"The _rôle_ of artillery is to assist the other arms in breaking down
opposition, and to afford all possible {169} support to the infantry,
with whom the eventual decision rests" ("Field Service Regulations,"
vol. ii. (1921)).
All classes of artillery are included in modern military operations.
Motor traction enables the heaviest guns to be brought to the
battlefield and to be removed when a commander decides to withdraw from
battle, while the increase in the defensive power of obstacles and
small arms fire, combined with the increase in mobility afforded by
motor traction, enables all but super-heavy artillery (which require a
railway mounting) to be placed close behind the infantry in Attack and
Defence. It is, however, obvious that the closest support can be given
by the guns that are weakest in shell-power, on account of the
superiority in mobility possessed by the lighter guns.
In Modern Warfare a great proportion of the work of artillery is
carried out, of necessity, in the hours of darkness, owing to the
frequency of movement by night to avoid aërial observation, and to the
consequent use of indirect artillery fire to inflict losses during such
movements. The artillery personnel therefore requires to be relieved
with greater frequency than in the days before the use of aircraft.
The growth of artillery during the war was symbolical of the continual
changes in the methods of warfare, its numbers and power increasing out
of all proportion to the experience of previous wars. "The 486 pieces
of light and medium artillery with which we took the field in August,
1914, were represented at the date of the Armistice by 6,437 guns and
howitzers of all natures, including pieces of the heaviest calibre"
(Sir D. Haig's Dispatches). "From the commencement of our offensive in
August, 1918, to the conclusion of the Armistice some 700,000 tons of
artillery ammunition were expended by the British Armies on the Western
Front. For the fortnight from August 21 to September 3, our daily
average expenditure exceeded {170} 11,000 tons, while for the three
days of the crucial battle on September 27, 28, and 29 (_Second Battle
of Cambrai_) nearly 65,000 tons of ammunition were fired by our
artillery" (Sir D. Haig's Dispatches).
In the Table of Artillery Ranges on p. 173, the effective ranges of
light artillery firing H.E. shell are based on the use of No. 106 fuse.
"The invention of a new fuse known as '106,' which was first used at
the _Battle of Arras_ (April 9-June 7, 1917), enabled wire
entanglements to be easily and quickly destroyed, and so modified our
methods of attacking organised positions. By bursting the shell the
instant it touched the ground, and before it had become buried, the
destructive effect of the explosion was greatly increased. It became
possible to cut wire with a far less expenditure of time and
ammunition, and the factor of surprise was given a larger part in
operations" (Sir D. Haig's Dispatches).
Artillery is classed under the designations Light, Medium, Heavy, and
Super-Heavy.
LIGHT GUNS.--_Pack Guns_, with a calibre of 2.75 inches, are weakest in
shell-power, but they possess a mobility greater than any other
artillery and can be moved in country which would present insuperable
obstacles to wheeled traffic. _Pack Howitzers_, with a calibre of 3.7
inches, are particularly valuable in close country, the high angle of
descent enabling the attack or defence to search the steepest cover.
_Horse Artillery Guns_, firing a 13-pound shell, are the most mobile of
all wheeled artillery and are normally employed with mounted troops.
All ranks of the Royal Horse Artillery are mounted, and its mobility is
scarcely less than that of cavalry. _Field Guns_, with a calibre of 3
inches, firing an 18-pound shell, are the principal artillery weapon of
a field army. Although inferior in mobility to Pack or Horse
Artillery, they have greater shell-power and afford the principal
support to infantry in closing with or repelling the enemy. Their
power to inflict casualties {171} by enfilade fire with shrapnel makes
them specially suitable in the defence, and the accuracy of modern
weapons enables them to co-operate in the Attack with covering fire,
under the protection of which infantry may advance unimpeded to the
assault. In addition to their normal functions, and to their
employment in counter-battery work, they can be employed in the
reduction of defences by bombardment with High Explosive shells, in
neutralising an area by the use of gas shells, or in providing
artificial cover by the production of _Smoke_. _Field Howitzers_, with
a calibre of 4.5 inches, have increased offensive power and practically
the same mobility as field guns.
Light guns are the principal weapons for protection against _Aircraft_
and for defence against _Tanks_. The Tank is powerless against
artillery, and its most effective enemy is light artillery. During the
_First Battle of the Somme_ a new terror was added to the British
attack by the introduction of the Tank, which surmounted inequalities
in the ground, crushed the wire defences, and crossed the trenches.
Although accompanied by infantry, it was regarded as an all-conquering
and decisive factor. At one period of the battle, however, a number of
Tanks were placed out of action by a single field gun, manned and fired
with the greatest gallantry by a single German artillery officer, who
fired point-blank at each Tank as it surmounted the crest of a rise.
Infantry were in close support, and a single Lewis-gun section could
have prevented the use of the field gun.
MEDIUM GUNS.--Medium guns, firing a 60-pound shell, are principally
employed in counter-battery work and in fulfilling the functions of
18-pound field guns at a greater range and with greater force. _Medium
Howitzers_ occupy the same relative position, their offensive power
being greater than that of the Field Howitzer.
{172}
HEAVY GUNS.--Heavy guns of 6-inch calibre, firing a shell of 100
pounds, are used against targets beyond the range of light and medium
guns, and with greater effect. _Heavy Howitzers_, of 8-inch or
9.2-inch calibre, are principally employed against covered batteries
and strong defences, or for destroying wire entanglements with
instantaneous fuses.
SUPER-HEAVY GUNS.--Super-heavy guns of a calibre of 9.2 inches and
upwards are usually carried on railway mountings, and while they
possess a high muzzle velocity, considerable shell-power, and a high
degree of mobility (which enables them to come into action in any part
of the battlefield where suitable rails have been laid), their arc of
fire is very restricted and their "life" is short. _Super-Heavy
Howitzers_, of 12-inch or 18-inch calibre, possess similar advantages
and disadvantages to super-heavy guns. Their normal use is the
destruction of permanent defences, the breaking down of bridges, etc.
The 12-inch weapon is also used on tractor-drawn mountings and is
highly effective in counter-battery work.
The table on p. 173 is based upon particulars given on p. 26 of "Field
Service Regulations," vol. ii. (1921).