Chapter IV: The Mark I Tank and Its Tactics

The Mark I tank was the direct produce of the experimental machine which was officially tested on February 2, 1916. It may be defined as “a mechanically-propelled cross-country armoured battery,” the maximum thickness of its armour being 12 mm.[17]

The main tactical characteristics of all tanks may be placed under the headings of--mobility, security, and offensive power, and as regards the Mark I machine the following is a general description of these characteristics:

(i) _Mobility._--The Mark I tank could move over flat ground at 100 to 120 yards a minute, over ground intersected by trenches at 30 to 40 yards a minute, and at night time at 15 yards a minute. It could cross all forms of wire entanglements, crushing down two paths through them which were passable by two single files of infantry. It could span a trench 11 ft. 6 in. wide, surmount an obstacle 5 ft. high, and climb a slope of 1 over 2.

(ii) _Security._--The Mark I tank was proof against ordinary bullets, shrapnel, and most shell-splinters.

(iii) _Offensive Power._--Mark I tanks were divided into two categories: male and female. The former carried an armament of two 6-pounder guns and four Hotchkiss machine-guns, the latter of five Vickers and one Hotchkiss machine-guns. The normal amount of ammunition carried was for males 200 rounds and 10,000 rounds S.A.A., and for females 12,000 rounds S.A.A.

The chief limitations of the tank are connected with its mobility. For the Mark I type these limitations were as follows:

Its circuit in action was about 12 miles, and the fighting endurance of its crew 8 to 12 hours. It was not suited for traversing swamps, thick woods, streams with marshy banks, or deep sunken roads. It could be expected to cross shelled dry ground at a slow pace, but should this ground become sodden with rain it would find difficulty in doing so, and might frequently become ditched.

A tactical paper on the employment of this machine was put forward officially in February 1916 by Colonel Swinton, entitled “Notes on the Employment of ‘Tanks.’” This document is of special interest as it is the first tactical note published on the use of tanks. The following are certain extracts taken from it:

“The use made by the Germans of machine-guns and wire
entanglements--a combination which has such power to check the
advance of infantry--has in reply brought about the evolution of
the ‘caterpillar bullet-proof climbing motor, or tank,’ a machine
designed for the express purpose of assisting attacking infantry
by crossing the defences, breaking through the obstacles, and
of disposing of the machine-guns. It is primarily a machine-gun
destroyer, which can be employed as an auxiliary to an infantry
assault....”

“Hostile machine-guns which it is impossible to crush (_i.e._ by
running over them) will be attacked by gunfire. It is specially
for the purpose of dealing with these weapons ensconced in houses,
cellars, amongst ruins, in haystacks, or in other concealed
positions behind the enemy’s front line, where they may not
be knocked out by our artillery, and whence they can stop our
infantry advances, that the tanks carry guns. Being covered with
bullet-proof protection, and therefore to a great extent immune
from the hostile machine-guns, they can approach sufficiently close
to locate the latter, and pour in shell at point-blank range....”

“As ... it is proposed that the tanks should accompany the
infantry,” they should carry forward the following signalling
apparatus, “small wireless sets ... an apparatus for laying a field
telephone cable either on the surface of the ground or possibly
buried 12 in. deep ...” also visual signalling apparatus and smoke
rockets.

“The tanks will be destroyed by a direct hit of any type of
howitzer shell. They will probably be put out of action by all
except the most glancing hits of high-explosive shell fired by
field-guns.... They may also be blown up by mines or land-mines....”

“Since the chance of success of an attack by tanks lies almost
entirely in its novelty, and in the element of surprise, it is
obvious that no repetition of it will have the same opportunity of
succeeding as the first unexpected effort. It follows, therefore,
that these machines _should not be used in driblets_ (for instance,
as they may be produced), but that the fact of their existence
should be kept as secret as possible until the whole are ready
to be launched, together with the infantry assault, in one great
combined operation....”

“The sector of front where the machines can best operate should be
carefully chosen to comply with their limitations, _i.e._ their
inability to cross canals, rivers, deep railway cuttings with steep
sides, woods and orchards....”

Tanks should remain at the position of assembly “sufficiently long
for the crews to reconnoitre, ease and mark out the routes up to
the points where they will actually cross the front defences,
and to learn all that can be discovered of the German front-line
trenches, and the defence zone behind it over which they have to
advance....”

“The tanks, it is thought, should move forward together, say,
by rocket signal, sweeping the enemy’s first-line parapet with
machine-gun fire; and after they have proceeded some three-quarters
of the way across ‘No Man’s Land,’ and have succeeded in attracting
to themselves the fire of the German infantry and machine-guns in
the front line, the assaulting infantry should charge forward so as
to reach the German defences soon after the tanks have climbed the
parapet and begun to enfilade the trenches....”

“... unless expectations are falsified, if the machines accompany
the assaulting infantry, moving with it, or just ahead of it ...
both will be across the enemy’s front line and on their way to the
second before the curtain of fire descends, and the latter will be
behind them. It is hoped similarly that, owing to the prevention of
the usual checks to the advance, which the action of the tanks will
ensure, by the time the German gunners shorten the range in order
to provide a second curtain in front of their second line, our
assault will have already swept beyond the line.

“The above anticipations are admittedly sanguine; but if the
tanks are employed and are successful, it is thought that they
will enable the assault to maintain most of its starting momentum,
and _break through the German position quickly_,” a condition
which up to the present it has not been possible to attain, “even
after immense sacrifice of life.”... “Not only, however, does it
seem that the tanks will confer the power to force successive
comparatively unbattered defensive lines, but ... the more speedy
and uninterrupted their advance, the greater the chance of their
surviving sufficiently long to do this. It is possible, therefore,
that an effort to break right through the enemy’s defensive zone
in one day may now be contemplated as a feasible proposition....
This being the case, it appears that when the tanks are used the
contingency of such an extended bound forward being made should be
most carefully legislated for in the way of preparation to send
forward reinforcements, guns, ammunition, and supplies....”

“The necessity for the co-ordination of all arms to work together
in the offensive generally requires no remarks here, but the
desirability of the specially careful consideration of the subject
in the case of an operation by tanks, requires some emphasis,
since the orchestration of the attack will be complicated by the
introduction of a new instrument and one which somewhat alters
the chain of interdependence of all. A recapitulation of this
chain will make the matter clear. The tanks cannot win battles by
themselves. They are purely auxiliary to the infantry, and are
intended to sweep away the obstructions which have hitherto stopped
the advance of our infantry beyond the German first line, and
cannot with certainty be disposed of by shell fire. It follows,
therefore, that the progress of the attack, which depends on the
advance of the infantry, depends on the activity and preservation
in action of the tanks.

“The weapons by which the tanks are most likely to be put out of
action are the enemy guns. The only means by which we can at the
earlier stages of an attack reduce the activity of the enemy’s
guns, are by our own artillery fire or by dropping bombs on them
from the air.

“It follows, therefore, that in order to help our infantry in any
operation in which tanks take part ... the principal object of our
guns should not be to endeavour to damage the German machine-guns,
earthworks, and wire, behind the enemy’s first line, a task
they cannot with certainty carry out, and which the tanks are
specially designed to perform. It should be to endeavour to help
the infantry by helping the tanks, _i.e._ by concentrating as heavy
a counter-fire as possible on the enemy’s main artillery position,
and on any field or other light guns whose situation behind the
first line is known....”

“In order to increase the confusion which it is hoped will be
caused amongst the enemy by an attack by tanks, and to assist in
concealing the exact nature and the progress of these machines, it
would be of advantage if their advance were heralded by clouds of
smoke....”

The above quotations need no comment, and if comment is to be sought for, the most suitable places to seek it are the battles in which tanks eventually took part, for in these, and the great number of lesser actions, some eighty-five in all, it will be found that not only were Colonel Swinton’s speculations, made seven months before the first tank crossed “No Man’s Land,” not mere “flights of imagination,” but “solid facts,” the value of which these battles have proved again and again.