self-propelled artillery piece (SP),
marrying the fire-power of the field
gun to the mobility of the tank, first
appeared during the Great War and
was developed further during the inter-war
years. The Germans used their Sturmgeschutz
("assault gun") for direct
infantry support early in the Second
World War, but then realised the value
of the mobile gun in an anti-tank
role and discontinued production of
the Sturmgeschutz in favour
of various models of Panzerjäger
("tank destroyer"). One
might well ask why more tanks were
not simply produced, considering that
the German tanks were able to mount
guns, in the Panthers and Tigers at
least, which were more than capable
of destroying the best tanks the Allies
had by the time of the Normandy campaign.
A key factor was the relative expense
of the tank as compared to the SP,
which, lacking a fully-traversing
turret, could be manufactured more
cheaply and in larger numbers.
As for the British Army, the SP remained
first and foremost a field artillery
piece. Royal Artillery doctrine since
the First World War was governed by
adherence to the principle of concentration
of fire-power. Any suggestion of decentralization
of control of the guns into 'penny
packets' was stubbornly attacked.
To use SPs in the manner of the Sturmgeschutz
would have meant apportioning small
numbers of guns to forward units,
and depriving the Royal Artillery
of its devastating ability to bring
large numbers of guns to bear on a
single target in a short time.
The British SP field gun was not designed
for firing on the move and was not
armed with machine-guns, so it could
not defend itself against enemy infantry.
It was thought that a suitable role
would be to engage tanks that stood
off and neutralized forward localities.
SPs like the Sexton 25-pounder were
therefore never expected to provide
direct fire-support to tanks on the
leading edge of an assault. They were
used in the Canadian and British armies
as conventional towed pieces, deployed
in indirect fire positions well behind
the tanks. Gunners providing indirect
support could not see the target,
but had their fire corrected by a
Forward Observation Officer (FOO).
SP guns of the 8th Field
Regiment, R.C.A., firing
21 gun salute to celebrate
VE Day, Groningen, Netherlands,
8 May 1945.
by Jack H. Smith. Department
of National Defence / National
Archives of Canada, PA-114372.
25-pounder self-propelled gun
The Sexton had a crew of six, protected
by armour of up to 38 mm in front, although
the top was open. It weighed about 24,400
kg, and carried 112 rounds of ammunition.
2150 Sextons had been built by 1945,
when production ceased, and the Sexton
continued in service until the late
Entering service in September
1943, the Sexton SP mounted the 25-pounder
gun on the Canadian Ram chassis and
was built at the Montreal Locomotive
Works. The Sexton was driven from
the right-hand position, as were all
vehicles produced for the British
and Canadian armies. A number of gun
modifications had to be made to fit
the 25-pdr to the Sexton, such as
limiting of the recoil system so that
the gun could be properly elevated.
Sextons were widely used within 21st
Army Group during the campaign in
Northwest Europe after July 1944 when
the 25-pdr replaced the American 105
mm SP, called the "Priest".
The conversion to Sextons rendered
the 2nd Canadian Corps' Priests superfluous,
and the latter were modified to be
used as Kangaroos during Operation
Totalize, 7-10 August 1944, in what
was the first practical use of the
armoured personnel carrier in combat.