A TACTICAL APPRECIATION
The battle of Messines may be looked upon as the high-water mark of
the artillery attack, which was first developed by the British Army
during the battle of the Somme. The time, however, was approaching when
a change of tactics became imperative on account of the enemy having
learnt his lesson. To appreciate what this question involves is of some
interest, especially so, as in the tank was eventually discovered a
means of overcoming the counter-measures now adopted by the enemy.[24]
The main characteristic which differentiates the German defensive
tactics of 1917 from those of 1916 would appear to lie in the grouping
of their men rather than in the siting of their trenches.
In 1916 the major portion of the German Army was placed in the frontal
defensive belt because security was sought for in the maintenance of an
unbroken front. In 1917, however, this security was more economically
guaranteed by holding behind this front, instead of in it, a large
reserve which could strike at any opponent who broke through.
This reversion to the “big idea” and the abandonment of the smaller
one, namely, that war is a “series of local emergency measures,” placed
a further difficulty in the way of the attacker. In 1917 it was no
longer a question of breaking through a defensive line as in 1914, or
a zone of defences as in 1915 and 1916, but of exhausting the enemy’s
reserves before undertaking either of these operations with decisive
effect.
This could now only be accomplished by hitting the enemy at a point
which he must hold on to because of its importance or of surprising him
at points where he did not expect to be attacked. If such points were
not selected all he need do was to fall back as he had already done in
March, and so dislocate our operations, by temporarily denying us the
use of our guns.
As hitherto, the change we have always most carefully to watch for is
any change the enemy is likely to carry out in his artillery tactics,
and the following is apparently what the German was now doing.
Having learnt in 1916 and the first half of 1917 that if the attacker
makes up his mind to do it, he can carry, by means of artillery and
infantry alone, several lines of trenches in one bound, it stood to
reason that the German General Staff would not continue to jeopardise
its artillery by so placing it that it could be pounded to pieces
during our preliminary bombardment.
If now the Germans withdrew their guns further back to a position from
which, though they cannot cover their front-line system, they can cover
their second or third lines and simultaneously be immune, or to a great
extent immune from our counter-battery fire, by accepting the loss of a
small belt of ground they would place our attacking infantry in such a
position that whilst it feels the full effect of their artillery, it is
receiving next to no protection from its own.
The construction of their defensive systems in 1917 did not altogether
lend itself to these tactics, the systems were too close together; but
should these distances be enlarged the disadvantage to the attacker
becomes apparent; and there were already signs that the Germans were
fully aware of the advantage of this enlargement. At Arras they had
been surprised in spite of the lengthy bombardment and they lost over
200 guns, at Messines they lost 67, and later on at Ypres only 25, on
the first day of each attack. They were, in fact, countering by gun
fire the exploitation of a penetration. This system of tactics can be
graphically illustrated as follows (see Diagram 16).
[Illustration: DIAGRAM 16.--GERMAN ARTILLERY TACTICS.]
Suppose that AB be the German front-line system, and that CD, their
second line, be so placed that the German guns at E can heavily shell
the whole of CD, and yet, on account of the distance away, remain
practically immune from our guns at F. Suppose also that the area ABCD
is strongly wired and well sprinkled with machine guns, who is going to
suffer most--the attackers from GH, who will not only be perpetually
worried by the machine guns and sharpshooters in ABCD, but who will
come more and more under the enemy’s gun fire as they proceed towards
CD, or the enemy’s machine gunners occupying ABCD, and his infantry
in dug-outs along CD? Undoubtedly the former, for they present the
largest target, and against them is being thrown the greater number of
projectiles. Suppose now the attackers capture CD, then at best they
will only be able to remain there as impassive spectators to their
own destruction until such time as the guns at F move forward, which,
on account of the “crumped area,” ABCD, will take many days. This is
probably what would have happened had the Second Army been required to
push the attack from the Oosttaverne line towards Wervicq.
Except for an attack on an objective of very limited depth the
artillery attack was almost doomed to fail on account of slowness of
moving forward the guns, due to the destruction of roads and terrain
during the initial bombardment. Bearing the above possibilities in
mind, it was with some apprehension that the Heavy Branch watched the
approach of the next great battle, for though the “crumped” area could,
if dry, be crossed by tanks, whatever service they might afford would
be rendered useless on account of the impossibility of keeping the
attacking infantry supplied; to do so, fleets of supply tanks would be
required, and these did not exist.