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THE
WORK OF THE ROYAL ENGINEERS
IN THE
EUROPEAN WAR, 1914–19.
WORK IN THE FIELD UNDER THE ENGINEER-
IN-CHIEF, B.E.F.
_2^
GEOLOGICAL WORK ON THE WESTERN FRONT.
PUBLISHED BY THE SECRETARY,
INSTITUTION OF ROYAL ENGINEERS, CHATHAM.
CHATHAM :
W. & J. MACKAY & CO., LIMITED
I 922.
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23.
CONTENTS.
Introduction
CHAPTER I. WATER-SUPPLY.
General Summary
Preparation of Maps º
Selection of Sites for Boreholes
Extraction of Water from Thanet Sands
Card Index of Bores
Curves of Marl. Surface
CHAPTER II. MINING, FIELD POSITIONS, ETC.
Mining in regard to Water Level • -
Determination of Chalk Underground “Water Table"
Relation of Military Mining to Geological Structure
Test Bores for Subway at Nieuport º º
Special Plant for Thick Beds of Water-bearing Sand
Geological Report on Country N. and E. of Passchendaele
Ridge - e - º e º e e
Geological Maps of Areas for Dug-outs in Flanders and
in N. France © e - tº
Crushing of Dug-out Timbers in Ypresian Clay
Souterrains e - e - e -
Ventilation and Drainage of Dug-outs and Souterrains
Tank Maps
Foundations
CHAPTER III. DESCRIPTION AND USE OF BORING PLANTS FOR
GEOLOGICAL TEST BOREs.
Geological Boring Sets
Modified “Acme " Boring Set
The “Wombat" Boring Machine
Earth Augers -
Bores for listening purposes
PAGE
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CONTENTS.
CHAPTER IV. WINNING OF RAW MATERIALS.
Road Metal g - e
Sand and Aggregate for Concrete
Coal Mines. º -> e e e - e
Report on Aggregate used in German “Pill-boxes '' on the
Western Front .
CHAPTER V. GEOLOGICAL ESTABLISHMENTS.
Geologists in the German Army
Geologists in the American Army e e - -
Suggested Geological Establishment for the British Army
PAGE:
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Descrip- No. or
tion. letter.
Plate
Plate
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Figure
Figure
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Figure
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s
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Figure
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Figure
Figure
Figure
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Figure
Figure
I.
II.
III.
IV.
V.
VI
vii.
5
II
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LIST OF ILLUSTRATIONS.
Referred to
Subject.
Geological Section along Front Line Trenches from
Nieuport to the Somme
Ditto - e - * º e e º e
Geological Section from near St. Quentin to the Forêt
de Gobain - e º - & º
Geological Map of Wytschaete I/IO,Ooo . - º
Geological Section of Wytschaete strata classified for
dug-out purposes e * - & - g
Details for Geological Test Boring Sets . º º
Improvements to “Acme ’’. Boring Machine for Boring
in Chalk - - e - º - e
(Photo.) Red Dragon Crater, Givenchy-lez-la-Bassée .
Geological Section from Givenchy to Cuinchy, showing
Mining Conditions º - - e - º
Relation between seasonal variation in level of under-
ground surface of water in chalk, and local percolated
rainfall º - º e • & - *
Section from Givenchy-lez-la-Bassée to Vimy Ridge,
showing seasonal variation of underground water in
the chalk - - - - e - -
Sketch showing variation of chalk water-level, Loos, to
Canal d’Aire near Givenchy-lez-la-Bassée. Sketch
showing variation in water capacity of the three chief
types of chalk on the Western Front -> e
Section showing Geological Structure in the mining
operations between Vimy Ridge and “ The Pimple '' .
(Photo.) “Wombat "Blow near Chassery Crater, Vimy
Ridge e - º - - e - º
Section showing mining Operations under old river
channel between Ontario Farm and Boylès Farm,
near foot of Messines Ridge . e e e
(Photo.) Railway Cutting at Hill 60, Ypres Salient
Geological Section through craters, Hill 60 to Ploeg-
Steert . e - º -
(Photo.) Crater at Ontario Farm º
(Photo.) Main Crater, Hill 60, Ypres Salient º
Section across Yser Canal at Nieuport, showing method
of boring through quicksands with a water jet.
Section showing faults at Scherpenberg - e
Map showing positions of Chief subterranean excavations
(“Souterrains ") in Northern France º e
(Photo.) Tanks bogged in mud, “Clapham Junction,”
Ypres Salient - º - tº e e
(Photo.) Sarsen Stone (Quartzitic Concretion out of
Thanet Sand), The Pimple at N. end of Vimy Ridge
Specimen of Water-Supply Maps I/Ioo,ooo part of
Namur Sheet - e - - o Q º
Section across Vimy Ridge at La Folie Farm -
On page
37,
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38
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33,
43,
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Figure
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INTRODUCTION.
No military geological establishment existed in the British Army
at the beginning of the War.
At a very early stage the need for expert geological advice in regard
to water supply became apparent, and the Chief Engineer (later Engineer-
in-Chief), British Expeditionary Force, applied for the services of a
competent geologist. On the nomination of the Director of the
Geological Survey of England, Lieut. W. B. R. King, Royal Welsh
Fusiliers (now Capt. W. B. R. King, O.B.E.), was appointed in April,
I915, and at first worked at the War Office under the Director of
Fortifications and Works. In June he joined the Staff of the Chief
Engineer in France, under whom he continued to work throughout the
War.
The earliest work in England consisted of studying the available
information on Belgium and Northern France, particularly in relation
to borings, and was mostly done at the Geological Survey and Museum,
28, Jermyn Street. Assistance was also given by the Director of the
Geological Survey, who was engaged upon a report for the War Office
on “Geological Conditions affecting the available sources of water in
Belgium and the North of France.”
A geological map of Belgium, Scale I/I60,000, was prepared from the
I/40,000 Belgian maps in possession of the Geological Survey, and was
printed at Southampton—5 sheets (hand-coloured).
The entire resources of the Geological Survey and Museum were
always at the disposal of the military geologists, and the whole-hearted
co-operation of the Director proved invaluable.
Much useful information was obtained at this time from Professor
Stainier of Ghent.
Valuable advice and assistance were later on given by Dr. Imbeaux,
of Nancy, Professor Ch. Barrois and M. P. Pruvost, of the University
of Lille, and Professor A. Renier, of Brussels.
In May, IQI6, the Australian Mining Corps, organized as a battalion
for Gallipoli (but too late for active operations there), arrived on the
Western Front. Major T. W. E. David (now Lieut.-Col. Sir T. W.
Edgeworth David, K.B.E., C.M.G., D.S.O.), Professor of Geology,
University of Sydney, accompanied it, and up till 25th September,
I916, acted as Geological Adviser to the Controllers of Mines of the
First, Second and Third Armies. After this, he was transferred to the
Inspector of Mines Office, G.H.Q., where he became general Geological
Adviser on matters connected with military mining. A considerable
amount of testing of the ground was carried out with a Special light
boring plant presented to the Mining Corps by Sir Samuel Hordern, of
viii. INTRODUCTION .
Sydney, the immediate supervision of this work being placed under
Lieut. Loftus Hills, Assistant Government Geologist of Tasmania, of
the 2nd Australian Mining Corps, from 25th September, 1916 until the
end of the War. In the aggregate, some 35,000 feet of test bores, for
dug-outs, etc., were made under his direction, largely in front-line
positions.
On I7th September, IQ18, Lieut. Hills was transferred to the Inspector
of Mines Office, G.H.Q., and a few weeks later two more Australian
Tunnelling Co. Officers were lent to the Geological Staff at G.H.Q., in
Order to Cope with the number of fresh geological maps required by the
rapidly advancing armies. Thus, at the date of the signing of the
Armistice, IIth November, IQI8, there were five geologists at G.H.Q.,
whereas from November, IQI6, to September, IQ18, there were only
two at G.H.Q., and one at the H.Q. of the Australian Electrical and
Mechanical Mining and Boring Company; while from April, 1915, until
May, IQI6, there was one geologist only for all the British Forces on
the Western Front.
The whole of the information in the following chapters has been
supplied by Professor Sir T. W. Edgeworth David and Capt. King.
THE WORK OF THE ROYAL ENGINEERS IN THE
EUROPEAN WAR, 1914–1919.
GEOLOGICAL WORK ON THE WESTERN FRONT.—
WATER-SUPPLY.
CHAPTER I.
I. GENERAL SUMMARY.
The chief part of the earlier work consisted of Compiling water
supply maps of those areas of Northern France and Belgium Occupied
by the enemy. The scheme was to show on maps the pre-war
civilian sources of supply, so as to give Some indication as to the
natural resources of the area. The information was arranged on
maps I/IOO,OOO scale, which were printed at Southampton.
Maps were also drawn on purely theoretical grounds of much of
the chalk area of the Scarpe and Somme to give Some indication
of the depth to water.
During the period just prior to, and all the time since, the first
battle of the Somme, boring had become the chief method of obtaining
Supplies of water in the chalk plateau areas. Personal touch was
more or less maintained with the Water Supply Officers of the Armies,
but the area was too large to enable each site to be inspected before
boring started, and only the general geological lines could be given
to the Water Supply Officers.
During the later Stages of the War, maps on I/250,000 scale were
prepared for the greater part of Belgium and Northern France,
dividing the Country up into areas where the water supply conditions
were similar, and short notes were compiled with the help of the
I.R.E.M. at G.H.Q., giving a general idea of the conditions and type
of plant and machinery required in each area.
A card index of all bores made by the British Armies was also kept
up to date.
Sites for bores, etc., were also visited in the L. of C. areas, the central
group of the Canadian Forestry Corps, and in the Nancy area where
the aerodromes of the Independent Air Force, R.A.F., were needing
Supplies of water. In this latter area much useful information was
supplied by the Chief Geologist to the American Expeditionary
Forces, and by the Engineer-in-Chief, Ponts et Chaussées, and the
Director of Municipal Service at Nancy.
2. PREPARATION OF MAPS.
At the time of the arrival in France of the first military geologist
information was being Collected regarding the conditions of water
9
IO
supply in the area in front of our line. This was to enable plans to
be formulated for dealing with the problem of supply of water to
troops in case of an advance. Such information as could be found
was being entered on maps of I/IOO,000 scale. This work was
carried on for the whole of Belgium and invaded territory of Northern
France.
It was difficult to obtain up-to-date and accurate statistics on the
actual Conditions of town supplies. The supplies for villages in
agricultural districts are not likely to change much, but in towns
where water is supplied by a water company the machinery is
Constantly being changed to meet larger demands, and the pipe-line
System is always growing. It results, therefore, that records ten to
fifteen years old are liable to be gravely out of date. The results
Obtained, however, were such that some idea of the state of the
water Supply of an area could be arrived at, and this was of use in
making plans for an advance through the country.
The type of information collected and entered on the maps is
shown on Fig. I8, which is a portion taken from the Namur Water
Supply Map. These maps show the actual site of springs and their
daily yield, location of pipe-lines and adits for collecting water,
pumping stations with daily supply, reservoirs with particulars as to
capacity, sites of boreholes with yield and depth, number of wells per
Commune with range of depth where possible, and whether the
supplies were sufficient for the needs of the civil population in peace
time, etc.
All available information was collected together and arranged on
maps 1/100,000 scale. The work needed considerable judgment in
order to avoid confusion on the maps.
In 1915 a map was prepared of the ground in front of Our lines as
far as Brussels, to show in a general sort of way where water Could be
obtained in great abundance, where a medium Supply could be
expected, and where it would be scarce. The map was coloured in
three shades, the deeper shade being the area where most water was
to be expected. On this map also an attempt to depict the quality
of the water was made by having red for poor quality, purple for
medium, and blue for good quality water. Thus there were nine
different types of water depicted —
Good but scarce.
Medium quality but Scarce.
Bad and Scarce.
Good and medium quantity.
Medium in quantity and quality.
Bad quality but of fair quantity.
Good and abundant.
Abundant but only of medium quality.
Abundant but bad.
II
This map was printed on the scale of I/250,000, although the work
was done on maps of 1/100,000 scale. As none of the ground could be
visited, the lines had to be drawn from the evidence of the Contours
taken in conjunction with the geological structure of the Country,
and any notes regarding the abundance or Scarcity of the village
supplies which were available. The map was required by a certain
date, but if more time had been available, a more accurate result
could probably have been obtained. It was frequently a question
of personal interpretation as to the category to which an area should
belong. The final result was more of use as a general indication of
the difficulty or ease with which a supply of water could be obtained
for troops, in the case of existing supplies having been destroyed by
the enemy, than as an accurate detailed statement of Conditions.
As an example, it may be said that this map was of use in
emphasizing the need for additional water Sterilizing plants and
lorries in the event of an advance towards Ghent, as this area was
shown as having water of bad quality and frequently only in Small
quantities insufficient for troops during summer months.
A map of this nature, prepared on the site during the dry Summer
months, would be of great value in drawing up the requirements of
an Army which might need to occupy the area at Some future period.
During the battle of the Somme, and afterwards, it was frequently
of use to have some idea as to the depth in the chalk at which water
might be expected when troops arrived at any spot formerly in
enemy occupation.
To give this information it was necessary to predict the shape of
the water table (i.e., the surface up to which the chalk is saturated
with water). This was arrived at by drawing cross-sections of the
Country, and, from the Surface configuration, estimating the level up
to which the chalk would be saturated. The sections thus obtained
were plotted, and contour lines joining similar heights were
drawn. The contour lines were drawn at five-metre intervals
and printed on tracing cloth with the grid lines and letters of the
I/40,000 map. This method enabled the tracing to be laid over a
contoured I/40,000 map, and the difference between the surface
altitude, as taken from the contours, and the altitude of the “water
table,” as taken from the tracing, gave a figure in metres which was
the thickness of dry strata before water could be reached. There
were, however, several factors which made the results extremely
general and frequently very inaccurate. Among them was the purely
theoretical nature of the method adopted, which, while giving a
result probably fairly accurate in general principle, was frequently in
error in respect to degree. Secondly, no account was taken of annual
variation of the water level, and, thirdly, the surface contours of
much of the area were liable to considerable error, which, although
not having any great effect on the “water table " contours, intro-
I2
duced grave errors when arriving at the depth to water by subtracting
the "water table "levels from those given by the surface contours.
As the area which was occupied by troops was so large, it was
impossible to visit the sites for all bore-holes before work started.
It was therefore necessary to give such information as was available
in a condensed form which could be taken in at a glance. With this
aim in view a series of maps was prepared which divided the ground
into areas within which the conditions for boring were similar. To
take an example —
The ground near Bethune and Lens divided into areas—
I. Chalk yielding 6,000–10,000 g.p.h. from bore-holes with air lift.
2. Chalk thin and clayey—bore-holes no good—surface springs to
be used.
3. Doubtful area—before boring consult a geologist.
4. Artesian chalk-water area—good for boring.
5. "Blue " Clay area—only small supplies from the “Green "
Sand.
In this way the Army Water Supply Officers and others could see
at a glance in most cases whether a locality would be a good one for
a bore-hole or not.
The first of these maps dealt with ground within our own lines,
but they were gradually extended to take in enemy territory. Maps
of this type, with explanatory notes, were found to be one of the
most Convenient methods of sending information out to the troops,
for in this way a general idea of the country ahead is given without
the necessity of reading a large amount of printed matter. Similar
maps and notes were prepared for Intelligence Reports on Eastern
Belgium shortly before the Armistice.
From time to time geological sections, with a short descriptive note
Of two or three pages, were prepared and sent to Armies to illustrate
the structure either of the area occupied by the troops, or to show any
points of special interest in the area ahead. An example of One of
these sections is given in Fig. Ig.
3. SELECTION OF SITES FOR BORE-HOLES.
(a) In Army Areas. A very large percentage of the Army areas
where boring was the chief method of supply was formed of beds
of Upper Chalk (Senonian). These beds usually contained flints,
particularly in the lower portions. Below the Upper Chalk came
some more beds of chalk with flints, which frequently contained a
certain amount of phosphatic material, and various beds of hard
nodular chalk. The fossil contents of these beds, locally known as
“Tun,” have led the French geologists to group them with the
Middle or Turonian Chalk. The main thickness of the Middle and
Lower Chalk is of a marly character, particularly in the eastern
I3
portions of the area. These beds may be grouped together, from a
water supply point of view, as Chalk Marls. The chalk marls are
practically impervious to water and hold up the water which is
circulating in the fissures of the overlying chalk. It results, therefore,
that, as the surface of the marls nears the surface of the “Water
table,” the thickness of water-bearing chalk is reduced until the
surface of the marls comes to actually coincide with, or reach higher
than, the normal “water table.” When this condition is reached
the water is found only in fissures in the harder beds of the marls,
and a bore-hole may easily miss the fissures and so fail to obtain any
quantity of water. These conditions were found on the high ground
of the Vimy Ridge (see Fig. 19), and accounted for the failure of the
bore-holes put down near Roclincourt and Gouy Servins.
The majority of the sites for bore-holes were chosen more from
military than geological considerations. Amongst the chief qualifi-
cations for a good site, from the military point of view, was ability
to deliver the water by means of an air-lift pump into a tank formed
of canvas placed on the ground, which in turn would gravitate to
water-cart filling points, etc. It was found that 6-in. bore-holes
placed in or near the bottom of a dry valley would yield 8,000 to
I2,000 gallons per hour, according to the depth at which water was
found below the surface. When it was important to obtain a good
supply in the shortest space of time, bores were sited in the valley
bottoms, and when so sited in areas where there was a thickness of
50 ft. or more of good water-bearing chalk, the results were always
satisfactory. As the urgency of demand for water became less, new
holes were frequently made at points further up the valleys, or even
on the plateau top. It was found that, provided the bore was not
on the actual Summit, in most cases a fairly good yield was obtained,
the actual volume depending largely on the depth to water-level.
As a rule, however, where bores were placed on the actual summit of
the plateau, the yield was Small ; as examples of this—Gurlu Wood,
Fressenneville and Pozières may be quoted.
The bore at Saulty, On the top of the plateau, was also a failure, but
this was probably due to the fact that here the chalk marls were
near the surface (See p. 21).
As a rule the yield of a bore could be fairly accurately predicted
and, provided it was not on the actual Summit of the plateau and
that there was sufficient thickness of saturated water-bearing chalk,
the results were satisfactory, i.e., 5,000 gallons per hour, or more, per
6-in. bore.
In order to arrive at Some estimate of the thickness of the Saturated
water-bearing Chalk, a map of the Surface of the chalk marls was
prepared and sent to the Army Water Supply Officers concerned.
Besides these bores in the chalk of Picardy and Artois a certain
number were made by the Armies situated in Flanders. In this
I4
area the only water-bearing horizon is that of the Landenian or
Thanet sands, which is found beneath the Ypresian or London clay
at a depth of 200 ft. to 400 ft. below the surface. Curves of the base
of the Ypresian clay were drawn, from which the depth to the sands
could be estimated. The yield from these bores, however, was
always small, and there was constant trouble owing to the fine sand
choking the bores. Various methods were tried to overcome this
difficulty but seldom with much success (see para. 4).
Some attempts were made to obtain water from the chalk which
underlies the Landenian in Flanders, but this was against the advice
of the geologists, since it was known that here the chalk was thin and
of a hard marly nature, being practically impervious to water. The
results were what might have been expected, and the bores were
abandoned.
(b) L. of C. Area.—The majority of the L. of C. area was chalk
Similar to that of the Army areas, and the problem was similar, but
Several bores were made in the Jurassic rocks of the Boulonnais. In
the neighbourhood of Boulogne and Wimereux the strata belong to
the Kimmeridgian Overlying Corallian and Oxfordian. The water-
bearing horizons are :—
(i) A bed of sand and soft sandstone in the middle of the
Kimmeridgian (Astartian), and
(ii) In certain limestone beds in the Corallian.
This latter is extremely variable both in thickness and water-
bearing qualities. It resulted that the bores which were made into
the sands yielded good supplies, but while a bore in the valley of the
Liane yielded an excellent supply from the Corallian limestones, a
bore near Boulogne proved that the limestone had entirely thinned
out, and the bore ended at a depth of 725 ft. Still in blue clay, which
probably belonged to the Oxfordian. In another bore near Amble-
teuse a thickness of 40 ft. of Oolitic limestone of Corallian age was
passed through, but this yielded no water, while beds of the same
age within a mile or so yielded over 5,000 gallons per hour.
(c) Aerodromes of Independent Air Force, R.A.F.—The aerodromes
in Nancy area and the depôt at Courban needed supplies of water for
the camps. The majority of the aerodromes were situated on the
flat, slightly undulating, ground formed by the Lower Lias limestones.
The limestones themselves gave rise to Small Springs, but the quality
of this water was not good, and they were liable to almost dry up
during the summer months. Another source of supply was available
in most cases from the Infra-Lias or Rhaetic Sandstones. They
were reached either by borings or by wells in the valleys, and yielded
good water, but not always in large volumes. Two aerodromes
were situated on the Bunter sandstones of the Trias, and a boring on
one of these yielded a good Supply.
I5
Much useful information was obtained from Dr. E. Imbeaux,
Engineer-in-Chief of Pontset Chaussées at Nancy, who has made a life-
study of the hydrology of this area. Lieut.-Colonel Alfred H. Brooks,
Chief Geologist to the American Expeditionary Forces, also gave
much help over work in this area.
At Courban the aerodrome was on ground formed of the upper-
most beds of the Great Oolite, and it was expected that the limestones
would yield a good supply. Two bores were put down about 700 ft.
but only yielded supplies of about 2,000 gallons per hour, although
from one of the bores the water actually flowed at the surface at the
rate of about 200–300 gallons per hour. The limestone proved to be
very compact at a depth, and only small water-bearing fissures were
Struck.
(d) Central Group, Canadian Forestry Corps.-Several saw mills in
the Central Group of the Canadian Forestry Corps were in need of
an adequate Supply of water during the summer of IQI8. The
Operations were being carried out in the area between Rouen, Eveux
and Alençon. Much of this area is underlain by chalk, but conditions
are rather different from those in Picardy. Here there is a great
Covering of “clay with flints,” some IOO ft. thick on the plateau, and
also the lower beds of the chalk are passing into the sandy facies of
the “Sables de Perche.” The conditions made boring more difficult,
but good results were obtained in the bores which were made by the
Australian Electrical and Mechanical Mining and Boring Company.
In the neighbourhood of Alençon old palaeozoic grit rocks come to
the Surface, and in this area it was advised to use surface water, and
not to bore,
4. EXTRACTION OF WATER FROM THANET SANDS.
Geological Conditions.—The strata under the Flanders Plains are –
Palaeozoic —Slates and mudstones—Devonian or older.
Cretaceous —Hard marly chalk with flints.
Tertiary —(a) Landenian clays and sands.
(b) Ypresian or London clay.
Recent alluvial and loamy deposits.
Of these, the only strata which yield water, with the exception of
Certain sands in the Recent deposits, are the sand-beds of the Lan-
denian. These sands are some 50 ft. thick as a general rule and over-
lie the Louvil clays which are the basal beds of the Tertiary. The
sands lie at a depth of 250 to 400 ft. below the surface, immediately
beneath the thick impervious mass of Ypresian clay.
Borings made into these sands usually started with 8-in. Casing,
which was driven firmly into the blue clay to ensure that none of the
recent superficial Sands worked down into the bore; 6-in. Casing was
used to line the bore in the clay until the “green sand " was reached.
I6
The Landenian or Thanet sands are extremely fine and of a grey
to grey-green colour, and were usually spoken of as the “green sands.”
The extremely fine nature of the sands made the problem of obtaining
Water in quantity from them by means of bore-holes a difficult one;
Various methods were tried from time to time; these were —
(a) Air-lift without strainer.
(b) Tube-well pumps— (i) with gauze strainer;
(ii) with horse-hair strainer.
(c) Ashford strainer.
(a) Air-Lift without Strainer.—This was tried experimentally at
Houtkerque. The green sand was struck at 369 ft. below the surface.
There was 30 ft. of sand before the underlying Louvil clay was
reached. Water rose to within 21 ft. of the surface. A 130 c. ft.
per minute compressor was used—starting pressure about 150 lbs.
per Sq. in. which dropped to 75 lbs. per sq. in. when running. The
Only result with this method was to bring up large quantities of a
mixture of Sand and water. A large cavity was formed at the bottom
Of the bore. The water never pumped clear of sand from this bore.
The volume of air was evidently much too great.
Some bores were made near Neuve Eglise and were being tested
with various types of pumps when the experiments had to be stopped
for military reasons. One bore, however, which was cased only
I ft. 8 in. into the sand, was tested with a 21 C. ft. per minute Ingersol
Rand 4% in. × 5 in. Compressor. This yielded 450 gallons per hour
of water, which was only slightly cloudy and Sandy, and would
probably have cleared after being pumped for a week or two. This
small compressor gave much better results than the large One used
at Houtkerque.
(b) Tube Well Pumps.
(i) Gauze Strainer.—This was the type of Strainer generally
used. The gauze was of brass with 60 mesh per linear inch Soldered
over a perforated 4-in, iron pipe and protected by perforated brass
sheeting. Gauze of this type was found to hold back only I5 to
30 per cent of the sand. The result was that as soon as the pump was
speeded up to deliver more than about 300 gallons per hour, sand
was sucked into the bore, and this not only choked the bore, but
also rapidly destroyed the leathers of the pump buckets. When
bores fitted with this type of strainer were not pumped at more
than 300 gallons per hour, the water came up reasonably clear, but
even then the bores became sand-choked from time to time and
needed flushing Out.
(ii) With Horse-hair Strainer—This form of strainer was experi-
mented with in only one bore, and, although it appeared to give
results slightly better than the brass gauze, the test was not
sufficient to permit of any definite conclusions.
17
(c) Ashford Strainer.—The Ashford strainer used in France con-
sisted of an octagonal column formed of rods kept in place by internal
rings with copper-wire spaced to leave 4/IOOO to 6/IOOO in. between
wires; for each 50 ft. run of strainer this left open Spaces equal to
an opening of about 400 sq. in. In a test made at Cunewele near
Hazebrouck 50 ft. of Ashford strainer was used; this was embedded
in the Thanet sands so as to give maximum percolating surface.
Rest water-level was at 62 ft. from the surface : the air Compressor
used was a 60 c. ft. of air per minute Broom & Wade (Coventry)
Simplex set, starting pressure 95 lbs. per sq. in. and running pressure
40 lbs. per Sq. in.
At first a I-in. air pipe inside the 4-in, rising main was used, but
this was not satisfactory owing to the quantity of water being too small
for the area of the rising main. Later a 2-in, pipe was put inside the
4-in. and air blown down between the 4-in. and 2-in. pipes, the 2-in.
pipe thus being used as the rising main. This proved a Satisfactory
arrangement, and a yield of nearly I,OOO gallons per hour was
obtained. The water was practically free from sand.
Conclusions.—The work done in the Landenian or Thanet sands of
Flanders would seem to point to the following conclusions —
(i) That the sands will only yield a certain volume of water
per diem without having bad effects on the bore. When, after
several hours' rest, the water fails to return to its former level, it
would appear to indicate that the sands in the neighbourhood of
the bore are being “ dried out,” due to the slow rate of percolation
Of the water through the excessively fine sand. In other words,
a Zone of Sand which is not fully saturated with water is being
produced round the bore. The daily yield of a bore should be
between 6,000–IO,OOO gallons without lowering the rest level of
the water. The gauge of the quantity of water which can be taken
from a bore would seem to be the rest level after pumping has ceased
for several hours.
(ii) In order to avoid raising sand when pumping, one or two
things must be done —
(a) Pump slowly at a rate of about 300 gallons per hour.
(b) Have an efficient strainer which will keep back the sand
when pumping at a rate of about I,000 gallons per hour.
The Ashford strainer when wound to about 4/Iooo to 6/IOoo in.
spacing would appear to fulfil the latter conditions.
For a strainer to be efficient in this type of deposit it must hold
back a sufficient percentage of the sand to form a natural filter of the
larger grains of sand outside the artificial strainer. While forming
this natural filter only a small quantity of sand must be drawn into
the bore, for, if large volumes are sucked through the strainer,
cavitation tends to set in, which breaks down the natural arrange-
B
I8
ment of the sand, and prevents the natural filter from forming. It
would appear advisable, however, in these extremely fine sands to
break up the natural arrangement of the sand for a short distance
(probably only a few inches) around the bore-hole. When this was
done a more efficient natural sand-filter seemed to form.
(iii) A steady flow of water, such as induced by an air lift pump,
is preferable to the pulsating flow of a tube well pump. The
pulsating is deleterious to the strainer itself and tends to disturb
the Sand astride the strainer.
(iv) The Scheme of artificially introducing a filter of coarse sand
outside the Ashford strainer was not tried owing to the fact that
larger bores would have been necessary to enable the sand to be
fed down between the casing and the filter. It would probably
be advantageous to have an artificial sand filter, but, unless this
filling was of an appreciable thickness, it would be difficult to
prevent a Small volume of fine sand from being sucked into the
bore-hole during the initial stages of pumping. The removal of
this Small volume might easily cause a readjustment in the
artificial Sand filter, resulting in a breaking up of the original
arrangement around the strainer, thus exposing portions of the
Strainer direct to Thanet sands.
(v) Another type of strainer known as the Beeby Thompson
Strainer was on Order, but did not arrive in France in time to
be tested.
5. CARD INDEX OF BORES.
When it was seen that boring would be extensively used as a
method of obtaining water, suitable forms were drawn up for
forwarding the records to G.H.Q. These forms were of foolscap
size and had spaces for details of the strata and pumping machinery,
output, etc. As the forms were received from the Armies the
information on them was entered on cards which were kept in a card
index arranged alphabetically by place names. A sample of One
of these cards is given below, and contained practically all the
information on the larger forms received from the Armies —
BETHENCOURT, 57*v 9 d. 8.2. Altitude 42 metres.

Pºm Thickness. Nature of Strata. Remarks.
O IO Soil and clay ... ... | No. C/4I.
IO 25 Chalk and flint
35 5 Chalk © tº
4O I2 Chalk and flint
52 I58 White chalk marl
2 IO 43 Blue chalk marl
253
I9
DETAILS OF PUMPS AND OUTFIT.
Air Lift. Deep Well Pump.
Compressor, Broom & Wade, mounted Pump
Engine, } on lorry. Engine
Starting Pressure IO4 lbs. per Sq. inch. Depth of Pump
Running ,, IOO , , , , 3 3 Barrel from surface ft.
I30 cubic ft. Air per minute. Diameter of Pump
245 ft. of 4-in. Rising Main. Barrel ins.
35 ft. of I-in. Air Pipe. Length of stroke ins.
Yield, I2,000 gallons per hour. Strokes per minute.
Water Level at rest, 32 ft. from surface.
5 y ,, after pumping 36 ft. ,
47 ft. of 8-in. dia. Casing.
(Signed) X. Y. Z. O.C. No. 3 Water Boring Section, R.E.
A map of I/250,000 scale, with the position of each bore marked
by a small circle, and the place name by which the bore was known,
was also kept up to date so that the map acted as a cross index to
the cards.
During the war a total of over 470 bores for water were made by
the British Armies.
6. CURVES OF MARL SURFACE.
The chief percentage of the bores were in the chalk country of
Artois and Picardy. The bores were as a rule carried down through
the water-bearing Upper Chalk into the marls of the Middle and
Lower Chalk, in order to give sufficient submersion for the use of air-
lift pumps. The method of boring by percussion made it extremely
difficult to get accurate records. The character of the strata, more-
over, made it difficult for the drillers to tell within a few feet the
junction between the chalk and the underlying marls, particularly
as broken flints frequently got mixed up with mari and led to the
term “marl and flint.” When the marls could be studied in sections
and mining galleries, flints were absent except for a very occasional
layer of tabular flint. When, therefore, the term “marl and flint ’’
was used, it was presumed that the marls of the Middle Chalk had
been reached, but that a few flints had been knocked out of the
Upper Chalk and had been pounded up with the marls.
It resulted that it was impossible to tell with any accuracy the
exact depth at which the marls were reached
During the early part of IOI8 Sufficient data were available to
draw Contour lines at 25-metre intervals of the surface of the marls.
In order to arrive at the altitude of the surface of the marls above sea
level, the altitude of the ground at the site of the bore was estimated
2O
from the contours of the 1/40,000 map, and the depth from ground
level to the surface of the marls in metres was subtracted. This
gave the data from which the curves were drawn. The figures thus
arrived at were open to several errors, viz. –
(a) The difficulty in recognizing the surface of the marls when
boring ;
(b) The errors in the contours of the 1/40,000 map ;
(c) The errors in estimating the altitude when the bore was
situated between two contours.
Bores were, however, sufficiently numerous to enable some
interesting results to be obtained. As new records came in they
were entered on the map, and the curves corrected to conform with
the additional data. The final result is given on Plate II. It should
be mentioned that the curves agree in essential points with those
published in Lemoine’s “Bassin de Paris" from a map by M. G.
Dollfus.
On looking at Plate II the most striking thing is the general
agreement between the direction of folding of the strata and the
direction of the rivers. This has always been pointed out by the
French geologists. It will be noticed that the syncline of the Somme
apparently has its axis somewhat to the South of the river.
Immediately south of the Authie there would also appear to be a
Synclinal trough. This is particularly apparent near the phosphate
districts of Beauval, Beauquesne, and Raincheval.
The next marked syncline is the Scarpe-Upper Ternoise Valley.
{Dn this line is the low col between the west-flowing Ternoise and the
east-flowing Scarpe, which is crossed by the main road and railway
from St. Pol to Arras.
The anticlinal ridge between the Somme and the Authie rises to
the IOO-metre level south of Candas, but appears to be more of the
nature of an elongated dome rather than a true anticlinal ridge.
The case of the ridge separating the Authie and Ternoise—Scarpe
synclines is different. The marls rise to an altitude of I40 metres,
and although they fall to an altitude of 65 m. to 70 m. in the
neighbourhood of Bapaume, the axis appears to be in line with that
which gradually falls from the east, as shown by the line of the
75 m. curve which reaches to Nurlu. This axis is practically the
same as the Cayeux's axis of Artois. (See Ann. Soc. Géol. du Nord,
Vol. XVII., p. 71 and Plate.)
South of this axis one branch of the Somme Syncline Coincides
with the line of the Somme to Peronne, and is continued in a South-
easterly direction towards St. Quentin. -
A dome of relatively high ground with its centre near Chaulnes
separates the Amiens–Peronne–St. Quentin Syncline from that of the
Avre; this latter being a direct continuation of the Somme Syncline
2I
below Amiens. To the north the marls gradually fall to the Basin
of Orchies, as illustrated by M. Gosselet's work.
The question of whether the north and south-flowing rivers have
any connection with the geological structure is not so obvious.
Apart from the upper Escaut the most striking line of north and
South-flowing streams is that followed by the new Canal du Nord.
From the river Sensée this canal follows the Hirondelle, then by
means of a tunnel crosses the ridge into the valley of the Tortille.
Near Peronne it joins the Somme where that river takes such a
remarkable change of direction from east–west to north–south.
Near Nesle the canal leaves the Somme, which gradually Swings east
and follows the line of the low ground which is drained by the Ignon,
and reaches the river Oise at Noyon by the valley of the Verse.
Although the main structure of the country is clearly shown by
the N.W.—S.E. trend of the curves, there are several changes along
this N.—S. line. For instance, the curves near Cannbrai have an
E.N.E.-W.S.W. direction, but change to the usual N.W.—S.E. trend
on the line of the Hirondelle. More important than this is the
marked lowering in the main axis of Artois between the high area
west of Bucquoy and the high ground to the east.
The bulging-in of the dome along the line of the Somme south of
Peronne would appear to be some indication of secondary folding
along this north and South axis.
The question of practical interest is to see if bores situated in the
Synclinal areas yield better Supplies than those on the anticlines.
As far as the evidence of the bores goes there is practically no
difference in the yield of bores in the anticlinal areas compared with
those in the synclinal, provided both are situated in favourable
positions, such as a dry valley. On the plateaux, however, the fact
that on the anticline the thickness of water-bearing chalk is greatly
reduced has a bad effect on the yield, thus the bores of Saulty,
Monchy-au-Bois, Fienvillers, etc., where the thickness of water-
bearing chalk was Small, only yielded small quantities of water. It
does not follow that bores on high ground in a synclinal area
necessarily yield good supplies, although in some cases, such as
Beaurains, a good yield was obtained from a bore on the top of a
hill. It would appear, therefore, that the local topography has
much more effect on the water-bearing properties of the chalk than
the larger tectonic structures.
CHAPTER II.
MINING, FIELD POSITIONS, ETC.
7. MINING IN REGARD TO WATER LEVEL.
The first geological test bores were put down at Mont Kemmel
in May, IQI6, and proved the existence of the water-bearing Kemmel
sands between the levels of the 70-metre and 60-metre contours at
that hill. These sands were subsequently traced over large areas
northwards through Wytschaete and Hill 60, near Ypres, to Passchen-
daele. In most cases it was impossible to obtain dug-outs in these
sands, which were usually so charged with water as to be “running ”
(see Fig. 9 and Plate V).
The geological boring sets were next transferred to Hill 63, to the
north of Ploegsteert, and proved that it was possible to excavate
dugouts satisfactorily there in the Paniselian clay immediately
above the Ypresian clay. Dug-outs were at once made there. These
dug-outs, when completed, accommodated about 3,000 troops.
The geological boring sets were next moved to Givenchy-lez-la-
Bassée at the request of the Controller of Mines of the First Army.
The enemy a short time previous (June 22nd, IQI6) had done some
damage to our lines by blowing the “Red Dragon Crater ’’
(Fig. I). It was obvious from this “blow ’’ that his mining system
must have been somewhat deeper than our own.
Previous to this blow some of our mining galleries in this sector,
east of Bunny Hutch Shaft, had been inundated through the workings
having struck the artesian water in the chalk, but there was no
accurate record as to the exact depth at which the water horizon had
been touched. Accurate determination of the exact depth to which
mining could safely be carried in this important sector now became
very urgent. The Hordern boring sets were employed successively
at North Shaft and Coventry Shaft (Fig. 2), and as water under
pressure was expected, a boring bit was used with a diameter of
only $ in. In each case, as soon as the Louvil clay was penetrated,
and the surface of the chalk reached, artesian water gushed up the
bore. Small bags of oats, of haricot beans, rice and wheat were
forced down the bore-hole with the boring rods, and the material
allowed to swell for about a couple of hours, with the boring rods
resting on top of the bags, so as to prevent the artesian water forcing
them out of the bore. As soon as the bags had swelled Sufficiently
to grip the sides of the bore firmly, the boring rods were withdrawn,
and the flow of the water having been checked, Small bags of Portland
cement were forced down the bore where they were able to Set. The
22
23
sealing of the bores by this method was fairly satisfactory, but the
operation was somewhat tedious. A hollow rubber stopper, similar
to those used for corking bottles containing effervescent liquids,
would probably be quicker and more effective in stopping the flow of
the water; or, for larger bores or openings, the method successfully
adopted by Captain J. W. Fidoe, R.E., might be followed, which is
this —When, during IQ18, a sump at Givenchy was accidentally
carried down too close to the chalk surface, and the artesian water
started bursting up through the clay, concrete was at Once applied
and heavily weighted on top, but the artesian water kept forcing
its way through the concrete. A short piece of iron pipe with a tap
at the top was then placed vertically in the concrete, so that its
lower end was open to the rising artesian water. The tap was left
full open, so that the water flowed freely for about a week, thus
taking the water-pressure off the concrete and allowing it to set.
The tap was then closed, and the mining system was saved. The pipe
afterwards served the purpose of a standpipe for supply of pure
water underground to the tunnellers.
The whole operation of making these two bores and Sealing them,
and tracing the outcrop of a certain fossil shell bed (containing
cyprima morrisii) occupied about two days. The evidence of the two
bores gave the apparent dip of the strata in one direction, and from
that of the Outcrop of the shell-bed the apparent dip was found to
be in a direction more or less at right angles to the first. From these
two directions the true dip was easily calculated, and the exact depth
of the artesian water surface was thus determined. From this new
datum a new mining system for the Givenchy sector was laid out, and
all underground works at Givenchy from then until the final great
defence of Givenchy in June–July, IQI8, were laid off in reference to
this horizon.
The problem, though of course an extremely simple one, was
essentially a geological One, and had the geological examination been
made earlier, it is probable that the Red Dragon Crater would never
have been blown.
8. DETERMINATION OF CHALK UNDERGROUND “WATER TABLE.”
In August–September, IQI6, it became a matter of importance
to determine —
(a) The actual depth at that time to the underground “water
table '' in the chalk (i.e., the depth to the surface in the
chalk), and
(b) the exact amount of Seasonal variation in the level of this zone.
For example, in late autumn the “water table " is usually at its
löwest level, whereas after the winter rains its surface rises. It
followed, therefore, that if mine galleries were carried down to the
24
level of the top of the chalk “water table '' in the autumn, there
would be a certainty of their becoming inundated by the rise of the
“ water table '’ the following spring. At the time investigations
Commenced there was much uncertainty in the British Armies
engaged in tunnelling in chalk country (First and Third Armies) as
to how much to allow for rise of the chalk “ water table '' and how
the approximate date of the rise could be predicted. The amount of
Seasonal variation was set down at about 6 ft.
The underground “water table '' in the chalk must be carefully
distinguished from “ quarry water.” Almost everywhere in the
chalk, at 8 ft. Or so below the surface, there is enough water stored
in the very fine pores of the chalk to make the chalk slightly moist,
So that, if drilled with an auger, it works up into a stiff putty-like
Substance. This water is stored in microscopic (capillary) cavities,
and is not free to circulate to any great extent. This water is the
“ quarry water.”
The water below the “water table '' on the other hand, is stored in
countless Small cracks and fissures in the chalk. These are most
numerous and carry most water in the “chalk without flints '' of
the Upper Chalk (see (a) of Fig. 5). In the “chalk with fints ''
underlying the preceding, the water of the “water table '’ still
circulates fairly freely in numerous minute fissures, and in places in
larger fissures.
Underlying the preceding is the marly chalk, the lowest formations,
in the chalk regions, in which the mine galleries were driven. The
underground water in this formation does not circulate nearly as
freely as it does in the two preceding.
The movement of the water in the chalk marls is restricted to the
larger fissures which may be Some scores of yards apart from each
other, so that galleries driven in this formation may be practically
dry even when they are below the general “water table "surface of
the area, provided they do not strike a fissure.
The variation of water-level in chalk with the seasons depends
O1] ...—
(i) Rainfall.
(ii) Evaporation.
(iii) Run-off of rainfall—
(a) Superficial, in brooks and rivers,
(b) Underground, as a more or less continuous sheet creeping
seawards, or discharging by Springs into low-lying
areas like those of the Flot de Wingles, the La
Bassée Canal, the Sensée Marshes, etc.
Evaporation is perhaps the most important of these factors; thus
a heavy rainfall at time of maximum evaporation (as, for example,
in July or August) produces little, if any, effect on the level of the
25
chalk “water table.” On the other hand, a similar rainfall at the
end of winter or early spring, when evaporation has practically
ceased, produces a rapid rise in the “water table.”
As regards its general shape, the underground “water table "
rises under the hills, and sinks towards the main river valleys and
more important springs. Its upward and downward movement,
following the seasons, is greatest when comparatively high hills, like
those of the Loos salient, Calonne and Souchez, adjoin low-lying
areas like those of the Flot de Wingles, the Souchez River, the La
Bassée Canal, etc.
In this case the “water table '’ has a seasonal movement of the
kind shown in Fig. 5 (b) (the movement hinging on the above men-
tioned low points of outlet).
The “water table '' surface rises under the hills for two reasons,
at least :——
Like a river, in flowing from under the hills to lower-lying areas,
it develops a definite grade owing to the frictional resistance of the
Openings in the rock through which it is circulating (increasing
porosity lessens the grade; decrease of porosity steepens the grade).
The rainfall is usually heavier on the hills than on the lower
ground, hence a greater amount of water percolates under the hills
than under the lower ground.
At Croydon Corporation Waterworks in England, well gaugings show
that water levels vary from late autumn to spring by as much as Too ft.
Information was obtained in regard to this subject, on the Western
Front, in two ways — r
(a) By boring, to find out exactly at what depth below mine
galleries the chalk water level lay at any particular time ;
(b) Examining the daily or weekly records kept for many years
past by coal-mining companies in this area, and then
referring the actual level found for the chalk “water table ''
at any particular military mine to its proper place, for the
time of the year on the mean curve of “water table ''
variation calculated from the colliery records. Corrections
dependent on distribution of rainfall for the particular year
in question had also to be applied.
As regards (a), the light geological boring sets were used, and at
LOOS, at Hill 70, The Copse, The Triangle and The Double Crassier,
after some trouble in getting through the layers and lumps of flint,
the exact level of the Surface of the “water table '' at each of those
mines was successfully determined.
In the case of Hill 70 it was necessary to bore through over 40 ft.
of tough chalk and flints, which occupied two days, before the surface
of the chalk “ water table '' was touched. There was no difficulty
in telling when the auger had reached the top of the “water table.”
26
As long as it was boring in the chalk above that level, the auger, when
withdrawn from the bore, brought up in its spiral chalk of the con-
Sistency of putty, there being enough quarry water to enable the fine
chalk borings to cohere; but as soon as the “water table" was
touched, the auger brought up the pulverized chalk in the form of a
thick, white, milky substance which dripped off the auger. This was
the crucial test, viz., if the material dripped off the auger when freshly
Withdrawn from the borehole, it was concluded that water level
was reached.
Another test was the sucking sound that the auger made at the
beginning of the upward pull after water had been reached.
The depths to the surface of the chalk “water table " in relation
to the mining systems in the Loos Salient were determined by the
above method in September, 1916. The next step was to compare
them with any records which tunnelling companies had preserved
of the former level of the table when it stood higher earlier in the
year. Only a few of such observations were available.
Next, enquiries were made amongst the engineers of the French
Collieries as to whether they had any continuous records of chalk
"water table " variation extending over a number of years.
M. Malatray, the Chief Engineer of the Compagnie des Mines de
Bethune, very generously placed at disposal the whole of his very
valuable data on this subject, extending over the years shown on
Fig. 3. Efforts were made to trace a relation between the curves of
variation in Chalk “ water table '’ level and those of the local rainfall,
but without success at first. It had been the received idea among
British geologists that there was a delay action, or lag, of about three
to four months between any peak of heavy rainfall and the following
peak in chalk “water table '’ level.
The Commandant of the Meteorological Section of the British
Armies Solved the problem at once by pointing out that the evapora-
tion factor was an extremely important one, and that the correction
for this must first be applied. There were no accurate data on this
head for Northern France, but data for such parts of the South-East
portions of England as had climatic conditions most nearly approach-
ing to those of Northern France were procured. These corrections
are shown by the pink areas on Fig. 3. A small correction (shown
green on the above figure) was also applied for run-off discharged by
brooks and rivers. These two quantities having been deducted
from the gross rainfall, the net rainfall which percolates, and which
is the only part of the rainfall which is effective in raising under-
ground water level, was calculated approximately. The relation
between percolating-rainfall curve and variation of “water table ''
curve then became very apparent.
It will be seen from Fig. 3 that (after the big deduction is made for
evaporation during the months of April to October inclusive) it is
27
apparent that there is a lag of only from two weeks to a month in
the peak of the rainfall and that of the chalk “water table.”
Experience shows that there is a greater lag in rise of water-level
in low-lying areas than in high areas. For example, at Hohenzollern
the maximum water-level in 1917 was three weeks later there than
at the Triangle. The lag at Hohenzollern may thus amount to five
or even six weeks. This is probably owing to the time that it takes
the crest of the wave of the chalk water to arrive at the lower levels,
the rainfall as already stated being heaviest on the highest ground,
and so bringing down, as it were, a flood in the “water table" which
travels like the flood in a river, from the source towards the Outlet.
This conclusion as to a general lag of only about three weeks is
obviously very important, as it makes it at Once possible to predict
exactly when the chalk “water table '' will attain a peak after any
particular period of heavy rain. The necessary data are —
Knowledge of level of “water table '' before rain began.
Amount of rainfall lost by evaporation.
Amount of rainfall lost by run-off.
Average amount of rise of “water table '' per unit of percolated
rainfall as observed in previous years.
It was now possible to draw up a table for use by the various
Tunnelling Companies, to show them just up to where the “water
table '' would rise, on the assumption of a maximum rainfall during
winter when evaporation is at a minimum.
In all the Loos mines, including Hill 70, the calculations made in
September of IQI6 worked out fairly closely (within a foot or two)
of the maximum (almost a “record '' maximum) chalk “ water
table '' level in January, IQI7. It was found in September, IQI6, as
the result of these calculations, that the new mining systems begun
at the Copse, the Triangle and the Double Crassier, were already
considerably too deep, and SO another system was laid out at a level
from I2 ft. to I5 ft. higher. When in January, IQI7, the water rose
to its maximum level, it just reached the floor of the main lateral of
this latest system of galleries. At Hulluch and Hohenzollern, how-
ever, the “water table '' rose about 2 ft. higher than had been
estimated, as enough allowance had not been made for the
“ travelling wave '' from the highest point of chalk water towards
the hinging point or Outlet at the La Bassée Canal and the Flot de
Wingles. In other words, the movement of chalk water level is not
merely a straight up-and-down hinging motion, as shown at (b) on
Fig. 5, but is a wave movement Superimposed on a hinging movement.
As regards the actual amount of variation of chalk water-level in
the La Bassée Canal to Souchez River area, this is shown on F ig. 4.
The maximum variation was found to be 30 ft., at the Triangle near
the Double Crassier.
28
In I917, in the abnormally rapid rise of chalk water level, between
Christmas Eve, IQI6, and 8th January, 1917, the water rose 18 ft.
in fifteen days, and at the Triangle it rose no less than 30 ft. above
its minimum level of November, 1916. At Calonne the rise was fully
26 ft. ; at the Copse 22 ft. ; at Hill 70, 22 ft. , at Hulluch I2 to
I5 ft. at the Hairpin from 18 ft. at the south end to II ft. at the
north end. In Hohenzollern the rise was from II ft. at the south
end to about 9 ft. at the north end. From here the variation steadily
lessened to practically zero at the La Bassée Canal near Pont Fixe.
The whole of this work of predicting for the Tunnelling Companies
just up to where chalk “water table '' level would rise would, of
Course, have been impossible without the valuable curves supplied by
M. Malatray, and there is no question that this information contributed
Very much to save some of the most important mining systems.
The determination of the variation of the chalk “water table '' at
Givenchy-lez-la-Bassée and the Loos salient was eventually extended
to Calonne, Vimy and Arras. In the course of investigating the
geological Conditions at Vimy, partly by boring with the modified
“ACme " drilling plant, and with the “Wombat "boring machine,
and partly by examining the sections in the tunnels and shafts of
the I76th Tunnelling Company, R.E., evidence was obtained useful
from the military, as well as from the purely scientific point of view.
Q. RELATION OF MILITARY MINING TO GEOLOGICAL STRUCTURE.
(a) The Vimy Ridge owes its origin to a very important geological
structure, the Marqueffles Fold and Fault. This tectonic feature has
a general W.N.W. to E.S.E. trend. Near Souchez this structure is
shown on the French geological map of Arras (I/8O,OOO and
numbered 7) as a fold, but there has been some doubt as to how far
the displacement of strata in this neighbourhood is due to faulting
and how much to folding. The total amount of displacement effected
is at least I90 ft. (58 metres). In places, GOSSelet estimates the
displacement as up to 95 metres. British evidence shows (vide
Fig. 6) that about 130 ft. of this is due to folding, and 60 ft. to
faulting. The geological conditions, as shown by this evidence,
inasmuch as they brought down the clayey and Sandy beds of the
Tertiary strata into a very suitable position for military mining,
favoured an attempt to tunnel under the very important stronghold
of the enemy which gave him such command and fine Observation
-—“The Pimple.” The scheme was to drive a gallery from D.5
shaft (see Fig. 6) through the chalk near the bottom of the monocline,
so as to reach the Louvil clay at a sufficient distance from the enemy
lines for the latest part of the tunnelling in the chalk to be inaudible.
Once the Louvil clay and its underlying Sand were reached, it should
be quite possible to tunnel, without being heard, right along this bed
of clay until a point should be reached right under the enemy's
29
strong points. Previous to the starting of this Scheme, as accurate
a survey as possible was made of the Louvil clay outcrop which there
just touched, and in places entered, the British front line of trenches.
The geological evidence, chiefly obtained from the French maps and
scientific papers, proved correct and was verified by Small bores.
Had the Vimy offensive of 9th April, 1917, been postponed for about
a week, the end of the offensive tunnel would probably have been
carried right under the enemy strong point. As it was, it had arrived
by 9th April, 1917, within about 70 ft. of the enemy's front line, as
shown on Fig. 6. This is a special example of the importance of
determining geological structure accurately before military mining
is commenced.
Another point brought to light by the geological borings here,
partly with the “Acme'' and partly with the “Wombat '' boring
machine—was that at a depth of about I50 ft. (46 metres) below the
surface of Vimy Ridge a thick layer of marly clay occurred, Sufficiently
soft to admit of silent tunnelling being carried on in it. A deep
mining system in these marly clays would have been developed had
time permitted. Meanwhile the great attack (which proved so
successful) between Vimy and Arras was launched on 9th April,
I917. It may here be mentioned that a short time previous to this
attack five horizontal bore-holes were made from the ends of the
Subways, along which latter the attacking infantry were brought up
under cover to the edge of “No Man's Land.” The subways,
preparatory to the boring, mostly with about 30 ft. of cover, chiefly
chalk, were inclined upwards at their blind ends until the cover was
reduced to about I6 ft., and then a chamber about 6 ft. × 6 ft. × 7 ft.
was excavated. “Wombat '' boring machines were introduced into
the chambers of five subways, and 6-in. bores were made to a length
of about 200 ft. under “No Man's Land "up to the enemy's trenches.
These bores were then charged with ammonal cartridges, 5% in. in
diameter. Out of this total of five bores which had been completed,
three were utilized during the attack, chiefly in the area between
Neuville St. Vaast and La Folie Farm, and were fired at zero on
9th April. The explosions formed, instantaneously, wide trenches,
One of the two near Chassery Crater being IQ5 ft. long, 25 ft. wide
at the Surface and I4 ft. deep , the other 174 ft. long, 25 ft. wide at
the Surface and I5 ft. deep. The firing of these bore-holes at once
opened up these explosion-trenches from the ends of the subways
across “ No Man's Land,” and the leading troops swarmed to the
attack through them, but the enemy made so little resistance that the
remainder of the troops had no need to take cover, and went straight
over the top. The official report on the result of these bore-explosions
at the time was that they afforded excellent cover for troops, and
would probably be most valuable on the flank of an attack.
Geological examination had often to be made of the ground where
30
it was proposed to use the “Wombat" borers. If the formation
Was clayey, a twist auger was used, and if of chalk, with or without
flints, a calyx barrel with steel cutter was employed. The boring
past the flints needed percussion, and was therefore too noisy to be
used in close proximity to the enemy's lines, except in cases to be
detailed later.
The photograph, Fig. 7, shows one of these explosion-trenches
near Chassery Crater. As the photograph was taken over twenty
months after the “blow,” the trench has been considerably filled
up through rainwash.
(b) For some time previous to the Vimy attack of 9th April, 1917,
much time and thought had been given to the preparation of the
immense mining System from Ploegsteert, along the zone Messines,
Wytschaete, St. Eloi, to Hill 60, near Ypres. One of the most
difficult mines to construct was that of Boyle's Farm, between
Wulverghem and Messines, extending to Ontario Farm, the latter
being strongly held by the enemy. The difficulty arose chiefly from
the great thickness (93 ft.) Of water-bearing alluvials, chiefly sands
and Sandy clays, Overlying the blue clay, in which the driving of
galleries was possible. Two unsuccessful attempts were made to
sink Shafts through the running sands. Then, the most favourable
spot having been selected, as the result of the evidence of geological
test bores, a third atetmpt was made, which eventually proved
successful. The mining system shown on Fig. 8 was developed by
the 171st Tunnelling Company, R.E., steel tubbing being sunk
through the running alluvials well down into the Ypresian clay (blue
clay). When the gallery had reached the point shown at about
480 ft. distant from the bottom of the Winze Shaft, the clay in the
roof softened, and water with sand started to come in. With great
promptitude the end of the gallery was sealed off. A careful
geological examination was made, with a view to estimate the exact
maximum depth of the old alluvial channel, so as to decide how much
deeper the tunnel would have to be carried in order to be safe from
the running sand and the gravel. The conclusions were based on a
series of bores made by the Belgians, details of which were published
on their maps, as well as on evidence from workings in the vicinity,
and particularly on the character of a few blocks of shingle up to
I ft. in diameter which had worked their way down into the clay
at the end of the tunnel, and gave good evidence by their coarseness
that the very bottom of the channel had been touched at the end
of the sealed-off gallery. The gallery was dipped another 7 ft. and
the bottom of the channel was just cleared, with a sufficiency of clay
in the roof to keep back the water.
This tunnel was completed, chambered and charged just in time
to be fired at the attack of 7th June, IOI7, and the resulting explosion.
was very satisfactory.
3I
(c) The Messines–Wytschaete—Hill 60 Mines.—Another serious
geological difficulty, in mining in this zone, apart from the thickness
of the quarternary alluvials of the Petite Douve Valley just mentioned
was the presence of the water-bearing Kemmel sands. These sands
were first identified at Mont Kemmel, where they outcrop between
the 70 metres and 60 metres contour. There they formed quite a
useful source of water supply on a small scale, but it was impossible
to make dug-outs or tunnels in them, excepting in the case of small
isolated knolls, where natural conditions for drainage were exception-
ally good. Traced north-eastwards, the Kemmel sands gradually
dip, so that, on the eastern slopes of Wytschaete Hill they outcrop
between the altitudes of 58 and 48 metres. They are therefore
about Io metres in thickness. The running character of this sand
is well seen in Fig. 9, in which is shown the railway cutting at
Hill 60. The concussion of exploding mines and bursting shells has
caused the banks of the cutting to collapse ; and Sand and water
have flowed inwards from the bases of the slopes of the Cutting,
partly filling it up. It was these Kemmel sands that made it
impossible to obtain satisfactory dug-outs at Verbrandenmolén,
Battle Wood, Shrewsbury Forest, Clapham Junction, Dumbarton
Wood, Polygon, and many other areas extending through Zonnebeke
along the Passchendaele Ridge.
Fig. IO shows the general geological conditions in the Flandrian
area between Ploegsteert and Hill 60, along the zone where these
important mines were situated. It will be seen that the Only One
of them which penetrated the Ypresian clay (blue clay) to any depth
was the St. Eloi mine.
With the exception of the mines in the Ploegsteert area all the
rest of the mines were in the sandy clays and sands of the Paniselian
formation (SO-called after Mt. Panisel, near Mons, where it is typically
developed).
Fig. IO shows that mines such as those of Kruisstraart, Spanbroek-
molen and Peckham, were driven in the sandy clays just below the
base of the water-bearing Kemmel sands. Had geological advice been
available at the time these mines were begun, there would certainly
have been a recommendation to sink a little deeper before tunnelling,
SO as to place the galleries well below the level of the Kemmel sands,
excavating them in the brown to greenish clay, which there usually
forms the base of the Paniselian formation. This was done, for
example, in the case of the mine at Maedelstede Farm, at the Cater-
pillar (Hill 60 B) and at Hill 60 A, in which the galleries were driven
along perhaps the best possible geological horizon.
M. Ch. Barrois, the Professor of Geology at the University of Lille,
stated that at the time the Messines–Wytschaete mines were fired
the whole of the City of Lille experienced what seemed to be a sharp
shock of earthquake. He and all his household were wakened by it,
32
and dressed hurriedly in anticipation of possibly a more severe shock
following the first. Lille is about II, miles distant from the nearest
of the mines (that of Ontario). On the morning of the explosion of
the mines many German soldiers were to be seen running apparently
panic-stricken down the streets of Lille.
It is interesting to notice the effect of different geological
formations in controlling the type of crater produced by the explosion.
Reference to Fig. IO shows that one of the most disappointing craters
was that of St. Eloi. The obvious reason for this is the extreme
tenacity of the Ypresian clay (blue clay) and its resistance to disrup-
tion. In the Paniselian Sands and clays, on the other hand, the
disruptive effects of the charges were much greater, as is obvious
from a study of the craters at Hill 60, for example, as shown on
Fig. II. It is also interesting to note that at Ontario Farm, where
there was 93 ft. in depth of Soft water-bearing alluvial, scarcely any
crater rim at all was formed, the material erupted simply falling back
and almost completely filling the crater. On the other hand, in the
Paniselian formation, as already stated, the craters were well formed,
deep, and with high raised rims. For comparison of these two
types, the crater at Ontario Farm (Fig. II) may be compared with
the crater at Hill 60 A (Fig. I2).
Antecedent and subsequent to the blowing of the Messines—
Wytschaete mines, the Australian Electrical and Mechanical Mining
and Boring Company were, through their boring Section, making
large numbers of trial bores in the Flanders area, with a view to
testing the suitability or otherwise of the ground for dug-outs, battery
positions, observation posts, tunnels, subways, etc. Subways were
constructed about this time under the Ypres Canal, near Boesinghe,
in preparation for the third battle of Ypres.
IO. TEST BORES FOR SUBWAY AT NIEUPORT.
Just previous to the capture of Vimy, a special geological examina-
tion was made of the sand dunes along the Coast between La
Panne and Nieuport, with a view to ascertaining whether it was
possible to extend offensive tunnels into the sands and to construct
dug-outs. The geological report was favourable, and the 2nd
Australian Tunnelling Company attempted this rather difficult task,
using an ingenious method of timbering, which has been specially
described in the reports of the Inspector of Mines, G.H.Q. It was
officially stated that the galleries and dug-outs made in the dunes by
this Company and the 184th, 256th and 257th Companies, R.E.,
contributed very much to strengthen the position of the British
troops when the enemy took the Grande Dune on the northern bank
of the Canal, to the north-west of Nieuport, on the IOth July,
I9I7.
33
In September of 1917 it was decided to test the depth of the
Ypresian clay (blue clay) on either bank of the Yser at Nieuport.
This was done with a view to the possibility of constructing a
subway under the Yser. It was foreseen, from the geological
evidence afforded by the Belgian bores at some few miles away, that
a considerable thickness—at least 50 or 60 ft.—of running Sand,
practically quicksand, would be encountered. The boring would
have to be done more or less under shell-fire the whole time, so that
only a light hand-boring plant could be employed. For the method
adopted, Captain Stanley Hunter, of the Australian E. and M. M.
and Bo. Company, was responsible, the work being actually carried
Out by the 2nd Australian Tunnelling Company. The apparatus
and method of boring was ultimately so successful that it may be
here described in detail, with a view to guidance in the solution of
similar problems. The section and apparatus are shown on Fig Is.
II. SPECIAL PLANT FOR THICK BEDS OF WATER-BEARING SAND.
(a) Description of Apparatus.--The principle used in boring in
thick beds of water-bearing sand was that of the water-jet.
The boring rods carrying water under pressure consisted of Ił-in.
pipe in 3-ft. lengths, to the bottom length of which was attached a
calyx cutter.
The casing used was 3 in. in diameter in 6-ft. lengths.
The water under pressure was supplied by two horizontal double-
acting hand pumps Connected in Series, i.e., the discharge of one
connected to the inlet of the other. This water was led through
flexible hose to a water-swivel connecting up with the top length of
the I}-in. rods. A tripod, IO ft. in height, with a block and tackle,
enabled the casing and boring rods to be handled with ease.
A geological test boring set was used to bore through solid clay
when that bed was reached.
The complete plant consisted of the following —
I2O ft. I}-in. pipe, in 3 ft. lengths.
50 ft. 3-in. Casing, in 6 ft. lengths.
I water-swivel.
I block and tackle, with about 50 ft. of rope.
2 Trimo wrenches, and 2 chain tongs.
2 horizontal double-acting hand pumps, connected in series.
I force pump.
30 ft. Suction hose
30 ft. delivery hose
20 ft. Suction hose, 2-in. diameter
30 ft. pressure hose, I'-in. diameter
2 lifting jacks.
I complete geological test boring plant, with 120 ft. of 3-in. rods.
C
| for force pump.
} for hand pumps.
34
(b) Method of Boring.—Boring is started with the I}-in, rods
Connected up to the water-swivel, with the calyx cutter and water-jet
at the bottom. This is suspended to the tripod by a rope through
the pulley block. Pumping is commenced, and a length of 3-in.
Casing is placed over the hole with the 13-in. rods inside. A
Percussion movement is given to the latter by means of the rope
through the pulley.
Boring proceeds rapidly, and the casing sinks as the water jet
raises the sand to the surface. Lengths of casing and Ił-in. pipe are
Screwed on as required and as rapidly as possible, as the object is
not to allow the sand to pack after it has been once moved, as there
is a danger of the rods becoming fixed in it if they are deeper than
the Casing.
Pumping becomes more difficult as depth is gained, as there is an
increasing head of sand and water to overcome. The two pumps
connected together in series, as explained above, however, give
sufficient pressure for depths of 90 ft. to Too ft.
The samples are collected at the collar of the bore as boring
proceeds.
(c) Rate of Boring and Number of Men Required.—It is almost
impossible to give any exact figure of the rate of boring, in the only
case in which this method has been used, in the battle area, many
difficulties were met with and there was no chance of arriving at
an estimate of the average rate of boring. When a straight run was
obtained, an 80-ft. hole was completed in about five hours, but this
was only after many previous attempts had been made during two
days and subsequently abandoned, owing to shelling or mechanical
troubles. That figure of 80 ft. in five hours may be taken, however,
as indicative of the rate of boring with the plant equipped as described
above and free from sudden interference of the bursting of a shell in
the vicinity, which generally results in the temporary cessation of
pumping and boring and the seizing of the boring rods by the packing
of the sand around them, which cannot be removed by pumping but
necessitates the lifting of the boring rods by means of jacks. Ex-
cluding such stoppages and delays, the figure may be taken as
indicative of the rate of progress.
Six men are required on the plant—three on the pumps and three
handling the rods and Casing. -
(d) Application to Recent Marine Sands at Nieuport.—The bore
on the Nieuport side of the canal was put down from a cellar, while
that on the opposite bank of the canal was put down from the surface,
near the wall of the “ India-rubber House.”
At the latter point, the collar of the bore was 2 ft. above high-
water mark. The tidal rise at Nieuport was about I6 ft. It was
only during the interval between about half-flood and half-ebb tide
that boring could be carried out, as the pump had not sufficient lift.
o =
JJ
Two iron tanks were, however, sunk in the ground near the bore
and the canal water pumped into them, from which the water was
pumped by the two horizontal double-acting hand pumps through
the water-swivel to the Ił-in. boring rods. The Overflow water
from the bore flowed back to these tanks and was used over again
Several times, and so boring was possible even after the canal level
sank below the point at which the pump ceased to act.
The bore site was near the Putney Bridge, which was systematically
bombarded by the enemy, and this seriously interfered with boring
Operations. On one occasion a shell fell on the water's edge and
Completely destroyed the suction hose.
The marine sand consisted of a greyish sharp sand with shell
fragments, and towards the lower portion a considerable amount of
lignitized wood. At 22 ft., 30 ft., 40 ft., 44 ft., 50 ft. and 60 ft.
layers of clay (Polder) were encountered which were about 3 in.
thick, excepting that at 50 ft., which was about 6 in. in thickness.
These were passed through by continuing the percussion movement
Of the boring rods and the clay came to the surface in Small fragments.
They presented no difficulties in boring.
There was only sufficient 3-in. Casing to go to 50 ft., and from that
depth the I+-in. rod was continued downwards to the blue clay.
This could only be done by a continuous downward progress and
incessant pumping. After several attempts it was at last forced
down to the blue clay. The geological test boring set, with the I-in.
auger, was then used inside the Ił-in. pipe, and boring was continued
for IO ft. in the blue clay.
The blue clay was struck at 87 ft. and was typical Ypresian blue
clay. The complete section of this bore is shown on Fig. Ig. The
I}-in. pipe was Subsequently removed by using lifting jacks.
These bores showed the blue clay to be far too deep below the
surface to permit of the underground passage being constructed,
as the shafts would have had to have been about Ioo ft. deep.
I2. GEOLOGICAL REPORT ON COUNTRY N. AND E. OF PASSCHEN-
DAELE RIDGE.
In October of IOI7 a geological report, accompanied by a geological
map on a I/I60,000 Scale, and taken chiefly from the map prepared
by the Director of the Geological Survey, and reduced from the
I/40,000 maps of the “Carte Géologique de la Belgique,” was prepared
for the General Staff. This report covered the area from Nieuport
to Zeebrugge, and thence through Bruges and Ghent to Lille, Ypres,
Dixmude and back to Nieuport. The object of this report was to
explain particularly the nature of the surface of the country, and
what would result if that surface were broken by shell-fire to depths
of IO to I5 ft. This report dealt specially with the water conditions
in the soil, Subsoil and underlying geological strata.
36
For the purpose of this enquiry the Country was divided up as
follows:–
CLAY COUNTRY.
(I)
Blue Clay (a) of Roulers
region. (b) of Dixmude
region.
(2)
Clay, W. of Eccloo, and
E. Of Bruges.
(3)
Clay of Polders, Nieu-
port to Ostend.
SAND COUNTRY.
(4)
The Coastal Dunes.
*
(5)
The Ypresian Sands.
(Water-bearing.)
(6)
Dry Sands. (a) of top of
Passchendaele Ridge,
and (b) of the forest
region from Thielt and
SANDY CIAY COUNTRY.
(7)
Alluvials of the Lys Val-
Iey and of the Bruges
and Ghent areas.
(8)
High - level sandy clays
Of the Passchendaele
Ridge and of the re-
gion between Thielt,
Thourout and Bruges.
Thourout to Bruges. (9)
Alternating patches of
the sand and clay of
the Polders east of
Ostend and of the
Dutch frontier.
Shell-holes in this country were classed as follows:–
Those from which rain-water would drain away naturally—
4 and 6 ; and 5, 7 and 8 in part.
Those in which rain-water would remain until it became
evaporated—T and 2 ; and 5, 7 and 8 in part.
Those in which water would be permanent—3 and 9; and 5
in part.
The general conclusion was as follows : —
The country to the north and east of the present (October, 1917)
lines of the Allies, from east of Ypres to Nieuport, consists of two
long belts of plains —
(a) the Polder Plain, and
(b) the Lys-Bruges Plain, separated by the Passchendaele–
Hooglede Ridge, which expands into a low, wide platform
between Thielt and Thourout.
The Polder Plain, after much shell-fire, would be quite impassable.
Fair drinking-water could be obtained from its north-east half
between Ostend and Zeebrugge.
The Lys alluvial belt would have its surface affected by shell-fire
precisely like the country around Armentières and Ploegsteert.
In moving inwards from the two belts of plain towards the higher
ground enclosed by them, one would meet three clay areas,
respectively —
(a) around Roulers,
(b) east of Dixmude, and
(c) west of Eccloo.
In all these areas water would lodge in shell-holes after rain.
Shell-holes in (b) would be somewhat wetter than those in (a) or (c).
37
Above these clay areas come the wet Ypresian Sands. Wherever
their surface was broken by shell-fire, except where natural drainage
is specially good, water would lodge permanently in the shell-holes.
Still higher in altitude is an unreliable formation, in which wet
sands alternate with clays. The country from Messines to Hollebeke
may be taken as a type of this.
Lastly, crowning the Passchendaele–Hooglede and Staden Ridges,
and capping the higher portions of the low platform dipping from
Thielt to Bruges, are dry sands. These are a continuation of the
sands at the summit of Wytschaete. These areas are mostly Small
isolated patches, but they should be important as affording firm
dry ground.
On the whole, the country on the east side of the Passchendaele—
Hooglede Ridge, from the point of view of the effects of shell-fire on
it, may be regarded as very similar to that on the west side, but
while the Lys Valley alluvials would be passable after the surface
had been broken by shell-fire, that of the Polder area, under similar
circumstances, would be quite impassable, so that Our Own barrage
would stop our own progress. At the same time, in dry weather, the
clay area of the Polder country, provided its surface were not broken
by shell-fire, should be passable even for tanks, provided they could
clear the ditches.
The general geological structure of the part of the country referred
to above is shown on Plate I.
I3. GEOLOGICAL MAPS OF AREAS FOR DUG-OUTS IN FLANDERS
AND IN N. FRANCE.
While the work of testing the ground proposed for dug-outs, by
means of the light geological boring sets, had been proceeding almost
without intermission since May, IQI6, it was not until after the third
battle of Ypres that these boring operations assumed considerable
proportion, as many as IOO bores per week being completed about
this time. These were mostly put down by the Tunnelling Com-
panies who borrowed geological boring sets from the depôt at the
H.Q. of the Australian E. and M. M. and B. Company. Owing to
the demand for these bores it was found necessary to increase the
length of boring rods used by adding to the original total of 400 ft.
an additional 4,000 ft., a total of about IIO boring sets being provided.
This work was extended from Flanders, where conditions for dug-outs
were very uncertain, to areas like those of the Bois de Riaumont
and Bois de l’Hirondelle near Liévin, and Monchy-le-Preux, south of
the Scarpe, and to South-east of Arras, where the presence of water-
bearing tertiary sands made conditions for dug-outs uncertain.
Early in IOI8 test geological bores were made in the St. Quentin to
Noyon area, recently taken over by the British from the French.
In this area there was a considerable development of clay with
38
lignites (lignite et argile plastique) which was very unsuitable for
dugouts, observation posts, etc., and doubtful spots were thus
definitely tested.
The method was to enlarge the French geological maps on the
I/80,000 scale up to a I/40,000 or I/20,000 scale; and then distribute
Copies of these maps to the Chief Engineer and to the Controller of
Mines of the Armies concerned. It was in many cases obvious at
Once from the geological map that a particular spot was suitable or
unsuitable, as the case might be, for the purposes of dug-outs. It
was only in the doubtful cases that bores to a depth of about 40 ft.
each were made.
Twelve geological maps showing the relative suitability or other-
Wise of the ground for dug-outs, and based mostly on the Belgian
geological maps, partly on the results of the geological test bores,
were published at the Ordnance Survey at Southampton. These
embraced an area from Ploegsteert and Ypres to Staden, and to
near Dixmude of about 200 square miles. On these maps two primary
Colours were used, blue and red. Three shades of blue and three
Shades of red were employed, and two shades of purple. The
redder the formation as indicated on the map, the drier was it for
dugout, etc., purposes, and the bluer, the wetter. These maps were
widely distributed to the Second and Fifth Armies.
Geological maps, On a scale of I/40,000, enlarged from the French,
and Specially adapted to give information in regard to good and bad
ground from the dug-out point of view, were published of about
350 Square miles of country between Noyon and Lassigny and
Peronne, and about 330 Square miles on and around the Cambrai
plateau.
With the exception of the piece of the line between Festubert and
La Cordonnerie and Dixmude to Nieuport, geological maps for
dug-out purposes were published for practically the whole of the part
of the Western Front occupied by the British. Geological sections
of the entire front were published, as shown on Plates I., II. and III.
Plates IV. and V. show typical maps and section for the I/IO,000
Scale maps. p
In regard to the making of dug-outs and tunnels to the south of
Armentières, it will be seen from the geological section (Plate I.) that
between the Bois Grenier anticline and Neuve-Chapelle the conditions
are different, for the following reasons :—firstly, there is a thickness
of 8 to 15 ft. of water-bearing alluvials overlying the Ypresian clay
(blue clay), and secondly, the blue clays themselves, in which alone
in that area dug-outs and tunnels are possible, are in places So thin
that there is a risk of the subartesian water in the Thanet sands
under the blue clay bursting through the floors of the workings and
inundating them. In this area, therefore, a large number of geological
test bores were made partly by the 255th and I8Ist Companies, R.E.,
39
/
and partly by the 2nd and 3rd Australian Tunnelling Companies,
and the Australian E. and M. M. and B. Company. Where these test
bores showed that there was not more than about IO ft. of Overlying
wet alluvial and not less than 35 ft. of good clay below that, Con-
ditions were considered possible for dug-outs. That is, the whole
thickness of the strata down to the surface of the Thanet sands being
about 45 ft., more or less, the work would be carried on in this way :
Tubbing in segments, made of mild steel in rings of three sizes, either
6 ft, or 5 ft. 3 in., or 4 ft. 6 in. in diameter, was used. The complete
ring in each case was made up of three segments, each I ft. 6 in. in
depth. The horizontal flanges were made of angle iron riveted on
to the steel casing, while the vertical flanges were formed of the
turned-in edges of the steel plate of the casing itself. At the joint
where the vertical flange met the horizontal there was a good deal of
leakage, which was very difficult to stop. In the later types of
tubbing it was always specified that the vertical flange was to be
welded to the horizontal flange at each joint. This was effective in
stopping any serious leakage. The lowest segment of the tubbing
was provided with a cutting edge of cast iron, and the tubbing was
forced down either by weighting or jacking, or both. It was taken
far enough into the clay to make a secure watertight joint and sinking
was continued in the clay until a depth of about 35 ft. from the
surface of the ground was reached. The space for the dug-outs was
now excavated to a height of about 7 ft., so as to leave about 28 ft.
Of cover. In the case taken, where the Thanet sands surface was at
45 ft. below the Surface of the ground, there would thus be a thickness
of IO ft. of blue clay below the floor of the dug-out. Mosſ of these
dug-outs required a little pumping in order to keep them dry. The
water did not, as a rule, weep in from the floor or from the roof, but
leaked at the joint between the bottom of the tubbing and the blue
clay or from between the joints of the tubbing. It was allowed to
Collect in a Sump close to the bottom of the shaft, from which it was
pumped to the surface. The tubbed shafts were usually provided
with a spiral staircase. Thus the men in the dug-outs between
Jay's Post, near Fleurbaix (south of Armentières) and Neuve-
Chapelle were sandwiched in between the water-bearing sands
of the Lys River alluvials above and those of the Thanet sands
below.
It was at One time proposed to bore from the floors of the dug-outs
down through the IO ft. or so of blue clay into the Thanet sands
below, and then fix a standpipe in the bore with a tap, so that fresh
artesian water would be available for drinking and cooking purposes
for the men in the dug-out, but the proposal was abandoned, as it
was feared that the artesian water might force a passage for itself
along the junction line of the outer surface of the Standpipe and the
blue clay and so inundate the dug-out.
40
I4. CRUSHING OF DUG-OUT TIMBERS IN YPRESIAN CLAY.
An important feature in connection with these dug-outs made in
the Ypresian clay (blue clay) was the question as to why the timber
of dug-outs and galleries in blue clay so often became crushed in at
depths of only 28 to 30 ft. below the surface. The point chiefly at
issue was as to whether the crushing of mine and dug-out timbers
Was due to :—
(a) the swelling of the clays,
(b) top pressure—the clay behaving as a more or less rigid body, or
(c) both top pressure, side pressure, and, to some extent, bottom
pressure—the clay behaving as a viscous fluid.
As regards the crushing of mine timbers, it was often found that
9 in. × 3 in. Baltic on the flat was crushed after a few months or
less, both legs and cap pieces giving way. The vertical pressure on
9 in. × 3 in. legs with a cap-piece 9 in. × 3 in. and 3 ft. long would
be approximately a little over 3 tons. On the assumption that the
whole pressure on the cap-piece is transmitted to the legs, and that
the legs remain absolutely vertical, they should be capable of sustain-
ing about 18 tons. But, as a matter of fact, they do not remain
absolutely vertical for any long period, even if they were originally
placed in an absolutely vertical position. The slightest movement
of the clay at the sides of the legs pushes them out of the true vertical,
and at Once their ability to sustain the load lessens enormously. The
legs become more and more bent under the vertical pressure and
lateral pressure until they snap. If there are many cleavage planes
in the drier part of the clay, the tendency for the timber to yield
under the load is increased. The presence of sand in the clay greatly
increases its stability. In pure Sand no crushing of mine timbers is
usually experienced. The Director of the Geological Survey,
London, states, in reference to the alleged swelling of Clay, that no
chemical action of importance can take place, at all events rapidly,
in this type of clay when exposed to the air of a mine gallery. He
thinks that, under the circumstances, the clay is more likely to
become desiccated and so to shrink. On the Other hand, Some
O.C.’s of Tunnelling Companies maintain that the dry clay is hygro-
scopic, and absorbs moisture from the air and that this hydration
causes the clay to swell. Certainly the dry clay of a freshly exposed
face at the end of a mine gallery often starts to Crumble down. This
seems, on the whole, to be due to absorption of moisture. It is
possible, therefore, that in the first stages a slight swelling takes
place of the clay in the sides of a gallery—just enough to slightly
bend the legs. Then top pressure transmitted Sideways by the
viscous state of the clay, aided perhaps by joints in the clay, does
the rest. Top pressure transmitted Sideways seems the main
factor,
4I
Certain measures can be taken to mitigate the trouble of the
crushing in of mine timbers and dug-out timbers by clay pressure, e.g. :
(i) In the first case, no more clay should be taken out than is
absolutely necessary to make room for the timber sets, so
that no hollows are left such as encourage the clay " to get
a move on.’’
(ii) Every caution should be taken to stop or diminish side
pressure. Side pressure, if sufficient to bend the legs of the
sets, changes the conditions for the legs, So that they no
longer act as columns but as beams, and thus they become
inadequate to sustain the top pressure, which is the principal
pressure.
(iii) Much side pressure may be avoided, not only by taking the
above precaution, but also by always spacing parallel
excavations, such as dug-out chambers, in such a way that
the pillars separating them from one another are never
less than 40 ft. wide. If they are less, side pressure is sure
to develop.
(iv) Side-pressure may be reduced by spacing the timbers, in the
case of ly of temporary galleries and as a measure of economy,
when timber is scarce. In this case, the clay works through
the openings in the timber and has to be shaved off from time
to time as fast as it projects from the walls of the galleries.
Side-pressure is reduced by this method, just as “weep-
holes '' take off the water pressure against the inner surfaces
of retaining walls. The great objection to this system
of leaving spaces between the timbers is that it allows the
clay to move, and, Once the movement is started it is very
hard to stop it, and obviously it involves a certain amount
of Constant labour in cutting away and removing the clay
as fast as it forces its way between the timbers.
(v) In view of the fact that clay behaves as a very viscous liquid,
in the matter of exerting pressure in all directions on
hollows, such as dug-outs, the legs of sets should be regarded
as beams rather than columns, and should be made strong
enough to sustain a pillar of clay equal in height to the
depth of the dug-out below the surface—that is, if the top
of the dug-out is 30 ft. below the surface, and the dug-out is
6 ft. high, the maximum pressure per square inch on any
leg of the sets would be about equal to that of a pillar of
clay 33 ft. high, that is, a pressure of about 31 lbs. per
square inch. If the whole of this pressure were transmitted
as a load distributed uniformly over the 6 ft. × 9 in. x 3 in.
legs, regarded as beams, the timber on the flat is only able to
sustain a pressure of I,500 lbs. per foot run (= 1.4 lbs. per
42
Square inch), whereas the load on the 9 in. × 3 in. timber
on the flat would be about 3,342 lbs. per foot run (= 31 lbs.
per square inch). It is the case that on edge the 9 in. ×
3 in. timber Sustains about three times the pressure that it
would on the flat, that is, a pressure, when on edge, of
42 lb. per Square inch. Strong close supports should there-
fore be put in always, and, certainly in the case of all
horizontal excavations, these should be placed in a vertical
position.
In regard to what thickness of timber is really sufficient to with-
stand clay pressure of this amount, it has been the experience at
Messines South that galleries under 30 ft. of clay (in this case
Paniselian clay) broke Baltic legs and cap-pieces of sets 6 ft. 6 in. ×
3 ft. made of 9 in. × 3 in. timber on the flat. In the calculations
just given it is shown that 9 in. × 3 in. timber on edge is equal to
resist the maximum possible theoretical pressure that a free prism of
Clay 33 ft. high can exert. Such timbering, although absolutely safe,
is very costly.
A Tunnelling Company Commander, who had a wide experience in
tunnelling in Ypresian clay, both at London in the London Tube
System, and in Flanders, states that at Arbre, near St. Julien, in the
Ypres salient, where the clay is very hard and compact and also very
dry, 3-in. legs on the flat will not stand for more than two or three
days, and 5-in. legs on the flat show signs of pressure within a week.
“These have now been replaced by 9 in. × 5 in. timbers on edge
close setted, with the result that the caps are now bending under the
top-pressure. . . . At Pheasant Trench everything points to top-
pressure as being the greatest. In this system side-pressure is
brought about by an insufficiently thick pillal (20 ft. thick) between
the dug-outs. In this case, where a leg has been strong enough to
withstand top-pressure, it has sheared the cleat off the sill and
kicked out at the bottom from side-pressure alone. But where the
pillar of clay between the dug-outs is some 50 or 60 ft. thick, as is
the case with the Small dug-outs, the legs Only bend, under top
weight.”
Another Tunnelling Officer suggests that in heavy clay ground,
with a cover of about 30 ft. —
(a) Galleries should be close-timbered, with legs of at least 6 in. ×
3 in. timber on edge and double-top sills;
(b) Dug-outs in heavy clay ground, as above, should preferably be
of the “corridor ’’ type with steel sets close-lagged at I-ft.
to 2-ft. Centres.
In each case he is, of Course, assuming that the galleries and
dug-outs are to be permanent.
43
The fact may here be emphasized that if dry sand with Sufficient
cover can be obtained, it is far preferable to clay, for two reasons –
(i) Shell penetration in sand is less than half what it is in clay ; and
(ii) Sand in the roof of a gallery or dug-out “bridges' far better
than clay, particularly if care be taken that the sand does
not start running.
Therefore, the timbering of dug-outs and galleries in Sand need be
only of a comparatively light description, as :-
(a) They have less than half the over-burden to carry that clay
has (as I2 to I5 ft. of Sand is as adequate protection against
shell-fire as 30 ft. of clay), and
(b) Sand is a far more effective “bridge " across any excavated
chamber than clay is, as sand does not flow like clay, but
the sand grains grip One another and So, by their bridging
action, reduce top-pressure to a minimum.
y
An interesting case of geological Conditions affecting dug-out work
occurred at the Scherpenberg, near Mont Kemmel, on 17th May,
I917. The whole situation is illustrated on Fig. I4. The tunnels
A and B were driven into the hill, with a view to constructing a
series of dug-outs between them, as soon as a sufficiency of cover
had been reached. The two tunnels were only about 95 ft. apart
from one another and started at the same level, and the strata in
which they were driven were practically horizontal ; and yet, while
tunnel A encountered only dry sand, tunnel B started in clay, and at
a distance of 65 ft. from the entrance struck running sand containing
so much water that the continuation of this tunnel was impracticable.
A geological examination showed at Once that there was either a
fault with a strong fold, or more probably, as shown on Fig. I5, two
step faults. The total amount of throw of the two faults was
determined at about 40 ft. The trend of the faults was determined,
and suggestions made for excavating the dug-outs off tunnel A (after
it had been extended into the hill to a considerable distance further)
in such a direction as to avoid the faults. This work was satis-
factorily completed later.
It is difficult to estimate the total number and length of the
geological test bores, for dug-outs alone, put down along the British
part of the Western Front, but they were certainly well over I,000,
their total length (the general depth being about 35 ft.) aggregating
about 35,000 ft.
I5. SOUTERRAINS.
In the northern part of France, in the chalk country, there exist
very numerous “SOuterrains,” Otherwise known as “bores '' or
“muches.” Mostly these are what may be termed “mine quarries.”
44
They have been made, for the most part, for the purpose of obtaining
the most durable type of chalk for building purposes : near the
surface the chalk is much splintered and softened by weathering
and is unsuitable for building purposes, but by sinking to a depth of
50 ft., more or less, a tough unweathered type of chalk can be
obtained. This was the primary motive which prompted the French
in the middle ages, and indeed down to the present time, to mine
their chalk rather than work it in opencast quarries. A secondary
motive was the desire to conserve the surface of the ground.
Access to the souterrain was given either by adits or by inclines
With steps, or spiral stairways, or vertical shafts often bell-mouthed
at the bottom. Sometimes access was obtained through a local
well.
Frequently the entrance to the souterrain was from a spiral stair-
case descending at the west tower of a church (see Fig. 15, Type A,
Gapennes). Sometimes it was from the cellar of a château or other
large building. In some cases the stone was quarried on a regular
Plan, like that of the stall and pillar used in coal-mining ; but more
frequently it was irregular, as in the famous caves of Arras (Fig. I5,
Type B). In the Middle Ages many of these souterrains were used
as refuges by the local inhabitants in the turbulent times when the
Country was overrun by the Spaniards and other enemies. The plan
On Fig. I5 shows a large number of towns and villages in Northern
France possessing souterrains. It is interesting to note that the
Souterrains of Arias are excavated out of just the same layers of
chalk as those of Montreuil. Large numbers of our troops were
accommodated in these souterrains, which afforded very secure
COVer.
There were at least a hundred of these souterrains in the area
Occupied by the British Army, but probably not more than about
twenty were occupied at any one time. Several of these were
Ventilated by means of an ancient type of airhole (“Soupirail").
I6. VENTILATION AND DRAINAGE OF DUG-OUTS AND SOUTERRAINS.
Ventilation.—Where possible, the ventilation of dug-outs was im-
proved by making vertical or oblique 6-in. bores by means of the
“Wombat '' boring machine. The chief use of this type of boring
machine On the Western Front was for the above purpose, and it was
Only occasionally that they were employed on bores for water, on
bores for demolitions, and bores for testing geological conditions.
Geological examinations had, in several cases, to be made before
the bore for the ventilating hole was commenced.
Many thousands of such ventilating bores were made.
In case of gas attack they were closed by means of a mop of the
“Turk's Head '' type, made of rags fastened to the end of a
45
short pole. By this means the ventilating hole could be quickly
plugged.
Drainage.—As regards the drainage of dug-outs, trenches, etc.,
geological advice was occasionally sought. “Wombat " bores were
used for draining the trenches at Cuinchy and in part of the Ypres
salient. In the case of water being held up at the bottom of trenches
or of dug-outs by “clay with flints"—a very widely distributed
formation in the chalk area—sink-holes were dug or holes blown by
means of small charges of explosive.
These holes opened a passage for the water through which it
escaped into the chalk. The clay with flints was usually not more
than from 3 to 5 ft. in thickness, but was sometimes over IO ft. thick.
In cases where the thickness was considerable, so that drainage was
difficult, it was easier to excavate the dug-out altogether under the
clay than to place it above the clay and then construct a number of
deep drainage holes through the clay into the chalk. This was done
particularly in the case of the dug-outs on the G.H.Q. line to the north
of Rubempre, about eight miles S. by W. from Doullens.
I7. TANK MAPs.
These were prepared by the Tank Department itself, certain
points only being referred to the geologists, and “Tanks" being
furnished with the maps published by the geologists, showing
geological conditions for dug-outs and Some details of surface soils and
subsoils in areas invaded by the enemy, in advance of the British.
Had more geologists been available, detailed work could have been
done on these maps. Geological considerations were frequently of
considerable importance from the point of view of the possibility of
moving tanks over the ground. Fig. I6 shows a number of Tanks
bogged in the soft sandy clay of the Paniselian formation to the east
of Ypres.
I8. FOUNDATIONS.
(i) Bridges.
(a) For Building.—During the latter part of the rapid advance
of the British troops in September, October and November a
series of geological reports were prepared by Lieutenant Hills on
the possibility, or otherwise, of using piles in the building of new
bridges over the Meuse between Givet and Vise, over the Sambre,
the Escaut, the Dendre, the Mons-Condé Canal, the Blaton Canal,
the Charleroi-Brussels Canal and the Canal du Centre, in the
event of the bridges then existing being destroyed by the enemy.
These reports wele based on the information deducible from the
I/40,000 geological maps of Belgium lent by the Director of the
Geological Survey, London.
46
(b) For Demolition.—As a precautionary measure at a time
when the enemy was threatening an attack on the Channel ports
in IQI8, the nature of the foundations of the abutments of the chief
bridges in the part of Northern France in British occupation, were
tested by means of the light geological boring sets. One hundred
and twenty-five bores were made for this purpose, and records kept
Of the strata penetrated.
(ii) For Heavy Machinery—Bores for this purpose were put down
at Beaurainville in the Canche Valley.
(iii) Dams.-Geological information was given in a few cases on
this subject.
CHAPTER III.
DESCRIPTION AND USE OF BORING PLANTS FOR
GEOLOGICAL TEST BORES.
I9. GEOLOGICAL BORING SETS.
(See Plate VI.)
(a) Description of Apparatus.-The original -in. (O.D.) Solid steel
boring-rods brought from Australia were gradually replaced with
!-in, gas-pipe, the latter having greater rigidity and less torque than
the former.
The boring-rods consist of #-in. gas-pipe cut to 3-ft. lengths and
threaded at both ends with #-in. pipe-thread. A k-in. Socket is
screwed to one end of each length of ,-in. rod.
The augers used are twist augers of I-in. and 2-in. diameter. The
length of the I-in. augers is 3 ft. and that of the 2-in. augers IS in.
The pitch of the 2-in. augers is 3 in., and that of the I-in. auger
2 in. The cutting end of both is finished off in fish-tail shape and
is spread to measure I; in, and 2% in. respectively, to ensure adequate
clearance for the remainder of the auger. The upper end of the augers
is provided with 4-in, pipe-thread on which is screwed a #-in. Socket.
This enables the socketed end of each boring-rod to be uppermost,
which is of advantage in that it decreases the risk of losing rods
down the hole by slipping through the jaws of the Trimo or Stillson
wrenches, as explained above.
The handle for turning is in the form of a T piece, the horizontal
portion, being 2 ft. in length. The vertical portion is about 6 in. in
length and is provided at its end with -in, pipe-thread which fits
into the socket at the upper end of the boring rods.
The Casing Consists of I}-in. pipe in 3-ft. lengths, threaded and
socketed similarly to the #~in. pipe. A câlyx cutter with four cutting
teeth is provided to fit to the bottom length of casing, to act as a
cutter in working the casing downwards. For turning the casing a
clamp with handles is provided which bolts round the outside of the
I}-in. pipe.
A small sand pump which can pass inside the Ił-in, casing and
which is fitted with a ball valve is designed for dealing with running
Sand.
• A recovery tool is provided for recovering the #-in. rods in case of
their being lost down the hole. The tapered male thread is designed
to engage into the female thread of the uppermost socket of the
lost rods.
47
48
A hinged clamp for eliminating the risk of the dropping of the
*-in, pipes down the hole while being disconnected is shown in
Plate VI.
For handling the pipes in screwing and unscrewing, footprints
or Trimo or Stillson wrenches are provided. For the 3-in. pipe
9-in, footprints are satisfactory, but at least 12 in are required for
the Ił-in. Casing. It is preferable, however, to use I4-in. Stillson
wrenches, which suffice for both the g-in. and the ri-in. pipe.
Each Geological Test boring set, as used on the Western Front
during I917 and IOI8, consisted, therefore, of the following :—
I3 lengths of 3-in. rod, each 3 ft. long.
I length of $-in. rod, 2 ft. long.
I length of $-in. rod, I ft. long.
4 lengths of I}-in. Casing, each 3 ft. long.
I length of Ił-in. Casing, 2 ft. long.
I length of Ił-in. Casing, I ft. long.
I I-in, auger, 3 ft. long.
I 2-in. auger, I ft. 8 in. long.
I Calyx cutter for Ił-in. casing.
I recovery tool.
I hinged clamp for $–in, rods.
I handle for $–in. rods.
I clamp for Ił-in. Casing.
2 I4-in. Stillson wrenches.
The total weight is 93 lb.-It can be comfortably carried by two
men, and can be used without attracting the attention of the enemy,
even in the front trenches.
(b) Method of Boring. The principal boring tools are the 2-in.
and I-in. twist augers. Boring is started with the 2-in. auger and
the #~in. rods. This is continued until a depth of about 15 ft. is
reached or further progress is impossible owing to the hole caving in.
In this latter case, the requisite length of Ił-in. Casing is joined up
with the Calyx cutter at the bottom end. Immediately the 2-in.
auger is withdrawn, the casing is inserted and thrust down to the
bottom of the hole.
The 2-in. auger is then changed for the I-in. auger which fits within
the I+-in. Casing, and boring is continued. If the Strata passed
through continue to consist of water-bearing Sand or Sandy clay
which persists in closing in as the auger is withdrawn, the clamp is
fitted to the casing, and by a combination of revolution and down-
ward pressure, thrust downwards in accordance with the progress
boring with the auger. This is continued until material is met with
sufficiently solid to admit of its being bored through without the
help of casing. Boring is then continued with the I-in, auger.
If, however, running sand is encountered, the Casing, when
49
inserted, is forced down some distance—say I or 2 ft., if possible—
and the sand thus enclosed within the casing is then removed by
means of the sand pump. It is preferable, however, to continue
using the augers as long as the sand can be withdrawn thereon.
If boring is being carried out in trenches which are under enemy
observation, it is necessary to disconnect the boring rods at every
3 ft. whenever they are withdrawn after an auger-length has been
bored. The same thing applies in the case of boring in a dug-Out Or
a mine gallery. Occasionally it has happened that a trial bore has
been located at the bottom of a shaft, in which case there is no
necessity to disconnect the rods, the whole length of which can be
hauled up the shaft. If the bore site is located beyond enemy
observation the rods may be disconnected in withdrawing at every
I5 ft., that being the maximum length which can be handled without
bending the rods.
In boring clay care must be taken that the auger is not forced so
far as to anchor itself. This may be guarded against by boring for
about 6 in. and then lifting about I in. In this way the thread of clay
around the auger is broken and thus the auger is kept free in the hole,
and when the auger-length has been bored the auger can be removed
without any difficulty. This particularly applies to the I-in. auger,
3 ft. in length. Originally the length of the I-in. augers was about
I5 in., but it was found by experiment that if the auger is kept free, in
the manner described above, the 3-ft. length can be used with safety.
This saves time, as the greater portion of the time occupied in putting
down a bore is taken up with screwing and unscrewing the rods. This
particularly applies to boring in the front-line trenches, in dug-outs
and in mine galleries.
When disconnecting the #-in. rods, it is advisable to pass them
through the hinged clamp to minimize the risk of their slipping
down the hole.
The 2-ft. and I-ft. lengths of Ił-in. and #-in. pipe are provided in
Case of boring in a dug-Out or mine gallery where headroom is limited.
In a mine gallery 4 ft. in height the shorter lengths admit of the
application of downward pressure while boring is in progress. This
would be impossible if only 3-ft. lengths of boring rods were available.
At times also, where the casing has to be forced through a clay bed,
to deal with an underlying water-bearing bed, it may be necessary
to force the casing down by means of “jacks.” Ordinary lifting-jacks
are used for this, thrusting against the roof of the gallery or dug-out.
In removing the casing thus forced down by jacks, it will be necessary
to use the jacks again by lifting against the clamp employed for
turning the Casing.
For lifting the #-in, pipe with the auger full of clay as depth is
gained it is desirable to place two lengths of the 13-in, lining pipe
under the handles of the T piece, as close to its centre as possible.
D
50
The lifting is then done by the four men, one at each end of the 13-in.
pipe. This method gives free action to four men and lessens the risk
to the handles of the T piece, which otherwise are apt to be bent
upwards in the process of lifting.
(c). Rate of Boring and Number of Men Required.—The rate of
boring depends on the geological character of the strata, and on
whether it is carried out under conditions which —
(i) Necessitate connecting the rods every 3 ft., or
(ii) Which allow of disconnecting at not less than 15 ft.
Under the most advantageous conditions, where the strata consist
of Sandy clay or clay which does not need casing and where there is
Complete freedom from enemy observation, a 40-ft. bore can be
Completed in about three hours. Two 40-ft. bores can be put down
without any difficulty in a working day. This work becomes
progressively heavier and slower with depth, and whereas a 20-ft.
bore can be completed in less than one hour, the second 20-ft. takes
about twice that time.
Where casing has to be used, a 40-ft. bore may take up to eight
hours in difficult ground, but this is quite exceptional, and it is most
Often possible to put two such bores down in a working day.
The number of men required to work one plant is four. The work
of turning should be done by one man alone, but the four men are
required for lifting ; as the hole gets deeper there is always
considerable resistance to the withdrawal of the auger and rods,
and it is this maximum load which necessitates the presence of the
four men, two only of whom are required for the Operations other
than lifting.
2O. MODIFIED “ ACME '’ BORING SET.
(See Plate VII.)
Description of Apparatus.-The boring rods consist of I-in. gas-pipe
cut to 3-ft. lengths and screwed at both ends with I-in. pipe-thread.
A 1-in. socket is screwed to one end of each length of I-in. rod.
The boring-tool is what is known as a Skeleton Bit, which is shown
in Plate VII. It has a cutting edge of 3 in. in width. For boring
ventilation holes a 6-in, cutting edge is desirable. The projecting
point beyond the cutting edge is from I in. to Ił in. long, the sides
being left square. The cutting edge is taped to a knife edge. The
bit is 3 ft. in length and screwed at the top end with I-in. pipe-thread
and provided with a 1-in. socket. The chisel bit, with 3-in. Cutting
edge, is 4 ft. long, and is similarly screwed and socketed at the other
end.
The column is that of the “Acme "Boring Outfit shortened to 4 ft.
by cutting a length of 1 ft. off the lower end and refitting the base-
piece to the shortened column. The head contains an adjusting
5I
screw by which the column can be lengthened by about 6 in., and thus
thrust and firmly fixed between the roof and floor of a gallery or
dug-out.
The feed-screw is the feed-screw of the “Acme " Boring Outfit,
provided at each end by enlargements welded on at both ends of the
Screwed portion which are turned down in the lathe and threaded
with I-in. gas thread.
The ratchet handle is that of the “Acme " Boring Outfit without
any alteration.
The sand pump, shown in Plate VII, consists of 2-in. pipe, 3 ft.
in length, fitted at the bottom end with a brass ball valve. This is
Screwed inside the 2-in. pipe. The internal part is tapered towards
the top to allow the I-in. brass ball to exactly cover the orifice around
which a seating is ground for the ball. The top end of the sand pump
is provided with a handle to which can be attached the rope for raising
and lowering it in the borehole.
Each modified “Acme " Boring Set, as supplied during IQI8,
consisted of the following —
I2 lengths of I-in. pipe, each 3 ft. long.
2 lengths of I-in. pipe, each I ft. 6 in. long.
I Skeleton Bit with 3-in. Cutting edge, 3 ft. long.
I Chisel bit, 4 ft. in length.
I Column.
I Feed Screw.
I Ratchet handle.
I Sand pump.
50 ft. §-in. rope.
2 Stillson wrenches.
The total weight is I50 lbs. It can be carried without any trouble
by three men.
Method of Boring.—To set up the apparatus, an excavated space
about 4 ft. Square is required. In mine workings or a dug-out this is
easily available, the length of the column being cut down to 4 ft. for
the express purpose of convenience in working in mine galleries.
For a vertical downward hole the column is set up horizontally
about 3 ft. from the floor and fixed in position by means of the
adjusting Screw, by thrusting against Slabs of timber on the sides of
the excavation or gallery. The Column is so placed that its centre
is vertically above the proposed borehole.
The latter is started for a few inches by hand, using the chisel bit.
The skeleton bit is then Screwed on to the feed screw and the latter
placed in the sliding sleeve of the column. The sliding sleeve is left
loose until the skeleton bit is in a vertical position, when it is screwed
tight and boring started by attaching the handle to the top end of the
feed-screw. If the complete revolution of the handle is impossible,
52
owing to confined space, the ratchet attachment may be used. Water
is poured down the hole as boring progresses, sufficient water being
used to produce a slurry which can be conveniently handled by the
Sand pump.
When the length of the feed-screw has been bored it is uncoupled
and reversed, and then connected to the skeleton bit again and boring
continued. The object of having the feed-screw provided with the
I-in. thread at each end is thus seen, for by being able to simply
reverse it, the time which would be taken in turning it back to its
Original position is thus saved.
Boring is continued until the accumulation of slurry is sufficient
to interfere with boring, and the rods are then uncoupled from the
feed-screw and the sliding sleeve run along to the end of the column
and the rods then withdrawn. The sand pump is then lowered by
the rope and the hole completely cleared of slurry. The skeleton
bit and rods are then replaced and coupled to the feed-screw, but the
sliding sleeve is not screwed up tightly. Boring is started and after
a few turns the sliding sleeve will have adjusted itself in relation to
the rods, and is then screwed up tightly. In this way the Original
direction of the hole is retained, as the sliding sleeve automatically
resumes its original position.
If flints are encountered, the skeleton bit is replaced by the chisel
bit and boring continued by percussion. The fragments of flint
mixed with the chalk slurry are removed by means of the Sand pump.
If a vertical upward hole is to be bored the column is fixed
horizontally about 3 ft. from the roof, in a similar manner as
previously described. Boring is done with the skeleton bit, but water
is not added because the spoil from boring falls away from the cutting
edge, leaving the latter always free.
Horizontal holes are more difficult.
The machine is set up, as before, about 3 ft. from the face to be
bored. Water is difficult to feed and the spoil cannot be removed
by means of the sand pump, but a scraper at the end of #-in. Solid
rods must be employed. In fact, this apparatus is not designed to
bore horizontal holes, but only vertical Ones. Horizontal holes are
best bored by means of the “Wombat "Boring Machine, which was
specially designed for that work.
Rate of Boring and Number of Men required.—With the plant as
described and used above, a vertical downward hole can be put down
for a depth of 70 ft. in fifteen hours, and a 40-ft. hole in eight hours.
The number of men required to work the plant is two.
A vertical “upper "hole was put up 30 ft. in three and a half hours.
The machine takes eight minutes to erect ready for boring.
In the experiments on which the design of this plant was based
it was found that the augers, as supplied with the “Acme " Coal-
boring Machine, were inferior in speed of boring in chalk to the twist
53
augers used with the geological test-boring set described above.
Further experiments, however, showed that the skeleton bit was
infinitely superior to either of these, and after exhaustive tests, was
adopted as the most desirable type of bit for boring in the chalk.
The combination of continuous downward pressure with the
revolution and the cutting effect of the auger supply the requisites
which were found to be necessary when boring in chalk with the
hand test-boring plant.
2I. THE “WOMBAT '’ BORING MACHINE.
The No. 1 Australian Mining Corps brought with it thirty-six
geared boring machines operated by hand and capable of boring
at any angle from horizontal to vertical. They were Specially
designed for putting in horizontal bores, 6% in. in diameter for
demolition work in Gallipoli. A description of these boring machines
is given elsewhere in mining notes. They were designed entirely
by Captain Stanley Hunter, of the Geological Survey of Victoria,
Australia. They were used on the Western Front for boring for the
following purposes —
(i) For demolitions.
(ii) For boring ventilating holes for dug-outs. This was their
principal use.
(iii) For boring for water.
(iv) For putting down deep geological test-bores.
The following description of the “Wombat '' machine and method
of working it is taken from mining notes No. 73 :—
The “Wombat '' type of hand-operated boring machines, brought
over by the Australian Mining Companies, have been tested in chalk
and clay with satisfactory results. The plant can drill a hole of
6% in. diameter Over 200 ft. in length, at an average speed of 3 or 4
feet per hour in chalk, or 4 to 6 feet per hour in clay.
The opportunity for using long holes of this size, carrying about
II lbs. of explosive per foot, has not frequently arisen. But their
service is likely to develop with the general increase of offensive
operations. They can be used in soil unsuited for push-pipe
operations and allow a greater latitude for variations of depth.
Like the push-pipe, the “Wombat '' is described as a “weapon of
opportunity,” and it is essentially offensive.
(a). General Features.—The plant can either be erected on a wooden
sledge or bedplate, with the Columns, carrying the gearbox and feed-
screw, Supported by back stays ; or else rigged up in an underground
chamber, like a machine drill, jacked to the roof. The chamber
required must be 7 ft. long, 6 ft. wide, and 5 ft. to 5 ft. 6 in high,
with gallery space in front and behind for control of rods.
The weight of the machine, including wooden bedplate, is 360 lbs.
54
When dismantled for transportation to trenches, it is an eight-man
load, without pump, hose, cutters, rods, etc. The heaviest part
can be handled by two men.
The rotation of the rods is actuated through bevel-gearing by
drive handles on each side of the machine, allowing four men to
work. The feed-screw, with maximum advance of 14 in. at each
fleet, passes through a sleeve feed nut controlled by a rotating
wheel. If the wheel is fixed, the feed screw advances at the rate of
one turn, or 4 in. for each rotation of the drive handles. This speed
can be exceeded or reduced by rotating the sleeve feed nut in the
opposite or in the same direction as the feed screw. As with push-
pipe Operations, there is a tendency for holes to rise.
(b). Drill Rods and Cutters.-The hollow drill rods, through which
water is served by a small hand pump to the cutting edge, are I; in.
diameter, and in 5 ft. lengths.
In clay or Soft to medium chalk a spiral auger, 2 ft. long, with
detachable bit, is used, followed by two 5-ft. lengths of twist rods.
An advance of up to IO ft. may be made for each withdrawal.
In hard chalk, 6-in. Calyx Bits (cylindrical) with a 3-ft. or 6-ft.
Core barrel are used. Under favourable conditions, an advance of
7 ft. may be made for each withdrawal of rods. When flints are met,
normal progress becomes impossible. It is necessary to draw back
the rods about a foot and then drive them as sharply forward as
possible to crack the flints, before revolving the bit. Speed in flinty
ground may fall to I ft. per hour and the work is, of course, noisy.
The core barrel becomes filled with solid core, chips and slime,
according to the character of the chalk.
(c). Organziation for work.-A boring Squad consists of an N.C.O.
and seven men. Four men are on the drive handles, and one at the
chuck, screwing and unscrewing all rods and bits and generally
controlling the operation of the machine. The two other men are
on the pump, hose connections, and Odd jobs. *.
Water requirements vary widely with the rock or soil. In a recent
test at the First Army Mine School, sixteen gallons per hour were
used over a long run.
(d). Speed of work.--Three holes were recently bored in chalk at
the school with the following results —
(i) Length of hole, 232 ft. total working hours, 58 hours;
Average speed, 4 ft. per hour. (I7 feet of flints and 5 ft.
of mixed flint and chalk were passed through).
(ii) Length of hole, 178 ft. , total working hours, 59 hours;
Average speed, 3 ft. per hour. (40 ft. of flints and IO ft.
of mixed flint and chalk.)
(iii) Length of hole, I66 ft. , total working hours, 52 hours ;
Average speed, 3 2 ft. per hour. (20 ft. of flint passed
through.)
55
In addition a long hole was bored in July on the front of
the 251st Co., R.E., in clay.
(iv) Length of hole, 194 ft. ; Speed of drilling, 4.5 ft. per hour.
The entire operation, including the cutting of the chamber, forward
gallery, etc., under difficult conditions, was eleven days. The hole
was started at a depth of I2 ft., and may have risen towards the end.
A charge of 150 lbs. was fired in three 53-in. diameter cylinders.
The above bore was made on the Cuinchy part of the Western
Front, near the “ Brickstacks '' to the South of the La Bassée Canal.
The explosion of the torpedo cartridges satisfactorily demolished
the enemy outpost, which was the objective.
At the taking of Vimy Ridge on April 9th, IOI7, the Opening up
of deep explosion trenches across “No Man's Land '' by means of
horizontal bores made with the “Wombat '' was quite Satisfactory,
as already described.
On two special occasions the “Wombat '' was used at Hill 70,
Loos, for offensive demolition during IOI7. Owing to the
phenominal rise of chalk water-level one of our mine chambers
became inundated as well as the gallery connected with it, and the
electric leads became damaged so that the mine Could not be fired.
An enemy's tunnel was approaching this mine, and it was a matter
of urgency to blow the mine. A “Wombat '' bore was put in and
reached the mine chamber. A 5-in. cartridge containing amonal was
then pushed to the end of the borehole and fired, and the mine was
detonated satisfactorily. On another occasion it was ascertained
that near the same spot the enemy was in the act of charging one of
his mines. The No. 3 Australian Tunnelling Company bored rapidly
with a “Wombat '' Q7 ft. through hard chalk with a good deal of
flint, at a depth of over IOO ft. below the surface and reached the
charge of the enemy's mine. A cartridge was then inserted and the
enemy mine blown. These two blows very much relieved the enemy
mining pressure on this part of the front.
For purposes of ventilation there was so much demand for these
machines that, in addition to the original 36, 50 more were constructed,
and were more or less constantly in use at the front for this purpose.
Experiments made at the Third Army Mine School showed that
for short bores for ventilating purposes, of 50 to 60 ft., when account
was taken of the time needed for installing the respective drills, the
modified “Acme " could beat the “Wombat" for speed, provided
the chalk was Soft, but for hard chalk with flints the “Wombat ''
with Calyx barrel is probably the best type of machine for the work.
“Wombats '' were also employed in Flanders to bore for water
through the Ypresian sands, but as the depth of the bores was 250 ft.
to 300 ft., and the clay was extremely tough, the machines were
Somewhat Overtasked, and for the remainder of the bores in this
area more powerful drills, like the “Star" or the “Keystone" or
56
the “ Hunter" drill were employed. To a limited extent the
"Wombats" were also used for draining trenches, and for making
horizontal bores for burying Signal wires, etc. The latter was done
in the Nieuport area, between Nieuport and Wulpen, the bore
following the bank of the canal at 8 ft. below the surface of the ground.
Over 2,000 ft. of boring was made for this purpose. To a limited
extent the “Wombat '' was used at Vimy Ridge for geological test
Purposes, where by its means the soft clays were located at 150 ft.
below the surface, in which a deep tunnelling system was thereafter
projected.
22. EARTH AUGERs.
General Description and Method of Working.—Many types of earth
augers were tried, but that which gave most satisfaction was the
articulating jaw type of R.E. auger such as is used for boring post-
holes. These were used in two sizes, 6-in. and Io-in. diameter. The
auger consists of two halves, called “jaws,” the bottom ends of each
being pointed and turned towards each other to form part of a
helical Screw, with Cutting edges at the bottom. One jaw is fixed,
while the other is hinged at its upper end, and can be fastened in
position by a clip.
The Operation of boring consists in revolving the auger which
travels downwards in the soil or clay until the auger is full. It is
then withdrawn, and the movable jaw opened by moving the clip
fastener, and the contents emptied. Boring is continued, and rods
added as depth is gained.
With the first augers issued the rods were very weak at the joints.
These were replaced by rods consisting of 3-ft. and 4-ft. lengths of
#-in. and I-in. gas-pipe, the auger being provided with a male thread
to which these rods could be screwed. A T-shaped handle is provided
for turning.
Applications and Limitations.—The application of these earth
augers for geological test boring is limited. The maximum depth
that can be bored is I5 ft., although Occasionally by Special efforts
20 ft. may be obtained. An additional drawback is that, there being
no casing with this method, progress through running ground is
impossible. Not only so, but progress in really stiff clay is also very
difficult. At the same time, on the Bois Grenier to La Cordonnerie
front, it was found possible to bore horizontally with an 8-in. auger
to a distance of about 40 ft. (for the purpose of a camouflet) in
Ypresian clay.
In a few cases, however, before the introduction of the geological
test boring sets bores were put down to I2 ft. Or I5 ft. and gave a
certain amount of information as to the character of the ground.
The earth augers are, however, valuable in boring through fine and
medium grained gravel deposits which cannot be passed through by
57
the geological test borer. Where such gravel exists, the earth auger
should be used until the gravel is passed through, when boring 1S
continued by means of the geological test boring Set. º
In testing gravel deposits for quality of gravel, the earth auger is
Certainly the best instrument to use.
The earth augers have also been used in boring short holes for
placing explosive charges in torpedoes. This was found advisable
up to about 15 ft. ; beyond that distance or depth the '' Wombat ''
was a more efficient machine.
23. BORES FOR LISTENING PURPOSES.
In April, 1917, it was anticipated that the enemy might be mining
in the direction of the Spoil Bank, near the Ypres–Comines Canal.
It was not advisable at the time to withdraw tunnellers from else-
where in order to sink and tunnel at this locality. As a temporary
precautionary measure a number of bores were made near the front
line there to depths of 30 ft. The bores commenced in Paniselian
clay, and in some cases struck running sand before the Ypresian clay
was reached, in which latter case the bores were abandoned. In the
case of bores which remained dry until the Ypresian clay was
reached, after the boring rods were withdrawn, Solid steel rods, # in.
in diameter screwed and socketed, in Io-ft. lengths, were put down
the bore-hole so that the bottom of the rod, when connected together,
rested on the surface of the Ypresian clay, and the top projected
about a foot above the surface of the bore-hole. Listening was done
by connecting a geophone to the top of the rod in the usual way.
Similar bores were put down for the same purpose in the front line
at Shelley Lane, near St. Eloi, south of the Ypres–Comines Canal, to
a depth of 50 ft. ; and steel rods were then left in the bore, as above.
Only negative results were obtained, at either locality.
Probably better results would have been obtained from wooden
rods than from steel ones, as was demonstrated at the Second Army
Mine School at Proven. For the successful working of this device it
is, of course, necessary that the bores do not fill with water. Had
enemy mining been detected, it would then have been necessary to
sink and drive in order to get a base for estimating the direction of
the mining, as the relative intensity of Sound method, as deduced by
listening at each rod in succession along the line of rods, would give
results too approximate to be of practical value. This method
deserves further investigation by means of practical experiments
under peace conditions.
CHAPTER IV.
WINNING OF RAW MATERIALS.
24. ROAD METAL.
Early in the War a valuable report entitled “Note on Road Metal
in Belgium ” was made by Colonel P. J. van der Schueren, Chief
Engineer of the Belgian Ponts et Chaussées Dept., and by Captain
J. Millecam, engineer in the same department, both attached to the
Belgian Mission, at G.H.Q.
Important information on available road metal in Northern France
was supplied by Colonel Stoclet, D.S.O., Chief Engineer of Ponts et
Chaussées for the Dept. du Nord, and also by M. Thur, Chief Engineer
for Ponts et Chaussées in the Dept. des Travaux Publics, and the
engineers of the Chemin de Fer du Nord.
The chief stone worked for maintenance of the roads in the area
occupied by the British in Northern France was as follows:–
(i) Limestone from the great quarries of Marquise, between
Calais and Boulogne. These belong to an “inlier" of
carboniferous limestone surrounded by Jurassic rocks and
chalk.
(ii) Quartzites from Devonian “inliers,” surrounded by chalk,
like those of Dennebroeuca, Matringhem, Bergin, Rebreuve,
Marqueffles, etc.
(iii) Hard greenish porphyrite rocks from Brittany.
(iv) “Pierre de fosse,” a red carboniferous shale burnt to con-
sistency of brick through spontaneous combustion of
colliery dumps.
(v) Flint gravels (of quarternary age) mostly in Pas-de-Calais
country.
(vi) “Sarsens,” that is, occasional loose blocks of Tertiary
quartzite, found in Thanet sand areas.
&
The Marquise limestone areas and those of Devonian quartzite
and Brittany porphyrites were not specially examined by us, but
more attention had to be paid to the flint gravels and Sands.
In conjunction with a representative of the Director of Roads an
examination was made of the areas being exploited for gravel at Aire,
Arques and Engoudsent, chiefly in reference to their unworked
portions, and estimates of the probable resources still available.
Near Arques, in the remarkable gravel deposit which extends from
Aire past St. Martin to Payelville's gravel pits, near the Arques
58
59
railway station, a number of trial pits were sunk to depths of 20 to
25 ft. which revealed an immense development of these flint gravels
under an overburden of from ro to 15 ft. of sandy clay (limon).
A report was also made on the immense unworked gravel deposits
which extend from Wizerne to Wisques on the west side of the
Aa river. The available amount of gravel there was estimated at
about 3,000,000 tons.
From the point of view of supplying material (flint gravels and
sands) for the roads as well as for railway ballast, and for making
concrete, these supplies were practically inexhaustible for purposes
of this war.
A further report was made on possible sources of road metal near
Peronne and Vecquemont, and the use of the “ yellow chalk '' (a
magnesian or dolomitic chalk) of Eclusier as foundation material
(“blocage ") for the local roads was strongly recommended. This
yellow chalk is extraordinarily resistant to the action of frost.
It can be seen that in the local churches it has successfully with-
stood the action of frosts for hundreds of years. A recommendation
was made to test the yellow chalk for this purpose, at the Bois de
Célestine quarry on the north bank of the Somme, I2 miles west of
Peronne. Also at Etinghem, 2% miles east of the previous quarry,
and particularly at Eclusier, on the south side of the Somme, and
six miles west of Peronne.
As far as is known the experiment was never tried, but there is good
reason to believe that the yellow chalk, on account of its non-freezing
properties, would form a good foundation for local macadam roads.
At Vecguemont, near Querrieux, there were estimated to be 200,000
cubic yards of good sand, and IOO,000 cubic yards of good flint gravel.
Lists of chief quarries in the basins of the Somme, the Escaut and
on the Cambrai Plateau were supplied to the C.E.'s of Armies. In
the Oise area tests were made by means of boring with earth augers
of the flint gravels and coarse sand north of Noyon at Viry Noreuil
and Tergnier.
As the result of the enemy advance towards Amiens, the gravel
pits near that city could not be used as a source of gravel for concrete.
Sources of gravel were therefore sought further westwards behind the
Defence Zone. Gravel beds were thought, on geological grounds,
to exist in the valleys of the Authie and Grouches Rivers in the
vicinity of Doullens, but the amount of over-burden was not known
or the exact extent of the deposits. It was important to know the
thickness of Over-burden, as more than 8 ft. thereof made the working
of the deposit' inadvisable.
Accordingly, a series of test bores were made in the valleys of both
rivers. These were put down as far as the gravel bed, or, in the
absence of the latter, to the underlying chalk. The thickness of the
gravel bed itself was determined by working a chisel bit attached to
6O
the 3-in. boring rods through the deposit until the soft chalk under-
neath was encountered. In this way the extent of the deposit and
the amount of overburden were determined. It was found, as the
result of these tests, that only at one locality, namely at Thièvres,
Were the conditions anything approaching suitability, the average
amount of overburden being in the vicinity of 8 ft. It was ultimately
decided not to work these deposits.
The amount of gravel available in each was estimated at about
5OO,OOO tons. *
An interesting local Source of road metal, and particularly of
“ pavé,” is the “Sarsens" (“Saracen Stones") which are widely
Scattered Over the surface of the chalk in Northern France, wherever
the Thanet sands have recently been denuded away. These
" Sarsens" are hard, irregular-shaped concretions in the Thanet
Sands themselves. Being very hard, and therefore durable, they
are left as the only relics of the former Thanet sand in areas from
which it has been wholly denuded. In places, as at Camblain l’Abbé,
the “Sarsens '' can be seen in their original position in the Thanet
Sands at the local sandpits. The photograph (Fig. I7) illustrates One
of these “Sarsens '' at the “Pimple '' at the north end of Vimy Ridge.
In September, 1918, when the rapid advances of our Armies were
in progress, special geological reports were prepared showing the
exact location and approximate amounts of “pierre de fosse ’’
material available on First and Second Army fronts up to as far as
Mons. The amount was estimated at, at least, 50,000,000 tons.
At the Trith St. Leger flint gravel and sand beds it was estimated
that approximately 1,000,000 tons were available there.
A special map was prepared of the Carboniferous and Devonian
areas of the Avesnes—Bavai area, as well as a general map of Belgium,
based on the earlier report by Colonel P. J. van der Schueren and
Captain Millecam, showing the position of the chief quarries, like those
of Quenast, Lessines, Soignies, Maffle, Ecaussines, Tournai, etc., and
the principal sandpits. Sand was, of course, needed for packing
under pavé on the pavé roads so dominant in Central and Western
Belgium.
25. SAND AND AGGREGATE FOR CONCRETE.
This was obtained chiefly from the “ballastiéres" of the Chemin
de Fer du Nord at Aire and at Arques, and, latterly, chiefly from the
Engoudsent ballastiére.
From Engoudsent, as a centre, this material was widely distributed
along the front. A small portion was also obtained from the terrace
of River Somme gravel at Bourdon, near Flexicourt. The flint
shingle deposits of Inchville, Le Bourdel (at the mouth of the river
Somme) and the older inland shingle beds of the Conchil-le-Temple
and Rue were also examined. Both dune sand (from the Coastal
6I
dunes at Ghyvelde, between Dunkerque and Furnes, etc.) and Thanet
sand from near Arques, etc., were tried for mixing with Concrete, but
for practical purposes, chiefly on account of the extra labour in
mixing, they were not as satisfactory as the coarser flint sand
associated with the flint gravel in the ballastiéres. Some of the dune
sand was stated to be somewhat Saline. The Thanet Sand was used
for mixing with cement from the Orville pits, west of Authie, and at
Blaireville, four miles S.S.W. of Arras.
26. COAL MINES.
(A) Of Northern France.—In September, IQI8, with a view to
assisting the French Authorities in the Output of coal from such of
the Pas-de-Calais coal mines as were in working condition, an inquiry
was instituted at G.H.Q. in which the geologists were assisted by
Major H. M. Hudspeth, D.S.O., M.C., R.E., O.C. 171st Tunnelling
Company, R.E. (in civil life one of H.M. Inspectors of Collieries).
Lieut.-Colonel H. H. Yuill, D.S.O., M.C., R.E., also assisted in this
work, and afterwards took over the whole of it. The following
suggestions were made in the report —
(a) Closer co-operation as regards counter-battery work, and
anti-aircraft protection.
(b) Replacement of certain French miners then engaged on railway
work, so as to free them for colliery work.
(c) Limitation of the numbers of British troops billeted in areas
where accommodation for the miners was scarce.
(d) Evacuation of non-essential civilians from areas where
accommodation was needed for miners.
(e) Improvement of Canal and railway facilities.
(f) Assistance from England as regards plant and material.
Captain Laroque, of I72nd Tunnelling Company, R.E., was
appointed as Liaison Officer with the French Mission, working under
the Controller of Mines, First Army.
Special attention was given by the War Office to (f) and, in view of
the great shortage of oats in France which caused heavy mortality
among the colliery horses, to the provision of the necessary oats to
complete the ration for the pit-horses.
An interesting geological point developed in this enquiry was the
necessity for extreme caution in working the mines near Bethune
and Vendin, in view of the fact that geological faults led to local
upthrows of the Carboniferous limestone, which is Strongly water-
bearing. The carboniferous limestone is so highly Charged with
water under pressure that if, in following a coal seam, a drive Suddenly
strikes one of these faults which has brought up the carboniferous
limestone, the whole tunnel and even the whole mine may become
62
inundated. Part of the Vendin Concession was actually inundated
through this cause.
(B) Borinage Coal Mines, Belgium.–In view of assisting in the
re-starting of the Borinage coal mines, information as to the present
situation having been obtained from M. Lemaine (Secretary to the
Director in Brussels of the Belgian coal mines) as to the geological
and economic conditions of the field, meetings were held at Mons from
I8th November onwards between Lieut.-Colonel H. H. Yuill with
geologists from G.H.Q. and “L’Association Houillière du Couchant
de Mons' with M. Jaquet, Inspector-General of Belgian coal mines.
Consequent on the report giving the results of several conferences, it
was decided that the Controller of Mines, First Army, with Captain
Laroque as his Liaison Officer, should function in the same way for
the Belgian Coal mines as hitherto for the Lens coalfield, reporting
to the C.E., First Army. It was also agreed that assistance should
be given by the British in the repair of the Borinage colliery railways,
damaged by the enemy, and in the repair of railway bridges broken
by the enemy, between Mons and Jurbise.
A feature in this enquiry was the obvious great economic impor-
tance of the as yet undeveloped Campine coalfield situated in the
Limbourg and Antwerp provinces. These coal-measures are buried
under a great depth of water-bearing newer deposits (Quarternary and
Tertiary) which renders access to the coal-measures difficult.
On the eastern side of the field the thickness of this overburden is
about 1,500 ft., while it is as much as 890 metres (2,920 ft.) at Vlim-
meen in the Province of Antwerp and Helchteren in the Province of
Limbourg. Nevertheless, the field was obviously of great value for
future coal supplies, especially in the Antwerp area.
27. REPORT ON AGGREGATE USED IN GERMAN “PILL-BOXES ’’
ON THE WESTERN FRONT.
A Parliamentary Report was made in January, IQI8, in regard to
the “Transit Traffic across Holland of Materials Insceptible of
Employment as Military Supplies.”
In reference to the nature of the aggregate used in the German
concrete for military works, particularly at Messines, at localities
north of Gheluvelt between Becclaere and Zonnebeke, and between
Pilkem and Poelcappelle specimens were collected by Intelligence
Officers and collected by the Military Geologists and were taken to
England, where they were sliced for microscopic examination and
critically examined by a committee of experts, including the two
geologists on the E.-in-C.'s Staff. The general conclusion (p. 136 of
the Parliamentary Report) was that a good deal of the aggregate was
to be traced to a German source. “The Niedermendig ’’ rock and
the basalts of Linz and Erpel are represented by angular fragments,
63
such as result from quarrying. The fragments show no indication
of having been included as pebbles in a gravel or conglomerate.
The Triassic sandstone and silicified Oolite occur as pebbles.
It appears that of thirty-nine specimens submitted thirty-two are
of the same general type. In many of these pebbles occur which
prove that the material was not a Belgian gravel. On the other hand,
no pebbles occur which cannot be matched in the Rhine gravels,
and there is a notable absence of Belgian rocks. In the material
which appears to have been derived from quarries, some has been
recognized as coming from a German source.
CHAPTER V.
GEOLOGICAL ESTABLISHMENTS.
28. GEOLOGISTS IN THE GERMAN ARMY.
The Geological Establishment in the German Armies appears to
have been approximately as follows:– x
ARMY.
| | |
CORPS. LANDAUFNAHME. CORPS.
Field Survey Company. Research Geologists. Field Survey Company.
(Military):- (Civilian) (Military):—
Professional Geologist. Geological Group, Professional Geologist.
Assistant Geologist. Under Group Leader Assistant Geologist.
Draughtsman Draughtsmen Draughtsman
Clerk Clerks, etc. Clerk
Boring Party, Boring Party,
(?) 4 or 5 men. (?) 4 or 5 men.

It would appear that the Commanding Officer of the Field Survey
Company would issue general orders while the leader of the Geological
Group would arrange details. Normally applications for the services
of geologists were made to the Division, which then dealt with the
application.
The geologists under the command of the group leader were
divided into “Geologen Stellen " which were scattered over the Army
zone and placed as far forward as possible. It was stated that it
was not necessary to make requisition on the Army Commander or
Division Commander for having a geologist detailed for work within
the zone. The request could be made directly to the “Geologen
Stelle '’ or even to the individual geologist.
The officer in charge must have a constant personal touch with the
Army Staff, especially with the Chief Engineer, the Construction
Troops, Sanitation Official, etc. He must be acquainted with the
larger plans of the Army, contemplated change of troops, etc. He
acts as leader for the entire geological groups of the Army, for which
he is responsible, and he himself carries on investigations of the
larger problems presented.
The geologists of a “Geologen Stelle " are assigned to certain
sectors to certain problems. These officers are preferably located
near the Map Section, and their Headquarters are marked by signs
so that they can be easily found. It is very necessary that the
Geological Officers should be introduced to the different staffs with
which they may come in contact. The Geological Assistants,
N.C.O.'s and soldiers work either under the direction of a more
64
65
experienced geologist, or are put on special tasks, such as drilling and
boring.
The following is an account of the scope of the work of a Geological
Group, translated from a German document —
Geological Section of the Fifth Army.
CORPS HEADQUARTERS.
I–IO-I917.
I. The Geologists of the Fifth Army belong to Field Survey Companies
3 and I5, and form a geological section within these Companies.
Reserve Lieutenant X is in command of this section.
2. For the establishment of Geological Offices the Geologists are
distributed throughout the Army area according to the subjoined
Summary.
3. Application for the services of the Geologists will be made direct,
and to avoid unnecessary delay should give the object of the application
and the exact location of the area to be investigated.
The Geologists deal direct with the formations of their Army Sector.
. Applications for the service of Geologists must always be sent to
the Geological Offices of the Section which is nearest to the formation
which makes the application.
5. For Geological work in forward areas and on Lines of Communi-
cation, the formation that demands the work must provide labour and
transport and arrange for the rationing and billeting.
6. The duty of the Geologist is immediate assistance to the troops
in cases where the structure of the ground and its water-bearing qualities
are a consideration. Geological advice is of special importance with
reference to the following problems :---
I. Construction of Positions.
The assistance of a Geologist at the first reconnaissance of the country,
before the lines are finally fixed, has proved of special value. See
Regulations for Trench Warfare, for all Arms of the Service, Part Ib,
Cipher 2, and Part II, Directions for the laying-out of trenches,
tunnelled dug-outs, dug-outs, etc.
(a) In cases where several points are of the same tactical value by
choosing Such as require the minimum expenditure of labour, time and
material, and are not likely to involve land slides or inflow of water.
(b) The prediction, in the case of lines already dug, as to what diffi-
culties are likely to OCCur arising out of the hardness of the strata, and
their water-bearing qualities.
(c) Information as to tracts in which dry dug-outs are definitely im-
possible, or whether there is any prospect of draining them by natural
means, as by drainage Sumps.
(d) Testing the possibility of putting in dry tunnelled dug-outs under
the water-bearing Strata.
(e) Advice on Subways and galleries. Information as to which strata
are the easiest to work, whether there is risk of landslide or inflow of water,
the possibility of tunnelling under water channels.
(f) A preliminary investigation with a view to the use of boring
machines in mine Warfare. Selection of favourable and exclusion of
unfavourable strata, ,--
E
66
(g) Information as to the best dug-outs for listening posts and so forth.
(h) Opinion as to the stability of existing “subterraneans " (caves
and quarries).
(i) Inundations and drainage of areas.
II. Water Supply.
(a) Improvement of existing wells and selection of sites for new ones.
(b) Making good defects in existing springs, and the opening up of
116W OneS.
(c) Information as to places specially suited for driving wells. (Wells
made by percussion, Abyssinian wells.)
(d) The development of deep-seated water basins by deep bores.
(e) The ensuring of water supply for the defensive battle.
(f) Advice on construction of water conduits, the water supply of
towns and camps, and of industrial and commercial establishments.
III. Winning of Raw Material.
For immediate use in the field. The providing of gravel, sand, loam,
clay, building Stone, material for cement and plaster, road metal, railway
ballast and peat, as near as possible to the places where they are to be
used. The marking out of stone quarries, estimate of quantities,
information about the stratification and best way of working.
(b) Providing of raw material for supplying the needs of the Army.
One of the first considerations is the supply, for example, of pyrites,
phosphates, copper and, in the Balkan Peninsula, of coal also, for the
Directors of Military Railways.
(c) Records of the existence in more distant industrial fields of
material available for meeting the requirements of munition and Ordnance
factories (new occurrences), abandoned mines, and their ancient mine
and slag dumps.
Of chief importance are ores, rock-oil, coal, asphalt and other materials
useful in the economies of war.
IV. Hygienic and Technical Problems.
(a) Advice on the location of sumps for drainage, Cesspits, drainage
in general, disinfecting and delousing establishments and cemeteries
from the point of view of risk of contamination of sources of water
Supply. .
(b) The defining of drainage areas with a view to the protection of
wells and springs, having due regard to the nature of the ground.
(c) Electrical problems so far as controlled by the condition of the
ground with reference to earthing, erecting masts and burying cables.
(d) Advice on the locating of roads, field railways, light railways,
cable tram-lines, with a view to avoiding, when making, Cutting or
embankments. º
(e) Appreciation of suitable sites for dams.
V. Other Military Problems.
(a) Careful observation of the structure of the Substrata (nature,
solidity, water-content) for standing camps.
(b) Choice of dry substrata for munition dumps.
(c) Choice of suitable natural solid surfaces for heavy guns.
(d) Choice of spots naturally fitted for aerodromes.
67
The function of the Geologist is only advisory. It is not his province
to see to the technical development of propositions by elaborating
them from plans or actual superintendence of the work.
29. GEOLOGISTS IN THE AMERICAN ARMY.
Lieut.-Colonel Alfred H. Brooks, Director for many years of the
Geological Survey of Alaska, was appointed Geologist to the
American Armies in 1917. He worked under the Chief Engineer at
American G.H.Q. A little later an assistant Geologist was appointed.
Geological maps were produced of special areas of the American
line on the Western Front, with a view to giving reliable data,
particularly as to the water-bearing properties of the Strata —
(a) at the surface, or
(b) at a depth.
The various water-bearing horizons and their depths below the
Surface were shown in sections at the foot of the map. These maps
were on a scale of I/50,000. They showed contour lines at intervals
of IO metres. The cartographic details were mostly from the “Plan
Directeur,” and the geological details chiefly from the “Service
Géologique de la France.”
The geological information was partly supplied on the geological
maps themselves and partly given in the form of clearly written
engineer field notes such as those on “Underground Water and its
Relation to Field Works.”
After consultations between the British Geologists and Lieut.-
Colonel Alfred H. Brooks it was decided by the American G.H.Q. to
raise the number of Geologists with the American Forces to a total
of I7, and most of these were actually appointed before the signing
of the Armistice. It was tentatively suggested that in the matter of
water supply a closer liaison between the Geologists and the Water
Supply Officers would have been desirable, but otherwise the
organization worked satisfactorily.
30. SUGGESTED GEOLOGICAL ESTABLISHMENT FOR THE BRITISH
ARMY.
The following proposal was put forward in September, IQ18, for
a Geological Section, R.E., under the Engineer-in-Chief on a similar
status to “Camouflage,” etc. —
At G.H.Q.
Commandant (Geologist) - - - ... Major or Lieut.-Col.
Assistant Commandant (Geologist) ... Captain
Clerk-Typist tº e - * e e tº e e . . . I
Draughtsmen ... ... 3
(With car.)
68
At H.Q. of an Army.
Geologist ... tº e e © e º tº tº e ... Captain or Lieut.
Clerk-Typist gº º º * * * tº $ tº . . . I
Draughtsman ... I
With box car to transport light boring plant and keep
Geologist in touch with work in Army Area.
Total Personnel for G.H.Q. and 5 Armies.
Geologists e tº e is º e * tº gº ... 7
Draughtsmen ... gº tº tº tº s e ... 8
Clerks-Typists ... tº e & 4 e e ... 6
Drivers (M.T.) ... & º º & e e ... 6
Total ... tº $ tº $ tº e ... 27
The Suitability of Such an establishment was generally recognized,
though the proposal was put forward at too late a date to materialize.
But should the British Empire in the future become involved in
another war there can be no question but that the existence of an
adequate Geological Staff from the commencement would be the
means of much saving of expense, labour, and life.
While it is not suggested that Geologists should necessarily belong
to the Regular Army in peace time, it is certainly desirable that such
touch should be kept with H.M. Geological Survey, and such
machinery exist, as will ensure the presence of a geological staff with
any future British Army from the outbreak of hostilities.
INDEX.
AA R, 59
Acme plant, 28, 29, 50, 55, Pl. VII
Air-lift, I 6
Aire R, 58
Alençon, I5
American E. F., 9
Geologists, 67
Ambleteuse, I4
Amiens, 59
Arbre, 42
Armentières, 36, 58
Arques, 58
Arras, 28, 37, 44, Fig. I 5
Artesian water, 22
Ashford strainer, I 6, 17
Australian Mining Corps vii, viii, I5,
32, 37, 39, 53
Tunnelling Co., 2nd, 32, 33, 39
3rd, 39, 55
Authie R., 20, 59, 6 I
Avre syncline, 2O
BAPAUME, 20
Barrois, Prof., vii, 3 I
‘‘ Bassin de Paris, ’’ 20
Battle Wood, 3 I
Beauguesne, 2O
Beaurains, 2I
Beaurainville, 46
Beauval, 20
Beeby-Thompson strainer, I8
Belgium, vii, 9
Bergin, 58
Eethencourt, I 8
Bethune, I2
Blaireville, 6I
Blaton Canal, 45
Hoesinghe, 32
Bois Grenicr, 38, 56
Bores, 9, 12, 18
Borinage mines, 62
Boring plant, 47
method, 48, 5 I
rate of, 50, 52, 54
Boulogne, I4
Bourdon, 60
Boyle's Farm, 30
Brooks, Lt.-Col. A. H., I5, 67
Broom & Wade Simplex, I 7
Bruges, 35, 37
Bunny Hutch shaft, 22
Bunter sandstone, I4
CALONNE, 25, 28
Camblain l’Abbé, 60
Cambrai, 38, 59
Campine coalfield, 62
Canadian Forestry Corps, 9, 15
Canal du Centre, 45
Canal du Nord, 2 I
Candas, 2O
Card-index of bores, I8
Carte géologique de la Belgique, 35
Caterpillar, 3.I
Cayeux, M., 20
Chalk marls, I3
water table, 23
Charleroi-Brussels Canal, 45
Chassery Crater, 29, 30, Fig. I 7
Chaulnes, 20
Chief Engineer, H.E.F., vii
Clapham Junction, 3 I, Fig. I6
Clay with flints, 45
Coal, 6 I
Company, R.E., I81st, 38
I84th, 32
25 Ist, 55
255th, 38
256th, 32
257th, 32
Conchil-le-Temple, 60
Concrete aggregate, 60
Copse, The, 25, 27, 28
Corallian, I4
Courban, I4, I 5
Coventry shaft, 22, Fig. 2
Croydon Waterworks, 25
Crushing of dug-out timbers, 40
Cuinchy, 45, 55
Cunewale, I 7
Cyprima Morrisii, 23
=
D. F. W., vii
Dams, 46
David, Sir T. W. E., vii
Dendre, R., 45
Dennebroeucq, 58
Director of Geological Survey, vii, 35.
4O, 45
Dixmude, 35, 36, 38
Dollfus M., 20
Double Crassier, 25, 27
Doullens, 59
Douve, Petite, 31
Dug-outs, 37
Dumbarton Wood, 31
Dane, Grande, 32
Earth augers, 56
ECaussines, 60
Ecclos, 36
Eclusier, 59
Engoudsent, 58, 60
Escaut R., 21, 45, 59
Establishment (suggested), 67
Explosion trench, 29
7o
FESTUBERT, 38
Fidoe, Capt. J. W., 23
Fienvillers, 2 I
Flanders, I 3, 15
Fleurbaix, 39
Flint shingle, 60
Flot de Wingles, 24, 27
Folie, La., 29
Foundations, 45
Fressenneville, I 3
GAPENNES, 43, Fig. I 5
Gauze strainer, I 6
Geological Survey and Museum vii, 68
Geological Section, R.E., 67
Geophone, 57
German Geologists, 64
Ghent, II, 35
Ghyvelde, 61
Givenchy-lez-La Bassée 22, 23, 28
Gosselet, M. 2 I, 28
Gouy Servins, I 3
Gravel, 57, 58
Great Oolite, I 5
Green sands, I 6
Grouches R., 59
Gurlu Wood, I 3
HAIRPIN, THE, 28
Hill 60, 22, 30, 3 I, 32, Figs. 9, I2
Hill 7o, 25, 27, 28, 55
Hills, Lieut. L., viii, 45
Hirondelle R., 2 I
Bois d’, 37
Hohenzollern, 27, 28
Hollebeke, 37
Hordern, Sir S., vii
Horse-hair strainer, I6
Horizontal bores, 29, 52, 53, 54, 56
Hontkerque, I6
Hudspeth, Major, 61
Hulluch, 27, 28
Hunter, Capt., S., 33, 53
Hunter drill, 56
I.R.E.M. at G.H.Q., 9
Ignon R., 2I
Imbeaux, Dr., vii, I5
Inchville, 60
Independent Air Force, 9, I4
India-Rubber House, 34
Infra-Lias, I 4
Ingersol-Rand, I 6
Inspector of Mines, vii, 32
Intelligence reports, I2
Jogu ET, M., 62
Jay's Post, 39
Jurassic rock, I 4
KEMMEL SANDs, 22, 31, Fig. 9, Pl. V
Keystone drill, 55
Kimeridgian, I 4
King, Capt. W. B. R., vii
Rruisstraat. 31
LA BAsséE CANAL. 24, 27, 28, Fig. 2
La Cordonnerie, 38, 56
La Panne, 32
Landenian Sands, I4, 15, 16, 17
Laroque, Capt., 61, 62
Lassigny, 38
Le Bourdel, 60
Lemaine, M., 62
Lemoine, M., 20
Lens, I2
Lessines, 60
Liane, R., I4
Lias, I4
Lignites, 38
Lille, 3 I
Limon, 59
JListening bores, 57
LOOS, 25, 27, 28
Louvil clay, I 5, 16, 28
Lys R., 36, 37, 39
MAEDELSTEDE FARM, 3 I
Maffle, 60
Malatray M., 27, 28
Maps, 9, I2
Marine sand, 34
Marl and flint, IQ
Marqueffles, 28, 58, Fig. 6
Marquise, 58
Matringhem, 58
Messines, 30, 3I, 37, 42
Meuse, R., 45
Millecam, Capt. J., 58, 60
Mining, 22 et Seq., 28, Figs. 8, Io
Monchy-au-Bois, 2 I
Monchy-le-Preux, 37
Mons-Condé Canal, 45
Montreuil, 44
NAMUR, Io, Flg. I 8
Nancy, I4
Neuve Chapelle, 38, 39
Neuve Eglise, I 6
Neuville St. Vaast, 29
Nieuport, 32, 34, 35, 38, 56
North Shaft, 22
Noyon, 37, 38, 59
Nurlu, 2O
OISE. R., 2 I, 59
Ontario Farm, 30, 32, Flg. II
Oxfordian, I4
PANISELIAN CLAY, 22, 3 I,
57, Fig. 9
Passchendaele, 22, 3 I, 35, 37
Pavé, 60
Peckham, 3 I
Peronne, 38, 59
IPheasant trench, 42
Pierre de Fosse, 58, 60
Pill-boxes (German), 62
Pimple, The, 28, 60, Figs. 6, 17
T'lant for water-bearing Sand, 33, Fig. I 3
Ploegsteert, 22, 30, 3 I, 36, 38
Polder clay, 35
plain, 36, Pl. I
Polygon, 3 I
Ponts et chaussées, Engineer, 9
Pozières, I 3
Pruvost, M.P., vii
Putney Bridge, 35
32, 42, 45,
71
QUARANTINE, 2
Quarry water, 24
Quenast, 60
RAINCHEVAL, 2O
Red Dragon Crater, 22, 23, Fig. I
Rebreuve, 58
Renier, Prof. A., vii
Rhaetic sandstone, 14
Riaumont Wood, 37
Road metal, 58
Roclincourt, I 3
Roulers, 36
Rubempre, 45
Rue, 60
SABLES DE PERCHE, I 5
St. Eloi, 30, 3 I, 32
St. Quentin, 37
Sambre R., 45
Sand, 60
Sand pump, 51, Pl. VII
Sarsens, 58, 60, Fig. I 7
Saulty, I 3, 2I
Scarpe R., 9
Senonian (upper chalk), 12
Sensée R., 2 I
marshes, 24
Shell-holes, 36
Shelley Lane, 57
Sherpenberg, 43, Fig. I4
Shrewsbury Forest, 31
Skeleton bit, 50
Soignies, 60
Somme R., 9, 59, 60
Souchez R., 25
Soupirails, 44
Souterrains, 43, Fig. I 5
Southampton vii, 9, 38
Spanbroekmolen, 31
Spoil Bank, 57
Staden Ridge, 37, 38
Star drill, 55
Steiner, Prof., vii
Stoclet, Colonel, 58
Stone, types of, 58
Synclines, 20
TANK MAPS, 45
Test boring set, 48, Pl. VI
Thanet sands, I4, I5, 16, 17, 38, 60, 61
Thielt, 37
Thièvres, 60
Thur M., 58
Tortille R., 2I
Tournai, 60
Triangle, The, 25, 27, 28
Trias, I4
Trith St. Leger, 60
Tubbing in segments, 39
Tube well pumps, I 6, 18
Tun, I2
Tunnelling Co., I 71st, 30
I 76th, 28
Turonian chalk, I2
VAN DER SCHUEREN, CoLoRNEL, 58, 60
Vecquemont, 59
Vendin, 61
Verbrandenmolen, 3 I
Verse R., 2 I
Vimy Ridge, I 3, 28, 29, 55, 56, Pl. II,
Figs. 6, I 9
W. S. OFFICERs, 9, 12, 13
Water-jet boring, 33, Fig. 13
Water supply, 9, Fig. 18
table, II, I 3, Figs. 3, 4, 5
Wimereux, 14
Wisdues, 59
Wizerne, 59
Wombat machine, 28, 29, 30, 44, 52, 53,
57, Fig. 7
Wynze shaft, 30
Wytschaete, 22, 30, 31, 37, Pl. IV, V
YELLOW CHALK, 59
Ypresian clay, I4, I 5, 30, 31, 32, 33,
35, 38, 40, 56, 57
Sands, 37, 55
Yser R., 33, Fig. I 3
Yuille, Lt.-Col., 61, 62
ZEEBRU GGE, 35
Zonnebeke, 3 I
.. º - º
..". º --- * - 7 ſº -
* * * *sº §§ º º
* * * * , º, ... "…
... “Wombat" Blow. Near Chassery Crater, Vimy Ridge.













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Fig. 11.—Crater at Ontario Farm.

GEOLOGICAL SECTION ALond FRONT LINE TRENCHES
Vertical Scale
From NIEUPORT To THE SONMME.
PLATE I
Verhcal 5cale
Mehres. Metres.
/3o- wºo
120.
wºo
Iſo-
I/O
/od.
|- ſoo
90-
- 30
8o-
F O L D F R P L A | N ////62 |- 80
Zo- **** - Zo
; : Cana/
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5.o- - Road from W A’ailway ! :
Lighthouse NE/Poºr PERwyse Oosſkerke Oupscapell= YSER CANAL MART-EVAART STEENSTR4Ar Allcataſ ſo YPºE’s 1F17/r Road ºr \/
YSER Duwkº Rauf | | | | I : : Yoºfs fo, Zowave arº
3a. i | - ~~~~
| CANAL | cºal I | I | | ! * - L. ---..." . . . . ;------...-----ºº-ºº:
2a. - I I | I
| | | | | I | | |
ſo- - —sº | | - | | I |- ſo
o- º ---------------------> ------------------FFFFE-----------------------------------------. § -------'º - tº-- ~~- "Tº Lº - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -- 0
-- - " - ". . . , - - - - - - - --- - - - - * * *... " - - * - - - - - - - -" - *
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . - Mo
* . . . . . . . . . . . . . . . . . . . . . ~-TT - ad
|->o
*o- H-wo
<º- - 50
6a -Go
Za- - 22
82. -8d
sol. ----------------------------------------- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - ------------------------------------------------------------ — — — — — — — — — — . . . . . . . . . . . L90
QUAR75/7NA ſºver alluvials and sandy clays Ajandrian Sands. Greenish brown sandy clays Yoresian Sands. Ypresian clay, (Blue clay Thaneh Sands, Very fine UPPER Chalk wih or without MIDDLE Moshy Chalk Marls underlying
(ſimon and Joess) of Alaheavy Eocene: and sands. Ranselian. ſocFNE Boceava: º London Clay). ºfocºmº glanconific sands. CRETAcrous flinks CRETAcEous tun' (hard chalk).
and Polder clays, sands,
and sand dungs. -
-
º
Werf.ca/ .5cale
Verhcal Scale.
Mehres
Metres.
/5o- /so
/2c - - -/20
//o- |-ſ/o
ſoo
Go
&n Road from |-go
- Perºr Bois Wozzº&fºr ſo Wrzschafrº - |- 80
Zo- : a ar a’ a Road fron H22
: . oacy rºrorº oved aro/77 AAPMENT/FAPES
60- Aroana atron . War, weadhºm MEss/aves fo fo Fººl/Mah/E/y Aroad arom |- so
sº. Wºrschaffe to to Messives Aroads 7554-7 ST: Yvow Aroad arown Road arown Gºvercºr, ſex CAM5Rºw ſo
Wreas Tºday : | : ! /*ERME de ſo Aroad from Rue du frne orande Boſs Cºfnºfr? Powr Loay no La Quayoveſ /g BASSEE ſa BasséE Rajſway |-so
+a. : - - stream. . Mrſ/ /e 7ouque 7" : Mouawoere ſ'Aſprºve T7a: AAPMEWT/EAPE's Boys flamenyrie o Rap/Mahéaſ ſa BowTille Rue Laues ºf rew favoussaer Weuve Cavapezº-e. Tourvºaia Aftwa ! /a B - : ! Hºo
- ; : ſº - l - " – . : - | - . - - Assée -
*+--> º N. : - : Aº. * | | **** *o A/LLE | ***ay ! : º : : . : i ſº "cA. . : Hºo
- - : I - : - a t ſº - - : :
2d º º ; : i ºf ſº - C–T-T-. - —&— —&— _ —ſº- -- ſ- - - 20
|- ſo
--------------------------- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - --- --->
Aºza/7/wo C2/2/.../24. 276/
Horizon/a/ Scale
ſood ~ road -ooo 3aoo -zood <ºdoo --~~~ 2-coo sºo-
Li Lil Li Li Ll
ºdoo Æood azoo Mºdº ºzoo.o afood
1


































EOLOGICAL SEC
Verhea/ Jeale.
Mehres.
sº
fºol
tºo
ſeq.
no.
Zoos
Aroad from
wood from ZEW’s ſo Berracaº
tº- Loos /o
ſa Bassée
30+
Quarries I
–s
aro.º.º. ºrorº º
Zººs ºo /e &assés
2–
TION ALond FRONT LINE TRENCHES FROM NIEUPORT to THE
WIMY RIDGE
Wafaywaza S. 7
VAAs7"
Aroad arown afoºdſ arom
X? Arºas no foºd arom ºoadſ arom Æoad’ rºom ARøas ho no Bower
45^'s Aºozitawcowr $7: Nicolai to Baltiew Aaaas * Cambºdy. BAPAwarf. 86.4/24/A's 57. ***.
-- º - - i ro Tºé. Lºs Failway | |
- - "…a
- - C’ - -
C/Tº Awares / ) - 8. Amor
Calowave -
Railway º ar. Jºcarpº
-
cº |_º * = 1 & 4–
SONMNME
Road ºwn Agºs
Æaſſº
PLATE II
Vertical Scale.
Mehres.
-
AºAwsary
Mºoed ºwn
Mºaa..jaz7 º
a 65/14code º:
|
Mºosa arom
814ſºfWilf a 8444/owz
| Shream.
| I
| N _-
&-
* -
921 - . . . . . .2-1. . . . . . . . .______________________ _ _ _ _ _ _ _ _
Aºver aſkwa/s and sandy clays focºm Louvil Clay with hard
*T (ſimon and loess) of Ala/eaux. OCENE. T calcareous bands ("ſuffeaucº
Verhical 5cale. Aroad arom A/A/wwºscamps
Mehres. * *owcºr-ºw ºozo ºrom Cowatercour*T
17o *:::. ** *** rawesoames, ". de ſº
o/ - Yº LLE.
160 zº-> -S Bacºvo
|-o ºfº -
A/w/º (2/24. /(24.2%
-
- N to Bearwowr- -
names. 24–
//AMEL Woodſ LA
/Awcare
Rºyer
Horgon/a/ Scale.
ax- o -7 --> - --~~~ sº 6aº zoo.o 8000 º -o -7 A-20 --> --wo wººd -ºoºº- º wºodw
LA 1 1 - 1 - . . . 1 1 I l 1. 1 l 1 1. l I I 1 1 1 1. _l 1 _l Maº's
ro ºraycary’ | Road from Mauſºpas
to Ae Powąsr
-Ali
roadſ arov
Mauwepas
150
[.
|-wºo.
--~~
|-wo
|-loo
|-30
- so
|-72
-60
---------------~~~~~~~~-L-----> ---------L----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- -------------------------------------- --------------------- - - - - - - - - - - -32
UPPER chalk whº or without MIDDLE Mostly Chalk Mark underlying Low ER Lower Chalk grey and while Tº Shales, Sands ones Dºwowian ovarðiſes and Moshy dark
CRETA cºous. flints. CRETAccous. [T] "tum" (hard chalk). cºus marls with glanconific greensands *assicſ CARBONIFEROu,5. º and Coal Seams. - [T] red shakes SILuºian. Z Calcareous Shales.
and gravels ("ºurfia) & base.
Wern le.
Æoad arown Bazaayrray- woad own Aroad ºran ſcal º::
- Azazºr to Bapaume Ae-aer/7- Lowdºwevºu. Lowaczew ho Livo
I
Héavreawe Road from /o *c. ºfa's *ºf |- IGo
Aroad arorra Mauly- Manºer to Seafºe: Mouyue" fºrm I - | _* Cºlleafow?" Roadſ arº
- º Héevrºne to SE&af I Road from Auchowvillers 77+/Eawaz. º -> ser- º ºo.3df frcº A444/weads -->
- T º Mawaetaas to Caºrates Lºo
Lºo
|-rºo
--->
-koo















































/wdex :
WER7/CAI
Scale.
Me/res.
/30 -
/20 -
//O –
/OO -
SO –
80 -
70 -
60 -
50-
40 –
30 —
2O -
/O -
A'oad from
//AM ro
I
-
- DALLow
| Cana/.
Pºwr/wg Co RAE/W0 B 2757
ST QUEwſ/w. SOMME WALLEY
GFFEgovº 7-
i Aº SoMME |
Arecen/* A//a/w/urn.
GA’0/G/ES
GEological SECTION fºod Near St QUENTIN To
and Loarn.
Aroad from
ST: Queav7//v
fo ESS ſaw Y ſe GAAwd
!
!
|
I
Older Aſſuvium.
*...*. a Sable de Beauchamp.
§ 2. Graveſ 7erraces. (w//h pebbles)
UAvila FA's
| Junchion of Road Boys de
| from BEA’away cam BAY
|
| fo Cf A’ſ 2: Y. | Afoazy Aror”
| | & ////v4.cova’7
- - to MAY
t
SS
METREs, looo O
Argiſe de Sain/ Fºl Caſcºire Cross/er º; Sana's wiſh 73/es
CoA,ain. fossiliferous robb/y :. . . . de chaſs. (Aara
//rnes/on.e. sandy concrerºons)
REM/aavy:
Cross Aroad's
LY Fow/A/we |
t I
|
:
I
I
|
CROZA 7"
Cana/
Lignife diggings
i
SEA LºvEZ.
- - - - - - -------------------------------------------------------------------------------------- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - --------------------- - - - - - -
DATUM.
/ OOO 2.OOO 3, OOO 4.OOO S.OOO
— //OR/Zory744. JoA. E.
-
THE FORÉT de ST GOBAIN
* “I Jables ale Brºchewy
C/ag band (< Pamiseſian) F ". .
*... near ſo 77%ame/ Jºnal
- Argile a/asſºque and
Sables ale Curse, wiſh
//gniſes, near /o
I
| C.ross Roads
|
ſ
º way
Té/es de cha/s. - resian clay horizon. (Fine
Aj3on. greensands)
AM/a/yy-Aºot/Y
|
I
TEA’a/V/ER I
oise Valley
Basse Foré 7 de
S7. GoBA//v
l
Clay near ho horizon
of Zouviſ C/ay.
(hard sandy shale)
Railway
I
I
Canal I
PLATE III
Cha/A few f/in/s.
BAA/S/s
Æailway.
ſoooo /ME 7/?aſs. ”
Vea'7/cA/.
Scaze.
AMeare's
–2OO
- Z90
– MBO
L/70
L /60
L/50






















i
Blarney Rd.º.º.
exº
i
|: IO,OOO.
Laterie,
ºrkº
-
Godeºnne Fºº
-45
N º -
ſº Vierstraat
º º
Tºwer Mill
-- - - ºf ſº
-- 7 - -ºº º ** > -- - I - - --- Rº º
% Berghe Fº - /
-
--
- -
- -
-
---
--- -
- - -
- º
-
-
- (, Spanbrºekmolen
in ge Spanbroek
sº cabº
*-
*-s
i
{
*
*/ A 2.
à
| stáenyzer Cabº
º,
G.S., G.S. 3052,
BELGIAN BORES
-
C. —
*
BRITISH BORES
*
- * * *
-
— REFERENCE:-
Good. sº
Doubtful, Alluvial not ºpletely 3: = Alluvial Sand.
III penetrated at depth given Qc. = Alluvial Clay.
Scale 1: 10,000
kilometre
**
GENERAL CLASSIFICATION OF GROUND
-
- T. Special areas marked Good 2 Fair? Both are promising for dugouts.
+-- *
- ACCORDING TO
Q Good.
O Fair. ITS SUITABILITY FOR DUG-OUTS, &c.
Bad.
- - - - --
Cr-- * special areas proved by British Bores to be Good, Fair, or Bad.
The numbers on the colour blocks indicate the geologieal
sequence in descending order, eight being the oldest and
lowest.
SPRINGs. wherever these are shown the ground may be
expected to be wet for some distance along the same contour as that
of the spring.
N.B.-in well drained sites the strata classified as bad may occasionally
be found to be good for dug-outs.
WYTSCHAETE
ºff wide
ºf geºl
rkte yºbº.
º
} <
Şss.
º
**-
&
W tº Nº.
Yº º | \ ºf
ºf . Goudezeune
º | -- -
-
-
- *
º
º
-----
ºpenºi.
.*
EDITION 7.
* Lincoln Los ge
º
---
-
-
-T
- *...*
- -
Fº
-
------
º, -
-------
- ****.
- - - -
- ...
-
º
º
-
º
i.
-
º
PLATF. IV.
*Feathe; i.
_º
-
Part
º
y
née Fº
1 Mile
Yards 10C
__
GOOD
(Relatively)
GOOD (Mostly)
MOSTLY FAIR
TO GOOD
(Relatively)
The “Wytschaete Sands,” a continuance of the
Sand Beds at the Summit of WYTSCHAETE. These
form thin cappings on the Passchendaele Ridge,
especially to North of Passchendaele. The ground
here is probably dry to depths of 15 to 20 feet.
“Ypres Clay." This is covered by a greater or
less thickness of Alluvials, the thickness of which
should be tested by trial bores. Recent bores have
proved that at certain places the surface of the
Blue Clay is too sandy and watery to be of use for
dugouts. The Blue Clay should therefore be well
tested before shafts are sunk. At good spots free
from sand, it should be possible to get 30 feet, or
more, of cover in this clay.
Brownish Grey to Greenish Grey Sands and
Sandy Clays with occasional small patches of Clay.
These are probably dry to depths of 8 to 20 feet.
| 700 Yards
1 kilometre
FAIR TO
DOUBTFUL
5
FAIR TO
DOUBTFUL
BAD (Mostly)
Chiefly Greenish sandy beds, fair where drainage
is good. . In the best spots these may be dry to a
depth of from 15 to 30 feet.
Sandy Clays, mostly Clay. These are very vari-
able. In the good patches more than 20 feet of
cover may occasionally be obtained. In other spots
they are more or less water-logged.
“Ypres Sands," mostly water-logged; only fit for
dugouts where natural drainage is very good, when
these may be fairly dry to a depth of about 10 to 20
feet, except after heavy rain, when they will be
temporarily saturated to the surface.
BAD
BAD TO
POSSIBLE
BAD (Pol.)
BAD
-
-
-
Ordnanee Survey, May, 1918.
* Kemmel Sands", mostly water-logged except
where the drainage is good, where they may be
dry to depths of 15 to 25 feet below the surface.
Recent Alluvials of Valley bottoms, mostly water-
logged.
Wet ground formed chiefly of recent and older
Alluvials in places covering the Blue Clay (“Ypres
Clay") areas, as well as irregular areas of 2–6,
Dug-outs are possible, in places, in these areas.
Polder Clay and Sand.
few feet below the surface.
Water everywhere at a
These areas mostly impossible for dug-outs.
.
\
\
Sº
S. 3.
* *
s -
S-
º
*
º -
On squared maps all
bearings should be given
with reference to the vertical
grid lines, which are parallel
to the East and West edges of
the sheet. Bearings should
always be reckoned clock-
wise from Cº to 360°
Grid bearings are less
than compass bearings, the
difference being called the
deviation of the compass.
To find out what this
deviation is, take a compass
bearing to a distant point,
and measure on the map
the grid bearing to that
point. The difference between
the two bearings is the de-
viation of that compass from
Grid North. To obtain the
grid bearing of any point this
deviation must be subtracted
from the compass bearing
(adding 360° to the latter
if necessary).
On this sheet the mean de-
viation of a normal compass
is 12° 23' ; but to obtain
accurate results the exact
deviation of each compass
should be tested as described
above, and this test should
be repeated in each locality.
To fix the position of a
point within a square the
decimal system is used, as
described on the 1: 20,000
and 1:40,000 maps, whereby
the square sides are con-
sidered to be divided into
ten parts. (As an aid to
measurement, two sides of
each 500 yard square on
these maps are divided into
ten by small ticks). This
system indicates the position
of a point approximately. By
a simple extension it may be
used to fix a point more
accurately, by considering the
sides as divided into loo
parts, and using four figures
The following rules must
be observed:-
(1) Use the figure 0, but
never 10 or 100.
(2) Use either two or four
figures, never one or
three.
(3) When using two figures,
describe a point by the
nearest intersection,
Examples:
Two figures:-
Point A is 08.
* B ºn 30.
a 0 , 54.
Four figures:–
Point C is 6.242.
D AGRAM
- |-
5 § --|--|--|--
7. -- –
8 -
5. i- --- --
| | | | | | |
--|--|--
º -- | | | ---
2 | | | | -- - -
--- -
B |
2 - + 5. 5 7 º' 9
INDEX To ADJOINING SPEETs
28 Nºw. 28 N.E.
3. 4. 3.
%
%2% º
235 wº 28s. E.
3. - -
J 422.40 m. n



















DIAGRAMMATIC SECTION
PLATE
WYTSCHAETE AREA
Metres Feet WYTSCHAETE
82-------- 269 - Vertical Scale 25 feet t inch
sº 80 m. eft| Gaſ SC3/6 86L to One II) C
2 N The altitudes given correspond with those on
75 245 75 m the official contoured maps 1:10,000 scale.
-------- N Horizontal Scale | |0,000
Scale 1: 10,000 º # # Mile
-- 70 m), Trrrrrr -] i i T I t i I i I I T i T T H
Kilometre I Yards IOO O 500 O iOOO 1500 17OO Yards
- Ł I I l l I I I | | | Kilometre
3 \
- Sº"
200 —
s:00 I)).
º
4. `s
N
tº 50 m.
48________ 157 T-----—
—?”"
L_-
40 m.
6
Joyce Farm
27--------- 88
24 m.
8
50
45
40
35
30
25
G00D GOOD MOSTLY FAIR FAIR T0
RELA TiVELY M0STLY TO GOOD DOUBTFUL BAD BAD
Wytschaete Ypres Clay, Sandy Cſay Lenticular - Kemmel Water-logged
2 Sands 8 with occasional 3 & Sand 6 Clays 4. Sands I Alluvials
wet sand pockets & Sands mostly wet
near fts surface.
Ordnance Survey, March 1918.


DETALS FOR GEOLOGICAL TEST BORING SETs. PLATE VI
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woa/ws *TS: Clu, 4. 22% // borng.
* ; \, = 2 * ~ * - - - 7. W y -
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IMPROVEMENTS TO ACME BORING MACHINE FOR BORING IN CHALK. Plate VII.
O / 2 J <! 5 6
/ ches L. L-L-L- † | | |
A" •
+4−/−.
TA
/ - -
| - § 7o fºr /"A/oe socket
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|
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SAA/E7'O/W A/7. ze careea oza, on
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/O 7//ecºa's Aer //7c/?.
/"Octagon /)// Steel ,
C///SEL A/7. |
Z // |
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PRINTING Coy, RE,M/OB,283O.











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.







































































WORTH APED HOUSE AU/WWY //U7'CH'
GEOLOGICAL SECTION FROM GIVENCHY TO CUINCHY.
SHOWING MINING CONDITIONS.
CLARGES STREE r
BO/WD STREE7
SHAFT
SHAPT
SHAFT
SHAR-7-
Cove/v7/?y
RED DRAGO/W (100 ya's East of
SHAFT.
|
/00 feet above Sea Leve/
AEED SANDY 10AM
SHAP 7.
Surface of ground + /
3/8 feeſ above Sea
-— Zaſlemand" \ ^
CRA TER
Line of Sectfoo)
A'Ailway EMBAwkmew7
Bºſch Szack.
ſºve/
- /\
- / \\
, N\ // \\
/NA
!, z N \
//
/ z \\
/ N\
/ \
^\\
//b/6MWE./Wo/Aope Wo.J. BoA'E /Wo%m/E/WaAEBoºf
A. Mö. a. 3. 5. A./5.d./O.O/ A.22 a./.3.
- - - - - - - - -/20/eet Above Sea /eve/ .
Somewhat water bearing. |c C --- -
— tº A | | T- |
CYPRINA BEDS {4. , 2 . ------|--|
Loamy sand with | x} ºf xi x *:::::: |
thin band of sand- 4–4– 4-º-º- A/VAL. |
stone at top. Water º º º - - | W:
Z Z |
seeps from base of º % º AP 17. A | º
these sands. % º - ECAA/7 AL.LUſ//4L |
4 º
Z -
4 * % 7. |
& 4 || 4 g/22, % . . . . . . . . . . . . . . . . . . . . . . . . . .32 fºl || Probable
ARG/E OF LOUV/L º ż % *
Zooeboza #4 Lowv// Cray- 59 Feet. A., |
Axistina Gaſſerty @
30feet Awo tº "4 4 Sump Of …"
| % boº/, /*
- LT II | I --- --- - - - - - M. % // |
-- - - - - - - - - - - - - - - - - - - - - - - - - - - oweers Mºve //
| Clay SHALE s \ - –"
- Bottom of bore in chalk. |
\ ºf:
CHALK w/THOU 7 FZ/W75 Bottom of bore in surface Water rose to top of bore Chalk //rhour Filmwrs |
7 f chalk. When chalk
. . .." ...”. and was still under con- |
ru -
top of bore-hole and even siderable pressure.
there was under consider-
able pressure.
These levels, as reduced, now
connected to “Lallennand ” /*ee & /OO O /OO 500 /000 /5(20 Aeed:
Bench mark at school in Harley H=H== –– | | ! -- - – -
Street, -S. of La Bassée Canal at //0/?/ZO//774/ SCA/A
Pont Fixe. /*ee & /O O | 50 /00 ſeeſ: /Woye C = Coſſar frame
L l l I | I | lº !
- -I-T-I-i-i-t-t-t-i T- ºt TVEF7/CAZTSCAZAE
Jea /eve/ - -------------------------- _______________________ _ _ _ _ _ _ ________________ _ _ _ _ _ _ _ _ _ __________________________ Sea Aévé/
INDEX.
Recent alluvials, chiefly red sandy
loans.
Cyprina Sands, with a little clay.
These are water-bearing and part of
the Thanet Sands. The fossil shells
(Cyprina) occur at the point shown at XX
3.
Louvil Clays. Hard greenish black clays and mudstones. These
are mostly impervious, even in the case of the mudstones, which
are about half sand and half clay; and in spite of the fact that the
water in the underlying chalk exerts a considerable pressure
against their base, they are quite dry to within less than a foot of
the top of the chalk.
Upper Chalk, without flints, containing
water under pressure equal to a head
probably of about 20 to 25 ft., i.e., the
water would rise to that level above the
top of the chalk, if tapped in any shafts
or bores within this area.
NOTE:-The water at the top of the chalk under the Louvil clay is under
such pressure that it would at once inundate any galleries in the Louvil
clay, if they were to break through into the chaik. The mudstones are
fairly impervious, though slightly less so than the clays. It would be
desirable to leave not less than 6 feet in thickness of mudstones between the
bottoms of the sumps and the top of the chalk.
Pºwing (ºf W9%









RELATION BETWEEN SEASONAL VARIATION IN LEVEL OF UNDERGROUND SURFACE OF WATER IN CHALK, Fig. 3.
º AND LOCAL PERooLATED RAINFALL.
Chalk Water-Level Curves supplied by M. Malatray of Compagnie des Mines de Béthune.
*
* //enght above sea leve/
+O metres
//e/ght 360 ve Sea leve/
40"oo
------
--- INDEX.
Level of the underground surface of
3o"oo -T ºr TN Y-----__-- the water in the chalk, at the times
- - - - - - - = indicated, at the following Collieries
-- in the concession of the Béthune
FOSSE Mºs
3O metres
FOSSE 7.
Fºss- Coal Mines.
FOSSE N9
4. Fosse 3. -
- - Fosse 4. -
2O: 20 metres. Fosse 5. _-------- **--~~.
MAY JUNE JULY AUG. APRIL MAY JUNE JULY AUG, SEP, OCT NOV bec JAN. FEB. MAR. APRIL MAY JUNE JULY AUG. - - DEC. JAN. FEB. - MAY JUNE JULY AUG. OCT NOV. DEC. JAN. MAR APRIL MAY Fosse 6 _-_TN—º
1904. 19C)7. - 1908 | - 1909 1910 --~~~~
Fosse 7.
Fosse 9. –T
Porticns of rainfall lost by
evaporation.
Nº.6
Mºs
Fosse Ayd
-----
- Portions of rainfall discharged
by rivers, springs, etc.
^ --
-
FOSSE Ayo N-
30"oo _\---ºf J \,\ is Tº Zºº / / ... Nº T---_l-` Tº ºil- Z ~ / \ \-> T wºº.
30 metres Portions of rainfall which
º
- percolates.
/00/7 ºn.
Fosse tº 4
5omm. /24//w/A// Joaza.
20 metres tº om.m.
2O:
man. April May June July
1916
FEB.
OCT. NOV. DEC. I JAN.
JAN. FEB. MAR. APRIL MAY June
1914. 1915
MAY
APRIL SEPT. OCT. NOV, DEC.
JUNE JULY AUG.
JULY AUG, SEP CCI. NOW. DEC. FEB. MAR. APRIL MAY JUNE JULY AUG, SEP OCT.
1910 19|| 1912 - 1913
DEC. JAN. FE8. MAR.
Pºwra's Cox, Æ.A. Wos/2736,













































































Krica/jcak. -
ſee/ Za Aassé,
200, 6/ Vºvchy Cºal.
|
i
/00 I
--~~~
Hoheavzoz. A Áoa
A/V OAA* 7%//a/rea.
Åsoopaz &ooper "
I |
-
|
|
| I
SECTION FROM GivencHY Lez La BAsséE to VIMY RIDGE Fig. 4.
SHOWING
SEASONAL VARIATION of UNDERGROUND WATER
IN THE CHALK. Kºrſca/jcak.
Way &106 ſee.
Aorizonfo/5caſe, --500
Jaras. *** | 1 || 1 f ºpe 2 odo - stee ºve afee *fe 72ao 6 oo o 9doo •oee yards |-
500chez
A/WEA "T-__400
Aoſs ex
Wºr - I
Ara. Jame Aache | -
- 42AT - -
-- Z 2^4.774. |
A. Oos Whe /Jovate Č * _500
- - - - A LO/V/VE. - -
4/470 Crass/ºx (.of SA. Whe ſºmeº Crass/AA. t - -
i I | f
t | | - | -
| I l | | | -
| I 2^
| | - -
//v/.49ch, I | - – 200
i
I | - C- -
|
|
| |
I |
_32nina Aaſer/eve/ -
Zafe Aſoſororo Water Leve/ - - - . - _/90
- *==
PRINTing Cox, R.E.WOB,2759.
- - - - - - - - -
- - - -- - - - - - - - --- - --- - - - - - -- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
- ----- - - - -- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Hºº
_ 200
Åecen/. --- Thameſ - / ovviſ Chaſk whew - Chaſk
| 5andſy CaZyº. 5.and Clay & awſh//hſ. - //ará. __ 300
fervous /ropervious.






SKETCH SHEWING VARATION OF CHALK
WATER LEVEL Loos To CANAL D'AIRE
NEAR GIVENCHY LEZ LA BASSÉE.
VERTICAL ScALE.
3OO FEET.
T
- 200.
H 100.
GIVENCHY.
:- || H 1910 THE VARATION was 35 FEET & IT was PROBABLY
AT LEAST As Much in 1517.
-
u \tº SPK,
v ENº. I
Algº whº "...ºral Range º
Low water LEN F. " MON
EMBER.
tº Yºº-
FOSSE 5.
MAROC heaR Loos.
- 226 FEET.
PRINTING Coy. REWOB,2828
SANDY CLAYS.
CLAY.
- | 2. 3. S. MILES.
| l l _l
HoRºzoNTAL SCALE.
|NDEx.
CENT LOUV) L
RECENT CHALK.
— SEA LEveL.
O.
Fig.5
SKETCH SHEWING VARIATION
IN WATER CAPACITY OF THE
THREE CHIEF TYPES OF CHALK
ON WESTERN FRONT.
THE Figures show YELD in
CUBIC METRES PER HOUR
From Collery SHAFT
6 METRES IN DIAMETER.
24
3. CKALK witHouT FLINTS
VERY FULL of water.
2. CHALK witH FLIt{TS
CARRYING LESS WATER
THAN THE ABOVE.
- - - HARD CHALK. SPRINGS
BREAK OUT HERE.
| CHALK MARL cARRYING
MUCH LES5 warER &
Ori LY in LARGER F 155 URES.




SECTION showing GEOLOGICAL STRUCTURE in the - Fig 6.
MINING OFERATIONS artween VIMY RIDGE AND
" THE PIMPLE "
THE PMPLE THE OBJECT WAS TO KEEP THE OFFENSIVE TUNNEL IN CLAY A5 FAR AS POSSIBLE SO A5 W
fnemy's sirong poin's close TO SECURE SLENT WORKING WHEN APPROACHING THE ENEMY5 POSITION. |MY RIDGE.
/o her fron? line frid of funnel
| on April 9, 197 MARQUEFFLES
| Fol-D
— AND FAULT5 Sandy Clay.
| - (ſimon)
Thaneh Sand. - D5. Shaft
| %-
- - –, % _-T
Los y | Cla 5 *~zz. –/_ 7 _- -
and º; + | 2 * T
ſ
º
Chalk º loy #.
withouf A Bohom of D5. Shafh |
Flinks. | |
97 ft. - #
Chalk | |
with 53 +
F/in/s. |
- - f _
* 7tury' ~ |
hard chalk - - - - 69 fr
Wºh fliºs-T- |
• * * e_2_2_2 e—sº a , e-º-º:
• * * *
Chalk 2 tº
- ->
Marls. / 2 e_2
- --> a 3.
_-
- _-
_Sea level - ____________________________Sea level -
'Djèves' - -
b/uish grey
Marly clays.
While
Marly -
Chalk. ...e.”
- .*.
- - ->
'700rha'. greensand .*.*, *. 2 º, sº sº e” e = * * * * - * c e º ºxe = z_*-a-º-º-º-º-º: • *, *s, *2 = a + c e s ºe •o * c º
Devonian.
Horizon/a/ and Verfica/ 5cale.
AR/w//wg Coff/Wob 2758. * , , , , *, , , , f º ** ** ** * feet.

SECTION SHowing MINING OPERATIONS UNDER OLD RIVER CHANNEL we
º
BETween ONTARIO FARM AND BOYLES FARM NEAR Foot OF
MESSINES RIDGE.
On/ario farm. #2%..., ź.
_-- à
à
5andy Clay º
Qvalernary Moſer bearing 5ands à
2
//aſer-bearing 5ands. à
º
2
2.
2 _
2
2
Running 5and commenced
ſo break ſhrough roof of ſonne/ *
= ... -- *º-ſºº * –- à -
Mſ. Boe Cay (ſoresar) T-- 2 =º A/ve Cay (Yoresſon)
” a
5ea /eye/ 5ea Zeve/
horizon/o/jcaſe.
A. f 22 o woo *22 ºod 4-oo 5oo
Verſica/ 5ca4.
A2/wz/wo CºA. WOA/2/56 25 o 25 5o zº 4”
Aeef l-i-Il-t-t - E




Wytschaete
Wet Recent d
(a) Recent Valley sancis
Alluvials
- |Moist “Hesbayen'' sº
Post-Tertiary. (b) Grey "limon" -----1 clays
Alluvials i more or less sandy Lower Lower ſo
y --
Eocene - Eocene : Ypresien.”
- - -- ºr -- - !" lay
Wet ... ... “Campinien'' Paniselien” Wet Kennnnel Ypresien c
-: *.*.*.*.*.*.* (c) ... and formation sands formation
greenish grey
clayey sands with
gravel at base Moist El Sandy clays
to Dry overlying
––– stiff clay
|A |
---
HILL 607A CATERPILLAR -
Depth90Fe
p Depth 83Ft.
~~ Cºoen &ngs
Tºowºff fººt-
ºy sand ſº dº
-º-º-º-º-º-º: %res Comnes
ºmºsº.
Cana/
Cayey Sºnd-
*%;" Cºy - Fºs-
º/ ---
--
Vertical Scale
FEET
HollandscheschuuR
z----- is __ ===-\\ *
SECOND ARMY OFFENSIVE MINES 7–6–1 7.
Geological Section through Craters
Hill 60 to Ploegsteert.
LIN E OF SECTION SHOWN ON MAP B.
5 7
MAEDELSTEDE § SPANBRoekMolen
FARM
Peckham
Depth 88ft
Depth96ft Mytºchaetejands
4A 48
3° 3% PETIT Bois
n°3 No 1
peºnggit!”ft
sººn rºº
º: - E. º --- ------------
22 25 Aºoſseſ/eº Cºy
-Tº- -----— — — — — — —
Post-Tertiary.
(a) Recent Valiey
Altuvials
|Moist | Hesbayen''
--- (b) Grey limon "
more or less sandy Lower
Eocene
“Campinien.” "Paniselien” Wet
KRuisstraat
- Ontario FARM
cºs
-
- - - -
-
L(c) Grey sands and formation
greenisºn grey
clayey sands with
gravel at base
SECTION C.
Fig 10.
Wytschaete
sands
Sandy
clays
Lower ſ
Dr.
Eocene y - "Ypresien.”
Kemmel Ypresien.” cíay
| sands formation
* Sandy clays
overlying
stiff chay
SOUTH
ºf T T ~ --------- ~ – ––––
2–––
zz presendº
Belgian datum, ſevel of low tide
4. woo zoo 257 500 Z30 º 250
Horizontal Scale
Pº/7/WG Caº R. E. W.08/ 27.3/
PETITE Douve
º
SEAForth FARM
--~~
º Dogwe Depthſ?Uſt-
- - -------------
- - ...:*
- - - ... s.*.*.*** º” -
* - -
|
__ _ _ _ _ _
750 food /257
—l
|Óð
|A
Tsench 127 TRENCH 127. T || 3
REnch!
N97 lef N28tight Nch 22 TREncH122
* / left N95 left
Nº 6 right
Depth 75Ft. Depth 76ft
f TV Depth 77F:
º-
T-- Depth 58ft
- \ - *
* Æesday&n
---
_-- - -- A 4///vºs.
- -
- - - -
/750 * yards
1
Horizontal Scale.










































VERTICAL SCALE.
SECTION
TRIPOD.
Pipe i.d.
:
SOUTH
AcRoss YSER
SAEAve witH goPE SUSPENDING PIPE.
Col L of Rope.
REFERENCE.
d. WATER Swivel.
el. STRAINER OF INTAKE PIPE.
PUMP To SUPPLY SUMP
3. Surº P
h.h. Two "Low Down double Acting purps
6" ST ROKE 5" i.d. BARRELs witH THE
LEVERS COUPLED BY CROSS BAR m.
220 FEET.
CANAL AT NIEUPORT.
SHEWING METHOD OF BORING THROUGH QUICKSANDS WITH A WATER JET.
f
<
T- O. FEET
BLACK CLAYEY -
50 L. N
N
T 10. -
Pol-peg CLAY.
—H· 20. -
0. BELGIAN NIVELLEMEriſ
GENERAL DATum. -
+30.
FINE GREY SAND
+40. witH THin searts of clay.
-H 50.
—H· 60.
COARSE GREY SAND
+H 70. witH 5HELL fraGMErits
& Lignitised wood.
–4– 80.
- |- 90.
BOTTOM OF 3" CAS)n G.32' 6"
-HH-100.
BorroM of 14 P.
YPRESIAN CLAY.
—li- 110. FEET. *- A STEEL Rop.
A2//wg ("/24 W08, 2%2
12. " AUGER.
YSER CANAL.
- -- - - - - -
Borton of 5" casing.
_*-
T-
Borron of 1%. P. PE.
YPRESIAN CLAY.
Fig. 13
NORTH.
Ö..
W
/ - In DIA RuBBER
- HOUSE.
Ç
º
s
S
s &
Fine GREY SAND.
= SEAM of Pol DER CLAY. 3.
Fine GREY SAnd.
= 5EAM of Polder CLAY.
Fin E GREY SAN p.
- SEArt of PoldF.R CLAY. 3."
Fine GREY SanD.
|- SEAM of PoldeR CLAY3.
40. --
44' =
COARSER SAND witH FRAGMENTS of REcENT & Estuarine SHELLs.
5O. — |=s. of PoldeR CLAY 6.
COARSE GREY SAND witH shel-L FRAGMENTS & Lignitised wood.
63. −1ſ− SEAM OF POLDER CLAY 3:
CoARSE GREY SAND with SHELL FRAGMENTS & LIGNITISED wood.
A steel Roo.
s2. ; I" Aug Er.
























SECTIONS SHOWING FAULTS AT ScHERPENBERG.
Fig. 14.
WHICH LED TO THE LOSS OF GALLERY B THROUGH INFLOW
OF RUNW/NG SANDS. GALLERY A AND ITS SYSTEM OF DUGOU7.5
REMA/WED DAY.
D/EST/AAW FERRUG/WOUS ASSch/AN CLAYS LED/AN
|N D EX 54A/OS W47 ER BEAR/WG. //MPERV/OU/5. SAWDS.
º
HORIZO/W7AL 5CALE
- AEE7 foo 5.o C2 /Oo 2Oo Eoo
L 1 1 | | | | | | | | |
upſ:59 2. Ø
- foo F-57. VERTICAL 5cALE 3. ** T“Søg
Cy^ >~ -
Sºč2.
2. $32
/ 3. -
Čz *
Vºž/ N
- 80 6% N
& / YSS
X `SS
/ N.
/ N
2^ N
L 60 2^ N WET SAA/O5 -
2^ N.
/ SS
DRy CLAY \
N.
54.57. 2^ \ WEST. SouTH.
Z ^
WE7 SAMD.5 f7 5.4//05
–40 2^ WET SANDS 7 S4 W.
,”
2^ N DRy CLAY
2^ N
2^ SS - |
| 20 Dºy 34//05 N
2^ ANA’Y CLAY /)
Ary
SAND.5 ARY CLAY |
100 me/res above 24-T ---------------Zevé/__2/__** – ‘-----------— — — — — —---- N. T--~ -- Caſan Zine.
J. - - - - - - -
ea Leve/. DA’Y SAA/OS SS _^
T---------__ MA/W Ro4D Tºss MAN APO4D
-- N. *- -
TT----_ S FROM LA C/Y775 FYOM A4 Cly TTE
T--———— §§ A4/// A UL Oºy SAMD.5 `s DRY CLAY To BA/LLEU.
T- ~ N- -
Az///7/609/2A.//7 42/33































MAP ShowINg Positions of CHIEF
SUBTERRANEAN ExcAVATIONS (SouTERRAINS)
IN NorthERN FRANCE .
-
* - - - -
A/º ("PAA. WOA/2829
tº V//ages oa //exºsk.
aes Joa/errains
@ Beſhane
- - -
G)\º * ~
--~ Mon/rea;7 * ~ *
T-F * ~ * -
SEA * -
Eſsº - ſe - R. -
- Auſº
--s -
== evron * //awſ: Aresnes
–Esse Grue - - º,
- =s= crºsy Guischa ** ARRAS -
Fsº ke Croſo - G. ſ way-/e- Chaſeau Goºy *..., hter: º
T--> Sº e Fores” - •: - £ºº, - ...
-E GR R Wowºn e &: *issa. Poºh, e. warasiº ºwr- alººk \
T--> 3r Velery N - * **werrºcº sºlº *R*, *,2,…, *
- *:::::::::).Mºrenchcak Doulléasºever - CA/7BAPA/
- Maº'º' ſee - - & Ž ſºonch -aa-3ers
- sº • 57 8ſimoniº Stºod. *...*& * Provºſe caugºn; :::::::ſºs Cy *Ery,//
E N $º Doº? ºgºnes *ºso, ##: ©ºeëaſerne rviſers -
EP Asseva. A2S ...”...ºft.*śarºscº. \
- == 4. - &º". 8.º: A.Ž% Bała/ *Marvel, Serre (3) BAPaunts -
Esº &nt Remº e % ornar/- *śazzº. anºumenºne - t
EP ºv £ier: *...Beaucar, *ainchezay •ſhal/y • 8/avancour/* w
- erroº, Wºffers As • *.*, *Force/. t
N- •/ae, ºvº..”/ers’ “” t
N- - Aſ % oars rºe *aroonythe -
ºğamarſzes arºſen tower Kº: **: *en- º Warſay t
- ºnacow -
\, r º *:::-8ecae. 2.8, 3A/0er/
\os/ a.º...”…º: Br t
Sangy *> rſangſeº Ribemonſ ºf t
9 SS N g - --- º - ZT P I
(brólel. OA’ercrºme t
M. Horney O –2- S-ºs
- - - A M - g S-S-2 certsy
Y Que *wr/ers Yºſſa. & *1a. 177ame
+ © --> *5-tºe/coneur *///arce/eave
Sºs *enaea, e. olt hons (C)
R. *32's ". °Chau/nes r
AUMALE& ºx - ferºcocºrrº" t
$'aº.º.º. RMoreº °ſcouesnerºansa-r !
- G C.orm ſy e/Han -
". - - - posſ ºf arºſſers G t
- Aſſy-In -Moye 4-a Mºvie A: *Bouchoirs //an, t
". 2 rwthers Gº f
d -
. © MowrD/ f
. - D/ER Chaun r
. ©&re/.eczz/ ) y £y
&Gerberoy
- - - -
- -
-
- -
- -(3) BEAUVA/S
* -----(s) Clermon/
-
- - - -
3.
-- - –
- -*.
--> -
- - –-
- --
- ºr
§§ NRF
º N -
§ - -
-Nº
--
-
- c. : :
- .
- - -
- - : : :
N. N. - - * :
Nº - - # ,
--" - -" -
NS - T- - --ſ . . .”
N N *-
N N - -- - - - -*...* *
N - N § --- --- - >>
GAPENNEs.
4%g/se ºf as
- Jouſerra/m3.
/*
Z
2 ”
2^
Czzerº-z-z-zº,
º c/
W
wº-
*/Vºzso,
* AE & Azz//zrºy
4.
-
Fig. 15.
<24-45, ov
CAR4/34.5 c5?-
A 50.
//</ A#,
ARRAS
CAVES & SUBWAYS
Seaſe zº ZOOOO
/7 Zoo a
ºc, C. zºo’e”
L ---
|
f
-->
-->























MAP OF WATER SUPPLY.
Portion of NAMUR SHEET. 1/100,000,
- - Rºžº sº. -
* tº: ºgº.” bºº
-->
º--~~~ -
-
- º . --. º -: - |-º- ºy - -
- Dºg/rº - Cº-ºººoo-ºº: * * *
|--|--|-- 7t- ------ º, º -
I Sºº-ººſe: sº
- £ºgºź” º
_- cº- *-*. º
º - - º
a.º. --- 4.
--- - |- ---, -º
Bºº Sºejº
--- º SA º
o,99;
Supp/Wºº "
...(3)
---
ºAsºº ---
S-Wºr:
S
, ſº
º
-
%3rºe Cºncºſ º
"Y-º-º-º-º-º-º: ---
- - - -
- º As - - reſº: - - º
- ſº º º ºo: - 33 ºC º 3. f* - ºf- [. -
T-1 o: º Cºoes, Gr %\S *
- tº gº ana’,º º \
---
-
-
-
.
-
º
º
º
º
ſ
-
º
º
- - ". - | --- - º º º º *|| - "ºr . - * - - -
- - - --- - - - - Zºº Cºº/r/ſº O/T. S.207,º - - º
- - w - - T - - º º - - !. ". Ž º “. . º - - - º º - -
º \ - º Woºttº 350m. 22. - *. rº-sº º - - - º- º
ſº \ 5/ºoe.Sºcºroº - &eeo. - EºPºre º
G.S.G.S. 3720, in Summer
Æor explanatory notes see Text under Water swºoſy maps
Zºº
. ača-2 ra. º -
####23
ordnance Survey, February, 1919.
2-Wºodºº
-














































Neuville St. Vaast
Manoeuil Aux Reitz Bore ->
** =
R. Scarpe º
º
Upper Chalk
Bleus Middle Chalk
- Q- - --—-TT ____ _ _ _ _ _
Devonian
N.E., S.W., Section
Aa/w//yo (29/2A, %3A423
Eſ
La Folie Farm
//A.
F. No I. F. Nº 4-
de Vimy
DT
F. Ne5
de Liévin
S
de Courrieres
c º Canal de Lens
Nº. - - ---
SJer 3ry - ----
Upper Chalk **C. Tº s -
-------- *— — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — —0.
Tun — -14. -19 -17
Bleus . TMiddle CFSIK -3
Dièves, -
-52
– 96 Lowen Chalk
- 14.
Devonian
-
-113
Coal
Measures
across the Vimy Ridge.





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