Landscape reclamation: a report on research into problems of reclaiming derelict land

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ort on research into problems of reclaiming derelict land
research team of the University of Newcastle upon Tyne

Published by IPC Science and Technology Press Ltd

LANDSCAPE
RECLAMATION

a report on research into problems of
reclaiming derelict land

by a research team of the University of
Newcastle upon Tyne

Volume 1

SBN for complete set of two volumes: 902852 06 X
SBN for this volume: 902852 03 5

Published by IPC Science and Technology Press Ltd,
IPC House, 32 High Street, Guildford, Surrey, England.

Printed in England by Kingprint Ltd, Orchard Road, Richmond, Surrey.

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Foreword
Introduction
Chapter 1

Chapter 2

Chapter 3

Chapter 4

Chapter 5

Chapter 6

Chapter 7

Chapter 8

Chapter 9

Chapter 10

Chapter 11

Chapter 12

Chapter 13

Contents

by the Right Honourable Peter Walker, M.B.E., M.P.
Secretary of State for the Environment

Landscape reclamation and the region

Previous techniques of reclamation
based on the work of C.J. Vyle

Research sites
by M.F. Downing

Landform design
by M.F. Downing

Earthworks: outline of metnods used within the project
by M.F. Downing

Special problems
based on the work of M.F. Downing and C.J. Vyle

Land drainage
by M.F. Downing

Soil-forming materials—their nature and assessment
by G.P. Doubleday

Botanical studies of natural and planted vegetation on
colliery spoil heaps
by J.A. Richardson, B.K. Shenton and B.J. Dicker

Practical techniques for establishing vegetation on derelict
land
by C.J. Vyle

Contract procedure
by |.S. Clarke

Estimating and cost control
by 1.S. Clark

Visual assessment of reclaimed landscape
based on the work of J.J. Ffennel and others

Foreword

he Right Honourable Peter Walker, M.B.E., M.P., Secretary of

State for the Environment

| welcome the opportunity afforded by this Foreword of stressing the
importance which | attach to the clearance of derelict land.

The scars left behind by industrial development of the past, the
abandoned waste heaps, disused excavations and derelict installations and
buildings no longer needed by industry, are an affront to our concept of
an acceptable environment in the 1970s. The clearance of this

dereliction can play a significant role in improving the environment in both
a rural and an urban setting.

More reclamation than ever is now being undertaken; local authorities are
being asked for an all-out effort and there are good prospects that the
greater part of the derelict land will be cleared away within the decade.
But, of course, reclamation is not only a matter of allocating the necessary
resources. We need to know how to make the best use of our resources, to
examine techniques and to improve on them.

| am therefore grateful for the growing volume and variety of research, of
which this Report forms part, which will have great practical benefits for
the work of reclamation.

eet:

Peter Walker

Introduction

The problem of derelict landscape is an important issue
facing the nation. Britain, already short of land, will be in
a worse situation as the population increases; it is
therefore a matter of necessity, and many would say of
urgency, for the majority of the 37,490 ha (93,920
acres) of land now officially classed as derelict, to be
restored to a state of good health and service in the

total landscape and for the community. Because of the
large area of derelict land and vast tracts which escape
the official classification, the cost of reclamation will be
considerable. If the reclamation work is allowed to
proceed without a sure basis of research into the design
and planning concepts, into the fundamental problems of
soil formation and plant survival, and into the many
techniques which will need to be worked out, this cost
will be excessive.

There are, of course, many kinds of landscape dereliction,
such as derelict coal mines, gravel excavations and old
industrial buildings. Each kind of dereliction is likely to
require certain techniques in reclamation which are
peculiar to its own particular problems. No single research
programme can hope to provide all the answers, but an
extensive one will be of general use in that it can
establish principles as well as techniques. In the Landscape
Reclamation Research Project of the University of
Newcastle upon Tyne, we have sought to avoid going over
ground already covered in previous studies, and this can
be seen both in the work relating to the design principles
and, at the other end of the scale, in the work on
techniques for specific operations and circumstances.

Important work has been undertaken in the period since
the Second World War by some planning authorities faced
with derelict land in their areas, and also by specialists
working on problems like the establishment of trees on
waste heaps. Among several problems which have been
studied in the University Research Project was the central
one of the design of landscape reclamation schemes in
such a manner that the natural processes, which will
eventually bring about a balance between drainage,
erosion and vegetation cover, can be speeded up. Also,
the objective was to achieve a new and healthy land-
scape without tying the planning authorities’ hands to a
particular land use.

The University was particularly fortunate in having the
opportunity to carry out much of the research work in
what may be termed ‘outdoor laboratories’. These were
eight selected areas with varying kinds of dereliction, and

it was possible to plan the reclamation works for these
areas with the additional advantages of including
experimental techniques in specific places. In the chapters
that follow, these techniques are described with the
results achieved up to the present time. The work of
assessment will, however, continue for many years and
will form a part of a related research project into the
problems of husbanding reclaimed landscapes beyond the
initial stage. This latter project has been made possible by

a generous grant to the University from the Natural
Environment Research Council, and the results will be
published in a second volume.

The University’s interest is in the whole problem of
changing derelict landscapes into healthy landscapes,
although, within this major interest, the numerous

special aspects also claimed appropriate attention.
Consequently, the task of setting-up the research frame-
work fell to the Landscape Design staff but the
Departments of Botany and Soil Science have been
essential to the work and have been most closely
involved at all stages. Quite apart from the objectives of
the research, a clear demonstration has been given that
several disciplines in a University can make a contribution
far outweighing that which would have been given by a
single discipline.

Those of us who have worked on the project readily
acknowledge the guidelines that have been given by many
persons and sources of reference in various countries. In
particular, the study tours made by some of the research
staff to the excellent landscape reclamation work in the
Ruhr, and to some of the earlier work carried out by the
County Planning Department of Lancashire, proved
extremely valuable. In all of these contacts, examples of
failures were given as readily as the demonstration of
success. We would wish to make a special point of the
important work of the Department of Botany who carried
out the survey and analysis of both naturally occurring
and artificially planted vegetation. This basic line of
approach has always been associated with the discipline of
Landscape Design in the University of Newcastle upon
Tyne as an aid to deciding upon the types of vegetation
cover and the particular tree, shrub, and grass species to
be used. The survey, and in fact most of the work
described in the ensuing chapters, has been written up at
much greater length in the series of interim reports which
have followed one another in quick succession during the
course of the research work.

A particular feature of the project has been the work of
its Steering Committee, which met at monthly intervals
for the first three years, and every other month

subsequently. The membership is listed in detail elsewhere,

but the Committee certainly gained much of its skill in
guidance, advice and criticism from those members
outside the University, including in the later stages
persons concerned in the River Tyne Steep Slopes
Research Project. The Steering Committee also served in
some measure in place of a Director of the Project, this
being a more appropriate arrangement in view of the
involvement of several Departments of the University.
The responsibility for the various parts of the research
and for the material and views expressed in the several
Chapters thus rests with the Authors, although in most
eases, each Author has necessarily drawn upon the work
and experience of his fellows in the Project.

The scale of work can in part be measured by the fact
that six research workers have been involved on a full
time basis, five members of the teaching staff have given
much time voluntarily, and valuable assistance came from
the employment of students during some vacations.
Again, the names of all concerned are listed elsewhere.

The importance of landscape reclamation as a national
objective, and of the need for it to be studied from all
points of view, was discussed in a meeting called
together in 1963 by the then Vice Chancellor of the
University, Dr. C.I-C. Bosanquet, supported by a
representative of the Ministry of Housing & Local
Government and by the County Planning Officers of
Durham and Northumberland and the Planning Officer of
the City of Newcastle upon Tyne. Also present were
representatives of University Departments likely to be
concerned. Subsequently, the financial side of the work
was made possible by the ready cooperation of the
Ministry and the planning authorities, who were able to
make available funds within the grant structure for the
reclamation of derelict land.

Finally, every credit is due to the members of the
research team, including several members of the
University Teaching Staff who contributed a great deal in
a directive capacity. To Miss Jennifer Ffennell, a member
of the Research Staff who also undertook the initial task
of gathering together the Authors’ manuscripts for
publication, Miss Jill Pagan who completed it and to
Miss Anne Stokoe, who from 1965 to 1970 served as
Secretary to the project, all of those concerned owe a
special debt.

Steering Committee

.S.Clark, Messrs. Douglas Macara/Groves/ Associates,
Quantity Surveyors, Newcastle upon Tyne.

The County Planning Officer for Durham represented by
R.Briggs, Reclamation Officer.

The Engineer & Surveyor, Easington Rural District
Council, represented by the late E.Crompton,
Senior Assistant Engineer, W.McCrickard,
Reclamation Officer, and W.Scanlan, Planning
Officer.

The Borough Planner and Engineer, Gateshead,
represented by A.F.Barber.

S.Hall (since retired), Surveyor, Crook & Willington Urban
District Council.

W.T.Kailofer, Engineer & Surveyor, Newburn Urban
District Council, also represented by J.Grant.

J.A.Mann, Director of Parks & Cemeteries Department,
Newcastle upon Tyne.

Ministry of Housing and Local Government, represented
by R.U.Harper until 1968, and subsequently by
J.W.Dickson.

R.Morton, Surveyor, Felling Urban District Council, also
represented by R.Whyte.

The City Planning Officer for Newcastle upon Tyne,
represented by Miss E.L.Elliott, Landscape Architect.

The County Planning Officer for Northumberland,
represented by F.E.Kerry, Reclamation Officer, and
S.Manchee.

The Borough Engineer & Surveyor, County Borough of
South Shields, represented by K.Smith.

The Borough Surveyor, County Borough of Tynemouth,
represented by W.A.Charlton and M.Preston.

Also certain other people who have attended from time to
time, and the following members of the University Staff:

B. Hackett: Professor of Landscape Architecture.

M.F.Downing: Lecturer in Landscape Design.

Miss J.Ffennell: Research Associate in Landscape Design.

C.J.Vyle: Senior Research Associate in Landscape
Design, assisted by J.Fuchs for one year.

Miss J.Pagan: Research Associate in Landscape Design.

P.W.Arnold: Professor of Soil Science.

G.P.Doubleday: Senior Research Associate in Soil
Science.

Patricia Hill: Technician in Soil Science.

Angela Bruce: Technician in Soil Science.

Dr.J.A.Richardson: Senior Lecturer in Botany.
Dr.A.W.Davison: Lecturer in Botany.
Dr.O.L.Gilbert: Senior Demonstrator in Botany.
R.Dicker: Research Associate

Students working during Vacation

Miss\ S.Lewis (Botany )

Miss S.McDonald (Botany)

D.F Hardy (Botany)

B.Shenton (Botany)

D.J.Moffatt (Soil Science)

A.H.Cosens (Zoology )

C.Hindmarch (Landscape Design)
P.H.Goodchild (Landscape Design)

Miss A.Stokoe: Secretary (to October 1970)
Mrs H.Cox: Secretary (from October 1970)

Note: in connection with further work to be published in
Volume 2, the following have been involved in the
Project:

University Staff
Dr.M.L.Luff (Agricultural Zoology )
Dr.B.J.Selman (Agricultural Zoology )

Students working during Vacation

B.R.Hutson (Agricultural Zoology)
M.I.Hinke (Agricultural Zoology)

Chapter 1 Landscape reclamation and the

region

1.1. Introduction

Preliminary investigations into the problems of landscape
reclamation revealed the fact that the selection of sites
on earlier programmes had been made in most cases on
an ad hoc basis, and the evidence was that this situation
still prevailed. The reasons included the availability of
derelict land for purchase, the low cost likely to be
involved on a project, and the demand fora particular
land use in the area. Whilst the immediacy of these
reasons must be acknowledged, the element of
convenience which attaches to them is hardly appropriate
to the vast expenditure now forecast over the next ten
years or so. Thus, a study was made of the way a land-
Scape reclamation policy could be related to the landscape
pattern of the region in which derelict land occurs. It was
not considered that a study of land use and derelict land
from a regional point of view was part of the brief,
although such a study is very proper to the work of a
planning authority.

The study which was undertaken brought out the need

for reclamation schemes to be so designed that they fit
into the ecology of the regional landscape - in other words
they should restore the continuity of the landscape, and
once again should become an integral part of the surface
drainage and the soil and vegetation patterns, instead of
constituting a landscape in isolation.

1.2 Regional landscape plans

Among those policies reviewed under which the
objective of landscape continuity might be achieved, the
establishment of a landscape planning framework was
considered to be the most appropriate. This conclusion
was tested by a study made by members of the research
team on landscape reclamation on the Continent which
had been carried out under landscape planning policies;
reference is made to this study later. As a result of our
findings, and bearing in mind the mediocre results in the
past of many schemes prepared in isolation, it is
recommended that analyses of the physiology and ecology
of the regional landscape in which dereliction occurs,
should be made available to individual authorities and
designers of projects in order that these projects may
accord with the basic landscape pattern disclosed by the
analyses. These analyses could be made on a regional
basis through the appropriate Ministry, or on a county
basis through the planning authorities.

1.2.1 Planning framework

The importance of the above recommendation is brought
out by some definitions of landscape planning, of which
three examples are given.

(a) “The substitution of the term landscape-planning for
land planning makes a deliberate widening of the
conception of planning to include appearance as

well as use, pleasure as well as fertility, and the
whole complex organic fabric of life, as well as
man’s immediate needs” (Crowe in I.U.C.N. 1967).

(b) “Within the concept of these landscape plans (for
the Dutch countryside), the different aspects of
landscape planning are taken into account. This
involves preservation of valuable landscape features
as well as the creation of new elements and the
integration of a consciously designed new land-
scape in the process of a multi-purpose land
reconstruction” (Benthem in I.U.C.N. 1967)

(c) “The objective of landscape planning is to ensure
that landscape changes continue to provide habitat
conditions that will accommodate the various forms
of life, either in the existing pattern or, if the
habitat conditions are changed, in a new pattern.
Its definition embraces the need to reconcile and
incorporate competing land uses in the landscape”
(Hackett in I1.U.C.N. 1967).

1.2.2 Investigations

Among several detailed investigations made in the study
of the relationship of a landscape reclamation policy to
the landscape pattern of the region, three examples are
summarised as follows:

(a) Jnternational resolutions Several international
resolutions concerned with the environment
supported the regional approach of landscape
planning. The Green Charter of Mainau of 1961
stated that the creation of a sound landscape, which
could support residential and recreational area and
could sustain agriculture and industry, was
indispensable. The UNESCO resolution of 1962 saw
landscapes and sites as important factors in the
economic and social life of countries. The Council
of Europe in 1964 passed a resolution on regional
planning and the conservation of nature and land-
scape.

(b) Dutch landscape planning The fact that over 50%
of the land of Holland is subject to planned land-
scape development clearly indicated that enquiries
should be made whether this had led to better
results socially, economically and aesthetically than
under other systems of development control else-
where. Also, the fact that some parts of the area
were lands newly-won from the sea was of
particular interest to our research into newly-won
landscape from derelict land. The answers to
enquiries and the research team’s own observation
of several areas in Holland confirmed the generally
held view that the new and the modified landscapes
based upon landscape plans have been successful.

(c) West Germany The reclamation of industrial

dereliction in the Cologne brown coalfield and in
the Ruhr has been widely praised. An investigation

was made by the research team of the particular
techniques used (see Chapter 2). Also examined was
the manner in which the proposals of the mining
companies must be related to regional plans which,
in turn, must be worked out in association with
landscape plans. An important point is that these
landscape plans are based upon the structure of
the landscape and its ecology. In the results
observed by the research team, the value of
planning in this way was abundantly clear in the
upgraded environment of new open spaces, forest
areas, and the riparian landscape.

1.3 The situation in Britain

It will have been noted that considerable emphasis is
placed upon the need for landscape reclamation

taking place in accordance with regional plans which
have a strong landscape planning component. It is not
surprising, therefore, that the situation in Britain,

where no provision comparable with the Dutch and

West German examples is made, should be the subject for
comment and recommendations.

The latest figures available for the extent of dereliction
(which does not include areas which many people would
consider derelict) are given in the following table:

Derelict land - England and Wales in hectares (acres)

Derelict land Reclaimed land Reclamation

planned
1964 39,636 (99,091) 992 (2,481)
1965 43,006 (107,515) 957 (2,393) 1,579 (3,947)
1966 44,435 (111,088) 737 (1,842) 2,117 (5,293)
1967 44,971(112,428) 747 (1,867) 2,010 (5,026)
1968 45,184 (112,961) 1,078 (2,695) 2,332 (5,829)

No official figures are available for Scotland, but one
estimate rates the figure at about 6,800 ha (17,000 acres)
of derelict land.

A significant point is that to date, completed reclamation
projects are not bringing down the total area of dereliction,
because new dereliction is outpacing reclamation. In view
of the Government’s declared policy to clear dereliction
within ten years, the programme at all levels from the
National Government, through local Government, to the
design team, and the contractors (who translate policy into
projects) must be speeded up. As a first step, it is
recommended that a study should be made, on the one
hand, of the number of design and supervising staff, and
supporting experts and, on the other hand, of the number
of Ministry (now Department of the Environment) officials
for approval and advisory purposes, who would be needed
to make a substantial annual reduction to the total area of
dereliction. Also, that ways and means of speeding up land
acquisition should be studied, as this was found to
constitute a particular difficulty in holding up projects. The
experience gained from the several sites used for the
research showed no lack of interest from contractors
willing to undertake projects.

The recent setting up by the Ministry of a derelict land
reclamation group to provide central advice and information
and to take a continuous overall view of the dereliction
problem is welcome. But it is stressed most strongly that the
gap will not be filled without establishing a sufficient

number of designers, quantity surveyors, experts in Soil
Science and other disciplines at the local level, backed by
Ministry officials who recommend approval of suitable
schemes.

1.4 Industrial waste and dereliction

During the course of the research a great deal of evidence
was collected and studied on the restoration of landscape
health and fertility under landscape planning policies in
areas of dereliction in other countries. In addition to the
particular matter of reclaiming derelict sites, the
possibility of controlling and perhaps preventing, future
dereliction was examined. It was concluded that if the
planning for, and the control of, industry took place within
landscape planning considerations grafted on to the
existing statutory planning provisions, the problem of
derelict land would be diminished for future generations.

A particular problem is that if the planning conditions

on the formation of new waste heaps or coal mines are too
stringent, this may lead to the closure of a coal mine which
is operating close to the margin of profit and loss.
Nevertheless, when it is realised that the cost of subsequent
reclamation of a waste heap involving earthmoving was in
1970 in excess of £3,000 per hectare (£1,250 per acre), it
is not unrealistic to take steps in the first place against the
need for a subsequent expensive reclamation scheme. One
possibility is to ensure that, when tipping, the less toxic
materials are placed on the surface; such a scheme may then
require a less intensive use of ameliorants in after
management.

A landscape plan for the dereliction problems of a region
could include proposals for the economic use of materials.
Forexample, colliery waste heaps could be assessed for:

(a) Those minerals which, if removed, would reduce the
fire risk.

(b) The coal content which, if over 15%, can often be
economically salvaged.

(c) The red shale content which is often a suitable source
of foundation material for nearby road projects (some
black shale is also accepted for this purpose).

(d) Other materials, like brick rubble, slurry and coke,
may have a salvage value if present in sufficient
quantity and adequate quality.

However, in order for the above proposals to be effective, it
would be necessary to bring them under planning control.

1.5 Definitions

In the course of the research work, the difficulty arising
from the definition of derelict land which is acceptable for
grant purposes became clear. The official definition used by
the Ministry for grant award is “land which is so damaged
by industrial or other development that it is incapable of
beneficial use without treatment”. It has been widely
suggested that this definition should be studied afresh,
clarified and broadened because it does not appear to

cover all the categories mentioned in the Acts, that is
derelict, neglected and unsightly land. As an example of the
difficulty, it can be argued that some sites, conforming with
the definition, would make excellent adventure playgrounds
with very little cost, and thus would be capable of fulfilling
a “beneficial use”; such a site would not rank as derelict
and no grant would be awarded for its visual improvement.

Another example is the vast area of derelict landscape
lying in small lots which once had some agricultural or
other use, doubtless too small or badly located to attract
the normal developer. (Collins and Bush, 1969)

The wisdom of the Ministry decision allowing land
adjoining derelict land to be incorporated into a reclamation
scheme in order to achieve a better functional and visual
solution was fully supported by the preliminary design
studies made for the Roddymoor experimental site.
Without this admissible extension of the narrow inter-
pretation of derelict land, the overall result on many sites
could be diminished. A convincing case however must be
made for the inclusion of adjoining land.

A difficulty that became evident in discussion with
Ministry officials was the degree to which the reclamation
works can be taken and how far they can provide for the
use of the land after reclamation. The present basis for
decisions is contained in the explanatory memorandum
on grants (MOHLG 1967) as follows:

(a) expenditure incurred in the acquisition of approved
land, including legal and professional expenses
properly payable in connection with the acquisition
of the land, and the expenses of investigation or

survey fees to determine its suitability for reclamation,

and,

(b) expenditure, including professional fees and
administration expenses properly chargeable to loan,
incurred in carrying out approved works of
reclamation. The works which will be approved will
depend on the scheme. Provided that the Minister is
satisfied that they are required primarily for the
purpose of reclamation the following works under-
taken on approved land will be eligible:

(i) demolition and removal of unwanted buildings and
works;

(ii) earth moving for the purpose of levelling, filling,
spreading and grading;

(iii) land drainage essential to the works of reclamation;

(iv) the importing and spreading of top soil and grassing
for amenity schemes;

(v) tree or shrub planting where required for the
purpose of soil conservation, or consolidation, or
where planting is satisfactory and more economical
than other methods of treatment.

The reference to tree or shrub planting ((b) (v) above)
supports experience on the first two experimental sites
set up for research purposes - Northbourne Park and
Egerton Gardens. On both these sites, extensive shrub
planting on steep banks was recommended as providing
the best solution under the conditions prevailing, but
some months of discussion, supported by visual evidence,
took place before this solution was accepted for grant
purposes. The strict interpretation of works eligible for
grant under (b) (v) above has been widened to include tree
planting where there is a lack of trees in the locality or
where it would upgrade a poor environment.

Although many local authorities would welcome the
extension of the works eligible for grant to include
additional works related to a use of the land, the first task

is to restore the health and fertility of the landscape over
large areas of derelict land, instead of spending the same
amount of money on a lesser number of projects taken to

a state suitable for uses like public parks and fully-developed

agricultural land. Some preliminary uses, like silage
cropping and grazing are, of course, part of the works for
restoring the health and fertility of the landscape.

1.6 Regional considerations

The eight derelict sites in the North East made available
for research (two further sites were studied in some detail)
were necessarily selected as far as possible to provide the
greatest diversity of research problems. Also, wherever
possible, the part that a reclaimed site could play in the
region or locality was considered. In the early days of the
research work, representatives of regional sport and
recreational interests, of mineral salvage concerns, and of
conservation bodies attended meetings of the Steering
Committee and each scheme was commented upon in the
light of these wider interests. It will be noted in Chapter 10
that a survey of over 200 sites was made in the North East to
discern any significant pattern of naturally occuring
vegetation on derelict sites. At the Big Waters site, in
particular, the wildlife, boating and fishing interests were
studied to find ways of providing for them on the same
area as a result of strong demand from all three. Finally,
for each of the sites, the proposals and experiments took
account of the physiology and ecology of the

surrounding landscape.

1.7 Conclusions

In the light of the brief for the research concentrating on
the design and technical problems of landscape reclamation,
the conclusions on the investigations made into the wider
aspects must necessarily be few and general in character.
Nevertheless, the solution of the broader planning decisions
may well be the solution of the nation’s dereliction
problems:

(a) There is a need for reclamation schemes to relate
specifically to the landscape of the region and
locality, and this can best be achieved through
incorporating landscape planning into statutory
planning.

(b) Despite international resolutions and the Continental
examples, there is little real evidence of landscape
planning in Britain - if there was, the dereliction
problem could be tackled more satisfactorily.

(c) The weak link in the nation’s reclamation programme
is the failure to set up an adequate establishment of
design teams to initiate and carry through the
technical and legal aspects of landscape reclamation
schemes. The need for expanding education
facilities must be pointed out in this respect.

(d) The definition of derelict land requires amendment
and extension to damaged and disfigured landscape in
all parts of the country, with emphasis on the
restoration of health and fertility to the landscape
rather than on immediate uses.

References

Barnard, E. (1965) Developing the rural landscape to
balance the increasing urbanisation of countries.
‘A landscape plan for recreation areas’. JUCN
Landscape Planning Committee Symposium.
Newcastle upon Tyne.

Benthem, RJ. (1961) Landscape planning in rural
development. The Way d4head. Vol. X number 1.

Civic Trust (1964) Derelict Land; a study of industrial
dereliction and how it may be redeemed.
London.

Collins, W.G. and Bush, P.W. (1969) The definition and
classification of derelict land. Journ. Town
Planning Institute. Vol. 55, No. 3

Council of Europe (1964) European Conference of
Local Authorities, Resolution on Regional
Planning and the Conservation of Nature and
Landscape.

The Countryside in 1970 Study Group 12. Reclamation
and Clearance of Derelict Land. Royal Society of
Arts, The Nature Conservancy, The Council of
Nature. Garden City Press.

Downing, M.F. (1967) Reclamation of derelict landscape.
Planning Outlook, new series Vol. 3. pp. 38-52.

Downing, M.F. and Vyle, C.J. (1966) Landscape
Reclamation Research Project. University of
Newcastle upon Tyne. Journ. Inst. Land. Arch.
London.

Durham County Council (1966) Formal application for
approval of grant. Industrial Development Act 1960,
Section 20, Rehabilitation of sites in Development
Areas.

Durham County Council (1966) Explanatory note.

Green Charter of Mainau.(1961) Griine Charta von der
Mainau.

Hackett, B. (1964) The Landscape content of the plan.
Planning Outlook. Vol. V1. No. 2. pp. 5-21.

Hackett, B. (1967) Landscape analysis of urban fringe
areas. Landscape Architecture, USA.

10

Institute of Landscape Architects (1967) Techniques of
Landscape Architecture. Chapter 3. Site Survey
and Appreciation, Heinemann Ltd.

International Union for Conservation of Nature and
Natural Resources. (IUCN) (1967) Part IL. Section 1.
The significance of planned landscape development
in thechanging conditions of human existence.
Section 2. Methodology and experience in landscape
planning to meet the need of environmental changes.
IUCN Pubs. new series No. 8.

Joint Consultative as to Regional Planning, technical
sub-committee of planning officers. Derelict land in
the North-East.

Laurie, I.C. (1965) Tyne Landscape. Consultant’s Report.

Ministry of Housing and Local Government (1967)
Explanatory memorandum on grants for the
reclamation of derelict, neglected or unsghtly land
under the Industrial Development Act 1966 and
the Local Government Act 1966.

Oxenham, J.F. (1967) Land Reclamation. Town Planning
Institute Journal. Vol. 53, No. 8. pp. 344-347.

Riddell and Downing (Eds) (1967) Papers on landscape
planning, survey and appreciation, Institute of
Landscape Architects Conference. Planning Outlook
New Series. Vol. IV.

UNESCO (1962) Recommendations concerning the
safeguarding of the beauty and character of
Landscapes and sites.

Vyle, C.J. (1968) Landscape planning approach to land
reclamation. J. Inst. Parks Admin. Vol. 33 No. |
pp. 22-24 and Vol. 33 No. 2 pp. 37-42.

Vyle, C.J. and Degenhardt, C.C. (Eds) (1967) The
evolution of the Natural Landscape in the Corbridge
Area of Northumberland. Planning Outlook. Vol. 3
pp. 53-70

Chapter 2 Previous techniques of

reclamation

based on the work of C.J.Vyle

2.1 The study by Knabe of reclamation in various
countries

An important review of completed reclamation projects in
various countries was made by Knabe for the period 1950
to 1964, and covered the following matters:

2.1.1 Types of waste land

These can result from:

(a) Change by earthmoving equipment.

(b) Cover by waste materials.

(c) Disturbance in relation to ground water and drainage.
(d) Effects of air pollution.

(e) Dereliction as a result of an industrial neighbourhood.

2.1.2 Reasons for the absence of vegetation or the
development of an adequate cover

Fresh disturbance by machines, lack of soil, stony soils,

rate of weathering, absence of humus, value of other
organic materials, nutrient deficiency, extreme soil reaction,
toxic ingredients, adverse physical properties of waste,
rising ground water table, erosion and air pollution.

2.1.3 Aims of reclamation

(a) Return to economic use by agriculture and forestry.
(b) Development of facilities for outdoor recreation.
(c) Protection against wind and water erosion.

(d) Increased amenity of the area.

(e) Housing developments.

(f) Planning of new industry.

(g) Road building etc.

2.1.4 Lines of approach

(a) After the waste land has been left by industry, some
authorities accepted the site conditions as they were
and planted the area with pioneer plants of low
requirements.

(b) Some improved poor sites by reshaping the contours
and by adding soil amending substances before or
after planting.

(c) Others planned the future land use before disposing
of the waste, and followed this by restoring fertility
to the site.

2.1.5 Examples of reclamation

The principle examples cited by Knabe were: afforestation
in the coal regions of USA; the Danish ‘Desert Arboretum’
on lignite spoil banks; planting trials on tin and gold mine
waste and on pulverised fuel ash; topsoil management;
reclamation schemes in Lancashire, United Kingdom; land
reclamation in Germany; amelioration of toxic
carbonaceous shale; advanced planning of land use in the
brown coal area of Cologne; and others,

2.2 Grass establishment on colliery shale
in Lancashire

Three members of the University research team - Doubleday,
Downing and Vyle - undertook a study tour in 1966 of
some representative reclamation schemes in Lancashire.
The Project is indebted to the Lancashire County Planning
Department for putting at its disposal their early
experience, and enabling others to benefit from the
examples of success and failure that were met in the course
of the work. The sites visited were Bickershaw Reservoir,
Whalley’s Basin, Pennington Green, Bryn Hall and
Bamfurlong and Marsh Houses, and the report (Downing
1966) is summarised below with respect to grading and
grassing, and gives conclusions on alternative treatments

2.2.1 Bickershaw Reservoir Site, Abram

A detailed description of this site and the work undertaken
is given as an example of the study made by the team. This
is the oldest reclamation site undertaken by Lancashire
County Council incorporating grading of the surface to
achieve a useable piece of land (Fig. 2.1), and contrasts
with earlier schemes which were concerned with planting
unaltered pit heaps (Fig. 2.2). It has also been carefully
documented by Coates (1960). The site is 4.05 ha (10 acres)
and comprised low heaps, mostly black shale with some
clinker and ash. The shale was derived from a colliery
which closed in the mid 1920's. The initial reclamation was
carried out in 1954.

(a) Earthmoving. A D6 tractor with dozer blade and a
4.6m3 (6 yd3) scraper attached was used for the main
work, together with a D4 tractor with dozer blade
for final grading. Depth of fill of colliery shale was
from 0.3m-6.1m (1ft-20ft). For the ground and

Fig 2.1 An early example of reclamation with grading to
produce a useable piece of land at the Bickershaw Reservoir
site in Lancashire (Courtesy of Lancashire County Planning
Department).

11

surface preparation a 1.5m (Sft) rotavator set to work (c) Seeding. The optimum seeding rate appeared to be in
at a depth of 100mm (4in) was found to be the best the region of 73kg/ha (65lb per acre), but this varied
»nt for major cultivation. One chain harrowing according to the fertility of the spoil. The grasses
was carried out before seeding and two after, and a and clovers giving the best results (and which were
lat roll was also used agriculturally useful) were in order of preference:
(b) Grass seeding. The seed was hand broadcast at
SOkg/ha (45lb per acre) and contained Grasses Clover
12% S.22 Italian Ryegrass S.143 Cocksfoot S.151 Early Red Clover
14% S.23 Perennial Ryegrass S.53 Meadow Fescue S.100 White Clover
50% S.143 Cocksfoot S.59 Creeping Red Fescue
8% S.48 Timothy §.23 Perennial Rye Grass
10% S.59 Creeping Red Fescue S.48 Timothy
GS-15 Early sso Serdeie The best cover had been obtained by hand sowing or
It was suggested by Coates ( 1960) that the lowest rate fiddle’, making two passes, the second at right
on shale should be 45kg/ha (40lb per acre), that angles to the first. If the area was large, then a seed
S6kgha (50lb per acre) would give better cover, and barrow would have to be used; sowing was again made
the optimum cover on bare shale ofa level nature evinced above,
would be around 72 kg/ha (65lb per acre).
(d) Manuring. The application of an organic fertiliser
. prior to cultivation should be looked upon as a
2.2.2 Vegetation on colliery shale prime requirement. Any non toxic organic matter
As a result of their experience on a number of sites, the would be useful, and the fact that it might be low
Lancashire County Planning Department suggested various in available plant foods was very much a secondary
principles and methods for establishing vegetation on consideration. The important factor was to choose
colliery shale (Coates 1960). These are summarised: a substance which, by physically improving the
(a) Chemical testing. Prior to site work, the site should eat would make it more'suitable for the promoniag
be tested for toxic elements using indicator plants of growth.
and laboratory tests. Chemical analysis should also The main attributes of organic matter in the spoil
be undertaken to ascertain whether the amount of were considered to be:
sulphate would in due course reach toxic levels. (i) Better control of air and water.
(b) Cultivations. The best implements were found to be: (i) PS NON physics seucnne oes a
(i) Rotovator, 2-3 passes at7Smm-100mm (3in-tin) creation of adhesion between particles resulting
setting. 5 a the binding together of the spoil.
(ii) Subsoiler. Very useful to aerate the shale and (iii) boagneeetat of soil bacteria.
break up hard impervious layers formed (iv) Plant foods.
naturally or through the use of heavy earth The rate of application should be as high as
moving equipment. 450mm (18in) was found economically feasible and would depend on the
to be a satisfactory depth. substance chosen, for instance sewage sludge should
(iii) Chain Harrows. Effectively create a top tilth be applied at a heavier rate than farm-yard manure as
to receive theseed and the covering of the the latterhad a more pronounced physical effect.
seed. No application should be at a rate lower than
25 tonnes/ha (10 tons per acre), 50 tonnes/ha
(20 tons per acre) being a more suitable dressing.
It should be applied to the land before cultivations
are begun.
(e) Fertilisers. During the period up to the publication
of the results of the Lancashire County Planning
Department’s experience, it was considered that most
plants grown on shale suffered from potash deficiency
to some extent. A compound fertiliser was therefore
used which had a fairly high potash content. A
dressing of nitrochalk was made at the same time and
the following rates were suggested:
Compound (high potash) 376 kg/ha (3 cwt/acre)
i.e. 10:10:18 units/cwt
Nitrochalk 188 kg/ha (1% cwt/acre)
ie. 21%N.
These should be applied together immediately prior
to seeding.
:. (f) Lime. It was indicated that as colliery waste

Fig 2.2 The Woodshaw Pit spoil heap in Lancashire is an
early example of a reclamation technique involving planting
on unaltered pit heaps (Courtesy of Lancashire County
Planning Department).

weathered it became gradually acidic, and toxic
reactions had been obtained on the surface of heaps
which had been exposed to the elements for over
thirty years. Newly dug spoils might be neutral, but

12

this condition did not last long. When the pH reaction

is not lower than 4.5, 7.5 tonnes/ha (3 tons/acre) of

ground limestone will usually remedy the acidity
The lime should be applied prior to the organic
matter.

2.2.3 Development of techniques in Lancashire
since 1960

Since 1960 a standard form of specification has been
evolved in Lancashire for the ground and surface
preparation and seeding. Also, the incorporation of a
twelve month maintenance fertiliser and cutting period
helps to establish the sward

At Bryn Hall, for example, which was reclaimed over the
period 1961-5, the following specification was used

(a) Ground and surface preparation - This is described

in the Bill of Quantities thus

(i) Lime spreading (see under lime).

(ii) Remove all brick stones, wood and metal and
other materials likely to obstruct cultivations

(iii) Cultivate (Heavy) i.e. 1SOmm (6in)

(iv) Disc (Heavy).

(v) Disc (Light).

(vi) Distribute fertiliser (Spinner Broadcaster)

(vii) Cambridge roll.

(viii) Broadcast grass seed at 39.5 kg/ha (35lb per
acre).

(ix) Harrow roll.

(b) 1/2 month maintenance period
(x) Cut grass with forage harvester (twice).
(xi) Broadcast fertiliser.

~~

(c) Lime and fert r treatmer D>
id | (4 )
tone 4 CaO
(d) Fertiliser. Seedbed 628 kg/ha ( wt/acre)
13:13:20 unit wit tertiliser. Maintenar
376 kg/ha (3 cwt/acre) of a 13:1 0 unit
fertiliser
The units given in the text are percentage
percentage P50 and K>0
(e¢) Grass seed. Supply and deliver the following mixtur
kg/ha = (Ib/acre)
10 6 NZ Certified Mother Perennia
Ryegra
7.0 6 S23 Perennial Ryegra
4.6 4 $43 Cockstoot
4.6 4 S48 Timothy
23 2 S50 Timothy
4.6 4 S215 Meadow Fescue
7.0 6 S53 Meadow Fescue
0.6 2 S59 Red Fescue
0.6 72 Alsike Clover
0.6 ; Altaswede Late flowering red
clover
Hee, S184 Wild White Clover
0.6 % $100 White Clover
40.7 35

2.2.4 The situation in 1966 on the Lancashire sites

Following reclamation, site management is of the

greatest importance. One of the sites visited in 1966, Marsh
Houses, which showed excellent sward development,
according to reports from Lancashire County

Fig 2.3 Bryn Hall in Lancashire. A reclaimed site returned to agriculture with provision for shelter belts

Council has since failed to live up to expectations because
less effective management has been carried out. Bryn Hall,
which showed less promise in sward development in

1966, has since become superior to Marsh Houses because
of more effective management. At Pennington Green,
failure to provide field drainage as part of the farm
management has meant waterlogging and invasion by
rushes; steeper gradients could possibly have overcome this
problem.

At Bickershaw, since 1964, the land has received 25
tonnes/ha (10 tons/acre) of farm-yard manure every other
year and up to 502 kg/ha (4cwt/acre) of a high phosphate
(12:18:12 units/cwt) fertiliser every year. Hay yield is
reported to be approximately 4 tonnes/ha (1.6 tons/acre)
with good aftermath grazing.

(a) Nutrient status of shale spoil. The members of the
Project who visited the Lancashire sites undertook
a sample investigation of the nutrient status of the
shale spoil and their observations were as follows
(the Project is especially indebted to the Lancashire
County Planning Department for their willingness
to allow studies to be made on the various methods
used):

(i) pH and lime requirement. The surface
materials on these sites presented a very wide range
of pH values (2.2 - 7.9) whereas most agricultural
crops can grow well only over a smaller range. For
example, at Bryn Hall there was a very small area
which had been covered with a boulder clay subsoil.
Usually this material is slightly calcareous and
therefore would not require the 10 tonnes/ha

(4 tons/acre) of limestone it received. The pH of a
sample taken from this area was 7.9. There was also
on the same site a small area where black shale was
exposed at the surface. A sample taken from this
area was found to have a pH of 2.2 and a lime
requirement of 30 tonnes/ha (12 tons/acre).
Probably this sample missed the dressing of limestone,
but even if it had been limed, the application was
only a third of what it should have received. It is
understood that a spillage of diesel oil occurred
during the contract on this area; this would interfere
with the growth of vegetation under normal soil
conditions.

(ii) Potassium. Analysis indicated that generally
potassium was available to plants in quantities such
that in future only light applications of potash
fertilisers would be required.

(iii) Phosphate. Though no analysis was successful at
that time in determining the phosphate status of

the soils, indications in the field suggested that

there was frequently a severe deficiency of this
nutrient. It was considered likely, and it has since
been confirmed, that this was caused by the soil

fixing the phosphate so that little of the applied
fertiliser was available to plant roots. More frequent
and higher applications of phosphate would therefore
have been required.

(b) Fertilisers. The fertiliser used on these sites
contained 13:13:20 units/cwt, but it did not seem
to be appropriate to shale soils. A fertiliser high in
nitrogen and phosphate and lower in potash would
have been better suited to the requirements of these
soils.

14

(c) Profile developments. Four profiles were obtained of
the Lancashire soils. Bickershaw and Whalley’s Basin
showed soils from the early reclamations and Bryn
Hall and Marsh Houses from more recent sites
(Fig. 2.4).

The profile at Bickershaw showed a deep, well
structured soil, with root penetration down to at least
200mm (8in). Organic matter was well incorporated,
the abundance of earth-worms and small animals
making a real contribution to this. The humus form
was of a mull type and the whole profile reflected

the high quality of reclamation and after-management.

The profile from Whalley’s Basin, though of similar
age, contrasted well with that of Bickershaw, the
profile showing an impoverished and wet soil. Organic
matter had accumulated on the surface, and the roots
were confined to the upper 50mm (2in) of the soil.
No sign of soil fauna activity was found in the
sample. Generally the profile showed poor
reclamation, and the vegetation a deficiency of
phosphate. Installation of an efficient drainage
system and careful management of the soil would be
required to bring this soil up to the standard of
Bickershaw.

Over part of the Bryn Hall site, the surface material
was boulder clay subsoil. The profile showed a
structureless surface horizon with sparse vegetation
and small restricted root systems. To improve this
area, attention should have been given to the
drainage of the soil and to improving plant growth.
More vigorous root systems would themselves help
to improve structure, and thus increase drainage
through the profile. High levels of nitrogen in a
balanced fertiliser programme would have helped,
but other factors such as the conditions of grazing
by farm animals would also be important. Profile
development can be a self accelerating process if
started correctly and followed with careful after-
management.

At Marsh Houses a well drained profile of a red
shale soil was exposed. Vegetation was dense and
hadroot systems which penetrated deep into the
shale. Reclamation here and surface treatment of the
soil had produced a material on which an excellent
sward had developed. This profile showed that no
additional cover of imported soil had been spread
and gave an interesting comparison with Bryn Hall.
It is also interesting to compare it with the

profile from Whalley’s Basin. Although strict
comparisons were not entirely valid, the soil from
Marsh Houses indicated that drainage was most
important and also that red shale might be a more
suitable material for plant growth than black shale.
Investigations have been continued to give more
information on this point.

2.2.5 Soil problems encountered on the Study
Tour of the Lancashire sites

It is necessary to point out that at the time the early work
was done in Lancashire, various techniques of assessment
now available had not been evolved (the techniques arising
out of our work are referred to in Chapter 8). The most
obvious conclusion to be drawn from the Lancashire sites

Whalleys Basin
1956

Bickershaw
1954

is that the material forming these sites had a high potential
for crop growth. The three difficulties most frequently
encountered were waterlogging, nutrient starvation, and
acidity and its associated toxicities.

(a)

(b)

Waterlogging. This was generally caused by
insufficient surface run off, together with low
permeability of the ‘soil’. Drastic compaction
occurred as a result of the movement of heavy
machinery over the site. This can be alleviated by
thorough subsoiling before surface cultivations start.
Slopes of between | in 20 and | in 30 seemed to be
well suited to this material for accommodating run
off without serious erosion.

Nutrient starvation. This was common on reclaimed
sites where the reclaimed shales cannot be expected
to be initially as fertile as a soil. Regular attention

needs to be paid to the fertility status of shale soils, as

they require high levels of nitrogen and phosphate,

but may need only small quantities of potash. Should

a deficiency develop in any of these, it is likely that
the sward will immediately deteriorate and severe
erosion will occur on all but the gentlest slopes.

Acidity and associated toxicities. Falling pH was also
common on these sites, and justifies a lime

Marsh Houses
1965

Bryn Hall
1965

Fig 2.4 Soil profiles from four reclaimed sites in Lancashire.

requirement test each season in the initial stages of
reclamation. Red shale, in its immediate period
after reclamation, seems frequently to be superior
to black shale in supporting plant growth.

Vigorously growing swards seemed to have the greatest
beneficial effect on the soil which, at Bickershaw, showed
rapid development when fertility was maintained. On this
site, earthworms were abundant twelve years after the
initial reclamation. It was also evident from our
investigations of the Lancashire sites that ploughing the
sward should be avoided until a stable structure has
developed in the soil. No top soil or subsoil applications
seemed to be required although large dressings of a bulky
organic material are desirable.

The seed mixture used, and its seeding rate, seemed adequate
on the Lancashire sites, though one may question the
dependence on clover for nitrogen. In the initial stages,
nitrogen supplied artificially may be better.

It should be stressed that the condition of sites transferred
to other owners following reclamation is entirely

dependent on the efficiency of the subsequent management,
and this is reflected in the condition of a site at a

particular time. Examples have been cited under Table 2.1

15

Table 2.1 Summary of Soil Findings encountered on Study Tour

Sites

Whalley’s
Basin

Bryn Hall

Marsh
Houses

Bickershaw

Pennington
Green

Water- Compac- Slope

logging tion gradient

Yes Not Shallow,

ripped associa-

tion with
playing
field use

Small Near shale

localised road

areas

None 1:20 -
1:30

None

Yes Yes Slope
shallow
at 1:50

Nutrient
starvation

N+P

N.P.K.
Localised
area on
black shale

N
Small
area of
clay
over
black

None seen

None seen

Vegetation

Root mat
being
formed.
Impoverished
soil. No
faunal
activity

Bare

Structure-
less

surface
horizon
with sparse
vegetation
and small
restricted
root system

Good
vigorous
deep rooting
sward

Excellent
vigorous
sward.
Deep well
structured
soil. Abun-
dance of
earthworms
and animals.
Mull humus
form

Invasion
by rushes

Management Acidity & Management

deficiency
toxicities

Land
drainage
not insta-
lled. Soil
fertility
not
main-
tained

pH 6.4

Lime
requirement
test. Extra
fertility
required

pH 2.2
possibly

by contr-
actor’s

refuelling

point
Lime not pH 7.9
required,
High Nin
a balanced
fertiliser
programme

Lime pH 4.8
requirement.

Quality of

initial sward

has dropped

due to less

effective

management

Nil pH 6.4

Land
drainage
not
installed.
Soil fert-
ility not
maintained.
Poaching
by cattle

associated

aggravated

Land

improvement scape

factor

Careful
grazing by
animals has
greatly
improved
the quality
of the
sward.
Balanced
fert. prog-
ramme has
also helped

High

quality of
management
has given
rise to
excellent
sward

or
land
use

Housing/
Recrea-
tional
open
space

Agricul-
ture/
Shelter
Belts

Agricul-
ture

Agricul-
ture

Agricul-

ture

16

Table 2.2 Financial implications. General breakdown of the five sites visited (Costs/unit area)

Site Area Acquisition Earthworks Cultivations Total

ha acres ha acre ha acre ha acre ha acre
Whalley’s Basin 13 32 £295 £118 £859.5 £343 £1325 £53 £1285 £514
Bryn Hall 17 180 £485 £194 £96 £38
Pennington Green 14 34.25 £372.5 £149 £92.55 £37
Bickershaw 4 10 £25 £10 £100 £40 £65 £26 £190 £96
Marsh Houses 18 45 £83.25 £33.3 £435 £174 £825 £33 £600 £2403

2.3 Afforestation in Germany

A second study tour was undertaken by members of the
research team (Doubleday and Vyle) to the Brown Coal
and Ruhr areas of Germany in 1966. The species which
have grown successfully are listed below, and the use of
soil additives to help plant growth in areas of high
pollution described.

2.3.1 Brown Coal area

K nabe (1964) described the species used in detail, and
indicated that the best soil improving pioneer plants for
afforestation were Alnus glutinosa and A. incana,
Robinia pseudoacacia and perennial lupins. Hybrid poplars
brought the highest yields on some but not all sites.
Populus X euramericana and hybrids between European
and American species e.g. P. nigra X P. angulata orX

P. deltoides, were the main species used. Interest was then
being shown in balsam poplars (P. tacamahaca) and the
different hybrids between P. alba, P. tremula, and

P. tremuloides, as well as new clones of tree willows.

2.3.2 Techniques of afforestation in the Ruhr
District

The planting of conifers has been ruled out because of
high levels of pollution. For example, the dust in the
Ruhr contains fluorine, arsenic lead, zinc, beryllium
seleniumphosphorus, ¥anadium and cadmium, and
levels of 2-3 kg/100m2 each month are obtained.
Barnard (1967) also reports that the sulphur dioxide
content of the air is between 0.2 and 0.3 mg/cbm. The
depth of dust accumulation in Essen has been measured
at 10cm. These pollution levels may be compared with
the legal limits for dust levels suggested by the Union of
German Engineers (V.D.I.) at a maximum of

+2 kg/100m2/month.

It has been found that plant growth is related to an
adequate depth of soil in areas of high pollution. 0.3m
(1ft) of soil was given as an average figure for obtaining
reasonable growth in such areas. The deciduous species
of tree used were Acer pseudoplatanus, Alnus glutinosa,
Populus spp., Quercus borealis maxima, Crataegus spp..,
Robinia pseudoacacia and Tilia spp. Twelve year old trees
were up to 7.5m (25ft) high; growth rates, however,
50-80% slower than normal, have been recorded on the
exposed slopes of heaps. A. incana and A. glutinosa 60%
with Quercus borealis maxima, Robinia spp., Tilia spp.,
Fraxinus excelsior and Betula spp. was another successful

mixture. Sorbus spp., Prunus spinosa and Rosa spp. were
amongst the species used at the edges of plantations as
part of the policy for landscape protection. Tree species
planted elsewhere in the Ruhr district were Crataegus
prunifolia, Populus tremula, PX berolinensis, Pyrus
communis, Salix alba ‘Liempde’, and shrubs included
Sarothamnus scoparius, Hippophae rhamnoides and
Lycium sp. An important matter in the success of the tree
planting was the employment of forestry officers by
some mining companies who carried out species trials.

The following conclusions were drawn from the policy and
work of planting in landscape reclamation projects
carried out under the Ruhr Regional Planning authority.

The use of top soil in areas of high pollution should
be considered.

The use of jeciduous species of trees and shrubs to
encourage the development of soil fertility should
be a prime consideration.

Berrying trees and shrubs should be used as part of
the overall policy for protecting the landscape by
helping to provide winter food for birds.

Species trials of trees and shrubs should be undertaken
to extend the range of suitable species, native species
and their improved forms, with smaller quantities of
exotics being included for investigation.

2.4 Afforestation on colliery shale in Britain

The history of planting on shale heaps goes back, at
least, to the 18th century (e.g. Seaton Delaval in
Northumberland), and a considerable body of experience
is available from the work of some Planning Departments
(e.g. Co. Durham).

2.4.1 Observations by Wood and Thirgood (1955)

The investigations carried out by Wood and Thirgood
indicated that some colliery spoils are capable of producing
quality class I growth e.g. Hawkwell Inclosure, Dean Forest,
Gloucestershire. They also made some general observations
relating to the species which could be grown on spoil and
these are given below. Reporting on the conifers, it was
noted that those preferring, or at best tolerating, near
neutral conditions seem to have been most successful,
Larix decidua andL. leptolepis, Pinus nigra vat calabrica
and Pinus nigra had all done well. Pinus sylvestris, an
adaptable species, had been widely used with some success,
but it had com pared unfavourably with P. nigra var

calabrica and P. nigra whenoccurring on the same heap.
Alnvs glutinosa, Acer pseudoplatanus, Fraxinus excelsior
and Populus spp. had all grown satisfactorily, Ulmus spp.
and Tilia spp. had also performed well. Alnus incana had
done well and it seemed likely that Alnus cordata would
do well on spoil heaps. Many other species, including
Salix spp, Robinia pseudoacacia, Sorbus aucuparia and
Crataegus spp., had been recorded.

Recommendations included the use of a high proportion
of Alnus spp. on heaps weathering to clayey material, and
on lighter bummed materials a higher proportion of Betula.
Alnus and Betula were regarded as the safest pioneers, and
with them Acer pseudoplatanus might be used on all sites.
Populus spp. could be planted where there was adequate
moisture; they should not be carried high on the slopes,
and might best be confined to screens round the base. Care
should be taken to choose canker resistant varieties;
reliable clones of Populus x serotina, gelrica, robusta and
eugenii were available.

2.4.2 Planting in Lancashire - early conclusions
by Casson and King

Lancashire was among the pioneers of tree planting of
colliery spoil, and an extensive investigation was
commissioned by the Planning Department and carried

out by Rees and Warwick of Birmingham University. This
enabled some of the practical conclusions to be rationalised,
and Casson and King (1960) reported on these
investigations:

(a) Colliery spoil heaps appear to be sufficiently fertile to

maintain tree growth.

(b) Sufficient moisture is usually available after establish-
ment, although losses can be high in prolonged dry
summers in the early stages. The choice of species
must be governed by site factors, but atmospheric
pollution does not rule out certain conifers.

(c) Where pollution and exposure is severe, it is essential
that a nurse species be extensively used, and where the
site is bare, the main function of the nurse is to
improve site conditions (i.e. shelter, stabilisation of
the surface, shade and surface moisture, build-up of
humus). Alder has been found to be the first choice

in Lancashire.

(d) Plants used should have a well developed fibrous

root system and should be fairly small and sturdy.

(e) Species.

Alder is the first choice as it is the most successful,
even where pollution and exposure are most

severe or soil conditions detrimental. Common alder
(Alnus glutinosa) is most satisfactory as a nurse
because it develops a bushy habit which soon affords
shelter and shade, although the height development
is somewhat limited. Where alder is planted in
mixture, grey alder (Alnus incana) should be utilised
or used for beating up, because its foliage is not so
heavy and it will continue to afford shade and
shelter to a greater height.

Birch (Betula) is difficult to establish on unburnt
shale, but is more readily established and thrives well
on burnt shale.

18

2.4.3

White poplar (Populus alba) has been successful and
thrives best when planted in loose material and is
excellent for checking erosion.

Qorsican pine (Pinus nigra var calabrica) has given
excellent results where there has been sufficient
shelter, although it has also done well in more
exposed situations, especially where planted in
mixture with a vigorous nurse. Recent work carried
out by the Nature Conservancy at Merlewood shows
that Corsican pine has exceptional qualities in
building up soil nitrogen.

Lodgepole Pine(Pinus contorta) has been used more
recently than Corsican pine, and the indications are
that it may be as good.

Sycamore (Acer pseudoplatanus) suffers considerably
from dieback. Only after there is considerable shelter
from the nurse species does it throw up a leading
shoot, and it appears that it should not be used in the
early stages of establishment.

Beech (Fagus sylvatica), when planted at the same
time as the nurse species, stands still for years,
although odd trees have thrived on unexpected sites
when there is some shelter. It may be that beech and
sycamore, being rather demanding, suffer not only
from exposure, but from soil comitions which are in
the course of modification by the nurse.

Japanese Larch (Larix leptolepis) has shown vigorous
growth when planted in sheltered positions, but has
shown a fairly high rate of failure during severe drought.

Ash (Fraxinus excelsior) has failed on all sites and
positions. Sitka spruce (Picea sitchensis) had only been
planted on two sites, but results are encouraging.

Common Osier (Salix viminalis) is the most useful

species of willow, showing vigorous growth. Grey

willow (Salix cinerea) on the other hand, has shown

only slow growth. |

Certain species, notably Spanish Chestnut (Castanea sativa) |
as well as the ash, beech and sycamore, appeared to be
establishing themselves satisfactorily in the first year, but
showed severe die-back each year subsequently. From
evidence obtained on some grass seeding experiments on
shale elsewhere, it may be that shale breakdown has

caused acidity and other chemical changes, creating soil
conditions which may hold these species in check.

Later conclusions on tree planting in
Lancashire by Casson and King

The following conclusions are based on the findings of
Casson and King (1967), expanding upon and supplementing
their findings of 1960.

(a)

(b)

Size of plants. Plants must be selected. Small sturdy

trees 0.3 - 0.45m (12in - 18in) high should be used
to minimize the effect of wind damage.

Planting method. The technique adopted in the early

stages was to blanket the area under normal forestry
practice using a nurse species of Alnus incana or /

A. glutinosa, Betula and Salix caprea.

(c)

Application of fertiliser. Although composts and

artificial manures to encourage growth had been

experimented with at various times, no concrete

(d)

(e)

(f)

cacelusions had been reached. However, if fertiliser
was used, it was recommended it should be mixed
with a little soil and put in the planting hole, rather
than spread on the heap with subsequent loss by
wind and rain. The use of smaller quantities would
save expense.

Range of species planted. Many species had been
planted, these included Alnus glutinosa and A. incana,
Acer pseudoplatanus, Betula spp., Fagus sylvatica,
Populus alba, Castanea sativa, Pinus mugo, Larix
decidua and L. leptolepis, Fraxinus excelsior, Acer
platanoides, Picea sitchensis, Ulmus spp., Quercus
cerris, Pinus nigra vat. calabrica and P. contorta var.
latifolia.

Observations on blanket planting. It was noted that on
some sites the growth of the nurse species had been
insufficient to offer protection to the chosen final
crop species, and this had resulted in the dying back
of leading shoots and the death of many of the plants.
On one particular spoil heap, the nurse species
chosen had reached a stage after five growing seasons
where it was offering a definite protection to the
Pinus nigra var. calabrica, and if this protection had
been there when the pine was planted, it is quite
certain a lot of beating up could have been avoided.
To overcome this on more difficult sites where it
was known that protection would be a definite
benefit, A/nus spp., Betula and Salix caprea were
planted in groups or narrow belts. As and when
these species became established and offered
protection (which could be from 3-5 years), the
remainder of the area was then planted up with the
final crop species. The advantage of this is that a
large area can be planted each year, and the cost of
beating up and weeding is reduced considerably.

Notes on the performance of individual species.
Alnus glutinosa was most satisfactory as it develops
a bushy habit which soon affords shelter and shade.
It was observed that after the first few years of
rapid growth a considerable amount of die back
occurred and many shoots then sprang from the base.
On investigation, holes were dug to ascertain what
was actually happening to the root growth, and it
was apparent that whilethe roots had gone down to
a depth of 1.5 - 1.8m (Sft - 6ft) they were very few
in number with very little fibrous roots and most

of the root system was now dead or dying. However,
while this was occurring a mat of fibrous roots was
developing from the base of the tree to about 0.3m
(ift) in depth and vigorous new shoots were now
showing and forming a very effective windbreak.
Within ten years Alder had reached a height of

4.5 - 6m (15ft - 20ft).

Betula species can be seen growing from natural
regeneration on many spoil heaps. It is found to be

a most difficult species to establish from transplants.
It no doubt requires more careful siting and should
only be used on shales that retain the moisture much
longer and where, if possible, other vegetation has
become established.

Populus alba is a good species particularly where the
site is dry and subject to erosion. It promotes root
suckers which run many feet and form a retentive
root mat.

Acer pseudoplatanus, when planted at the same time
as the Alnus glutinosa had shown only small growth
each year. However, as soon as the Alnus provided
some shelter, the Acer began to thrive, as did Fagus
sylvatica. Pinus nigra var. calabrica and P. contorta
had been most successful on all sites, even in areas
of atmospheric pollution. Of the two, P. nigra var.
calabrica showed the better growth, reaching a
height of 3.6 - 4.5m (12ft - 15ft) within 10 years
and again this species benefited from the shelter
provided by the Alnus. At this stage the Alnus
needed cutting back to relieve the Pinus.

Larix leptolepis, while showing considerable growth
in the first three to four years, did show a tendency
to fail during severe drought and many also seemed
to check and grow only 50 - 75mm (2in - 3in) for

a couple of years. Once out of check, growth became
normal again showing some 0.3 - 0.45mm (1 2in -

1 8in) growth annually.

It is interesting to note that Casson and King’s investigation
of planted and naturally regenerated sites in the West
Riding confirms the importance of considering rainfall and
soil toxicity in the initial phases of planting and mainten-
ence. However, while establishment may be more difficult
there are indications that the prospects of producing
effective timber crops may be better east of the Pennines.

In 1966 the planting at Bryn Hall contained no coniferous
species, the main species being Acer pseudoplatanus (36%),
Alnus glutinosa (25%), and hybrid balsam poplars

P. tacamahaca X trichocarpa, 32 hybrid poplars P X Serotina,
and P X Robusta, Salix Caprea, the remainder being made
up of Salix alba vitellina, S. purpurea, Quercus borealis
maxima, and Acer platanoides. An example of a simpler
planting plan is shown in Fig. 2.5.

LANCASHIRE COUNTY COUNCIL g

TREE PLANTING 1965/6 =

SECTION 89 NATIONAL PARKS & ACCESS TO oy
¥

rs

THE COUNTRYSIDE ACT 1949

BOARDMANS HEIGHTS
WITHNELL U.D

=
z
%
A
%

CAider

¢}| 600
Sycame is

scale 11250
plan redrawn from
no. DEV. 706

Fig 2.5 An example of a simple planting plan for a spoil
heap in Lancashire, using only deciduous species (Courtesy
of the Lancashire County Planning Department).

2.4.4 Planting in Durham

Richardson et al describe the early success of planting in
Durham. The post war planting has also been examined by
them and is reported in Chapter 9.

Up to 1954 a number of pit heaps and other waste heaps
were acquired and afforested by various authorities and
associations in the northern Region. It is thought that
between 40 - 8F ha (100 - 200 acres) were dealt with,
mainly in County Durham. From 1954 - 1960 Durham
County Council itself undertook such planting and some
43 ha (108 acres) of trees were planted on twenty four
sites. Of these, four sites have since been graded out. Of
the remainder which may be considered to be establishing
successfully, there are 21 ha (53 acres) mainly on seven
sites. Since 1960, with improved grants, the tendency

has been to undertake grading and grassing, and of 6.8 ha
(17 acres) planted only 1.6 ha (4 acres) remain. However,
because trees are capable of making a valuable contri-
bution to the landscape, the Botany Department undertook
a survey as described in Chapter 9. The grading out of
slopes to 1:8 allows for agricultural management and may
allow for the incorporation of tree planting for shelter
purposes. Where slopes must be steeper, afforestation
techniques may be used but suitable access should be
provided for possible liming and fertiliser maintenance.

2.4.5 Financial implications

Each site must be treated on its own merits, and costs may
vary considerably, taking into consideration the cost of
forest transplants as against larger stock. However, larger
stock may soon over-top weeds and, provided competition
is not too severe from the weeds, the cost of weeding may
be much less than with forest transplants. It may be
necessary to look after forest transplants for up to twenty
years. Larger plant stock used in Lancashire such as

Betula spp. and Salix caprea at 0.3m (10in) and Alnus spp.
at 1.4m (4ft 6in) can thus make a contribution in
reducing weeding and establishment costs.

Neustein (1970) reports on small scale trials using the
relatively simple method of pot planting, and concludes
that satisfactory survival and early growth (and fair
prospects of continuing health, assuming further fertil-
isation) can be obtained on some types of parts of
colliery spoil heaps. The main diagnostic factor appears to
be the presence of natural vegetation - even in quite sparse
amounts. It is presumed that natural vegetation reflects
the age (degree of leaching), stability, and exposure of the
site. Hence, as far as possible colonised spoil heaps should
be planted undisturbed. Although the small scale of the
trials precluded realistic costing, a reasonable estimate
could be made in costs/unit area, based upon the 1970
figures.

acre ha
Cost of transplants 1500 at £10 per 1000 = £15 £37.5
Cost of pots £9 per 1000= £14 £35.0
Cost of potting £12 per 1000 = £20 £50.0

Cost of planting £20-£40 per 1000 = £30-£60 £75-£150

Fertiliser-
material and application

£10 peracre = £10 £25

£90-£120 £225-£375

Fencing, supervisory overheads and transport are additional
charges, but are not included because they vary in accord-

20

ance with the particular layout, shape of planted areas etc.
Figures given by Lancashire indicate planting costs to be of
a similar order, with the observation that fencing may be
up to half the cost of the scheme.

2.5 Allied research projects

Early work has been undertaken by a number of Govern-
ment Bodies such as the Commonwealth Agricultural
Bureau, the Forestry Commission and the N.A.A.S.
Individuals associated for many years with derelict land
have made notable contributions, Stamp, Beaver, James and
Oxenham to name but a few. The County Planning Depart-
ments of Durham, Lancashire, and West Riding of Yorkshire
have laid down trials and have also been responsible for the
physical action needed to remove derelict land in their
areas. Different Departments in a number of Universities
have been co-operating with County Councils, County
Borough Councils and other authorities to investigate
certain problems.

2.5.1 Past and present research projects

Bibliographies have been prepared by Whyte and Sisam
(1949), the Ministry of Town and Country Planning
(1949) and Knabe (1957-8); other contributions to the
bibliography on reclamation are set down at the end of
this chapter. The Forestry Commission in their Research
Branch Paper No. 17 (1955) described the character-
istics of colliery spoil heaps, and make recommendations
on the type of plant material, and method of planting.
The N.A.A.S. have co-operated in the Swansea Valley
Project. Regional-Offices of the N.A.A.S. in the West
Riding and the Midlands have made valuable contribu-
tions with regard to grassing recommendations and shrub
collections. More details of these will be given in
Chapter 10.

Botanical studies have been undertaken by Birmingham
University, particularly in relation to Pulverised Fuel

Ash. Ph.D theses relating to this topic were by Sidrak
(1955), Jones (1958) and Lewis (1961). Reed directed

the project which was done at the instigation of the
C.E.G.B. The University of Leeds, Department of
Agriculture, has also conducted experiments on P.F.A.
(1964). At Newcastle, work has been undertaken in the
Botany Department over a number of years by Richardson,
Greenwood, Shenton and Dicker, to mention a few, on
various aspects of the problems of growing vegetation on
colliery shale. Warwick (1958) of Birmingham University
undertook a study of ‘Plant nutrition on Colliery Waste’
for a Ph.D thesis. The Lower Swansea Valley Project has
been in the forefront of interdepartmental research
projects with a wide range of discipline participating and
co-operating with the Swansea C.B.C. The Report was

first published in 1967, based on information available

in the Autumn of 1966. The Department of Biology of the .
University of York is co-operating with the West Riding
County Council and advising on particularly different
vegetational problems. Studies are also being undertaken
on the chemical nature of the colliery shales and nutrient
cycling.

The Department of Civil Engineering at the University of
Leeds is also collaborating with the West Riding County
Planning Authority as previously indicated.

———

2.6 Setting the guide lines for the project

The Landscape Reclamation Research Project at the
University of Newcastle started in 1964 with preliminary
site selection, two sites each being selected from C. Durham,
Newcastle upon Tyne, and Northumberland. The Landscape
Design Section in the Department of Town and Country
Planning drew up plans for six sites from 1965-1968, but
because of difficulties two sites were withdrawn and have
since been replaced with three further sites. Site descriptions
are given in Chapter 3, and were based on engineering and
soils assessments and upon landscape survey techniques
described in Chapter 5. The plans, along with approximate
estimates of costs prepared by a firm of chartered Quantity
Surveyors, Douglas Macara/Groves/ Associates, were sub-
mitted to the Ministry of Housing and Local Government.
Following final approval, the Drawings were sent out to
tender along with a Bill of Quantities and Specification.
Tenders having been accepted by the respective Councils,
work started on the sites and was supervised by the Land-
scape Design Staff of the University. Physical and other
problems encountered on the sites are described in Chapter
6. Grass establishment on sites is an important aspect of

visual improvement and for after-use of the sites, and to
this end the Departments of Soil Science and Botany have
co-operated actively and have been intimately involved
over the period; their contributions are described in
Chapters 8 and 9 respectively. The situation on the sites as
at 30th April, 1970 is shown in Table 2.3.

Grass mixtures, seeding rates and seeding techniques for
agriculture, public open space, erosion protection and prior
to forestry planting are described in Chapters 9 and 10.
Species, size of planting stock, methods of planting and
fertiliser treatments are also included in Chapters 9 and 10.
Financial and contractural aspects are given in Chapters 11
and 12.

2.7 Conclusions
(a) Good management after the initial contract work is
essential, and studies of previous reclamation projects
revealed examples where good grass coverage

initially had failed to maintain quality because of poor
management.

Table 2.3 Landscape reclamation research project. The situation as proposed at 14th October 1966 and the real situation

as at Ist March 1971

Site Revised Sketch. Ministry Working Final Final L.A. Outto Contract Contract Defects
brief Approximate provisional dwgs, Ministry approval tender start complete liability
estimate. approval bill of approval period
Approval by Qtys. 12
L.A. months
from
issue of
substan-
tial com-
pletion
cert.
Egerton Gardens Feb ‘66 Mar ‘66 July ‘66 21.11.66 Dec ‘66 Jan ‘67 Feb ‘67 Dec’67 Jan‘70
July ‘66 Dec ‘66 Mar ‘67 Dec ‘68
Roddymoor 31.10.66 30.11.66 26.2.67 Mar ‘67 April ‘67. May ‘67 June ‘67 = April/May 30.4.70
Sept ‘67 1.1.68 ‘68
30.4.69
Haswell Nov ‘65 30.11.66 31.12.662 6.2.67 Mar ‘67 April ‘67. May ‘67 June ‘67 ~— April/May
Colliery 8.12.66 Decision deferred Public inquiry into extractidn of Red Shale ‘68
Site withdrawn Mar. ‘68
Northbourne 28.2.67 31.3.67 April ‘67 May ‘67 June ‘67July ‘67 May ‘68 Jan ‘70
Park 21.10.66 31.12 66 10.10.66 Mar ‘67 Not necessary April ‘67Mar ‘68 Jan ‘69
Percy Pit 1.11.66 31.1.67 28.2.67 30.4.67 May ‘67. June ’67 = July ‘67 Aug ‘67 June ‘68
April ‘66 From June ‘66 Private firm investigation into extraction of coal site
Site withdrawn July ‘69
Big Waters 31.1.67 28.2.67 May ‘67 June‘67 July ‘67 Aug ‘67 Sept’67 Aug ‘68
Mar ‘69 May ‘69 May‘70 May ‘71
Replacement
Sites
Felling May ‘70 Oct ‘70 June ‘70 Nov ‘70 1.2.71 31.3.72 31.3.73
Nov ‘70
Maria Colliery Oct ‘68 Dec ‘68 Dec ‘68 Dec ‘68 Jan ‘69 Sept ‘69 ? ?

Jan ‘69

$$$ — LL L_L_—
2

1

(b) Land drainage problems are likely to arise from the
compaction by heavy machines. Slopes of | in 20 to
30 often accommodated run-off of surface water
without causing erosion, and are an insurance against
subsequent failure to install land drainage systems
and against subsequent failure of such systems due to
the ‘settling down’ of regraded land.

(c) The new developing ‘soils’ of reclaimed sites should
be analysed at frequent intervals to identify fertiliser
ingredient deficiencies.

(d) Coniferous planting should be avoided in heavily
polluted areas. Above normal topsoil depths encourage
growth in polluted areas.

(e) The experience gathered from the study of sites else-
where constitutes an important aid in clutivation,

fertilising, seeding and planting decisions. For example,

the alders stand out as trees with a high degree of
success in growing in the particular conditions of
reclaimed sites.

References

Barnard, E. (1967) ‘The contribution of the landscape
planner to urban industrial and road development
and outdoor recreation’. IUCN Tenth Technical
Meeting Landscape Planning Committee, IUCN
Publications, Morges.

Blakely, R.D. (1964) Reference List for Reclamation of
Strip Mine Areas. U.S. Dept. Agr.

Bowden, K.L. (1961) A Bibliography of Strip Mine
Reclamation 1953-1960. Univ. Mich. Dep. of
Conservation, Ann Arbor.

Briggs, R.A. (1966) Landscape Reclamation.
Implementation. Inst. of Adv. Arch. Studies. York.

Casson, J. and King, L.A. (1960) Afforestation of derelict
land in Lancashire. Surveyor. London. 119. pp. 1080-
1083.

Casson, J. and King, L.A. (1967) Forestry in the Industrial
West Riding. Brit. Ass. Adv. Sci., pp. 9-15.

Coates, U.A. (1960) Experiments in grassland establish-
ment on colliery shale, Bickershaw Reservoir Site.
Lancs. C.C. County Planning Dept.

Commonwealth Bureau of Soils (1965) Bibliography on
spoil bank soils and their reclamation. (1965-1956).
No. 1027CBS, 20.

Downing, M.F. (Ed) (1966) Study tour of Landscape
Reclamation sites in the Lancashire coalfield.
Interim Report No. 2. Landscape Reclamation
Research Project, University of Newcastle upon
Tyne.

Forestry Commission (1963) /ndustrial Waste Land and

its Afforestation and Reclamation. A bibliography of
British references.

Funk, D.T. (1962) A Revised Bibliography of Strip Mine
Reclamation. U.S. Dep. Agric. For. Service, Central

States Forest, Experimental Station, Columbus,
Ohio.

22

Goodman, G.T., Edwards, R. and Lambert, J.M. (1965) )
Ecology and the Industrial Society. Blackwell
Scientific Publications, Oxford.

Johnson, C. (1966) Practical operating procedures for
progressive rehabilitation of sand and gravel sites.
Project No. 2 1964-5. University of Illinois/National
Sand & Gravel Association of America.

Knabe, W. (1957-1958) Contributions to bibliography on
reclaiming mined areas (in German, English
Summary ). Wiss. Z. der Humboldt-Univ. Berlin,
Math. Nat Reihe. VII. 291-304.

Knabe, W. (1964) Methods and results of strip mine
reclamation in Germany. The Ohio Journal of
Science.

Lancashire County Council (1962) Derelict Land problems.
Lancs. C.C.

Lancashire County Council (1965) Dereliction, Land
Reclamation and Tree Planting in the Administrative
County of Lancashire. Progress Report.

Lancashire County Council Cultivation, liming, manuring
and seeding of land at Bryn Hall and Bam furlong.
Bill of Quantities.

Ministry of Housing and Local Government (1957)
Bibliography No. 107: Derelict Land: a select list
of references.

Ministry of Housing and Local Government (1963)
Bibliography No. 107: a select list of references.

Ministry of Housing and Local Government (1965)
Bibliography No. 107. Addendum, London.

Ministry of Town and Country Planning (1949) Country
planning , reclamation of mined land.
Bibliography No. 84.

Neustein, F.A. (1970) Report on Forestry Commission
trial plantings on Pumpherston shale bings.

Oxenham, J.R. (1966) Reclaiming Derelict Land. Faber,
London.

Stamp, L. (1951) The reclamation of land disfigured by
industrial uses .J. Roy. Soc. Arts. Vol. C. pp. 97- 122.

Vyle, C.J. (1964) Industrial waste land - its afforestation
and reclamation. A list of references. Landscape
Reclamation Research Project. University of
Newcastle upon Tyne. (Duplicated Typescript).

Vyle, C.J. (1966) A collection of references on landscape
reclamation. University of Newcastle upon Tyne,
Landscape Rec. Res. Project. Duplicated Typescript.

Vyle, C.J. (1967) Addendum to above.

Whyte, R.O. and Sisam, J.W.B. (1949) The Establishment
of Vegetation on Industrial Wasteland. Common W.
Agr. Bur. Jt. Publ. No. 14 Aberystwyth.

Wood, R.F. and Thirgood, J.V. (1955) Tree planting on
colliery spoil heaps. For. Comm. Res. Br. Paper No.
LZ

Chapter 3 Research sites

by M.F. Downing

3.1 Historical background

The history of coalmining in the north east of England
dates back to the Romans and even during the middle

ages coal was shipped to London and other places. By
Tudor times shortages of timber had resulted in renewed
efforts at exploitation of the mineral. As early as the
seventeenth century mining at a depth of 400 ft was not
uncommon, and by the nineteenth century depths of
several thousands of feet were commonplace. The history
of mining was one of hardship and degradation, punctuated
by unspeakable disasters. The sites on which the project
has operated are no exception and it is salutary to rememb-
er that the legacy of dereliction represents an age and an
industry careless not only of land and aesthetics, but also
of human life and dignity. It would be fitting if some

way of commemorating those who in past years have
suffered and died so ignominiously in the cause of human
progress could be incorporated in the new reclaimed land-
scapes.

Not all of the research project sites have been associated
with coal mining, but six of the nine were the sites of
working deep mine pits. The earliest of these is Heworth
Colliery where boring to the high main seam commenced
in 1763. This mine ceased operations so recently that the
pit head winding gear was still standing in 1970. At Percy
Pit, Newbu rn (Fig.3.1), the site was an operative coal

mine but also served as a centre for the operations of the
Walbottle Colliery Company which worked a number of
other pits, inter-connected wagon ways, and pit railways.
The nearby Duke Pit was sunk to the Brockwell seam in
the late 18th Century and it is recorded that coal was
being worked from the Beaumont seam in 1787. The
Coronation, Wellington, Blucher and King Pits followed
the Duke Pit, the Blucher Pit being opened in 1815. The
lease on the Royalty was held until 1867 by Messrs. Lamb
but in that year the colliery closed down. Stevenson & Co.
who opened the nearby Isobella Pit in 1869 leased the
Royalty in 1877 having sunk the Derwentwater shaft in
1876. The Blucher Pit was re-opened in 1901 and operated
by the Throckley Coal Company. The Percy Pit site was the
centre of a web of wagon ways, tramways and mineral rail-
ways linking the outlying pits to the public railway. Wagon-
ways extended to Maria Colliery, apparently opened in the
last quarter of the nineteenth century, North Walbottle
Colliery and Throckley Colliery . The North Walbottle
Wagonway was laid with iron rail to the Coronation Pit in
1794.

Haswell Colliery also has considerable historic interest,
being the site of one of the many great tragedies of north-
east mining. It is recorded as one of the first sites where
sinkings were undertaken to prove coal below the magnes-
ian limestone. This was undertaken in 1811 by Dr. William
Smith. Twenty years later on 28th February 1931, the
Engine Pit commenced. After excavating 54ft, this was
abandoned because of running sand and the New Engine
Pit was begun in the same year. This shaft was sunk first to
the Hutton Seam, and on to the Beaumont seam by 1840.
The first recorded shipment of coal was on 2nd July 1936.

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River Wear

10 km (16miles)

Location of possible and actual research sites
(a) in the area of Newcastle upon Tyne
(b) in the area of Durham

In 1844 on 28th September at 3 p.m. there occurred what
was described in Fordyce’s History of Durham as “one of
the most fatal cases of explosion on record”. This was
described as taking place in the Little Pit at a point called
Meadows Flat 1400 yd from the shaft. This tragic
explosion resulted in the loss of 95 lives and this was attri-
buted by Professor Faraday, who carried out an enquiry
after the event, to suffocation by chokedamp. The winding
engine house which still stands at the southern end of the
site is regarded as a very fine early example of its kind. The
walls are 8ft thick at the base and this has led to the
suggestion that it dates from the very early years of the
nineteenth century. If this is accepted it must be assumed
that it was built in connection with Dr. Smith’s original
borings.

The pit was evidently worked for some years after the
tragedy, as a reference to the pit with ventilation maps of
the upcast and downcast pits occurs in the Proceedings of
the North of England Institute of Mining Engineers for
1859. The same Proceedings include a paper given on 8th
December 1883 on “The Haswell mechanical coal getter, an
invention for working coal without the need for gunpowder
or explosive” by W.F. Hall. It is believed that the pit ceased
operations around the turn of the century.

23

Roddym also has some claims to historic interest, notably
nt which used to stand on part of the
The Victoria County History of Durham records that
Roddy
Roddymoor in 1836 and that in 1844 a sinking was put
wn by Mr. R.A. Heslop to work the Brockwell or Main

\ et what

moor Royalty were in progress at Old

was known as the New Colliery The
ke ovens w removed, bore a plaque with the following

yvens are part of the first by-product coke

ven plant erected in Great Britain. The original battery
25 ovens was built for Pease and Partners Ltd. by
Henry Simpson founder of Simon Garves Ltd., in 1882

$
7

1uously for more than seventy years’.

It is hoped that the orginal battery may be re-erected at the
Industrial Museum at Beamish Hall

At Big Waters, the influence of the Pits surrounding and
ndercutting the whole of this part of Northumberland has
esulted in the subsidence of a large area creating a ‘mining
flash’, a lake on the deadwaters of the Ouseburn.

St Anthony’s Point at Walker has been renamed
Northbourne Park after the Northbourne family which
had estates in this neighbourhood for many years. It was
the site of ballast dumping from ships coming up the

ne, probably for many hundreds of years. St Anthony’s
Point was at one time the site of a mansion and garden
belonging to one Henry Ibbetson Esq. The house which
had a farmhouse, cottage and outbuildings was probably

built in the early eighteenth century and the walls of the
original garden still remain on site, having been incorporated
into the walls of a car park. From contemporary sources it
appears that the mansion was a handsome and elaborate
structure. Another house standing on the south east

corner of the site was reputed to date from the fifteenth
century. This was standing when reclamation began, but
being in a Very poor state of repair was subsequently
demolished. A large area was occupied in the nineteenth
century by a lead works. At the western end of the site

can be seen the remains of a slipway at which small trading
ships used to transport millstone grit for milling. The river
walls were constructed in 1842.

Egerton Gardens is located in a part of South Benwell
known as Paradise; part of the site was occupied by steep
rows of terrace housing dating from the early nineteenth
century. There is evidence also of industrial operations
contemporary with the housing including a waste heap from
a foundry.

3.2 Site descriptions

The tables included with this chapter give brief notes on
the location, size, and climatic and pedological conditions
of each site. The visual description and end use are also
presented in these tables. This information is included to
serve only as a broad introduction to the site. Detailed
information on specific aspects of the individual sites is
found in the appropriate succeeding Chapter.

g. 3.1 Percy Pit: Newburn conical heap dominating miners’ terraced housing, now demolished.

3.3 Selection of sites

3.3.1 Original basis of project

As indicated in Chapter 2, initial discussions on the setting
up of a project began in 1963. The financial arrangements
at that time proposed and those subsequently adopted, are
also discussed in that chapter. From the outset the local
authorities co-operated very fully and enabled the
University to select six sites from a number offered, to give
a useful range of research activities.

The passing of time during negotiations and the changing

nature of the project resulted in changes of the sites selected,

as well as the University personnel involved. Originally the
Departments of Botany, Civil Engineering, Soil Science,
Surveying, and Town and Country Planning were to have
been fully participating members of the project. Circum-
stances forced Civil Engineering to withdraw, and Survey-
ing was unable to participate as fully as at first envisaged
although the continued and valuable support this Depart-
ment has given should be recorded.

3.3.2 Original sites and research interest

It is interesting to record the six sites originally selected and
the research interests on which the selection was based. They
were as follows:

(a) Trimdon Grange, Trimdon, Co. Durham.This was
described as a ridge shaped pit heap with mostly
recently tipped black shale.

Problems and lines of research listed were:

(i) Reshaping with consequent erosion slip and
vegetation establishment problems.

(ii) Investigation of possible coppicing, stool
shooting, and other “unconventional” economic
forestry practices.

(iii) Concentrated examination of various approaches
to limited areas for first phase treatment. (sic)

(iv) Comparison of costs of reshaping and spreading
approaches.

(v) Drainage problems in relation to slip and
vegetation establishment.

(vi) Soil building processes.

(b) Chester Moor, Co. Durham described as derelict areas

in a village.
(i) Study of immediate problem of improving
appearance.

(ii) Study of costs of alternative solutions e.g.
removing remains of demolition, creating
contoured surface using different materials.

(iii) Soil development from different materials.

(iv) Natural succession of plants and processes to
speed this process on areas of demolished
housing.

(v) Future use of land.

(vi) Comparison of costs for terracing and contour-
ing.

(vii) Surface drainage.

(viii) Vegetation, the contribution of different
species to the development of soil fertility.

(ix) Establishment of grass sites after demolition of
buildings.

(c) Montague Colliery, West Denton, Newcastle upon
Tyne. A medium sized pit heap in a restricted area

amidst extensive urban housing development. This
site offered the opportunity to investigate:

(i) Operating plant on a restricted site, with the
problems and potential nuisances to neighbour-
ing properties which these would represent.

(ii) Drainage of compacted hard surfaces which
could not economically be removed.

(iii) Selection of species and techniques to establish
vegetation which will not be subject to severe
damage particularly by children.

(d) Egerton Gardens. Derelict land south of Egerton
Street, Scotswood, Newcastle. This site was thought
to offer the possibility of:

(i) Investigation of the minimum level of inform-
ation (drawings and specifications) to enable
competitive tenders to be obtained and submit-
ted for grant.

(ii) Studies of the establishment of vegetation on
derelict sites in active industrial areas.

(iii) Species and techniques of planting for urban
open spaces in the conditions of (b) above.

(iv) Use of derelict material to form play and other
surfaces.

(v) Maintenance of soil fertility in active industrial
areas.

(e) Big Waters, Seaton Burn, Northumberland. The site
as originally defined included 78 acres, and research
problems were listed as:

(i) Planting of reclaimed land to create wildlife
habitat.

(ii) Stabilization of flood waters to control lake
level.

(iii) Development of soil in areas of high watertable.

(iv) Planning problems of providing active recreation
facilities within a wildlife habitat.

(f) Spoil Heap, Walbottle, Newburn, Percy Pit.
This site was said to give the opportunity for
investigations as follows:

(i) Reshaping a heap that was a prominent shape
in the wide landscape and which could not be
totally removed.

(ii) The establishment of vegetation on steep shale
slopes where some pollution occurs.

(iii) The development of soil in the same conditions.

3.3.3 Final selection of sites and works

Three of these sites (d,e and f) still form part of the project.
However, by the time the financial basis of the research had
been decided, nearly two years had elapsed and the first
three sites selected were, for one reason or another, no
longer available. These were replaced by Roddymoor at
Crook, Haswell Colliery, and St Anthony’s Point. After the
preparation of sketch plans, problems of acquisition resulted
in Percy Pit and Haswell Colliery being replaced by the sites
at Maria Colliery, Copperas Lane and Felling. These
omissions and introductions resulted in some changes in the
direction of enquiries, notably by the omission of the
village improvement scheme at Chester Moor. This, with
hindsight, is seen to be an advantage since, had this topic
remained, it would have resulted in an undesirable broaden-
ing of the basis of research. The final selection has channell-
ed the development of research into a number of clearly

25

defined topics, with each site providing a different insight
into a topic and its problems, rather than introducing new
topics. Some sites have special features of interest and thus
may be thought to give the lie to this generalisation. It is,
in the main however, correct, and as the layout of chapters
of this book indicates, the organisation of research into the
general topics which are most significant represents a more
coherent approach than the first tentative proposals.

3.4 General research interests

The subjects covered by the succeeding chapter titles and
subheadings, for example, landform design, methodology
of landform design, land drainage, soil-forming materials
and botanical studies of natural and planted vegetation on
colliery shale, can be studied on all the sites and the varia-
tions in site conditions make it possible to see each problem
more fully. Special problems which require particular treat-
ment can also be seen in the context of the total pattern

of reclamation procedures.

3.5 Research interests associated with individual
sites

It is nevertheless possible to pick out subjects and aspects
of the major research topics which are particularly associa-
ted with, or specially suitable for study on individual sites
because of situation, topography or land use requirements.
These special lines of study and any specific trials related
to them are listed site by site below.

3.5.1 Northbourne Park, St Anthony’s, Newcastle
upon Tyne

This site (Fig.3.2) has provided the opportunity to investi-
gate the development of soils on areas affected by industry
and development other than coal mining. The aim of this
work has been to raise sub-optimum soil conditions by
contrasting methods, including the application of sewage
sludge (3 in cover) to allow adequate plant growth and to
compare the methods used. Field trials to test a range of
plants and soil treatments in site conditions have been
included on this site. The investigation of steep slope
stabilization was originally envisaged as a major feature of
this site but the establishment of the separate, but closely
linked steep slopes research project, resulted in this aspect
being omitted. An evaluation has yet to be made of the appli-
cation of agricultural grass seeding rates to recreation uses
as attempted on this site.

3.5.2 Egerton Gardens

The problems of extreme hard wear and vandalism as an
influence on the design approach have been well illustrated
on this site (Fig.3.3) and to a less marked extent at
Northbourne Park. An experiment involving stooled plants
to provide dense growth on embankments is in the course of
assessment, though the com parative trials of three methods
of grass stabilization by mechanical means were invalidated
by a contractors error. Four methods of seeding were adopt-
ed.

(a) Hydromulching

(b) Seeding bitumen spray
(c) Seeding and P.V.A.
(d) Seeding alone (control)

Unfortunately the hydromulching sub-contractor sprayed
the entire embankment, including an area which had been

26

Ca

KEY
2A FINISHED CONTOURS

STANDARD TREES

SHRUBS

U/L DINGS

25 50 m (160 ft)

°

“a

1

TAN
PAS
a
Ss

“9

\

EY
BF Z)

WELL ROAD

souTH BEN

RAILWAY

ED ABT ey

Fig 3.2 Northbourne Park: plan of reclamation proposals

EGERTON STREET

KEY

0 FINISHED ConTOuRS

~~ SMALL Sémi MaruaRe Teees

>

. SS STANDARD rRers
STORMED TeeESs

CZ seuss
E53 FORESTRY PLANTING

—_—— www
° 10 20 30m( 100)

Fig 3.3 Egerton Gardens: plan of reclamation involving a series of terraces

27

acted, or indeed paid to do. The experi-
red. Some parts of the site have been

sown with experimental mixtures of grass and herbs to see
as of interest requiring little maintenance could be

eated. The assessment of these mixtures is as yet incom-

3.5.3 Roddymoor, Crook, Co. Durham

Extensive species tnals have been laid out on this site and
nvestigations into the waterholding capacity, nutrient
retention, the development of organic content and crumb
structure as a result of maintenance techniques are under
way. The results of this work are reported in the appropriate
chapters of this volume The uses of topsoil, subsoil and
dnft maternal as well as farmyard manure as spoil additives

e being compared. Spoils left as surface materials include
grey, black and red shales, hot shale, slurry and red shale
mix, coke breeze and ash. This sort of experiment is
central to the work of the project and is repeated on most
sites, as are studies of vegetation (e.g. grass/legume) covers.
The species trials have been laid down for trees and shrubs
and include unrooted cutting trials.

3.5.4 Percy Pit, Newburn

A range of investigations on vegetation, soil development
and stability would have been undertaken on this site had
the work proceeded on the ground. One aspect which was
studied carefully in the design stage was a special approach
to the drainage of steeply sloping sites involving the creation
of low surface water channels, collecting water to prevent
the build up of large volume flows down the slopes, holding
the water to prevent excessive flooding at the lowest point
due to rapid concentration and releasing it to the main
drainage system at a rate which the system could accept.

The investigation, at the design stage, of the influence of the

heap in the broader landscape and approaches to its
remodelling, are design research topics dealt with at some
length elsewhere in this volume.

3.5.5 Haswell Colliery, Easington, Co. Durham

The development of this site, curtailed by acquisition
difficulties, would have afforded practical testing proposals
for optimum slope and aspect for agriculture. The site
would have provided a particular opportunity for the study
of the creation of heath type, Nardus stricta Erica flora

on areas to be used for picnicking and casual recreation.
This flora had developed over a number of years on certain
parts of the site. Both the speed of naturakand artificially
stimulated development and the suitability of the naturally
developing flora would have provided information of
value.

3.5.6 Big Waters, Seaton Burn, Northumberland

As originally proposed, this site has offered the chance to
plant a number of field trials of species suitable for wild
life habitat. This is the only particular line of research
within the compass of the project’s main objectives which
is specific to this one site. A large number of unrooted
cuttings have been included in these trials. The techniques
of working areas of burning shale and preventing the spread
of burning has been a particular practical problem.

3.5.7 Windynook, Whitehills, Felling, Co. Durham

This site (Fig.3.4) has provided particular difficulties of
acidity and salinity of the parent material. In addition to
the scientific interest, and the administrative difficulties
which this condition introduces, the study of earthmoving
calculation techniques has been particularly significant on
this site where a large volume of material has been regraded
on what is a relatively small area in compliance with
certain criteria for slopes and angles for use and mainten-
ance. The problems of surface water and deep under drain-
age, stability and erosion can also be examined in detail.

The problems of toxic shales and their treatment at this
site and at Big Waters are dealt with at some length in
Chapter 6, and will be the subject of continuing research
over a number of years.

28

3.5.8 Maria Colliery, Newburn, Northumberland

This small site, in the process of reclamation at the time of
writing, is to be returned to industry. Methods of providing
temporary grass cover at low cost on the varied spoils is
included though this work is not yet complete. Otherwise
no particular topics for research other than those common
to all sites, have been defined for this site.

3.5.9 Copperas Lane, Northumberland

At the time of writing, only preliminary investigations

and sketch plans have so far been undertaken, It is not
anticipated that any particular problems will be encounter-
ed on this small site, which is to be developed for casual
recreation and open space.

References

Atkinson, J. (1859) Ventilation of Mines.
North of England Institute of Mining
Engineers. Transactions. Vol. Vil Andrew Reid,
Newcastle upon Tyne, pp. 133-167

Dodds, M.H. (1930) A History of Northumberland
Vol. XIII Andrew Reid, Newcastle upon Tyne.
pp. 25-26.

Fordyce, W. (1857) The History and Antiquities of the
County Palatine of Durham. Vol. 2. A. Fullerton
& Co., Newcastle upon Tyne. pp. 360-62.

Hall, W.F. (1884) On the Haswell Mechanical Coal
Getter: an invention for working coal without
the aid of gun powder or other explosives.
North of England Institute of Mining and
Mechanical Engineers Transactions. Vol XXXII
A. Reid, Newcastle upon Tyne. pp. 37-59.

Page, W. (Ed) (1907) The Victoria History of the County
of Durham. Vol. 2. London,Constable. pp. 320 et seq.

Ceeeeeee eee n ence ee

Name of site Location

Climate Area

Visual description Soils Proposals

1. ‘Northbourne Park’
St. Anthony’s Site ‘B’
Newcastle upon Tyne,

St. Anthony’s
Point, Walker
Newcastle upon _ local

Open and 6.07 ha
exposed to (15.0 acres)

The northern Surface Developed as a river
boundary feature, material oriented park,
the railway, acts underlain allowing for more

Northumberland Tyne prevailing for a large part by glacial intensive use if this
wind westerly of its length as drift. is subsequently
along river a visual limit to Consists felt to be desirable.
valley also to the site, which ofa
cold east wind slopes south- mixture
in winter. ward to the of natural

Tyne ina soils and
formation soils
consisting dominated
broadly of four by introduced
terraces linked material -

by loamy clay.
embankments.

2. ‘Egerton Gardens’ Whitehouse A 1.17 ha A small area of Clay, over- To provide a robust

Newcastle upon Tyne, Road, prominent (2.9 acres) open space in a lain by design by the

Northumberland Paradise, position part of building development of

Newcastle upon in the Newcastle rubble, strong land forms
Tyne Tyne Valley undergoing chemical with a linear
on a favour- extensive waste feeling created by
able south change. Good and the arrangement of
facing slope. views across other contours and
Com paratively the Tyne debris. artificial platforms.
exposed to Valley and up Virtually
prevailing the Derwent no
winds down Valley. topsoil.
the valley.

Name of site Location Climate Area Visual description Soils Proposals
3. Roddymoor One mile Relatively 56ha Before Soils Agricultural land,
Colliery, Crook north west high (140 acres) reclamation derived with grazing of
Co. Durham of Crook altitude the site from stock, woodland on
of 183m consisted of boulder steep slopes and
(600 ft) the massive clay shelter belts along
and more pit heap, a overlaying the watercourse in
above sea dominant coal the flatter area.
level. element in measures.
Generally the whole Slurry
exposed valley land- ponds
though the scape, and occupied
main west- the associated a large
east valley colliery and area of
is coke plant the site.
comparatively working areas, Burnt and
sheltered. creating a unburnt
degenerate shale, coke
and depressing and ash.
area.
a
4. Percy Pit, West of Position 12.95 ha A conical Gravel Western end
Newburn, Lemington and (32 acres) heap within an workings incidental open
Northumberland aspect old dry gravel at space, possible
favourable, working at western development of an
sheltered west end of end, into artificial ski slope
from north site, and some which on the retained
east winds. low tips and a the pit pit heap material.
No danger flat area of heap Eastern end
of frost colliery yard at material industrial
pocketting. eastern end. was development.
There is also an tipped,
area of indicate
allotments. the
presence
of a bed
of river
gravel and
a resulting
light soil.
5. Haswell Colliery, South of Compara- 31.02 ha Much of the Some Sketch plans only
Easington, Haswell tively (76.66 acres) worst visual areas of prepared.
Co. Durham Village exposed, disturbance is natural Agricultural use
occupying created by the soil either as a single
a north/south opening up of remain small holding or
saddle in vertical shale at attached to
open country. faces by red northern — existing holdings.
143m (470 ft) shale operators. end of
above sea Established site where
level at highest areas of tipping did
point. vegetation, not occur.
where
undisturbed,
attractive and
extremely
interesting
botanically.
6. Big Waters, West of A.1 Occupies 45.32 ha Picturesque Derives Nature reserve and
Seaton Burn, at Six Mile a (112 acres) but much of from field study facilities
Northumberland Bridge shallow the land is boulder for the Northumber-
between depression without vege- clay over- land and Durham
Seaton Burn in the South tation and the laying Naturalists Trust.
and Wideopen East North- lake water and coal
umberland Seaton Burn are measure
Plain. Liable frequently rocks.
to drainage of discoloured; in Spread
cold air and particular the mixed burnt
frosting in burn has nasty and unburnt
still deposits on the shale appears
conditions. banks. not
particularly
hospitable
to plant
growth.

30

Name of site Location Climate Area Visual description Soils Proposals
7. Whitehills/ South and Highup 56ha Five distinct Limited Playing fields and
Heworth/Windynook east of andvery (14Q0acres) areas of natural interesting open
Felling Windynook exposed dereliction (with soils space for casual
and Felling from its a character- derived recreation.
north and istically typical from
east aspect. appearance sandstone.
It can be adjoining them). In some
assumed this Views to south parts a
high elevation and west are capping of
mitigates the restricted, but to boulder clay
effects of air the north and occurs. Burnt
pollution found east a complete and unburnt
elsewhere in panorama of shale, slurry,
this area. Tyneside from washery waste
the west side of and domestic
Newcastle to refuse in the
Tynemouth in quarry.
the east is visible Extensive areas
from numerous of fused shale.
places on the
site.
8. Maria Colliery West of Open and 4.45ha Small conical Gravelly _ Industrial
Throckley, Throckley/ exposed (11 acres) heap containing loam, development.
Newburn on Tyne, Westerhope to all winds. about 57,000m3 textured
Northumberland Road, a Cold air (75,000vd 3) brown
quarter of a drainage free, of unburned earth, and
mile north little evidence shale amongst unburnt shale.
of Throckley of serious low heaps of
atmospheric indeterminate
pollution. age now largely
vegetated. Over-
looking open
country of gently
undulating nature.
9. Copperas Lane At the Exposed 16ha An uneven and Limited Casual recreation
Scotswood, southern end to (40 acres) badly drained natural and public open
Newburn on Tyne, of Denton valley area of uncon- soils. space.
Northumberland Dene, west winds in trolled tipping Soils
of Newcastle the Tvne and brick waste developing
City boundary Valley, and to the north on tipped
heavy with steep banks material
atmospheric of colliery waste are of high
pollution. tip overlooking clay content.

the river to the
south and old clay
pit to the west.
Extensive views
across the river
and towards

Stella Power Station
and Percy Pit to the

west.

3

Chapter 4 Landform design

by M.F. Downing

While future land use is perhaps the dominant factor which
must be considered in the design of earth shaping on
reclamation sites, itis by no means the only constraint
which requires consideration. Some reclamation may in fact
take place when the future land use is as yet undetermined,
in which case the design must incorporate positive features
permitting the widest range of options for the future
development of the site. Where specific requirements are
the result of particular end uses, they should only be
carried out when they either do not preclude other end uses
or there is no possibility of a change of plans.

When discussing earth moving, the factors governing the
design approach can be classified broadly under four
headings.

(a) Economics

(b) Aesthetics

(c) Topographical factors, including surface drainage and
aspect etc.

(d) Functional requirements of land use.

It is unlikely that a given solution will be directed by only
one of these factors. On the other hand, the different
factors may frequently suggest contradictory solutions.
However, this classification method can be used to establish
some order in the setting down of the factors which limit
the design.

4.1 Economics

The influence of economic factors is felt at every stage of
the design process. A preliminary assessment of the
possibilities of a site will include careful attention to the
com parative costs of alternative methods of treatment. In
general terms, the selection of special solutions, when these
involve particularly expensive measures, will only be
undertaken when a clearly defined demand exists. It is
sometimes necessary to carry out simple exercises to test
the strength of such demands. For example at Percy Pit,
Newburn, there was a need for land industrial development.
It became obvious very quickly that to develop the whole
site for industrial purposes was likely to result in excessive
costs. A simple study sufficed to show that the topography
of the western portion of the site was such that, after
regrading, only half could be made available as a flat

area suitable for industrial development; the remaining
area consisted of steep banks, which would be

entirely non-productive and difficult to maintain. The need
for space for industry was not strong enough to justify such
extravagant use of land at the time and place of the
enquiry. That is not to say that such a step might not be
considered justified in other circumstances.

Except in specific cases where particularly strong demands
exist, economic factors play a significant role, not so
much in determining the overall form of the reclamation,
but in refining the effects of decisions based on aesthetics,

32

topography , and land use requirements, so that the
solution can be achieved at least cost. Again, no designer
can consider these other factors without appreciating
their cost implications, so cost consciousness may be said
to influence all aspects of the design approach, sometimes
at an almost subconscious level. At every design decision
stage the answer to two questions must be sought. The
first is ‘what is the cost of the solution proposed?’ The
second is, ‘is this the optimum return for the money
outlaid or will any increase in expenditure result in
significant improvements in the overall results?’ or
conversely, ‘will further financial reductions result

in limiting the potential of the site?’ The design solution
should always keep open as many of the development
options for the site as possible.

4.2 Aesthetics

The aesthetic factor is the next to be considered, and the
point must immediately be made that this is closely
linked to the other factors listed. Although the functional
and topographical requirements of a site design may
result in compromise with the original aesthetic purpose,
it is the visual aspect of landscape work which causes,

in the majority of cases, the most significant impact on
the greatest number of people. If this is a somewhat
limited reason for the development of subtle designs it is a
more than adequate justification for the avoidance of ill
proportioned and unsightly compositions.

4.2.1 Natural or geometric forms

The basic aesthetic decision which must be taken on each
site concerns the aesthetic ‘idiom’ which will govern the
design. The choice is between a design adopting naturalistic
forms which will blend into the natural topography of the
surrounding landscape and a consciously dominant
geometric or architectural form. This must depend largely
on the site and its environs. Hackett (1960) has suggested
that the natural landscape should be the dominant influence
in the design of new landforms, and arrives at the
conclusion that artificial or architectural forms are
acceptable only in the context of environment in which
man made forms dominate. A contradiction to this
statement is provided by the many historic examples of
landform design, showing most patently the hand of man,
which are to be found in settings of natural topography.
A number of such examples can be found in England
alone, notable among them being Silbury Hill and

Maiden Castle. Hackett later (1964) suggests three
principles governing the appearance of such artificial
earthworks whichmake them visually acceptable. These
may be summarised as:

(a) Containment within the topographical framework
(b) The use of simple forms resulting from primitive
methods.

(c) The relationship of earthworks to another
humanised feature, eg defensive earthworks following
the form of the city around which they were built.
The form of the city will of course be set out with
some regard to the topographical advantage to be
gained from its site.

Of these, the first two principles accept the dominance

of natural forms in a rural situation, the third offers a
justification for architectural or formal design elements
being acceptable in the context of an architectural
background. Perhaps a fourth principle should be added to
the three previously quoted when attempting to explain
the success of many obviously artificial earthworks which
are acceptable in natural surroundings. This is the
relationship of objects of similar scale.

4.2.2 Scale

For example while the form of a feature such as Silbury
Hill is totally foreign in the rural environment of
Wiltshire, the rightness of its scale within the surrounding
landscape makes it completely acceptable.

4.2.3 Antiquarianism

The acceptability of some historic examples such as the
Cerne Giant of Dorset or the White Horse of Uffington,
Wilts is enhanced because they have a readily
comprehensible shape and an obvious historic significance,
certainly for the amateur of landscape. Both these man
made features keep clearly within the topographical
framework, but both display an excellent scale relationship
with their respective, and similar, landscapes. Antiquarian-
ism as it affects the way in which people look at landscape
is one of the aspects dealt with in an amusing article by
Lowenthal and Price (1965), which also makes clear that
landscape tastes are not static for all time but subject to
subtle fluctuations of emphasis.

Two examples of the successful creation of landform
designs related to dominant artefacts are for the Oldbury
Power Station in Gloucestershire, and the nuclear research
stations at Harwell in Berkshire, both by Geoffrey
Jellicoe. The former the designer describes as geometric
and the latter organic (Jellicoe 1966). At Oldbury the
landform design achieved a compromise between the
pattern of the existing landscape, a humanised but
traditional pattern of the past, and the vast scale of the
geometry of the age of technology. In so doing it has
taken some of its form and its scale from each of these
elements. At Harwell, nature dominates in the flow of
the Berkshire downs, and the shaping of the land forms is
based on the conscious study of the natural forms. These
entirely different solutions by the same designer are

both acceptable because the eighteenth century
picturesque tradition, which is still the aesthetic

criterion by which landscape is judged today, demanded
the acceptance of the genius of the place.

4.2.4 Design aspirations

Jellicoe reminds the Peader of the aspirations towards the
creation of a self sufficient art form which must be the
landscape architect’s ideal, over and above the functional
requirements of good craftsmanship. This is related to the
effect on human beings which is, he says the ultimate
objective of all landscape design. He quotes observations

made by Barbara Hepworth (1952) who, speaking of the
response of visitors to the design and proportions of the
Piazza San Marco in Venice, said people “grouped
themselves in unconscious recognition of their importance
in relation to each other as human beings.” This

spiritual stimulation is the ultimate achievement of design
and one which is most poignantly desirable in areas of
industrial depression where landscape reclamation works
are predominantly carried out.

4.2.5 Application to research sites

The project has been concerned with three sites where
artificial forms have been positively accepted as the

correct idiom for landscape reclamation. These were
Northbourne Park (Newcastle), Egerton Gardens (Newcastle)
and Percy Pit (Newburn). Of the other sites, the proposals
for Roddymoor, Haswell Colliery and Big Waters involved
regrading to contours compatible with the natural
topography, while at Felling the design departs to some
extent from its naturalistic basis as a result of the require-
ments for playing fields which result in terracing. Maria
Colliery site is designed so that it and the adjoining land

are returned to the natural contours of the land before both
tipping and excavation for clay occurred, as nearly as

these can be ascertained.

The acceptance of geometric forms on the three sites first
mentioned, arises in each case from a different cause. At
Northbourne Park, the form of the site was dictated by
the existing strong terrace pattern resulting from
residential and industrial uses in the eighteenth and
nineteenth century, and from the tipping of ballast from
ships arriving in the Tyne. This was an established and
accepted part of the Tyne landscape and was retained with
only minor modifications where function or stability
factors made it necessary.

At Egerton Gardens, the urban setting, in an area where
care for the landscape could not be expected to be of a
high order, called for a design based on an artificial
arrangement of planes and embankments (Fig.4.1).
Such a design would reflect the vigour of the human
environment and at the same time resist the worst
depredations of vandalism.

Fig 4.1 Egerton Gardens: cardboard model prepared as a
design check.

33

The , t Percy Pit was one in which the aesthetic
s \\ ” S ctors. The site

ad ours, or it could
s was C ca pit heap

R ( S)t | ourse was
Pi vas S sted, but‘ there should be
\ seque eduction of scale
" hiss " cently in key witl

f the power station and the
wers i chimneys, the breadth of the Valley,

eht of the surrounding hills.”

i not find universal support and, particularly,

residents were strongly opposed to the retention of
nething which, to those who lived in its shadow, had a
physically overbearing presence and provided a
permanent reminder of past social evils: The design
ion proposed by the project involved the
e 1odelling of the heap to provide a feature which was

ificant in the valley landscape without overdominating

34

its immediate surrounds. A series of south-facing viewing
platforms were to be created commanding the valley
(Fig.4.2). It was possible to arrange the design in such a
way that the new artificial shape dominates only from the
valley bottom where, Laurie has suggested, it would be

in Keeping with other large scale industrial objects. From
some positions outside the immediate river valley, the
conical heap had appeared totally out of place and the
proposed regrading would have resulted in the creation of
apparently natural contours well matched to the large
scale of topography revealed in distant views along the
higher slopes of the Tyne valley in this area. The early
studies made into the influence of the heap in the Tyne
valley and the neighbourhood are discussed in greater
detail in Chapter 13.

4.3 Topographical factors

Aside from the influence that topography exercises on the
design aesthetic, which has already been discussed, it plays

Z

SE SI se

Ny

tS

va
7

es eee oo ee

Fig 4.2 Percy Pit: plan of reclamation proposals.

SSS

s

a significant part in deciding the disposition of regraded
material. It is essential to establish a healthy new landscape
over the reclaimed area and this must be done so that the
ecological balance of adjoining and otherwise inter-
dependent areas is not disturbed.

4.3.1 Drainage

The designer must therefore pay attention to the watershed
characteristics of the area to be reclaimed, and this should
include detailed drainage considerations.

It is also necessary to consider the interior measures for
the safeguarding of such areas in the event of adverse
weather conditions during the operations period and while
the site is becoming established. Many of the problems
which Curtis (1969) has shown to result from strip
mining in Kentucky,U.S.A., are commonly found on
disturbed land particularly when reclamation of mining
waste is in progress. Thus, operational land and land
awaiting revegetational cover is subject to accelerated

KEY
Je
ae. > opiainal CONTOURS
B----" > peoposen new LEVELS
60 PROPOSED 16'0" STANDARD TREES

EXISTING SHRUBS
PROPOSED SHRUBS

ci

ro) 25 50 m(160 ft )

runoff and erosion with resultant turbidity in natural
water-courses, silting up of basins, and in extreme cases
gully erosion in existing stream beds.

4.3.2 Water quality effects on adjoining land

In addition to the effect of quantities of water, the
quality of water emanating from reclamation areas is an
aspect that should be carefully considered when natural
drainage systems are involved. Downstream sections of
water catchment areas can be seriously affected by the
drainage of polluted water from strip mining or the
deposition of spoil. In this country, the majority of this
kind of dereliction occurs in close proximity to centres of
population and industry, and either the effluent is taken
into piped sewage systems or it is discharged into water-
courses already heavily polluted by other industrial
effluents. Where water quality is politically considered
important, often the only solution available is to pipe the
effluent away from the locality to prevent it from entering
the natural drainage system.

4.3.3 Free drainage

The foregoing assumes attention to details of topography
which ensures that the reclaimed landscape will drain
adequately and that there are no areas where water will
stand in storm conditions, unless this is by design, and no
parts of the site are excessively damp. This involves
ensuring that the design allows the free passage of water
down and through or away from the site into the drainage
system of the area, whether it be a natural stream and river
drainage pattern or a piped sewer system.

4.3.4 ‘Water table’

The behaviour of a soil ‘water table’ is dependent on a
number of factors - the topography, the type of soil, and
the volume and intensity of precipitation according to the
time of year. The regrading of pit heap areas is liable to
have an effect on the watertable of the adjoining land and
this can be particularly significant where the natural
watertable of the area is high in relation to the surface of
the ground. Any such possible alteration to the water-
table and its consequences must be carefully studied before
any regrading takes place. This is particularly important in
relation to standing timber of any size. The conditions at
the surface of regraded material will also be significant
since the porosity of the ground surface will affect the
percolation of water into the soil, affecting both water
table level and subsequently the water availability in
times of comparative drought.

4.3.5 Ground water movement

There are circumstances in which it is possible that a
reduction in natural ground levels to form an even grade
with opencast mine waste may result in the creation of a
new springline, where the watertable has been artificially
heldup by an impervious stratum. Similar conditions can
occur when waste material is laid down on impervious
strata. The flow of water will follow the falls of the
natural ground and a spring line is likely to develop
along the lowest part of the deposited material. A
situation such as this is one requiring extremely careful
investigation and a sound knowledge of the engineering
principles of the design of earth structures to ensure that

35

in

a stable situation is created (Tschebotarioff 1951, Krynine
& Judd 1957, Capper & Cassie 1954). The same careful
attention is necessary for the treatment of natural spring
lines or even water courses likely to be covered over by

fill material. It can hardly be necessary, after the lesson
of Aberfan, to underline the dangers of flow slides
resulting where deposition occurs on sloping sites
undermined by ground water.

4.3.6 Frost drainage

The consideration of drainage extends to ensuring, as far as
possible, the unimpeded drainage of cold air on the site,
regardless of the afteruse. Thus undrained hollows or the
placing of vegetation screens where cold air flows might

be impeded must be avoided.

4.3.7 Shelter

Consideration, and the solution, of this problem will
depend to some extent on the specific afteruse intended.
Also affected by the afteruse will be the consideration
of shelter provision, though this is also determined to a
large extent by the dominant surrounding topography
(Cabo 1965). Shelter belts can be used to diminish the
effect of wind on soil, both in its cooling effect and by
wind erosion of soil particles in ploughed arable land,
with a resultant improvement in the microclimate of the
area of the shelter belt. In addition we now have a
reasonable understanding of the effects of shelter belts on
snow in terms of shelter and drifting (Caborn 1967), and
the possibilities of planting to divert frost and cold air
drainage from areas requiring special protection. The
creation of new landforms offers unique possibilities of
combining favourable arrangements of ground formation
with shelter planting to create ideal climate situations.
This design work is influenced by the framework of the
existing topography and its consequent local climatic
variations.

4.3.8 Engineering requirements

The critical structural requirements of earth banks and
similar structures only enter the scope of topographical

or functional factors as here defined when either

aesthetic decisions, or the functional requirements of

land use,dictate the creation of steep banks and sharp
angles. It is nevertheless important that the construction
of new features out of deposited material must be
structurally stable, and this involves investigation of the
substrata and its relationship to ground water as previously
indicated. It also involves ensuring that the surfaces of
materials are stable which means that the angle of repose
of the material must not be exceeded; on those sites where
there is a large clay fragment in the shale, care must be
taken to guard against rotational slip conditions developing
(BSI Earthworks 1959). In fact the design usually
formulated for regrading according to natural contours
results in slopes very well below the structurally acceptable
limits. The steepness of slopes is more usually dictated

by other factors, the establishment of vegetation and
minimising of slope erosion for example, or the economic
maintenance of embankments which require slopes well
below the critical structural level.

4.3.9 Application to research sites

The interaction of the dominant topography and the
land use requirements of sites is demonstrated in section

36

5.4.7 where the application of both aspects to the
research site is discussed.

4.4 Functional requirements of land use

The design of areas of regraded colliery waste material

may be undertaken with any one of a number of end uses -
in mind. The most desirable end use for a site within

a particular area may not have been determined. The
possibility must be allowed for changing circumstances
between the time of reclamation and subsequent site
development resulting in changed land use requirements.

This presents two alternative possibilities as design
approaches. The first as previously discussed is the
creation of a site which has characteristics enabling it to be
used for a number of purposes with a reasonably high
degree of efficiency and convenience, while the second
tailors the new landform and design details to one particular
use, with the likely result that its adaptability is reduced.
Before these extremes are reached there are anumber of
factors general to many, if not all, likely afteruses which
need to be taken into consideration. It should be under-
lined here that the discussion refers to the climatic
situation of the north east of England, and the range of
afteruses which are possible in this climate and in the

soils to be found here. Some limitations are also imposed
as a result of human tradition and economics which
dictate the choice of afteruse to conform with the pattern
of development of an area. Investigation of nonconforming
uses might well suggest that these could be established
satisfactorily and such investigations should perhaps be
encouraged. Except in those cases where an industrial,
housing, or similar high density use is proposed for a site,
it can be assumed that what is required is to create the
best possible conditions to support plant growth, as this
both indicates and is conducive to the development of
landscape health. Buckman and Brady (1960) list 6

factors influencing plant growth as:

(a) Light

(b) Mechanical Support
(c) Heat

(d) Air

(e) Water

(f) Nutrients

It is therefore desirable to attain in all site developments
the best conditions possible for plant growth under the
listed headings.

The study of these factors supports the general conclusion
that better, and particularly earlier, growth is achieved
from plants growing on south facing slopes as a result of
longer and more intensive exposure to sunlight. The
advantages of this improved growth are most likely to be
found with land in agricultural use, either pasture or
arable, and particularly with horticultural crops. Soils
which, because of favourable aspect, offer ‘early bite’

are much favoured by farmers, and standard
recommendations for the siting of orchards emphasise the
advantage of a south and south west aspect. In addition
the increased warmth of such an aspect improves the
environment for human occupation for both industry and
habitation.

In the case of forestry on shale, on the contrary, experience
has shown that with young trees better growth occurs on

north facing slopes, for reasons thought to be connected
with soil moisture tension (Richardson 1967).

Attention to aspect is particularly important when
dealing with areas intended for sitting, walking and
picnicking where the landform is frequently used to
provide suitable sites in full sun and out of the wind for
casual family and social gatherings. Other more specialist
landforms can be developed for theatrical and musical
presentations and arenas for sport where the raised sides
can be used to accommodate the audience. The develop-
ment of this type of feature in the north east of England
calls for attention to the maximum provision of shelter and
the optimum use of sunlight which implies careful
consideration of aspect in the design.

4.4.5 Angle of slope

Detailed land form design is governed by slope angles and
direction which are dictated by the nature of the spoil
material and by the way the site is to be used. A theoretical
optimum angle of slope is that angle at which adequate
surface drainage occurs without any erosion of soil
particles. This occurs at an angle of between 1:40 to 1:50
dependent on soil or spoil type. At angles above this
erosion begins to assume significant proportions, while
below it natural drainage does not take place. In field
conditions the requirements of end uses usually dictate
that this slope should be varied, necessitating the employ-
ment of either artificial drainage or measures to combat
excessive erosion. Where reclaimed land is to be used for
pasture, giving a comparatively low return on capital
expenditure, the expense of providing field drainage is
frequently considered unjustified and slopes of

between 1:30 and 1:40 are usually employed. These have
been successful on the research project. Even at these
slopes, without careful management, there is a danger that
cattle will poach the ground, which can cause particular
problems in the poorly structured ‘soil’ of reclaimed land.
Where land is to be used for playing fields a shallower
slope must be achieved to provide a surface which is
sufficiently flat for ball games. This means that an
artificial drainage pattern must be installed to ensure that
excess water is taken away from the surface so that there
is a good growth of grass and the playing surface is in a
suitable condition for use in the wintertime, when the
heaviest use is generally to be expected.

On the majority of sites the large volume of material to be
disposed necessitates the construction of some
embankments. In open spaces for casual recreation,
picnicking and nature study, the design may incorporate
small hills.

The design of such features must be undertaken within
certain limitations of slope. Experience in Durham has
suggested that an angle of slope greater than 1:5 to 1:6
should not normally be adopted, as anything greater than
this will not easily merge into the natural topography

and will create problems of surface water drainage. Where
a downward slope of this high angle approaches the
boundary of a site, N has been the practice to reduce it

to 1:20 so that the rate of flow of surface water is reduced.
This helps the cut off ditches and drains to work efficiently
and prevents flooding of the adjoining land. These points
are discussed further in Chapter 7.

In certain cases it may be desirable to create slopes
Steeper than 1:5 to 1:6, and this may be possible in

certain circumstances by the use of special techniques,
some of which are discussed in Chapter 6. Although

there are many examples of the satisfactory establishment
of steep slopes on roadsides and in similar situations, it
must be remembered that shales have their own particular
problems of stability and chemical content. In general steep
slopes need to be planted to maintain stability and tree
planting undertaken to provide shelter and to eliminate or
rather reduce the maintenance liability. It is important
that species are selected with a light canopy which will not
smother the shrub and ground cover layers necessary to
maintain the surface stability of the slope. For certain
special uses, notably artificial ski slopes, steeper slopes

up to 1:2% are required, and these can be adopted in

the knowledge that the artificial cover afforded by the
skiing surface will provide some stabilization of the soil.

The operating capabilities of machinery may be a more
realistic limiting factor than the visual requirements on
agricultural land. Where agricultural machines are to
operate efficiently an angle of slope not greater than 1:10
should be adopted. It is possible to make use of grass
maintenance equipment which will operate on short
slopes as steep as 1:1. The machine which can do this is
a flail which can cut up or down a short slope from a
tractor with a long arm standing on flat or near flat
ground. The situations in which this type of equipment
can be operated are obviously limited, and their use

is only warranted where amenity overrides economic
considerations. The use of grass cutters operating on the
‘hovercraft’ principle are affected by the same limitations.
They can be operated on slopes of 1:2. The steepest
slope acceptable for reasonably efficient operation of
standard grass cutting equipments is 1:34, well below
the angle of repose of engineering soils other than organic
soils or soils in an exceptionally wet condition (BS C.P.
2003 1959 Table 3). This will be reasonably stable so
long as the surface is held by some means, though this
sort of slope can only be justified for small areas and
where costly maintenance can be accepted. Even where
forestry is to be undertaken on these slopes they may
need special stabilising techniques and should in general
be kept to a minimum. Particular precautions in the form
of cut off drains need to be taken to prevent the
flooding or silting of land at the bottom of slopes, but
the expenditure and trouble involved is frequently well
repaid by the greater area of land with favourable

aspect which can consequently be developed.

4.4.6 Nature of material

Reference has been made to the nature of materials

met on areas of colliery waste and their effects on the
adjoining land, and on the watershed in which they exert
their influence. The very varied chemical and physical
properties of shale found on all coal sites may have a
critical effect on decisions relating to the finished formations
and the land use of individual sites. Some assessment of
the material and its potential must be made at an early
planning stage, before any proposals for land use or final
landform. Details of the behaviour of various materials in
relation to plant growth are given in Chapter 8. In
addition to these limitations the liability to combustion in
the material, dependent on combustible content, sulphides
and air, will affect the suitability of the material, and thus
the site, for certain uses.

37

Development of colliery land for industrial or housing
SES S » undertaken only on heaps of
al deriv more efficient washery
The difficulties of assessing the contents of heaps,
ature irements, and special
s required to prevent combustion are discussed
greater length in Chapter 6. It must however be said
e that until further research can be undertaken into
s aspect of the behaviour of colliery waste material, the
t stringent precautions should be observed
The wa which the nature of the shale may dictate the
1 andform design has already been mentioned. Some
iaterial may need to be buried and other material used as
iressing. The nature of some spoils may be so

lent to plant life, as to make their exposure
ndesirable and this must be ascertained by investigations

before any designing is undertaken. Similarly the presence

large areas of fused material, in which single blocks

can be many cubic metres in volume, presents problems

of design (Fig.4.3). It is often not possible to break

this material down, it is not susceptible to explosives, and

it is frequently difficult to move by reason of its size.

Consequently the design has to be manipulated to leave

such material in place, with the limitations this imposes.

The nature of material on site also affects the cost of
earth moving operations, and this may be significant in
determining in some cases the final landform of any
design. Simple operations which can be undertaken with
one machine.e.g. a scraper, working homogeneous material
varying from loam to gravel particle size, are the ideal
processes for efficient low cost reclamation works. The
presence of wet material, slurry, fused material, or hot
material, all of which are common in pit refuse, introduce
complexities which slow down the operational cycle

or involve additional machinery and handling, and
increase costs. Often economics can dictate that such
difficult materials should be left undisturbed.

4.4.7 Economic operation of plant

Wherever possible the cost factor also enters into the
detailed design of new land form. A design which can be
completely carried out using a scraper, without any
ancillary equipment, to form embankments for example,

will be cheaper to carry out than one in which additional
machinery is required to complete the final shaping and
placing of material. Hackett (1964) suggested that designs
involving undulating landform are less expensive to carry
out than designs consisting of geometric terracing , and

that on any site over 0.1 ha (% acre) the cost differential

of different design approaches is significant. Landform
designs should therefore take account of the maximum
operational angles, the turning circle, and performance data
of the type of machine which, from its method of operation
and size, is thought to be the most appropriate for the site
to be developed.

It is evident that any aspect of the design which causes
any check in the free operational flow of the earthmoving
process, or causes the introduction of special apparatus or
a special process, must have a particular significance in the
final design concept for it to be allowed to remain on
economic grounds alone.

4.4.8 Application to research sites

The sites under treatment by the project offer a number of
examples of the way in which the topographical framework
of the site, and the proposed land use, control the design
of earth shaping. Northbourne Park, Newcastle, can be
quickly dismissed, as the earth shaping was a minor

feature in an already strongly defined landform which
suited admirably the recreational purposes related to

river activities, for which the park is intended to cater. The
site was one of the early schemes undertaken within the
Project and did not involve any colliery waste. The
proposal to leave the landform as existing and use trees
and shrubs to further stabilise the bariks (1:1% gradient),
was not at first received kindly by the Ministry of Housing
and Local Government, and at one stage in the proceedings,
the Inspector suggested regrading over the whole area. An
exercise was carried out and this showed an average gradient
of 1:4 would result and hence the area would be difficult
to use for its intended purpose of public open space and
also be difficult to maintain. It was finally agreed that by
leaving the terraces and slopes in their present landform,
areas of useable open space would be left. The use of

trees and shrubs as acceptable reclamation elements for

the stabilisation of steep slopes was eventually accepted

for this site.

Fig 4.3 Felling: conical heap and lumps of fused burned shale.

38

ond Nee

—

_At Egerton Gardens, the general topography of the area
enabled the development of the site to the best functional

advantages. The north slopes of the Tyne Valley at this
point rise at an angle of approximately 1:10. Topography,
function and aesthetics all combined to suggest a design
with a series of platforms separated by steep banks. South
facing sitting areas, with views across the valley are
sheltered by being tucked into the banks. The site is free
draining, discharging into the municipal sewers, and there
were no problems of inhospitable parent material. The
bank along the southern part of the site is at an angle of
about 1:2. It has been thickly planted, and seeded with
rough grass. An experiment to compare the merits of
bitumen spraying and hydromulch techniques was
unfortunately invalidated as a result of a contractor’s error,
as previously indicated, but the establishment of vegetation
on slopes has been successful, except where limited

human interference has occurred. An experiment making use
of P.V.A. (poly vinyl acetate) as a method of covering a
section of slope after seeding resulted in poor germination
and growth which it has not been possible to explain
satisfactorily, though it has been used successfully
elsewhere. The angle of slope of the platforms is 1:50 to
1:60 and this appears to drain freely over the limited

areas though it is assisted by the presence of some cut off
drains at the base of embankments.

Percy Pit site (Fig.4.3) involved a design which for the

heap area combined one artificial aspect with a naturalistic
one, as has already been shown in Chapter 3. The use of
this part of the site for open space providing sheltered
viewing platforms overlooking the Tyne valley, dictated
the form of the design. Drainage of the site introduced
some problems discussed further in Chapter 7, but as the
site was drained into the main sewer system, no dangers

of watercourse pollution arose. The angles of slope adopted
in the design were well below those critical for slope
stability, though sufficiently steep to necessitate the
provision of special open channel cut off drains fo collect
and hold storm water in severe cases until it could be
carried away at the capacity of the sewers. The average
slope was in the region of 1:7 to 1:9, while in one sector
the provision of an artificial ski slope resulted in steeper
angles, approximately 1:5 being proposed (Downing 1968).

The eastern sector of the site, subject to com paratively
minor regrading to provide two almost flat terraces for
industrial development, was entirely dominated by
functional requirements. Industrialists generally require
flat sites for the development of factories and

regrading for this purpose should obey these demands.
Where some delay may occur between reclamation and
development it may be necessary to grade to a slope of the
order of 1:70 so that some drainage of surface water

will occur naturally. This was carried out in the Percy

Pit designs; obviously temporary tile drainage was
unjustified, but some way of limiting standing water was
also called for. It was also important to minimise the
excavation required for later development. Hence the
slope was selected to give run off of surface water
without excessive regrading at the industrial development
Stage.

At Haswell Colliery, the design was dictated by the

fincttonat requirements of agricultural pasture, but this
has to be carefully combined with the topography of the
site and neighbourhood. The site is in a watershed

position, between streams draining to the west and east.
The shale has been deposited for many years and there
was little to suggest that surface water leaching through
the site would result in watercourse pollution. Detailed
investigations of this aspect were not completed due to the
cessation of design work for the site. The position of the
main bulk of material enabled the development of a
small low hill with a long southerly slope at an angle of
1:30 suitable for grazing land without underdrainage
(Figs 4.4a and 4.4b). This would have enabled the site
to be drained naturally into the two existing watercourses
and resulted in a steep northerly slope on which shelter
belt treeplanting would have been established. The
higher areas, being more freely drained, were expected
to provide good pasture throughout the year. Some
parts more nearly at the surrounding ground level were
expected to provide more lush summer pasture, but to
be less suitable for winter use. Some form of mulch to
maintain surface moisture and prevent excessive
temperatures during the establishment of grass would
have been included on southerly slopes.

At Roddymoor the design proposals were predominantly
influenced by the topography of the area: the major glacial
valley divided into a series of small stream valleys, and

a north-south and a west-east valley system united within
the site area. The maintenance of this natural drainage
pattern was a prime consideration in the design work and
this has been extended into the adjoining National Coal
Board opencast area whose restoration will maintain this
feature, returning the whole area to a simulation of the
natural drainage pattern. The proposed use of the land was
for agriculture, and this involved obtaining the best southerly
aspect for the largest possible area, leaving northern slopes
of 1:3 to 1:4 for shelter belt planting. The angle of slope
on areas of pasture has varied between 1:30 to 1:10
resulting from the grading down of the main heap toa
gentle rounded hill formation. The drainage of the site is
into the natural stream pattern of the area and though
some pollution downstream has developed, no serious
complaints have been received. Some of the damage may
be attributable to the excavation of material on the
opencast site which has not been so long exposed to
weathering as that of the reclaimed area. One example of
the influence of site material on the-course of the design
was the case of the slurry material which had to be dug
out and spread in thin layers. This involved using light
machines, constructing a red shale haul road and covering
the spread slurry with 0.75 m (2 ft 6 in) red shale.

It is interesting to note that at Roddymoor the farmer
has selected the land with a south westerly aspect in the
face of the prevailing wind in this locality as the most
suitable part of the site on which to dry a crop of hay
Other aspects of the site are apparently suitable for grass
silage, except where the uneven settlement of the ground,
due principally to burning material below the surface,
makes the use of machinery impractical. On some parts of
the land till erosion has resulted in an uneven surface
which inconveniences the operation of machinery.

The Seaton Burn, Big Waters site developed from a
mining flash in the typically flat glacial plain of south-east
Northumberland. The site is enclosed by shallow ridge
lines to north and south. The Hartley Burn flows from the
south west into the flash area pond. The watertable is high
and this, coupled with the extremely shallow gradients

39

/

|
eee
YW
/) G
Se ee

\
—_
, ‘
pas

‘>

yO ORIGINAL CONTOURS,
\ “nee 7s ggg PROPOSED NEW LEVEL

SEMI MATURE TREES

- Aebtetbd er —ISTING SHRUBS

50 m(160ft)

Fig. 4.4 (a and b) Haswell Colliery: plans for reclamation proposals.

on site, makes it very wet. The site generally falls towards
the burn and the pond at gradients between 1:36 and 1:250.
The conditions prevailing before reclamation had resulted
in the development of a fauna population of considerable
interest, and the high watertable related to the lake level
is being maintained so that the site develops as an area of
interest to naturalists. The regrading of the eastern part
of the site to form a low hill with shallow slopes rising

6 m (20 ft) above the level of the lake, fits in with the
gentle contours of the area and provides well drained
pasture land. The lake glimpsed behind this new hill will

40

provide an interesting scenic incident on the new
Wideopen By-Pass motorway. A portion of reclaimed land
on the eastern side of the motorway will be devoted to
forestry planting to screen the backyards of Wideopen.

The Windynook site at Felling comprises several separate
and distinct areas. As previously stated the attempt here
has been to echo the natural character of the landscape of
the area, though in some parts the development of areas
suitable for playing fields has resulted in some dilution

of the design ideal. Drainage of the site is entirely to the

KEY
PP ORIGINAL ConTOUms

S wags PROPOREO Naw LEVELS

~-?

R

DORR 5 Ro
5 2 5Om a60rt)

Stat MATURE TeEEs

EXISTING, |ROAD

existing piped mains and the elevated position of the site
means that surface water is easily and rapidly dispersed.
Minor damp areas of low lying ground have been identified
but these can be drained without difficulty. Some
attempts have been made to create shelter for parts of the
Windynook Quarry and Whitehouse Farm areas by
mounding of spoil on the north sides of these sites. This
will be reinforced by treeplanting on the northern slopes.
The Windynook Quarry area is to provide open space for
casual recreation and this involves sheltered south facing
areas of gently sloping land at an angle (1:30 approx.)

TO BE ; [REMOVED -’

&

ee el oe

£

which will drain freely over the surface. The adjoining
washery material area is to be reduced to original ground
level for speculative housing development. The northerly
aspect and the angle of slope (1:10 to 1:12) however
render it somewhat short of the ideal for housing
development. Both the Heworth Colliery Site and the
Whitehouse Farm area are required as future playing
field areas. In the former case, the topography prevents
the achievement of a southerly aspect, though this is
attained on the latter site. The National Playing Fields
Association's recommendations for the slopes of winter

41

playing surfaces include ideal gradients of 1:60 to 1:80
with the steepest maximum desirable slope in any direction
given at 1:60(Gooch 1963). On the Felling site the

lateral falls have been designed at 1:10 which, with
underdrainage on reasonably permeable shale, should

result in a serviceable surface in most conditions.

At Maria Colliery the functional requirements of the use
of the main site for industrial purposes, and the regrading
of the pit material to a reconstruction of the original
ground level of the clay pit, combine the functional and
topographical aspects once more. The site is one where
drainage is simple and there were no problems of aspect or
steep slopes.

The design for Copperas Lane is not yet sufficiently far
advanced for comments to be made on the proposals.

4.5 Conclusion

The general conclusion suggested at the beginning of this
chapter was that besides afteruse, both aesthetic idioms and
topographical features must play a part in governing the
design of the site. Beyond this it is difficult to draw out
any general conclusions other than the truisms that

(a) Landform and runoff are inseparable in design
problems.

(b) Landform design is a major influence in the
development of the pattern of vegetation on a site.

(c) The nature of the material is an important factor in
design.

Some sites can be reclaimed with a multi purpose potential,
others have their dominant use ineradicably stamped upon
them. The process of design is different in every case. The
common denominator is the need to work with the site
rather than against it, either suppressing undesirable
characteristics where this is possible, or emphasising its
strong features. The new topography should not limit the
aesthetic or functional development of the site, neither
should afteruse or aesthetics impose on topography.

J.O. Simonds’(1961) statement that “for every site there

is an ideal use. For every use there is an ideal site” indicates
the need to study the qualities of each site and make one’
decision on landuse only after gaining information from
site or landscape surveys. Following this course will

result in designs which are visually acceptable, simply and
economically executed, and functionally efficient.

References

British Standards Institute (1959) Earthworks. B.S. Code
of Practice No. C.P. 2003 Section 4. Embankments.
pp. 34-44. B.S.I. London.

Buckman and Brady (1960) Nature and Properties of Soil.
6th ed. Macmillan.

Caborn, J.M. (1965) Shelter Belts and Windbreaks. Faber
and Faber. London.

Caborn, J.M. (1967) Planting against snow and winds.
Roads in the Landscape Conference. M.O.T.
British Roads, Keele University.

42

Capper, P.L. and Cassie W. Fisher (1854) The Mechanics
of Engineering Soils. 2nd ed. E. & F. N. Spon.,
London.

Challenger, S. (1967) The effects of air pollution on tree
growth - a literature survey. Newcastle upon Tyne.

Curtis, W.R. (1969) The effects of strip mining on the
hydrology of a small mountain watershed. Proc. In..
Symp. on Ecology and Vegetation of Drastically
Disturbed Area.

Downing, M.F. (1968) Artificial Ski Slope Study, Percy Pit,
Newburn on Tyne. University of Newcastle upon
Tyne Landscape Reclamation Research Project.

Gooch, R.B. (1963) Selection and Layout of Land for
Playing Fields and Playgrounds. 2nd ed. N.P.F.A.,
London.

Hackett, B. (1960) Basic Design in Land Form. Journal
of I.L.A. No. 49, pp. 7-9.

Hackett, B. (1964) Land Modelling. Public Works and
Municipal Service Conference.

Hackett, B. (1964) Landform Design and Cost Factors.
Landscape Architecture. Vol. 54, pp. 273-275.

Hepworth, B.(1952) Carvings and Drawings. Lund
Humphries and Co. Ltd., Chapter 6.

Jellicoe, G. (1966) Studies in Landscape Design. Vol. Il.
Oxford.

Krynine, D.P. and Judc, W.R. (1957) Principles of
Engineering Geology and Geotechnics. McGraw Hill,
London. pp. 591-635.

Lake, J.R. (1968) Unburnt Colliery Shale - Its possible
use as roadfill material. Road Research Laboratory
M.O.T. Crowthorne.

Laurie, I.C. (1965) Tyne Landscape. Consultants Report.
Unpublished.

Lowenthal and Price (1965) English Landscape Tastes.
Geographical Review. Vol. IV, No. 2. pp. 186-222.
American Geographical Society, N.Y.

Richardson, J. A. and Greenwood, E.F. (1967) Soil
moisture tension in relation to plant colonisation of
pit heaps. Proceedings of the University of
Newcastle upon Tyne Philosophical Society.

Vol. 1, No. 9, pp. 129-136.

Simonds, J.O. (1961) Landscape Architecture. lliffe Books,
London.

Stacy (1957) Increase in dry weight of plants related to
temperature. Agronomy Journal.

Stoughton, R. H. (1955) Light and Plant Growth.
R.H.S. Journal.

Tschebotarioff, G.P. (1951) Soil Mechanics, Foundations
and Earth Structures. McGraw Hill, London.
pp. 169-199.

Underwood, C.V. (1967) Mechanical Grass Maintenance.
Roads in the Landscape Conference. M.O.T.
British Roads, Keele University.

Chapter 5 Earthworks: outline of methods
used within the project

by M.F. Downing

5.1 Introduction

The foregoing chapter has attempted to indicate the factors
which influence the design of earth work operations in the
creation of a new landform design. It is now necessary to
look at some of the techniques adopted in the project in the
preparation of schemes for design, and at some methods
used by others. There is considerable divergence in the
methods adopted in the field of landscape reclamation. This
extends to the degree of accuracy and detail considered
desirable for survey and for design, for calculation of
quantities, and even to the scale at which design work is to
be undertaken. Some general discussion on this aspect may
well be appropriate here as an introduction to the more
detailed information in subsequent sections. The degree of
accuracy and detail adopted for the survey and calculation
should be the highest possible taking into consideration the
inherent limitations in precision of site operations. If
operations on site are to be undertaken by earthmoving
machinery which is vertically accurate only to 0.1 m, there
is obviously no advantage in calculating everything to

0.01 m. Additionally, it is well known that the calculation
of very precise quantities and very accurate measurements
of height and area in plan often involves a greatly

increased outlay in terms of man power, and therefore
cost, than a survey to less rigorous standards. The
limitations of machinery operating on site are not the only
factors apart from increased survey costs, which limit

the degree of accuracy and detail at which it is necessary

to operate for design purposes. Everyone experienced in the
commonly used methods of plan reproduction is aware of
the limited reliability that can be placed on the accuracy
of these documents. Whyte (1969) suggests that since it

is difficult to plot on paper actual measurements smaller
than 0.2 mm it is pointless to measure more accurately in
scale on the ground. At scale 1:500, 0.2 mm represents

0.1 m so this may be adopted as the appropriate level of
accuracy providing this is applied to any dimension and no
cumulative error ensues. This, of course, does not allow for
errors arising from shrinkage, expansion etc. of paper,
negatives, and copy negatives.

5.2 Survey

The gathering of survey information for derelict land
reclamation follows the common pattern adopted before
major designs can be undertaken. It includes the
topography of the site and its adjoining area, the significant
landscape features on and off site including vegetation,
geology, soil types or types of deposited materials,
drainage - in short all the factors which have already been
outlined in Chapter 4 as influencing landform design. In
addition to this, the presence of services, rights of way,

or easements over the site obviously must be established and
recorded. The future use of a site is determined to a large

degree by its existing features, but these are not the only
factors, nor in the case of derelict pit heap landscapes
when a complete revision of the topography is due to take
place, are these as important as they would be on a more
normal site. A great number of social or economic
planning considerations also dictate the land use decisions,
and these can outweigh the landscape factors with the
result that the proposed land use may be less than ideal
from a landscape point of view.

5.2.1 Topographical survey

The delineation of the topographical features of a site is the
most important basic requirement for the carrying out of

a design. This information may be obtained either from a
team of surveyors working on the ground or by photo-
grammetric methods of aerial survey. Both methods are
liable to some inaccuracy. Ground methods of surveying
are based on selecting average readings, whether in triangula-
tion or in the mapping of contours through a grid of
levels, whilst photogrammetry is subject to scale inaccuracy
in the plan preparation stage. But a very high degree of
accuracy is not necessary since this would exceed the
operating accuracy of the contract works. For further
discussion of the “needless refinements of figures” see
Clark (1949). It will be obvious that for small sites, or
those with low rates of topographical variation, surveying
can be undertaken by a team of field surveyors using
triangulation, or more rarely plane table methods and

grids of spot levels. The use of a grid with the individual
spot level on the grid representing an average height of

the area of land surrounding it introduces the element of
averaging already mentioned. The accuracy of this method
obviously depends on the size of the grid selected and this
is influenced by the rate of change in topography and
minor irregularities of the land surface. Where there are
very large changes in gradient and the surface is

extremely broken, a close grid will be necessary to

achieve even an approximation of the topography. This
will involve many changes of station and tedious operating
over steeply sloping terrain. The smallest grid likely to

be adopted on limited sites with complex surface
characteristics is 10 m square (imperial measure used

25 ft). For one hectare (2.47 acres) this would involve
taking 1000 spot levels, and even then the accuracy of
interpolated contours, or of the average height assumption,
is highly questionable. There are many derelict sites where
the changes in level which may occur in a distance of

10 m (33 ft) could make the spot level chosen totally
unrepresentative. Where this situation occurs only locally,
it is possible to take intermediate levels, but this is

plainly not conceivable all over a site where a reduction to a
5 m square grid would quadruple the number of readings
while only marginally increasing the accuracy of the

survey. These limitations apply no matter what method of

43

assessing levels is chosen, since there is an inherent plus or
minus error in photogrammetry, and because of this
extreme sophistication of calculation is invalid.

On larger sites, 50 ha (125 acres) or more, a grid of 50m
squares (equated with 150 ft) may be adopted, this being
the maximum acceptable grid size even on land with

little topographical variation, and would involve over 300
grid point spot levels. If a grid of 25 m (82.5 ft) is used
(which is a useful mean for grids on all but the largest sites,
but see Fig.5.3) this will involve taking over 650 individual
readings on a site of 50 ha (125 acres). The marginal
advantage in accuracy of a 20 m (66 ft) grid is outweighed
by the additional readings necessary ; for a 50 ha (125
acres) site the total number would be in excess of 1000.
Under normal ground conditions it is estimated that for
small sites ground survey methods are cheaper than
photogrammetric methods; Whyte (1969) quotes 5 ha as
being the point at which aerial survey may start to be
cheaper than field survey work. Calculations of aerial
survey quotations made in the early years of this

project suggest that the breaking point is considerably
higher than 5 ha (12.5 acres). In the case of highly
contorted derelict land, however, the figure may be well
below this amount for a ground survey involving a great deal
of time to obtain the required number of levels. There

are however so many variables that these together with
changing costs for labour and machine operations make it
extremely difficult to make any firm general statement of
comparative costs which would have any meaning.

Aerial survey methods are now being adopted in this
country by the Ordnance Survey for the revision of some
features of its existing maps, the scale for the work

being 1:1250. This scale has been found convenient for
many reclamation sites particularly where the land is to
be returned to agricultural use. For small sites, and where
closer attention to detail is required, a scale of 1:500 may
be adopted and gives a more accurate delineation of the
site. The following table is based on information set down
by Whyte in a table on vertical photography for planning
and engineering works. It shows the relation of scale of
finished plan to photography commonly used, the
vertical and hoizontal accuracy and the minimum
possible contour interval which can be depicted.

Table 5.1 Levels of accuracy and detail for aerial
survey plan reproduction (after Whyte 1969)

Plan Photo Flying Accuracy Minimum
scale scale height plan Spot- possible
(above (m) height contour
ground) (m) interval
(m) (m)
1:500 1:3000 450 +015 +009 05
1:1000 1:4000 600 +020 +012 O05
1:1250 1:5000 750 +0:25 +015 0-75
1:2500 1:10000 1500 +051 +030 1:5

S———<<—{${$$—$_—$——————— ——————— 0

This represents the best conditions of reproduction; semi
dry copying will undoubtedly reduce the accuracy of
scaled distances. The theoretical minimum possible
contour interval is seldom reached except on even sites,
and in many cases it is often desirable when complex
topography results from deposition and subsequent
shale extraction to select contour intervals

sufficiently far apart to give a legible expression of the
topography. Thus, for clarity, it is frequently desirable
to select 5 ft intervals for contours at 1:500 scale rather
than | ft or even 2 ft intervals (Figs 5.1 and 5.2). S.I.
equivalents would be 2 m and % m for the two latter
closer intervals. Where subtle changes in levels, or very
accurate land forming is needed, for example adjoining
existing property, it may be necessary at this scale to
introduce 4 m contours, although this can only be
done for a limited area.

At 1:1250 scale a vertical interval of 2 ft (0.6 m) is
normally adopted. Here again the complexity of some
sites may lead to the adoption of a 5 ft (2 m) interval
(Fig.5.3).The same contours can be used at 1:2500
scale ( Fig.5.4).

The majority of sites with which the project has been
concerned were designed at 1:500 scale using 5 ft
contour intervals (the nearest S.I. equivalent being 2 m)
based on photogrammetric surveys. On some smaller sites,
notably Maria Colliery, 2 ft (0.6 m) contour intervals

ly \y

Fig. 5.1 1 ft contours at scale
1:500 are often difficult to
read when abrupt changes in
topography are to be
delineated, and less detailed
contour plans may give a
clearer overall picture.

Fig. 5.2 This shows a plan at
1:500 scale with 2 ft contours.
Even this degree of detail may
be too great for some
purposes and a 5 ft contour
distance accepted.

Fig 5.3 Plan scale 1:1250,
contour interval 2 ft produces
a mass of barely legible detail.

Fig. 5.4 Rough plan at
1:2500 scale with 5 ft
contours.

45

were used. At Roddymoor, where the site was to be
returned to agricultural pasture land, the scale chosen

was 121250. At Big Waters, survey information was
compiled from enlargements of the Ordnance Survey with
the contour information obtained by means of a field
survey conducted by the University Department of
Surveying.

5.2.2 Landscape survey

A limited form of landscape survey is of value in the
preparation of earthworks drawings, and at this stage use is
frequently made of the information collected for the final
design stage. In reality it is difficult to separate the parts
of the design process into watertight compartments, and

it is readily accepted that all the principles of the design
must be established before the details of one aspect, such as
earthmoving, can be investigated. In many cases the

design of a new landform is so much the major part of a
reclamation scheme as to comprise virtually the whole
design. The landscape survey must include the information
already mentioned on the topographical features of the
landscape surrounding the site, the drainage pattern of the
area, and the soils and geology of the district. It must also
include, for example, climatic factors such as shelter,
freedom from frost, and air drainage, and liability to
pollution from atmospheric sources. Techniques of land-
scape survey are set out in a number of standard works and
have been the subject of papers by Barnard (1965) Vyle
(1967) and discussion (Riddell and Downing 1967).

The landscape survey should also include an assessment of
existing vegetation on site, the positions of which will

have been noted in the topographic survey. This information
will provide a most useful guide to the status of material

in the heap and in its vicinity.

Derelict sites frequently call for particularly careful atten-
tion to discover the presence of unsuspected objects. Many
sites date from the era of the private coal operator, and
while the National Coal Board provides the most accurate
information it has available about pit shafts in particular,
and old buildings, foundations and other structures, it

is always advisable to proceed cautiously on site, since the
accuracy of old maps and surveys cannot be guaranteed. In
addition to knowledge of the exact location of shafts,
details of the method of capping or filling of the shaft

and the level at which this has been carried out, may be
vague and require some site investigation. Additionally,
close investigation of the structures and foundations on
site may reveal problems of demolition and removal

not readily detected during superficial inspection. Some
allowance must be made for this sort of unforeseen
contingency in costing projects. Such a contingency
occurred at Maria Colliery where an extra payment was
granted for the demolition of a foundation, the extent and
complexity of which were impossible to foresee.

At Haswell Colliery information regarding the presence of
shafts was obtained from the Estates Branch of the

National Coal Board, who were able to indicate the position
of shafts including balance weight staples, all of which

had been filled by the N.C.B. in 1952.

At Roddymoor, while some of the coke ovens on the site
were visible and had in fact been carefully dismantled,
another rank buried under the shale of the heap was only
discovered during operations.

These notes show that the landscape survey needs to be
extended to a careful investigation on site and by searches
with the appropriate authorities to establish the position
of any features which are not obviously visible and can
lead to additional work or danger.

46

5.2.3 Services and easements

On all sites in the project involving spoil movement it has
obviously been necessary to plot services, particularly

those which lie underground, as accurately as possible. Not
only is there a danger of disrupting services during excava-
tion with the dangers this presents, but there is also a

very real maintenance problem when the services are to

be buried more deeply than originally laid. The accuracy of
information from statutory undertakers needs always to be
regarded with some caution. Where any doubt exists the
authority should be asked to mark the line of the service
on site. Statutory undertakers usually stipulate very
precise depths of cover to be maintained over services

and this can act as a limiting factor in regrading since
re-routing major services is prohibitively expensive. The
profile of an extensive area of the site at Copperas Lane has
been closely controlled by the line and elevation of a

30 in water supply main crossing the site.

5.2.4 General information

Other information has to be gathered to build up a
complete picture of the site and its surroundings, both at
the time of the survey and later during development. The
local planning authority’s preference for the development
of an area is usually expressed in local development plans
in which appropriate forms of development for the site to
be reclaimed are indicated if not specifically, then by
general development proposals for the area. Experience on
the project has shown that it is unwise to embark on
design projects on land which has not already been
acquired by the local authority. It is, of course, possible for
a local authority to undertake work on land it does not
own and which is to remain in private hands, but this is
eligible for grant only under very special circumstances.
Difficulties of acquiring land for reclamation work have
been experienced on two project sites: Percy Pit and
Haswell Colliery. On the first site difficulties arising from a
leasehold agreement led to a stalemate over agreement for
compensation, whilst on the second, local authority
compulsory purchase was opposed by the lessees, who were
shale extractors. The Ministry agreed that the Local
Authority’s intention to reclaim the land was not
sufficiently urgent to override the need to extract the
mineral.

When ownership is established, the presence of any

public footpaths, rights of way or easements, whether
public or private, needs to be ascertained. The presence of
squatters on derelict land is quite common, and it is
possible that by virtue of length of establishment on a

site some rights will have been acquired by the squatter.
Agricultural tenancies may also present problems in
relation to the progress of reclamation of the land. It is as
well that the presence of tenants and squatters is clearly
established at an early stage, so that the appropriate

action may be taken. At St. Anthony’s (Northbourne Park)
there was a tenant with an unexpired lease who had to be
given adequate notice to quit. The contractor co-operated
by working around the area of the tenancy, completing the
works when the tenant was finally evicted. This is not,
however, a happy situation and relies heavily on the
goodwill of the contractor.

Where parts of sites adjoin public highways, it is clearly
desirable to obtain information from the local highway
authority so as to take account of any proposals for
present or future road widening, highway control lines and

where appropriate, lines of sight. With the development of
the design proposals, the information may be extended

to cover enquiries as to suitable sites for depositing
material from the site to be reclaimed, or sources of
covering material. At Maria Colliery the design problem
was solved by removing the heaps into an adjoining clay
pit. At Felling, it initially appeared that a satisfactory design
could not be achieved without exporting considerable
quantities of the shale. It was necessary to investigate

the possible sites for deposition, and their distance from
the reclamation site together with methods of transport-
ation and the costs. Methods such as rail, road and even
hydraulic pipeline were investigated in relation to the need
for fill for a riverside area about eight miles from the site
at Jarrow Slake. The proposed alternatives were all
prohibitively expensive and this investigation was
discontinued. Subsequently investigations into the
importation of material to act as a top dressing for the
very acid shale were put in hand. This involved clay and
topsoil from existing road and building works near to

the site where the material could be obtained and
transported reasonably economically.

The economic use of material from derelict sites should
not be entirely ignored. In most cases, sites with
recognised or suspected economic value are not made
available by the owners or lessees without protest and
one can generally assume that a site released by the
National Coal Board has no economic worth.
Nevertheless the possibility that some economic

return may be obtained to offset the high costs of
reclamation should always be borne in mind, particularly
in a world in which demand and economic circumstances
can change so rapidly.

5.3 Geochemical investigations

The variation in shale materials, both physical and
chemical, is dealt with in detail in Chapter 8 of this volume.
It is sufficient to mention here that standard procedures
have now been evolved whereby the chemical and physical
properties of the shale can be assessed for its potential to
support plant growth and form soil. This is important
since the quality of shale in different sectors of a site may
affect the regrading proposals. Some materials may need to
be deeply buried because they are toxic or have a high

coal content; others because they are composed of lum ps
of fused material which cannot be broken down either
mechanically or by erosion. Some red shales, on the other
hand, appear to have excellent soil forming and plant
supporting qualities, and can be used as a top dressing

over other less suitable materials.

It has become common practice to employ specialists

to undertake a specific series of tests on the materials on
site to establish its likely future behaviour and potential
and this practice has been followed on the research
project. This is not so much from the point of view of
its soil forming potential, which is established by a series
of soil science tests discussed in Chapter 8 and carried
out by a soil scientist, but to establish its stability,
combustibility, sulphur content, and the presence of
gases. This is usually undertaken by the setting out of a
grid to give surface samples which can provide a
representative picture of the material covering the site.
Deep bore hole samples are also taken at varying depths at
selected points on the site. These are chosen where the

Table 5.2 Check list of survey information used for
design of earthworks for reclaimed landscape,
particularly oriented to colliery spoil areas.

Information Source

Aerial survey,

OS plan or ground survey
plus ground spot level
survey.

1. Contours

either

2. Landscape survey

a) Existing vegetation species Site observations
age and condition.

b) Shale types (visual
classification)

c) Vegetational cover
of shales.

d) Natural soil types
(Where present)

N.A.A.S. or simple
classification.

e) Geology Geological survey.
f) Surface water drainage Site observation (see also 4)
pattern

g) Aspect, shelter
exposure, etc.

h) Visual aspects, views,
areas of containment,
ridges, dominant
features

i) Structures and
foundations on site

” ”

3. Features on site not readily visible

a) Pit shafts National Coal Board
Area Chief Surveyor

b) Counter balance weight ai i

staples

c) Coke ovens

d) Structures

e) Foundations

4. Services
a) Electricity Underground (C.E.G.B. &
" Overhead Area Board
b) Gas Underground Area Board
c) Water Underground Local Water Authority

d) Telephone Underground Post Office
Overhead
e) T.V./Radio Underground’ Rediffusion
f) Main sewers Local Authority
g) Other underground Local Planning Authority
pipelines (oil etc.)
h) Surface water
culverts

National Coal Board, Area
Chief Surveyor.
Local Authority (see also 2)

5. Landownership etc.
a) Land ownership Local Authority
Ministry of Agriculture

Land Registry

b) Tenancies Landowner
c) Public Rights of Way Local Planning Authority
d) Easements Landowner

e) Highway control lines
of adjoining roads

Local Highway Authority

6. General Information
County or District
planning proposals
for area of sites

7. Geochemical Site

Local Planning Authority

Specialist consultants

Investigation
8. ‘Soil’ condition Soil Science Department of
Investigations University.

——

47

material is thickest or where some particular problem
may be encountered. For surface samples, a site of some
16 ha (40 acres) might be adequately covered by 100
samples, as was the case at Felling area 3. This, it will

be appreciated, is a figure which can be greatly varied

to suit different sites. Generally, it is possible to detect
superficially the major changes in the composition of
material, and the grid will be constructed so that each
change is adequately represented in the samples.Deep
boring is an expensive operation and so the num ber of
sam ples that can be taken in this way is very limited.
This introduces a large element of chance into the

sam pling due to the heterogeneous nature of the contents
of most shale heaps. Unless large sums of money are to
be expended initially this has to be accepted, and if
problems are revealed it may be necessary to undertake
further boring to get a clearer picture of the inside of
the heap.

5.3.1 Heat

One of the first questions for investigation in the survey

of a pit heap is the temperature within the heap. The
presence of hot material in a pit heap will clearly direct
the method of working to avoid aggravating the condition,
and mean that additional work may be involved to cut

out the heating area and render the heap relatively harmless
after regrading, which would not be the case were any

hot pockets allowed to remain. The presence of severe
heating can be detected by the use of a surface probing
thermometer with a probe approximately | m in length
which can be plunged into the surface of the material.
This may, however, only indicate surface heating, as was
experienced in a series of small heaps at Big Waters. In

this case, the surface of the heap reached high
temperatures, and smoke and flames were frequently to be
seen, whereas the centre of the heap was known to be
almost completely unaffected by heating. Use can be made
of the boreholes drilled to provide core samples to give

temperature readings of the interior of the heap at different
levels. This is done using a thermocouple lowered into the
borehole which is then plugged. Some time is allowed to
elapse for the temperature reading to become steady, as

it is liable to be affected by the drilling operation and

the passage of air into the heap, and the temperature is
read at 15 minute intervals until stable. From the readings
taken it is sometimes possible to build up a reasonably
com prehensive picture of the temperature regime inside a
heap. The presence of serious heating problems may call
for prolonged investigation and the retention of thermo-
couples in the heap to detect trends, such as serious rises
in temperature or spread of the areas of heating. Methods
of dealing with hot areas are discussed in Chapter 6.

5.3.2 Gas analysis

It has been found desirable to carry out additional tests in
some circumstances, particularly where heating is occurring,
to determine the presence of toxic gases such as carbon
monoxide and dioxide, sulphur dioxide, and hydrogen
sulphide, all of which could be dangerous to operatives
working on the heap. It is likely that gas analysis will need
to be carried out on all sites; early investigations of pit heaps
have established which gases are likely to be encountered,
and it may only be necessary to undertake tests where a
specific hazard is anticipated. Even then the gases likely to
be responsible for these dangers are, with the exception of

48

carbon monoxide, to be easily detected. Carbon monoxide
can be guarded against by the wearing of sensitive discs
by operatives where its presence is suspected.

5.3.3 Materials

The physical nature of materials found on site has been
determined by the standard procedures of the grading
analysis (by sieving), the index classification test, and the
sedimentation analysis using the pipette sampling method
(BS 1377 test 12), all of Which are described in standard
textbooks of Engineering Soil Mechanics (BS 1377:1967).
These provide information on the strength and stability of
spoil materials which may not be immediately relevant
except where construction is proposed on site or where the
material is to be shaped into steep banks or considered for
load bearing bases. They may also provide valuable

records for future reference, particularly where a change to
some more intensive use is proposed. It is also desirable to
test samples for moisture content.

5.3.4 Combustibles

Tests have also been applied to samples to establish the
presence of combustible materials, either by determination
of free coal as on earlier sites, or by total combustibles
from loss of weight on ignition at 800°C.

5.3.5 Sulphates

Simple tests have been used to determine the free sulphur
content and the sulphur trioxide content of shale soils.
The value of these tests is questionable in the light of the
very complex chemical regime of coal shales. At present
work in a number of centres on the status of pyrites is
aimed at arriving at more conclusive understanding of

the availability of sulphur in various forms under differing
conditions of spoil. The simple tests may, however, be
adequate for the assessment of the effect of the materials
on concrete and bricks used in drainage and building
construction. Further discussion of this topic is found in
Chapter 8.

5.3.6 pH

Experiments on the project and on other shale sites have
shown that it is necessary for pH tests to be undertaken,
using pH meters with glass electrodes, to obtain accurate
readings of the low pH commonly discovered on shales. The
use of the British Standard method of pH test involving

a colorimetric technique which does not give a reading
below pH 4 is of no value except at the initial field

testing stage, and should be specifically excluded from the
required works.

5.4 Earthwork computations

Clark (1953) classifies the methods of calculation of
volumes according to whether the solid to be measured is
defined by (a) cross sections, (b) spot levels or (c) contour
lines. Writing before the development of computers, he
favoured the cross section method and suggested that using
spot levels is useful occasionally where large excavations
are concerned, but that the method of contours is suitable
only for rough calculation. This argument will be well
known to engineers and surveyors.

Roberts and Stothard (1968) have shown how recent work
with computers at the Road Research Laboratory, and

studies of alternative road design calculation methods, have
suggested that a grid of levels may be the most appropriate
method for calculating earth movement for highway
design. It is well within the required scale of accuracy for
this work, and has the advantage that regular grids may be
transferred direct from the original aerial survey to the
computer data bank (Craig and Burns 1967). The
application of this type of system to reclamation
calculations is at present under study. The degree of accuracy
which is obtainable from a grid of levels on exceptionally
broken ground, such as is frequently met on reclamation
sites, may not favour the use of this approach on such sites,
a point already made in relation to field surveys of sites.
Different sites within the project have made use of
different methods of earthworks calculation depending on
the size and topography.

5.4.1 Grid method

The use of the grid method, despite the limitations in
relation to existing ground which have already been
expressed, has been adopted at several project sites
particularly for preliminary design calculations, with the
final calculations being undertaken by another method.
Where the existing topography was sufficiently even to
enable the method to provide the final design quantities,
as at the Big Waters site, a grid interval of 100 ft (30 m)
was adopted. The calculation of the major earthworks was,
in this case, achieved with a grid of 108 spot levels. This
scale of grid is adopted by the National Coal Board for

its opencast works and it may well be that while potential
error is satisfactory in relation to the very large volumes of
material moved in open cast operations, a greater degree of
accuracy is required where the depth of material moved is
small and the potential margin of error is large in
proportion to the volume of excavation and deposition. The
steepness of the sides of the heap and the changes of
gradient of the material at Roddymoor meant that, even
with careful centring of the grid, the use of the 100 ft

(30 m) interval resulted in considerable errors.

At Maria Colliery and Haswell Colliery, a 30 ft (9 m) grid
was adopted. In the first of these sites this appears, from
the finished levels and comparison of the contractor’s spoil
movement records with the calculated quantities, to have
oie a reasonable degree of accuracy. Haswell Colliery,
owever, was a case where shale extraction operations
had taken place, and the ground surface was exceedingly
uneven with the result that the volumetric result obtained
has to be considered with some caution. Despite the problem
of accuracy, this method is a very useful design system
enabling the designer to obtain a quick approximation of the
volumetric consequences of new grading proposals. Even
if this has subsequently to be checked by other methods
and final amendments made, it is still worth doing to
reduce calculation complexity in the formulation of the
design. At Maria Colliery, the quantity surveyor undertook
an independent check by means of cross sections of the
volumetric calculations obtained by the grid method and
reached a close enough agreement for the volumes to be
accepted for contract purposes. At Percy Pit, where the
pattern and areas of movement of material were very clear
and simple, with a conical pit heap to be reduced and
large specific areas of cut and fill, a grid of 30 ft (9 m
approx.) was adopted as being reasonably representative of
the changes in topography on site. This meant reading over
900 spot heights, and possibly a larger grid could have

been used without significant loss of accuracy. The simple
shape of the heap on site enabled the use of the contour
method for balancing the cut and fill, as it was possible to
balance the fill quantities required against a cut of
varying thickness of the cone until a reasonable balance
was achieved.

5.4.2 Computer application of the grid method

Indications have already been given in this chapter of the
application of computers to the calculation of earth work
volumes in the design of highways in which a grid of levels
is the basis of the method. The accuracy obtainable with a
rigid grid, which may not reflect detailed changes in level,
is a limiting factor to its use on reclamation sites, which as
already indicated, may have very broken topography. Set
against this is the fact that the square grid has great
advantages in ease of recording, storing and recalling data.
Craig and Burns (1967) indicate that the accuracy of this
type of grid is a function of the spacing adopted, and
recommend a method involving variable spacing according
to the topographical requirements. Work on grid
accuracies is still in progress at the Road Research
Laboratory, but from Craig and Burns’ work, Roberts and
Stothard were able to suggest relationships between grid
point spacing and contour and ground shape which give an
acceptable accuracy. This may be used as a guide in both
computer and manual operations of the grid method of
volume calculations.

Table 5.3 Grid point spacing related to ground & contour
shape (after Roberts & Stothard).

General ground shape (average slopes)

Contour shape 1:100 1:50 1:25 1:10
Regular 150 100 75 50
(50) (35) (25) (20)
Uneven 100 75 50 25
(35) (25) (20) (10)
Very irregular 75 50 25 25
(25) (20) (10) (10)

Table originally published in feet, S.1. equivalents (m) in
brackets.

The fact that the requirement for accuracy of finished
levels on reclamation sites is so much less critical than

on highways may make the system acceptable, in spite

of the inherent inaccuracies, because of the ease of use. A
series of exercises to compare the acceptable levels of
accuracy with those actually achieved with different
methods of computation would provide a valuable insight
into the methods available, and might even suggest those
most suitable for general application.

Craig and Burns (1967) indicated the value of investigating
a columnar method of calculating earth volumes in
highway work and particularly at traffic interchanges. An
interesting adaptation of this use of a regular grid on a
reclamation site was that used by Messrs. Costain Mining
Ltd., for the Acorn Bank open cast site at Bedlington,
Northumberland. Here the land was to be restored to
agriculture after the extraction of the coal. Rigorous
requirements in relation to the level of the adjoining land,
angles of slope, and drainage were in force, and the firm’s

49

operational research department were able to make use of
computer operations to provide a series of solutions giving
finished levels in which the relationship of adjoining and
adjacent grid points satisfied a mathematical relationship.
Concurrently it was possible to select the solution giving

the minimum oversite transportation of material. The
computer programmes used have not been published but

the method was described in a paper given at the Operational
Research Society's annual conference, Sept. 1966 (Caruthers
and Canvin 1966). It should be noted, however, that such
areas are usually less complex topographically than are
colliery spoil areas, and therefore do not involve the
calculator with a multiplicity of measurement.

5.4.3 Contour method

It is widely accepted that this method is suitable only on
certain sites where the existing topography is reasonably
simple and clearly defined. The system, depending on
measurement with a planimeter and defining areas of cut
and fill, will be familiar to all surveyors. The ease of design
manipulation afforded by this method commends it on
those sites where the topography permits easy identification
of cut and fill sectors and measurements of areas. Its
limited application needs little emphasis and it has not

been suitable for computer use.

5.4.4 Cross section method

This method is as well known as the others previously
mentioned and requires no description.

A good example of the way in which this method is used
is provided by notes prepared by the planning department
of Lancashire County Council. Two systems are in use,
the second being strongly based on a physically defined
centre line or base line from which measurements can be
taken at all times on site. The following notes prepared by
Lancashire County Planning Department describe the
method very clearly. Original measurements in fact are
retained throughout.

Reclamation work

Notes on the preparation of contract documents with
particular reference to the balancing of cut and fill

Methods adopted in preparation of Bryn Road and
Careless Lane schemes

1. Survey of site-contours at one foot vertical interval
plotted to 1/500 scale.

io]

. Sections at 50 ft intervals - directly from contours on a
print of site surveys to indicate existing ground levels.
These sections are drawn to scale one inch to 10 ft
vertically and 1/500 horizontally.

3. After giving consideration to existing ground levels
immediately outside the site boundary and the invert
levels of any culverts, drains or watercourses which may
exist, tentative new ground levels are fixed and proposed
contours are also drawn on the print of the site survey
referred to in item 1.

4. Sections through the proposed ground level are
projected directly from the print of the site survey
(referred to in items 2 and 3)\which now indicates
existing and proposed ground levels on to the section
referred to in item 2.

50

5. Quantities of cut and fill are obtained from the sections,
referred to in item 4, by means of planimeter. A
suitable allowance is made for bulking or compaction
dependent upon the type of material and a trial
balance is made.

6. Ifa balance is not achieved within an acceptable limit
(being the equivalent of 1% in over the area of the site,
or 200 yd? per acre) then some adjustment of the
proposed level of the whole area is effected by drawing a
new contour line on the print of the site survey at such
a fraction of the distance that will raise or lower the

level of the surface as is necessary in multiples of 1 Y, in,
i.e. 11), in equals I, of a foot, therefore a new contour is
easily positioned within /;, 1/,, 7/;, or !/, the distance
between any two of the tentative ground level contours.

7. The sections in item 2 are now redrawn and fresh
quantities of C (cut) and F (fill) computed. If at this
stage an unacceptable difference exists, then a minor
adjustment of levels over a small area of the site may
give a balance.

Present method now undergoing trial
Stoney Land site (1968)

1. The boundary of the site and any features thereon are
surveyed and plotted to 1/500 scale.

2. A base line is set out across the site by instrument in
such a position that all or most of it is accessible. The
position of the line is fixed at boundaries and other
convenient positions by 4 in dia. steel bars set in
concrete. The line provides the base from which
subsequent levelling operations, setting out, and
checking of actual contract operations may be
controlled. The position of the base line is then recorded
on the outline survey, item 1.

3. At intervals of SO ft along the base line, instrument
stations are established and by means of theodolite lines
at right angles to’ the base line, i.e. section lines, are
established and ground levels are taken thereon at
all changes of level or gradient. The levels are reduced and
their values are plotted directly along section lines which
are drawn in their true position on the outline survey.

4. A print of the information now recorded is obtained
and rough contours of the existing ground at S ft
intervals are now pencilled in to show the humps or
hollows. This is intended as a guide only to the ground
configuration, and may be dispensed with if a careful
visual inspection of the site is made from all possible
vantage points. After giving consideration to the
factors referred to in item 3 under heading Bryn Road/
Careless Lane tentative new ground levels are drawn.

5. Sections are drawn by direct projection from the print
referred to in item 4 which now contains both existing
and proposed ground levels. Cut and fill quantities are
obtained from these sections and the trial balance
effected with any necessary allowances for compaction.

6. If a balance is not achieved see methods of obtaining an
acceptable limit in item 6.

The operation of these methods obviously depends on the
ease of surveying and availability of staff to do the
subsequent drawings and calculations. Under circumstances

where staff are available, and where surveying on site is an
appropriate method of gaining survey information, it
appears from the Lancashire experience that the method
gives satisfactory results economically and it therefore
deserves consideration when the method of operations is
to be chosen.

Cross sections have been used in this project as a check
method on a number of sites, with measurements based
on scaled drawings and planimeter reading. This method
is obviously subject to errors resulting from the
difficulties of drawing sections accurately but has proved
adequate for a number of small contracts, notably
Egerton Gardens, where it was the only method used, and
Maria Colliery.

5.4.5 Computer applications of cross section
method

The selection of a particular method when using the
com puter to carry out the calculations will depend upon the
aspects previously discussed. It will also depend on the
availability of a suitable computer programme, assuming
that there is not the volume of work to justify the
composition of a new programme. At the time that the
volumetric calculations were beginning on sites of this
project, inquiries were made as to the practicability of

/ Various methods and it was concluded that for ease,
convenience and economic reasons the use of the road
programme devised by Sir Robert MacAlpine & Sons Ltd
was the most suitable available method. In this case the
work required of the computer is not the solution of the
design, which is undertaken in some computer operations,
but the comparatively simple, arithmetical calculation
of the volume of cut and fill and their relative balance
over the site. Even for such an apparently simple task the
computer has advantages. Human calculators would be
involved in tedious arithmetic, and the expenditure of
skilled man power in this way should be avoided whenever
possible. As indicated, calculations are based on end areas
obtained by the delineation of cross sections at
selected intervals along a centre line which represents
the centre line of road. When this system, embodied in the
com puter programme chosen is used on a reclamation
site, the limitations of the programme may make it
necessary to divide the site into two or more parts each
with its own centre line. This is because the computer,
designed to measure a linear feature is only programmed
to accept 18 measurement points or ground points at a
maximum offset of 999.99 linear units on each section for
either existing ground level or for the regraded surface. It
is in selecting the placement of the centre line, and
establishing the best and most representative position for
the cross sections that time and skill are required; this is
true irrespective of the use of a computer or human
agents. Indeed, where some degree of simplification of
calculations is desired the section lines are commonly set
at equal intervals, making the selection of representative
positions more difficult. Where end areas are to be
measured without com puter aid, it is desirable that
existing and proposed ground points should coincide.

Alternatively the method of drawing sections and
measuring the area by planimeter is adopted. Both of
these methods involve time, and both are liable toa
degree of inaccuracy. In the first case this is due to the use
of simplified formulae and compromise in the selection of

ground points when the error is endemic and in the
second case to the liability to error in the reproduction of
section drawings in which case care can minimise error. The
computer method suffers from neither of these specific
limitations. No formula within the capacity of the
programme is too time consuming. The accuracy of the
result still, however, depends on the selection of the most
representative sections and points and on the survey itself.
Were the method not dependent on the errors of
reproduction of the survey drawing, a greater degree of
accuracy could be obtained: thus a data sheet prepared
using original ground survey readings made on site or a
direct reading of aerial survey material would show the
highest possible degree of accuracy of calculation. A
number of computer systems now are dependent on
photogrammetry making use of a stereo plotter working
direct on the original survey photographs. The co-
ordinates produced by the stereo plotter are recorded and
stored in the computer in the form of a digital ground
model and any complexity of ground form can be
calculated. By the introduction of these techniques some
people believe that the need for contour plans is
completely eliminated in highway work, and this might
well be the case for existing contour plans in reclamation
projects; however, the cost and availability of computer
time and the possibility of the need for re-runs must not be
discounted.

Present experiments within the project, however, have
been limited to the measurement of ground points from
the aerial survey plans prepared from the original flight
material. Once the centre line has been selected, sections
at random intervals to give the best and most accurate
approximation of topographical changes are taken.
Section points are then selected to reflect most
accurately, within the limitations of the numbers of
points available, the changes in topography. It is then
necessary to translate this information from the plan to the
data sheet, recording the height of the point and the offset
distance from the centre line. This work can be done
relatively speedily, and it has been estimated that one
section, comprising 36 height and 36 offset measurements
can be completed in 20 minutes. Ground point data is
recorded on one sheet, and regraded level points data (in
the road programme referred to as ‘Road Formation
Points Data’) on another, as will be seen from the
examples (Figs 5.5, 5.6).

It will also be seen that while the section lines are the
same for each series the section points bear no relationship
to each other but are recorded quite independently.

When the information is fed into the computer the
print-out information includes:

(a) The co-ordinates of the points of intersection of the
side slopes with the original ground at each specified
cross-section.

(b)The cut and/or fill areas at each cross-section.

(c) The cut and/or fill volumes between adjacent cross-

sections, using the “end area” method. It also
accumulates those volumes to the end of the roadway.

(d)The topsoil volume between adjacent cross-sections,
keeping topsoil in cut areas separate from topsoil in
fill areas. It also accumulates these volumes to the
end of the roadway.

51

Se ALE 8 RE LD ANE AIOKRIED COMPARE

COMPUTER ROADWORKS SYSTEM

SHEETING csvset

GROUND POINTS DATA
CONTRACT

OFFSET LEVEL OFFSET

3\ 3 ——_ ©

nM

1d La

LEVEL

OFFSET |

LEVEL

OFFSET LEVEL OFFSET LEVEL | OFFSET LEVEL =}
l
SS) 56 0} 6) —— 6s] 7o]/71 %

{
r
|
|
]
|

“—

Fig. 5.5 (By courtesy of Sir Robert McAlpine and Sons Ltd.)

Det ALPINE & SON LTD AND ASSOCIATED COMPANIES

COMPUTER ROADWORKS SYSTEM

SHEET No\cists/erreeeree

ROAD FORMATION POINTS DATA

contract. Harceeh( Gu

OFFSET LEVEL

T

OFFSET

,0,0°0 Olf, ¢S°0 olf, 3 3° 0, 1%, ¢S° oa, 12,

.8,8°2,24,3,9" 2, Bele ege eos pec eat

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c lth S+0.01
ia
14-1 (|

©.0/230°0O% S O° 00|2,07° xe)

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MEF: CAS (F)

Fig. 5.6 (By courtesy of Sir Robert McAlpine and Sons Ltd.)

52

(e) The area of side slopes on both sides of the roadway
between adjacent cross-sections, and accumulates
these areas to the end of the roadway (McMillan 1965).

The information is printed out in two reports, only one of
which is relevant to the regrading of reclaimed land. This
contains the information indicated under items |, 2 and 3
(Fig.5.7). The separate recording of cut and fill between
sections, as well as the accumulated total, makes it
possible, when a balance has been achieved, to apportion
the excess material in one section to appropriate adjacent
sections and present this material in a table in the bill of
quantities for the guidance of tenderers (Fig.S.8). This is
related to a plan on which lettered sections are shown.

In the case of Haswell Colliery site, for which the first
exercise was carried out, the total was twenty-seven
sections on the plan. The balance was not achieved on the
first attempt, and a redesign which achieved a balance
involved revising and rerunning seventeen of these
sections, the total cost of the calculation being £44. This
method has been used on the Windynook/Whitehills site
at Felling where the ratio of surface area to spoil resulted
in critical slope angles and volumes and created the need
for a high degree of accuracy, while at Maria Colliery

sim ple cross-sections with end area calculations have
provided a sufficient degree of accuracy.

A more sophisticated computer programme offering SO
ground points is under trial with Northumberland County
Council. This will undoubtedly allow of a more flexible
approach and result in greater accuracy in assessment of the
volumes. Additionally it is intended ultimately to provide
alternative design solutions as well as calculating volumes
of material moved.

5.4.6 Comparison of calculation methods

The use of a particular method of calculation clearly must
depend on the type of site, and the availability of staff.

On small sites with simple topography, a grid of levels will
give an adequate result; alternatively a series of cross-
sections may be taken and the volumes measured with a
planimeter. In some circumstances, notably when the areas
of cut and of fill are large and easily defined, not necessarily
simply shaped but with bold gradient changes, the use of
contour methods for the measurements may be adopted. As
already indicated this could well be suitable in a case like
Percy Pit where a conical heap was to be reduced and the
surrounding area raised, and cut and fill are clearly defined.
More complex and larger sites require the use of sections
and the end area formula. The question is then whether
this is to be undertaken by computer method or by hand.
The investigations carried out originally for the project
suggested that the expense of writing a special programme
for a limited amount of work was not justified, but where

a suitable programme was available its use could result in
time saving in a busy office as well as the possibility of
some economic advantage. It is difficult on the information
available to make any straight comparison of the economics
of the manual and the computer approach, but work

which would involve measurement and calculation manually
for periods of five to six weeks can be completed in the
same number of days when the computer is employed.
Making use of an existing programme the cost is £1 per
section to obtain the information previously listed. In the
case of amendments to the contours to obtain a cut and

fill balance it is possible to rerun as few or as many sections
as desired, and so no excessive costs are entailed. The
computer cross-section method then appears to be certainly
as cheap as hand methods, undoubtedly more accurate, and
to allow of simple checking in the event of any query.
Other methods are in process of investigation and
refinement, but at present this system is probably the best
approach available, without the expense of writing a
programme for special use. It is hoped that the current
Highway Construction approach using digital ground
models direct from the original aerial survey, and

Station Cut Vol Fill Vol Acc.Cut Acc. Fill CutArea_ Fill Area Intersection Points
Left Right
(yd3) (yd3) (yd3) (yd3) (ft2) (ft?) x Y x
x x x x
0. 312. 7366. 312. 7366. 89.12 535.39 121.00 425.00 183.38 422.62
75 2236. 13618. 2548. 20984. 135.58 4768.10 224.17 432.17 389.13 418.13
150. 4783 12230. 7331. 33214. 474.59 5037.13 288.22 430.22 388.11 419.11
225 8891 12844. 16223. 46058. 1969.26 3768.52 290.63 434.37 388.21 423.79
300. 23882 13538. 40104. 59596. 4432.41 5479.44 291.22 444.22 387.14 425.86
375. 24788 14553. 64893. 74149. 12762.31 4267.81 304.46 449.46 387.08 425.95
450. 13649 16496. 78542. 90645. 5085.36 6210.45 309.30 441.30 386.05 433.97
525. 12904 16667. 91446. 107312. 4741.99 5666.45 362.95 440.93 385.04 437.04
600. 14147 19674. 105593. 126986. 4548.94 6333.96 380.28 447.28 385.11 448.11
700. 10528. 11413. 116121. 138399. 3090.62 4290.11 559.02 444.98 384.07 451.07
800. 11268. 6108. 127389. 144507. 2594.47 1872.79 467.02 449.98 383.06 454.94
900. 12926. 20021. 140315. 164538. 3490.06 1425.64 457.07 454.07 383.12 441.12
1100. 3578 21193. 143893. 185721. 0.00 3980.04 431.00 460.00 381.02 444.98
1300. 3901. 5179. 147794. 190900. 966.05 1742.05 375.00 450.00 383.04 436.04
1400. 6741. 2670. 154534. 193570. 1140.28 1054.48 321.03 467.97 352.03 435.03
1500. 4629. 4689. 159163. 198269. 2499.62 387.14 225.00 460.00 326.52 434.48
1600. 3 © 4808. 159184. 203067. 0.00 2145.05 166.18 455.84 295.47 432.53
1700. 182. 4903. 159366. 207970. 11.09 451.30 92.06 454.94 257.33 435.33
2000. 72,17 77946 21.72 431.32 41.00 454.00 91.06 446.06
231474 285916

Fig. 5.7 The cut and fill volumes for individual cross sections and the accumulated totals are the significant figures for

earthworks.

53

eee ny [a |
CUT and FILL TABLE
all quantities shown are in cubic yards

TOTAL apportionment apportionment TOTAL
CUT FILE

Sections BB/Embankment
NIL

from BB/CC 535
from CC/DD

Sections BB/CC
535- 535 to BB/Emb.

from CC/DD
from DD/EE

Sections CC/DD

4,305- 3,258 to BB/Emb.
1,047 to BB/CC

from DD/EE
from EE/FF

Sections DD/EE

12,328 - 11,344 to BB/CC
984 to CC/DD

Sections EE/FF

39,363- 6,429 to CC/DD
7,956 to DD/EE

12,513 to EE/FF

8,615 to FF/GG

3,850 to GG/HH

Sections FF/GG

74,227- 2,673 to GG/HH
4,867 to HH/JJ
3,445 to JJ/KK
2,428 to KK/LL
8,186 to LL/MM
11,364 to MM/NN
18,921 to NN/OO
20,214 to OO/PP
2,129 to PP/QQ

Sections GG/HH

22,445 - 13,666 to PP/QQ
8,779 to QQ/RR

from EE/FF

from EE/FF

from EE/FF

from EE/FF
from FF/GG

Sections HH/JJ
3,158- 3,158 to QO/RR

Sections JJ/KK

10,816 - 10,816 to QO/RR

Sections KK/LL

22,533- 2,383 to QQ/RR
20,150 to RR/SS

from FF/GG

from FF/GG

from FF/GG

Fig. 5.8 Table showing the movement of volumes from section to section.

54

subsequently to draw a new contour plan or a series of plans
based on requirements of topography and aspect by
computer, will ultimately be adapted to land reclamation.
The perfecting of such a programme may well need to be
undertaken as an academic study because the costs of this
sort of research may be beyond the means of designers or
may not seem to be economically advantageous, but it
should be available for use by all where it is considered an
advantage.

Additionally, comparative tests could be made on a site or
sites where earthworking has been undertaken, where the
values for compaction or bulking can be accurately
assessed. Photographs from before and after reclamation
are available for a number of sites; the actual volume
changes can be determined accurately by the use of
digital ground models and against this various methods of
calculations of volume could be tested. These should be
preferably assessed not only for accuracy but also for the
time taken and level of skill needed to operate them.

The assessments could also be compared with any
contractor’s records of material movement.

5.5 Machinery for regrading

5.5.1 Scrapers and the other machines

It is accepted that the ideal machine for the regrading of
pit heap material is the wheeled scraper which comes in a
variety of shapes and sizes and may carry from 10 to 45
yd3 (7-5 - 33 m3) of material. On small sites, or sites
where space is restricted, smaller scrapers towed by
crawler tractors may be substituted, and this may be the
case where other difficulties such as high temperatures and
wet conditions prevail. The advantage of the scraper is that
it can handle the complete cycle of material movement by
itself, and when the cost of machines has to be borne in
mind, smooth operation and quick handling are a major
consideration. The use of face shovels or draglines may

be necessary in certain circumstances where particular
difficulties prevail, but this immediately involves
additional machinery to transport the material and regrade
it at its destination, and adds considerably to both the
complexity of the operation and its cost. The use of this
type of equipment is thus clearly limited to those occasions
where there is a long haul off the site, or possibly for
handling slurry materials or burning shale. Experience at
Roddymoor in the handling of hot shale with temperatures
of up to 450°C showed that burning pockets could be
opened up with a bulldozer blade and the material spread
over the adjoining surface where it quickly cooled to a
temperature at which it could be handled by the

scrapers. Exceptionally large hot pockets might require
some special treatment devised to suit the circumstances
but the degree of combustion to be encountered would be
ascertained by the specialised survey undertaken before
the commencement of works.

When scrapers are employed it has been found advisable
to follow normal civil and highway engineering practice
and ensure that the grade is kept even and smooth by
running over the operational area with a blade grader.

At Maria Colliery, the contractor operated with a front
bucket loader with % yd? capacity which he used with four
lorries of approximately 6 yd3 capacity. A small site,

Maria Colliery involved earthm ovement of 80,000 yd3
over a round trip of about a quarter mile,and this proved

to be an economic proposition. The use of scrapers would
have involved the construction of a special haul road which
crossed a brook at one point. With a length of haul in
excess of approximately 100 yd, scrapers towed by tracked
vehicles are inappropriate except for special conditions
such as handling hot material, slurry or possibly for
breaking up fused material. The use of the bucket loader
and four lorries at Maria involved a throughput of up to
1500 yd3a day. The ease of operation in this case has
depended on the original method of deposition. Excavation
from the base of the heap starting with the newest

material working back to the oldest meant that the
material fell easily towards the loader. One complication
introduced by using the tipping method at the point of
deposition is that compaction is much less and the

volume of fill is much greater. In the case of Maria this
was, fortunately, not critical.

In terms of cost, one significant advantage usually
encountered in colliery waste sites is the open condition
and easy drainage of the material. This has meant that
operations can be undertaken in conditions when the
normal clay soils which predominate in the British Isles
would make plant operations totally impossible. A great
deal of shale regrading work provides employment at a
time of year when machinery would otherwise be standing
idle, and this is advantageous to both client and contractor.
Contract timing should be considered with this factor very
much in mind.

5.5.2 Compaction and bulking

Calculations of material regrading to be done by scrapers
must make allowances for loss of volume resulting from
compaction on respreading. This rather variable factor,
which depends on the types of machine in use, the nature
of the material, and the way in which it was deposited,
has generally been assumed to be about 12%%. In

County Durham it has been found that with the smaller
and lower heaps, compaction may be up to 25%, while in
larger heaps the figure will be between 10 and 15%.

Where other methods of deposition are adopted, for
example a dragline with only the surface graded by
bulldozer, the compaction factor will be quite different, and
indeed in certain conditions the regraded material could

be left bulked. This occurs for example where land is
regraded after highwall coalmining in Pennsylvania, where
the spoil is excavated and thrown back by dragline and the
surface subsequently regraded with bulldozers. The

increase in height immediately after restoration is often
from 5 - 10% of the depth of the excavation.

5.6 Summary

The chapter includes a suggested checklist for landscape
survey for derelict landscapes, and observations on

suitable scales and contour intervals for different sites and
conditions based on the experience of the research

project. Some general conclusions from the various sections
of the chapter can be made as follows.

(a)Survey. The aerial method of survey, which is continually
improving, is likely to be best for derelict landscapes
which are topographically complex to obtain the
desired degree of accuracy and detail. By the
simultaneous flying of a number of sites the cost per

55

hectare can be brought down to a level which might be
competitive with ground survey in average conditions.

(b) There is particular reason to investigate underground and
overhead services as these may limit the extent of
regrading. The presence of old colliery workings and
other unmapped objects needs special attention.

(c) Particular emphasis is laid on the need for careful study
of geochemical conditions, and the early employment
of geotechnical and soil science consultants in
reclamation projects is strongly recommended.

(d)Except on small sites with simple problems, calculation
of regrading is most efficiently undertaken using a
cross-section method adapted to computer use. The
application of other methods to the computer and its
extension into the field of design is under study in a
number of centres.

(e)The most appropriate machine for regrading colliery
shale is the rubber tyred motorised scraper, different
sizes being selected according to the site.

References

Barnard, E. (1965) A Landscape plan for recreation
areas. ‘Developing the rural landscape to balance
the increasing urbanisation of countries’. 1.U.C.N.
Landscape Planning Committee, Newcastle upon
Tyne, pp. 6-9.

Carruthers and Cowan (1966) Planning the restoration
of an open cast coal site, paper to the Operational
Research Society, Annual Conference.

Clark, David (1949) Plane and Geodetic Surveying.(4th
ed. revised and enlarged by Glendinuing) Vol. 1.
Constable & Co. London. pp. 374-413.

Cowling (1968) Highway Design. Jour. Inst. Highway
Engineers. pp. 33-40.

56

Craig Johnson (1965) Practical Operating Procedures for
Progressive Rehabilitation of Sand and Gravel Sites.
University of Illinois National Sand and Gravel
Association Project No. 2.

Craig, W.G. & Burns, J. (1967) Digital Ground Models
in Highway location and Geometric Design - a
review of types of models and studies of accuracy of
the square grid type. Road Research Laboratory.
T.N. No. 151.

Hackett, B. (1967) Earthworks and ground modelling.
Institute of Landscape Architects. Techniques of
Landscape Architecture. A. Weddle Ed. London
Heinemann, pp. 55-72.

Lowe, Young & Lister (1967) A computer system for
highway design. Journal of Institution of Highway
Engineers. pp. 28-36.

MeMillan, T.C.S. (1965) Computer Roadworks System.
Sir Robert McAlpine & Sons Ltd.

Middleton & Chadwick (1955) A Treatise on Surveying.
6th Edn. Vol. 1. E.F.N. Spon. London. pp. 368-376.

Richardson, J.A. & Greenwood, E.F. (1967) Soil moisture
tension in relation to plant colonisation of pit heaps.
Proceedings of the University of Newcastle upon
Tyne Philosophical Society. Vol. 1. No. 9. pp. 129-163.

Riddell & Downing (Eds) (1967) Papers on landscape
planning, survey and appreciation, presented to the
Institute of Landscape Architects Annual Conference,
1967. Planning Outlook, New Series, Vol. IV 92 pp.

Roberts & Stothard (1968) Use of computers for road design
Journal of Institute of Civil Engineers. Paper No.
7133. pp. 105-127.

Vyle, C.J. (1967) Information Sheet concerning Landscupe
Survey and Analysis. Newcastle upon Tyne.

Whyte, W.S. (1969) Basic Metric Surveying. Butterworth,
London.

Chapter 6 Special problems

based on the work of M.F. Downing and C.J. Vyle

The largest part of the research effort by the University
team was directed to the problems likely to be met on
many sites in spoil movement, the development of a soil
cover, and to surface drainage and vegetational cover. These
are the subject of other chapters in this Volume. Neverthe-
less, several special problems came to light which, although
not common to all sites as with the aforementioned, were
considered to be sufficiently important to justify including
them in the research programme.

6.1 Spoil materials
6.1.1 Fused materials

Much colliery waste has high levels of combustible and
pyritic material giving rise to high temperatures and
subsequent ignition of the waste heaps to form red shale.
Where this shale contains quantities of siliceous material,
the intense heat of burning may result in the formation of
large volumes of material fused together (Fig.6.1). The
problems of dealing with hot and burning material are
dealt with in section 6.4.

Fused material is extremely difficult to handle by machine,
and laborious to break down by hand. In the sites allocated
for research purposes, such material exists at Haswell
Colliery and Windy Nook. The former site had to be with-
drawn from the research programme because of administra
tive difficulties, and work had not progressed to grading
stage on the latter site at the time of writing. At the other
sites, the fused material, when present, was in sizes which
could be handled or broken down by machines. It is
expected that it will be possible to report further at a later
date when the work at Windy Nook is in progress.

The investigations that were made on sites elsewhere
indicated that fused material cannot easily be broken
down by earth moving machines, the blades rebounding
from the material. Where explosives have been used, the
explosion has been absorbed in the material without much
effect upon it. One method that has been successful is to
saturate the fused material with water prior to anticipated
frosts, leaving frost action to do the work. Bearing these

difficulties in mind, it is recommended that, where possible,

the design for the reclaimed landscape should be such that
the fused areas are covered with other material, perhaps to
form high places in the new topography and thus obviating
the need for the saturation technique.

At the Windy Nook site, there is evidence that some of the
fused material is in the form of independent masses or
‘boulders’, and may be dislodged in the course of grading
operations, and thus endanger men and machines. The
solution to this problem lies in adequate precautions on
the part of the contractor when handling the material. The

grading of the majority of sites is likely to be sich that
small changes of level and easy gradients are achieved. If
special land form effects are required, it would be necessary
to take precautions regarding the dislodgement of large
masses of fused material.

6.1.2 Sandy materials and slurry

A well known hazard in earth moving operations is the
presence of running sand or material consisting of particles
with a low absorbency rating, either because of its unstabk
characteristics when excavated or deposited, or because of
the difficulty of transporting non-cohesive material. At the
Roddymoor site, this type of material was met in
excavating a watercourse, and movement by dragline,
instead of the pushing action of a bulldozer, was found to
be successful.

Slurry, a very fine material with a coal dust content which
settles in slurry ponds with the recirculation of water in coal
washing plants, is difficult to handle because of its clay-
like properties; its presence would normally suggest that the
basic rates for earth moving should be increased unless it
can be kept dry. An experiment was carried out at the
Roddymoor site using red shale, deposited 0.75m (2ft 6in)
in thickness, to form a haul road around the perimeter of
the slurry area; the machines were then operated without
undue difficulty from the haul road inwards, scraping the
shale into the slurry area.

6.1.3 Materials from demolition

Materials from derelict buildings and engineering plant are
likely to be dealt with in accordance with normal demoli-
tion practice. But two special problems occurred on some
of the research sites, for which experiments were instituted
to find solutions. First, during the expected lowering of new
water-course beds as they performed the task of collecting
and taking surface water away, foundations or bulldozed
sections of walls came to light beneath the spoil and altered
the flow of water so that erosion started in the sides of the
water-course (Fig. 6.3).The situation was aggravated by
flash floods arising from open-cast coal operations on an
adjoining site. The recommendations for dealing with this
sort of problem are given in Chapter 7. Second, several
tunnels formerly carrying surface water, and no doubt
pumped water from the mine, were encountered in the
course of grading and cultivation operations at the Roddy-
moor site. The best machine for dealing with this problem
was found to be a bladed bulldozer with subsequent
tamping (Fig. 6.2). This was followed by scraping and
grading spoil material over the tamped brickwork of the
tunnels to a depth which is recommended at 0.3m (1 ft Oin)
minimum and a preferred depth of 1.0m (3ft Oin).

57

Fig.6.1 Fused material lying in a dangerous position at the Fig 6.2 Bulldozer spreading thin layer of coke breeze over
Windy Nook site. The dislodgement of large masses needs _ consolidated brick tunnels Foreground shows sections of
to be handled with particular care in grading operations. tunnel still requiring to be broken and covered.

4

~

> ae

Fig. 6.3 An example of the exposure of old foundations during the erosion process of a new watercourse. Recommendations
for dealing with this problem are given in Chapter 7.

58

6.1.4 Conveyance of materials

There will be occasions when the removal of some spoil
material from the site may be a solution to a regrading
problem, especially when the material is of greater use
elsewhere. At the Windy Nook experimental site, one
possible design solution depended upon the removal of
some material to fill a riverside dock some 12.8 kilometres
(8 miles) away. This idea was eventually abandoned, but as
a result of investigations, the following matters arose:

(a) Transport of large quantities by road may meet with
objection from residents, the local authority and the
police. Even the transportation of 1000 yd3 of
material is likely to generate 200 return journeys with
their attendant noise, dirt and danger.

(b) The transportation of spoil material by pit railway is
likely to be cheap, but only if there is an existing
direct link between point of loading and point of
deposition.

(c) The transporting of spoil material in water by pipe
line is an economic proposition compared with re-
moval by other methods, if land can be made
available for the pipeline, and the material is
sufficiently fine. If the spoil has to be crushed before
passing into the pipeline, the cost is likely to render
this method of transportation too costly. The
economics of the method depend on having a relative-
ly valuable material in sufficient quantity. A coal
plant in Ohio operates a pipeline of this nature trans-
porting fine coal in suspension over 60 miles.

6.2 Topsoil preservation

Topsoil and subsoil preservation, although a simple tech-
nical problem on conventional sites, is difficult and tedious
on most derelict sites. Frequently, the topsoil has been
masked with other debris and is not easily recognisable, but
proper soil surveys should overcome this problem. When
good soil is available, it is often in small areas and laden
with debris. Also, in areas where colliery spoil has lain
undisturbed for a number of years, it is probably beginning
to develop qualities associated with conventional soils.
Thus, the specification should identify separately these
various areas in order to ensure the soils are notlostin the
mélée of operations and should make it clear that small
machines are to be used, possibly with some handwork,
although the latter can be costly. The importance of
retaining every cubic metre of spoil material which has
some degree of soil fertility cannot be over emphasised;
even 25mm (1 in) thickness of such material can in theory
assist the development of a sward. The spreading of such

a small thickness however, would require expensive
distribution techniques, such as the initial preparation of

a smoothly graded surface and the careful planning of the
use of plant to avoid mixing the fertile material with the
spoil material to a depth where its benefit is lost.

6.2.1 Topsoil stripping and spreading

In the various handling operations for topsoil stripping and
spreading that were observed at the various research sites,
the following difficulties were met and the manner in which
they were overcome is also described:

(a) At the Roddymoor site, the starting date in the
winter gave low tender prices because of the diffi-

culty of working elsewhere on normal sites, but as a
result the topsoil was stripped and stacked when in a
frozen condition. Thus, when spreading took place,
the material was extremely wet and difficult to
handle. To avoid this problem, particular care needs
to be taken to avoid stripping during frosts, although,
as at Roddymoor, it is not always practicable to
arrange the phasing to avoid likely frost months.

(b) Enquiries made into the particular circumstances
arising from the working conditions on reclamation
contracts over large areas indicated that, even if the
frost conditions referred to could be avoided, it is
unlikely that the various operations can be phased
to bring topsoil stripping and spreading within fine
weather periods. Thus, material may often be wet
and heavy to handle. If the timing of a project is
such that topsoil stripping must take place in the
summer and remain in a heap all winter, the temp-
orary covering of the heap with a grass and clover
crop would improve the handling qualities of the
soil, and incidentally reduce weedgrowth.

The assessment made of the use of different
machines showed that the use of tractor-drawn
scrapers gave an even distribution of topsoil. At

the Big Waters site, stripping and spreading took
place during May to July; even so, it was found that
the wheeled tractors had a ‘bouncing’ action when
distributing the topsoil in thin layers. In some places
this led to smearing and compaction with a damaging
effect on soil structure, requiring a ripping operation
to break up the resultant pan.

(c) Over one part of the Roddymoor site, the nature of
the spoil material left at the surface after grading
was considered unlikely to produce conditions suit-
able for plant growth after the various treatments
resulting from the experimental work described in
Chapter 8. It was possible to arrange for some
boulder clay drift to be imported from an adjoining
opencast site for use as a top layer which provided a
suitable medium after fertiliser and cultivation
treatments.

6.3 Dust blow

Wind, rain and the physica! nature of the spoil material are
variants upon which the likelihood of dust clouds will
depend (Fig 6.4). For example, whereas difficulties were
anticipated at Roddymoor because some of the material
(especially the red shale) was fine enough to give rise to dust,
the damp winter months when the earth moving was carried
out contributed to the fact that the fine material did not
blow away. A combination of both wind and rain is likely to
assist working when there is a potential dust hazard coupled
with steaming from hot areas. The greater problem on the
Roddymoor site was the steaming effect due to the damp
atmosphere upon the warm spots as they were exposed (Fig
6.5).

Some spoil materials are also prone to produce dust during
cultivation, but this was found to be lessened by selecting
weather conditions of light rain and little wind. On sites
which are very close to densely built-up areas, the dust
problem can be reduced by lightly spraying a mist of water
from a mounted container in front of the path of the culti-
vation equipment.

59

the design of the reclaimed landscape; for

unds at the perimeter or by locating the

spread of available topsoil in areas from which dust would

adjoining areas. Design limitations of this
ture will, however, require careful consideration in case

they lead eventually to a less satisfactory landscape.

mended that provisional items should be put in

act to cover (a) restricting operations up to an
nit while dust blow conditions are unfavourable
machines from one part of a site to open
up another part until conditions are more favourable and

(c) providing mobile water spray vehicles.

irawl

6.4 Hot areas and combustion

A study of the literature revealed that while a great deal is
known about the conditions leading to spontaneous
combustion in coal mines, there is little documentation on
spontaneous ignition in waste heaps. Most heaps associated
with coal mining contain carbonaceous shale, and coal in
the form of dust and small lumps, as well as hard stone. The
most likely situation for spontaneous ignition occurs in
pockets of loosely-packed material with a substantial coal
content along with iron pyrites and/or organic residues.

6.4.1 Investigations

The necessity for investigating and making available know-

ledge about this particular problem is evident in the danger
to men working on reclamation contracts, in the possibility
of fires breaking out after the work is complete, and in the
effect of fumes upon people, animals and vegetation in the
surrounding areas.

The surveys of existing conditions at the experimental sites
were supplemented by investigations specifically concerned
with heating in heaps, made by Consulting Engineers. These
included:

(a) Observations of heating and ignition by studying the

conditions over the surface.

(b) Temperature readings at the surface, and taken in

shallow boreholes Im (3ft 3in) deep at regular dis-
tances.

(c) Deep bore holes to ascertain temperatures within the

waste material. These should be carefully back-filled
and consolidated after taking the temperature readings
to avoid creating a chimney effect, allowing air to
increase heating or start ignition.

(d) An analysis of exuding gases.

Fig. 6.5 A dramatic example of the steam clouds which can arise from hot areas as
they become exposed during damp atmospheric conditions.

Fig. 6.4 A temporary problem with grading operations in some reclamation projects is the raising of dust clouds by earth
moving machines. This illustration indicates the considerable distances over which the nuisance may occur.

60

(e) The content of the waste heaps as revealed by the
material from the boreholes.

(f) Moisture content, loss of weight on ignition, total free
sulphur, and sulphur trioxide tests.

In the case of (b) it was found that the prevailing weather
conditions had a marked effect upon the temperature read-
ings due to very great fluctuations at the surface, and this
fact must be taken into account in assessing the ignition
problem. The temperatures varied considerably in different
places and at different depths on the sites investigated, the
highest being 410°C at a depth of 1.8m (6ft Oin).

6.4.2 Ignition
It is advisable to regard all waste heaps arising from the coal

industry as having the potential for ignition. Some unburned

heaps may have rising internal temperatures over several
decades before ignition becomes apparent externally. At
Tanfield Lea, near Stanley, Co. Durham, a low heap ignited
after 40 years lying dormant, apparently as a result of slow
heating to ignition temperature. Other heaps may not
ignite until after spoil moving operations have taken place
when pockets of a high coal content may be the sources
for ignition to occur. Nor should it be assumed that an
apparently burnt heap - to all intents and purposes red
shale or other burnt material - is free of pockets of coal or
carbonaceous shale.

Attention is also drawn to the potential danger of levelled
spoil heaps which provide what appears to be a flat area
suitable for housing or industry. The following examples
explain the latent danger.

(a) In a housing area on a levelled spoil heap at Barlow,
between Winlaton and Blaydon, Co. Durham, an
occupier lit a bonfire which led to a general con-
flagration of the ground in his garden.

(b) Paint waste burnt on a paint factory site adjoining
Ouston East heap at Birtley, Co. Durham, set the
heap on fire.

(c) On the Big Waters Experimental site, surface fires
which broke out from time to time were attributed
to children lighting small fires for camp cooking.
These had to be extinguished by the Fire Brigade.

The information produced by the investigations referred
to is essential at the design stage in order that provisions
may be made in the design to reduce the fire risk to a
minimum, and to aid contractors in assessing to what
extent the fire risk must be taken into account in their
methods of working.

6.4.3 Precautions to reduce fire risk

The first problem likely to be met in landscape reclamation
when fire risk is present is that of disturbing the status quo.
In some situations, it may be anticipated that a spoil heap
will burn slowly over a long period of time, as was the case
near Stanley where the heap has burned for over 30 years,
despite determined attempts to prevent this by quenching
with water by the N.C.B. Once disturbance takes place, the
process can be aggravated to an extent where earth moving
operations may have to be suspended before atmospheric

conditions for those living in the district became intolerable,

or excessive dangers to the plant operators are incurred.
When excavating hot or burning heaps it is inadvisable to
work over the top of underground fires; besides the dangers

of fumes, including those of gas explosions and restriction
of visibility, there is the likelihood that cavities may be
created as the result of combustion of the carbonaceous
material. On the other hand, excavation at the base of the
heap may result in permitting the updraught of currents
through it, in such a way that heating and ignition is stim-
ulated. Nevertheless, this may be the safer way of excavation
provided falls of material can be avoided. Lateral excavation
at different levels, preferably at the side sheltered from the
seasonal prevailing wind at the time of operation, may be a
satisfactory solution.

6.4.4 State of spoil heaps

If, as a result of temperature borings, it is established that
the spoil heap is at a temperature below the ignition stage,
then any re-distribution of the spoil is best handled from
the top of the heap downwards, thus avoiding the creation
of draught effects. If there is a likelihood of ignition, the
temperature may be kept down by pumping water on to
the surface as the work proceeds, though this often gives
rise to steam, making conditions uncomfortable to work in
and reducing visibility. Water pumped on to hot heaps
may also give rise to steam explosions, when an accumul-
ation of steam takes place below the surface.

The physical condition of spoil heaps alters with the stage
of burning. First, before ignition, they are more or less
physically stable, depending on the method of deposition
and degree of compaction. Second, during and soon after
ignition, voids may develop. Third, some years after burn-
ing has ceased, the voids may have filled through settle-
ment and the heap becomes comparatively stable. In the
second condition, the normal method of operating
machines from the top downwards can be particularly
dangerous, as there is the possibility, already indicated,
of men and machines falling into the voids, coupled with
danger from fumes. Burning material should be quenched
and distributed in 300mm (1 ft) thick layers with 300mm
(lft) thick sealing layers of lime, chalk or clay between. It
is stressed that sand is not sufficiently impermeable to be
used as a sealing material.

6.4.5 Roddymoor

At the Roddymoor site, investigations into the spontaneous
ignition situation forecasted that temperatures of about
200°C would be experienced in a small part of the waste
heap, and of about 150°C generally over large volumes of
material - mainly between boreholes 2 and 4. Also, that
this hot material would cool rapidly after exposure. It

was, therefore, considered advisable to use a long-boomed
dragline or face shovel, though with care a tracked machine
could be used. Machines with rubber tyres were not
recommended. In fact, it was possible to use a tracked bull-
dozer to push out the hot material and spread it to cool.
Within only a few minutes of spreading, it was cool enough
to be transported by tractor-towed scrapers.

6.4.6 Percy Pit

Unless the precaution is taken of layering combustible
material the potential danger that fires may break out in
the newly-contoured landscape is likely to remain. One
solution is to remove the combustible material by screening
and washing, but this is expensive unless the contractor can
be certain that the coal content is sufficient and can be
disposed of quickly at a price giving a reasonable return for

61

his outlay, taking account of the delay to the reclamation
contract. This possibility was investigated at the Percy Pit
site and was found to be uneconomic as a separate opera-
tion, largely because it would have been necessary to move
the greater proportion of the material twice in order to
achieve a satisfactory land form due to the restricted nature
of the site.

6.4.7 Big Waters

Another method for overcoming the problem of spontan-
eous ignition was investigated at the Big Waters site. The
experiment consisted in the isolation of a burning area by
means of a ditch 2.4m (8ft) wide dug down to the original
ground level. The ditch was filled with clay, and a cover of
a similar inert material laid over the isolated area to a
minimum depth of 1.8m (6ft). This experiment has proved
successful. An interesting small point is that a small
amount of hot material from another part of the site was
removed to the experimental area and spread on the larger
burning areas, before the clay cover, thus restricting the
need for remedial work to one location.

6.4.8 Safety measures

On the results of various trials in regard to the procedure
for grading in hot areas, we recommend that the following
safety measures be taken:

(a) Acontractor experienced in the movement of
burning heaps should, if possible, be employed.

(b) High temperature reading thermometers should be
kept on site.

(c) Warning disc badges should be worn by plant opera-
tives to detect carbon monoxide, a further disc being
mounted on the instrument panel in the operating
cabin. Badges should also be worn by site personnel
who are liable to go near areas of hot material. The
badges are similar in style to the types worn by
personnel in the nuclear industry and are inexpen-
sive.

(d) Care should be observed with fuel on machines
operating in hot areas, and in the use of rubber tyred
vehicles. Manufacturers’ recommendations indicate
that most scraper tyres can be used where tempera-
tures do not exceed 200°C. Few contractors will
need to be reminded of the need for care with scraper
tyres in view of their high cost - of the order of
£1000 each for larger scrapers.

(e) Operators and personnel should have a basic know-
ledge of the hazards of toxic gases as well as the
symptoms and initial treatment when affected, no
matter how remote the likelihood may appear.

(f) Special care should be exercised in warm still weather
when working hot areas.

(g) Thermocouples should be inserted into the area when
it is reduced to its designed level, if any particular
dangers are anticipated, to a depth of about 1.2m

(4ft). The number would depend on the site condition.

Daily readings should be taken and recorded as the
scheme proceeds.

(h) On completion of the scheme an experienced observer
should visit the site monthly for a period of a year,
and thereafter at longer intervals for a period of up to

62

five years. The presence of heating 1s often shown by
damage to the herbage, which may become discolour-
ed and quickly die off; this is usually the result of
the release of gases.

6.5 Toxic gases

Associated with the problem of spontaneous combustion is
that of the toxic gases which are often generated in waste
heaps. The main gases occurring on the experimental sites
were:

(a) Carbon dioxide, which is dangerous in concentration
since it dilutes the available oxygen supply to the
lungs, and has no smell. In the open, however, little
hazard is presented.

(b) Sulphur dioxide and trioxide, which in diluted
quantities will irritate the lungs and are liable to
cause pneumonia; however, because of the irritant
character, the gases are self advertising when inhaled.

(c) Hydrogen sulphide, even in diluted concentrations, is
characterised by its smell of rotten eggs, and therefore
makes its presence self-evident. It is almost as toxic
as hydrogen cyanide (prussic acid gas). In very diluted
concentrations over a period of time it can cause head-
aches and various other symptoms.

(d) Carbon monoxide, which is described as a toxic gas
capable of destroying the red blood cells; its effect is
more lasting than the dioxide. In diluted concentra-
tions, it produces the symptoms as hydrogen sulphide.
It has the disadvantage of having no smell and a
cumulative effect.

There is likely to be a considerable dilution of the gases on
sites, but plant operators should be warned about the
dangers, and a strict watch kept on the situation and a
strict control on the periods of working.

6.6 Pollution

Although such sources of pollution as burning from spon-
taneous ignition and chemical action may be controlled or
physically contained, there is always the possibility that the
water draining from a site may be polluted through the
seepage of water down through the waste material and
eventually to the water-courses draining the site. It has
been found, for example, that polluted water from a waste
heap material can upset the biological balance of sewage
treatment plants and the chemicals leaking out can, if in
sufficient concentration, kill off the bacteria which break
down the sewage. The best way of preventing this type of
pollution is through careful design of the reclaimed land-
scape. The slopes and disposition of materials should be
such that surface water is unlikely to reach a source of
pollution and then be able to surface again without a long

journey through virgin subsoil or strata which act as filters.
This problem was particularly important at the Big Waters
site where one objective was to produce and maintain
conditions to support fish and other types of wildlife. To
date, the design of levels and layers of inert material have
proved successful, and the only observable pollutant comes
from a nearby project which drains into a stream entering
the site.

6.7 Procedural problems

During the course of setting up the experimental sites, a
number of procedural problems arose. These are not
directly relevant to the design and technical problems of
the research, but are listed for information:

(a)
(b)

(c)

Services and other undergound elements may be
encountered for which no record exists.

The contractor may take risks by departure without
permission from a precaution adequately covered

in the specification. The contractor is clearly respon-
sible for the risk but frequently this involves pro-
tracted discussion and extra work by the ‘engineer’,
the client and other affected bodies.

The procedures for giving notice of works to be
carried out to all the many persons and authorities
concerned are involved. To obviate omissions a check
list similar to that of the Reclamation Section of the
Durham County Planning Department is a wise
provision to ensure that all likely persons and author-
ities are notified.

6.8 Conclusions

(a)

The materials likely to found are so variable that site
surveys including a large number of boreholes may

(b)

(c)

(g)

(h)

not give a representative picture of the contents of
heaps.

Appropriate design of reclaimed landscape can often
reduce the problems caused by difficult materials.

If it were possible to disclose by survey every under-
ground hazard, the cost would be prohibitive. If

extra expenditure is incurred in the contract work

on some sites through the presence of objects undetec-
ted at the survey stage, it should be recognized that
even the most exhaustive surveys may fail to bring

all potential hazards to light.

The preservation and spreading of topsoil, even if
only small quantities are available, is of paramount
value in the creation of a medium for plant growth.

The unpleasant effects of noise and dust during
reclamation operations can often be mitigated by the
design and by operational techniques.

Further research is needed into the problems of
controlling ignition in waste material, and into fore-
casting the likelihood of ignition.

Safety measures at the highest standards should be
adopted for operatives using plant on waste material.

Pollution arising from within reclaimed sites can
often be minimised or even eliminated by suitable
design measures.

63

Chapter 7 Land drainage

by M.F. Downing

7.1 Introduction

It has needed comparatively little investigation of other
reclamation schemes and experience on research project
contracts to establish that attention to the adequate
drainage of reclamation sites is a primary requirement of
any design for returning the land to a fertile state. The
final drainage pattern of sites is, however, not the only
drainage problem which needs to be considered. The char-
acteristics of the material and drainage of the site must be
foreseen and catered for at all times, from the inception of
operations to the consolidation of a mature landscape, and
this involves a changing or phased drainage plan.

Surface water and subsoil drainage requirements in normal
ground conditions are set out in principle in the British
Standard Code of Practice No. 303 (1952).

Engineers will be aware of the seven subheadings set out in
Paragraph 103 of the code, entitled “exchange of inform-
ation’, enumerating the basic information necessary before
drainage work is carried out.

7.1.1 Adaptation of standard information
requirements to reclamation sites

The relevance of some of the information as listed in the
code may not initially appear to be so direct and import-
ant in the case of reclamation sites. For example, the water
table of derelict mounds and valleys of deposited material
may bear no relation to the natural ground watertables or
to the future water status of the regraded site. Also, the
nature of the strata of natural ground underlying the site
may appear to have little relevance to the regrading. This
however, is not the case, and although the factors may vary
in importance on reclaimed sites it is just as necessary to
take account of them all as when dealing with the drainage
of natural forms. The effects of regrading and perhaps
covering impervious strata can result in the development of
spring line conditions, or of wet and unstable areas. The
movement of water within the material can result in erosion
and internal collapses, and this will happen where lateral
water movement is induced as a result of the influence of
the underlying strata. It is not necessary to underline the
need to deal adequately with known streams or watercourses
which may be affected by the regrading, though the fact
that some of them may be seasonal and therefore not
immediately apparent during initial site inspection should
be emphasised.

The watertable of adjoining land and of the land in
question is a matter which needs particular attention. The
regrading of material will inevitably have some effect on the
water table around the site, and this must be studied for its
effect on soil and water status, particularly its indirect
effect on existing trees which could be adversely affected
by either raising or lowering the watertable.

64

7.1.2 Phases of reclamation site drainage

Site drainage on reclaimed land can be considered within
three distinct phases as follows:

(a) Drainage during contract operations.

(b) Special provisions to ensure simultaneous mainten-
ance of stability and free drainage during site
establishment.

(c) Terminal drainage.

If the framework of the terminal drainage system of a site
can be so designed that it provides adequately for the main-
tenance of good site conditions in the intervening contract
and establishment periods, this is an ideal solution. Initial
drainage provision will consist of open ditches, easily
cleared of silt and these may be left as such in the final
state of the design, or may be filled with rubble or add-
itionally piped.

7.1.3 Instability of colliery waste

Sir John Russell (1950) has enunciated the principle that
‘the success of drainage operations depends on the stability
of the soil’. This statement has particular relevance when
dealing with regraded land involving waste material.

Natural land forms in the majority of Great Britain, and
certainly with minor exceptions in the north east of
England, have achieved a reasonable degree of geological
stability and may be described as being predominantly in
the compaction stage of the denudation and deposition
cycle described by geomorphologists (Bundred 1969). The
processes of weathering and denudation effected by wind,
water and extremes of temperature are well described in
standard textbooks of geology. The principle that erosion
will continue towards the creation of a flat plane, in any
situation where the downward flow of water or the effect
of gravity can overcome the stability of the surface material,
is commonly understood. The fact that colliery waste is
evidently highly subject to erosion may be due to its being
inherently less stable than natural soils or to the high degree
of impermeability of material when compacted by contract-
ors heavy plant causing a high percentage run off. It follows,
however, that in any situation where work with colliery
waste is involved, a particularly careful watch must be kept
on the design of slopes and situations which are especially
liable to erosion. These will be dealt with in some detail in
the following paragraphs.

7.1.4 Impermeability of colliery waste

In the operational stage the amount of percolation is very
low and run-off is high. A surface covered with vegetation
such as grass is generally regarded for drainage calculation
purposes as having a run off of approximately 10% of the

total rainfall. In many cases, however, during operations,
the run off from shale will be more nearly comparable with
the theoretical percentage impermeability of footpaths,
namely between 50 and 75%. Indeed many designers prefer
to base their calculations on the assumption of 100% run
off as allowed for buildings. Apart from the characteristics
of impermeability or run off arising from the nature of the
soil and the vegetational cover, the ratio of run off to
percolation depends on the rate of precipitation, and the
angle of slope. It is therefore necessary to ensure that the
angles of slope provided are satisfactory both in the long
and short term.

7.1.5 Calculations of run off

It is important to emphasise that calculations of drainage
provision should be based on the worst conditions anti-
cipated on the site during the operating and subsequent
establishment period involving a greater provision than
would be required for the established site. This over
provision is greatly preferable to the damage which can
follow inadequate initial drainage measures. A number of
formulae exist for the calculation of run off from areas of
land, and here again engineers are familiar with problems of
run off, rainfall intensity and storm duration, and will
select their methods to suit their purposes. It may be useful
to draw attention to the precise run off values given by the
American writer Seelye (1951) which differentiate between
clay, loam and sand, dependent on the vegetation cover.

Related experience on reclamation sites has emphasised the
need to calculate using a high coefficient of run off
approaching that of buildings as indicated in the previous
section, and certainly not less than that for roads and pave-
ments if trouble is not to be experienced in the initial
establishment period.

7.2 Drainage during contract operation

Attention to drainage conditions on the site during the
operation of the contract is important from two points of
view, first the protection of works and second the protec-
tion of adjoining property.

7.2.1 Protection of works

The efficient operation of the works can be badly impeded
by poor drainage, standing water, the formation of erosion
gulleys, and the deposition of silt in low lying areas. Failure
to take adequate precautions during the operational period
when the site is likely to be completely devoid of vegetation,
and run off potential is at its highest anticipated level, can
result in this type of damage, as has been stressed. Where
excavation of material results in temporary steep slopes or
sheer faces, sudden high volume precipitation can result in
flow slides or slips. Most of the precautions necessary for
this type of work are well known to those concerned with
earthworks. Experience in Durham County indicates that
the worst period for run off and erosion is after grading and
spreading of top soil and before the establishment of vege-
tation.

The dangers of soil creep, slides of fragmental detritus and
rock, and deep rotational shear slips, and methods to pre
vent their occurrence and rectify their effects, are set out
in the British Standard Code of Practice for Earthworks.
All these or very similar phenomena may occur in the arti-
ficial conditions of deposition of colliery waste, and may
indeed be aggravated by its peculiar liability to erosion.

7.2.2 The protection of adjoining property

During the operational period damage by run off can be
caused to adjoining land. It is advisable to consider what
would be the likely effect of the worst possible rainfall
conditions, based on a 1 year cycle of records, and to plan
the site operations accordingly. A higher degree of safety
would be achieved by the use of a longer cycle but such a
counsel of perfection is not always possible and some ele-
ment of calculated risk is acceptable.

On very large sites, for example those exceeding several
hundred hectares, it may be desirable to adopt a higher
standard of safety based on a longer cycle of rainfall
records, say 7 to 10 years. In practical terms, on urban
sites where the drainage is into main sewers, the capacity
of these will strongly influence the design of the site
drainage. A limited surcharging of the main surface water
sewage system may be accepted, provided that the antici-
pated discharge does not exceed the capacity of the
system by too great an amount; the risk to adjoining
property is comparatively remote and the provision of
on-site stilling ponds permits the temporary retention of
water on site. A high degree of care is needed where, on
reclamation sites adjoining urban areas, steep slopes make
for a high potential rate of run off.

Consideration of the duration of the operation, and the

time of year, from which anticipated rainfall can be gauged,
are further factors which help to give a balanced picture of
the precautions which are required to be taken. Other risks
which might occur in special situations, and must be toreseen
and assessed, are: the washing of heavy metal or toxic water
into water catchment areas, or on to agricultural land; the
silting up of agricultural drainage channels and even the
flooding of excavations into adjoining opencast coal
workings.

Prevention of damage and flooding on adjoining land can
usually be achieved by the temporary provision of bunds
which operate in the same way as the stilling ponds and
behind which storm water can be stored or diverted to drain
away slowly depending on the flow capacity of the available
drainage outflows. Frequently this requires no more than
the limited operation of a bulldozer blade to create a
shallow v-shaped ridge and furrow to cut off the flow of
surface water from high ground to outfall. On such large
sites or extensive slopes it may be necessary to construct
several such ditches. The permanent protection of adjoining
property often calls for the digging of cut off ditches along
the boundary line of a reclamation site and this work can
generally be carried out as an early item in the reclamation
works so that some protection is given by it during oper-
ations. This is possible because it is desirable in practically
all cases to grade reclaimed areas to merge with existing
ground levels on adjoining land. The presence of such a
ditch, and open ditches across the site does not obviate the
necessity for stilling ponds and may in severe storm condi-
tions make such holding devices even more essential. The
ditches will tend to speed up the movement of water from
the far corners of the site to the outfalls causing greater
concentration than there would be without them.

The necessity for protection during the contract operations
is underlined by the experience recorded at Brancepeth heap
near Crook, Co. Durham, where high rainfall occurred at a
time when the top-soiled areas of the site had just been
seeded. Conditions were such that very high run off occurr-
ed and this was discharged into the local drainage system.

65

Due to a combination of local circumstances, the volume
was too great for the system and the water flowed over the
lower parts of the site temporarily flooding the village street.

7.2.3 Application to research sites

The maintenance of satisfactory site conditions during the
operation of a contract is principally the responsibility of

the contractor. This is clearly set out in the conditions of
contract in so far as any loss, damage, or injury is concerned,
whether to persons or to property. Any specific protective
measures required both during the period of the contract or
while the site is becoming established should be fully explain-
ed to the contractor particularly when adjoining property is
concermed.

As far as the operation of the contract is concerned the
contractor will naturally adopt what he regards as the most
efficient and workmanlike procedures necessary to ensure
unimpaired working. This may involve the digging of temp-
orary diversion channels and ditches if the site becomes very
wet, and, of course, ensuring that as far as possible no areas
of low lying land capable of temporary flooding are allowed
to remain any longer than operationally necessary. No major
problems of this nature have been encountered on research
sites during the earth moving operation periods of the vari-
ous contracts. Some problems were met at Roddymoor due
to the presence of slurry material which when wet is diffi-
cult to handle and this points to the need to make special
drainage provision for slurry ponds during contract opera-
tion.

7.3 Special provisions during establishment

The drainage characteristics of both immature and mature
sites are dependent on the earthshaping design and to a
lesser degree on the physical properties of the material
being regraded. In the establishment period, i.e. the period
immediately after operations when the grass sward .and
other vegetation is neither dense nor robust enough to
ensure the stability of the site under all but exceptional
conditions, the damage which cna result from steep slopes
and high run off conditions is more extreme than will be
the case in the mature landscape as has already been stress
ed. The site and the soil are both less stable than they will
be when the landscape matures, but the problem is basically
the same in both situations. It has never been considered
desirable to construct final tite undeérdrainage systems until
regraded land is completely settled, and in any case closed
systems of underdrainage, which rely on the percolation
of water through the soil,do not adequately control the
conditions of high run off and consequent erosion which
occur at this stage. It has also been found that rubble
drains, if completed before vegetation cover is established,
are subject to severe silting. It is, however, essential to ensure
that surface water run off does not result in excessive vol-
umes or high flow speeds over the surface. This means that
drainage by temporary open ditches is employed to reduce
the area of local catchment and prevent the build up of
surface water flows. (Fig.7.1). The ratio-of-percolation to
run off discussed earlier is the significant factor which
changes from the operational stage through the stage of
establishment to the developed conditions of the site.
Mention has been made in Chapter 4 of the theoretical
optimum slope below which no drainage takes place and
above which erosion occurs, and it has been indicated that
land use requirements make the attainment of such slopes.

66

which theoretically ensure perfect drainage, most
uncommon in practice. On all but steep embankments the
rate of percolation can be assisted during the establishment
period by opening up the surface with deep-tined equip-
ment, and this should be considered even though the effect
may be of limited duration as has been suggested by some
workers. This is almost invariably necessary where the
surface has been laid down using the types of heavy earth-
moving machinery now available and commonly employed.

7.3.1 Temporary drainage to cortform to the
permanent pattern

The creation of open channels or similar devices to control
run off of water during the establishment period has already
been discussed, the layout of this work ideally being such
that the channels will ultimately form the submains of the
underdrainage system. Open channels can also be used in
association with the piped system to act as a check on the
water flow and can be constructed with check dams along
their length where the falls and flow potential make this
necessary. Where check dams are used some special constru-
ction may additionally be necessary to prevent scour of the
banks or bed of the channel.

7.3.2 Protection of channels

It is particularly important when designing temporary or
permanent open channels that the instability of shale
materials is taken into account. It is frequently necessary to
take special precautions to ensure that erosion does not take
place in the channels. Where this has not been done, storm
water has cut deeply into the shale in a very few days (see
7.3.4).

The placing of selected materials such as brick rubble,
breeze blocks, stone or concrete in the channel to form a
hard solid bottom not subject to erosion can overcome this
problem and such material is often available on site either
from demolished buildings or from colliery waste heaps.
This method has been adopted in the design of channels at

Percy Pit in particular, and similarly used for remedial works

at Roddymoor as discussed in section 7.3.4.

It is sometimes desirable to open up temporary channels to
counter flash flooding in positions where they are not
subsequently to be incorporated into the final under-drain-
age pattern. In this case it is probably adequate to create
shallow v-shaped trenches or make a furrow with a single
furrow plough, with the furrow on the uphill side of the
field, to check and direct the flow of water, though this
may be difficult where there is a high stone content in the
shale. These temporary features will be kept open for only
one year and allowance should be made in the contract bill
for them to be filled and grassed over during or towards the
end of the maintenance period. There may also be a need
to make similar arrangements for permanent drains which it
is felt desirable to leave open as ditches during the estab-
lishment period, and to complete these after one or two
growing seasons.

7.3.3 Tile drainage and plastic drains

As already indicated it is not generally regarded as desirable
to lay permanent drains on regraded land, for example, after
opencast mining, until it has settled, and this often means
waiting for five years or more from the time of regrading.
Without very careful control the compaction of material on

—

regraded sites is not of guaranteed uniformity such as would

: a 7.3.4 Research sites
be acceptable for structural engineering purposes. The use

of heavy machinery, so common nowadays, achieves a It has been necessary to carry out a number of remedial
degree of consolidation which exceeds that on much activities on site to assist the establishment of vegetation
natural ground, and it may well be that with a minimal and to counter erosion. In particular on the Roddymoor
improvement of supervision a reasonable uniformity of site, the erosion of channels formed in shale has proved to
compaction can be achieved to allow drains to be laid with- be severe in places. This was particularly so where a large
out delays for settlement. This possibility may be assisted discharge of water had been received from higher ground

by the use of plastic drain pipes in long lengths in place of being worked for the extraction of opencast coal. In the
traditional tile drains. main channel, deep erosion had been experienced (Fig. 7.3),

Fig.7.1 Roddymoor, Crook: Temporary open ditches to check surface water run off
N.C.B. (Opencast) Site.

Fig. 7.3.Roddymoor reclamation site: Severe
Fig. 7.2. Roddymoor: Matting laid on bank of main channel to prevent erosion erosion on main drainage channel.

67

and the channel which was excavated at 1.2m wide x 0.9m
deep (4ft wide x 3ft deep) has now eroded in places to a
depth of 3.3m (11ft) below original ground level with an
increase in width varying from 0.6m to 4.8m (2ft to 1 6ft).
The channel has now been lined with large rocks in places
and sand bags, and gabions filled with whinstone have been
used to prevent further erosion in the most seriously
affected lengths of the stream. The use of polypropylene
matting has proved successful in controlling erosion on
embankments, stream banks (Fig.7.2) and, in the case of
small channels with intermittent flows, on the actual
stream bed. This material is laid in sheets secured by
galvanised pins and has a wearing life of several seasons.

As it rots, the intention is that the vegetation will grow
through it to act as the permanent stabilising medium.
Further experiments in the use of this material are contin-
uing. Experience at Roddymoor had underlined the need
to counter scour at points where flow is impeded by
isolated large objects in the stream or channel bed. In these
circumstances silting occurs above the object and scouring
takes place immediately down stream of it. Alternatively,
scouring may act laterally into the stream bank if there is
any weakness at a point where flow is impeded.

7.4 Permanent drains

The permanent drainage system of a reclaimed site must
ensure that no damage occurs in the event of a sudden
storm. It must also be adequate to the task of removing
excessive soil water from the site so that the soil may
remain open and healthy, capable of supporting good plant
growth and human and animal use as required. The degree
of underdrainage provision will depend on the use, angle of
slope and elevation in relation to surrounding ground of the
site in question. For forestry no underdrainage is required,
any problems of damp low lying land are usually adequately
dealt with where it is possible to regrade land to a slope
which enables water to run into ditches at field boundaries.
This it is suggested is a gradient of not less than 1:30 or
1:40. Open ditches may be cut when planting is undertaken,
at suitable intervals of, say, 30 to50 m,and can be left open
permanently.

7.4.1 Use of tile drains

It is only where playing fields are to be constructed that it
is necessary to lay tile drains extensively, because of the
need to achieve relatively flat surfaces which do not allow
for easy surface water run off. Where a long term future use
is to be agricultural arable land then some tile drainage may
be contemplated for a later date.

A good case has been made out by Doubleday (1968-9) for
the inclusion of underdrainage in the early stages of reclam-
ation where a high degree of salinity is encountered in red
shales as occurred at Felling. The provision of underdrainage
will allow leaching to take place at an enhanced rate. When
this occurs it is necessary to delay sowing for a season or
more by which time salinity levels should have dropped to
an acceptable level. The status of the material should,
however, be tested continuously. In areas where there is to
be development for casual recreation, nature reserves, forest
and woodland planting, and special uses such as ski slopes,
variations in topography may call for special drainage
measures.

68

7.4.2 Embankment drainage

Where terraces are separated by embankments it is desirable
to protect the head of the embankment, introducing hill
grips on the actual slopes, and ensuring that the foot is
adequately drained. At the head of embankments and on
steeply sloping terraced sites, the device of a wide shallow
channel acting as a storm bund and collecting water from
the terrace to convey it into the underdrainage system,
may be adopted. These channels may be-designed with tile
drains back filled with rubble in the-base-or-with gulleys

at their lowest point. The hill grips consist of rubble drains,
generally without tiles, not less than 450mm deep (18in),
dug at forty five degrees to the line of maximum slope.
These are connected to a collecting tile drain at the base of
the slope. Experience so far at Roddymoor suggests that
when the slopes are 1:5 or less there is no need for hill grips,
though there may be some advantages in including some
connected to cut off drains at the base where the slope is
particularly long (Fig.7.4). Even with these gradients some
danger exists during the establishment period. At the base
of embankments, tile drains with rubble back fill should be
provided to prevent the development of damp spots. On
some banks the use of flumes to channel water from the
higher level to the lower level may be adopted (Fig.7.5).
This involves careful attention to the detail of the collecting
area at the top of the flume or the system may otherwise
be rendered useless by erosion channels which bypass the
flume.

Subsequent proposals for Felling have introduced a series

of drains parallel to the contours and connected with

closed pipe drains at selected points down extensive slopes,
in place of 45° angled hill grips. These, left open at the early
stage of the contract, and then back filled with rubble and

a pipe are now thought to be more efficient.

Where the frequency of field boundaries permits, the
drainage of a site can be achieved with open ditches. In this
case it is only at the outfall, if it is into a main sewage
system, that any major construction will occur with the
need for a cross wall with a final piped length and a silt trap.

On many sites a new topography consisting of terraces and
embankments will make the laying of drains to a consistent
or near consistent fall a difficult matter though care for this
aspect must be a major consideration in the landscape
design.

7.4.3 Silt traps

The problem of silting is particularly prevalent in reclaimed
colliery waste and there is a need to make complete prov-
ision for silt trap inspection chambers. Additional traps may
be desirable where changes in the rate of flow occur from
fast to slow, and where silt may be deposited. The need for
continual and frequent inspection and clearance of silt traps
especially during the early part of the site development is
discussed in Chapter 6.

7.4.4 Legal requirements

The legal requirements of surface water drainage schemes
are set out briefly in the B.S.C.P. 301 (1952). The powers
of local authorities and rights of owners and occupiers of
property are derived from the Public Health Act 1936.
Where no publicly-owned sewers exist, drains may be dis-
charged into streams or soakaways, provided no nuisance is
caused and no pollution of any watercourse occurs. In such

Fig.7.4 Roddymoor: Main drainage channel.

circumstances, and, in fact, in every case where discharge of
water from reclaimed land is concerned the precise details
of the problem should always be discussed with the Local
Authority and the Water Authority concerned.

7.4.5 Research sites

It is as yet too early to provide any conclusion based on the
permanent drainage characteristics of the research sites. It

is hoped that more useful data may have been obtained by
the time of publication of the second research volume. More
work is, however, still required as indicated in the conclu-
sion.

7.5 Conclusions

Among the important findings of the project are those
concerned with the very significant part played by drainage
operations in the development of any site. Not only must
the site be designed with its ultimate drainage needs in mind
but ample provision must be made for the short term or
development stage of the landscape. This will frequently
result in the inclusion of drainage measures considerably in
excess of those needed for the permanent drainage of the
site, simply to ensure its satisfactory establishment. These
will range from temporary ditches to more substantial tile
drains. In particular, the provision of silt traps to prevent
silting of main drainage systems and watercourses is req-
uired, again principally during the short term development
period of any site. Drainage channels too, must be capable
of being easily cleared in the event of silting.

More work is required by hydrologists into the problems
of pollution emanating from pit heap materials and its
effect on watercourse flora and fauna. The possible dangers
of the discharge of serious pollution on the anaerobic bac-
teria of sewage works should not be ignored. Similarly,

Fig.7.5 Roddymoor: Concrete flume built
on steep slope.

additional detailed studies of the erosion of shales under
site conditions would be a valuable contribution to know-
ledge on landscape reclamation. Measurements to assess
the relationship between precipitation and run off, under
different conditions on shales in unvegetated, partially
vegetated, and completely vegetated conditions would
provide useful information for future drainage calculations.
Information could bé@gained by survey and observation of
the gradients of drainage channels related to volumetric
capacity and degree of compaction of the material, also
affected by related catchment and rainfall intensity and
applied to the design of channels which will not erode
seriously.

References

British Standards Institute ( 1952) B.S. Code of Practice
no. 303. Surface Water and Subsoil Drainage. B.S.1.
London.

British Standards Institute (1952) B.S. Code of Practice no. 301.

Building Drainage. B.S.1. London.

Bundred, J. (1969) Basic Geology for Engineers.
Butterworth, London.

Doubleday, G.P. (1968) Report on the Windynook,
Whitehills Site. Shale Analysis and Suggested
Reclamation Techniques. Unpublished report.

Doubleday, G.P. (1969) Preliminary report on the Soil
Forming Potential of the shale on the Windynook,
Whitehills Site, Felling. University of Newcastle upon
Tyne, Dept. of Soil Science

Russell, Sir EJ. (1950) Soil Conditions and Plant Growth.

Chapters 19 pp. 346-361, 20 pp. 372-384, 22 pp
384-397. 8th ed. Longmans Green, London

Seelye (1963) Design. Data Book for Civil Engineers Vol. 1,
Section 5, Drainage. John Wiley, N.Y.

69

Chapter 8 Soil forming materials:
their nature and assessment

by G.P. Doubleday

8.1 Introduction

On many derelict sites, especially those concerned with
colliery waste, there may be some difficulty in establishing
and maintaining vegetation. This problem can be overcome
either by making the plants ‘fit’ the soil or by making the
soil *fit’ the plants. In the former method the choice of
plants may be narrowed down to a few species or even to a
specially selected ecotype; in the latter approach, as
outlined in this chapter, a diagnosis of the underlying soil
problems is made, coupled with management practices
which encourage the normal healthy growth of a wide
range of plant species.

On most colliery waste the development of a useful soil
only begins at reclamation and unless the process is
controlled in the succeeding years, the site will tend to
revert to its original condition.

8.2 Materials found on derelict sites

Once a site becomes derelict it is frequently used as a
dumping ground for refuse, most of which is totally
unsuitable as a soil forming material. Items such as broken
foundations, scrap iron and timber, domegtic waste etc.
should be removed or buried at a depth so that normal
cultivation practices may proceed without unduly risking
machinery.

This chapter will be confined to the reclamation of stored
soil and shale, these being the most important plant
growth media on sites examined in the project. Of these
two materials, the reclamation of shale is considered more
fully as the problems of reclaiming stored and poor
condition soils have already received considerable attention
in open-cast restoration research.

8.3 Problems associated with the use of stored soil

Many reclamation schemes aimed at returning a derelict pit
heap site to agricultural land follow the same basic
pattern, see Fig. 8.1. The top and sub soils from areas
adjacent to the pit heap may be stripped and then stacked
for periods of several months. After the tip has been
graded out over the stripped areas the soil is returned to

cover as much of the new shale surface as possible. When top

and sub soils are stacked in compact heaps, they undergo
changes which normally involve some deterioration in their
physical condition. Hunter and Currie (1956) examined
these changes in fine textured soils and observed that when
the material was respread it would:

(4a) poach badly under cattle and machinery
(b) give a poor or unstable tilth
(c) be subject to erosion

70

(d) allow only shallow rooting of plants

(e) be subject to cracking in dry weather

(f) _ resist the introduction of earthworms

(g) require a starter application of 3cwt/acre single
superphosphate per acre (i.e. 54 units POs ) in the
first year

(h) require no potash and little nitrogen in the first
year but heavy applications subsequently.

In order to minimize the physical damage, a soil should be
kept stored in a heap for the shortest possible time. When
the material is respread it will require special management
and cannot be expected to behave as if it had never been
disturbed.

8.4 Colliery shale as a soil-forming material

8.4.1 The formation of pit heap materials

The commercially valuable Coal Measures were formed
during the latter part of the Carboniferous System, some
220—280 million years ago. At that time what is now
Northern England was a generally subsiding area periodically
covered by the sea. Although submergence was by a sea,
probably not more that “a few tens of feet deep”

(Westoll, 1968), conditions led to the deposition of
calcareous material which later formed limestone strata.

pit heap

top soil

sub soil

Fig. 8.1 Stages of regrading showing the distribution of
top soil. (Not to scale.)

With the generally south westerly advance of a delta
complex served by rivers from land blocks to the North
and East (Wills, 1951), much argillaceous sediment was
subsequently deposited over the calcareous sea floor. Pons
and Zonneveld (1965) point to the ubiquitous association
of organic material with argillaceous sediments. In
stagnant waters this led to reducing conditions favouring
the formation of finely disseminated iron sulphides. The
orgamic material and sulphides gave the sediment the

grey or black colour so familiar in pit heap shales.

With the seaward advance of the delta front the marine
cover became shallower, reducing conditions changed to
oxidising conditions, and the argillaceous sediments gave
way to sandy material. As the delta formed, deposits
became more heterogeneous, ranging from muddy banks to
pebble and sand filled channels. No doubt the paths of the
distributaries changed from time to time producing
interbedded and reworked material.

Vegetation grew wherever possible, roots and rhizomes
being incorporated into the primitive soil. Aerial growth
was occasionally preserved as peat deposits but was
frequently removed by shifting watercourses or during
inundation by the sea, and incorporated into a new
deposit elsewhere. The frequent reworking of the delta
surface and incorporation of the organic debris gave rise
to the material which subsequently formed the
seatearths often found below coal seams, Moore (1968).

The surface pH of the material would have been 4.5 to

5.5, being conducive to a high rate of biological activity

for which the necessary mineral nutrients would still

have been present. Continued fresh water leaching,
especially in the presence of organic complexing agents, led
to the removal of many cations and to changes in the
mineralogy involving a relative increase in the percentage
of kaolinitic clay minerals. With time, deltaic conditions
became stabilized with only the occasional brief
inundation by the sea.

As the process of leaching and base removal continued, the
pH fell and at a level of 3.5 to 4.0 microbiological

activity became very sluggish. Organic material
accumulated, later becoming coal. These areas were often
slowly subsiding basins so that acid swampy conditions
developed in which dead organic material only partially
decomposed.

Several times the whole delta area and coal swamp became
submerged below the sea again so that the sequence of
limestone, shale, sandstone and coal was repeated. This
sequence is called the Yoredale cyclothem. If submergence
was not sufficient to allow the limestone to form as with
the near shore sequence, the Millstone Grit cyclothem
(shale—sandstone—coal) evolved. The complete system of
deposition, from near shore to open sea is shown in Fig. 8.2.

The Yoredale cyclothem was first described explicitly by
Miller (1887) and latterly in an idealised but much more
detailed form by Johnson (1959).

The full Yoredale cyclothem according to Johnson (1959)
is:

COAL

(x) Coal, ganister or seatearth, and some of: sandstone,
flags, shales, limestones or marine shales

SANDSTONE

(ix) Sandstone, often current bedded

(viii) Thin bedded sandstones, flags, shales and siltstones

SHALE

(vii) Relatively unfossiliferous ferruginous shale

(vi) Dark pyritic shale

(v) Fossiliferous calcareous shale

(iv) Dark blue fragmental limestone, marl bands and
partings

LIMESTONE

(iii) Light grey bioclastic limestone

(ii) Dark blue-grey muddy limestone

(i) Fossiliferous marine shale and sandy shale

COAL BELT CYCLOTHEMS

— YOREDALE FACIES—

OPEN SEA FACIES

zone 4
limestone

zone 3
shale and limestone

zone 2
coal, sandstone,
shale and limestone

NEARSHORE FACIES

zone 1
coal,sandstone and shale

hinterland

Fig. 8.2 Schematic section indicating some of the features of variation of sedimentary succession in a single Yoredale

Cyclothem. (After Johnson, 1961; Westoll, 1968.)

71

A wide range of post-Carboniferous rocks will be excavated
during the sinking of a mine shaft, but even during the
subsequent mining solely within the Coal Measures, a

wide variety of rocks will be encountered. Though any
material within the Yordalian cyclothem may be included,
most colliery waste will come from strata neighbouring the
coal seams. As Johnson showed, these neighbouring seams
are heterogeneous consisting of “seatearth, and some of:
sandstone, flags, shales, limestones or marine shales.”

8.4.2 Mineralogy of pit heap materials

The majority of pit heap material is composed of the
following minerals:

aluminosilicates such as illite,
muscovite, Kaolinite

Clay minerals

Muscovite

Quartz Si0>

Felspar e.g. orthoclase KAISi30g
Hematite, magnetite Fe703, Fe304

Goethite Fe(OQH)O

Iron pyrite FeS>

Other minerals in small amounts have been identified,
e.g:

Tourmaline borosilicate of aluminium
containing alkali metals or iron and
magnesium

Siderite FeCO3

Jarosite KFe3(SO4)>(OH)¢

(a) The clay minerals The principal clay minerals in pit
heap materials are of kaolinitic and micaceous types. A
fireclay seatearth will contain a high percentage of
kaolinite but shale deposited in marine conditions will
contain illite and muscovite as well as kaolinite.

(b) The formation of iron sulphides A common feature

in the formation of Coal Measure shales was the association
of high levels of organic material with the fine grained
mineral sediments. Though the marine fauna would have
made some contribution, probably most of the organic
material came from the lush vegetation in the neighbouring
delta region.

With the onset of bacterial decay of the organic component
in the waterlogged or submerged muddy sediments, a highly
reducing environment was established. Under these
conditions bacteria such as Desulphovibrio desulphuricans
(Kuznetsov et al., 1963) reduced sulphate ions from the

sea water in contact with the sediment (Kaplan er al., 1963).

In essence the following reaction took place:
SOz~ + 2CH,0 —- H»S_ +
seaw ater organic matter

2HCOZ

Either the bicarbonate ions were lost from the sediment or
they partially decomposed and precipitated out as
carbonates. The sulphide ions reacted with a variety

of iron minerals initially forming the extremely insoluble
iron sulphide, mackinawite, FeS (Berner, 1967a).

At pH 6-9 2HFeOz + 3H7S — 2FeS + S0+ 4H50
goethite mackinawite

72

Mackinawite would combine with further quantities of
sulphur forming greigite Fe3S4 and eventually pyrite
(Berner, 1967b)

FeS = 8 s0 =: Fe 384
mackinawite greigite

Fe3S4 + 280 -, 3FeS,

greigite pyrite

Where there was insufficient sulphur to complete the
conversion to pyrite, sulphides of composition intermediate
between FeS and FeS> would have exisged in the sediment
but would have slowly formed pyrite and another iron
mineral (Goldschmit, 1958).

Fe3S4 = 2FeS + FeS5

greigite mackinawite pyrite
followed by

2FeS + 1CO3 — FeCO3 + FeSz 22
mackinawite siderite pyrite

Because of their instability it is most unlikely that either
mackinawite or greigite could now be found in black
shale.

Pyrite is therefore by far the most common iron sulphide
found in Coal Measure shales, but marcasite FeSj may
also have been formed. In addition there is some

evidence of the presence of pyrrhotite FeS in these shales.

(c) The weathering of iron sulphides The weathering of
iron sulphides may proceed along any of several
multistage- pathways. According to Mapstone (1954) the
following products can be formed: ferrous mono-sulphide,
ferrous sulphate, sulphuric acid, sulphur dioxide, hydrogen
sulphide and elemental sulphur. Ferrous mono-sulphide is
unstable and is not likely to persist as such in a pit heap.
Ferrous sulphate is found in the ground water of a shale
tip and also as efflorescences on the weathered veins of
iron pyrites. The very low pH of many shales indicates the
presence of sulphuric acid. The gases sulphur dioxide and
hydrogen sulphide are given off in readily identifiable
quantities when a pit heap burns, and in the same
circumstances crystalline elemental sulphur is frequently
found condensed on the relatively cool shale surface.

Temple and Delchamps (1953) pointed to the role of
autotrophic bacteria in the weathering of sulphides.
Thiobacillus ferrooxidans oxidises ferrous sulphate to

ferric sulphate while Thiobacillus thiooxidans oxidises
sulphur to sulphuric acid. Russian workers.(Kuznetsov et al.,
1963) have reviewed the physiology and ecology of these
and other autotrophic bacteria.

Ferric sulphate hydrolyses rapidly and if allowed to go to
completion, forms a ferric hydroxide gel. If hydrolysis
is incomplete basic ferric sulphate results (van Beers, 1962).

The ferric hydroxide gel is not stable as such and
crystallises out at geothite or lepidocrocite which forms
crusts or stains on shale fragments. Sometimes in an acid,
potash rich environment, jarosite, KFe3(SO4)9(OH)¢, is
formed as a lemon yellow powder or stain found within
cleavages, or on the surface of shale fragments. Possibly
natrojarosite NaFe3(SO 4)(OH)6¢, and alunite

K A1l3(SO4)(OH)¢could also be formed.

The weathering of iron sulphides gives rise to two problems
of importance in plant/soil relationships; firstly the

development of extreme acidity and secondly the
fixation of phosphate.

The abundance of hydrogen ions in the shale proto-soil
causes a high proportion of hydrogen on the exchange
site; this leads to the very rapid loss of bases when the
material is leached, followed by the breakdown of illitic
clay minerals. Muscovite, chlorite and kaolinite are more
stable in acid conditions. As the illitic material disintegrates
large quantities of aluminium are liberated into the soil
solution. At these low pH values manganese is also

released from manganese containing minerals. Plant growth
is inhibited on these very acid shale soils largely as a

result of the toxic levels of manganese and aluminium.

Though many shale soils are acidic, fortunately not all are.
Fig. 8.3 shows the percentage frequency of samples falling
within pH units from 2.0 to 9.0. Taking pH 6.5 as ideal,
just over 25% of the samples were above that value.

Hall (1957) reported that shales are neutral or alkaline
when tipped but after 100 years become very acid, burned
shales showing an accelerated trend. This is a very
simplified view as some shales are already acid when tipped
(Moffatt, 1966) whereas other shales have relatively stable
high pH values. A burned shale, exposed to weathering

for twenty years at DonningtonColliery, Northumberland,
was found to contain free carbonate and to have a pH of
8.6. This variability of soil reaction is to be expected from
geochemical considerations.

The physiological aspects of plant survival on acid soils
are reviewed by Jackson (1967). Liming usually corrects
the direct and indirect effects of acidity or at least makes
their solution much easier.

The other main problem arising from the weathering of
iron sulphides is phosphate fixation. When phosphorus is
added to a shale much of the nutrient reacts with the iron
to form a highly insoluble precipitate, the solubility
product of ferric phosphate being pK.,33—35 (Chang and
Jackson, 1957). In acid soils the greatly increased

amounts of labile aluminium also fix phosphate, aluminium
phosphate having a solubility product of PKyp28—32
(Chang and Jackson, 1957). Reviews of phosphate fixation
are given by Russell (1961) and Kardos (1964).

Preliminary results with shales indicate that phosphate
requirement is closely correlated with pH, low pH values
being associated with high phosphate requirements.

"te FREQUENCY

Fig. 8.3 The % frequency of pH values of shale. (The

information was based on 168 measurements made on
shale from 44 sites which were mostly in the northern
coalfields.)

Theoretically, raising the pH should increase the
availability of phosphate in iron and aluminium compounds
but in practice an increase of 10% or less is achieved.
Phosphate added after the pH of the shale is raised is

fixed to a smaller extent so it is important that a site is

first limed, then fertilized and not vice versa.

8.4.3 Salinity in shales

Salinity in the coal forming delta and the prodelta was likely
to have been heterogeneous. Some material will have been
leached with fresh water, while depressions in the delta
were likely to be inundated periodically with sea water
leaving rich deposits of salt after evaporation.

In an intermediate position would be vast areas of poorly
drained sediments frequently inundated with brackish
water giving the resulting shale a substantial salt content.
As well as the sediments formed in deltaic conditions, there
were considerable quantities of fine textured submarine
deposits whose present salt content must reflect their
environment during formation.

The salts contained in shales will be those left by sea water
plus other salts originating from processes occurring at the
time of deposition or later. The major salts formed during
evaporation are sodium chloride, potassium chloride,
magnesium chloride, magnesium sulphate and calcium
sulphate. Whittig and Janitsky (1963) outlined a system
operating in deltaic and estuarine environments whereby
calcium, magnesium and sodium carbonates are formed
together with iron sulphides. It is likely that this system
would also operate in coal forming environments.

As soon as a fragment of a saline shale is exposed to
weathering the soluble salts are rapidly released. High
levels of salts in the soil solution adversely affect the
vegetation in the following ways:

(a) Salinity increases the minimum soil moisture
content at which plants are able to extract sufficient
moisture (Wadleigh and Ayers, 1945).

(b) High sodium levels cause dispersion of the soil and
a most difficult physical soil condition develops.

(c) Certain ions precipitate other specific ions and
reduce their availability in the soil, e.g. high
levels of bicarbonate precipitate calcium and
magnesium ions as carbonates to such an extent
that there is an unfavourable balance of sodium and
potassium in the soil solution. Phosphate can be
precipitated by calcium, iron or aluminium,
depending on pH, leading to phosphate deficiency
symptoms.

(d) High levels of one cation cause an imbalance in the
uptake of other cations by ionic com petition e.g.
high levels of potassium suppress the uptake of
magnesium.

(e) Direct injury to vegetation follows from excess of
certain ions, e.g. boron at 2 ppm in the soil solution
will inhibit plant growth (Reeve and Fireman, 1967).

Soil salinity can be estimated in a number of ways, but the
normal method is by measuring the electrical conductivity
of the saturated moisture extract (see section 8.5.6). The
units of measurement are milli mhos per centimetre and an
interpretative scale is given (U.S.S.S.S., 1954).

Salinity problems have been encountered on a number of
reclamation sites in the Northumberland and Durham

73

coalfield. Where a saline pit heap is regraded the new
surface will have come from well inside the pit heap where
the shale has the highest salinity.

At the Roddymoor site, Co.Durham , electrical conductivity
values for the saturated moisture extract of surface

samples immediately after regrading ranged from 1 to 25
m.mho/cm. On much of the site, test germination of

S24 ryegrass was as low as 5%.

Salinity values at Roddymoor immediately after regrading

Salinity level m.mho/cm % of total shale surface
25°C

non saline o-2 4

very slightly saline 2—4 13

moderately saline 4-8 35

strongly saline 8— 16 36

very strongly saline 16+ 12

In such a situation a period of leaching by rainwater is
essential before sowing is undertaken. In the summer
months evaporation from the soil often exceeds the
rainfall so there is a net upward movement of salts which
may be left as efflorescences at the surface. The only
times of the year when there will be effective leaching
are late autumn, winter and early spring.

Fig. 8.4 shows the variation in salinity for three areas of

the Roddymoor site from early March 1968 (when regrading
was completed) to November 1968. Coupled with this is a
histogram for net water movement based on rainfall

figures for the City of Durham and evapotranspiration
figures for N.W. Durham. The estimated net moisture
movement is not entirely accurate as the rainfall figures
were measured 13.5 km (8.5 miles) from the site and at
150m (SOOft) lower altitude. Also the evapotranspiration
data assumes a vegetation cover. The data does not take into

Electrical conductivity
saturated moisture
extract mmno

Net moisture deficit

Net percolation

z
3
E
=
2

Earth mo

Bu FEB MAR APR may «(JUNE JULY AUG SEPT OCT NOV

——— South facing shallow shale
—&—4 South facing deep shale
———-_ North facing deep shale

Fig. 8.4 Variation of salinity with water movement at
Roddymoor. March — November 1968.

74

account any difference between the microclimate and the
average for the district on which the figures are based. For
each month Fig. 8.4 probably underestimates net
percolation by about 18mm and overestimates the net
moisture deficit by the same amount.

The figure indicates the strong link between net percolation
and a lowering of salinity and vice versa. When the
electrical conductivity values fell to 4 m.mho/cm sowing
was undertaken.

When a saline tip has been regraded it is important for the
material to be thoroughly ripped to depth especially on
the ‘fill’ areas. An effective drainage system should be
employed to encourage efficient leaching and removal of
saline ground water especially along potential spring lines.

8.4.4 General nutrient status of colliery shales

(a) Nitrogen To a large extent nitrogen governs the level
of plant growth. Shales can supply little or no
nitrogen so that all requirements of non nitrogen-
fixing species of vegetation must be met by additions
of fertiliser. Most plant residues rotting down on the
soil surface use up nitrogen and unless plenty is
available for both residues and living plants, the
vegetation will suffer from nitrogen starvation. In the
initial stage of reclamation high levels of this nutrient
should be applied to allow both adequate crop
growth and rapid humification of dead plant
material. High levels of nitrogen tend to kill out the
clover content of a sward, largely by shading out the
shorter species. Frequent cutting of the sward helps to
preserve the clover and also encourages greater
tillering of the grass.

Nitrogen should be split over several applications, but
given at a low level at the end of the growing season
as it reduces the potential winter hardiness of the
crop.

(b) Phosphorus There is little or no available phosphorus
in colliery shales, and much of the added phosphorus
is fixed in an unavailable form. Phosphate should be
applied at a rate that allows for both fixation and
plant requirements. Data from a limited number of
analyses indicate that phosphate requirements can be
as high as 2500 units P>Os5/acre for the<2mm
material (this figure, worked out on the < 2mm fraction,
should be proportionally decreased to allow for the
coarser, less reactive component of the total sample).

A deficiency of phosphate leads to stunted growth
and loss of vigour. Ryegrass grown on phosphate
deficient shale takes on a growth habit similar to
that of Festuca ovina.

The effect of phosphate deficiency may be seen by
comparing PgKg with P) Kg and PoK, with P) Ky
in Fig. 8.5. Not only is the aerial growth stunted
but the root systems are restricted, this being
significant because shale has a poor water holding
capacity and roots must penetrate to depth to
obtain sufficient moisture. Rooting will be
confined largely to the shale which has received

an application of phosphate so depth of application
is important. Deep cultivation after phosphate is
applied is important but it is even better on ‘fill’
areas to have several broadcast applications during
placement of the last 18 inches of shale.

PK factorial trial NFS/2. Black shale; first harvest PK factorial trial BRU. Red shale; first harvest

me,
coms
Po Ki rnK =
eae C |
PK factorial trial BRS. Red shale; first harvest PK factorial trial BBS. Black shale; first harvest

Fig. 8.5 Response of S24 Ryegrass to potash and phosphate fertilisers in a factorial trial on black and red (burned) colliery
shale soils.

Po no phosphate applied

P1 phosphate applied (150 units P20¢/acre)

Ko no potash applied

Ky potash applied (100 units K20/acre)

All soils limed to pH 6.5 and given optimum nitrogen.

On acid sites either rock phosphate or basic slag may should be split over two or more applications. Total
be applied though they are only slowly soluble and annual applications should not exceed 120 units
may not supply phosphate at a sufficient rate for K>50/acre

fast growing vegetation. On neutral sites the efficiency
of these cheaper fertilisers is greatly reduced and
superphosphate should be used (Cooke, 1967)

(d) Calcium Calcium is unlikely to be in short supply on
neutral or alkaline shales but might be deficient on
very acid material. As liming would be undertaken

(c) Potassium Together with nitrogen and phosphorus, anyway, a calcium deficiency would be rectified
potash completes the group of major nutrients most
often deficient in soils. Greenhouse trials with shale
soils have indicated that there is seldom any great
lack of available potash and additions occasionally
depress plant grow th. Comparison of PoKo with
PoK}, Py Kp with P; Ky indicate the effect of added
potash on a sward (Fig 8.5)

(e) Magnesium Extensive factorial greenhouse tnals with
magnesium and potassium showed no response to
magnesium even when high levels of potash were
applied. It is possible that a strongly weathered acid
shale limed with a pure calcium limestone and given
high levels of potash and ammonium nitrogen might

show magnesium deficiency. The use of a limestone

Recommendations of potassic fertiliser for shales ontaining a little magnesium would avoid this
are based on potassium removed by crops. For situation

example, a hay crop of 35 cwt/acre dry matter

containing 2% K>5,O removes 88 units K5O/acre (f) The trace elements As far as is known, there are n
This figure represents the approximate level of published analyses of the trace elements in colliery
potash required where one hay crop per year is shales of North East England. Namurian shales
removed. The total amount of potash to be applied similar to those in the Northumberland/Durham

“i

Ww

coalfield outcrop in other parts of the British

Isles and have been examined in places. High levels

of molybdenum and selenium have been reported in
the Namurian shales of Co. Limerick, Eire (Webb and
Atkinson, 1965; Thornton ef al, 1966). Similar results
have been found with the Namurian shales outcropping
in the Southern Pennine area (Webb et al., 1968).

Samples of a grass/clover sward grown on colliery
shale at the Roddymoor (Co. Durham) site have been
analysed* for the following elements; cobalt,

nickel, molybdenum, iron, lead, tin, zinc, vanadium,
titanium, chromium, copper, manganese, barium,
strontium, aluminium, boron and silicon. None of
these elements was present in the herbage at levels
likely to cause either toxicity or deficiency symptoms
in farm animals (Scott, 1970).

The reclamation of extremely acid shales necessitates
the use of high levels of lime and phosphate. It is
possible for these treatments to induce deficiencies of
various trace elements which, though present in the
shale, become unavailable to plants. An induced
deficiency of iron has been encountered under these
circumstances and it seems possible that deficiencies
of zinc and copper could also occur.

Sewage sludge, which is frequently advocated as
bulky organic fertilizer, sometimes contains toxic
levels of zinc, especially where the sludge comes
from highly industnalised areas.

8.5 The assessment of soils and shales and the
treatment necessary for their reclamation

8.5.1 Sampling methods for soils and shales

The most skilful laboratory analysis is of little value in
advisory work unless the conclusions drawn from the
operation can be applied to a volume of soil in the field.
This step from laboratory data to field recommendations
is possible only when the sample analysed accurately
represents the field soil or has a known and measured
bias from it. Jackson (1958) outlines the theory and
practice of soil sampling and the normal procedure for
handling samples.

The procedure for sampling is as follows: a number of
samples are taken from the volume of soil in the

field (field subsamples ), and these are bulked together
and thoroughly mixed (bulked samples), laboratory
analyses are performed on appropmiately sized
subsamples (lab. subsamples) withdrawn from the bulked
sample.

There are three possible stages where errors can be
introduced making a laboratory figure misrepresentative.

(a) Misrepresentation of the field by poor field sampling

(b) Misrepresentation of the bulked field sample by poor
subsampling

(c) Variation of analytical figures for the laboratory
subsample

Any errors involved in (b) and (c) are usually relatively
small com pared with (a) so that very careful attention

* Analyses kindly carried out by Dr R.O. Scott,
Macaulay Institute for Soil Research

76

should be given to obtaining representative field samples.
Each bulk sample should represent one volume of soil
thought to behomogeneousfor the purposes of the
intended analyses. Sufficient core samples should be taken,
and from properly distributed locations over the whole

soil volume 1.e. at random or on a strict grid system.

Reed and Rigney (1947) suggest that normally 20 to 30
subsamples from one area, when bulked together, reduce
the field sampling error to the same order as that of (b) and
(c). Each core of soil should have uniform cross-sectional
dimensions.

The bulked field sample is usually air dried before analyses
are undertaken though some determinations such as pH
and available potash are best done on the moist sample.
Drying should be slow and at a temperature not

exceeding 35°C. Once the soil is dry enough to handle
conveniently further drying is unnecessary unless long
term storage is envisaged.

Atterberg (1912) proposed a system for classifying soil
texture which is accepted by the International Society of
Soil Science.

Coarse sand 2.0 —0.2 mmdia.
Fine sand 0.2 —0.02 mm dia.
Silt 0.02 — 0.002 mm dia.
Clay below 0.002 mm dia.

Soil particles exceeding 2.0 mm diameter are classed as
gravel or stones according to size (British Soil Survey Staff,
1960; U.S. Soil Survey Staff, 1951) and being comparatively
inert can be regarded as diluents. After drying the bulked
field sample, the material is sieved through a mesh having

2 mm apertures. The finer fraction is retained for analysis
and its proportion of the total sample is calculated. With
soils, gentle grinding may be necessary to break up soil
aggregates which would otherwise be retained in the

stone fractions.

The bulked and sieved field sample should weigh several
kilos but individual analyses are usually on 5 to 25 g
subsamples. A system of quartering ensures that laboratory
subsamples are representative of the bulked sample, see Fig.
8.6.

AIR ORY SAMPLE

After thorough mixing, the
sample is spread ot over
a clean smooth surface

Pe

os

then quartered

i ——

Two opposite quadrants
is ore mixed together

By ne
i '
quartering is repeated etc. 3 Ps
a
a =
a ; 4

The sequence is repeated until the >
somple is sufficiently recuced in size i

Fig. 8.6 A system of quartering for reduction in sample size.

The diagnosis and treatment of shale material must be
based on the detailed inspection of all materials on each
site. Coal bearing strata vary considerably along their
length as well as vertically up the geological column
(Hemingway, 1968), so that generalisations cannot be
made even for one particular stratum of shale. Varying
lengths of weathering on inherently variable material
makes each colliery tip individual, requiring individual
assessment and treatment.

8.5.2 Measurement of pH applicable to soils and
shales

(a) Special apparatus and chemicals Laboratory pH meter
with combination glass-reference electrode and
temperature compensating probe e.g. Pye universal pH
meter and millivoltmeter Gallenkamp Cat. no. 11067.

Buffer solution tablets for pH 4.0, 7.0 and 9.15.

(b) Procedure Although there are many procedures for
determining pH the following method is in common use
and is suggested. 10 g of air dry soil (<2mm material)
is placed in a SO ml beaker and 25 ml of distilled
water added. The suspension is periodically stirred for
half an hour and the pH of the agitated suspension is
then measured. The figure obtained must be labelled as
for a 1:2:5 aqueous suspension.

8.5.3 Lime requirement

Modified from Shoemaker et al. (1961). Applicable to
soils and shales.

(a) Chemicals
Paranitrophenol
Triethanolamine
Potassium chromate
Calcium acetate
Calcium choloride dihydrate
Sodium hydroxide solution 1.0 N approx.
Hydrochloric acid 1.0 N approx.

(b) Procedure

(i) Preparation of the buffer 1.8 g paranitrophenol,
2.5 ml triethanolamine, 3.0 g potassium chromate,
2.0 g calcium acetate, and 53.1 g calcium chloride
dihydrate are placed in approximately 800 ml
distilled water contained in a 1000 ml beaker, and
stirred until dissolved. The solution is made up to about
950 ml with distilled water and the pH adjusted to
exactly 7.5 with sodium hydroxide solution or
hydrochloric acid as appropriate. The buffer solution is
transferred to a 1000 ml volumetric flask and made up
to the mark with distilled water.

(ii) Measurement of lime requirement 10.0 g air dry soil
(<2mm fraction) is placed in a 100 ml beaker and
25 mil distilled water added, the suspension is stirred
periodically for half an hour when the pH of the
agitated solution is measured. If the pH is below 6.0
a lime requirement test is used, the procedure being
as follows.

The soil suspension is transferred to a shaking bottle and
15.0 ml of the buffer solution is added by pipette. The
bottle is stoppered and shaken overnight (17 hours at
room temperature) and the pH is measured. By
referring the soil/ouffer pH to the standard curve in

Fig. 8.7 the appropriate lime requirement can be
estimated. If the soil/buffer pH is below 5.5 the
procedure should be repeated with half the quantity of
soil.

Values obtained from the standard curve are for the
<2mm fraction and in terms of pure calcium carbonate,
and adjustments should be made for these factors.
Normally not more than six tons per acre of limestone
should be applied at one time.

(iii) Specimen calculation
10.0g< 2mm soil (87.50% oven dry matter) used in test
<2mm fraction constitutes 95.3% total sample
pH of soil/buffer suspension = 5.9
Limestone to be applied has a calcium carbonate
equivalence of 91%

From the standard curve, lime requirement =
= 2.8 T/A pure CaCO 3

adjusted for true weight of sample =
= 2.8 x 100 T/A pure CaCO3
87.5

adjusted for % >2mm material, regarded as a diluent =
= 2.8 x 100 x 95.3 T/A pure CaCO3
87.5 100

Lime requirement = 3.4 tons/acre ground limestone

8.5.4 The determination of available phosphate and
potassium

The determination of available potassium is appropriate
for both soils and shales but the available phosphate
technique can be applied only to the soils. Phosphate and
potassium are extracted by shaking the soil with 0.5 N
ammonium acetate in 0.5 N acetic acid solution for half an
hour. Phosphate in the extract is determined using the
molybdate blue method of Murphy and Riley (1962),

and potassium by flame photometry.

LIME
REQUIREMENT
5

pH of soil/buffer suspension vs. lime requirement

73 ? 65 e $s s ae

oH OF SOIL /BUFFER SUSPENSION

Fig. 8.7 Lime requirement of pH values of soil/buffer
suspension,

77

Extraction of available nutrients (N.A.A.S. 1966)
(a) Chemicals, 1

Glacial acetic acid (analar)

Ammonia solution S. gr. 0.880 (analar)
2.0 N sodium hydroxide solution

1.0 N hydrochloric acid
Phenolphthalein indicator solution

Methy! red indicator solution

(b) Procedure, 1
(i) Preparation of extracting agent A 2 N acetic acid

solution is prepared by standardising it against 2.0 N
sodium hydroxide using phenolphthalein as an
indicator. A 1.0 N ammonia solution is prepared by
standardization against 1.0 N hydrochloric acid with
methyl red as an indicator. Equal volumes of the 2.0 N
acetic acid solution and the 1.0 N ammonia solution
are mixed; this is the extracting agent.

(ti) Extraction of available nutrients 10.0 g of air dry<2 mm

fraction material of known oven dry matter content is
transferred to a shaking bottle and 50.0 ml of the
extracting solution is added by pipette. The bottle is
stoppered and shaken briefly, the stopper removed to

release any pressure developed, replaced and shaking
continued for 30 minutes on a reciprocating shaker.
At the end of this period the suspension is filtered
through a 12.5 cm Whatman No. 2 paper in a 6.5 o.d.
funnel. The clear filtrate is used for available
phosphate and potassium determinations.

Determination of phosphate in the extract (Murphy and
Riley, 1962)
(c) Chemicals and equipment, 2

Ammonium molybdate (analar)

Antimony potassium tartrate (analar)
Sulphuric acid, specific gravity 1.84 (analar)
Ascorbic acid

Spectrophotometer e.g. Unicam SP 600

(d) Procedure, 2
Preparation of the standard curve 12 g of ammonium

molybdate is dissolved in 250 ml of distilled water. Both
dissolved reagents are added to 1000 ml of SN sulphuric
acid (148 ml concentrated sulphuric acid per litre),
mixed thoroughly and made up to two litres. This
solution is designated “Reagent A’ and should be stored
in a Pyrex container in a cool dark place.

1.056 g of ascorbic acid is dissolved in 200 ml of
‘Reagent A’. This solution is “Reagent B’. As this
reagent deteriorates rapidly after 24 hours it should be
prepared as and when required.

About 2 g of potassium dihydrogen orthophosphate is
dried in an oven at 110°C for an hour, then allowed to
cool in a desiccator. 1.7576 g of this salt is placed ina
200 ml volumetric flask and dissolved in distilled
water. 5 ml of 2N hydrochloric acid is added and the
solution made to volume with distilled water. One drop
of toluene is added and the solution which contains
2000 ppm P and 2525 ppm K is then stable for up to
six months. This solution is designated ‘Solution C’.

10 ml of ‘Solution C’ is diluted to 2 litres with distilled
water. 0.0, 1.0, 2.0, 3.0, 4.0, 5.0 ml of this solution are
placed in six 50 ml volumetric flasks and diluted to about
40 ml with distilled water. 8 ml of “Reagent B’ is added

78

to each flask, made to volume with distilled water and
mixed thoroughly. The flasks contain 0.0, 0.2, 0.4,
0.6, 0.8, 1.0 ppm P solutions respectively. After
allawing ten minutes for full colour development the
optical density of each solution is read in a 1 cm cell
using light of 8801 m wavelength. The colour is stable
for at least one day. Distilled water is used in the blank
cell of the spectrophotometer and optical density of the
zero phosphorus concentration solution is deducted
from all other density readings. A standard graph of
corrected density readings is drawn against phosphorus
concentration.

Measurement of phosphorus in the extract

(e) Procedure, 3
An appropriate volume of the soil extract is placed in a
50 ml volumetric flask and diluted to about 40 ml with
distilled water, 8 ml of ‘Reagent B’ is added. The
solution is made to volume with distilled water and the
optical density determined in a 1 cm cell at 880pm.
after at least 10 minutes. The standard graph is used to
calculate the phosphorus content of the 50 ml aliquot.

This procedure is repeated for a similar aliquot of the
original extracting solution and any phosphorus detected
is deducted from the phosphorus level in the soil
extract.

(f) Specimen calculation

Optical density of phosphorus solution 0.311
Optical density of unused extracting solution 0.002
Volume soil extract made up to 50 ml 2.5 ml
Total volume of extract 50.0 ml
Weight soil used 10.0 g

Corrected optical density = 0.311 — 0.002 = 0.309

From standard curve optical density of 0.309 = 0.2 ppm P
Weight of phosphorus in total soil extract = 0.2 X 50 X 50
2.5
Available P as pgP/g soil =_200= 20
; 10.0

Available phosphorus (P) = 20 ppm

(g) Interpretation of results Interpretation of results will
vary from region to region; the following system has been
found satisfactory for N.E. England (Hunter, 1967).

Available P ppm Category Phosphorus application

required
O-— 5 low 2 x standard P application
6—12 medium 1 x standard P application
13 — 20 good
above 20 high little response expected

Determination of potassium in the extract

(h) Chemicals and equipment, 4
2N Hydrochloric acid
Potassium dihydrogen orthophosphate (analar)
Toluene

Flame analyser e.g. Gallenkamp Cat. No. FH-500
Air compressor e.g. Gallenkamp Cat. No. AF-510

(i) Procedure, 4

(i) Preparation of a standard curve 100 ml of ‘Solution C’
(see prep. of standard curve — available phosphorus)
is diluted to 252.5 ml. This.solution now contains
1000 ppm K. 0, 2.0, 4.0, 6.0, 8.0, 10.0 ml of this
solution is diluted to 100 ml aliquots, which will
contain 0, 20, 40, 60, 80, 100 ppm K respectively. A
series of flame photometer readings for these
solutions are obtained and plotted on a graph of
photometer reading versus concentration of
potassium.

(ti) Measurement of potassium The original extracting
reagent is tested for potassium and any found is
deducted from levels in the soil extracts. The soil
extract is tested for potassium and by relating the
photometer reading to the standard curve the
potassium content of the soil extract may be
calculated.

(j) Specimen calculation
Weight soil = 10.0 g
oven dry matter content = 96.3%
<2 mm fraction = 88.1% total fraction
Photometer reading 40.5

From standard curve the photometer reading of 40.5
corresponds to 23 ppm K therefore the 50 ml extract
contained 1150 ug K
Weight soil = 10.0 X 96.3 = 9.63 g
100
Available K = 1150ugK/9.63 g sample
= 119.4ugK/g (or ppm)

Available K for total fraction = 119.4 x 88.1

100
(Where >2 mm material regarded as a diluent)

= 105.2 ppm

(k) Interpretation of results Interpretation of results will
vary from region to region. The following system
has been found satisfactory for North East England
(Hunter, 1967).

Available K ppm Category K application required

0-35 low 2 x standard K application
36 — 83 medium 1x standard K application
84 — 104 good 1 x standard K application
above 104 high No K response

8.5.5 Phosphate requirement of shales (Modified
from Ozanne and Shaw, 1968; Murphy and
Riley, 1962)

As there is little or no available phosphate in colliery shales,
extraction techniques are unsuitable. A more appropriate
method for assessing phosphate requirement is the one
Ozanne and Shaw (1968) advocated. It measures how much
phosphate must be applied to the shale to increase the
available phosphate to an acceptable level.

(a) Chemicals
Calcium chloride (analar)
Calcium tetrahydrogen diorthophosphate
Sulphuric acid specific gravity 1.84 (analar)
Ascorbic acid

Ammonium molybdate (analar)

Antimony potassium tartrate (analar)

(b) Procedure
(i) Standard curve (Phosphate measurement by the method

of Murphy and Riley, 1962) 12 g of ammonium
molybdate is dissolved in 250 ml of distilled water.
0.2908 g of antimony potassium tartrate is dissolved in
100 mi of distilled water. Both dissolved reagents are
added to 1000 ml of SN sulphuric acid (148 ml
concentrated sulphuric acid per litre) mixed thoroughly
and made to 2 litres. This solution is ‘Reagent A’ and
should be stored in a Pyrex container in a dark, cool
place. 1.056 g of ascorbic acid is dissolved in 200 ml of
‘Reagent A’ mixed, and is designated ‘Reagent B’. This
reagent should be freshly prepared when required as it
is unstable after 24 hours

1.0170 g of dried (80°C) analar calcium

tetrahydrogen diorthophosphate is dissolved in distilled
water and made to 500 ml; 10.0 ml of this solution are
transferred to a litre volumetric flask and diluted to
volume with distilled water. This solution contains 5 ppm
P. 0.0, 2.0, 4.0, 6.0, 8.0, 10.0 ml of the solution are
placed in six 50 ml volumetric flasks respectively,
distilled water added to make up to the mark.

The six flasks contain P at 0.0, 0.2, 0.4, 0.6, 0.8, 1.0

ppm concentrations respectively. 8 ml of ‘Reagent B’ is
placed in each of the six 50 ml flasks and made up to

the mark with the 0.0, 0.2, 0.4, 0.6, 0.8, 1.0 ppm P
solutions in turn. After allowing 10 minutes for colour
development the optical density of the solutions is

read ina 1 cm cell at a wavelength of 880um. A graph

is plotted optical density against phosphorus concentration
(i.e. corresponding to 0, 0.2, 0.4, 0.6, 0.8, 1.0 ppm P).

(ti) Measurement of phosphate requirement Four or five

portions of the air dry<2 mm fraction material are
weighed out,each sample containing exactly 6.0 g

oven dry material, The samples are transferred to 125 ml
shaking bottles and 60.0 ml of the Ca(HPO4)5.H30

in 0.01 N CaCl solution added. The phosphate
contents of the 60.0 ml aliquots are chosen so that

after equilibrium with the shales they cover the range
0.1 — 1.0 ppm P in solution. One drop of toluene is
added to each bottle which is then stoppered and shaken
for two half hour periods each day for twenty days.

The suspensions are then filtered through a Whatman
No. 2 paper into a SO ml volumetric flask which contains
8 ml of ‘Reagent B’. Enough filtrate is added to bring
the volume up to the mark. The optical density is
measured as detailed above and by reference to the
standard curve the phosphorus concentration in the
suspension filtrate is calculated. By subtracting
phosphorus in solution from phosphorus added, the
level of sorbed phosphorus as pgP/g shale can be
estimated. This is done simultaneously for the four

or five suspensions and a graph of phosphorus sorbed
(units P70 5/acre) against phosphorus (ppm) in the
liquid phase is drawn up. | pig P sorbed/g shale is
approximately equivalent to 4.1 units P7Os5 sorbed per
acre to plough depth.

Ozanne and Shaw (1968) showed that for pasture plants,
phosphate required = phosphate sorbed (at the 0.3

ppm P level in solution) with a correlation coefficient
of r= +0.96. Various authors use different phosphate

79

levels in the supernatant liquid; Beckwith (1965) used
0.2 ppm P as a basis for phosphate requirement as

did Fox ef al. (1968). As far as is known, no work has
yet been undertaken with pasture plants growing on
colliery shale in a temperate maritime climate. Until
this data is available Ozanne and Shaw's level of

0.3 ppm is favoured.

Phosphate required =
= phosphate sorbed X %<2mm in total fraction
(0.3 ppm level) 100

8.5.6 Measurement of salinity Applicable to soils
and shales Jackson (1958)

The salt level in shale soils is frequently high enough to
inhibit plant growth. Estimates of salinity are made on the
saturated moisture extracts by measuring the electrical
conductivity of the extracted solutions. The salinity hazard
can be directly interpreted from electrical conductivity
measurements.

(a) Chemicals and special apparatus
Potassium chloride
2, 1lem Hartley 3 section Buchner funnels
11cm Whatman No. 50 filter papers

Filtration tube with side arm (i.d. 30—35mm, length
100—1 10mm)

Specimen tubes (i.d. 25mm, length75mm) and
polythene closures

Conductivity cell e.g. Mullard type E.7591/A
Conductivity bridge

(b) Procedure

(i) Saturated moisture extract
About 100ml of the<2mm fraction air dry material is
placed in a 250 m] Pyrex beaker, and saturated with
deionised water. Saturation moisture content is
defined as the maximum amount of water held in the
puddled soil without free water collecting in a depression
in the soil mass (Scofield, 1932). Preferably the water
should be added in spaced increments so the soil
colloids can imbibe moisture before further water is
added. Should too much water be applied a little extra
soil may be added to soak up the excess. As many
shales contain slowly soluble salts, an equilibrium time
of two hours is required before the soil mass is
transferred to an 11cm Buchner funnel fitted with a
Whatman No. S50 filter paper, see Fig. 8.8. A vacuum is
applied to the system and the clear extract is collected
and used for salinity and pH measurements.

(ii) Measurement of electrical conductivity
Standardisation of the conductivity cell The specific
conductivity at 25°C of a 0.020 N KCI solution is 2.39
m.mho/cm. The conductivity cell is placed in a
0.020 N KCI solution at 25°C and the conductivity,
E.C. is measured. The cell constant, k, is given by
Raed.

E.C.35°¢
Conductivity measurements will vary with temperature
and must be adjusted to the standard temperature of
25°C by using the correction factor f;, see Fig. 8.9
E.C.959¢ =E.C,Xf,
where E.C.75°c is the electrical conductivity at 25°C
E.C., is the measured electrical conductivity at iC
f; is the correction factor see Fig. 8.9.

80

saturated soil

—filter paper

—p to vacuum pump

clear extract

Fig. 8.8 Apparatus used for saturation moisture extraction
and the determination of moisture equivalent.

Measurement of specific conductance of a standard
moisture extract The conductivity cell (cell constant k)
is placed in the saturated extract at temperature ft, and
the conductivity E.C., measured.

Specific conductance = E.C., Xk-X fy.

(c) Interpretation of results

Specific conductance Salinity level Effect on
(25°C) of saturated vegetation
moisture extract
m.mho/cm
O-2 non saline negligible damage
2-4 very slightly yield of very
saline sensitive crops
reduced
4-8 moderately
saline
8-16 strongly yield of many
saline crops restricted
only tolerant
crops yield
satisfactorily
germination
seriously affected
16+ very strongly only few very
saline tolerant crops

yield satisfactorily

(d) Osmotic pressure and salinity
Moisture is available to a plant while at tensions between
0 and approximately 15 atmospheres. At about 15
atmospheres soil moisture tension, plants wilt as they
are not able to extract any more water from the soil
(Baver, 1961). Salts dissolved in solution give the
solution an osmotic pressure which reduces the range of
tensions over which plant roots can extract moisture.

=—— _amanine

The salts likely to be derived from shales e.g. NaySO4,
CaSO4, FeSO4 have similar effects on the osmotic
pressure i.e. approximately 0.3 atm. per m.mho/cm
electrical conductivity (U.S. Salinity Laboratory Staff,
1954). For example if the specific conductance of the
saturated moisture extract is 10.0 m.mho/cm the
maximum moisture tension at which the plant can

still remove water from shale soil will be 12 atmospheres.
At such a reduced moisture content the osmotic pressure
will probably exceed the 3 atmospheres to further reduce
the available moisture range in the material.

8.5.7 Percentage<2mm fraction Application to
shales and stony soils

The %<2mm material in the total sample is an indication of
the degree of weathering and to a large extent the value of
the shale as a growth medium. Extremely low values are
given by materials that can retain neither moisture nor
nutrients. Extremely high values may suggest that
although moisture and nutrient holding capacities are good
there may be tilth problems involving an im permeable
material which roots cannot easily penetrate. Agronomic
values cannot be assigned to %<2mm figures with any
certainty until considerable field work has been completed
but for the initial stages of reclamation values of 40 — 60%
are probably optimal. Fig. 8.10 shows the frequency of
occurrence of values for %<2mm material.

Many analytical figures for the<2mm fraction must be
readjusted when estimates are made for the complete soils.
Procedure

About 8 — 10 kg of air dry material is sieved

through a mesh with 2mm apertures and the % by weight

of the<2mm material in the total sample is calculated.

8.5.8 Moisture equivalent, Bouyoucos (1935)
Applicable to soils and shales

The moisture equivalent of a soil is the % moisture held by
the soil when under a tension of one-third atmosphere; this
moisture content approximates to field capacity. Its
determination can be conveniently linked with the
saturated moisture extraction procedure as used in shale
salinity testing.

ELECTRICAL CONDUCTIVITY CORRECTION
FACTOR VS TEMPERATURE

TEMP °C
30

Le J Bl eo oe
f

(Based on dete from Jackson 1958)

Fig. 8.9 Electrical conductivity correction factor vs.
temperature.

i’ FREQUENCY

le -2mm
MATERIAL IN
TOTAL SAMPLE

Fig. 8.10 Distribution of % 2mm material in 92 samples.
(From 30 sites mostly in N.E. England.)

(a) Procedure

The method is the same as for saturated moisture content
except that the tension applied must be controlled. A
tension of 610mm (25in) of mercury is applied to the
soil in the Buchner funnel for 15 minutes. At the end of
this period a small amount of the moist sample is
removed, weighed and dried in an oven at 105°C for

24 hours. The moisture content of the moist sample is
calculated, this being approximately equal to the moisture
equivalent of the<2mm material. This figure is used as
the basis of the moisture equivalent of the total fraction,
the following adjustments being made:

(i) Areduction to allow for the>2mm fraction which
holds little moisture under tension.

(ii) | An allowance for the moisture held within the
>2mm particles. An average figure of 4.6%
moisture is assumed for wet shale particles.

(iii) An allowance for moisture held between the
<2mm and>2mm particles. An average figure
of 0.069% moisture per %>2mm fraction
in the total sample.

(b) Specimen calculation

Moisture equivalent of <2mm fraction = 13.8 g water
contained by 100 g moist soil
<2mm fraction = 33.4% total fraction

apparent density = 1.10 g/cm}

Moisture content of a saturated shale fragment = 4.6%
— adjustment (ii)

Moisture held between > 2mm and <2mm shale particles
= 0.069% moisture
per % > 2mm material — adjustment (iii)

Reduction for effect of >2mm material
adjustment (i) 13.8 x 33.4 = 4.6% w/w
100

Moisture held in > 2mm material
adjustment (ii) 4.6 x 100—33.4 = 3.1% w/w
100

Moisture held by pore spaces between > 2mm and < 2mm
material

adjustment (iii) 0.069 x (100—33.4)= 4.6% w/w

Moisture equivalent w/w = (i)Hii)+iii)= 12.3% wiw
On v/v basis = 12.3 x 1.10= 13.5%

Moisture equivalent of total soil = 13.5% v/v

81

(c) Interpretation of results

Average values (Pringle, 1969) are sandy soils 15%
loams 30%
clay soils 45%

The figures represent the moisture content, once

gravitational water has moved out of the previously

saturated material and approximate to field capacity.

Values for shales are generally low indicating a

small reserve of water available for plants.

8.6 Summary

The surface of a regraded colliery site usually consists

of freshly exposed shale with or without a thin.covering
of soil. The special problems associated with soil that has
been stored in heaps for any length of time before being
respread are listed in section 8.3. The methods of soil
testing as given in section 8.5 can be used to determine
the nature of treatments necessary to improve the
fertility of the soil.

Section 8.4 deals with the nature and origin of colliery
waste materials. Acidity and its associated effects, phosphate
fixation, salinity and nitrogen deficiency are the major
chemical problems likely to be encountered in reclamation
schemes in Northem coalfields. Methods for both the
diagnosis of these problems and the selection of
ameliorative treatments are given. Low water holding
capacity, excessive stoniness and over compaction of

the shale by heavy earth moving machinery are the physical
problems most frequently occurring during the reclamation
of colliery tips. Methods for identifying these problems are
given in section 8.5.

Volume 2 of this report will include examples of site
investigations together with an evaluation of the success of the
ameliorative treatments used.

Fig. 8.2 is reproduced by courtesy of Dr G.A.L. Johnson
and acknowledgements are given to the publishers of his
article (1961) in which the figure originally appeared —
Geologisch Bureau voor het Mijngebied; to the publishers
Oliver & Boyd Limited and editors Dr Murchison and
Professor Westoll of the article ‘Coal and Coal-Bearing
Strata’ in which the figure also appeared.

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Klassification der Mineralboden Schwedens /nir.

Mitt. Bodenk., Vol. 2, 312—342.

Baver, L.D. (1961) Soil Physics (3rd ed). Wiley, London,
283—285.

Beckwith, R.S. (1965) Sorbed phosphate at standard
supernatant concentration as an estimate of the
phosphate needs of soils. Aust. J. exp. Agric. Anim.
Husb. Vol. 5.52—58.

Berner, R.A. (1967a) Diagenesis of iron sulphide in recent
marine sediments. Estuaries edit. G.H. Lauff. Am.
Assoc. Adv. Sci. Publ. 83, Washington 268—272.

Berner, R.A. (1967b) Thermodynamic stability of
sedimentary iron sulphides. Am. J. Sci. Vol. 265,
773—785.

Bouyoucos, G.J. (1935) A comparison between the suction
method and the centrifuge method for determining
the moisture equivalent of soils. Soil Sci. 40, 165—171.

82

British Soil Survey Staff (1960) Field Handbook. Soil
Survey of Great Britain. Rothamsted. 12.

Chang, S.C. and Jackson, M.L. (1957) Solubility product of
iron phosphate. Soil Sci. Soc. Am. Proc. Vol. 21,
265—268.

Cooke, G.W. (1967) The Control of Soil Fertility.

Crosby Lockwood. London, 125—129.

Fleet, M.L. (1965) Preliminary investigation into the
sorption of boron by clay minerals. Clay Minerals.
Bull., Min. Soc. London. Vol 6, 3—16.

Fox, R.L., Plunkett, D.L. and Whitney , A.S. (1968)
Phosphate requirements of Hawaiian latosols and
residual effects of fertilizer phosphorus. 9th Int.

Congr. Soil Sci. transactions, Adelaide. 2, 301—310.

Goldschmidt, W.M. (1958) Geochemistry. ed. Muir, O.U.P.,
London. 530.

Hall, 1.G. (1957) Ecology of Pit Heaps. J. Ecol. 45, 689-720.

Harder, H. (1961) Einbau von Bor in detritische tonminerale.
Experiments zur Erkarung des Borghaltes toniger

sediments. Geochim et Gosmochim. Acta 21: 284—294.

Hayward, H.E. and Wadleigh, C.H. (1949) Plant growth on
saline and alkali soils. Adv. in Agron., 1, 1—38.

Hemingway, J.E. (1968) Sedimentology of the coal bearing
strata. Coal and Coal Bearing Strata. ed. Murchison
and Westoll, Oliver & Boyd, Edinburgh. 43—69.

Hunter, F. (1967) Private com munication.

Hunter, F. and Currie, J.A. (1956) Structural changes during
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Jackson, M.L. (1958) Soil Chemical Analysis. Constable,
London 10—37.

Jackson, W.A. (1967) Physiological effects of soil acidity
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Monograph No. 12 Am. Soc. Agron., Madison. 43—124.

Johnson, G.A.L. (1959) The carboniferous stratigraphy of
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deltaic sediments in cyclothemic deposits with
particular reference to the Visean and Namurian
of Northern England. C. r. 4 Int. Congr. Strat. Carb.
Heerlen, 1958. 2, 323—330.

Kaplan, I.R., Emery, R.O., and Rittenberg, S.C. (1963)
Distribution and isotopic abundance of sulphur in
recent marine sediments off Southern California.
Geochim et Gosmochim. Acta. 27, 297—331.

Kardos, L.T. (1964) Soil fixation of plant nutrients —
phosphorus. Chemistry of the Soil. ed. Bear,
Reinhold, London. 369—382.

Kuznetsov S.I., lranoy, M.V. and Lyalikova, N.V.

(1963) Introduction to Geological Microbiology.
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New York.

Mapstone, G.E. (1954) The weathering of pyrite. Chem.
and Ind. No. 20, 577—578.

Miller, Jr., H. (1887) The geology of the country around
Otterburn and Elsdon. Mem. geol. Surv: U.K.

Mitchell, R.L. (1964) Trace elements in soils.

Chemistry of the Soil. ed. Bear. Reinhold, London.

Moffatt, D.J. (1966) A field study into the soil forming
factors operating on colliery shales. Rep. 4, Land.
Recl. Res. Proj., Univ. Newcastle upon Tyne. 13.

aay YE

Moore, L.R. (1968) Some sediments closely associated
with coal seams, Coal and Coal Bearing Strata.
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10S5—123.

Murphy, J. and Riley, J.P. (1962) A modified single
solution method for the determination of phosphate
in natural waters. Anal. Chim. Acta. 27, 31—36.

National Agricultural Advisory Service (1966) Determination
of available phosphate and potassium in soil. Rep. of
Analyst Technical Committee, M.A.F.P.

Ozanne, P.G. and Shaw, T.C. (1968) Advantages of the
recently developed phosphate sorption test over the
older extractant methods for soil phosphate. 9th Jnt.
Congr. Soil Sci., transactions, Adelaide, 2, 273— 280.

Pons, L.J. and Zonneveld, I.S. (1965) Soil ripening and soil
classification. Publ. 13. /nt. Inst. Land Recl. and
Impro., Wageningen. 25—27.

Pringle, J. (1969) Private communication.

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of uniform and non uniform appearance and soil
ty pe. J. Am. Soc. Agron., Vol 39, 26—40.

Reeve, R.C. and Fireman, M. (1967) Salt problems in
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Lands, ed. Hagan, Haise and Edmunster. Am.Soc.
Agron., Monograph No. 11. Madison 988—995S.

Russell, E.W . (1961) Soil Conditions and Plant Growth.
9th ed. Longmans Green, London, 481—489.

Scofield, C.S. (1932) Measuring the salinity of irrigation
waters and of soil solutions with the Wheatstone
Bridge. U.S.D.A., Circ. 232.

Scott, R.O. (1970) Private communication.

Shoemaker, H.E., McLean, E.C. and Pratt, P.F. (1961)
Buffer methods for determining lime requirement
of soils with appreciable amounts of extractable
aluminium. Soil Sci. Soc. Am. Proc. Vol 25.
274-277.

Temple, K.L. and Delchamps, E.W. (1953) Autotrophic
bacteria and the formation of acid in bituminous
coal mines. Appl. Microbiol. Vol. 1, no. 5, 255—258.

Thornton, I., Atkinson, W.J., Webb, J.S. and Pool, D.B.R.
(1966) Geochemical reconnaissance and bovine
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Res. Vol 5, 280—283.

United States Soil Salinity Staff (1954) Diagnosis and
Improvement of Saline and Alkali Soils, Handbook
no. 60, U.S.D.A., Washington.

United States Soil Survey Staff (1951) Soil Survey
Manual, Handbook no. 18, U.S.D.A. Washington
205—233.

van Beers, W.F.J. (1962) Acid Sulphate Soils. Bull. 3 Int
Inst. Land Recl. and Imp. Wageningen. 31 pp.

Wadleigh, C.H. and Ayers, C.H. (1945) Growth and
biochemical composition of bean plants as conditioned
by soil moisture tension and salt concentration.

Plant Physiol. Vol. 20, 106—132.

Webb, J.S. and Atkinson, WJ. (1965) Regional geochemical
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in Co. Limerick. Nature Vol 203, 1056—1059.

Webb, J.S., Thornton, I, and Fletcher, K. (1968)
Geochemical reconnaissance and hypocuprosis. Nature
Vol. 217, 1010—1012.

Westoll, T.S. (1968) Sedimentary rhythms in coal bearing
strata. Coal and Coal Bearing S trata ed. Murchison
and Westoll, Oliver & Boyd, Edinburgh. 105—123.

Whittig, L.D. and Janitzky, P. (1963) Mechanisms for the
formation of sodium carbonate in soils. 1. Manifestations
of Biological Conversions. J. Soil Sci. Vol 14. 322—333.

Wills, L.J. (1951) A Paleogeographical Atlas of the British
Isles and Adjacent parts of Europe, Blackie, London.
26-27.

83

Chapter 9 Botanical studies of natural and
planted vegetation on colliery spoil heaps

by J.A. Richardson, B.K. Shenton and R.J. Dicker

9.1 Introduction

In Britain most waste ground which is not contaminated
by toxic material is quickly invaded by plants from the
surrounding countryside. It is well known that some form
of plant cover is often developed in under a decade on such
places as derelict building sites, deserted fields and
footpaths, disused ship-yards, abandoned railroads, brick
fields, quarries and other neglected sites. For pit heaps on
the other hand, it may take seven times as long before the
colonizing vegetation is sufficiently well grown to mask
the ugliness, and this is due mainly to their shape and
height and to the physical and chemical properties of the
surface layers.

From time to time, believing that those who extract the
nation’s coal supplies should not be forced to live
permanently amongst the depressing spoil heaps, men have
tried to retrieve the former beauty of the landscape by
planting spoil heaps with trees and shrubs. Notable success
was achieved in County Durham at Lambton in the

early 1850's, at St. Helens Auckland in the 1920’s, and at
Houghall in the 1930’s where trees were planted on pit
heaps for the sake of amenity. Whyte and Sisam (1949),
Wood and Thirgood (1955), have written reports of work
done elsewhere in Britain and abroad. Three main
advantages accrue from establishing a vegetative cover on a
pit heap. First, there is the improvement of the landscape
by planting with suitable quick growing plants (and fenced
in the first instance, and then, later, perhaps opened as a
natural playground, or given special treatment to make

it into a park). Secondly, there may be the possibility of
some financial return from the growing of trees for timber,
or the sowing of grass for grazing stock. Thirdly, and
possibly the most important advantage for some villages
would be the elimination of a constant source of dust and
grit which, in a dry summer, fill the air and make life
miserable. Nevertheless, the amount of derelict ground on
which vegetation has been established by artificial means
is negligible, and the presence of trees and grasses on
disused spoil heaps is mostly due to natural immigration
from adjacent areas.

A principal aim of investigations into the physiology
and ecology of plants growing in waste places, which
started in Newcastle in 1952 and continued in the
present Project, was to provide information useful to
those people concerned with reclaiming the landscape.
The account which follows summarizes relevant
results.

9.2 Natural vegetation
9.2.1 Coionization

Some of the propagules (fruits, seeds and spores)
produced by mature plants in the neighbourhood are

84

transported by the agency of wind and animals to the
surfaces of spoil heaps. Under favourable conditions they
may germinate and produce adult plants from which a
plant population may develop.

Weathering of the pit heap material

Newly tipped colliery waste often consists of a mixture of
large rocks (SOOmm dia.), which forms the bulk of the
material, together with smaller fragments (2mm dia.) and
very fine material (0.002mm dia.). The breakdown of the
shale by physical and chemical weathering into small
particles has been described by Richardson (1957), who
pointed out that whereas some pit heap surfaces produce a
layer of small hard plate-like shales, on others a surface
layer rich in clay particles is developed. The latter type

of surface tends to puddle when wet, leading to

poor penetration, much run-off and erosion; the former has
no cohesion, penetration of rainfall is high and water
holding capacity is low. Neither of these surfaces
encourages the growth of plants and it was shown that
those heaps which produce an intermediate surface, with a
mixture of small shales and clay particles, are the ones on
which plants spread most rapidly. In the early stages of
weathering when fine particles are easily dispersed by wind
or rainfall, and there is no protection from vegetation, even
the smallest run-off of water will cause loss of soil-forming
particles. Until sufficient particles have accumulated within
a range 2.0mm to 0.002mm it is unlikely that plants will
succeed because it is in the pores (capillaries) that exist
between small soil particles that water available for plant
growth can be held. Greenwood (1963) performed
mechanical analyses on samples of surface material and
found that when the fine fraction, i.e. that which passed
through a 20 B.S. sieve (100mm2 holes), exceeded about
43% of the sample the ‘receptive stage’ had been reached
and colonization occurred; on surfaces with less than 35%
of fine material seeds germinated but the seedlings did not
survive. Brierley (1956) for pit heaps in Derbyshire,
Nottinghamshire and Yorkshire and Pickersgill (1971) in
Durham found that pit heaps were devoid of vegetation
when most of the surface was composed of fine clay
particles. Vegetation appeared on these clay surfaces when
they included sufficient fragments which were retained on
a 20 B.S. sieve. Beneath the surface layer of pit heaps

(say 60 mm) the coarse material may show little change
from the time of tipping except to contain some finer
material carried down from the surface. It was commonly
found (Greenwood, 1963) that while the surface 60 mm
had 55% the next 120 mm had a coarse fraction of 94%.

Clearly these observations made under natural field
conditions are relevant to artificial planting and they were
drawn on when artificial planting procedures were planned
(see section 9.3.1).

Density of incoming fruits and seeds

The natural vegetation of pit heaps (and other derelict
places) is related to the local flora; Richardson (1956)

has described plant communities which can develop on pit
heaps in Durham, e.g. a heather moorland at Haswell

(NZ 375448), a Deschampsia grassland at Springwell

(NZ 287588), a birch woodland at Urpeth (NZ 248555)
and many grass—herb communities elsewhere. There was a
good correlation between the pit heap communities and
the presence of seeding species in the vicinity, their
distance and compass bearing, their numbers and abundance
of seeds, their seed dispersal mechanisms and the weight of
each seed.

The density of incoming seeds is critical because of the
heavy losses which occur amongst those seeds which are
deposited on pit heaps. Brierley (1956) reported that, for

a four week period when seed dispersal was high, about
2,000,000 seeds per ha (800,000 seeds per acre) arrived

on the south west slope of a pit heap. Accepting this as a
typical figure, Greenwood (1963) collected samples of
surface material from a comparable pit heap at Ravensworth
(NZ 260582) and spread them thinly on sterilized soil in
the greenhouse under ideal conditions for germination.

He found that the seeds which germinated represented a
seed density of about 272,000 per ha (110,000 per acre) or
one-seventh of the amount of seeds reaching the heap

from the local countryside. Greenwood further found that
although the greenhouse figure corresponded to about 24
seeds per m2 (20 seeds per yd?) on the pit heap, the plants
were not more frequent than one per m? (one per yd? ) when
the observations were made.

Clearly, there is a high casualty rate amongst the incoming
seeds for which high temperature and drought could be
important causes —see section 9.2.1(b) and (c).

Also important are high winds which lift seeds off the
slopes of pit heaps, and an open texture which allows the
small airborne seeds to be carried to considerable depths in
the heap.

Experiments using Agrostis tenuis and Dactylis glomerata
were carried out in 1961 on north east facing slopes at
Ravensworth which were largely protected from high
winds, high temperature and drought (see Richardson and
Greenwood, 1967). The ground was fairly compact and

the seeds were either spread over the surface of the plots, or
spread lightly, covered with small shales, and then

firmly pressed down. Briefly, the results showed that with a
seed rate of 34.0 g per m2 (1 oz per yd2) the survival was
94% on raked and firm plots and only 10% on unraked
plots. When the seed rate was reduced to 3.0 g per m2
(1/12 oz per yd2), i.e. to the agricultural rate for grass

seed mixtures, the survival was reduced to 14% on raked-
firm plots and to 1% on unraked plots. Greenwood gave
details of the damage caused to surface germinated
seedlings during the first winter and he has compared the
heavy losses with the light losses sustained by seedlings
developed from seeds well established just below the
surface. These results confirmed the earlier findings
(Richardson, 1956) that the ‘receptive stage’ on a pit

heap, i.e. when the immature soil is suitable for the
germination of incoming seeds and for the development of
seedlings, depends on the conjunction of a suitable soil
texture, adequate rainfall, and suitable seed density. Up to a
point it appears that a deficiency in one condition can be
compensated for by an excess in one or both of the others.
For example, a coarse textured soil with a low water

holding capacity will lose seeds carried downwards in
drainage water, and will lose seedlings in summer owing
to drought — see section 9.2.1(c). A high seed rate plus a
high rainfall in any given year could compensate.

The rate of growth is important in the first season; if it is
high the young plants could be sufficiently well rooted to
survive summer drought. In the artificial planting of
grasses and herbs steps must be taken to make the spoil
heaps receptive and to allow for the compensation
mentioned to be applied; reference to how this was done
is made in section 9.3.1.

Factors affecting germination and survival

(a) pH values, toxic substances and essential minerals The
characteristics which develop during the growth of plants
are not determined solely by the factors of inheritance
contained in the protoplasm but are also controlled by the
conditions of the environment, e.g. by temperature,

light intensity, acidity, water content, oxygen content,
etc. For many years it has been known that pH is a factor
almost as important as temperature in many plant processes.
Growth of plants is only maintained between certain
limits of pH; for example, good growth may occur between
pH S and 8, but outside this range, in pronounced acid or
alkaline soils, plant growth is at first retarded and finally
arrested (see Richardson 1964 for details).

On many pit heaps when weathering processes have been
acting for 4 — S years and the receptive stage has been
reached, the soil reaction is neutral or even slightly
alkaline. It appears that in midland and south country
coal fields (Hall, 1957) newly tipped shales tend to have
higher pH values, e.g. pH 8.8 in Somerset and pH 8.7 in
North Staffordshire, than those for northern coalfields,
e.g. 6.9 for Durham and Northumberland (Richardson,
1956). As the plant cover develops from the pioneer
herb—grass stage to a grassland, heather moorland, scrub
or woodland, there is a marked fall in the pH of the
surface material and most surface layers become distinctly
acid after about 80 years. Likely changes of pH in this
period have been reported as follows: pH 7.0 — 3.5
(Richardson, 1956); pH 8.8 — 3.4 (Hall, 1957); pH 8.0 —
3.5 (Greenwood, 1963). Shenton (1967) examined 237
sites and found that naturally occurring and planted
species grew and flourished on pit heaps where the pH
values were between pH 7.0 and 3.0; the distribution of
sites and pH values was as follows:

pH 1046.0) 45) 4.0 3.0
%ofsites O.8 91 25.0 40.6 24.5

The pH varies with depth below the surface as well as
with age. In a 100 year old heap at Birtley (NZ 279554)
on which a mixed deciduous woodland had developed
the values down the profile were as follows:

Depth Organic pH
(mm) content
(%)
Oo— 50 17.6 5.3
50 — 100 6.4 5.8
100 — 200 2.3 6.1
200 — 300 1.5 6.1

Here the pH change (0.8 units) with depth was small
compared with differences of 2.0 units (pH 4.4 — 6.4)
reported elsewhere.

85

The changes in the pH of spoil heap material are influenced
by burning (see below), by erosion and by the type of
vegetation but they also depend very much on the sulphur
content of the shale’s waste coal. Pit heap spoil contains
three forms of sulphur; pyrites, sulphates and organic
pyrites (or marcasites) and in shale large amounts of
sulphur may be present as sulphates or in the pyritic form.
In the north of England the total sulphur content of

waste coal and shales varies from zero to about 12% and
there are wide differences from heap to heap and between
places on the same heap.

During weathering and as a result of moist oxidation of the
sulphur bearing rocks, quantities of free sulphuric acid, iron
sulphates and ferric hydroxide appear in the surface

layers of spoil heaps. Briefly, the presence of these substances

in toxic quantities, together with the low pH values
produces a medium in which growth of plants is often
impossible (for some details of the effect of sulphur on
colonization of eight pit heaps see Richardson, 1957). pH
values in the region of pH 2 are common on pit heaps with
pyrites bearing rocks at the surface and this condition may
persist for over 40 years. Vegetation gains a foothold on
these pit heaps when the toxic products of oxidation are
leached out of the surface layers and cease to accumulate.

When there are large amounts of sulphur (e.g. 6%) in
surface layers which also possess either very high or very
low permeability to water (see: ‘Weathering of the pit heap
material’), conditions exist which may permanently
prevent natural colonization or the success of artificial
planting of trees and grasses. Clearly special problems
attach to reclamation of pit heaps containing pyritiferous
waste, and experiments are in progress to discover how
ameliorating procedures can be practised on a large scale;

these include liming, sealing with subsoil and turf, and burning.

It has been argued (Richardson, 1956) that the presence

of large amounts of pyrites encourages the heating processes
which lead to burning of pit heaps. Whether or not this is
the case, it is true to say that when burning occurs much
sulphur is removed from the heap and hard masses of
clinker are produced below the surface. At the surface

there are, characteristically, either layers of small,

brittle, brick-red platey shales or light brown (or apricot)
coloured material which weathers rapidly to a fine powder.

Physically, the range of surface material is as wide on

burnt as on unburnt heaps. Immediately after burning

the surface contains the products of oxidation of pyrites
and these leach out rapidly (and are not replaced as happens
in unburnt heaps, see above) to provide a less toxic

medium than unburnt shale.

Shales and the young soils which develop from them are
not normally rich in essential mineral elements compared
with arable land or permanent pasture. Nevertheless most
pit heaps in Durham support some vegetation after 40
years (section 9.2.2) and many of them have closed
communities after 60 years. In some experiments surface
material was removed from young heaps to the Botany
Experimental garden and sown with seeds of recognised
pit heap grasses. Provided the material was watered to
bring the moisture content to near field capacity (section
9.2. lc) the seeds germinated and mature seeding plants
were supported by over 90% of the samples. Added
nitrogen, phosphorus and potash increased the yield.

(b) Temperature Pit heaps often have slopes of up to 43°
and with all possible aspects. The amount of solar radiation

86

angle between the incident rays and a perpendicular to the
surface, and, therefore, it is not surprising to find that

on many summer days southern slopes of pit heaps may
receive up to ten times the energy falling on north facing
slopes. It is also well known that black surfaces are better
absorbers of solar radiation than light coloured ones, and
consequently one might expect that black shales would have
higher daylight temperatures than lighter ones. It was
shown (Richardson, 1953, 1958) that the combined
effect of spoil colour, slope and aspectcould result in
very high temperatures on south facing slopes in summer.

In autumn and spring, southern slopes of pit heaps were
found to be covered with germinating seeds and seedlings
of grasses and herbs. This is because the south facing \
slopes, even in winter, have equable temperatures when |
the northern slopes are little above freezing point
(Greenwood, 1963). However, in the summer on bare
southern slopes, temperatures as high as 57°C were
recorded and the young plants withered and died. It :
was common to find surface temperatures exceeding !
50°C lasting for several hours around mid-day in June, 4
|
'

reaching a surface is proportional to the cosine of the
‘
‘\

July and August. Below the surface, at 75mm (3in) the

maximum temperatures reached were about 32°C, and at

150mm (6in) not more than 25°C. Protoplasm only

maintains its normal powers within a certain temperature i
range; and it is not only temperature but also its duration ‘
which determines whether fatal results will follow. It

follows that the absence of plants from the bare south facing
slopes might be attributed to the quantity of heat '
(temperature and duration of exposure combined) acting

directly on the shoot and root tissues at surface level, '
causing desiccation and subsequent death. Alternatively ;
it can be argued that the heat caused sufficient loss of
water in the surface layers to reduce the amount of
water available for absorption by roots — see this section
(c). When this available water is less than that lost in
transpiration, loss of turgor and death of the plant
follows.

It is well known that a plant cover, or a dry mulch at the

soil surface, reduces the daily temperature fluctuations

in the layers below the surface. The extent of this '
ameliorating effect of Agrostis tenuis, Holcus mollis and

Calluna vulgaris was investigated on several pit-heaps near
Chester-le-Street. When adjoining bare shale had daily 7
temperature ranges of 45°C (8°C to 53°C) at the surface,

a grass—herb cover reduced the range to about 1236

(12°C to 24°C).

Similar insulating properties were possessed by the layers
of moss and lichen, about 15mm thick, which occasionally
form an important part of the pit heap flora. When surface i
temperatures were over 50°C, the temperatures directly
underneath were nearer 25°C; in other words the heat

exchanges were concentrated in the thin boundary layer

of moss and lichen which served to keep the shale at a

reasonable temperature in summer and to conserve the

water present. The successful colonization of the pit

heap at Custon (NZ 267548) by Holcus mollis was

attributed to the presence of the moss—lichen layer.

(c) Available water For successful growth in any habitat,
plants must possess properties which meet the demands
of transpiration as well as the limitations of soil water
supply without incurring harmful water deficits. There are
generally recognised limits to the water content of a soil

profile in which plants will grow. The upper limit, called
the field capacity, is the amount of water held in fine
capillaries of a soil after rainfall when drainage from the
soil reaches zero; the lower limit, the wilting point, is

the water content at which turgor cannot be maintained
and permanent wilting occurs. At the wilting point

water is held by the soil with great tenacity; the moisture
tension is about 15 atmospheres, or pF 4.2 on the
logarithmic scale of tenacity. At field capacity water

is less tenaciously held than at the wilting point and on the
oF scale moisture.tensionis pF 2.5. The water held in

soil between field capacity and wilting point is available
to the plant for growth. Greenwood (1963 ) followed

for over a year the changes in the moisture tension which
occured at three depths on four aspects of a large conical
pit heap at Custon (NZ 267548). There was little
difference with aspect in the percentage of values above
pF 4.2 which occurred on the surface or 25mm (lin)
below the surface. However at 75mm (3in) depth there
was clear evidence that the S.E., S. and S.W. slopes were
generally about half as moist as the N.E. and N. slopes.
(Parts of the graphs showing pF variations recorded
between February 1961 and February 1962 are given in
Richardson and Greenwood, 1967.) These results were

in harmony with the distribution of plants on the heap
where the south, south east and south west remained bare
compared with the vigorous growth that occurred on the
north and north east slopes. It appears that in their

first year seedlings on spoil heaps may be subject to long
periods of high soil moisture tension. Their duration

and frequency will be the controlling factors in
determining the success of invading species. A succession
of dry summers with high soil temperatures and high pF
values would retard colonization just as several wet °
summers, with low pF values, would favour the process.
It is also clear from the results that any species with high
tates of root elongation, which takes the extremities
quickly down to depths greater than 75mm (3in) (see
above) will have increased chance of survival on pit heaps.
Slow growing herbs and grasses sown in spring would be
at a disadvantage compared with comparable seeds sown in
autumn. On the other hand trees and shrubs with long
roots can be artificially planted, say, down to 230mm (9in)
at which depth even in very dry weather the moisture
content does not fall below wilting point. Information is
accumulating for many mesophytic species indicating that,
provided the roots are in moist soil, the leafy shoots can
endure mid-day tem peratures of up to 60°C.

9.2.2 Plant succession

Pioneer, intermediate stage and climax species \n order to
trace probable stages in plant succession one can
investigate the flora of heaps of three or more age groups.
Early stage plants may be studied on heaps up to about 20
years old, later stages on heaps from 25 to SO years old
and probable climax vegetation on heaps of 80 years and
over. It is an advantage if observations are made on
neighbouring heaps which are in two or three of these
arbitrary classes. In general, the most sheltered

positions, and therefore the last to dry out (section 9.2.1(c))

after rainfall, were colonised first. Hollows and gullies
which faced north-east were such positions and from
them plants spread out slowly over the heap. All
previous work suggested that pit heap communities
contained plants found in the immediate vicinity e.g.

plants of woodland, moorland, pasture and hedgerow,
together with an assemblage of ‘waste place’ species. The
physical and chemical properties of the heap limits the
number of species which can initially act as colonists.
Later, as edaphic conditions are modified, other species
invade the still open communities, In the west of Durham
the climax of the vegetation is often a heather moorland
with some birch, while in the east of the county deciduous
woodland is likely to occur.

In order to examine more closely the distribution of
species primary data (see below ) was collected from 54
collieries in County Durham. Any one pit heap complex
composed say of several ridges might be arbitrarily divided
in 5 or 6 distinct areas based on age, aspect, slope or

nature of the shale. There were 237 such areas and they
were spread over the coal field from the western upland,
around the 240m (800ft) contour, eastwards into the Wear —
Tyne lowlands and finally to the coastal strip where the
Coal Measures are overlaid by Magnesian Limestone. Equal
numbers of areas were examined in each of the three
divisions of the county (see Fig. 9.1). In each case the
species were recorded and an assessment of quantity was
given using the following scale; (p) present — 1—20% cover;
(f) frequent — 21—40% cover; (a) abundant — 41—60%
cover; (d) dominant — 61—100% cover. Tables 9.1, 9.2,

9.3 summarise the occurrence of grasses, herbs, shrubs and
trees in the 237 areas.

River Tyne

HARTLEPOOL

REDCAR

>
ns Bem (10 mites)

AREA | Western Uplands
2 Wear-Tyne Lowlands
3 East Durham Lowlands

. Site of pit heap

Fig. 9.1 Map showing position of heaps examined and the
position of these heaps in three physical areas of Durham.

87

Table 9.1 Occurrence of grasses on 237 pit heap areas in Table 9.2 Occurrence of herbs on the 237 pit heap areas

County Durham in County Durham (all species rated (p))
Species Occurrence (%) Species Occurrence(%)
Agropyron repens 5 Achillea millefolium 1
Agrostis canina (p) 25 Artemisia vulgaris 8
Agrostis stolonifera (p) 1 Calluna vulgaris 6
Agrostis tenuis (p) 34 Carlina vulgaris 22
Agrostis tenuis (f) 28 Centaurea nigra 40
Agrostis tenuis (a) 14 Cerastium arvense 1
Agrostis tenuis (d) 6 Chamaenerion angustifolim 76
Aira caryophyliea (p) 1 Chrysanthemum leucanthemum 7
Aira praecox (p) 1 Cirsium vulgare 12
Alopecuris pratensis (p) 2 Digitalis purpurea 2
Ammophila arenaria (p) 1 Empetrum nigrum 1
Anthoxanthum odoratum (p) 1 Equisetum arvense 1
Arrhenatherum elatius (p) 44 Galium saxatile 2
Avena fatua (p) 1 Heracleum sphondylium 1
Brachypodium sylvaticum (p) 1 Hieracium pilosella 68
Dactylis glomerata (p) 38 Hieracium umbellatum 40
Dactylis glomerata (f) 17 Hieracium perproprinqguum 43
Dactylis glomerata (a) 7 Hypochaeris radicata 1
Dactylis glomerata (d) 2 Lathyrus pratensis 1
Deschampsia caespitosa (p) 1 Linaria vulgaris 3
Descham psia flexuosa (p) 48 Lotus corniculatus 1
Festuca ovina (p) 6 Luzula campestris 1
Festuca rubra (p) 4 Melandrium album 1
Holcus lanatus (p) 21 Myostis arvensis 1
Holcus lanatus (f) 9 Plantago lanceolata 27
Holcus lanatus (a) 3 Potentilla reptans 3
Holcus mollis (p) 1 Potentilla erecta 1
Lolium perenne (p) 4 Pteridium aquilinum 6
Molinia caerulea (p) 7 Ranunculus acris 1
Nardus stricta (p) 4 Ranunculus repens 1
Poa annua (p) 1 Reseda lutea 7
Poa pratensis (p) 2 Reseda luteola 11
Vulpia bromiodes (p) 1 Rumex acetosa 5
Ce Rumex crispus 7/
Rumex acetosella 16
The chief grasses found on pit heaps in County Durham are Senecio jacobaea 16
bier See ae sigan tiahlt a Sete Sh if aise lanatus. Sea tes : 3
Arrhenatherum elatius, 44%, and Deschampsia flexuosa, Tanacetum vulgaris 3
48%, are widely distributed but are only rarely the Taraxacum officinale 1
adr henge rain er ea MM
abundant or dominant on 20% of the areas and altogether it Trifolium pratense 1
occurs on 82% of them. For Dactylis glomerata the Tussilago farfara 61
corresponding figures are 9% and 64%. iia digies 4
Vaccinium myrtillus 1
Vicia cracca 1

The main herbs were Centaurea nigra, Chamaenerion
angustifolium, Hieracium spp. (H. pilosella,

H. perpropinquum, H. umbellatum) Plantago lanceolata
and Tussilago farfara, all of which occurred on more than
a third of the 237 sites.

88

Table 9.3 Occurrence of trees and shrubs on the 237 pit
heap areas in County Durham

Species

Occurrence(% )

Acer pseudoplatanus
Alnus glutinosa

Betula (B. pubescens, B. verrucosa)
Crataegus monogyna
Ligustrum vulgare
Pinus sylvestris
Populus nigra

Pyrus aria

Rosa spp.

Rubus spp.

Salix spp.

Sambucus nigra
Sarothamnus scoparius
Sorbus aucuparia

Ulex europaeus

Ulmus montana

—N
o-—-2£-"O0NNN

—

ry

-_ Cl
NNN WO

The principle trees and shrubs found commonly on the
pit heaps (Table 9.3) were: Betula, Crataegus, Rosa, Rubus,
Salix, Sarothamnus and Ulex.

The primary data for each area was entered first on a pro
forma and then the information was transferred to a
punched card. Thus a total of 237 cards was used in the
analysis of the vegetation and each card contained the
following information:

(a) Species occurring on the heap

(b) altitude in 6 categories between 0 and 275 m
(900 ft)

(c) aspect in 5 categories: N, S, E, W or flat

(d) slope in 4 categories: level, O—10°, 10—20°, 20—35°

(e) nature of surface in 5 categories? black shale, red,
cinders, humus present or absent

(f) surrounding vegetation in 4 categories

(g) age of area in 3 categories: O—25 yr, 25—80 yr,
over 80 yr

(h) amount of plant cover in 6 categories; 0, O—20%,
20—40% , 40-60%, 60-80%, 80—100%.

In addition, the occurrence of grasses Agrostis tenuis,
Dactylis glomerata and Holcus lanatus was recorded on a 4
point scale, present, frequent, abundant, dominant and the
number of legume and umbellifer species on a 5 point scale.

Having selected a particular species, e.g. Dactylis glomerata
(f), cards containing this plant were removed from the pack
of 237 in the approved manner. Qut of the 237 cards 39
(or 16.5%) were removed i.e. D. glomerata (f), occurred in
39 areas. Further selections were then made from the 39
cards for all the variables listed above. The chi-squared

test was used to determine whether or not the observed
values varied from those expected if the distribution of

D. glomerata (f) was random and the calculations were
performed by a KDF9 English Electric computer (Shenton,
1967 for details). Initially 25 of the most commonly
occurring species were selected from Tables 9.1, 9.2, 9.3
for analysis; each species occurred on ten or more areas.
Eleven species (out of the 25) showed some apparent
dependence on altitude and these were: Agrostis

canina, A. tenuis (p), Arrhenatherum elatius, Calluna
vulgaris, Centaurea nigra, Hieracium perpropinquum,
Holcus lanatus, Plantago lanceolata, Rubus spp., Rumex
acetosella, Tussilago farfara.

It is not proposed to describe and account for each of
these species, but to consider two examples:

(a) Agrostis tenuis is related to altitude when it occurs
as a ‘present’ species and it appears to grow at lower
altitudes 30m to 100m (100 — 400ft) rather than at
150m to 275m (S00 — 900ft). However, in contrast,
there was no correlation between A. fenuis with
‘frequent’ occurrence and altitude. One could conclude
that colonization by A. tenuis is more likely to be
favoured by low than by high altitudes, but that once
it is established there is no variation with altitude.

(b) The case of Calluna vulgaris is interesting because the
analysis showed it was favoured by habitats at 150m
(500ft) but not by lower ones; it was significantly
absent from any of the 237 areas at 30, 60 and 120m
(100, 200 and 400ft) above sea level. However, at
Plawsworth 90m (300ft), Haswell 100m (350ft) and at
other places under 120m (400ft) not included in the
237 areas, C. vulgaris is found on pit heaps. Heather
moorlands in Durham are largely found above the
140m (450ft) contour, and the open spaces of newly
formed shale heaps, being in the vicinity of large
quantities of seeds, offer suitable habitats for young
plants. Below 140m (450ft) C. vulgaris is absent except
for a few isolated places and most pit heaps are outside
the range of its seeds. However, when a pit heap is
formed near to a small piece of moorland, as at
Washington and at Haswell, not only C. vulgaris but
also other moorland species (Richardson, 1956) take on
the role of colonists.

Example (b) may be used in support of the view that the
local seeding plants are probably more important than other
environmental factors in determining the flora of pit heaps.

This notion was supported by the analysis of the
distribution of 35 of the commonly occurring species from
Tables 9.1, 9.2, 9.3 with respect to aspect. Not one of the
sets of data showed any correlation with aspect (N, S, E, W
or flat, see above); nor was there any uniform correlation
with age. Betula was found as a colonist on some heaps
and as a late-comer on others. The same applies to
Chamaenerion angustifolium, Centaurea nigra, Hieracium
spp., Linaria vulgaris, Reseda luteola and Ulex. In contrast
the following species appear later in the succession, after
about 25 years when there is some humus in the surface
layers: Carduus nutans, Plantago lanceolata, Rosa spp.,
Rubus spp., Senecio jacobaea, Acer and Crataegus.

9.2.3 Conclusions which relate to artificial planting

The results emphasize that pit heaps are often extremely
unfavourable habitats because of their physical and
chemical properties, their slope and their aspect. Neverthe-
less, very few shale tips are completely sterile, and, given
time, closed plant communities usually develop. The main
conclusions are:

(a) Clearly the list of naturally occurring species
detailed in Tables 9.1, 9.2, 9.3 (together with their
frequency of occurrence and the stage in the
succession when they appear) is a basis for any
planting programme, whether this takes place on

89

existing heaps, or on partially or fully reclaimed
heaps

(b) The surface of the heap must be neither too compact
nor too loose and it must contain both sand-sized
(2mm) and clay-sized (0.002mm) particles.

(c) The pH value must not be too low -nor the amount of
toxic substances too high.

(d) The seed rate must be high to allow for casualties,
especially on south-facing slopes.

(e) Again, mainly with respect to southern slopes,
precautions should be taken to insulate the surface
of the heap from the heating and drying power ot
the sun.

9.3 Planted vegetation

9.3.1 Grass and herb planting experiments

Plants growing on bare but non-toxic flat surfaces on pit
heaps are not subject to the same stresses as those
growing on the slopes, particularly on south facing slopes,
and it is relatively easier to establish a grass—herb
community on flat areas. Except for control plants most
of the experiments reported here were performed on
30—40° slopes. Given moist conditions in spring or
autumn, seeds sown either on the surface or just below
the surface (by light raking) germinate well. If conditions
in the following summer are moist and cool the seedlings
generally grow into substantial well-rooted plants.

Small scale planting

(a) Kibblesworth (NZ 242563) The surface on the slopes
of the bare heap was composed of a mixture of loose,
unburnt shales and small coal, with little clay content.
Rainfall scarcely penetrated and ran off rapidly so that
after rain the pF of the surface layers quickly approached
pF 4.2 (wilting point). Furthermore, the pH was low

(pH 4.0 — 2.5) and pyritiferous material was present.
Briefly, only those plots which were heavily limed
beforehand, given a layer of clay or peat, and seeded at
34.0 — 65.0g per m? (1—2oz per yd”), supported a
reasonable sward. Agrostis tenuis was the most successful
colonist and it responded well to light dressings 16.0g per
m2 (%oz per yd”) of bone meal and of hoof and horn.

(b) Ravensworth (NZ260582) In contrast to Kibblesworth
the bare south slopes at Ravensworth had good water
holding properties, the pH was around pH 6.8 and the total
sulphur only amounted to about 0.2%. Seeds were sown in
plots and lightly raked and rolled. Agrostis tenuis did well,
closely followed in abundance by Dactylis glomerata and
Deschampsia flexuosa. Festuca rubra did moderately

well. Seed rates as low as 8.0g/m? (%40z/yd?)

produced good results and all grasses responded to light
dressing with fertilizer (see above).

(c) South Moor (NZ 193516) The bare slopes did not have
the low water holding capacity of the Kibblesworth

slopes, but also they did not contain appreciable amounts
of sulphur. Seeds of A. tenuis, D. glomerata and D. flexuosa
were sown at rates from 8.0g to 15.0g per m2 (%4—1%4oz
per yd?) and raked in. The ground was made as firm as
possible. Following autumn sowing, germination and
growth of the seedlings was encouraging. However, in the
following spring and summer, drought conditions caused
excessive water loss from the top 50mm (2in) and heavy

90

casualties occurred. Once again plants of A. tenuis and to

a less extent D. glomerata, did well in adverse conditions
but generally their root growth was insufficient to carry

the extremities down to moist levels in the heap. The

herbs Lupinis alba, Medicago sativa, and Melilotus alba were
also sown together with seeds of Ulex, but all of these never
gained more than a foothold as colonists. Finally, four years
after the original planting, all the species (herbs and grasses)
were reduced to a few representative plants. Control plants
grown on shale in the Botany Experimental Garden and
well-watered produced massive growth.

The plants on the slopes of South Moor did not survive
because there was excessive drying from the loose,
unprotected surface. At Ravensworth the surface texture
helped the conserve moisture, and at Kibblesworth the
layer of clay or peat performed the same function. These
experiments emphasize that unless it is possible to water
young herbs and grasses on newly planted slopes in dry
conditions, special care should be taken to protect the
surface against drying out. Further experiments showed
that water could be conserved by covering the surface
with dry mulches of peat, straw and wood cellulose after
the seeds were sown. As the observations with Holcus
mollis had shown (section 9.2.1(b)) a thin layer (e.g.
10mm) was sufficient to insulate the soil against the sun’s
radiation and to keep moist the roots of seedlings. Dry
materials applied to the surface have the disadvantage of
being blown about in even slight winds and therefore
experiments were carried out to find a method of
holding the mulch in position. Fine-mesh hemp nets were
ideal for the purpose and were suitable for fairly large
areas as well as for small plots. Experience suggested that,
whereas dry mulches were suitable for small trial areas,
they would be costly if applied to large reclamation
areas. Liquid mulches such as Unisol 91 and various wood
cellulose pastes were compared with controls on the pit
heap at Ravensworth and were found to increase the
survival of seedlings by up to 100%, The wet mulch was
applied to the heap surface by means of a coarse type of
‘stirrup-pump’ and although this was satisfactory for
small plots it was evident that more powerful apparatus
would be required for steep slopes of large area. One
possibility was to employ the ‘hydromulching’ method in
which a soft paste of the selected mulch is sprayed from a
water-cannon mounted on a lorry tanker. This method
was adopted at Roddymoor (see below).

Large scale planting

Roddymoor (NZ 155364) The north and north east slopes
were levelled and compressed by bulldozer to give a firm
surface in which there were adequate amounts of small
clay and silt particles. The texture closely resembled that
at Ravensworth (see above) and further rolling was not
considered necessary. Water holding capacity was
generally good and there was no evidence of waterlogging.
The material was mainly neutral having pH values between
pH6.5 and 7.2. For ease of application and to provide a
surface insulating layer the seed mixtures were sown in a
paste of wood cellulose to which fertilizers were added (see
below ).

The north and north-east banks of the heap were
divided into fourteen plots of about 0.2 hectares (half an
acre) each which were seeded with a mixture of grass
seeds at various rates of application (see Fig. 9.2). Two

4 eee =

existing
scrub

cut off ditch

ee
N

—————
O 25 50 75 100m (330ft)

Fig. 9.2 Plan of north and north east slopes at Roddymoor.

methods of application were used to apply seeds to the
bank.

Referring to the plan of the different seeding plots on the
bank, plots C to N were seeded by the ‘hydromulching’

method and only plots A and B were seeded by the ‘glob’

seeding method. Plot A unlike plots B to N, which were
seeded with a mixture containing only grass species,
contained only one grass species, the rest of the mixture.
consisting of tree and herb species. All seeding was on the
bare shale which had had no topsoil added to the surface.

The seed mixture for plot A consisted of the following
species and its rate of application is given below.

kg /ha (Ib/acre)
Festuca rubra 16.8 (15)
Trifolium repens 9.0 (8)
Alnus glutinosa 2.2 (2)
Fraxinus excelsior 11 (1)
Acer pseudoplatanus 1 (1)
Betula pubescens 1.1 (1)
Total 31.3 (28)

Plots B to N were all seeded with the same type of seed
mixture using three rates of seed application of 84, 112,
168 kg/ha (75, 100 and 150 lb/acre). At these three rates
the grasses making up the total seed mixtures were as
shown in Table 9.4.

watercourse

N M

1 |
The thirteen plots (B—N) shown in Fig. 9.2 were seeded as
in Table 9.5.

Table 9.5 Seed rates employed on the plots at
Roddymoor

Plot Method Rate of application
kg/ha (Ib/acre)

B Glob 85 (75)
G Hydromulching 170 (150)
D * 85 (75)
E 112 (100)
F 112 (100)
G 112 (100)
H 85 (75)
I . 170 (150)
J - 85 (75)
K ae 112 (100)
E ~ 85 (75)
M st 85 (75)
N 85 (75)

Table 9.4 Composition of seed mixtures used at Roddymoor

Rate of application kg/ha (ib/acre)

Species 84 (75) 112 (100) 168 (150)
Agrostis tenuis (3.75) 5.6 (5) 8.4 (7.5)
Dactylis glomerata $.137 4.2 (3.75) 5.6 (5) 8.4 (7.5)
$.143 4.2 (3.75) 5.6 (5) 8.4 (7.5)
S.26 4.2 (3.75) 5.6 (5) 8.4 (7.5)
Festuca rubra S.59 38 (33.75) 50.4 (45) 84.6 (75.6)
F. rubra communtata 15.3 (13.125) 19.6 (17.5 29.4 (26.25)
F. tenuifolia 15.3 (13.125) 19.6(17.5) 29.4 (26.25)

srass seeds, fertiliser, and mulch were mixed and
1 the top of the spoil heap down on to the
*s of the north bank. The mulch consisted of wood
cellulose applied at 760 kg/ha (681 Ib/acre) giving
theoretical depth of 1.6mm (one sixteenth of an inch)
This application of a mulch with the seeds was to afford
some conservation of water and insulation against the sun’s
rays to the surface of the spoil heap on the slope. The
seeds on the north and north-east banks were sown on
23—26 August 1968 with 500 kg/ha (4 cwt/acre) of
Fisons 53 fertiliser (N12-P24-KO), except plot M which
not have any fertiliser applied at the time of sowing.
4 further application of fertiliser, Fisons low nitrogen 55
(8—20—16), was applied to the north slope, but not to
plots M and N, at a rate of 250 kg/ha (2 cwt/acre) during
May 1969

ulG

Sam ples of shale taken from various sites on the north bank
were air dried and sieved through a size 6 mesh, and then
subjected to close examination to see whether the shale
contained any remains of the cellulose mulch used for
hydromulching. None of the shales appeared to have any
remains of the mulch as could be expected if micro-
organisms were present in the soil which were active in
breaking down the cellulose to its basic constituents. This
indicated that the shale was in some respects fertile or

was becoming fertile.

Table 9.6 Occurrence of grasses and herbs at Roddym oor
1 year after sowing

A number of sites 1m X 1m were chosen at random; the
species of plants and their approximate distribution were
recorded. These sites were marked by means of labels

fixed on posts placed in the shale in order that the sites
could be revisited occasionally to record the performance
of the different grasses. Observations were made on 14 July
1969, and these are given in Table 9.6.

From the table it can be seen that the species list, both
herbs and grasses, is much longer than the planted species
list. The most obvious species not expectedto be in the
seed sown in August 1968, but growing strongly on the
north bank in July 1969 was Lolium multiflorum. It

can be seen in the photograph (Fig. 9.3) that the tall dense
Italian rye grass growing on the right of the picture
finishes in line with the seeding plot post at the top left of
the photograph. Although the rye grass occurs on all the
north bank in different frequencies, the greatest cover is at
the west end of the slope. This grass flowered during the
summer of 1969 and set seed which was viable; at the end
of August the seeds germinated on large areas of shale
which previously had little or no grass cover, as well as in
the grass sward already present. This grass L. multiflorum
was the most prolific seed-setting grass on the whole heap,
and may prove to be a successful plant on spoil heaps during
the first years of growth of a grass sward.

Site number
1.23 4557657 S839) 00) 1s

Species

12 13

14

Agropyron
repens p - -- -- - -
Agrostis

tenuis PpPppppp
Dactylis

glomerata

(flowering) ——-—-Tr p—--Ipp —-
D. glomerata
(non-flowering)
Deschampsia
flexuosa - r — _
Festuca rubra

commutata —-------pppp -
F. rubra rubra

F. tenuifolia

|
cy Oo
RS

|

|

Holcus lanatus —fppp
Lolium

mul!/tiflorum fi —— pi fip if ft ipp ot. id
Phleum
bertolonii

Poa annua
Capsella
bursa-pastoris
Ranunculus
acris a ee eS ae =
Reseda

luteola

Rumex
obtusifolium Pp =: = =a

Trifolium
repens ee ee

a ee

92

P

at Roddymoor.

Fig. 9.3 Growth of Lo/ium multiflorum on a steep slope

Agrostis tenuis, one of the first natural colonisers of pit
heaps, and one of the most commonly found grasses on
heaps also proved itself to be a successful plant when
seeded on to spoil, at least during the first year of growth
observed at Roddymoor. It set seed quite profusely but no
observations were made to see whether or not this seed
was Viable.

Dactylis glomerata during the summer was observed to be
varying in performance in different localities on the north
bank. Some plants were seen to be flowering and some
were not. The non flowering plants seemed to have poorer
growth than the flowering plants (see Table 9.6). This
could show that the grass was not as suitable as A. fenuis
for spoil heap colonisation, at least, in the first few

years of the production of a grass sward.

On nine of the sites chosen for the observation of the
performance of the grasses, Festuca rubra commutata
seemed to be absent; in contrast F. rubra rubra had taken
well and was growing strongly on eleven out of fourteen
sites; F. tenuifolia was only found on three of the sites.

Several additional species of grass (which were not in the
original mixtures) were observed; they were probably
being introduced by the action of wind from neighbouring
areas and this was also true of several herb species (see
Table 9.6).

The glob seeded plot (plot A) which was seeded with only
one grass species and the rest of the mixture consisting of
tree and shrub species was observed during the whole of
the spring, summer and autumn, but no tree seedlings
were observed to have successfully germinated during
1969. This plot, as mentioned above, was covered with a,
tall vigorous growth of Lolium multiflorum.

9.3.2 Tree and shrub planting

Small scale experiments Early records of trees. andshrubs
growing on pit heaps in Durham (e.g. Harrison, 1937,
Richardson, 1956) showed that Betula, Crataegus, Rosa,
Rubus occurred most frequently and this was confirmed
by Shenton’s extensive researches (see Table 9.3). Detailed
examination of sites showed that on most Betula was a
pioneer plant on both burnt and unburnt heaps and,
where there was a nearby source of seeds e.g. at Urpeth
(NZ 248555), there was rapid spread of this tree to form
an almost pure stand of birch. Furthermore, Betula was
able to survive in exposed positions and often reached the
tops of high slopes. Acer was frequent in very old heaps
which were low mounds, and in sheltered places on
unburnt heaps. The position of Alnus as a pit heap plant
is important. Alnus glutinosa Gaertn. is described by
Harrison and Temperley (1939) as a native in north-

east England, occurring by stream sides and in wet places
and low country. There is no example known to the
present writers of this plant acting as a natural colonist
of pit heaps in County Durham. Nevertheless, it has long
been recognised here that this plant (as its introduced
cogenor A. incana was later recognised) could do well on
poor soils, and indeed it was one of the species used in
1928 on the old pit heap at Houghall (section 9.1) and
elsewhere (see Whyte and Sisam, 1949).

Small scale experiments were set up on pit heap slopes at
Ravensworth (NZ 260582) Kibblesworth (NZ 242563)
Ouston (NZ 267548) Harraton (NZ 291539) and Urpeth
(NZ 248555). Plots were laid out on 30° to 40° slopes

which were (a) bare and about 8—16 years old, (b) with a
plant cover of about 50% and 25—30 years old. The
following conclusions were made:

(a) The ground vegetation must be well established before
a ‘slit’ method of planting can be usefully employed.
Deep hold planting (using spades) was more satisfactory
and three variations were employed. Most heaps contain
enough moisture to support colonising or planted
species provided the roots penetrate to the appropriate
depth (section 9.2.1(c)). To improve the water-holding
capacity of the shale a spadeful of loam soil was
placed in the hole below the roots and another spadeful
above the roots before the soil was firmed around the
stem. This procedure stimulated root growth in the
first year and treated plants made increased growth
compared with those placed directly on to the shale.

It was time-taking, awkward, and wasteful of soil to
apply soil from buckets or sacks carried along steep..,
unstable slopes. The following procedure was therefore
adopted. The tree roots were surrounded by soil
contained in hessian sandbags tied at the neck. This
operation was performed at convenient points along the
top or bottom of the steep slopes and the bagged trees
were then easily transported e.g. by sledge, to the
prepared holes.

(b) Asa result of the small scale tree planting experiments
carried out at the 5 sites listed, it was possible to
classify the performance of the species used as follows:

(i) good growth Alnus, Betula;

(ii) moderate growth Crataegus, Sorbus aucuparia;

(iii) poor growth Acer, Populus, Sambucus,
Ulex.

It was not uncommon to find that all the Acer and
Populus had died back after a few years in which time
Alnus and Betula had grown on strongly.

The experiment demonstrated the im portance of
selecting the best possible specimens for planting on

pit heap slopes. The ideal sapling is probably one which
is about three feet tall and possesses a well developed
root system. On these difficult sites the planting of
‘whips’ and ‘wolves’ could be inviting a heavy
beating-up programme.

(c) In the first years after planting there was often damage
to the stems of trees due to friction caused by movement
in the wind. Also there could be high transpiration losses
from leafy shoots at a time when new root growth was
just beginning and this could lead to wilting which, if
prolonged, resulted in the death of the sapling. Much
benefit was derived from cutting back the young
trees to a height of under two feet; this produced a
better balance between root and shoot, and eliminated
the causes of damage as indicated above.

(d) Much benefit accrued from the quick transfer of trees
from the nursery to their permanent places on the pit
heap. It was clear that in a large scale planting scheme
small batches of trees taken direct from nursery to
site, eliminating any temporary ‘heelingin’, would assist
quick establishment and also eliminate the delay and
cost of beating-up. Pit heap slopes are usually very
exacting habitats and it should be strongly emphasized
that extra special care (even at some additional cost)
should be given initially along the lines suggested in the

93

sections above. This will lead to better tree growth,
early establishment of a green cover, and will probably
save time and money in the long run.

Large scale planting The Durham County Council made a
notable contribution to landscape improvement when it
acquired a number of abandoned pit heaps, and, largely
between 1956 and 1959, planted them with trees. In
1966 it was decided to examine a number of these heaps
and to report on the growth and development of the
planted species with some reference also to the naturally
occurring species. Some attempt was made to correlate
the observed growth with the chief environmental
factors. An ideal analysis would involve a comparison
between past and present plant species, but unfortunately
no records were made of the vegetation present before
tree planting commenced or of detailed beating-up. The
following nine sites were selected for inspection from a
total of thirty because they provided a wide range of
geographical position, parent material, and surrounding
species (map references and areas planted, in hectares
and acres, are given):

(1) Littleburn (NZ 257397) 5.366 ha
(2) Croxdale (NZ 263374) 5.554ha
(3) South Moor (NZ 192516) 2.303 ha

(13.26 acres)
(13.70 acres)
( 5.69 acres)

—

(4) Tursdale (NZ 302363) 3.568ha ( 8.57 acres)
(5) Twizell (NZ 223523) 1465ha ( 3.62 acres)
(6) East

Tanfield (NZ 196550) 1.578ha_ ( 3.90 acres)
(7) Gloucester

Road (NZ 115507) 3.84Sha ( 9.50 acres)
(8) High Spen (NZ 138597) 1.457ha ( 3.60 acres)

(9) South Pelaw (NZ 270527) 3.841ha ( 9.49 acres)
Establishment of plantations When the trees were planted
strict precautions were taken. The bundles of trees were
loosened and heeled into good soil at the base of the spoil
heap, and steps were taken to prevent damage by vermin.
Unplanted trees were carried in sacks in order to prevent
wind damage to the roots. Trees were kept out of the
ground for the shortest possible time and were planted
when the ground was not frozen. Pits were dug in the heap
and the tree roots were spread outwards and downwards
before they were firmed in. All trees were planted to the
depth of the root collar. The heights of the principal

trees were as follows:

Conifers 0.45m (18in) Acer pseudoplatanus 0.9—1.5m
(3—Sft) Betula 045—0.76m (18—30in) Alnus incana
0.45—0.76m (18—30in) Quercus robur 0.30—0.45m
(12—18in).

Except where otherwise stated all of the softwoods were
grown for two years in one soil then a further year in
another (i.e. 2 + 1). The trees were planted 1.22 X 1.22m
(4 x 4ft) apart, at approximately 6660/ha (2700/acre).

As a general rule mixtures of hardwoods and softwoods
were planted in groups of nine or sixteen in alternate lines.
All natural tree seedlings and saplings were retained and
preserved, but occasionally top growth was cut back to
allow satisfactory tree planting. More trees were planted
on some areas of the heap than on others as the number of
existing trees varied. Not only were the trees carefully
planted but at intervals of time replacement of failures
was carried out (beating-up). The same 1.22 X1.22m

94

(4 x 4ft) distance of planting was used in beating up as in
the original planting. Because the species used in beating up
operations occasionally varied from those in the initial
planting, the final pattern of trees on the heap varied
considerably in some cases from that first designed.

In order to prevent death of planted trees by intense
competition from existing species many of the heaps

were periodically weeded and this involved cutting back to
ground level all herbaceous and shrubby growth along the
rows of trees, and particularly over a radius of 0.45m
(18in) around each tree.

Observations were made at all of the selected sites in
August 1966 and the primary data were filed with the
Landscape Reclamation Project Office and the Durham
County Council. In order to illustrate the type of pit
heap planting carried out, one site, Littleburn,

was selected for detailed description.

Table 9.7 Species planted and areas covered at Littleburn

Area Size Species
ha (acres)
A, 1.17 (2.89) Populus x robusta inter-
Ap 0.61 = (1.50) Populus x euramericana spersed
P. ‘Serotina’ with

P. ‘Celrica’ edi

A3 0.08 (0.20) P. “Eugenei’
B 0.32 (0.78) Pinus contorata (1+1)
Cc 0.17 (0.41) Pinus nigra var. calabrica
3 rows Quercus borealis fringe

D 0.16 (0.39) Acer pseudoplatanus 25%
Pinus nigra var. calabrica 75%
E 0.25 (0.61) Pinus nigra var. 50%
Larix leptolepis 50%
F 0.21 (0.52) Larix leptolepis

Pinus contorta
G 0.13 (0.32) Pinus contorta
H, 0.09 (0.22) Pinus contorta
(0.16) Pinus contorta
H3 0.01 (0.02) Pinus contorta
Hg 0.012 (0.03) Pinus contorta
J 0.19 (0.48) Pinus contorta 331/;%
Quercus 331/3%
Acer pseudoplatanus 331/3%
0.4 (1.00) P. contorta (1+1)
0.09 (0.24) Betula pendula
0.11 (0.27) Betula pendula

K

i

M

N1 0.34 (0.83) Pinus nigra var.

N2 0.13 (0.32) Pinus nigra var.

P 0.112 (0.28) A/nus 50% Betula 50%

Q 0.32 (0.80) P. contorta 10% Quercus 10%
Acer 10% Betula 70%

R 0.15 (0.36) Betula 25% P. nigra var.
calabrica 75%

S 0.25 (0.63) Acer 50% Betula 50%

X 0.14 (0.35) Planted in 1964 with a

mixture of P. nigra,

P. contorta, P. sylvestris,
Laris, Picea abies, Alnus,
Betula

;

River Bro =

«.

6 25 DD 5 100m (330 ft)

i ane!

Section through heap

/, Main railway (LNER)

Fig. 9.4 Sketch plan of the pit heap at Littleburn.

(.

o = 50 75 100 m (330 ft)

Fig. 9.5 The pattern of planting at Littleburn in 1956.

95

Littleburn heap This complex heap lies between the main
Newcastle—London railway line and the River Browney at
Meadowfield. The heap is situated on ground which falls
steeply from west to east and is composed of a number

of flat-topped ridges with sides which slope at angles of
between 30—45°. Generally the ridges are only a few feet
above the surrounding land at their western ends but,
because of the contours of the land, the spurs at their
eastern ends tower up to a hundred feet above the flat river
banks (Fig. 9.4). The long west and north west end of the
heap complex was flattened for factory building and much
building rubble lies marginally around this part of the site.

The pattern of planting for the Littleburn heap is shown in
Fig 9.5 and Table 9.7 gives the species and the area in
1956.

An account of the subsequent beating-up and weeding
can be summarised from the record as follows:

Date Record

May 1957 Survival of Pinus fair; Acer and
Alnus satisfactory; Quercus and
Populus poor; smaller sized
P. contorta doing remarkably well.
No Larix seen.
Nov — Dec 1957 30% beating up of original species
(Populus inadvertently omitted).
P. contorta, 1300; Salix daphnoides,
275; Acer, 250; Betula, 100; Quercus,
100.

January 1960 Beaten up with P. contorta, 1200;
P. nigra, 1300; Alnus incana, 3000;
Acer, 2800; Betula, 700; Area
beaten up includes 0.4 ha (1 acre)
burned in August and 1.6 ha

(4 acre) originally planted with
Populus which has completely
failed.

December 1961 Beaten up with A /nus incana, 2000;

Acer, 800.

Weeding was carried out in 1957, 1958, 1959, 1961, 1963,
1964 and 1965.

General conclusions from the survey at Littleburn

(a) Pinus nigra var .calabrica was the most successful
conifer planted on the heap. It tolerated not only strong
south-westerly winds but also steep ‘south facing
slopes. Indeed this tree did better on steep slopes
(areas N1, E and F), reaching 3—3.6m (10—12ft) in
ten years, than it did on the flatter areas (e.g. area N2).

(b) Pinus contorta was less tolerant of exposure and was
not well developed on areas B, H1 and H2. It was also
sensitive to shading, and if planted where there is a
good tree cover, as a ‘beating-up’ plant, it did not fully
develop.

(c) Pinus sylvestris and Picea abies,recently planted on areas
X and Y showed moderate growth, seemed to be well
established and about to enter a period of more rapid
growth. Larix leptolepis was the least successful of all the

96

conifers and flourished only on the sheltered east side
of area F at the bottom of the slope; Larix was also
very poor on areas X and Y.

(d) Alnus incana and Betula pendula showed the best
growth amongst the hardwoods with the former not
quite achieving the high yearly increment of Betula.
Salix, Populus and Acer did badly on the actual spoil
heaps (although they did fairly well on the scrubland at
the base of the heap, e.g. Acer and Salix attained
satisfactory growth in area J). Quercus robur was
largely unsuccessful but Q. borealis, planted on shale in
area C, showed good growth.

Vandalism had occurred along part of area F with some
Larix uprooted and others chopped down — the initial
failure of Populus in area Al may have been due to this.
Nevertheless, as Fig 9.6 shows, there was not much
damage by vandals when the trees were well established.
Littleburn heap being remote from the village, coupled
with diligent beating-up, are probably the main factors
responsible for the excellent result. There was no
evidence in favour of weeding for hardwoods whichwere
0.6 — 0.9m (2—3ft) at the time of planting. However, for
the conifers, much less in height at planting, weeding in a
circle around each plant was beneficial. If the

colonising herbs and grasses are otherwise left undisturbed
they help to bind the soil and increase its fertility.

In common with conditions on many sites the ‘soil’ varied
greatly from place to place on the site at Littleburn. In
some places the shale was red and burnt, in others grey/
black and unburnt. Within these two groups the soil

varied from raw shale to shale mixed to a depth of

76mm (3in) with dead and decaying organic matter.
Similarly the pH ranged from values of 3.2 to 6.0, and the
soil water available to plants for their grow th varied from
8% to 24%. Furthermore, the aspect and slope of the

heap changed from place to place, e.g. area N1 faced south
east with a steep slope of 35°—40°; area B faced west
with a gentle slope of 10°. Clearly with a uniform soil
throughout the site some firm conclusions relating, say

to the effect of slope and aspect on the growth of the
different planted trees might have been made. However,
with the large and random varieties which existed only very
broad conclusions may be drawn. In some ways the position
was clarified when all the nine sites listed above were
considered collectively and this is done in the discussion
below. All the sites were examined in the same way as
Littleburn and the results were similarly recorded.

9.3.3 Conclusions on tree planting

There are only eight tree and shrub species which occur
commonly and naturally as early colonists on pit heaps in
Durham, and these are Betula, Salix, Crataegus, Quercus,
Rosa, Rubus, Ulex and Sarothamnus. In the tree-planting
experiment on nine sites now reported, eighteen species
were employed, of which only four (Betula, Salix, Quercus
and Rosa) are in the list of colonists. The remaining
fourteen ‘introduced’ species are listed in Table 9.8.

Each of the nine sites listed above was divided into smaller
areas for planting out. For example, at Littleburn there
were 25 areas (A to Y, seeTable 9.7) making up the whole
site of 5.5 ha (13.6 acres) and at Gloucester Road the

site of 3.84 ha (9.5 acres) was divided into 5 areas.
Altogether the 9 sites contained 38.0 ha (94 acres) and, in

Fig. 9.6 Growth of planted trees at Littleburn.

round figures, 203,000 trees were planted on the nine
sites either at the main planting or in the later beating-up
operations. The total number of each species planted

was between 100 for Rosa and 86,000 for P. contorta (see
Table 9.8) and clearly the large variation in numbers will
have to be taken into consideration when conclusions

are drawn about the degree of success.

Classification of the growth made by the trees was done by
means of the following arbitrary categories and was based
on ten years growth on the pit heaps

(i) height greater than 2.1m (7ft) — good (G)

(ii) between 2.1m and 1.4m (7ft and 4.5ft)
(M)

(iii) between 1.4m and 0.9m (4.5ft and 3ft)

(iv) less than 0.9m (3ft) - poor (P)

moderate

fair (F)

Measurements of twenth-five trees of each species in an
area were used to give the information contained in Table
9.9. Where there was less than 20% survival the plantation
was described as sparse

The most successful hardwoods were Alnus and Betula, both
of which were planted in large quantities (25,000 and
15,000). The percentage survival was good and the growth
rate satisfactory. Populus, Acer, Fagus, Prunus, Quercus
robur must be considered as failures both in numbers which

survived and in growth rate of individual trees. Salix and
Robinia had low survival rates but individual plants,

once established, did fairly well. Quercus borealis (3350)
planted) survived in encouraging numbers, and, after slow
initial growth, formed a useful addition to the list of
successes. Rosa (100 planted) was not used in large enough
numbers to allow any conclusions to be made

An important experiment was carned out at Tursdale

where the following species were planted in 10 lines running
across the heap from west to east, a distance of 137m (150
yd): Larix leptolepis, Pinus contorta, P. nigra var. calabrica,
P. sylvestris, Acer pseudoplatanus, Alnus incana, Betula
pendula, Fagus sylvatica, Quercus borealis, Robinia
pseudoacacia. There were 100 trees in each line and the
pattern was repeated five times to give a total area planted
of 1.18 ha (2.92 acres). 500 each of the 10 species were
planted. The trees were examined in 1966, 6% years after
planting. Fagus and Acer were represented by a few plants
showing poor growth butno R

hand Alnus and Betula survived in staisfactory numbers and

binia survived. On the other

the average height attained in 6% years was 1.8m (6ft). The

best specimens had grown to between 3.7m and 4.6m

(12 and 1Sft). Quercus borealis survived in small numbers

and showed a low growth rate. A similar picture was
presented at South Moor where Pinus contorta (1600),

P. sylvestris (400), Betula (150), Acer (500) and Robinia

™~

©

Table 9.8 Tree planting at nine sites in County Durham

Species Total Littleburn Croxdale South Tursdale Twizell East Glou High Sth

Numbers Moor Tan. Rd. Spen Pelaw |
Pinus contorta 86,882 Pp ) p p p ) p p p
P. nigra var. calabrica 22,635 Pp Pp Pp ) x x p p x
P. sylvestris 6600 Pp x x Pp p x x x x
Larix decidua 4106 Pp x p p p x p p x
Picea abies 406 p x x x x “8 x x x ;
P. sitchensis 135 x Pp x x x x x x x
Acer pseudoplatanus 21,012 p p P p Pp p p p p
Populus spp. 13,093 x x x x x x % ) x
Salix daphnoides 375 p x Xx x: p ne x x ze
Betula pendula 16,651 p p Pp Pp x x p p p 4
Alnus incana 24,459 Pp Pp x Pp p Pp Pp p p ,
Quercus borealis 2350 Pp Pp p p x ne OBS p p i
Q. robra3 2066 p p x x p x x P x }
Fagus sylvatica 8800 x p p p p x x p x
Prunus avium 850 x p p p x p iS x
Robinia pseudoacacia 750 x p p p p x x x x
Fraxinus excelsior 1500 x x 4 x p p p x x
Rosa spp. 100 x x x x x p x x x

LT

Table 9.9. Growth of trees classified by height and frequency
(see text)

_——————L ST

Species Number Areas in each class Areas
of areas G M F ¢ designated
planted sparse

Pinus contorta 38 10 11 12 5 0

P. nigra var.

calabrica 23 7 8 3 4 1

P. sylvestris 7 1 Ss 1 2 1

Larix decidua 4 - 1 1 2 3

Picea abies 2 = 2 - = 0

P. sitchensis 1 - - - 1 1

Acer

pseudoplatanus 26 1 1 4 20 10

Populus spp. 1 - - - 1 1

Salix

daphnoides 5 2 1 1 1 2

Betula pendula 31 17 9 2 3 2

Alnus incana 28 17 4 6 1 1

Quercus

borealis 20 2 2 8 8 5

Q. robur 8 2, 2 2 4

Fagus sylvatica 5 = - 5 3

Prunus avium 7 - - - 5 3

Robinia 3 3 3

pseudoacacia 3 - - - 4 3

Fraxinus

excelsior 2 = = 1 1 1

Rosa spp. 1 - - - 1

98

(150) were planted in rows across the top of the flat heap
running from North to South. After eight years Acer and
Robinia were totai failures whereas Betula and the two
species of Prunus were surviving well and had reached a
height of between 0.9m and 1.5m (3ft and Sft).

The most successful softwoods were Pinus nigra and

P. contorta. They were equally at home on both north and
south facing slopes where they showed better growth at the
base and mid points of slopes than at the flat tops of

heaps, e.g. an average height of 3.0m (10ft) in 10 years, on
the lower slopes compared with 1.5m (Sft) on the tops. Both
species required seven or eight years before they began to
show a high growth rate. For example, in 1965, the growth
rate of Pinus nigra growing on slopes had increased from
about 0.08m to 0.46m (3 to 18in) per year, and for trees

on the tops to 0.2m (8in) per year. Similar results were
obtained for Pinus contorta and for this species there was
some evidence that, in situations exposed to the prevailing
wind, its growth rate was less than that of P. nigra. Pinus
sylvestris which was not planted in such quantity (and then
sometimes only in beating-up) showed it could become
established fairly quickly, for example, in areas X, Y at
Littleburn, the east slope at South Pelaw and at South

Moor.

The amount of damage to the trees by vandals varied from
site to site. It appeared to be slight at Croxdale and
Littleburn where the pit heaps were some distance 1.6km
and 3.2km (1 mile and 2 miles) from the nearest village. In
contrast, at places like High Spen and South Pelaw, where ;
the pit heaps were beside the houses, vandalism was severe '
and notices warning off maurauders were largely ignored.

At South Pelaw an area of approximately 44m by 22m

(40 yd by 20yd) on the south facing slope nearest the

houses was protected by means of 1.5m (Sft) chestnut

fencing. This precaution produced noteworthy results

(see Fig. 9.7) and it suggests that simple fencing carefully

sited could be effective in urban areas.

eas, ents os

Fig. 9.7 The fenced and unfenced parts of the pit heap at South Pelaw.

9.4 General conclusion

Pit heaps are often intransigent habitats where a number
of environmental factors act to retard plant growth.
Some of the main obstacles to the development of
vegetation on the steep slopes of pit heaps have been
investigated using physiological and ecological procedures
and ways have been suggested for ameliorating the
conditions. The main conclusion from the work reported
here must be that each pit heap (or derelict site)
scheduled for full reclamation should be first investigated
thoroughly by a person competent to advise on living
plants. It is unlikely that all sites will be identical or that
they should be given the same treatment to encourage
plant growth. The suggestion is that each reclamation site
should be treated separately, its physical and chemical
properties studied and the species available for planting
considered.

Some heaps will require considerable treatment, others
much less, but all should be treated as special cases. The
deeper the investigation leading to the formulation of the
final treatment the heap is to receive, the greater will be
the chances of success.

References

Brierley, J.K. (1956) Some preliminary observations on
the ecology of pit heaps. J. Ecol. Vol. 44, 383.

Greenwood, E.F. (1963) Studies in the Spread of Plants
on to Pit Heaps. Thesis, Univ. Durham.

Hall, 1.G. (1959) The ecology of disused pit heaps in
England. J. Ecol. Vol. 54, 689.
Harrison, J.W.H. (1937) An old pit heap. Vasculum,

Vol. 23, 53.

Harrison, J.W.H. and Temperley, G.W. (1939) The three
Northern Counties of England. Ed. Headlam, C.
Gateshead.

Pickersgill, B. (1971) Growth of Plants on Derelict Pit Heaps.
Thesis, Univ. Newcastle.

Richardson, J.A. (1953) A portable automatic soil
temperature recorder. J. Ecol. Vol. 41, 388.

Richardson, J.A. (1956) The Ecology and Physiology of Plants
Growing on Colliery Spoil Heaps, Clay Pits and
Quarries in County Durham. Thesis, Univ. Durham.

Richardson, J.A. (1957) Derelict pit heaps and their
vegetation. Planning Outlook, Vol. 4, 15.

Richardson, J.A. (1958) The effect of temperature on the
growth of plants on pit heaps. J. Ecol. Vol. 46, 537.

Richardson, J.A. (1964) Physics in Botany, London
Richardson, J.A. and Greenwood, E.F. (1967) Soil

moisture tension in relation to the colonization of
pit heaps. Proc. Univ, Newcastle Phil. Soc.
Vol. 1, 129

Whyte, R.O. and Sisam, J.W.B. (1949) The Establishment
of Vegetation on Industrial Waste Land. Comm.
Agric. Bur, No. 14. Aberystwyth.

Wood, R.F. and Thirgood, J.V. (1955) Tree planting on
colliery spoil heaps. Forestry Res. Paper. Vol. 17.

99

Chapter 10 Practical techniques for
establishing vegetation on derelict land

by C.J. Vyle

10.1 The suitability of materials to sustain
plant growth

In the light of experience in this project, the reasons for the
absence or sparsity of vegetation on derelict land are listed
as the dominance of rock material or stones, impermea-
bility of the soil to air or water, high water table, exposure
to extreme climate, atmospheric pollution, lack of plant
nutnents, inability to hold nutrients in soil, inability to
retain moisture in soil, toxic levels of chemicals, and
salinity. Some of these problem conditions can be over-
come through the design of a modified landscape, for
example, to offset inability to retain moisture by new
landform design which retards run-off. It is also possible
to plant vegetation of low nutrient requirement, e.g. cer-
tain grass—legume mixtures and trees with ‘pioneer’
characteristics, and to ameliorate the site conditions with
lime and fertilisers so that agricultural and other ‘advaneed’
species may be grown.

The conditions prevailing around the experimental sites pro-
vided a range of experience of problems often found in areas
in which derelict sites are located. Atmospheric pollution is
one of the most frequent of these. At Roddymoor,
however, no problem of this kind occurred and to a

degree this site served asa control. At Big Waters,

local sources of pollution in the form of burning pit

heaps are in the process of being removed. At Northbourne
Park, the nearby coal by-products plant emits fumes which
have given a tarry deposit on trees at the eastern end of the
site.

Exposure is a problem on the top of the Roddymoor

heap, which lies in open country at an altitude of
182—212m (600—700ft) above sea level, and at

Windynook, Felling which is 91—167m (300—SSOft)

above sea level. The Big Waters site, at only 6lm

(200ft) o.d., is nevertheless also exposed to strong

winds crossing the fairly open country to the west.

10.1.1 Lime requirements

(a) Roddymoor The shales encountered at Roddymoor
were black, grey, red, and mixtures of red and black;
other materials were slurry, coke breeze, building
foundations and stacked drift, subsoil and topsoil.

The shales were stony and had been heavily compacted
by earthmoving machines. Only a small amount of

lime was considered necessary for the Roddymoor site
as the pH levels of different parcels at the seeding

time were generally reasonable for grass establishment
for agricultural use.

(b) Big Waters The surface materials at Big Waters
were ash which had been used for agriculture, black
shale with a high coal content overlain with soil,
black shale with mixed shale and soil, and black

100

mixed shale with red mixed shale. These shales were
stony, but impermeability to air and water was not a
problem over most of the site. Areas of high water
table were present because of the levels at the bound-
aries of the site in relation to the water level in the
subsidence flash.

At Big Waters, the pH of the shales before regrading
varied between 2.8 and 3.8, and during regrading these
rose to 3.5—4.4. The agricultural ash area had a pH of
6.7 which rose to 71 on regrading. The imported
Dinnington shale had a pH of 8.0 to 8.5 with free
calcium carbonate present. Lime was applied to the
north area west of the road prior to the placing of
the Dinnington shale, and 2 ha (5 acres) to the south
was similarly treated.

Salinity has not been a problem on Big Waters and has
never exceeded the designated safe limit of 4 m.mho/cm.

At Big Waters, lime was applied at the appropriate rate
to achieve optimum conditions for plant growth at the
surface and part neutralisation of the sub-surface. The
pH of the black shale surface after liming was 7.0, and
the pH levels of the Dinnington shales after placement
were 7.7, 7.3 and 6.9 (parcels 3,4,5). The incorpo-
ration of lime to neutralize or part neutralize the sub-
surface may help to prevent deep rooted species from
going into check when their roots meet the less favour-
able medium.

(c) Maria Colliery Soil tests relating to lime and nutrient
requirements were made, and it was recorhmended that
shales with a low pH would be best buried under material
which would be less of a problem from the point of view
of management of the vegetation established on it. Pro-
vided that the more favourable shales were used, no

lime would be required.

(d) Northbourne Park The soil tests at Northbourne
Park revealed impoverished parent materials, including
some areas with a pH of 3.5.

10.1.2 Fertilizer requirements

(a) Roddymoor The shales were found to require
nitrogen and phosphate, but potassium was present

at an adequate level to sustain plant growth. The fer-
tilizer to meet the situation was applied at 500 kg/ha

(4 cwt/acre), yielding 48 units nitrogen (N)—96 units
phosphorus (P705)—0 Potassium (KO) units/

acre in 1968 to the seed bed. The first

application was not planned to meet the full deficiency,
and further applications (e.g. 80 units/acre and 100/
220 units/acre PyO5) in 1969 and 1970 respectively) were
made.

(b) Big Waters In two areas there was a severe lack of
phosphorus (427/470 units P>Os/acre), possibly owing to
the particular fixing properties of the acid parent
materials,

Those areas on shale which were sown with grass in the
Autumn of 1969 received 112 units PyOs/acre as basic
slag, and in addition 440 kg/ha (3% cwt/acre) of a com-
plete compound fertiliser yielding 35—70—70 units/acre,
bringing the total units in the seed beds to
35—182—70/acre.

The area previously used for agriculture had
35—70—70 units/acre applied.

Other areas which included subsequent tree planting
had 355 kg (7 cwt) of basic slag, yielding 1 12 units
P05; this was ripped into the 610 mm (2ft) surface
dressing of mixed red shale.

It is becoming apparent with increasing experience of
shale soils that phosphorus is a limiting factor, and may
help to explain why trees planted on some heaps have
remained in check.

(c) Maria Colliery The after use of the site for industry
will mean that the vegetational cover will be temporary,
and fertiliser treatments have been designed to ensure
that the sward is maintained until the time the site is
required for its intended use. In the seed bed

500 kg/ha (4cwt/acre) yielding 48—96—0 units/acre
was suggested, with two applications each of

500 kg/ha (4cwt/acre) yielding 160—80—80 units/acre
for the establishment period.

(d) Northbourne Park The main aim at Northbourne
Park was to re-establish a self-perpetuating soil fer-
tility cycle on existing grass areas by applying a high
level of a complete compound fertiliser. 1000 kg/ha
(8 cwt/acre) were applied to the existing cover,
yielding 80—120—80 units/acre. On areas with less
requirement 500 kg/ha (4 cwt/acre) were applied,
yielding 32—80—66 units/acre. On newly exposed
ash surfaces with little mechanism for fertiliser
retention, treatment with sewage sludge was under-
taken and this was followed by a fertiliser at a higher
rate. Where the material was particularly impover-
ished an additional application of a PK fertiliser was
made at 376 kg/ha (3ewt/acre) yielding O-60—60
units/acre. The limed area was covered with soil in
depths between 100 mm (4in) and 305 mm (12in) and
the soil fertilised at the high rate.

(e) Egerton Gardens At Egerton Gardens 880 kg/ha

(7 ewt/acre) of a complete compound fertiliser, yield-
Jing 105—105—105 units/acre was used. The aim in the
case of fertilising for recreational uses was to give a boost
to the existing grass cover and a good start to new grass.
During the course of maintenance, the grass cuttings

left on site will help to re-establish or establish a soil
fertility cycle, and minimal application of complete com-
pound fertiliser was made during the establishment
period.

10.1.3 Fertilisers — general comments

Where tree planting was the aim following autumn grass
establishment, no extra fertiliser was applied until the
spring of the following year, the intention being to main-

tain grass cover but not to cause undue competition with
the trees. Particularly on newly reclaimed sites, plans for
fertiliser applications should be flexible. Bearing in mind
the widely differing characteristics of shale soils and other
materials found on derelict sites, soil testing is imperative
and lime requirement tests should be included, especially
on those materials where there is a likelihood of increas-
ing acidity. In these circumstances such a test should be
undertaken as a matter of routine at least over the first
five year period. Nutrient requirement tests are also
vital, adjustments being made according to the type of
management which is to be adopted.

10.1.4 Fertilisers for trees and shrubs

On Roddymoor, apart from the fertiliser referred to in
10.1.2(a), all blocks received 57 g (20z) per plant of
basic slag, except for the D planting. Block B received
four treatments, three of which were superimposed on
the initial treatment of 57 gice.

treatment 1

57 g (2 02) basic slag
treatment 2

S57 g+57¢2
treatment 3

57 g+ 170g (6 oz)
treatment 4

57 g + 283 g(100z)

i.e. 114 g (4 02) basic slag
1.e. 227 g (8 02) basic slag
i.e. 340 g (12 02) basic slag

D planting on the north slope and on the north east
slope received:

Autumn (1969)

57 g (2 0z) + 113-g (4 0z) bone meal
Spring (1970)

57g +1132 hoof and horn

On Big Waters, basic slag was ripped into the surface prior
to seeding. Phosphorus deficits are to be made up with
applications of triple super phosphate and basic slag.
Recommended site preparation on sites showing severe
phosphate deficiency and at suitable gradients e.g. 400
units deficiency might include 1250 kg/ha (10 cwt/acre)
high grade slag ripped to a depth of 460 mm (I8in),
followed later by an application of 375 kg/ha (3 ewt/
acre) triple super phosphate cultivated to 225 mm

(9in) depth and finally finishing up with a complete
compound fertiliser harrowed into the seed bed prior

to grass sowing.

At Northbourne Park, no fertiliser dressing has been used
on the vegetated banks. Basic slag at 57 g (20z) and

113 g (402) could help to encourage more vigorous
growth of plants. Other trees were planted in grass

areas which had received varying levels of fertiliser in

the seed bed or for upgrading existing cover, but no
additional fertiliser to the trees has been applied.

10.2 Cultivation, preparation and grass
establishment

10.2.1 Seed bed preparation

(a) Ripping The most effective operation used in the
research for relieving compaction of existing and re-
graded surfaces was found to be ripping. This was to be
carried out at 915 mm (3ft) centres xX 610 mm (2ft)
depth. At Roddymoor under this specification, the
ripper tended to rise out of the ground, while at Big

101

Waters the same phenomenon occurred, leaving a

jepth at which ripping was effective of only 305 mm
(1ft) deep. Durham County Council have suggested
that this specification does not provide adequate cones
of shattering which meet, and they now specify ripp-
ing at 610 mm (2ft) centres X 610 mm (2ft) deep. It
was found, however, on the research sites that if the
machine operator drove slowly, using a Drott with its
three tines set at 915 mm (3ft) apart, adequate depths

of ripping were achieved

(b) Stone picking The removal of firstly, large stones, and
then smaller stones was undertaken. The tracking of
loaded trailers on damp soil and shale was a problem as

it led to wheel compaction, which in turn led to water
running down the tracks and eventually opening up small
gulleys (Fig. 10.1).

Fig. 10.1 Wheel track damage by stone picking trailers may
lead to small gulley formation which may be hazardous
later to tractor drivers and stock if not treated.

(c) Removal of hollows The hollows left by the removal
of the larger stones were smoothed out and filled in by
scrubbing. Spring tine and fixed tine cultivators have
also been used with success in removing hollows.

(d) Cultivation The normal processes of discing, harrow-
ing liming and fertilising were used on the research sites.
The application of lime before ripping had the advantage
of achieving a better distribution through the profile, and
thus helped to neutralize acid formed in the top 610 mm
(2ft). Basic slag incorporated in this way is also benefi-
cial for deep rooting species, and, in this respect, culti-
vating with fixed or spring tine cultivators can help to
incorporate basic slag to between 150 and 225 mm

(6 in and 9 in) depth.

Whilst accepting the normal practice of avoiding ferti-
liser and seed distribution at one and the same time, one

Fig. 10.2 Hydroseeding without mulch of a shallow
gradient area on ash over building foundations. CP2 mixture
was used. This method may have application where
conventional seeding cannot be undertaken because
underlying foundations would prevent cultivation by
normal agricultural implements.

Fig. 10.3 Eroding surface on the north facing slope at Roddymoor. Rills were in evidence prior to seeding. Mulch held the

slope surface until the grass became established.

102

area seeded in the cooler Autumn had a low nitrogen
fertiliser application preceding it on the same day, and
no subsequent damage occurred to the young seed-
lings.

10.2.2 Grass seed broadcasting

The conventional broadcasting machinery was used on
Roddymoor and Northbourne Park, i.e. a tractor-
drawn, spinner type. On Big Waters, distribution was
made by a hand-cranked broadcaster from the back of
a tractor-drawn trailer on areas where the seeding rate
was very low. With regard to rolling operations after
seeding, flat rolling was carried out with seed sown in
May 1969 at Roddymoor, and was found to give better
contact between the seed and the soil than with harrow-
ing alone. Flat rolling was not, however, used after
sowing in the Autumn.

10.2.3 Grass hydroseeding with mulch

At Roddymoor, a wood cellulose mulch, mixed with
water fertiliser and seeds, was distributed via extension
pipes to the least accessible parts of the north slope
The mulch helped to bind the eroding surface

(Fig. 10.3) and provided a favourable environment for
seed germination. High seeding rates and special seed
mixtures were used (see section 10.4. for details of
seeding rates and mixtures).

10.2.4 Grass hydroseeding without mulch

The application of seed and fertiliser, using water as
the medium for application, was also undertaken on
flatter areas where the slopes were not less than 1:15.
The machine used is shown in Fig. 10.2. Problems
were experienced because of ground conditions and
the weight of the machine (14 tonnes) leading to
bogging-down and rutting up to 305 mm (12in) depth
in some places. In these circumstances, harrowing of
the agricultural areas to cover the seed was undertaken.

10.2.5 Turf laying and herbaceous plants

Although the use of turves for establishing a grass cover
is unlikely to occur in reclamation projects, except in
special circumstances, an experiment was set up at the
west end of the north slope at Roddymoor. Erosion in
this position had acted against the establishment of a
seeded grass cover. It was also decided to assess the
ability of various grass and herbaceous species, grow-
ing originally under conditions of high altitude or
extreme exposure in Scotland, to establish in colliery
shale. The turves were 460 mm (18in) x 305 mm
(12in) X 100 mm (4in) deep, the shale being excava-
ted and the bottom of the hole forked over prior to
receiving the turves, which were laid so that they

were level with the surrounding shale (see section
10.6).

Experimental plantings of vigorous herbaceous plants
were undertaken on the stream banks at Big Waters,

although as in the case of turves, the occasions when

such plants are likely to be used in reclamation pro-
jects are limited.

10.3 Planting trees and shrubs

Several types of tree and shrub nursery stock were
planted on the sites, including forestry transplants,
oversized forestry stock, whips, ‘coppiced’ or stooled
seedlings, standards and semi-mature trees.

10.3.1 Trees

The different planting techniques used for experimental
and comparative purposes were the standard forestry
practice: mattock planting on areas with ‘natural’

soils; pit planting for the oversized forestry stock; the
poplars at Roddymoor and Big Waters; and the stan-
dards. The semi-mature trees at Egerton Gardens were
planted in accordance with B.S. 4043:1966.

10.3.2 Shrubs

Shrubs were planted at Northbourne Park into the exist-
ing vegetational cover, at Egerton Gardens into shale, at
Roddymoor into the shale surface, and at Big Waters into
shale or existing grass cover. The method used was the
conventional hole, large enough for the roots to be
spread. As anticipated, the shale ‘soils’ were particu-
larly subject to frost heave, and frequent attention to
firming in is recommended.

10.3.3 Cuttings

Considerable experimental work in planting was carried
out at the sites with cuttings, some being collected in
the countryside by local conservation bodies and by the
research staff, and some being obtained from the experi-
mental station at Long Ashton. Both kinds of cutting
were planted at Roddymoor and Big Waters into exist-
ing vegetated shale or spoil, and directly into shale. A
460 mm x 12 mm dia. (ISin x 4in dia.) spike was driven
into the different materials to depths between 225 mm
and 305 mm (9 in—12in) and the cutting inserted to
the appropriate depth using a hormone dip of naphth-
alene acetic acid with fungicide, Captan. At Roddy-
moor the hormone was applied to both Populus spp.
and Salix, but at Big Waters in half of the plot areas
cuttings were untreated. Salix spp. have rooted sat-
isfactorily without hormone, but standard practice
with Populus spp. is to use a dip.

10.4 Selection of species for grassland

10.4.1 Seed mixtures used and rates of application

Rates of seeding:

(a) Very low (V.L.) represents a low agricultural rate
associated with fertile soils. Up to 20 kg/ha
(18 Ib/acre).

(b) Low (L) represents a generous agricultural rate.
Up to 35 kg/ha (32 Ib/acre).

(c) Medium (M) represents approximately twice the
agricultural rate. Up to 75 kg/ha (66 Ib/acre).
(d) Heavy (H) represents three times the agricultural

rate. Up to 105 kg/ha (96 Ib/acre).
(e) Very heavy (V.H.) represents five times the agri-
cultural rate. Up to 175 kg/ha (160 Ib/acre).

The seed mixtures used are coded as G. (grass mixture)
or G.L. (grass—legume mixture). H indicates that the
mixture was applied by hydroseeding.

103

G.L.1 Recreational use on building debris covered with
100mm N 300mm (4in N 12in) soil

——_—_———————————— TT

Rate (M)
Species
kg/ha Ib/acre
Lolium perenne N.Z. 13.3 12.0
Phleum pratense S.50 6.7 6.0
Festuca pratensis S.53 ie lee 10.0
Festuca rubra S.59 5.0 4.5
Trifolium repens S.100 1.1 1.0
Trifolium hybridum 1.8 1.5
39.0 35.0

G.L.2 Parkland, recreation and forestry cover on shale
LD

Rate 1 (M) Rate 2 (H)

Species

kg/ha Ib/acre kg/ha _ Ib/acre
Lolium perenne S.24 13.3 12.0 27.0 24.0
Phleum pratense S.48 6.7 6.0 13.3 12.0
Festuca pratensis S.215 =11.1 10.0 22.0 20.0
Festuca rubra S.59 5.0 4.5 10.0 9.0
Trifolium repens S.123 1.8 1:5 3.4 3.0
Trifolium pratense S.184 1.1 1.0 2:3 2.0

39.0 35.0 78.0 70.0

eS ———— h———

G.L.5 H.5 Plant cover, prior to tree planting on mixed coke
breeze; shale with 100mm subsoil over building foundations;
shale (low maintenance)

Rate (M)

Species

kg/ha Ib/acre
Agrostis tenuis 5.6 5.0
Festuca rubra commutata 19.7 17.5
Festuca tenu/folia 19.7 17.5
Trifolium repens S.100 3.4 3.0
Trifolium pratense S.123 5.6 5.0

54.0 48.0

G.L.6 H.6 Plant cover prior to tree planting on shale
(low maintenance)

Rate (M)

Species

kg/ha Ib/acre
Agrostis tenuis 5.6 5.0
Festuca rubra S.59 19.6 17.5
Festuca tenuifolia 19.6 17.5
Trifolium pratense S.123 132 12.0

58.0 52.0

a a

G. H.4 (with mulch) Plant cover prior to tree planting, on

mixed shales — erosion protection

104

Rate 1(H) Rate 2(V.H.) Rate 3 (V.H.)

Species

kg/_ |b/ kg/ Ib/ kg/ Ib/

ha acre ha acre ha acre
Agrostis tenuis 42 oD 5.6 5.0 8.4 7/5)
Dactylis glomerata S.37 AD 315 5.6 5.0 84 7.5
Dactylis glomerata S.3143 4.2 3.75 5.6 5.0 8.4 7.5
Dactylis glomerata S.26 AVA) hy 5.6 5.0 8.4 7.5
Festuca rubra S.59 37.8 33.75 50.4 45.0 75.6 67.5
Festuca rubra commuta 14.7 13.125 19.6 17.5 29.4 26.25
Festuca tenuifolia 14.7 13.125 19.6 17.5 29.4 26.25

84.0 75.000 112.0 100.0 168.0 150.0

[a

G.L.7 H.1 Plant cover on coke breeze, to prevent
erosion (low maintenance)

Rate (L)

Species

kg/ha Ib/acre
Festuca rubra S.59 16.8 15.0
Medicago /upulina 9.0 8.0
(substituted for:
Lotus corniculatus) (9.0) (8.0)

25.8 23.0

G.L.18 Agricultural pasture on shale. A Lancashire C.C.
(L.C.T.) mixture

Rate (M)
Species
kg/ha Ib/acre

Lolium perenne S.24 11.1 10.0
Lolium perenne N.2Z. Ti 10.0
Dactylis glomerata S.341 7.9 7.0
Dactylis glomerata S.37 5.6 5.0
Phleum pratense S.48 3.8 3.5
Phleum pratense S.51 7.9 Flas
Festuca pratensis S.215 5.6 5.5
Festuca pratensis $.53 7.9 7.5
Trifolium repens S.100 > dS 2.5
Trifolium pratense S.123 3.8 3.5

~s 67.0 60.0

G.L.9 Cockle Park (C.P.) mixture. Agricultural pasture on
stored soil (Rate 1) and shale (Rate 2)

Rate 1 (M) Rate 2 (M)
Species
kg/ha Ib/acre kg/ha _ Ib/acre
Lolium perenne S.24 15.7 14.0 31.2 28.0

Dactylis glomerata S.37 7.9 7.0 15.6 14.0
Phleum pratense S.51 4.5 4.0 9.0 8.0
Trifolium repens S.100 2.3 2.0 4.5 4.0
Trifolium pratense $.123 3.4 3.0 6.7 6.0

33.8 30.0 67.0 60.0

G.L.10 Parkland, low maintenance on imported Dinnington
shale

Rate 1(V.L.) Rate 2 (V.L.)
Species

kg/ha Ib/acre

Ib/acre kg/ha

Phleum pratense S$.50 9.0 8.0 13.3 12.0
White Clover S.100 2.3 2.0 3.4 3.0

11.3 10.0 16.7 15.0

G.L.11 Agricultural mixture — Northumberland

Rate (L)
Species
kg/ha Ib/acre
Lolium perenne §.23 22.0 20.0
Festuca rubra S.59 5.6 5.0
Agrostis tenuis 2.3 2.0
Trifolium repens S.100 1.1 1.0
Trifolium repens Wild white 1.1 1.0
Trifolium hybridum 1.1 1.0
33.2 30.0
G.L.12 Plant cover prior to tree planting
Rate (L)
Species
kg/ha Ib/acre
Lolium multiflorum Westerwolds 10.1 9.0
Dactylis glomerata S.143 13.3 12.0
Poa trivialis 3.4 3.0
Festuca rubra 3.4 3.0
Trifolium repens S.100 fat 1.0
Trifolium repens Wild white 1.1 1.0
Trifolium hybridum 1.1 1.0
33.5 30.0

10¢

G.L.13 Agricultural mixture — Derbyshire, on shale

Rate (M)

Species

kg/ha Ib/acre
Lolium multiflorum Danish 22.0 20.0
Lolium perenne S.23 33.0 30.0
Trifolium repens N.Z. 3.4 3.0
Trifolium repens Kentish wild 1.1 1.0

59.5 54.0

as,

G.L.14 Temporary use on mixed topsoil and shale area

Rate (M)

Species

kg/ha Ib/acre
Festuca rubra S.59 112 10.0
Lolium perenne S.23 16.8 15.0
Phleum pratense S.48 3.4 3.0
Trifolium repens S.100 72 2.0
Poa pratensis 3.4 3.0
Agrostis tenuis 5.6 5.0

42.6 38.0

10.4.2? List of grass and legume species

Latin name

Lolium perenne
Lolium multiflorum
Dactylis glomerata
Festuca rubra rubra

F. rubra commutata
F. Tenuifolia

F. pratensis
Agrostis tenuis
Phleum pratense

P. bertolonii

Poa pratensis

Trifolium repens

T. pratense
T. hybridum
Lotus corniculatus

Medicago /upulina

English name

Perennial Rye-grass
Italian Rye-grass
Cocksfoot

Creeping Red
Fescue

Chewings Fescue
Hard Fescue
Meadow Fescue
Bent

Timothy

Small Timothy

Rough Stalked
Meadow Grass

White clover

Red clover
Alsike clover
Birdsfoot Trefoil
Black Medock

Strains
$23, S24, N.A.
Mother

Westerwolds,
Danish

$37, S341,
$143, S26

S59

$215, S53

S48, S51
S50

Kentish wild,
N.Z., S100,
S184, wild

$123

106

10.4.3 Performance of seed mixtures after
12 months

(a) G.L.1

Origin Based on a Lancashire mix (cocks-
foot element omitted).

Site Northbourne Park

Use Recreation

Comment Successful at medium rate
Dominant
species Rye-grass
(b) G.L.2
Origin As above
(i)
Site Northbourne Park
Use Recreation
Comment Successful at medium rate
Dominant
species Rye-grass, some patches of white clover
(ii)
Site Big Waters
Use Parkland
Comment Successful at medium and high rate
Dominant
species To be assessed
(c) G.L.S, H.5
Origin Based on suitability of individual species
Site (i) Roddymoor
(ii) Big Waters
Use Cover prior to forestry planting
Comment Successful at medium rates for cover
Dominant
species Part Red clover dominant

N.B. Part red clover dominant, may suppress trees below
450mm (1i4ft). 600mm (2ft) transplants and larger
unaffected. Suggest red clover removed from low
maintenance mixtures to be cut, or where small transplants
to be used.

(d) G.L.6, H.6

Origin As above

Site As above

Use As above

Comment As above

Dominant

species Suggest red clover substituted with
white clover

(e) G.L.7, HI

Origin As above

Site Roddymoor

Use Erosion control

Comment Successful at low rate

Dominant

species Fescue mainly dominant some areas
Medick dominant

(f) GHA

Origin As above

Site Roddymoor

Use Erosion control on steep slope

Comment Successful at heavy to very heavy
rates. Excellent cover over majority
of site. Cover disappears from area
with pH 3.5

Dominant

species Agrostis tenuis

(g) G.L.8, L.C.T.

Ongin Based on experience of Lancashire
County Planning Department on
performance of seeds in mixtures

Site Roddymoor

Use Agriculture

Comment Problems were met due to inade-
quate ripping depth, late sowings
and under surface heating
(350° C at 1.5m depth). Eventually

successful at medium rates.

Dominant

species In parts Timothy, and white clover
on areas of under surface heating

(h) G.L.9, CP.

Origin As above

Site (i) Roddymoor
(ii) Big Waters

Use Agriculture. Cover prior to
forestry planting

Comment Grass successful at medium rate

Dominant

species Rye-grass under agriculture.

Clover in forestry areas at

Wahi.

Origin Based on species used in a horti-
cultural ley for sowing down
orchard

Site Big Waters

Use Minimum maintenance

Comment Mixture successtul at very low

rate associated with good horti-
cultural soil

Dominant

species Timothy. White clover

(i) GLI

Origin N.A.A.S. (Newcastle)

Site Northumberland C.C. sites

Use Agriculture

Comment Low rate recommended

(k) G.L.12

Origin As above

Site As above

Use Cover prior to forestry planting

Comment Low rate recommended

(1) G.L.IZ

Origin N.A.A.S. (Derbyshire)

Site Derbyshire sites

Use Agricultural

Comment Successful at medium rate

(m) G.L.14

Origin Based on suitability of individual species

Site Maria Colliery

Use Cover prior to industrial use

Comment Apart from a small area on good top soil,
weed growth has severely limited the
growth of grass

10.4.4 Comments on seed mixture performance

(a) Roddymoor Whilst areas with a natural soil cover
were seeded with G.L.9 at a normal agricultural rate
(C.P.1), the shale areas were seeded at double the
standard agricultural rate with two mixture (C.P.
Rate 2 and LCT). The results on areas of red

shales plus mixed shales, and which were also
exposed, suggested that a seed mixture with a wide
range of species would be more appropriate.

The grass seed mixture G (H4) and seed mixtures
hydroseeded together with tree seed mixture

(H2 and H3) were sown at various rates to provide
protection against erosion on slopes, and as a cover
to assist in the subsequent establishment of trees.
The success of individual species in the seed mix-
ture G, at different sowing rates, is recorded in
Chapter 9.

Seeding at Roddymoor was undertaken during the
last week in August, and during September 1968,
the last sowing being made on October 4 on the
exposed Parcel 10. (Fig 10.4) Although there was
no sign of heating detectable by thermometer,
steaming became obvious during the winter months,
showing a high state of oxidation. Surface temper-
ature readings ranging between 50°C and C and
ambient were recorded with an air temperature of
0°C. A white clover sward now

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108

dominates some of these areas of high activity. Over
the rest of the site the clover content of the sward
is markedly reduced from what it should be.

6S (Fig 10.4) was sown in May 1969 and the
incorporation of farmyard manure in the seed bed
may have helped the seedlings over a difficult
moisture stress period. Elsewhere, seedlings on
shale suffered from drought, many of the seed-
lings being killed; some seed remained dormant
until Autumn and helped to infill some of the bare
areas.

(b) Big Waters Areas which were to be agriculturally
useful were sown with standard agricultural

mixtures at a generous rate (C.P. Rate |) and at
double rate (C.P. Rate 2).

Areas to be planted with trees were sown with an
agricultural mixture (C.P. Rate 1). The mixture was
found to be difficult to maintain around the trees
and is not recommended for cover prior to planting
unless wide spacings allow for, say, hay cropping as
a maintenance procedure.

(c) Maria Colliery The use of the site after grass
development will be of a temporary nature, pending
permanent uses, thus it was decided that soil diff-
erences need not be meticulously observed in the
selection of a seed mixture.

(d) Northbourne Park The areas for open space used
on Northbourne Park were sown at agricultural rates
(LCT). The rate was a generous agricultural appli-
cation but at about a third of the usual rate for open
space sowings. Species liable to form tufts (cocks-
foot) were omitted from the mixture (G.L.1 and
G.L.2). Areas sown for later tree planting had a
mixture of fine-leaved species sown at low rates,

but sufficient to give a good plant cover.

For areas to be planted later with trees or shrubs,

a fescue/bent mixture was used to give minimum
competition.

The May 1968 seeding of G.L.1 and G.L.2 germinated

very rapidly and gave excellent cover within six weeks.

Areas sown in November 1968 did not germinate until
Spring 1969. Spring sowings were made in 1969,
again in May, on two ash areas; one took and the
other failed.

10.5 Selection of tree and shrub species

The factors taken into account in species selection
were soil type, aspect, water table, use of the area
planted, ecological and visual appropriateness,
availability, and the need to include a wide range
for experimental purposes.

In the course of the experimental work, a consid-
erable number of species was planted, and records
kept of the materials into which the planting was
carried out, and into the subsequent perform-

ance. Because of the complexity of this inform-
ation, the major findings are summarised; these
inevitably include damage by vandalism etc., as well
as ‘natural’ failures.

10.5.1 Species used

Latin name

English name

Average
percentage

success after
12 months

on all sites

(a). Standard trees (planted at between 0.9 and 3.0 m

(3ft — 10ft) high)

Alnus glutinosa
Alnus incana

Alnus cordata

Alnus rubra

Acer platanoides
Acer pseudo-platanus
Betula pendula
Crataegus monogyna
Fraxinus excelsior
Populus alba
Populus canescens
Populus trichocarpa
Salix alba

Salix vitellina
Sorbus aria

Sorbus aucuparia
Sorbus domestica
Sorbus intermedia
Tilia platyphyllos

Common alder
Grey alder
Italian alder

Norway maple
Sycamore

Silver birch
Hawthorn
Common ash

White poplar

Grey poplar
Western balsam poplar
White willow
Golden willow
Whitebeam
Mountain ash
Service tree
Swedish whitebeam

Lime

71
90
90

(b) Semi mature trees (planted 6m — 7m (20ft — 24ft) high)

Acer pseudo-platanus
Betula pendula
Sorbus aucuparia

Sycamore
Silver birch
Mountain ash

0
0
0

(c) Forestry transplants or tree seedlings (planted 0.4m —
1.2m (1ft 4in — 4ft) high for 1 year + 1 year; 0.6m — 1.4m
(2ft — 4ft 8in) high for 2 years + 1 year)

Alnus glutinosa
Alnus incana

Betula pendula
Crataegus monogyna
Fagus sylvatica

Pinus nigra Var. austriaca

Pinus nigra vat .calabrica

Pinus sy/vestris
Populus alba

Pinus X berolinensis
Populus canescens

Populus tacamahaca
x tuchocupa

Prunus avium
Prunus padus

Common alder
Grey alder
Silver birch
Hawthorn
Beech
Austrian pine
Corsican pine
Scots pine
White poplar
Grey poplar
Balsam poplar

Gean
Bird cherry

109

Salix alba White willow 80
Salix alba ‘Liempole’ - 80
Sorbus aria Whitebeam 90
Sorbus aucuparia Mountain ash 83

(d) Stooled trees (planted cut back to 0.15m — 0.46m

Sam bucus nigra Common elder 7h}
Sambucus racemosa Red elder 90
Sorbus aucuparia Mountain ash 95
Prunus cerasifera Myrobalan plum 85
Robinia pseudoacacia Common acacia 100

(6in — 1ft Gin) high)

Betula pendula
Fraxinus excelsior
Fraxinus ornus
Populus alba
Sorbus aucuparia
Salix vitellina

(e) Shrubs — pot grown (planted 0.2m — 0.9m (8in — 3ft)

high)

Cotoneaster simonsii
Hedera hibernica

Hypernicum calycinum
(f) Shrubs — transplants (planted 0.4m — 1.4m (1ft 4in —

4ft 8in) high)

Berberis vulgaris

Cornus stolonifera var.
flaviramea

Cornus mas

Cornus alba sibirica
Cotoneaster simonsit
Hypericum calycinum
Mahonia aquifolium
Malus sylvestris
Ligustrum vulgare
Polygonum
baldschuanicum

Rosa moschata

Rosa canina

Rosa wichuriana
Rosa rubiginosa

Rosa spinossissima
Rosa rugosa

Rosa multiflora
Japonica

Rubus ‘Malling
Promise’

Rubus deliciosus
Rubus fruticosus
Rubus spectabilis
Salix purpurea
Salix cinerea
Salix caprea

Salix viminalis

110

Silver birch
Common ash
Manna ash
White poplar
Mountain ash

Golden willow

Irish ivy
St. John’s Wort

Yellow-bark dogwood

Cornelian cherry
Red-bark dogwood

St. John’s Wort
Applestock

Privet
Russian vine

Sweet Briar

Scotch rose

Common blackberry
Purple osier
Grey willow
Goat willow

Common osier

39
86
60
77
60
30

75
75
90

100

N/A
N/A

(q) Shrubs — stooled (planted 0.46m — 1.2m (1ft 8in —
4ft) high)

Corylus avellana Hazel 0
Cornus alba sibirica Red-bark dogwood 54
Salix caprea Goat willow 70

N/A signifies that an assessment has not been possible to
date.

10.5.2 Performance of various species

(a) Standard trees In general over all sites, trees
planted as standards survived and made growth. Alder
spp., poplars and Sorbus spp. being particularly
successful, while the most doubtful species were

ash and birch, although vandalism was a factor in

this respect. A special point is made in respect of
the Big Waters site where very dry weather con-
ditions prevailed during the Spring and early Summer
after planting, but after an initial check, the survi-
val rate was very high, due no doubt to the high
standard of planting carried out by the forestry

staff of the Northumberland County Council.

(b) Semi mature trees These were used experi-
mentally on one urban site Egerton Gardens, and
the total loss was due entirely to vandalism. It is
unfortunate that on urban sites, where trees planted
initially at a large size are desirable, failures due to
external circumstances are most likely to occur.

(c) Forestry transplants Despite the likelihood of
more failures than with the ‘individually’ planted
standard trees, the results from the species selected
were encouraging. Although the percentage of
success over all the sites for alder was lower than
for some other species, Alnus glutinosa was very
successful. Willows and poplars proved their use ful-
ness on reclaimed sites, and Scots pine was noted as
a successful conifer. Birch again proved an uncer-
tain species.

(d) Stooled trees Site conditions produced consid-
erable variation in the performance figures, but
mountain ash and white poplar were generally
regarded as successful. Despite the low figure for
willow, this genus is likely to perform well under
the stooling technique.

(e) Shrubs — pot grown The results were variable.
For example, the first planting of Hypericum had a
poor survival rate, but a second attempt in the follow-
ing year was successful.

(f) Shrubs — transplants Dogwood proved the most
reliable shrub, whilst Rosaspp. also proved useful
and gave visual interest at an early stage.

(g) Shrubs — stooled The results were achieved on a
site subject to much vandalism and atmospheric
pollution, and were sufficiently good to justify

this technique as worthwhile.

10.5.3 Cuttings

Several experimental plantings were made with tree
and shrub cuttings planted directly into the soil
material. This is a cheap and useful method of
developing a tree and shrub cover, and the follow-
ing summarises our experience to date.

Cuttings planted in a meadow habitat at Big Waters
suffered from grass competition, vandalism and
trespass by cows.

The Populus cuttings suffered from grass competition,
high water table and waterlogging during the growing
season. Areas where grass cover was sparse helped

cuttings of Salix and also cuttings of Cornus sanguinea
by making them less visible to vandals and by shading,
providing a more favourable microclimate for the

establishment of cuttings during the hot spell in June.

Populus cuttings at Roddymoor on the shale gave a
40% take. Where they were planted in meadow the
grass overtopped them and killed them. Salix cuttings
from Witton-le-Wear Nature Reserve were successful
giving an overall take of 66% with some plots giving
100%, the worst performance being 20%. The
Gosforth Park Willows especially the S. cinerea type
performed poorly, giving complete failure in some
cases and in no case was the take above 48%.

S. Fragilis gave a 92% take. The Salix from Long
Ashton were in the poorest material, ash over build-
ing foundations, and performance was varied.

S. cinerea failed completely, S. purpurea ‘Iretto’
gave a 58% take, S. daphnoides ‘Oxford Violet’
52%, S. viminalis ‘Mealy Tops’ 52%, S. viminalis
*Gigantea’ 30%, S. purpurea ‘Dicky Meadows’

32%, S. daphnoides ‘French Purple’, S. triandra

and S. daphnoides X caprea all gave takes under
15%. The best performance was from a 19mm
(0.7Sin) by 380mm (1ft 3in) viminalis type cutting
from Witton-le-Wear which put out two leaders,
one growing to 152Smm (5ft) and the other to
1170mm (3ft) in the season of planting.

10.6 Experimental turf plantings (see 10.2.5)

A number of turves from high altitude sites in the
north of Scotland were laid on an area at the
Roddymoor site.

(a) The western part of the area Here the surface
material was bare or sparsely vegetated shale, and
the dominant species in each turf and the place and
altitude of origin were as follows (reading from east
to west):

Nardus stricta (Slochd (S) 390m (1 300ft) ), Poa
trivialis (Corrischullie 330m (1100ft) ), Festuca
tenuifolia(S), Holcus lanatus (S), Phleum pratense
(S), H. mollis (S), Festuca ovina (Dalmagerry 271m
(904ft) ), Festuca rubra (S),Galium saxatile (S),

Poa pratensis (S), Agrostis tenuis (Tomdhu 195m
650ft), Agrostis canina Carrbridge (a) 330m

(1100ft) ), Deschampsia flexuosa (Ca), Anthoxanthum
odoratum (S), Trifolium repens, Vaccinium vitis-
idaea, Luzula spicata (S).

The results of this experiment were generally success-
ful. The dominant species in each turf now varies
from being ‘present’ on the turf to being ‘dominant’.
For example Nardus stricta and Festuca tenuifolia
were found to be frequent on their respective turves,
but Vaccinium vitis-idaea was found to be only present
on its turf.

(b) The eastern turves were laid on a bare slope from
which the sown grass had died out. This bare area was
found to have a pH of 3.4 and a phosphorus deficit

of 400 units at the end of 1969, thus the turf species
have been subjected to severe conditions. Six rows of
turves were planted across the slope, two thirds down
the slope to help prevent erosion. The number of
turves in each row varied from four to eleven.

The rows are numbered from the top of the slope (south)

to the bottom of the slope (north) and the dominant
species in each turf are listed reading from east to west
across each row.

(i) Rubus chamaemorus 2, Salix herbacea 4 (Dunnet
Head, Pentland Firth 120m (400ft) )

(ii) - Vaccinium vitis-idaea 3 (S), Trifolium repens 2
(S), Betula nana Hills of N.W. of Rogart,
Sutherland 360m (1200ft) Vaccinium myrtillus
3(S)

(iii) Lathyrus montanus 4 (Nethy Bridge (N.B.) 210 m
(700ft) ), Veronica officinalis 2 (Lecht Mt.
Tomintour 422m (140S5ft) )

(iv) Trifolium pratense 2, N.B., Ranunculus flammula
2, N.B., Lotus corniculatus 2, N.B. and Tulloch,
Potentilla erecta 3 (Boat of Garten (B.G.) Tulloch
240m (800ft) ), Polygala vulgaris 2, B.G.

(v) Galium saxatile, 2, B.G., Luzula campestris, 3
(Bridge of Brown Tomintour 427m (1424ft) ),

P. erecta 2, B.G. Polygala vulgaris 1, B.G.

(vi) Rubus chamaemonis, 4.

The results of this experiment as regards the dominant
species were similar to the turves referred to in (a)
above. Only one species had, after two years, started
to colonise the shale around, this being Trifolium
pratense. Betula nana, Vaccinium myrtillus, Rubus
chamaemorus, and Vaccinium vitis-idaea survived and
show’slight signs of growth. Galium saxatile, Polygala
vulgaris and Ranunculus flammula appeared to be
dying off.

Turfing is an expensive operation and on the large
scale would be impracticable; however, for small areas
with specific erosion problems it is possible to use
turves as has already been described. The western
turves at Roddymoor closed the foot gap between
them in a season and trapped wind-blown and water-
washed seed uphill and downhill giving visual con-
tinuity in the small scale within three months. The
eastern turves have not closed the gaps, presumably
due to low pH (3.4) and severe nutrient deficiency.
They have, however, remained intact and formed a
useful barrier to rill erosion.

10.7 Experimental herbaceous plantings (see 10.2.5)

These were planted at the Big Waters site in a neutral
shale with relatively good nutrient characteristics in
April 1970. The initial impact was minimal. However,
after a dry summer until August, the results by the
end of August were good, both as to survival and
appearance. The species were as follows and 45 plants
of each were planted in groups:
Species Performance
Alchemilla mollis

Artemisia palmeri

Baptisia australis exaltata
Brunnera macrophylla

Centaurea steenbergii
Cynoglossum sp. X

Epimedium perralderianum
Festuca glauca

Geranium armenum

G. ‘Claridge Druce’

G. grandiflorum alpinum

G. ibericum

G. sylvaticum album

G. wallichianum

Hosta fortunet

H. undulate erromena

Inula hookeri

Lamium galegobdolon florentinum
Lysimachia punctata

Polygonum reynoutria

Salvia superba

Spartina pectinate aurea

Stachys byzantinus

Stipa gigantea

Symphtum caucasicum

Tellima grandiflora purpurea
Tradescantia subaspera montana

All species sur-
vived well into
the first year
after planting,
despite a dry
initial Summer.
Many of them
have already put
on growth

10.8 Conclusions

The most important aspect in vegetating derelict
sites is to treat each site on its own merits. The
following general principles are put forward:

(a) The first essential is to assess the waste material
as a soil forming agent, and to undertake lime and
major nutrient requirement tests, particularly
phosphorus and potassium.

(b) The preparation of the site must ensure adequate
relief from compaction by heavy ripping. If the
site has a history of industry, then the foundations
or other waste should be covered with at least a
915mm (3ft) depth of suitable material so that
ripping could provide a reasonable medium for
plant growth. If possible at the design stage the
incorporation of slopes no greater than 1:8 will ensure
maintenance problems are reduced to a minimum by
allowing agriculture to take place. If steeper slopes
are designed, then access to allow for mechanical
fertilizer spreading should be built into the design.

(c)Removal of stones and preparing the seed bed so that a
favourable environment for plant growth is created is an

essential part of the process. Deep ripping with lime and

112

basic slag, deep cultivation with triple superphosphate,

and harrowing-in of a combined complete fertiliser in a
phosphorus deficient material should help to reduce the
possibilities of plants going into check.

(d) Having assessed the soil forming capabilities of the

(e)

(i)

material and made good any deficiencies of the major
nutrients, suitable seed mixtures can be selected and
applied at the appropriate rates. The more fertile the
material, the nearer to an agricultural rate of sowing. One
and a half times should be adequate, but under adverse
physical conditions twice the rate Would be more
appropriate. Three times the agricultural rate should be
sufficient for the most rapid cover on slopes prone to
erosion or for general use.

Grass and legume species performing successfully for
different uses on the project sites

Agriculture

$24 Perennial Rye Grass
S51 Timothy

S100 White clover

Lolium perenne
Phleum pratense
Trifolium repens

(ii) Forestry and woodland areas

S59 Red Fescue
Black Medock
Creeping Bent
$100 White clover
$123 Red clover

Festuca rubra

Medicago lupulina
Agrostis tenuis
Trifolium repens

T. pratense (seed heads
overwintering give
brown effect apart from
vigour which may tend
to swamp small trans-

plants)
(iii) Recreational areas
S.24 P.R.G. Lolium perenne
E.Z. Mother P.R.G. L. perenne
S.59 Red Fescue F. rubra
S.184 White clover T. repens
(iv) Parkland
S.S0 Timothy Phleum bertolonii

S.100 White clover T. repens

(f) Shrub species which have performed successfully

(i)

Flowers, fruit, erosion protection
Rosa and Rubus spp.

(ii) Spring colour, erosion protection

(iii)

Salix spp.

Erosion protection, winter colour
Cornus spp.

(g) Hedgerow species. Crataegus monogyna, Prunus padus,

(h

P. avium and Sorbus aucuparia all performed well.

) Standard trees. Sorbus aria made the best

contribution. Sorbus aucuparia and Crataegus monogyna
did well. Acer pseudoplatanus, used to replace dead
species which had not be vandalised, did not suffer as
badly from vandalism as the Populus tacamahaca
substituted for the P. canescana at Northbourne Park.
Alnus glutinosa also did well.

(i) Stooled trees. Sorbus aucuparia made the best

contribution, but Populus alba and Betula pendula also
did reasonably well.

(j) Forest transplants. Alnus glutinosa established the best ,
Sorbus aucuparia established satisfactorily and Salix alba
established well in some parts of Roddymoor. Pinus
sylvestris did well, Betula could be regarded as failed.

(k) Nursery stock. Sorbus aucuparia established the best
and Robinid pseudoacacia, Crataegus oxycantha, Prunus
padus, P. cerasifera and Malus communis (Apple stock)
all did well.

(1) Cuttings. Salix spp. established well, Populus less well.
Alnus apical cuttings 460mm (18in) rooted in a shaded
silty area.

It should be emphasised that the tree and shrub species
selected should take account of the individual site
conditions, such as the physical nature of material, exposure,
local climate etc., and also note should be taken of the

local hedgerow and tree species so that the vegetational

cover produced relates to or extends the range of species
in a harmonious manner. This approach will help to
integrate the reclaimed landscape with the surrounding
landscape.

References

Barkley, D.G., Blaser, R.E. and Scmidt, R.E. (1965)
Effect of mulches on microclimate and turf
establishment. Reprint Agron. J. Vol 57 189-192.

Boyce, R. (1965) Grass and Legume species.
Commonwealth Bureau of Pastures & Field Crops,
Hurely, Nr. Maidenhead, Berks.

Breeding, C.H.J. (1961) Crown vetch as an aid to strip
mine reclamation. Reprinted Mining Congress J.

Button, E.F. (1964) Establishing slope vegetation.
Reprinted from Public Works Magazine.

Button, E.F. and Pothurst, K. (1962) Comparison of
mulch material for turf establishment. Reprinted

from J. Soil and Water Conservation. Vol 17,
No 4, 166-169.

113

Chapter 11 Contract procedure

by |.S. Clark

11.1 Introduction

This chapter examines and considers the various aspects of
contracts for land reclamation including forms of contract,
the competitive element, modifications to standard
conditions, specification, bills of quantities and
administration of contracts.

All the schemes executed as part of the research project
were carried out for local authorities receiving government
grant but the procedures examined in this chapter are
considered in broad terms and not restricted to local
authority reclamation schemes.

11.2 Contracts generally

It is as well at the outset to consider the types of contract
procedure and their application to reclamation before
proceeding to examine the specific details of a land
reclamation contract document.

11.2.1 Types of contract

It is convenient to consider contracts under two heads:
(a) Incentive and risk bearing contracts in which the
contractor is awarded the contract either by competition
or negotiation, estimated against the background of
market prices ruling at the time. In this case the
contractor has a high incentive to lower his costs and
thereby increase his profit.

(b) Cost reimbursement contracts in which the
contractor is paid his prime cost plus either a percentage
or a fixed fee for site management, overheads and profit.
Incentive and risk is low in this procedure. A contractor
has no incentive to decrease cost, indeed quite the
reverse with a percentage fee.

A method which falls between the incentive risk-bearing
contract and cost reimbursement contract is the target
cost contract where the contractor is given a partial
incentive for any cost reduction he can make by sharing
this in an agreed proportion with the employer.

The ideal procedure from the point of view of the
employer is one where the contractor has a low element of
risk, together with a financial incentive to reduce cost and
is given the maximum opportunity to do so without
detriment to the standard of workmanship. There is, of
course, a limit to the amount of incentive which can be
provided and the degree to which risk can be eliminated.

11.2.2 Competition

Excluding pure cost reimbursement contracts, all other
types relate to the competitive market for their basis of
pricing. It follows therefore that it is necessary to test
market conditions. In competitive tender contracts the
market is tested for each individual contract, whilst in
negotiated contracts there is a tendency for a
degeneration into a cost reimbursement situation unless
recourse is made from time to time to the competitive

114

market. This does not preclude negotiation of a string of
serial or continuation contracts but it does suggest that
running concurrently with these there should be similar
contracts based on competitive tenders to provide
comparisons of negotiated price with market trends.

11.2.3 Application to reclamation

Having examined the types of procedure and their
relationship in respect of competition generally they can
now be considered specifically in relation to their
application to land reclamation.

Whilst land reclamation has been carried out in this country
for many years, such as restoration of land as part of open
cast mining operations, reclamation as the prime intention
of a contract is relatively new. Simply stated, it is a
combination of landscape and civil engineering contracting
and yet the earthworks encountered are generally of a
magnitude beyond the normal scope of a landscape
contractor and the constructional work in the sense
normally associated with civil engineering contracts does
not exist. It is not surprising therefore that a number of
rates and prices will differ greatly from those normally
encountered in landscape or civil engineering contracts, and
it follows that it is highly desirable to carry out a thorough
test of market conditions by ‘open’ or ‘selective’ tendering
prior to the introduction of other procedures.

Open and selective tender contracts

The ‘open’ tenders, or more properly tenders sought by
public advertisement, have the advantage of providing in a
short time a good indication of the scope, nature and price
range of the market. In the long term they have the
distinct disadvantage of the lack of selectivity and a
tendency to make the market stale by attracting the cut-
price firms, who often execute one contract and
disappear, and discourage more reputable firms.

During the course of the research project it was found that
tenders sought by the ‘open’ procedure usually resulted in
keener tenders than those by the ‘selective’ procedure;
however, it was evident that some of the firms submitting
the lowest tender in the ‘open’ procedure were not ideally
equipped either administratively or with suitable plant to
execute the work satisfactorily. This was not so in those
contracts using the ‘selective’ procedure where careful
consideration could be given to the capabilities of the
firms chosen to tender.

To some extent the ‘select’ tender also provides indications
of market conditions. An indication of the scope and the
nature of the market can be achieved by public advertise-
ment seeking firms interested in this type of project, but
since only a select number will be invited to tender for each
project the price range of the market will not be evident
immediately. Two essential factors emerge from this:
firstly, that a list of competent firms must be made, with
details of their capabilities in terms of size and nature of

TE ar

q

project that each can handle, and secondly, that a
comprehensive list of price levels and market trends must
be kept up to date. In respect of the latter there is possibly
scope for the employment of the central agency to
collect, analyse, and publish such cost information
relating to reclamation schemes.

The adoption of a selected list of approved contractors
from open tender experience does not preclude the
addition of new firms to the list. In fact this is essential
to maintain a healthy and competitive market.

The list of firms so compiled should be in categories
related to plant and management capabilities, or, more
simply stated, in terms of cost. At first sight it might
appear that three categories could be usefully employed,
namely small, medium and large. However, considerable
difficulty has been experienced in the classification of
firms in each category and it is submitted that for
reclamation schemes two categories suffice to meet
normal requirements:

Contracts up to £25,000 in value
Contracts over £25,000 in value

Up to £25,000 suggests the smaller landscape scheme with
more emphasis on minor grading work using relatively
small machines rather than heavy earth moving equipment.
Over £25,000 usually involves the use of these heavier
machines and firms with the organisation and the type

of machines necessary to carry out such works are
invariably capable of executing contracts ranging from
tens to hundreds of thousands of pounds in value.

Within each category the number of firms listed should be
of sufficient number to avoid the necessity of inviting the
same firm to tender for several schemes which could

give one firm more than its fair share. There is also the
danger of price rigging between tenderers if the list is
small.

Great care is required in selecting tenderers from the list
to ensure genuine interest, that they have operatives,

plant and management facilities available for such a
project, that the value and nature of the work is within

the price range and scale of works they normally
undertake and that a sufficient number of firms are
invited to provide an adequate element of competition.
This does not necessarily guarantee the lowest possible
tender, but providing care is taken in selecting the tenderers
it does ensure a competitive and reasonable tender from a
firm known to have the required capabilities and standards
of workmanship. It is suggested that a useful guide to the
number of tenderers can be obtained from the codes of
procedure for selective tendering for the building and

civil engineering industries and for most schemes six or at
the most eight selected firms should provide an adequate
degree of competition.

The lists of approved firms in each category will require
constant revision to take account of new firms entering the
market, existing firms withdrawing or changing from one
category of work to another. The maximum number of
firms in each category need not be fixed but the minimum
should be related to the average number of schemes in each
category sent out to tender each year to ensure the
availability of a different list of firms for each project in a
category during any one year.

It is evident that a three-phase procedure could usefully be
adopted by an organisation contemplating reclamation on

a large scale. The first to establish market conditions by
‘open’ tender; the second to introduce ‘selective’ tendering
once market conditions have been satisfactorily tested and
established; and third to introduce serial or continuation
contracts to reduce contract risk and promote incentive
cost reductions by planned capital investments in plant.

An employer with a major reclamation programme could
well adopt a series of continuation contracts with a number
of selected contractors based on the following procedure:

(a) Selection of contractors The contractors invited to
participate would have to be selected from a carefully
compiled list. Experience of individual contractor’s
performances gained from the open and selective
procedures would greatly assist in this selection.

(b) Scope The number and value of the schemes offered
would have to be sufficient in monetary value and period
of time over which they are to be executed, to provide the
contractor with the necessary incentive. The attractions
must be for the purchase of plant almost specifically for
the schemes and its use over a period of time would greatly
reduce the risk element of the investment in expensive
machinery. This in turn would have a marked effect on
unit rates because plant rates for normal contracting work
contain a large element for lost-working or non-working
time and are therefore inflated to cover this element.

(c) Tender procedure The tender procedure would
require careful consideration. Essentially an element of
competition should be introduced for each series of
contracts, either by inviting selected contractors to
submit a schedule of rates and percentage addition for
on-costs and profits expressed against a specified lump
sum, or alternatively tender for a specific project split
into (a) lump sum for the works (b) lump sum for on-costs,
preliminaries and site management and (c) a lump sum for
head office charges and profit. The sums for (b) and (c)
can then be expressed as a percentage for following
contracts in the series.

(d) Safeguards Safeguards in the form of penalties for
termination of the series would be required in the event of
the chosen contractor not providing an acceptable
standard of performance, in effect the provision of a
‘break’ clause between each contract in a series.

(e) Fluctuations Provision would be required for
fluctuations in rates of wages, cost of materials and all
other costs, taxes etc., varying between contracts in a
series.

(f) Form of contract The form of contract would not
differ greatly from a normal lump sum contract and
existing forms would be readily adaptable.

The above is possibly an over simplified statement of a
possible procedure and other factors would require
consideration, these include: careful programming of
future projects to guarantee contract continuation in the
series; early employment of the contractor's expertise

in design and methods of working, thereby increasing his
incentive to reduce cost; whether limitations are to be put
on the scope of each contract in a series, that is whether
certain sections of the work such as surface treatments
and planting etc., are to be included or excluded from the
contract.

115

‘Package deal’ contracts

All the above procedures are based upon the employer
retaining control of the design either himself or through
professional consultants.

‘Package deal’ contracts, that is where the contractor
assumes responsibility for part or the whole of the

design as well as the construction have been usefully
employed in the building and civil engineering industry
where the employer appoints the contractor to execute a
scheme involving work for which the contractor has
designed and developed a system to perform a given
function. An example of this is industrial building where
the contractor’s design service is an essential part of his
employment. At the present time little if anything would
appear to be gained by adopting such a procedure for
reclamation. Certainly in the case of serial or continuation
contracts the contractor’s expertise from the design point
of view is a factor to be considered but even in these
circumstances loss of the employer’s design control would
be a disadvantage.

11.2.4 Form of contract

The form of contract used for any scheme, whether of a
building or civil engineering nature, has little bearing on
the tender procedures used.

Choice of the form to use ona particular scheme depends
largely on the nature of the work involved. Most of the
contracts executed as part of the research project were of
a civil engineering nature and were eminently suitable for
execution under the I.C.E. Form of Contract. Generally,
schemes predominantly of a bulk earthmoving nature with
associated drainage etc. are best catered for by the I.C.E.
form, since these schemes fall basically into a civil
engineering category and attract civil engineering contractors.
This form of contract, whilst complex and obscure to a
degree that has produced judicial conflict in court actions,
does in practice work reasonably satisfactorily and
preserves a fair balance between employer and contractor.
There is reason to believe that in the not too distant future
a new form of contract will emerge which will, it is hoped,
improve interpretation rather than policy. The tender
documents for one scheme in the project (Egerton
Gardens) were based on the I.L.A. Form of Contract. This
was a small scheme with only minor grading and more
emphasis on soft landscaping. No difficulties were
encountered in the administration of this contract but no
particular advantages were found in the use of the I.L.A.
form.

11.3 Conditions of contract

Since the 1.C.E. Contract is applicable to most reclamation
schemes, only amendments relating to the conditions of
this contract are considered below, although similar
modifications will apply to other forms of contract.
Further, only amendments relating specifically to reclam-
ation are considered since other amendments vary
extensively, depending on the individual organisations or
authority’s normal practice.

It should be noted that in keeping with the normal usage
of terms in the I.C_E. Contract, the word ‘engineer’ is used
to describe the person responsible for the design, direction
and supervision of the works. This function was performed
by a Landscape Architect on schemes executed as part of
the Research Project.

116

11.3.1 Amendments to conditions of |.C.E.
Contract

Clause 24 - Accident or injury to workmen

It is incumbent upon the contractor to indemnify the
employer against all claims for injury to persons other
than arising by an act or default of the employer, his
servant or agent (this incidentally can be construed as
applying to the engineer as agent of the employer).

To draw the contractor’s attention to the specific hazards
in respect of reclamation of pit heaps, it is of assistance

to a contractor when assessing his responsibility to add a
sub clause headed ‘unusual hazards’ in which specific
reference is made to damages from concealed fire or cavities
and explosion risk, abandoned shafts etc. and the
contractor’s obligation to indemnify the employer against
all claims, demands, proceedings, damages, costs etc.

arising from such hazards. It is doubtful whether this in any
way increases the contractor’s responsibility under clause
24 but it does serve to draw his specific attention to the
dangers.

Clause 29 - Interference with traffic and adjoining property
The wording of this clause to some extent conflicts with
clause 22 (c) which limits the liability of the contractor.

It is normal in civil engineering contracts to expand and
develop this clause but in addition, for reclamation schemes,
it is advisable to require the contractor to take all reasonable
steps by watering or otherwise to abate nuisance which

may arise through wind action blowing dry materials from
the working plant in dry ground conditions.

This nuisance has been experienced in those projects close
to residential areas, resulting in complaints from inhabitants.
It is doubtful however whether the above wording is
sufficiently specific since there might be circumstances

in which damage to an adjoining owner’s property or trade
could be severe. In such circumstances more stringent
wording could be adopted, if necessary to a point of
requiring the contractor to suspend work in certain

weather conditions.

Clause 41 - Commencement of work

Unlike many other forms of contract the time for
commencement is not to be found in the form of tender
or form of agreement but is notified to the contractor
after the contract has been let. This is not a satisfactory
arrangement in days of rising prices, particularly in
contracts where weather or seasonal considerations may
affect price. More consideration is given to this question
in section 11.5. A further matter relating to this clause

is that the wording ‘an order in writing’ can be construed under

clause 15, as being effected if served on the site agent,

since it is unlikely that the site agent would be installed at
this time the intention is not clear. An amendment of
wording changing ‘an order’ to a ‘notice’ would appear to
correct this anomaly as a notice under clause 68 (1) ‘shall
be served at the contractor’s principal place of business’.
This applies to any civil engineering contract where a
contractor is not permitted to enter the site until he
receives instructions to proceed.

Clause 42 - Sub-clause (2) wayleaves etc.

Access to a site is of prime importance to the economics
of engineering contracts but the emphasis in this sub-clause
must be on the word ‘special’ which indicates other than
normal access. In fairness to tenderers the access of the

eee eer

site and any restrictions should be fully described in the
specification section of the document.

The effect of this clause is therefore to place upon the
contractor financial responsibility for negotiating private
wayleaves. In respect of reclamation schemes this invariably
relates to adjoining land (very often agricultural) which

the contractor might wish to use for soil dumps. It has been
normal practice in these projects to impose a responsibility
upon the contractor to properly reinstate such areas outside
the site to ‘the satisfaction of the Engineer’, unless the
landowner or his agent issues instructions to the contrary.
It is doubtful whether this clause has any legal validity
unless the employer is the Local Planning Officer who has
jurisdiction over such temporary works. In other cases the
decision will be by private arrangement between contractor
and landowner (as a third party) who in turn might be
controlled by local planning, but in any event would be
outside the authority of the employer or his engineer.

Clause 49 - Definition of ‘period’ of maintenance

This clause defines the ‘period’ as being the period of
maintenance, named in the tender from the date of
completion of the works. The I.C.E. condition is obscure
in its meaning of completion but in this chapter it
undoubtedly means ‘substantial completion’, when under
clause 60 (2) half of the retention monies are released.
This is important since at this stage the risk of damage to
the works passes from the contractor to the employer,
alw ays excluding damage to the works occasioned by the
contractor during the maintenance period whilst
fulfilling his obligation to repair defects.

Bearing in mind that it is the intention that the major
works in reclamation contracts will be carried out by

civil engineering contractors fully conversant and
competent in their field, it is also highly desirable that the
specialised work in respect of surface treatments and
planting should be carried out by a firm fully conversant
with the problems relating thereto and competent in

their field. To ensure that the employer has the necessary
control over this part of the work it is advantageous either
to make it the subject of a PC sum in the bills of quantities
or exclude it completely from the main contract. In
either case special provisions must be made in respect of
maintenance.

Firstly, in the case of a PC sum for surface treatment
seeding and planting, since the execution of this work is
closely related to seasons it naturally follows that
maintenance of the completed works should commence
from the completion of these works. A typical addition
to sub-clause 49 (1) as used on some schemes is as follows:

“The contractor shall be responsible in respect of
maintenance of the earthworks, drainage seeding and
fencing for a period of 12 months from completion of
seeding and in respect of planting for a period of 12
months from completion of the planting.’

It must be admitted that certain confusion has been
created by the word ‘completion’ in this clause by reason
of the obscurity of its meaning in other clauses. The
intention here is ‘the completion of the whole’ of the
seeding or planting as the case may be, rather than
substantial completion, that is nearly but not wholly
com plete. It is suggested that the wording of this clause
should be amended to clarify this point. It should be
remembered that it does not preclude nine out of ten

fields being accepted as complete for purposes of the
maintenance period. The period for the tenth field will
then commence from its seeding completion. Provision
is made for partial completion in clause 48, Maintenance
in the context of this clause is again not correctly used
but this will be examined later.

Secondly in the case of complete exclusion of the seeding
and/or planting work an amendment on the following lines
has been used:

‘The Contractor shall be responsible for the maintenance
of the site for a period of 12 months from the date of
completion of the sowing except that this period shall be
deemed to be completed in the areas of woodland at the
date of commencement of the Council's tree planting
contract, should this occur before the expiration of this
period.’

The comments above in respect of completion apply also to
this clause but in addition it should be noted that the
employer is relinquishing his right to order repair of
defects under clause 49. This again hinges on the use of the
word maintenance. It is suggested that this word is used
incorrectly in this context since the contractor should
remain liable for latent defects, such as subsidence due to
insufficient or incorrect compaction during the earthworks.
The intention should be to relieve the contractor of his
‘additional works’ liability, that is responsibility for grass
cutting, fertilising and other works relating to
establishment of the sward.

In the opening remarks under this clause it was stated that
the risk of damage to the works passes from contractor to
employer; this has an important bearing in relation to
maintenance.

After completion (that is substantial completion ) has been
certified, by the engineer, the contractor’s responsibility,
subject to outstanding works, is reduced to responsibility
for defects only. However it is essential on reclamation
schemes to ensure adequate establishment of the grass and
plants, such as cutting, further fertiliser applications and
weeding. In addition it will be necessary to ensure the
drainage works function correctly by clearing silt from
grit chambers, ditches etc. These are not maintenance works
in relation to defects, but additional works resulting out of
the execution of the contract. It would appear possible
therefore to hold a contractor liable for de-silting ditches
etc. as part of his general obligations before substantial
completion, but thereafter such work can be construed

as being ‘additional works’, or ‘outstanding works’
depending on whether they are referred to in the
specification or bills of quantities. The contingencies of
both outstanding and additional work are provided for in
clause 48 and 49(3) respectively. The methods of
incorporating these items in the tender document are
examined in section 11.4.

Clause 55 and 56 - Quantities and works to be measured
The crucial fact emerging from clause 55 is that the actual
and correct quantities are not those shown in the bills. It
follows therefore that there can be a departure from the
bills of quantities without there being a departure from

the ‘actual and correct quantities of the Works’ that is, such
a departure is not necessarily a variation under clause 51.
Further it is submitted that inclusion of provisional
quantities in the bills serves no more than to emphasise even
more strongly that such quantities are not the ‘actual and

117

correct’ quantities. They are used in bills for work which is
not reasonably predictable in quantity, for example an item
for breaking up hidden foundation. The wording of clause
$6 implies that it is at the engineer's discretion alone
whether any section of the work should be remeasured, but
by reason of the wording of clause 66 which expressly
gives an arbitrator the power to ‘open up, review and revise
any decision of the Engineer’, it is submitted that this

gives the right to either party to demand recalculation if it
is thought a mistake has been made. However, it must also
be pointed out that the engineer’s position is protected
where a contractor fails to present himself upon invitation
to agree calculations by the words ‘should the contractor
not attend’. This would appear to extend protection-even
to arbitration or the courts where power to open up and
review would be limited to valuation and not measurement.
This is essential since alleged quantities of work covered up
cannot be re-checked.

The above, whilst not exclusively pertaining to
reclamation, is important when considering the following
matter under clause 57. Before proceeding to examine
these matters it is of interest to note under clause 56 the
wording *. . . give notice to the contractor. . .” (meaning
to the contractor’s principal place of business) illustrates
the point made in respect of ‘order’ and ‘notice’ in the
examination of clause 41 above. This serves to illustrate
the unaccountable differences and obscurities of wording
in the I.C_E. form and the care required in drafting
amendments.

Clause 57 - Method of measurement
It has been the practice to add the following to this clause:

‘Except that the quantities in the appropriate Bills against
the item referring to the bulk excavation of material from
the waste heap have been calculated from the existing and
the proposed contours shown on the Contract Drawings,
with no allowance made for bulking or compaction. It is not
proposed to re-survey the heaps and the Contractor shall
before tendering satisfy himself as to the adequacy of the
quantities listed against these items.

‘He shall then price and extend this item and the resultant
sum shall constitute a Lump Sum Tender not subject to
measurement and this sum shall not be varied unless the
Engineer instructs a departure from the proposed contours
shown on the Contract Drawings. Even though a Lump Sum
Tender is to be submitted for the bulk excavation work

the Contractor is also required to indicate his unit price
against this item.

‘In the event of any departure as aforesaid the revised
quantity will be agreed and the Sum revised according to
the tendered rate. Such revised sum shall also stand as a
Lump Sum and not be subjected to measurement.’

The intention behind this amendment is self evident although
there is some doubt as to whether the phrase ‘lump sum’ is
used correctly in this context. It might be argued that this
clause runs against the intention of the I.C.E. conditions in
that the quantities are not to be taken as ‘actual and
correct quantities of the Works’. However the tenderer

is given the opportunity and all the necessary information
to check and satisfy himself as to the accuracy of the
quantities at tender stage and should he consider the
quantities incorrect he is at liberty to insert a sum based
upon his own calculations. The disadvantage in such

118

circumstances is that the unit rate would be derived from

his sum and the billed quantities thereby indicating a false
unit rate; for example if a tenderer considers the quantity
in the bills to be high compared with his own, the rate so

derived would be set at an artificially low level.

Should the engineer then find it necessary to order
additional excavation under the terms of the second
paragraph of the amendment the contractor would then

find himself at a distinct and possibly considerable
disadvantage depending on the difference between the
correct and artificial rate. It can be seen therefore that all
possible care should be exercised in the preparation of such
quantities and in the event of a large error being discovered
then serious consideration should be given to the withdrawal
and correction of the tender documents.

Assuming the calculations are correct another complication

can arise in respect of errors in the proposed or original

contour drawings and indeed there is always the imponder-

able question of the amount of bulking or compaction

likely to be experienced. In any event the unit rate will

represent an average price for all the bulk excavation,

that is an average of long and short hauls. Circumstances

could easily arise where it was necessary for the engineer }
to order additional excavation and deposition at the point
of the longest haul. It is submitted under such circumstances
and notwithstanding the third paragraph of the amendment
that a contractor could justify a claim under clause 52 (2)
for additional remuneration over and above tender rate.

This could also apply where the additional quantity is of
such a magnitude that the contractor is entitled to an
extension of the contract under clause 44.

In the past it has been found that the schemes executed with
the amendment to clause 57 incorporated operated
satisfactorily providing all possible care was exercised in the
preparation and checking of the bulk earthworks quantity,
and fair consideration was given to the possibility of rate
amendment in the event of a variation materially affecting
the basis upon which the rate was calculated.

It should be noted that in adopting this amendment
reference should also be made under clause 55 to this
amendment and that certain quantities are deemed to be
‘actual and correct’.

The main disadvantage of leaving the clause unamended is
the physical task of recalculating from site measurement in
the event of the contractor challenging the accuracy of the
quantities and/or drawings. This could mean a re-survey

of the site before and after the earthwork operations with
attendant disadvantages of delays in commencement whilst
the former survey is carried out.

Experience on a number of recent projects, however, has
tended to weigh favour toward deletion of the ‘Lump Sum’
amendment to clause 57. This has arisen mainly through
the problems created by varying compaction factors,
necessitating variations in bulk earthwork quantities.

Additional clauses

It is common practice to include additional clauses in
relation to allowances for travelling expenses, overtime,
fluctuations, site offices and welfare facilities. These

are not essential but they do serve to set out more
explicitly the sometimes oblique references to such matters
in the other conditions of contract.

In relation to care of the works the following clause again
serves to draw the contractor’s attention to more specific
problems which might arise in respect of reclamation:

‘The Contractor shall allow for keeping the trenches,
excavations and works free from water, mud or slop
arising from any source whatsoever during the progress of
the works by pumping, baling or other means of providing
all requisite appliances, etc.

‘During the course of stripping and stacking top and
sub-soil the mass excavation of the materials in the waste
heap and the spreading and regrading of this waste on to
adjoining land, the Contractor shall construct and
operate, until the permanent drainage framework has been
completed, a temporary drainage system of adequate
dimensions as may be necessary to prevent the
accumulation of standing water in ponds and flooding and
damage from taking place in the surrounding communities
and to the contract site itself or other surrounding areas,
from the effects of heavy rainfall or water run off from
snow or spring water.’

The phrases ‘standing water in ponds’ and ‘flooding and
damage from taking place in surrounding communities’
have special significance in relation to local authority’s
schemes, where in addition to the contractor’s
responsibility to take all adequate steps to prevent damage
and pay compensation in event of his failure, the local
authority owes a duty to the public at large to take all
adequate steps to prevent damage. This therefore is
pertinent in respect of the potential dangers of such a site
because of its attractions to small children and also flooding
dangers to nearby properties or lands.

11.4 Specification and bill of quantities

The specification and bill of quantities are complementary
and are therefore best considered together. The specification
should be a comprehensive description of materials and
workmanship without unnecessary or lengthy detailed
descriptions of location or quantities which are self evident
from the drawings and bills of quantities. The bill
descriptions should be concise with sufficient detail to

make the intention clear without repeating information
contained in the specification. All too often too much
reliance is put upon clause 12 (1) ‘sufficiency of tender’ that
all the works described in the specification are included in
the bill rates and sums. The drafting of both specifications
and bills should be such that it makes it clear to tenderers
which items are deemed to be covered in his rates and which
are specifically subject to measured items or provisional
sums. The judicious use of the phrase ‘the Contractor is to
allow in his rates for compliance with the foregoing’ is
often a useful tool where the intention is obscure.

11.4.1 Format of specification and bills of
quantities for reclamation schemes

For most reclamation projects the specification and bills
will require sections for demolition, earthworks, drainage,
surface treatment and fences. In addition the specifications
should contain a ‘description of works’. This section which
lists the drawings as required by clause 1(3) and describes
the scope of the works and access thereto, has an important
function in that both scope and access should be precisely
defined to give full contractual effect to clause 22 ( damage
to persons and property) and clause 42 (possession of the

site). Any information regarding land acquisition should be
included in this section, as this will have a bearing on the
programming of the works, and possession of the site under
clause 42 in respect of delays and expenses incurred from
failure of the employer to give possession. This is examined
in more detail under section 11.5.

The first section of the bills contains the preliminaries, and
provides the contractor with the facility to price separately,
if he should so desire, the cost of complying with the
provisions of the conditions of contract.

It has been the practice in a number of schemes to include
an item in the preliminaries for ‘maintenance’ works in
respect of de-silting ditches etc. As suggested in section 11.3
(clause 49) the use of the word maintenance in this context
is incorrect. In any event it is now considered that such
‘works’ should be contained in the section to which they
relate.

11.4.2 Sections of work in specifications and bills
of quantities

It is not proposed to examine each section in detail but to
consider those aspects which relate to reclamation in
particular.

Demolitions and site clearance ‘Foundations shall be
broken up to a depth of 0.9 m below the finished surface.”

This clause is essential to ensure the finished surface is

free of obstructions to cultivations. It is impossible to assess
the quantity for this item before work commences.
‘Provisional’ quantities in the bills for breaking up brick,
plain and reinforced concrete indicate to the contractor that
there could be a substantial difference between the quantities
stated and the actual quantities. The actual quantity will

be measured and agreed as work proceeds but this will not
constitute a variation under clause 51.

A problem sometimes arises in respect of hidden foundations
within 0.9 m of the surface that do not become apparent
until after substantial completion has been certified. This
invariably means that the contractor has not carried out the
ripping of the surface in accordance with the specification
contained in the surface conditioning and seeding section and
in such cases the additional works required can be construed
as defects under clause 49 (3), payment for which will be

at the rates inserted in the bills against the provisional
quantities. Claims for additional reimbursement, such as the
cost of returning plant to site, are not admissible because

the work arose from the failure of the contractor to

carry out his contractual obligations.

Excavations and earthworks The following general clause is
inserted:

‘The Contractor is deemed to have satisfied himself by
inspection, tests or otherwise as to the exact nature of the
materials to be encountered in the parts of the site where
excavation is to take place and shall include in his price

for excavating any materials likely to be found there such as
shale, stone, bricks, clay, soil, earth, sand, gravel, or other
substances likely to have been associated with coal mining. . .”

This, on the face of it, would appear to be in conflict with:

‘Notwithstanding the general description given previously
for the type of material to be excavated, if hard material
is encountered during these operations in ledges or solid
masses or large detached pieces exceeding 1 m3 normally
or 0.5 m3 in trenches, all of which can only be removed

119

by compressed air tools or similar means this work will be
paid for separately as an extra over item for thatgiven
for normal excavation.’

This is however a valid clause because in any event the
contractor has recourse to clause 12 (2) in respect of
‘physical conditions . . . not reasonably foreseen’ and the
above clause assists in defining the nature of the ‘condition’.
It should be noted the above is entirely separate from the
provision in ‘demolition’ for breaking up foundations for
which no size limits are mentioned. It would appear
unnecessary to apply limits in respect of foundations

as by definition they indicate a mass of brick or concrete
rather than small isolated pieces of rubble. This is not to
imply that the latter is not a problem. Indeed brick and
concrete rubble can at times be a greater problem than
large isolated foundation bases. It is difficult to suggest a
simple solution in terms of specification and quantities
to this particular problem as the solution will vary
depending on the quantity of rubble encountered and
availability of a blanketting material.

It is of coursealways within the power of the engineer
to order such work as is warranted in any particular case.

It is customary to insert the following clause in respect of
red shale encountered in the course of earthworks:

‘Should red burnt colliery shale be encountered in the
mass excavation of the waste heap, which in the opinion
of the Engineer is of sufficient quantity and satisfactory
quality for use during the operations for the final covering
of the respread and regraded black shale, then it shall be
separately excavated as directed, stacked in suitable
positions for use as may be required for the roads or the
working of this material as a top covering to the regraded
black shale.’

This as it stands is a perfectly good clause but it does leave
the contractor in doubt as to whether he is to allow in his
rates for excavating an indefinite quantity of shale
hauling and stacking an indefinite distance. This clause

is improved by the addition of the following:

‘This work will be paid for separately as extra over that for
the mass earthworks.”

Provisional quantities can then be included in the bills of
schedules of additional rates to enable the contractor to
price this item.

It has been practice on these schemes to specify compactions
as follows:

‘The materials in the filling areas shall be deposited in layers
not to exceed 0.3 m in thickness and shall be well compacted
and consolidated by the passage of the earth moving plant
and equipment over the site.’

To a large extent this clause has been framed around the
assumption that the machines used will be tyred scrapers
but it has been found that lack of compaction has occurred
on sites where tracked vehicles alone have been used. There
is no doubt that in the majority of cases the tyred box
scraper is the efficient earthmoving machine for most
reclamation projects, but one hesitates to be too categoric in
a specification on the basis of the maxim ‘specify what but
not how the work is to be done’. Limiting the contractor to
a particular type of machine could possibly saddle the
engineer with a burden of responsibility which in the strict
terms of the contract belongs to the contractor alone.

120

However, a possible solution to this problem is presented
by the addition of the wording *. . . equivalent to that
achieved by a tyred box scraper’. This defines the degree
of compaction without limiting the contractor to the use
of a particular machine.

Drainage The specification and bill items follow those
normally found in civil engineering contracts, but special
mention should be made in respect of works to be

carried out in the maintenance period. These apply
generally to two items, the provision for filling temporary
ditches formed to cope with the initial rug-off problems until
vegetation is established and the provision for the proper
management of the ditch and piped drainage system to
ensure efficient working during the maintenance period. An
item in the specification describing the nature of filling

to the temporary ditches and the time when such filling
should take place, usually as directed by the engineer,

and supported by a measured quantity in the bills would
appear to adequately cover the first item above.

As previously indicated it is preferable to include items in
relation to management of the drainage system in the
drainage section rather than in the preliminaries. The
specification should specifically state the contractor’s
responsibility on the following lines:

‘The Contractor shall undertake during the maintenance
period all necessary work in respect of the clearance of silt
and other obstructions from streams, ditches, pipes, flumes,
chambers and outfalls to maintain the efficient w orking of
the system.

‘In fulfilling this responsibility he shall at regular intervals
(a particular interval could be specified) inspect the system
and organise such work as is necessary.

‘Prices shall include for any additional insurances, use and
maintenance of plant and tools, superintendence and
inspector’s time, overhead charges and profit unless included
elsewhere.’

Alternatively, a provisional sum can be included for this
work to be ordered by the engineer at such times he considers
necessary, and paid for on a daywork basis.

The last paragraph is possibly superfluous in that clause 12
(1) requires the contractor to satisfy himself that ‘rates and
prices . . . cover all obligations . . . for proper maintenance
and completion’. However, it does serve to remind the
contractor that these are additional works rather than
maintenance of defects.

Whilst considering work during the maintenance period, it

is well to mention that it is often necessary to carry out
additional drainage works, that is additional ditches, drains
etc. to ensure the efficient drainage of the site. Requirements
of this nature can of course extend for a time far beyond

the main contract and final completion, but in respect

of the maintenance period it is submitted that the engineer
has power to order such additional essential works.

However such work must be essential to the proper
completion and functioning of the works and, if thought
likely, is best included as provisional quantities or a
provisional sum in the bills.

Major additional works should be made subject to a
separate contract as works done during the maintenance
period do not extend the said period and therefore the
employer has little protection against defects.

Surface treatments, seeding and planting This is possibly
the most difficult section to specify precisely since the
cultivation, lime and fertiliser requirements will depend on
the nature of the surface material. It is necessary to provide
a concise framework for the contractor to price, drawn up
in a form that gives the engineer latitude to amend the
specification to suit site conditions. A loosely worded
specification such as ‘cultivate to a tilth approved by the
engineer’ does little to indicate to the contractor the
precise requirement or give the engineer a basis for
amending the specification. It is preferable to schedule

the engineer's requirements on the following lines:

“Upon completion of liming and spreading topsoil where
applicable the Contractor shall undertake the following
operations over the shale areas in the order shown unless
amended by the Engineer in writing:

Cultivate (heavy 150 mm)

Disc (heavy )

Remove all bricks, stones, wood, metal or other
materials larger than SO mm diameter brought to the
surface during cultivation

*Scrub’ to remove hollows left after 3 above

Disc (light)

Distribute fertiliser (spinner broadcaster) at prescribed
rate (500 kg/ha on red shale, 750 kg/ha on black shale)
Broadcast seed at prescribed rate

Harrow roll

wn~e

on aust

The above is not intended as a recommended treatment for
any particular material since each must be considered
individually for the cultivation likely to provide the
required surface, but it does serve to illustrate a framework
for a contractor to assess accurately the cost of the
operations necessary. It further provides the engineer

with the facility to add, omit or rearrange cultivation
operations as site conditions dictate. The inclusion of a
single cultivation operation in the schedule of rates
provides the necessary framework in assessing the values
of such variations.

Item 3, stone picking, whilst perfectly clear in its intent for
the cultivation of normal soils, does create problems on
reclamation sites. The nature of material encountered,
varying from hard stony shales to fine friable shales, will
have a marked effect on the amount of stone picking
required, and therefore cost. The specification calls for
materials brought to the surface during cultivations to be
removed. This, however, does not include material brought
up to the surface by weather action and erosion.

It is impossible to frame a specification to cover all these
possibilities without imposing an unfair burden upon the
contractor, yet it would be unstaisfactory to cover all such
work by a daywork provision. It is submitted that whilst
this specification is inadequate in scope there is provision
within the conditions of contract clause 52 (2) for an
engineer to vary the rate for additional work, and under
clause 52 (3) to order additional work on a daywork basis.
Further, there is protection for the contractor under clause
12 (2) against adverse physical conditions.

In practice it has been found that conditions of excess stony
material in isolated areas on a site are best overcome by a
blanket layer of more suitable material.

Since lime and fertiliser requirements are not known until
after soil analysis, a provisional sum for the supply of these

materials is inserted in the bills. In schemes where part or
all the land is to be reclaimed for agriculture it has been
customary to include a clause in the specification requiring
the contractor or his supplier to claim lime and fertiliser
subsidies, the net cost of such materials then being charged
to the contract. It appears however that this procedure is
incorrect since under the Agricultural Lime Scheme 1966
and Fertilisers (United Kingdom) Scheme 1969 claims can
only be accepted from occupiers of agricultural land. The
Ministry of Agriculture, Fisheries and Food have stated
the view that under the terms of the Acts, derelict land

is not agricultural until it is restored and as such does not
rank for subsidy.

As for drainage, it is preferable to include items for
management during the maintenance period. The full
description of the requirements for cutting, fertilising etc.
are included in the specification and measured in the bills
of quantities. It has been the practice to describe the bill
item as, ‘Cut and maintain seeded areas all as described
during the maintenance period’. Whilst the intention is clear
the use of the word ‘maintain’ is unfortunate and in fact
incorrect in the context used. This work is not maintenance
as defined in the conditions of contract but is additional
work. It is suggested therefore that the following wording is
preferable:

‘Cut grass and carry out establishment work as described
during the maintenance period.”

The problems in respect of maintenance liability created

by the letting of separate contracts for planting and seeding
has been examined in section 11.3, (clause 49) but from the
experience gained on the larger schemes of this project
there is little doubt that the cultivation, seeding and planting
work are so foreign to the main earthworks and drainage
contract that they are best executed as a completely
separate contract. To avoid overlapping of maintenance
responsibilities, cultivations are best commenced after
completion of the main contractor’s defects period. This
divides the work into neat compartments but does create

a difficulty in respect of the possibility of severe surface
erosion during the main contractor's twelve month
maintenance period. However, if adequate precautions

are taken to reduce erosion by the provision of temporary
cut-off ditches, and it is accepted that a modicum of
erosion repair will be required, there is a great deal to
commend this arrangement. It is also submitted that

the adoption of separate contracts removes the need for a
twelve month maintenance period for the main contract.
Six months would appear to be reasonably adequate to show
up defects in the bulk earthworks and drainage works.

Fences No special provisions are required in the specification
or bills of quantities for this work but some difficulty has
been experienced in respect of obstructions in post holes.

It is impossible to cater for such obstructions in the
specification and should their occurence appear likely

they are best covered by provisional quantities similar

to those included for hidden foundations in the demolitions
and site clearance section.

Schedule of rates These fulfill the normal function of
giving the engineer additional pricing information on
composite items in the bills of quantities which the
engineer might require at some time during the period
of the contract.

121

The main use in reclamation is to provide a breakdown of
the composite items for cultivation in the ‘surface treatment’
section. This intention should be made clear in the documents
since the rates inserted in this section on a number of
schemes have borne little relationship to the composite
items. It has been found that the insertion of unrealistic
rates can be avoided by providing ‘provisional quantities’
against these items for the contractor to price, extend

and carry forward to the main summary. The work thereby
forms part of the tender and as such requires proper
consideration by tenderers.

11.5 Administration

The management of reclamation contracts differs little
from other civil engineering contracts, but certain aspects
are worthy of comment.

11.5.1 Post-contract obligations

Under the I.C.E. Form of Contract obligations, in respect of
production of a programme, securing bond and insurances
are post-contractual obligations of the contractor and not a
condition of the contract coming into being. Further under
this form no date for commencement of the work is
prescribed by the Form of Tender or Form of Agreement.

Programme of works Clause 14 provides for submission of
a programme at the request of the engineer. This clause is
admirable in that it recognises the much higher degree of
interest and control an employer has in engineering as
against building contracts, but unfortunately there is no
sanction or machinery provided for its enforcement other
than in a very serious case, the drastic remedy of determin-
ation under clause 63.

Difficulty in obtaining a programme has been experienced
on a number of the schemes, and has been an impediment
to the engineer in exercising his control and planning
function.

It is submitted that a sufficient sanction could be applied
if the programme had to be supplied, either at tender stage
or before entering the site, or interim payments could be
witheld until the programme is furnished. The first method
has pitfalls in that the contractor is not likely to consider
a detailed programme seriously at this stage; in any

event such a programme would tend to be optimistic
because it is considered at tender stage.

It might appear that the second method is the most

suitable and the programme could be made enforceable by
its inclusion in the form of tender, as an undertaking on the
part of the contractor. However, a severe disadvantage
occurs in the possible delay in commencement since the
employer, by witholding entry, delays commencement,
which could work against his interest as well as that of the
contractor.

The third method has distinct advantages in that a delay

in answering the engineer’s request brings monetary
repercussions. A sub-clause to this effect could be added to
clause 41 of the conditions of contract. The engineer can
request the submission of a programme before ordering
commencement in the normal way but he then has the
necessary machinery to enforce compliance with his
request should the contractor he dilatory.

Guarantee bond The acquisition of an approved bond has
proved to be a problem on a number of the schemes. The

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provision of a bond is not a condition precedent to
commencement and the methods suggested above to
expedite the production of a programme can also be
applied to the bond. In many cases, however, the problem
is not the failure by the contractor in attempting, to
secure a bond, but his failure to find a bondsman. This
mostly arises in ‘open tender’ when there is a large number
of tenders and a big margin between lowest and highest
tender. The position is further aggravated if the lowest
tender is submitted by a relatively small firm with limited
financial resources. This aspect of the problem is largely
removed by adoption of ‘selective tendering’, and is a further
argument in favour of its adoption.

Jnsurances In the case of insurance, in particular third

party insurance, clause 23 (1) clearly defines this obligation
as a condition subsequent to the execution of a contract,
and it is sensible for the employer, or the engineer, on

the employer’s behalf, to satisfy himself that such insurances
are adequate, before work commences.

The provision of insurances has not created any major
problems on schemes in the project, but unlike programme
and bond, it is advisable to ascertain that the type and
terms of the contractor’s insurances are adequate before
work commences. Application of a monetary sanction to
the provision of a programme and bond, is, it is submitted,
adequate to enforce the provision, but in respect of
insurance the risk of damage or injury starts with the
contractor’s first moment on the site. It would appear
prudent therefore to ensure that the contractor’s
insurances, particularly third party insurances, are adequate
before entry is permitted. This should be made clear in the
tender document by a suitable amendment to the
insurance clauses.

Commencement and possession of site As commented in
section 11.4, clause 41 of the conditions of contract
provides for notification of time for commencement after
the contract is let. Unfortunately all too often this

clause is used unfairly by the employer in delaying the issue
of the instruction to proceed.

It has been the practice in the project to endeavour to
indicate the likely starting date, but this has purposely been
loosely worded and more emphasis is placed on an instruc-
tion that ‘tenders are to remain open for acceptance for a
period of three months . . .. This is not satisfactory because
the only reliable information that the contractor can deduce
from this is that commencement could be any time between
the date for submission of tender and three months plus
fourteen days from that date. This is not satisfactory on a
scheme where weather and seasonal considerations play
such a big part and when the cost to a contractor of
reserving plant whilst awaiting this instruction can be
considerable. It must be understood that what is unsatis-
factory is not the length of period, so much as the
uncertainty of a starting date. It would be infinitely

better to state a definite date for commencement, for
example, ‘two months from the date for submission of
tenders’. This would not in any way affect normal
processes of consideration and acceptance of a tender

but it would provide the successful tenderer with
information to plan his plant, staff and management
requirements prior to commencement, and greatly

reduce the risk of plant standing idle.

Clearly the adoption of such a procedure imposes a
responsibility upon the employer to ensure that the site
becomes available for entry at the date specified, and
failure on his part renders him liable under clause 42 (1)
for the contractor’s loss and expenses incurred. This
additional responsibility would not be acceptable to some
employers, but it is suggested that it is fair and reasonable
to accept in the light of the imposed responsibility upon
the contractor to commence within fourteen days and
complete within the time specified. After all, failure on the
contractor’s part in these respects brings forfeiture or
monetary sanctions by way of liquidated damages; should
not the employer have similar responsibilities?

Depending upon the amendments made to enforce the
provision of programme, bond and insurances, any
specified commencement date will be subject to the
requirements of such amendments

11.5.2 Supervision

The supervision of reclamation schemes follows the normal
pattern for any civil engineering project, but it is worthy of
note that these schemes need more site supervision through-
out the contract than most civil schemes of a comparable
size. It has been found that the services of a clerk of

works can be usefully employed under the provision of

clause | (d) to carry out day to day site inspections, tests
and examine materials used and workmanship. However,

it must always be remembered that the use of a clerk of
works in no way relieves the engineer of his duties.

The clerk of works’ duties should, therefore, be clearly
stated and undertsood by all parties at the outset, and it is
suggested that these duties be restricted to the terms stated
in clause 2, that is ‘watch and supervise’ thus ensuring

that the requirements of the specification are fulfilled and
that materials and workmanship conform to description, and
that plant returns, dayworks, site works etc. are properly
recorded and certified.

11.5.3 Financial control

The financial control in respect of remeasurement, variations
and valuation differ little from any other civil engineering
contract. However special care was exercised on all the
project schemes to ensure that the employer was kept
informed of variations in cost and the overall effect on the
contract sum, by submitting financial statements at regular
intervals.

Since the early schemes were executed as pilots for the
many schemes to follow, a careful watch was kept on price
trends to assist in more accurate estimating. The application
of this cost information in estimating cost planning, and
cost control, is examined in detail in Chapter 12.

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Chapter 12 Estimating and cost control

by I.S. Clark

12.1 The relation of estimate to cost plan

Estimating is an essential part of the pre-contract work. It
is upon the proposed design and estimated cost that the
decision is made to proceed to the tender stage of a project
and it is the estimate which provides the basis of cost
control. Comparative cost exercises for alternative designs
or solutions to the design brief form the basis of the cost
plan, culminating in an estimate of cost.

Cost planning is a system which relates design to cost, so
that the solution to the design brief not only provides the
answer in terms of function and appearance but also an
economic solution within a pre-determined cost limit. It
is unrealistic to attempt to set exact pre-determined cost
limits on reclamation schemes since rarely do two projects
have the same problems, but the principles still apply in
terms of reaching an economic solution.

12.2 Estimates for reclamation projects

Estimates for reclamation projects are readily broken down
into the main elemental sections of work to be carried out
on site. These sections also conveniently provide the basic
sub-divisions of the bills of quantities in the tender docu-
ment and thereby provide quick comparison of cost when
tenders are received.

12.2.1 Preliminaries

These we best covered as a proportion of the total estimated
amount, 5% on the smaller projects (£20,000 to £50,000)
down to 2% or less on the larger projects (£100,000 and
over). In most instances, preliminaries, works, site super-
vision, plant etc. are included in the unit rates. The pro-
vision of huts, off site management, notice boards, welfare
facilities for the men are usually adequately covered by the
above percentage additions.

12.2.2 Demolition and site clearance

There is always a certain amount of demolition and site
clearance associated with these projects since the derelict
area usually contains industrial buildings of one sort or
another in various stages of dilapidation. There are no
criteria to apply, each site being taken on its own merits,
but generally the cost of this section is small in comparison
with the total. In addition, it is found that contract rates
for this work are generally at a low level as most of the
material arising from the demolition can be accommodated
on site. The large earthmoving equipment used on these
schemes disposes of the buildings, debris etc. very quickly.

A problem found on the majority of the sites is hidden
concrete and brick foundations. On many schemes, there

is little or no information available to give positions of
bases,culverts, foundations and the like. The first know-
ledge of the existence of such items comes when the Con-
tractor commences work in the area. The breaking up of
these foundations is invariably the only solution, albeit
costly if discovered at this stage of the works. It has become

124

increasingly apparent that every effort should be made to
ascertain the nature of the ground conditions where filling
is not contemplated or where filling is no more than a few
feet thick, and if possible make provision for adequate fill
cover of any areas suspect, also ensure cultivation and
drainage works are not impeded by such items.

Prior knowledge of a difficult area at the estimate stage
enables consideration to be given to alternatives; that is, the
cost of breaking up as against the cost of a design change to
provide a blanket of shale or similar material of a sufficient
depth to obviate the necessity of breaking up. This is an
example of cost planning in relation to design to arrive at a
practical as well as an economic solution.

12.2.3 Earthworks

This section forms the largest part of most reclamation
projects. It comprises stripping and stacking available top
soil and subsequent respreading, bulk earth movement and
grading to proposed contours. From the point of view of
cost this section usually accounts for 50% to 80% of the
total and is, therefore, extremely critical.

Stripping, stacking and replacement of top soil is relatively
easily assessed from the proposal drawings. In practice, it is
found that the depth and location of the respread material
within reasonable limits has only a marginal effect on cost;
quantities are, therefore, assessed on a cubic metre basis.

The bulk earthworks quantity and costing is by far the most

critical. Generally one million cubic metres or more are to

be expected on sites of forty hectares or over (total value

of scheme around £100,000). It is essential on schemes of

this size to carry out accurate earthworks calculations to

ascertain firstly that balance of cut and fill can be achieved

within reasonable limits, without drastically amending the

proposed design, and secondly to provide an excavation

quantity for pricing; a 10% error on a million cubic metre

scheme could represent £5,000 in cost (methods of earth-

work calculation are discussed in Chapter 5.). Having

achieved a satisfactory result in the bulk earthwork cal-

culations, it is then necessary to apply a suitable unit rate

to ascertain the cost. In practice, a tendering contractor

would assess his plant requirements with due regard to site -
conditions, type of material, topography of the site and

plant availability. This, together with his calculated average

time for haulage distance enables him to assess the number

of machines and time required whieh, computed against

his known costs and overheads, results in his total cost. This

is possibly a simplified statement of the Contractor’s pricing
process, but it serves to illustrate the particular difficulty at §
the estimating stage when the type of machine to be used is
not known, although one might make an intelligent assump-

tion. The state of the market whether busy or slack is also :
an important factor. This factor has detectable trends, the

seasonal trend being the most obvious. Contractors’ plant

can be kept fully employed on remunerative work during ;
the drier seasons, such work as motorways, bridges, dams

and civil engineering projects generally. Winter working on

these projects can result in a 50% loss of output or more. fl

The nature of the material often encountered on reclama-
tion schemes is such that all weather working is possible.
They offer, therefore, attractive winter working for a Con-
tractor, where his machines can earn their keep over a period
which he would normally expect to be unremunerative. For
this reason contracts let in late autumn reflect this trend and
the likely date for commencement of a contract must be
taken into account when preparing the estimate.

A further, more subtle, trend occurs through “Contract
experience”. Contyactors adjust their pricing in the light

of experience on similar previous projects. Hitherto few
contractors in this country have had previous knowledge or
experience on the specific difficulties of reclamation work.
The basic advantage to contractors on reclamation schemes,
other than the all weather aspect mentioned above, is quick
turnover. The bulk earthworks on a million cubic metre
scheme - if properly programmed, with suitable machines -
can be executed in six months or less. Any unforeseen con-
tingency delaying this programme can have an adverse effect
on profitability where rates are keen and profit margins are
small. A price difference is often noticeable in the compar-
ison of tenders obtained by way of open and selective pro-
cedures. The former procedure provides the opportunity

for new firms to enter the field and prices on the whole tend
to be keener. Whether the tender is to be ‘open’ or ‘selective’
must be borne in mind when preparing the estimate.

12.2.4 Drainage and services

Each project has its own particular difficulties associated
with the particular land form and requirements for drainage,
water supply and diversion of public services. Costs of pub-
lic service diversions can usually be obtained for estimating
purposes from the public undertaking concerned. Drainage
for these schemes usually follows a conventional pattern of
ditching, tile and piped drains with associated catch pits and
manholes.

The proposed land form will have a considerable bearing on
drainage requirements. The cost implication of alternative
landforms with attendant drainage requirements should be
considered early in the design proposals to arrive at the most
economic solution. In this respect care must be exercised
when considering an open ditch construction against a

piped drain alternative. The open ditch is not necessarily the
cheapest solution when consideration has to be given to
lining the ditch with a concrete flume, gabion mattress or
similar lining to prevent erosion and scour.

Maintenance after completion is essential to keep the drain-
age system in sound working order. Work involved in de-
silting drains and chambers can be considerable in the
twelve months after completion of the scheme during which
time the drainage system requires regular checking and
attention. An allowance of 1% - 2% of the total estimated
drainage cost has generally been found to be adequate.

12.2.5 Surface treatments, seeding and planting

This section comprises cultivation, fertilisation and seeding
of the reclaimed areas and associated land affected, soil
stabilisation treatment of slopes, tree and shrub planting.

The cost level of general cultivations and seeding is much
higher than for normal agricultural work, as would be expec-
ted considering the nature of the soil. A cost allowance of
£150 - £175 per hectare plus £50 - £60 for ripping and
removing rubbish has been generally found to be adequate

for agricultural cultivations and seeding. The rate for cultiv-
ating and seeding areas covered with a good depth of top and
sub-soil will be at the lower figure, working up to the higher
for bare shale areas, Allowance must be made on slopes of
1:6 or 1:5 for heavier seed rates and over 1:5 (i.e. going up
to 1:3) hydromatic seeding and mulching treatments are
often used. The cost of the latter can be anything from £250
to £750 per hectare depending on the area involved and seed
application rates.
Lime and fertiliser treatments vary depending on the
chemical nature of the material. Preliminary analyses of
surface and bore hole samples by the University Soils
Department were a very useful guide at the estimating stage
to assess the likely requirements. The costs of these treat-
ments are best expressed as a provisional sum in the estim-
ate.

Careful consideration should be given to the landform and
surface treatment requirements since the cost of surface
treatment tends to rise as the gradient of slope increases.
Other factors such as drainage and land use requirements
also affect the issue, but it is of interest to note that whilst
a steeper slope increases surface treatment cost, reducing the
slope, however, can produce a disproportionate increase in
excavation cost. In a ‘cut’ situation (that is all excavation
without fill) a finished slope of 1:3, mulched, hydromati-
cally seeded, and forestry planted, will generally show a
saving on a 1:5 slope covered with 0.3m (1 2in) of soil and
seeded for agricultural use. This saving will increase almost
directly in proportion to the height of the slope; thus in the
above example if the saving on a Sm high slope amounts to
£500 per hectare then the saving on a 10m high slope would
be £1,000 per hectare. No account, of course, has been
taken of the establishment and maintenance costs and also
the after value of the land. The maintenance costs on steep-
er slopes are bound to be higher and the monetary return
from the agricultural land could easily make the extra
capital expenditure worthwhile; however, the sums used in
the above example are indicative of the savings which can
be achieved.

Planting varies from forestry planting (for slope stabilisation
and shelter belts on the larger agricultural schemes) to shrub
and tree planting (on smaller parks or public open spaces).
The costing for estimating purposes is much the same for
any landscape project, but special provision is normally
made for ‘establishment’ and after care costs beyond the
normal maintenance period. A sum to the value of 100% of
the total planting cost is inserted for a five year establish-
ment period, although there is no information available as
yet as to whether this amount is representative of the actual
cost.

12.2.6 Fencing

These follow conventional lines of estimating for the types
required, commonly post and wire or post and rail agricul-
tural. Difficulty has been experienced in driving posts in very
stony ground or where remains of foundations are a few

feet below surface. Generally the extra cost of fences erec-
ted on such ground is insignificant for estimating purposes
unless a large proportion of the fencing is so affected.

12.2.7 Roads and paths

These usually fall into the categories of ‘farm roads’ or
public footpath diversions. They are usually of a hardcore
base and gravel or shale surfacing. They present little diffi-

125

culty from the estimating point of view. The basic materials
are generally available on site and costs are low.

12.2.8 Other miscellaneous items

Other items such as contingencies, professional fees, land
acquisitions, administrative costs, aerial and other surveys
ete are included as required.

12.3 Cost control

To exercise the control of cost, it is essential to have a
measure of cost planning from the outset.

12.3.1 Pre-contract cost control

The most important tool of estimating is cost levels and
trends. In the building industry there are large volumes of
information published by the R.I.C.S., other professional
bodies, building and allied trade organisations. This inform-
ation is up-dated monthly or quarterly and takes account of
market trends. labour availability and material cost vari-
ations, and gives information on changes from detailed, item-
ised units to complete buildings of all types. Such inform-
ation is essential for accurate cost forecasting, planning and
estimating.

From the mass of information available, it is possible to
produce reasonably accurate estimates for all types of build-
ing On a square metre or square foot basis, relating type,
design, locality and other factors to known cost analysis, up
dating the information to take account of increased costs
and latest market trends (i.e. if the market is busy, prices
will tend to be high and vice versa).

In the landscape contracting field, and in particular reclam-
ation, the amount of cost information available as yet is
very limited. The Ministry of Agriculture and Fisheries and
the National Association of Agricultural Contractors do
publish, from time to time, cost information and broad

trends in the industry for cultivation, seeding etc. These,
however, have limited application in the reclamation field.
Cost information compiled from reclamation projects,
completed or at present being executed, has enabled us to
build up a limited cost information guide. This, however,
can only be taken as a very rough guide unless extreme care
is exercised in assessing the effects of the quantity compar-
isons of such items as the bulk earthworks, drainage, treat-
ment and general site conditions. In view of the limited
amount of information available it is doubtful whether this
approach at present warrants the effort involved as a far
more reliable guide is obtained from approximate quantities
measured from the preliminary scheme drawings and costed
out, using prices extracted and compounded from the cost
analysis of previous schemes.

Ideally cost control commences at the same time as the
design work when a cost limit is set according to the client’s
brief requirements. This is rarely possible for reclamation
schemes. Preliminary or outline design proposals must be
carried out initially to provide a basis for an outline esti-
mate. From this estimate more detailed work can proceed,
analysing alternative proposals to arrive at the final design
proposals and estimate.

12.3.2 Post-contract cost control

A properly cost planned project should present little
difficulty in the tender and post-contract stage in terms of
costing.

The control of cost during the progress of the work is

equally, if not more, important than the pre-contract |
planning to keep the Engineer and employer fully abreast

of the financial state of the project at all times. Ideally a

running account of all variations should be kept together

with an estimated valuation of other changes and works

remeasured. Collation of these records enables cost fore-

casts to be made at regular intervals.

126

Chapter 13 Visual assessment of

reclaimed landscape

based on the work of J.J. Ffennell and others

13.1 Appreciation of landscape

Clearly one objective of a policy for the reclamation of
derelict land is to improve its appearance, and this objective
has been supported by the level of grants made for reclam-
ation in areas designated for economic growth, the improve-
ment being held to be a factor in attracting new industries.
On the other hand, it is true to say that there are examples
of dereliction for which claims are made about their
aesthetic interest. In fact, it is very difficult, if not imposs-
ible, to measure visual improvement with any accuracy or
in a manner which is universally acceptable. Response to
landscape varies, for example, with the cultural and econ-
omic background of the observer. The middle classes in the
19th century were attracted by the picturesque aspect of
squalor and poverty when portrayed in a painting, but no
such response was made by those who lived and worked in
these conditions. Similarly, persons brought up in areas of
landscape dereliction find it difficult to accept a pit heap
as a form in the landscape, and to dissociate it from all it
represents in social and economic history. An example of
this conflict in response to the appearance of a pit heap,.is
referred to later in this chapter.

Fines (1968) write thus of the many factors that relate to
visual assessment:

“in its relationship to the observer landscape is multi-
dimensional. The total experience whether pleasant or un-
pleasant obtained by the observer is not dependent solely -
or even mainly - upon the response to visual beauty in the
purest sense of the harmony of form, colour and texture in
a single three dimensional pictorial composition, but upon
interplay of sensory, psychological and sequential exper-
iences”’.

Those responsible for the design of the reclaimed landscape
of the various sites of the research project took into
account the generally accepted principles of relating the
proposals to the surrounding landscape and of the location
and arrangement of the different elements with care and
sensitivity. But, in particular, it was considered important
to investigate the results at an early stage in order to
ascertain what particular elements, and arrangements of
them, made the greatest impact upon the observer in the
way of early visual improvement.

13.2 Methods of analysis

Great interest is now being shown in methods of analysis
of landscape in visual terms, and some references are given
at the end of the Chapter. In general, however, the greater
part of the work of visual analysis has been on the analysis
and classification of large areas of rural landscape, whereas
the various sites of the project, and perhaps the majority of
derelict sites, lie in landscapes which are commonly
accepted as of no more than average quality.

13.3 Government policy towards the environment
of the North East

In the paper The North East published in 1963, the Govern-
ment stated the problem of the area to be principally one of
adjustment, and recognised there was a clear need for
special help to shorten the period of adjustment and ease its
difficulties. It was stated that the aim should be to promote
a steady rise in economic activity as the basis for the con-
tinued growth of employment in the region and that “this
action would be directed over a period of years towards an
increase in the level of activity throughout the region as a
whole rather than towards the relief of unemployment in
particular localities”. The reclamation of derelict land and
the reduction of pollution were included in the Govern-
ment’s programme.

The Northern Economic Planning Council (1966) followed
this up by pointing out that the reclamation of derelict land
is an important part of rehabilitating the whole environment
in the region’s old industrial areas. Unemployment cannot
easily be relieved without a new environment, as new
industries are unlikely to move into the old one, and a new
environment cannot be provided without the reclamation of
derelict land.

13.4 Visual results of landscape reclamation

In May 1970, members of the Steering Committee of the
research project looked at four sites which had either been
reclaimed or were in the process of reclamation by the
University. These were Northbourne Park, Big Waters,
Roddymoor and Egerton Gardens. From the observations
made by the members certain conclusions can be drawn.
The surroundings of any site were particularly prominent
in the observations of the members because, if there is
disorganised clutter around a reclamation scheme, the
smoother surfaces of a newly reclaimed site have a strong
impact by contrast (Fig 13.1). In addition, panorainas are
often exposed by the regrading, and these usually
constitute the main visual change and must be taken into
consideration.

13.5 Questionnaire on visual analysis

In January 1970, a simple questionnaire was sent out to
forty-three people living adjacent to the Roddymoor,
Northbourne Park and Egerton Gardens reclamation sites.
In order to eliminate any risk of suggesting answers, the
questionnaire was a postal one; replies were received from
twenty-one people who either lived or worked in these
areas.

13.5.1 Attitudes to the sites before reclamation

All except one person disliked the sites before reclamation,
and the one exception felt indifferent. Everyone disliked

127

the sordid appearance, and about a third also disliked the
dirt, smell, danger and unavailability for productive use. It
had been wondered if people would have a sentimental
association for the sites through having used them as an
adventure playground during their youth, but this was not

So.

13.5.2 Attitudes to the sites during reclamation

Despite the noise of night working, all twenty-one thought
the reclamation worthwhile, even if there was some incon-
venience. There were requests, however, for a cessation of
work between midnight and five in the morning. In about a
quarter of the cases, inconvenience was suffered from dust
and to a lesser degree from dirt, smell, noise and, in one
case only, traffic.

13.5.3 Attitudes to the sites since reclamation

Everyone felt the reclamation was worthwhile and there
was satisfaction that the sites were at last being used for
some worthwhile purpose. The improved appearance was a
strong factor and, to a considerably lesser degree, lack of
dirt, lack of smell, reduction in danger and availability for
use for walking, sitting and playing.

Nine people considered the change in the shape of the land
and heap to be the more important, while nine others
considered the new cover of grass and trees to be the more

important. The remainder said both were equally important.

13.5.4 Suggestions for improvement

People at Roddymoor wanted more footpaths. They said
there had been a few before reclamation which had been
lost, and they felt that now the site was in a condition to be
more available for public use, then more footpaths should
be provided.

The questionnaire explained that there was intensive tree
planting on all three sites and that in most cases the trees
were small and would take some considerable time to make
a show, but eleven people felt there should be even more
trees. In one case, more grass was wanted, while in another
case less grass was wanted.

The new views made a great impact, and nineteen people
felt there was a significant improvement, while one respon-
dent at Roddymoor felt the increase in sunlight to be a
stronger point (Fig 13.2). One said the improvements were
of equal value, but it was interesting to note how very
strongly people preferred the visual improvement to the
overall environmental one.

13.5.5 Questionnaire on visual analysis

1. Did you like or dislike the site before reclamation?

like nil
dislike 20
indifferent ]
2. What did you most dislike about the site before

reclamation?

dirt 8
smell] 5
danger 8
appearance 20
unavailability for use 5
other reasons (please specify) none given

128

‘oe

10.

HE

Did you like the site before reclamation because:
of its sentimental association

of its use as a children’s playground

it was a large area of no activity e.g. industry,

: farming
you thought it looked pleasant
(nil return, see ‘1’)

Do you, on balance, prefer the site since reclamation?

yes 21
no nil
indifferent nil

What do you like most about the site since
reclamation?

lack of dirt 6
lack of smell 4
reduction in danger 5
appearance 21
availability for use (walking, etc.) 6

other factor mentioned: that the site is being used

What do you dislike about the site since
reclamation?

the use of land after reclamation nil
you are no longer allowed to use it 1
its appearance 1

Which do you consider to be more important?
the change in the shape of the land (heap)

the new cover of grass and trees

equal

Nw Oo

Would you like to see:
more trees (the trees are at present very small
and will grow much larger) 11

fewer trees nil
more grass area 1
less grass area 1
any other improvement - please state

more footpaths 2

Do you consider there to have been any significant
improvement in:

the view 19
direct sunlight 1
both 1

Did you suffer any inconvenience during the work
from

dust 6
dirt 4
smell 3
traffic 1
noise 5

Do you think this could have been lessened in any
way, and if so how?

less work between midnight and 5.0 a.m. (night work
is usually excluded from contracts, unless there are
special circumstances)

In spite of temporary nuisance do you now think that

the reclamation was worth while?
yes 21
no nil

13.6 Assessment of individual sites

The observations of members of the Steering Committee and

the answers to the questionnaire have enabled us to make

Fig.13.1 This photograph taken soon after the completion
of the Northbourne Park site illustrates the extent to
which the contrast between poor quality or untidy develop-
ment adjacent to a reclaimed landscape emphasises by
contrast the visual impact of the smooth grades of the
latter.

Fig 13.2 (a & b) Photographs taken before and after
reclamation at the Roddymoor site. The comparison
demonstrates the increase in sunlight and view, which were
improvements favourably commented upon by persons
answering the questionnaire on visual improvement.

the following generalised assessment of individual sites, bear-
ing in mind that either the Contracts had only been comp-
leted a féw months previously or were still in progress.

13.6.1 Roddymoor, Crook, Co. Durham

Roddymoor is now an example of a soothing rural landscape
(Fig 13.3). The harsh points of the pit heap have gone, the
whole site having been moulded gracefully into the rolling
countryside, and it is now virtually impossible to pick out
Roddymoor from the surrounding environment. The
‘feeling’ of the pit heap has also been removed, for example
the houses previously shielded from the low winter sun now
enjoy improved daylight conditions all the year round

129

The site has now been returned to agricultural land for
stock-grazing, with woodland on the steeper slopes. The
agricultural area has been orientated towards the south
where practicable to give a more favourable aspect. The
steeper northerly slope forms one side of the valley and this
asymmetrical form of a ‘one-sided’ valley is a feature
commonly found in this part of Durham.

The planting has not been designed in the block form-
ations usually used for research purposes, which would be
unsightly when overlooked from the surrounding hills.
Instead the trees have been planted in long lines, following
the contours of the land.

Points to be learned from this scheme are that steep banks
are very prominent in the period immediately following
reclamation and that fencing should be in sympathy with
the surrounding countryside as it forms an important
element in the early stages. Harsh fencing lines with neither
trees nor shrubs can spoil the desired natural look, although
their effect can be slightly softened by having a road or
other ‘line’ weaving through the scheme. .Also, the

design of the new land form must take into account the
possible screening of surrounding areas of low visual value
in the landscape, and conversely the exposure to view of
elements like overhead wires that were previously hidden,
which may occur.

13.6.2 Egerton Gardens, Newcastle upon Tyne

The result of the reclamation was described by one
observer as an example of ‘stimulating sequential urban
landscape’ (Fig 13.4). Bold earth moulding was designed to
give something decisive which stands out from its surround-
ings, even if vandalism is so bad that planting and other ele-
ments are partially destroyed.

The southerly aspect provides views over the Tyne valley
and also gives shelter. Planting on the lower slopes when
growth has increased will screen nearer industrial sites in

the valley bottom, and help to stabilise the steep banks. The
site stands out well from Whickham across the valley.

It was noted that the experience on this site indicated the
need for adequate topsoil cover in an urban setting in order
to produce a hard wearing green cover, incidentally needing
a higher standard of maintenance than in a rural area.

13.6.3 Big Waters, Seaton Burn, Northum berland

The site is to be a nature reserve and provide study facilities
for the Northumberland and Durham Naturalists’ Trust. The
mass planting of the trees even at this early stage of growth
is beginning to give the area a feeling of enclosure, and

contrast in scale is emphasised between what can be seen up

to the ridge and the surrounding landscape beyond. This
emphasises the improvement that has been made. The fact
that the scheme includes a large body of water and a stream
is a great visual asset in the early stages of reclamation.

13.6.4 Northbourne Park, Walker, Newcastle upon
Tyne

The site has been developed as a river-orientated park with

space for strolling, informal recreation, and watching, as

well as provision for boats, fishing etc. The design allows for

more intensive use if this is subsequently felt desirable.

The scheme shows that care must be taken in running hard
footpaths and roads along existing terraces or sloping up
between them, as the result can be harsh and aesthetically
unsatisfactory until the planting develops. Such roadways
may be more sympathetic if they are varied in width and
perhaps have bays to take seats here and there.

Care must also be taken not to use too much paving in
prominent positions as this can look out of place if the
reclaimed landscape is not on formal lines.

13.6.5 Percy Pit, Newburn, Newcastle upon Tyne

Plans were drawn up on the basis of a study done by
Hackett and Vyle in 1966, but it has not been possible to
carry them out. The spoil heap on the site had been
recommended for retention as a landscape and industrial
archaeological feature in the Survey of the Tyne Landscape
(Laurie, 1965), but the local inhabitants were not in

favour of retention. The University research team was
asked to appraise the two recommendations, and the find-
ings are reproduced in full:

Fig.13.3 Part of the reclaimed landscape at the Roddymoor
site, which now constitutes a soothing rural landscape
merging into the surrounding countryside.

130

Fig.13.4 The Egerton Gardens site after reclamation.
This was referred to by one observer as constituting a
‘stimulating sequential urban landscape’, standing out
from its surroundings. Such a design policy can be
described as ‘improvement by means of contrast’.

13.6.6 A Report on the alternative schemes for the
redemption of Percy Pit, Lemington, in the
urban district of Newburn, incorporating
recommendations relating to the redemp-
tion of the heap

(a) Terms of reference An appraisal of the schemes has been

requested; they are briefly:

(i) _ the leaving of the shape of the heap as it is, as envisa-
ged in Mr. Laurie’s Survey of the Tyne Landscape.

(ii) | the removal of the top third of the heap and tying into
the existing land form as a spur.

Other possible schemes are:

(iii) minor landform alternatives.

(iv) drastic re-shaping of the heap and surroundings.

The following is an abstract from the Survey

“Large scale tree planting and grassing is required to cover

partially the unsightly surface of the main conical waste

heap of Percy Pit and the Copperas Lane Site, but there

should be no lowering of height with consequent reduction

of scale in the waste heap which is so magnificently in key

with the monumental quality of the power station and the

cooling towers and chimneys, the breadth of the valley and

the height of the surrounding hills. The crests of both

waste heaps and existing hills should be laid out as ‘viewing

areas’.””

(b) Visual appraisal of the heap - and possible effects of
various land form alterations and different types of revege-
tation. Key viewing points at various distances from the
heap were selected, and an assessment of the impact of the
heap was made. The possible effects of various land form
alterations and different types of revegetation were also
considered.

Viewing Point I

DUNSTON (ROAD - A6081)
Approximate distance from heap: 6.4 km (4 miles)

(i) Comments - visual appraisal
The colour of the heap was such that it merged
completely into the landscape.

(ii) The effects of various land form alterations
Land form alterations would have little impact from
this distance.

(iii) Effects of different types of vegetation
Grassing and tree planting would have little impact
from this distance.

Viewing Point 2

WHIC KHAM THORNS (SWALWELL ROAD) (A6081)
PHOTOGRAPH No. 1 (Fig. 13.5)
Approximate distance from heap: 5.23 km (3.25 miles)

(i) Comments - visual appraisal
The heap fitted into the landscape well, forming a
visual stop to the gradually sloping hills, the back-
ground green fields forming a prominent feature. The
heap itself contrasted well with the cooling towers,
partially blackened at their tops.

Fig. 13.5

(ii)

(in)

The effects of various land form alterations

The present shape of the heap forms a pleasant
feature. However, in order that it might be laid out

as a viewing area and for it to be more readily access-
ible, a certain amount of rounding off might be accept-
able. By removing the top third of the heap, the line
of the surrounding hills would be uninterrupted and
the interesting feature lost.

Effects of different types of vegetation

Grassing the heap might emphasise its present shape
in an unfortunate way, bearing in mind the almost
luminescent quality of the background fields.

Tree planting would merge with the existing tree
planting of the background.

Viewing Point 3

STELLA STAITHS
PHOTOGRAPH No. 2 (Fig. 13.6)
Approximate distance from heap: 1.45 km (0.9 miles)

i)

Comments - visual appraisal

The heap does not make as great an impact as from
the previous viewing point, both chimneys and cooling
towers tend to diminish the visual importance of the
heap.

Fig. 13.6

132

(ii) The effects of various land form alterations

By removing the top third, a spur could be formed
which would merge with the surrounding hills. Slight
rounding off would leave the heap as an interesting
feature as envisaged in Mr. Laurie’s report.

(iii) Effects of different types of vegetation

tree planting

Tree planting in front of the heap would merge into
existing tree planting and hedgerow systems.

Viewing Point 4
SWALWELL - RYTON ROAD (A695)

(i) | Comments - visual appraisal
Glimpses of the heap through the trees gave the
appearance of it fitting in with the landscape.

Viewing Point 5

NEAR WYLAM
PHOTOGRAPH No. 3 (Fig.13.7)
Approximate distance from heap: 5.8% km (3.25 miles)

(i) |Comments - visual appraisal
The heap is situated reasonably well in the bowl of
the valley. The distance is such that it almost merges
with the landscape even in its present form.

(ii) The effects of various land form alterations
There is no strong case for the retention of the heap
in its present form or for its reduction in height by
one third to give a spur.

(ii) Effects of different types of vegetation

Tree grouping on the heap might give rise to an
untidy appearance.

Viewing Point 6

NEAR HEDDON (ROAD - A69)
PHOTOGRAPH No. 4 (Fig.13.8)
Approximate distance from heap: 4.7 km (2.9 miles)

(i) | Comments - visual appraisal
This is probably the most significant distant view
point, the heap forming a visual stop to the sloping
land.

Fig. 13.7

Fig. 13.8

(ii) The effects of various land form alterations
By removing the top third and tying the heap in as a
spur, an interesting feature would be lost.

(iii) Effects of different types of vegetation
Tree planting would merge into existing tree planting
and tend to reduce the height of the heap.

Viewing Point 7

NEWBURN ROAD (A608S5)

Approximate distance from heap: 1.2 km - 0.8 km

(0.75 - 0.5 miles)

(i) Comments - visual appraisal
Viewed as one journeys along this road, the heap
‘sank’ into the landscape and made its ‘re-appearance’
at intervals.

Viewing Point 8

NEAR TERRITORIAL HALL’ NEWBURN
PHOTOGRAPH No. 5 (Fig.13.9)
Approximate distance from heap: 0.8 km (0.5 miles)
(i) Comments - visual appraisal
From this view point the heap is not too dominant

(ii) The effects of various land form alterations
Removal of the top third would reduce its impact.

(iii) Effects of different types of vegetation
Tree planting at the base of the heap would have
little impact from this view. Tree planting on the open
space opposite the school adjacent to the Territorial
Hall would reduce the dominance of the pit heap from
this view point.

Viewing Point 9

NEWBURN ROAD (NEAR CHURCH)
PHOTOGRAPH No. 6 (Fig.13.10)
Approximate distance from heap: 0.72 km (0.45 miles)

(i) Comments - visual appraisal
The pit heap is a dominant element in the landscape;
derelict houses appear at the left of the picture and,
in the middle-ground , industrial concems contribute
as much to the air of dereliction as does the heap
itself. Cleaning-up round the base of the heap would
help, but equally as important is the cleaning-up of
dereliction outside the boundary of the site.

(ii) The effects of various land form alterations
A certain amount of removal and rounding of the top
of the heap would make the heap more acceptable
from close to.

(iii) Effects of different .ypes of vegetation
Tree planting at the base of the heap and on adjacent
industrial sites would diminish the impact of the heap
from fairly close to.

Viewing Point 10

NEWBURN (HIGH STREET)

PHOTOGRAPH No. 7 (Fig.13.11)

Approximate distance from heap: 0.48 km (0.3 miles)

(i) Comments - visual appraisal
The heap again dominates the view.

(ii) The effects of various land form alterations
Slight reduction in height and rounding of the heap
should reduce its overwhelming impact on the

residents to an acceptable degree

(iii) Effects of different types of vegetation
Tree planting at the base would also reduce the

133

Fig. 13.11

impact of the heap. Screening of the Walker
buildings would reduce the heap’s impact still
turther.

Viewing Point 11

NEWBURN (TYNE VIEW)

PHOTOGRAPH No. 8 (Fig.13.12)

Approximate distance from heap: 0.96 km (0.6 miles)

(i) Comments - visual appraisal
The view is dominated by the heap and part of the
Tyne Valley is obscured by it.

(ii) The effects of various land form alterations
Removal of the top third and tying in with the
surrounding land form is a solution which would
reduce the impact of the heap from this view point,
but at the same time would remove a feature of a
wider landscape setting. Rounding of the heap keep-
ing the original form would help to reduce the
impact.

(iii) Effects of different types of vegetation
Tree planting at the base of the heap would also
help to reduce the heap’s dominance.

Viewing Point 12

NEWBURN (LLOYD STREET)
PHOTOGRAPH No. 9 (Fig.13.13)
Approximate distance from heap: 0.32 km (0.2 miles)

Fig. 13.13

134

Fig. 13.12

(i)

(ii)

Comments - visual appraisal

The heap, although a dominant feature, appears to
be more acceptable in its setting than from the
previous view point.

Effects of different types of vegetation

Tree planting round the base of the heap would help
to reduce its impact.

Viewing Point 13

LEMINGTON (UNION HALL ROAD)
Approximate distance from heap: 0.96 km (0.6 miles)

(i)

(ii)

Comments - visual appraisal
The impact of the heap was not too overpowering.

The effects of various land form alterations

The retention of the heap in its present form would
be acceptable from this view point. Reduction in
height by one third and tying into the surrounding
land form as a spur would be equally

acceptable.

Summary recommendations: Bearing in mind the

several matters considered in the above, our

recommendation is that the heap should be :

(i) rounded off at the top (as shown in Scheme 3)

(ii) kept largely unplanted and ungrassed, particul-
arly on the upper slopes,

(iii) tree planting around the base and if possible
outside the site boundary.

(iv) ancillary earthworks around the base towards
the site boundary.

We make one qualification to the above recommend-
ation that we will wish to investigate methods of
holding fine dust particles where the heap is not to
be grassed.

13.7 Conclusions

Landscape can be contrived or uncontrived, and contrived
landscape can fall into two classes - soothing or stimulating.
The experience which relates from landscape depends upon
the sensory, sequential and psychological experience, and
the latter need not always be constant.

An environmental image, or landscape, is not experienced
on its own, but in relation to the context in which it
appears, whatever has happened immediately before, and
even in relation to past memories, This was particularly
important at all the sites, and Roddymoor and Egerton
Gardens are good examples of it.

The replies to the questionnaire showed the interest taken
in the reclamation of landscape by people either living or
working in the vicinity, and their deep appreciation of
their environment is shown in the satisfaction they have
indicated that the land is now being used for something
worthwhile. The continuing Government policy of adjust-
ment to a better environment is appreciated, but people
frequently express the wish that the programme would
move quicker.

13.7.1 Elements and effects giving visual impact

(a) In the early stages of a project, maintenance of
clearly defined and closely mown areas, e.g. the flat
terraces at St. Anthony’s with other areas uncut,
gives emphasis to the land form of a reclamation
scheme.

(b) Footpaths are especially important as their appear-
ance is very dominant, particularly when the reclaimed
landscape is young and with little vegetation.

(c) Terracing effects give visual interest to slopes which
may otherwise be reticent in a view.

(d) Low walls help in the early stages to give interest.

(e) If there is disorganised clutter around a reclamation
scheme, smooth surfaces of a newly reclaimed site
have a strong impact by virtue of contrast.

(f) Terraces built on a curve emphasise the terrace effect.

(g) Standard trees of large size (as at Big Waters) show up
quite prominently against the bare shale soil, but
might be ‘lost’ against grass.

(h) Deep cut streams are prominent and add much
interest to the early barren stages of reclamation - as
the landscape develops, their impact will be less.

(i) One large level platform (cf. Egerton Gardens) does
help to emphasise the modelled landforms elsewhere
on the site.

(j) The sharp angle between the slope and the plateau
(Roddymoor) clarifies the modelling, particularly
when the site is in a young state.

(k) A dense growth of clover adds variety to the usual
cover of grass over a project.

(1) The surrounding countryside can be dramatised by
the new landform design.

(m) The exposure of panoramic views constitutes the
main visual change on many sites, and the effect of
regrading to achieve this, with the screening of
undesirable views, should be taken into consideration.

References

Appleyard, D., Lynch, K. and Meyer, M. (1966) The
View from the Road, M.1.T. Press, Cambridge,
Massachusetts, U.S.A. 2-18.

Branches, D.M. (1969) Critiques of K.D. Fines: Landscape
Evaluation. A research project in East Sussex.
Regional Studies. Vol. 3, No. 1. 91-92.

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