet from the face of the abutment. The 
bridge-seat course has the same dimensions as that on the 
easterly abutment. All the stone masonry is laid solid in 
cement mortar. 

The bridge consists of four wrought-iron girders, 22 inches 
high at the centre, and 17 inches at the ends, and each 31 
feet long ; they are placed 6 feet 8 inches apart on centres 
and tied together with |-inch rods at the top, and 3 X ^^ 



Eeport of City Engineer. 21 

inch bars at the bottom. The roadway timbers are 
4 X 14 inches, and 4 X 16 inches, placed 3 feet apart 
on centres, fitted between the girders, and resting on the 
lower flange, with furring pieces to conform to the crown of 
girders. The roadway planking is in two courses, the lower 
of 4-iuch creosoted spruce, the upper of 2-inch spruce. 

The bridge is 20 feet wide between the fences, the same 
width as the street. The roadway is 14 feet, and the side- 
walks each 3 feet wide. 

Assistant Dexter Brackett has been in charge of the work, 
which was completed in December, at a total cost of 
$3,133.50 for the bridge and its abutments. 

Berkeley-st. Bridge (over B. & A. Railroad). 

Attention has been called in former reports to the light 
proportions of this structure. The web plates of the trusses 
are very thin and badly warped, and the sidewalk floor 
timbers are of light section. 

The bridge, however, still continues to do its work, and 
but little change is noticeable from year to year. It is now 
apparently in as good order as it was when reported upon 
last year. 

Berkeley-st. Bridge (over B. & P. Railroad). 

The fences on this bridge are in bad order, the concrete 
sidewalk on one side is completely disintegrated, and should 
be renewed, and the entire bridge needs painting. 

No perceptible change has taken place in the southerly 
abutment, which has been cracked for several years. 

* Broadway Bridge. 

This bridge has been out of use since May 7th, on account 
of the rebuilding of the draw and its foundation pier. Ad- 



22 City Document. — No. 19. 

vantage has been taken of the closing of the bridge to travel, 
to repair the section between the Old Colony Railroad and 
Foundry street. This section was in very bad condition, 
owing to the lateral expansion of the roadway, caused, 
probably, by the freezing of the wood pavement when sat- 
urated with water. By this expansion the outer longitudinal 
beams on each side were so much inclined as to greatly dimin- 
tish their supporting power, and from the increase of distance 
between the tops of the beams several of the iron roadway 
plates had fallen from their places, and the bearing of others 
had been rendered insecure. The fences were also thrown 
out of line, and their attachments to the bridge broken in 
most places. 

The several parts of this section have been restored to 
their normal j^osition, and an attempt has been made to pre- 
vent further lateral expansion by means of wrought-iron rods, 
provided with nuts and strong cast-iron washers. These rods 
extend across the roadway at short intervals, and pass through 
7 X 10 inch longitudinal timbers on each side adjoining the 
cast-iron curb and also through the curb itself. 

Tlie warped condition of the arched girders of the spans 
over Foundry and Lehigh streets has been mentioned in 
former reports, but with the exception of the application of 
temporary braces, nothing has been done to remedy this 
defect. These girders could be relieved of a large portion 
of the weight they carry, by the substitution of a burnettized 
plank flooring for the cast-iron roadway plates. On the 
Foundry-street span the estimated weight of the plates is 
about 85,000 lbs; a plank flooring would weigh about 
18,000 lbs ; the permanent load on each girder could there- 
fore be reduced about 17 tons, and a similar reduction of 
permanent load could be efiected on the Lehigh-street span. 
Reference lines have been established, for the purpose of noting 
any further movement of these girders, and in case of any 
change for the worse it will be necessary to relieve them 



Report of City Engineer. 23 

from tiie unnecessary strain caused by the weight of the 
roadway plates. 

Some fitting will be required to make a proper joint be- 
tween the ends of the fixed spaus and the new draw when 
completed ; the gates will need some repairs, and the bridge 
should be painted before it is again opened for travel. 

The sheet piling of the draw pier has been badly eaten 
by worms, and will probably last but a few years longer. 
It is so much weakened that a sharp blow, such as it is 
at any time liable to receive from a vessel, may break in 
a considerable portion of it. In anticipation of the necessity 
of soon rebuilding the whole pier, plans have been prepared 
for this purpose, and a license to do the work obtained from 
the Harbor Commissioners. 

The repairs on the fixed portion of the bridge, made under 
the dii'ectiou of this department, have cost $2,932.36 for the 
year. 

Plans and specifications were prepared in the winter and 
spring for a new foundation pier, and specifications were 
written for a new draw.' s~ ti ^f£t[. 

,.>-7Proj)osals for building the pier and for a new draw were 
invited in June. The contract for building the pier was 
awarded to Messrs. Colby & Trumbull of Lawrence, Mass., 
for the sum of $51,000. 

The bid and designs of the Watson Manufacturing Com- 
pany of Paterson, N. J., for a new draw were accepted, and 
a contract made with it to furnish and erect the draw for 
$26,680. 

The old draw, with the exception of the parts reserved for 
use in the new foundation pier, was sold to Mr. John 
Cavauagh, of Boston, for $2,200, and was taken down and 
removed by him. 

The new foundation pier is now in a forward state of com- 
pletion. The novelty of the design and peculiar character 
of a portion of the work have delayed its completion beyond 



24 City Document. — No. 19. 

the time allowed by the contract. It could, however, hardly 
be expected that it would progress with the same rapidity as 
work with which contractors are more familiar, and the many 
difficulties encountered, although successfully overcome and 
satisfactory results obtained, have occasioned even more 
delay than was anticipated. 

The construction of the new foundation pier and draw has 
involved many questions of engineering interest, and a full 
description of the work will be given in the next annual 
report, but is deferred at the present time on account of the 
non-completion of the entire structure. 

Brookline-ave. Bridge (over Muddy Eiver). 

This is a small bridge, in good order. It has been widened 
about 8 feet, in connection with the widening of the avenue by 
filling it to the full width of its location, and has also been 
replanked. 

* Charles-river Bridge (from Boston to Charles- 

town). , . 

This bridge and the "Warren have, by the annexation of 
Charlestown, come under the same control as the other city 
bridges, but as the Commissioners had charge of them for a 
considerable portion of the year, I have requested Mr. 
Wightman, Assistant City Engineer, who has acted as 
engineer for the Commissioners on these and on the West 
Boston and Canal bridges, to report on their condition. 

His report will be foimd in the Appendix. 

* Chelsea-st. Bridge (from Chelsea to East Boston). 

As this bridge was rebuilt, with the exception of the draw, 
in 1873, it is in good order. 



Report of City Engineer. 25 

The draw has been replanked, and slight repairs made upon 
it. The Sampson posts are not plumb, but as the draw is not 
opened in the winter, no strain of any consequence comes on 
them, and they will not require attention till spring. 

The cost of repairs, made under the direction of this 
department, has been for the year, $321.00. 

columbus-ave . bridge (over boston and albany 
Railroad) . 

A special examination of this bridge has been made by 
Mr. Manley, with reference to the expediency of increasing 
the permanent load on the main girders by the laying of a 
new high-service water-main. His report will be found in 
the Appendix.* 

The result of this examination was the building of an in- 
dependent lattice girder, of sufficient strength to carry safely 
the water-pipe Avhen filled with water, and a portion of the 
sidewalk load. To prevent injury to the water-pipe from the 
vibration of the main bridge under a moving load, the new 
girder was connected with one of the sidewalk girders only, 
and all connection with the roadway girders was severed. 

The bridge has not been relieved from the weight of un- 
necessary floor planks, to which attention is called in Mr. 
Mauley's report. It would be improved by scraping and 
painting the iron work. 

The cost of repairs on this bridge, by the Paving Depart- 
ment, was $160.()8,_ 

* CoiiiiViERCiAL Point or Tenean Bridge (Ward 16). 

No special repairs have been required on this bridge and 
it is in fiir order. The substructure is built. with spruce 
piles, and will not probably last many years longer. 

It would be desirable when it becomes necessary to re- 
4 



26 City Document. — No. 19. 

build the bridge, which consists of little else than a draw, to 
continue the solid causeway across the channel, leaving only 
a culvert for the tidal flow. The basin above the bridge Is 
seldom used except as a mooring place for yachts, and will 
never, in all probability, be used for more important 
purposes. 

D^^RTMOUTH-ST. BrIDGE (OVER BoSTON AND AlBANY, AND 

Boston and Providence Eailroads). 

Extensive repairs were made on this structure last year, 
and, so far as a supei-ficial examination shows, it is now in 
fair condition. The decay of the wood-work of the trusses 
doubtless still continues, but as a thorough inspection of it 
involves considerable work in tearing up flooring and sheath- 
ing, it has been postponed until spring. So shbrt a time has 
elapsed since the new work was finished, it is not probable 
that any dangerous change has taken place. The auxiliary 
trusses erected last year should be painted. 

Dorchester-st. Bridge (over Old Colony Railroad). 

This is an iron bridge, in good order, and will require only 
ordinary repairs to the wood-work. 

* DovER-ST. Bridge (over Fort Point Channel). 

No material change has been noticeable in this bridge dur- 
ing the year. Repairs to serve temporary purposes have 
been made, but more extensive ones will be required if the 
widening and general reconstruction recommended in the 
last annual report should not be commenced this year. 

Broadway bridge being closed, the travel over this bridge 
has been greatly increased, and the inconvenience resulting 
from its narrow width has been more than ever apparent. 

The cost of repairs for the year, made under the direction 
of this department, has been $1,993.17. 



Report of City Engineer. 27 



* Eastern-ave. Bridge. 



Several designs, with estimates for building this bridge and 
its approaches, were presented to the Committee on Streets 
last spring. The question of grade and location had been 
determined by the committee of the previous year, after 
considerable discussion, and the plans submitted were drawn 
in accordance with the grade and location decided upon, and 
varied only in details of construction. 

Of the plans submitted, the one adopted was, — after re- 
ceiving the approval of the Harbor Commissioners and the 
Governor and Council, as provided in the agreement between 
the State and other contracting parties, under which the 
bridge is built, — advertised for proposals. Boy nton Bros, 
and Freeman of Boston were the successful bidders, and in 
July a contract was made with them to build the entire 
structure, except the iron draw. The contract amounts to 
about $140,000, the price to be paid being dependent upon 
the quantities of certain kinds of work required. 

Proposals were also invited for an iron draw, designs to be 
submitted by the bidders under a general specification similar 
to that for the Broadway, and in August a contract was made 
with the Phillipsburg Manufacturing Co., of Phillipsburg, 
N. J., to build and erect a draw for $19,925.00. 

The grade of the bridge at the draw had been established 
at 26 feet above mean low water, with slopes, each side, of 
14 inches in 100 feet to a grade of 17 feet. 

The plans had been drawn and the contracts made on the 
basis of this grade ; the work of building had already been 
commenced, and considerable progress made, when the grade 
was objected to by the Boston Wharf Company. A hearing 
before the Committee on Streets was requested by the Com- 
pany and granted, after which the committee voted to rec- 
ommend to the City Council, the adoption of a lower grade, 
provided the city should not thereby be subjected to any 
additional expense beyond the contract price. 



28 City Document. — No. 19. 

As the consent of the Governor and Council, and the 
Harbor Commissioners, as well as the consent of the City 
Council, were necessary before any change of the grade could 
legally be made, work was stopped on all parts of the bridge 
affected by the proposed change. The Boston Wharf Com- 
pany were to pay all expenses and damages resulting to 
the contractors from the stoppage of the work, whether the 
grade was lowered or not. 

The requisite authorit}^ has been received and all the nec- 
essary papers executed for lowering the grade at the draw 
to 21 feet above mean low water, with inclines on each side 
of 18 inches in 100 feet to a grade of 18 feet. 

Work has not as yet been resumed on the bridge, but as 
the grade changes proposed did not affect the foundation 
pier and draw pier to such an extent as to render a discon- 
tinuance of work necessary, the contractors have continued 
the construction of them until the recent cold weather made 
it advisable for them to stop. 

The amount paid the contractors to January 1st is 

),389.32. 



*Federal-st. Bridge (over Fort Point Channel). 

This bridge is in good order. 

The plan of making the draw in two parts, opening in op- 
posite directions, has proved very successful, and has given 
general satisfaction. Only ordinary repairs will be needed 
in the year to come unless from accidents. 
The amount paid for repairs under the direction 

of this department has been . . . $974 69 

Amount expended under other direction . . 802 70 

Total ^ . $1,777 39 



Report of City Engineer. 29 

Ferdinand-st. Bridge (over B. & A. Railroad). 

A special report by Mr. Manley, which, with my endorse- 
ment, will be found in the Appen^lix, gives the result of an 
examination of this bridge. 

A short time after that report was wi-itten a variety of 
plans and estimates were made for a new bridge, and for re- 
placing the wooden bulkhead at the side of the street with a 
retaining wall. The agitation of the question of the exten- 
sion of Broadway, by which either Castle and Ferdinand 
streets or Pleasant street would become a portion of this 
thoroughfare, was. commenced about this time, and nothing 
has been done toward a new bridge. Plans for new wooden 
sidewalk trusses were made, but they have not been built. 
The bridge remains as it was at the beginning of the year, 
with the exception of new floor plank. 

Huntington-ave. Bridge (over B. & A. Railroad). 

This bridge remains in the state descrilied in the report of 
last year. The movement in the abutments continues at 
about the rate of the j^ear before ; the greatest movement 
being 1^ inches in the northerly abutment, and | of an inch 
in the southerly abutment for the year 1874. The iron work 
is in need of painting. 

Malden Bridge (from Charlestown to Everett). 

By Chapter 139, Acts of 1874, the care, support and su- 
perintendence of this bridge devolves on the city of Boston. 

The bridge was built by the Proprietors of Maiden bridge 
in 1787, under authority granted by the Legislature, and was 
maintained by these proprietors until April 1, 1859, when it 
was laid out as a public highway by an act of the Legislature. 
It has since that time until the present year been supported 
by assessments levied upon the several cities, towns, and cor- 



30 City Document. — No. 19. 

1 orations benefited by it, and the care and superintendence 
were in charge of the city of Charlestown. 

Tiie bridge, with the exception of the draw, is very old, and 
is in an unsafe condition. The piles have settled badly, and 
many of them are rotten and shattered ; portions of the 
flooring are also rotten, and all parts of the bridge are heav- 
ily loaded by the mud and gravel covering. 

By the settlement of the piles on the centreline of the bridge, 
water is held as in a trough, after rains and during thaws, and 
the roadway not being paved is usually covered with a deep 
layer of mud, or, when the mud dries, of dust, making it one 
of the worst highways leading from the city. 

The street connecting with the bridge has been paved, and 
the bridge itself should be rebuilt and paved the coming 
season. 

The draw is a new one, built a few years ago by Ross & 
Lord, and, although very narrow, is in good condition and 
will require only ordinary repairs. 

The cost of repairs for the year has been $864.98. 

In view of the poor condition of this bridge, the Chelsea 
bridge, and Meridian-street draw, it will be necessary to re- 
build them as soon as possible, and it is evident that it will 
greatly inconvenience the travel from the city to the adjacent 
sections of country on the north, if the three bridges should 
be closed to travel at one time. I am, therefore, of the 
opinion that, as neither can be rebuilt without stopping the 
travel over it, it will be better to rebuild the Maiden bridge 
and the Meridian-street draw this year, and keep Chelsea 
bridge in use a year longer. My reasons for this opinion are 
as folloAvs : — 

1. Chelsea bridge is a comparatively simple structure, 
its weak points are open to inspection, and, from its being 
over flats, exposed at low water for a large portion of its 
length, all parts of it are easily accessible for repairs, incase 
of accident. This is not the case with the Meridian-street 



Report of City Engineer. 31 

draw, nor the Maiden bridge, as the structure of both is more 
complex 

2. Chelsea bridge can be temporarily strengthened by 
cross-bracing the piers with cheap lumber, and by other inex- 
pensive repairs, which will not necessitate closing it to travel, 
while the dangerous portions of the other bridges cannot be 
rendered safe without practically rebuilding them. 

3. The work on either the Meridian-street draw or Maiden 
bridge, or on both of them, can certainly be done in one sea- 
son, during which such part of the work of filling at Chelsea 
bridge as can be accomplished without closing the bridge 
may be done. 

4. Chelsea bridge being supported by two cities, it is de- 
sirable that they should agree upon a plan for widening and 
rebuilding it, and that the work should be done by each city 
on its ownrportion at the same time, thereby avoiding closing 
the bridge but once. These arrangements, and the settle- 
ment of the legal complications that will probably arise 
between the cities and the abutters and horse railway 
company, will take so much time that it is doubtful whether 
the work could be commenced in season to complete it this 
year. 

1^ Cr 2- -^* Meridian-st. Bridge. 

The sidewalks on this bridge have been put in good con- 
dition ; one section has been relaid with brick, and the re- 
mainder coated anew with coal tar concrete. 

No other repairs of any amount have been required on the 
fixed portion of the bridge, and it is now in good order. 

The draw was reported last year as being in an unsafe 
condition, and during this year it has been a continual source 
of expense to the city, delay and annoyance to the public, 
and anxiety and labor to those having the care of it. It was 
built in 1856, and has lasted longer than most structures of 



32 City Document. — No. 19. 

its kind. One of the snspension rods suddenly gave way 
last summer, and but for the fact that the draw had not 
swung clear of its landings it would probably have been 
broken in two. 

The Committee on Bridges have given orders for the prep- 
aration of plans for a new draw. 

Preliminary soundings have been made to determine the 
character of the foundation, but legislative action should 
be had before the plans can be completed. 

The existing openings for vessels are 60 feet Avide, the act 
authorizing the building of the bridge requiring them to be 
made that width. As these openings are wider by 24 feet 
than those in the bridges on Charles river, and 15 feet wider 
than in any other of the city bridges, it would seem to be an 
unnecessary width, and it is desirable on many accounts to 
lessen it. 

The cost of repairs on the bridge under the di- 
rection of this department has been '. . $1,799 92 
Cost of repairs under other direction . 319 06 



Total $2,118 98 

Mill Dam Bridge (over Back Bay Sluices). 
This bridge is in good order. 

* Mt. "Washington-ave. Bridge (over Fort Point 
Channel) . 

Is in good condition, none but ordinary repairs have been 
made. The draw pier will require attention soon ; the piles 
on its face are too far apart, and passing vessels break and 
tear off the plank. The piles have been cut so badly, by the 
continual spiking of plank, that special pains have to be 
taken to keep them in place. 



Eeport of City Engineer. 33 

The cost of repairs made under the direction 

of this department has been . . . $712 34 

Other repairs have cost . . . . . 501 81 



Total • $1,214 15 

WiNTHROP Bridge (from Breed's Island to Winthrop) . 

The phmking on this bridge was patched late in the fall, and 
in doing this work it was found that so many of the old 
planks are decayed at the bearings, it will be necessary to re- 
plauk the whole bridge early in the spring. A freight of 
plank can be landed at the bridge, and the work done with- 
out closing it to travel. 

The cost of repairs has been $229.17. 

Newtoit-st. Bridge (over Boston and Providence 

Eailroad) . 

The northerly abutment of this bridge, as stated in last 
year's report, is badly cracked. It is apparently worse than 
it was a year ago ; but as no exact measurements have been 
taken, the amount of movement is not known. 

The bridge is in good order, and no repairs have been 
required, as it is but little used. 

Public Garden Foot Bridge. 
This structure is in good condition. 

Shawmut-ave. Bridge (over Boston and Albany 
Eailroad) . 

This bridge is in good order, except that the parapet needs 
repairing. 



34 CiTr Document. — No. 19. 

* "Waeren Bridge (from Boston to Charlestown) . 

Mr. Wightman's report on the condition of this bridge will 
be found in the Appendix. 



n. — BRIDGES OF WHICH BOSTON SUPPORTS 
THE PART WITHIN ITS LIMITS. 

* Cambripge-st. Bridge (from Ward 19 to Cam- 

abridge) . 

This bridge has been rejDlanked duriag the year, and other 
repairs of minor importance have been made. It is now in 
good condition. 

The cost of the work upon it, done under the direction of 
this department, has been $349.24. 

* Chelsea Bridge (from Charlestoavn to Chelsea). 

The total length of this structure is 3,633 feet, of which 
Boston maintains 2,000 feet (stated by mistake in the last 
report as 2,333 feet) , except that the Lynn and Boston Horse 
Railway Corporation is required to plank one half the width, 
and to keep in repair the two lines of stringers which carry 
its track. 

As at the date of the last report, this bridge is in an unsafe 
state, though its condition has been somewhat improved 
during the year. 

The draw has been pretty thoroughly repaired, and is now 
in good order. A number of the worst piles have been re- 
placed by new ones, and the caps renewed or spliced; the 
stringers and planking are in good condition. The piles, as 
a whole, are in a dangerous state of wear and decay, and the 
cross-bracing is almost entirely gone, leaving the bridge free 
to sway with a passing load. 
y^As_has been before stated, from 1,200 to 1,500 lineal feet 



Eepoet of City Engineer. 35 

of the pile work may be replaced by solid filling. The 
Mystic-river corporation, and the Boston and Lowell Rail- 
road corporation have made propositions to the city to fill 
solid those portions which cross their lauds ; but the proposi- 
tions have not been accepted. 

The legal rights and obligations of the city, in this struc- 
tm*e and its location, are not well defined, and a question has 
arisen as to the width of location which the city owns across 
the lands of these corporations and at other points. Until 
this question is settled, or the rival claims are adjusted, by 
compromise or otherwise, the Committee on Bridges has not 
thought it prudent to take any steps towards rebuilding, as 
when rebuilt the bridge should be considerably widened. 

The cost of repairs made, under the direction of this de- 
partment, has been $1,187.47. 

*EssEX-ST. Bridge (from Ward 19 to Cambridge). 

This bridge became the property of the City of Boston in 
1874, through the annexation of a portion of the town of 
Brooldine. 

It was ])uilt by the proprietors of the Cambridge and 
Brookline Bridge, a company incorporated in 1850. It was 
rebuilt a few years ago, and the portion to be maintained by 
the city is in good condition ; one leaf of the draw, however, 
should have a new counter- weight. 

* Granite Bridge (from Dorchester to Milton). 

This bridge is in fair condition. It has required no re- 
pairs during the past year, but should be planked in the 
spring. 

Longwood-ave. Bridge (from Ward 15 to Brookline). 

A special report upon the condition of this bridge, and the 
repairs needed, was made by Mr. Mauley, December 20, 1873. 



36 City Document. — No. 19. 

(See report for 1873, page 60.) The work there recom- 
mended has been doue, and in addition the roadway was re- 
planked. These repairs render the bridge secm'e for the 
present, but it must be rebuilt at no distant day. 

The cost of repairs was $1,500, one half of which was 
paid by the town of Brookline. 

Mattapan Bridge (from "VYaed 16 to IVIilton), 

and 
Milton Bridge (from Ward 16 to Milton). 

These bridges are in good order. 

* Neponset Bridge (from Ward 16 to Quincy). 

Designs for rebuilding and widening that portion of the 
Neponset bridge, which is maintained by Boston, were fin- 
ished early in 1874, and it was expected that the work of 
rebuilding would be done last summer ; but an accident to the 
draw, which necessitated immediate and rather extensive re- 
pairs, made it advisable to repair the bridge as well ; this 
was done in such manner that the structure is in fair condi- 
tion for the traffic of the coming year. 

The cost of repairs has been $1,670.23. 

* North Beacon-st. Bridge (from Ward 19 to Water- 

tomt^) . 

This bridge is in good condition. 

* North Haevard-st. Bridge (from Ward 19 to 

Cambridge). 

Both the roadway and the draw pier of this bridge have 
been planked, and a shelter for the draw-tender has been 
built. 

It is now in g-ood order. 



Kepokt of City Engineee. 37 

The cost of repairs made under the direction of 

this department has been .... $1,017 45 
Cost of other repairs . . . . . 481 49 

Total $1,498 94 



* Prison Point Bridge (from Charlestown to Cam- 
bridge). 

The condition of this bridge is about the same as at the 
date of the last annual report. The draw-tender's house has 
been repaired, and a water-pipe has been laid for its supply. 

The cost of repairs has been $371.60. 

Spring-st. Bridge (from Ward 17 to Dedham). 
This bridge is in good condition. 

* Western-ave. Bridge (from Ward 19 to 
Cambridge) . 

The upper works of this bridge, with the exception of the 
draw, have been renewed, and a shelter built for the draw- 
tender. It is now in good order. 
The cost of repairs made under the direc- 
tion of this department has been . . $2,403 49 
Cost of other repairs .... 483 15 

$2,886 64 

* Western-ave. Bridge (from Ward 19 to Water- 
to wa ) . 

This is an old structure, with a badly located draw-way. 
The town of Watertowu has given its portion very thorough 
repairs during the last season, and the draw pier belonging 
to Boston has been rebuilt. The draw is in bad condition, 



38 City Document. — No. 19. 

and will need repairs or renewal in the spring, and the road- 
way of the bridge must be replanked. 
The cost of repairs has been $773.52. 

III. — BEIDGES OF WHICH BOSTON PAYS A PART 
OF THE COST OF MAINTENANCE. 

AxBANY-ST. Bridge (over Boston and Albany Railroad). 

It was stated in last year's report that this structure was 
soon to be removed to make place for one of longer span, to 
accommodate improvements in progress by the Boston & 
Albany Railroad, and that the change would be made at its 
expense. 

Nothing has, however, as yet been done by the corporation, 
and the bridge and its abutments are in the same condition 
as last year. 

Canal Bridge (from Boston to Cambridge). 

West Boston Bridge (from Boston to Cambridge). 

These two bridges are in charge of Commissioners. Mr. 
Wightman's report, in the Appendix, will give all requisite 
information as to their condition and the proposed or com- 
pleted improvements. 

IV. - BRIDGES SUPPORTED RY RAILWAY 
CORPORATIONS. 

The Appendix to la&t^year's report contained a special re- 
port by Mr. Manley, on the condition of the bridges of the 
Hartford and Erie (New York and New England) Railroad, 
which required inspection by this department. 

During the past year the condition of many of these 
bridges has been greatly improved. Of six bridges reported 
unsafe, three have been wholly rebuilt, and the most objec- 



Repoet of City Engineer. 39 

tionable portion of one other repaired. Two bridges classed 
as probably safe, but concerning which doubt existed, on ac- 
count of the difficulty of proper inspection, have also been 
rebuilt. 

Two bridges still remain in an unsafe condition ; the Sixth 
street and the Norfolk avenue No. 1. These bridges are de- 
ficient in strength by reason of their faulty design, independ- 
ent of any question of decay. 

Four bridges. Second street. Third street, Broadway and 
Fifth street, are old, and the plank and timbers more or less 
decayed. 

All other bridges within tlie city limits, maintained by 
railway corporations, and coming under the inspection of 
this department, are in good or fair condition, and require no 
special mention in this report. 



MISCELLANEOUS WORK AND CONSTRUCTIONS 

IN 1874. 

NORTHAMPTON-ST. DiSTEICT. 

A contract for filling this district was made with Phineas 
E. Gay, of Boston, April 15, 1874. He was to receive 
$6.40 per square (of eight cubic yards each), for all gravel 
delivered on the territory, and in addition to this sum $1.00 
jDer square for all filling between grade twelve and such 
higher grade as might be established or designated on any 
of the streets, ways or places in the district. 

By order of the Joint Special Committee on the district, 
the City Engineer was directed to measure the banks and 
furnish estimates of the amomit of gravel taken therefrom, 
and deposited on the district, and also to measure and esti- 
mate the amount deposited on the scveial estates and on the 
streets and passageways above grade twelve. 

The contractor began to deliver gravel July 17, 1874, 



40 City Document. — No. 19. 

and completed his contract Dec. 9, 1874, having delivered 
during that time 21,293 squares, or 170,344 cubic yards. 
The bank from which the gravel was taken is located at 
Springvale, on the New York and New England Railroad, 
about twelve miles from the district. 

A measurement of the banks was made before work was 
commenced, and every estate, street, and passageway on the 
district was levelled over. Monthly estimates have been 
made of the amounts taken from the bank, and the total 
amount subdivided for purposes of assessment, as ordered 
by the committee. 

Assistant E. W. Howe has had charge of the measure- 
ments, and two tallymen were appointed to keep account of 
the number of car-loads that left the bank, the number re- 
ceived on the district being kept by Mr. L. W. Knight, the 
superintendent of the district. The total number of car- 
loads removed from the bank was 39,319. The total num- 
ber received on the district, as reported by Mr. Knight, 
39,008, — a discrepancy of 311 car-loads, which were lost by 
the upsetting of cars, or used b}" the contractor for levelling 
up the track. 

SwETT-ST. Extension. 

Plans have been made for the water-ways or bridges over 
the openings required by the Harbor Commissioners to be 
left through the solid filling of the extension of this street 
across the South Bay. These plans have been submitted to 
the Harbor Commissioners, and a license for their construc- 
tion granted. 

Estimates of the amount of filling required for the street 
and for raising the railroad to pass over it, also estimates for 
the railroad bridge and abutments, and for building the 
water-ways, have been furnished to the Street Commis- 
sioners. 



Eeport of City Engeneee. 41 

Atlantic-ave. Retaining- Wall (near Russia 
Wharf) . 

Plans for this wall were prepared during the summer, and 
a contract made with Daniel Cram, August 25th, 1874, to 
build it. 

The work consists of short sections of wall across the 
heads of two docks, one on each side of Russia Wharf, and 
on the line of widening of Atlantic avenue (formerly Broad 
street). The wall is 23 feet high, 4 feet thick at the top 
and 15 feet at the base, including a projection of 2 feet of 
the footing course. 

It is built of New Hampshire granite, is well ballasted 
with oyster-shells and capped with a granite curb carrying 
a wooden fence with wrought-iron standards. The bottom 
rests on hard clay 6 feet below mean low water, all soft 
material having been removed by dredging. 

By arrangement with the abutters, the outer line of the 
wall at the top is 20 inches on their land. 

The contract price is $5,350 ; amount paid to January 1st 
was $3,623.25. 

Change of Location of the Eastern and Boston and 
Albany Railroads. 

By a resolve of the Legislature, approved May 22, 1874, 
the petition of the Mayor for a change in the location of 
these railroads in East Boston, to prevent the crossing at 
grade of important streets, was referred to the Railroad 
Commissioners, with instructions to consider and report upon 
the various questions relating to the subject as soon as prac- 
ticable. 

By direction of the Joint Standing Committee on Legisla- 
tive Matters, surveys and estimates were made by Mr. J. B. 
Cunningham, an engineer of experience in railroad affairs, to 
demonstrate the feasibility of the project from an engineer- 
6 



42 City Document. — No. 19. 

ing standpoint, and also to obtain such information as would 
be of value to the committee in making, on behalf of the 
city, a proper presentation of the subject to the Railroad 
Commissioners. 

The results of Mr. Cunningham's investigations, with my 
comments thereon, are embodied in a report to the committee 
(City Doc. No. 86, 1874). 

Seaverns-ave. Retaesting-Wall. 

Plans and specifications were prepared in June for a re- 
taining-wall of Roxbury stone to be located on the northerly 
side of Seaverns avenue (Jamaica Plain) . 

The contract for building it was awarded, June, 1874, to 
Thomas Dolan, for $1,985.00. 

The wall is 150 feet long, of an average height of 8 feet, 
and provided with a granite cap. It was substantially built 
under the supervision of an inspector (Mr. J. W. Coburn), 
and was completed August 6, 1874. 

Haerison-a ve . Retaining- Wall. 

During the fall there was built on the southerly line of 
Harrison avenue, between Hunnemau and Northampton 
streets, a rubble retainiug-wall with granite coping. The 
contractor, Mr. George Coyle, commenced work Sept. 21, 
1874, and the final estimate was made Dec. 11, 1874. 

This wall has a foundation of oyster shells, 7 feet wide and 
3 feet deep, and is 5 feet wide at the bottom and 6 feet high, 
with a rough-hammered granite coping 12 X 14 inches. All 
the masonry is laid solid in cement mortar, and the wall is bal- 
lasted in the rear and for a portion of its height on the front 
with oyster-shells. It is in four sections, measuring together 
408 lineal feet ; and a wall 300 feet in length, similar in 
design, built in 1872, but of which this wall is a continuation, 
was capped with a granite coping by the same contractor. 



Eeport of City Engineer. 43 

The contract price for the work was $8.00 per lineal foot, 
for the new wall, and $1.00 per lineal foot for the coping on 
the old wall. Mr. Nathan D. Whitman was employed as 
inspector. 

Yarmouth-st. Retaining-Wall. 

This wall is located at the end of Yarmouth street adjoin- 
ing the Boston and Providence Railroad. 

A contract for building it was made with Messrs. Clapp 
and Ballou, Oct. 17, 1874, for the sum of $4,097.00. 

The wall is built on piles, alternate rows of which extend 
into the street from the back of the wall.' Each row of piles 
is girder-capped with two 4 x 12-inch spruce sticks bolted to 
each pile. The wall is 91 feet long and 9 feet high, and has 
a 20 X 20-inch granite coping, carrying a tight board-fence 5 
feet high supported by iron standards. 

The work has been thoroughly done under the supervision 
of Mr. E. D. Swallow as inspector, and a final estimate upon 
it was made Dec. 26, 1874. 

Army and Navy Monument. 

By the terms of the contract with Mr. Martin Milmore for 
the erection of this monument, the City Engineer is required 
to make quarterly estimates of the work done and materials 
furnished in its construction. 

The contract was executed June 2, 1871, but none of the 
materials were delivered at the site of the work until early 
in October, 1874. 

A sub-contract was made Sept. 23, 1874, by Mr. Milmore 
with Messrs. Johnson & Richmond of this city, for the erec- 
tion of the monument, and by the terms of this contract the 
work was to be done to the satisfaction and acceptance of the 
superintendent of the work and the City Engineer. 

By direction of the Committee on the Army and Navy 



44 City Document. — No. 19. 

Monument, an inspector, Mr. E. D. Swallow, was appointed 
by this department to superintend the work. All the cut 
stone delivered were set in October. 

The first quarterly estimate was made October 31, 1874, 
the amount paid the contractor being $22,500. 



Frequent inquiry is made at this office, with regard to the 
width of the draw-openings in the bridges over tide-water 
in this city. I have recently had all of these openings 
measured, and the results, which may be of value to parties 
interested, are given in a table in the Appendix. 

Respectfully submitted, 

JOSEPH P. DAVIS, 

City Engineer. 



APPENDIX. 



Appendix. 



47 



TABLE 

Showing the widths of openings for vessels in all bridges 
provided with draws, in the City of Boston. 



Name of Bridge. 



Boston & Maine R. R 

Broadway (Boston side) 

Cambridge St. . 

Canal 

Charles River 

Chelsea 

Chelsea st. (East Boston side) 

" (Chelsea side) 

Commercial Point 

Dover st 

Eastern R. R 

Essex st 

Federal st 

FltchburgR.R 

" " (for teaming Freight) . 
Grand Junction R.R 

Granite , . . 

Granite st 

Lowell R.R. (Freight) 

" (Passenger) 

Maiden* 

Meridian St. (East Boston side) . . . . 

" (Chelsea side) 

Mt. Wasihngton ave. (Boston side) . . 

" " (So. Boston side) 

Neponset 

N.York & N. England R.R. (Boston side) 

" " (S.Boston side) 

North Beacon st 

North Harvard st 

Old Colony R. R 

Prison Point 

Warren 

West Boston (Boston side) 

'• (Cambridge side) .... 
Western ave 



Location. 



Boston to Charlestown 

Charlestown 

Over Fort Point Channel 
Ward 19 to Cambridge 
Boston to E.Cambridge 
Boston to Charlestown 
Charlestown to Chelsea 
East Boston to Chelsea 



Ward 16 

Over Fort Point Channel 
Boston to Charlestown 

Charlestown 

Ward 19 to Cambridge 
Over Fort Point Channel 
Boston to Charlestown 

Ward 19 to Cambridge 
East Bo.ston to Chelsea 
Ward 16 to Milton . . 

South Boston 

Boston to E. Cambridge 

Charlestown to Everett 
East Boston to Chelsea 

Over Fort Point Channel 

Ward 16 to Quincy . . . 
Over Fort Point Channel 

Over South Bay . . 
Ward 19 to Watertown . 
Ward 19 to Cambridge . 
Over Fort Point Channel 
Ward 16 to Quincy . . . 
Charlestown to Camb'dge 
Boston to Charlestown . 
Boston to Cambridge . . 

Ward 19 to Cambridge . 
Ward 19 to Watertown . 



Number 

of 
Openings. 



Width. 



Feet. Inches. 
36 3 



43 
30 
36 
36 
33 
33 
34 
25 
32 
35 
35 
31 
35 
36 
36 
31 
39 
31 
34 
35 
36 
44 
59 
59 
37 
38 
29 
41 
41 
30 
30 
32 
32 
30 
•30 
35 
30 
30 
31 
29 



APPENDIX, 



SPECIAL REPORT ON CHARLESTOWN AND CAM- 
BRIDGE BRIDGES. 



Office of the City Engineer, 

Boston, Jan. 1st, 1875. 

Jos. P. Davis, City Engineer : — 

Sir, — I submit the following report on the Charlestown 
and Cambridge Bridges, in accordance with your request. 

The annexation of Charlestown to Boston did not cause 
any change in the management of the Charles-river and 
Warren Bridges, until July 13, 1874, when the City Council, 
by the passage of a new ordinance, placed them under the 
same control as the other city bridges, and the duties of the 
Commissioners ceased. 

The West Boston and Canal bridges are still in charge of 
Commissioners , for whom I have continued to act as engineer 
during the past year. 

Charles-river Bridge. 

The extensive repairs required on this bridge, which were 
stated in detail in my last year's report, have not as yet been 
made. 

The Commissioners obtained the necessary appropriations , 
but their tenure of office being uncertain, they did not feel 



Appendix. 49 

authorized to commence the work. The bridge is, therefore, 
practically in the same condition as last year, only such re- 
pairs as were needed to keep it in running order having been 
made. 

The easterly end of the draw-pier has been strengthened 
b}^ driving and securely fitting ten new oak bearing and fender 
piles, and the faces of the draw- way have been replanked 
where the old planking was broken or torn off. 

The draw has been disabled once during the year by the 
breaking of one of the main trucks, but, owing to the precau- 
tion of keeping on hand a duplicate truck, travel over the 
bridge was interrupted during only a portion of one day. 

The reconstruction of the decayed portions of the super- 
structure and the other improvements needed should be com- 
menced early in the spring ; for although the bridge cannot 
be called unsafe for travel (the substructure and main por- 
tions of the superstructure being sound) , it is in a discredit- 
able condition for one of the main avenues between the City 
Proper and Charlestown. 

Warren Bridge. 

With the exception of the roadway floor-planking, on a 
portion of the Boston end, which is rotten at the stringer 
bearings, and the fender-guard on the easterly side of the 
Charlestown end, which needs new capping and bracing, this 
bridge is in good condition, and will require only ordinary 
repairs. 

In October two of the main bridge stringers, near the 
Charlestown end, were found to be unsafe. They had evi- 
dently been cracked for some time, as the bridge superin- 
tendent had noticed a settlement at this point ; but, by the 
recent passage over them of teams loaded with large stone 
for the Army and Navy Monument, they had been broken in 
such a manner as to render their renewal immediately nec- 
essary. The bridge was closed to team travel while new 

7 



50 City Document. — No. 19. 

stringers were beiug put in, and advantage was taken of this 
closing to make some repaii's required on other portions of 
the superstructure. 

Canal Bridge. 

During the past year, about 700 feet in length of 
this bridge has been entirely rebuilt, and the remainder 
widened so that it is now, with the exception of the draw, 
of a uniform width of 64 feet from end to end. 

All the decayed portions of the old bridge have been re- 
newed, a new fender-guard and draw-jjier built, the roadway 
paved with small granite blocks, and the sidewalks with 
brick, and both sides of the bridge furnished with gas lamps. 

A new wooden, centre-pivot, counterbalanced draw has 
been constructed, 50 feet in width, and an average length of 
129| feet, and a steam engine and machinery provided for 
moving it off and on, and for pulling vessels through the' 
draw-way. 

Travel over the bridge Avas suspended for five months, 
and the work was completed on the first of October, 1874, at 
acost of $146,598.22. 

The Bridge Commissioners, in their report, say: "The 
thorough and workmanlike manner in which the whole, work 
has been performed is creditable to the several contractors, 
and the Commissioners believe that the bridge and its appur- 
tenances are as well adapted for the exigencies of travel as 
any similar structure leading from the City of Boston." 

West Boston Bridge. 

The wood pavement in the roadway of this bridge is in bad 
condition, and will be replaced with granite blocks in the 
spring. 

The present draw is an unsafe structure, but is soon to be 
removed and a new one substituted of improved construction 



Appendix. 51 

and longer span, as the draw-ways are to be made 36 instead 
of 30 feet in width. In other respects the bridge is in good 
condition. 

Respectfully submitted, 

HENRY M. WIGHTMAN, 

Assistant Oity Engineer. 



SPECIAL REPORT ON FERDINAND-STREET 
BRIDGE. 



Office of City Engineer, City Hall, 

Boston, May 4, 1874. 

Joseph P. Davis, Esq., City Engineer: — 

Sir, — I have examined the bridge on Ferdinand street over 
the Boston & Albany R. R. , and now make the following 
report : — 

The plank covering has been wholly removed from the 
roadway, and enough from one of the sidewalk trusses to 
show its construction. 

No decay has been found in the wood-work, and the iron- 
work is in fair condition. The main trusses show no signs 
of failure that I have discovered. The sidewalk trusseshave 
settled somewhat, and lean outward considerably, but not 
more than I should expect them to do immediately after 
being put in position ; if the bridge be covered with 
plank, I have found no reason why it should not be as strong 
as it has ever been in the past. There are no slight repairs 
that I can suggest which will do much good toward strength- 
enino- it. 

The bridge has always shown great vibration under a 



52 City Document. — No. 19. 

heavy load, and even a very light load is sufficient to deflect 
the floor beams perceptibly. The cause of this is the very 
small depth of the floor beams compared with their span, 
and the manner in which they are attached to the main 
trusses. 

I know of no remedy for this vibration except an entirely 
new set of floor beams, of proper depth, attached to the 
trusses in a proper manner. 

Main Trusses. 

The main trusses are compound structures, one element 
being an arch and tie, the other a truss with parallel flanges 
connected by a web made of concentric circles of bar iron 
riveted to each other and to the arch at all intersections. 
The chords are also connected by vertical tie rods. 

The bridge was designed by Mr. Boles, and built by 
Messrs. G. W. & F. Smith, and was erected in 1863. 

The tie of the arched member has about one-fourth the 
strength of the arch. The only points of attachment to the 
arch are the rivets in the circular bracing. The lower chord 
is attached to the bow in such a manner that it may act as a 
tie, but it is doubtful if the arch adds much strength to the 
truss. 

The parallel chords are about four-tenths of the strength ■ 
usual in bridges of this span, width and height of truss, and 
the bracing is of such character that it is difficult, if not 
impossible, to estimate its strength with certainty ; both 
chords and bracing are of uniform cross-section for the 
whole length of the truss. 

Sidewalk Teusses. 

The sidewalk trusses are wooden structures built of 
4X4 inches, 2X4 inches, and 1-inch sticks, fastened 



AppENDrx. 53 

with cut nails, and put together in such a manner as to 
make any calculations of strength out of the question. 
They have settled 3 or 4 inches below a horizontal line, 
and as much or more from the perpendicular. 

Floor Beams. 

The floor beams are compound structures consisting of 
6-inch I-beams, with a wooden beam 31^ X 6 inches 
on either side, the whole trussed with a 1-inch rod, with two 
struts about 5 inches deep. They are attached to the 
main truss in an unusual manner, resting on one flange of 
one of the tw^o angle irons which make the lower chord, and 
retained there by straps on every third beam, which pass 
through the truss and are fastened to the floor beams of the 
sidewalk ; these straps hold the roadway to the trusses firmly. 

The truss rods of these beams are attached in such a 
manner, and the struts are so short, as probably to add no 
strength to the beam. 

A 6-inch I-beam, 25 feet between bearings, is not very 
stifi" with any load : in this case the ends of the beam are 
firmly attached to the truss, and the truss is shaken from side 
to side by the vibration of the beam. 

The remedy for the vibration is a new set of floor beams. 
The bridge is now 16 feet above the rails of the railroad, so 
that no beam can be put lower than at present. The 
present thickness of the floor of the bridge is insufficient to give 
the proper depth to floor beams for stifluess, consequently anew 
set of floor beams involves the raising of the grade of the 
bridge. If the main trusses could be depended upon, it 
might be possible to build a beam that would answer without 
so doing. In any event it would be necessary to raise the 
trusses in order to attach the floor beams properly. 

I have no doubt that the general reputation of the bridge 
for weakness saves it from many heavy loads, and if a 



54 City Document. — No. 19. 

stronger floor is fiirnishecl, two consequences follow : first, 
heavier loads are to be expected, and, second, the main 
trusses become the weak point in the bridge, instead of the 
floor beams, and an accident to a main truss will be a more 
serious matter than the failure of one or more floor beams. 

The sidewalk trusses are of most extraordinary design, and 
I cannot answer for their strength to any extent whatever. 

In conclusion, I repeat that I know of no slight repairs 
that will do much good toward strengthening the bridge, 
and, in addition, that such repairs as will make it entirely 
safe for public use will amount practically to building a new 
bridge. 

HENEY MANLEY, 

Assistant Engineer in charge of Bridges. 



Charles Harris, Esq., Superintendent of Streets : — 

Dear Sir, — I herewith transmit, with approval of its 
statements, the report of Mr. Manley upon the condition of 
the Ferdinand-street brids^e. 

The design and construction of the parts of this bridge 
are such that it is impossible to estimate what its actual or 
safe strength is ; but it can be shown that it is not capable of 
bearing more than a certain weight, and that weight is much 
less than would be given by a dense crowd. For such a 
load the main trusses are themselves weak, and the floor 
girders are inadequate for the support of a concentrated 
heavy load, such as might be brought upon them by an 
unusually heavily loaded team. That they have not failed 
heretofore is undoubtedly due to the stiffness of the floor 
planks. 

While the brido'e has not that streno-th" which should be 
possessed by one in its situation, it has withstood the travel 
of a number of years without showing signs of failure, or of 



Appendix. 55 

deterioration, except such as the same length of time would 
produce in any structure of the kind ; and if it is not to be 
liable to more severe strains in the future than it has already 
received, I see no reason why it should not remain service- 
able for a number of years longer. 

The wooden trusses on the outside of the sidewalks should 
be replaced, however, by others of stronger form. 

As Mr. Manley remarks, there seems to be no practicable 
wav to strensfthen the main structure without in effect 
rebuilding it. 

JOSEPH P. DAVIS, 

City Engineer. 



SPECIAL REPOET ON COLUMBUS-AVENUE 
BRIDGE. 



Office of City Engineer, City Hall, 

Boston, June 1, 1874. 

Joseph P. Davis, Esq., City Enpineer: — 

SiE, — I have examined Cohlmbus-avenue bridge, over 
the Boston and Albany Railroad, with reference to its ability 
to carry a 20-inch water-main in addition to its present dut}'^, 
and report as follows : — 

The bridge was built in 1865 by James Tetlow, of Chelsea, 
from designs by and under the direction of Clemens Herschel , 
Esq., of Boston, and was paid for by the Boston Water Power 
Company. It cost $17,210.00 and came into the possession of 
the City of Boston, October 28, 1869, when Columbus 
aveiuie was laid out as a highway. 

The main and sidewalk trusses were designed to carry a 



56 City Document. — No. 19. 

load of 40 lbs. per sq. ft. of bridge surface in addition to the 
weight of the bridge, wliicli was taken at 35 lbs. per. sq. ft.', 
and it was intended that this whole weight should sti-ain the 
wrought iron 15,000 lbs. per sq. in. 

The bridge was erected substantially in accordance with 
the design. I have computed the strength of the trusses, and 
my results show that they have the strength intended by the 
design, and but little if any in addition, while the weight of 
the bridge has been greatly increased ; — from 35 to about 
50 lbs. per sq. ft. 

The floor beams are relatively much stronger than the 
trusses. 

The four main trusses are of equal strength, but the two 
next the sidcAvalks of com*se carry less weight than the two 
others. 

ONE MAIN TRUSS IN THE CENTRE, 

Designed to carry . . 1,344 lbs. per running foot. 
Actually carries . . . 896" " " 



Leaving for live load . . 448 " " '* 

Or in lbs. per sq. ft. . . 25 

ONE MAIN TRUSS NEXT SIDEWALK, 

Designed to carry . . 1,344 lbs. per running foot. 
Actually carries . . . 656 " " <' 



Leaving for live load . . 688 " " " 

Or in lbs. per sq. ft. . . 44.4 

A 20-inch pipe full of water weighs 344 lbs. per foot. 

The part to be carried by the main truss will be 277 lbs. 
per running foot, leaving for live load 411 lbs. per running 
foot; or in lbs. per square foot, 26^. Showing that with the 
water-pipe the outside trusses would carry more dead weight 



Appendix. 57 

than those in the centre, but there would still remain a 
slightly greater margin for live load. 

The sidewalk trusses are relatively somewhat stronger 
than the main trusses, and the liooring of the sidewalk is 
stronger than the truss. 

When the bridge was built, one sidewalk truss was blown 
down after, being placed in position, and the lattice web was 
never returned to its perfect shape. 

The northeasterly sidewalk carries a 12-inch water pipe in 
addition to any w^eight heretofore referred to. 

The nifUn roadway has been raised at the centre so as to 
turn the water toward the ends of the span. In so doing an 
amount of lumber has been used equal to a thickness of 12 
inches over the entire surface. This amount of lumber can be 
safely reduced one third, or 10 lbs. per sq. ft., and the same 
results obtained as at present. 

The answer to the question concerning the 20-inch water 
pipe is obvious. No further weight should be put upon the 
bridge on any pretence whatever, and, furthermore, it should 
be relieved of the extra weight of plank (amounting to more 
than twenty tons) that it now carries. 

HENRY MANLEY, 

Assistant Engineer in charge of Bridges. 



Appendix. 57 

than those in the centre, but there would still remain a 
slightly greater margin for live load. 

The sidewalk trusses are relatively somewhat stronger 
than the main trusses, and the flooring of the sidewalk is 
stronger than the truss. 

When the bridge w^as built, one sidewalk truss was blown 
down after being placed in position, and the lattice web was 
never returned to its perfect shape. 

The northeasterly sidewalk carries a 12-inch water pipe in 
addition to any w^eight heretofore referred to. 

The mrtin roadway has been raised at the centre so as to 
turn the water toward the ends of the span. In so doing an 
amount of lumber has been used equal to a thickness of 12 
inches over the entire surface. This amount of lumber can be 
safely reduced one third, or 10 lbs. per sq. ft., and the same 
results obtained as at present. 

The answer to the question concerning the 20-inch w^ater 
pipe is obvious. Xo further weight should be put upon the 
bridge on any pretence whatever, and, furthermore, it should 
be relieved of the extra weight of plank (amounting to more 
than twenty tons) that it now carries. 

HENRY MANLEY, 

Assistant Engineer in charge of Bridges. 



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