Spigot Mortar or "Blacker Bombard" was invented by Lieutenant-Colonel
Blacker with the aim of providing cheap and easily produced weapons after most
of the British Armys heavy equipment had been lost at Dunkirk.
as a spigot this design differs from more conventional efforts by dispensing completely
with a barrel of any kind, instead using a projectile with a hollow tail unit.
This hollow tail contained a percussion charge, which is detonated by the impact
of a steel rod, which is driven into the tail |
The explosion of the charge
propels the mortar towards its target
mortar is supported on a simple steel pin or a tripod.
In its static defence role, the mortar was
mounted on a steel pin set into a substantial base of reinforced concrete. This
was in turn set:-
ground level protected by concrete re-inforced side walls.
to the plinth by the wall on the left, are the remains of two ammunition alcoves
side by side.
(b) a camouflaged
weapons pit to offer some protection to the three man gun crew.
(see B &
W picture above)
weapon fired a 20lb fin-stabilized anti-tank bomb warhead containing a high explosive
charge using black powder as a propellant. The weapon had the drawback of when
the warhead hit its target, the fins had a nasty habit of flying backwards along
the original trajectory with the resulting danger of injury to the firing crew.
The "Bombard" had an effective range with the anti-tank bomb of around
100-150 yards, so the firing crew was expected to wait until any tanks were at
close range. It was also capable of firing a 14 lb anti-personnel bomb with a
maximum range of around 500 yards. They were fairly accurate and effective at
short range. A portable mount was also available, but weighed around 350lb and
took 3 men to move it.
A large spring was cocked
by unlatching the shoulder pad, standing on it, and pulling the weapon up so that
the spigot and spring were latched in the firing position. This was only done
for the first cocking before firing. The body was then slid back to the shoulder
pad and latched.
A bomb was then placed in the tray at the front of
the weapon and it was ready to fire. On pulling the trigger the spigot was released
from the spring. It entered the rear of the bomb where it ignited an explosive
charge, which propelled the bomb along the spigot and out of the weapon. The same
explosion repelled the spigot back into the spring re-cocking the weapon. All
that was needed was another bomb added to the tray.
weapon was rejected by the regular army but saw service with Home Guard and airfield
protection units from 1941-1944. It was very effective against tanks, if you had
the nerve waiting for them to be within the 100yd firing range.