TANK TACTICS
The training of the Heavy Branch having been laid down, it was next
necessary to discover and decide upon a common method of tactics,[21]
so that directly individual instruction had been completed collective
training might be based on it; further, rumours were already afloat
that the Heavy Branch might be called upon to take part in the spring
offensive, so there was no time to be lost in deciding upon suitable
methods and formations of attack. This was done early in February, when
“Training Note No. 16,” which will long be remembered by many in the
Tank Corps, was issued.
Though experience is the only true test of a system of tactics, the
foundations of the tactics suitable to any particular weapon are not
based on experiences, but on the limitations of the weapon, that is
on its powers, and on the fundamental principles of war. Further
than this, if the weapon concerned is to be employed in co-operation
with other weapons, the powers of these other weapons must also be
considered, so that all the weapons to be employed may, so to speak,
like a puzzle, be fitted together during battle to form one united
picture.
In thinking out a tactics for tanks, the first factors to bear in
mind are the powers of the machine, which may be summarised in three
words: “penetration with security.” Heretofore fronts had remained to
all intents and purposes inviolable to direct infantry attacks; the
tank was now going to break down this deadlock through its ability to
cross wire and trenches under fire with far less risk than infantry
could ever hope for. Mechanically, the machine was far from perfect,
consequently, it was laid down, as a general rule, that never fewer
than two tanks should operate together, and when possible not fewer
than four.
From a military point of view the penetration of a line of defence
does not simply mean passing straight through it, but cutting it in
half, and then by moving outwards as well as forwards to push back and
envelop the flanks thus created and so widen the base of operation to
admit the movement forwards of reserves and supplies, and the movement
backwards of casualties and tired troops. A man getting through a
hedge first selects a weak spot (point of attack), he then forces his
arms through the branches (penetration), and pushing them outwards
(envelopment), forms a sufficiently large gap (base of operations) to
permit of his body (army) passing easily through the hedge (enemy’s
defences).
The operation of penetration with tanks is just the same. Take a
half section, two machines; this half section first penetrates the
enemy’s defences by crossing them (see diagram 7), then by moving
outwards, say to the left, starts enlarging the base by driving the
enemy towards A, and so makes a gap between the point of penetration
and A, for the infantry to move through. As the enemy may, whilst the
tanks are working towards A, seek refuge in his dugouts and “come to
life” again after the tanks have passed by, it is necessary that the
tanks should be followed by an infantry “mopping up” party which will
bomb the dugouts and so render “coming to life” less frequent. As the
bombing party has to work up the trench with the tank, it cannot hold
the trench once it is cleared, consequently another party of infantry
should follow the bombers, whose duty it is to garrison the trench on
it being captured. We therefore find that even in the smallest tank
attack two parties of infantry are required: in trench warfare these
are known as “moppers up” and “support,” and in field warfare as
“firing line” and “supports.” Frequently it is as well to add another
party, a “reserve,” so that some definite force of men may be held in
hand to meet any unexpected event.
[Illustration: Diagrams 7-12]
If instead of two tanks we use four, a much more effective operation
may be carried out. The tanks can either penetrate at one place, and
wheel outwards by pairs (see diagram 8), or by pairs penetrate at
two separate points and wheel inwards, pinching on the centre (see
diagram 9), or two can wheel to a flank and two proceed straight ahead
(see diagram 10) and threaten the enemy’s line of retreat. When this
latter operation is contemplated it is as well to make use of at least
six machines, better twelve, _i.e._ a complete company of tanks. If
six machines are used they normally should strike the enemy’s line
at approximately the same place; from there one half section should
go straight forward and one to each flank, forming what has been
called the “Trident formation” (see diagram 11). If twelve machines
are employed, then each section of four tanks strikes the trench at
a separate point, the centre section forging straight ahead and the
flanking sections moving inwards and outwards as depicted in diagram 12.
Particular attention should be paid to the outward movements of the
flanks, for, as the flanks of our own penetrating or attacking force
are generally the most vulnerable points, if we can push forward
offensive wings on these flanks we shall not only be protecting our
own flanks from attack, by giving the enemy no time to attack in, but
we shall be protecting our central line of advance as well. The force
operating along this central line not only depends for its movement
forward on the security of its flanks, but also on the size of the
base of operations; the broader this base the more secure will it be,
for the one thing an attacking army wishes to avoid is getting into a
pocket on the interior of which all hostile fire is concentrated.
[Illustration: Diagrams 13-15]
From the above elementary movements can be worked out a whole series
of battle formations according to the various arms which are to be
employed. The following three were those generally used by tanks from
the battle of Cambrai onwards:
(1) _An attack against trenches with an artillery barrage_ (see diagram
13).--Three tanks in line at 100 to 200 yards’ interval, followed
by infantry in sections, each section forming an independent fighting
unit advancing in single file and attacking in line, the whole forming
one firing line. Behind this firing line should advance one tank and a
certain number of infantry sections as a support. Reserves can be added
as necessary.
(2) _An attack against trenches without an artillery barrage_ (see
diagram 14).--One tank in advance, followed at a distance of 100 to
150 yards by two others at 200 to 300 yards’ interval, and one tank in
support. The infantry should be disposed of as before. The advanced
tank to a certain extent replaces the artillery barrage and acts as a
scout to the two behind, which form part of the infantry firing line.
(3) _The field warfare attack_ (see diagram 15).--In the field attack
the action of the tanks must be adapted to circumstances. This action
falls under three headings:
(i) Moving in front of the infantry firing line.
(ii) Moving with the infantry firing line.
(iii) Moving behind the infantry firing line.
When moving with the infantry firing line, which will generally be the
most suitable formation to adopt, tank sections should form mobile
strong points or bastions, which will not only reduce the number of
infantry required for the firing line, but which will be able to bring
oblique and cross fire to bear in front of the advancing infantry. In
order to reduce the human target as much as possible without reducing
fire effect, Lewis-gun sections should freely be used to cover by fire
the intervals between tank sections. These Lewis-gun sections should be
followed by rifle sections which, directly opposition is broken down by
the tanks and the Lewis gunners, should move rapidly forward several
hundred yards in front of the tank and infantry firing line, forming
to it a protective screen of sharpshooters. This formation should then
be maintained until the rifle sections get hung up, when the tank and
Lewis-gun firing line should pass through them to renew the attack, the
rifle sections forming up in support in rear. Curiously enough this
formation resembles very closely that generally adopted by the Roman
Velites and Hastati (riflemen), Principes (Lewis gunners), Triarii
(tanks), and Napoleon’s Light Infantry (riflemen), Infantry of the Line
(Lewis gunners), Old Guard and Heavy Cavalry (tanks).
As an infantry attack depends on the following principles--the
objective, the offensive, security, mass, economy of force, surprise,
movement, and co-operation--so does a tank attack. The tank must
know what it is after, it must act vigorously, it must be protected
by artillery just like infantry, it must attack in mass, that is in
strength and numbers, but not, necessarily, all in one place; it must
surprise the enemy, move as rapidly as it can, and work hand in glove
with the other arms. On the application of these principles to the
conditions which will be met with will depend the success or failure of
the tank attack.
The first condition to inquire into is the position of the objective;
is the ground leading up to it suitable for tank movement, is the
country on the flank of such a nature as to permit of offensive wings
being formed? The second is the position and number of the enemy’s
guns; can these be controlled by counter-battery work or smoke; how
will they affect the lines of approach and their selection? The
third is the number of subsidiary objectives before the final one
is captured. The fourth is the “springing off” position of our own
infantry, and the fifth is, how can the enemy be surprised? These five
questions being satisfactorily answered, the normal procedure is to
divide the whole tank force into a main body and two wings; to take
these three forces and to divide each up into as many lines of tanks
as there are objectives to be attacked; to divide each objective up
into tank attack areas according to the number of tactical points
each contains. Provided the enemy does not possess tanks himself, or
a sure antidote to their use, which the Germans never did possess, a
well-considered and mounted tank, infantry, artillery, and aeroplane
attack is the nearest approach to _certainty of success_ that has ever
been devised in the history of war. No well-planned extensive tank
attack has in the past ever failed, and each one has resulted in
more prisoners having been captured than casualties suffered. These
are historic facts and not mere pæans of praise; they, consequently,
deserve our most careful consideration when eventually we plan and
prepare for the future.