Submarines and their Weapons - Aircraft of World War II

21CM KANONE 12 (K12)
Calibre: 21.1cm (8.3in)
Barrel length: 33.34m (109.38ft)
Weight (overall): 309,000kg (681,215lb)
Weight of shell: 107.5kg (237lb)
Range: 115km (71.5 miles)
meant that it distorted under its own weight and had
to be very carefully braced. It also needed its trunnions
to be very accurately located at the centre of
balance, otherwise elevation would have been very
difficult. The mount was in the form of an over-size
railway car (more accurately, two railways cars); the
main structure, with the trunnipn supports and elevating
machinery, was mounted on two sub-frames each
of which, in turn, was mounted on a pair of bogies,
two eight-wheeled units to the fore and two tenwheeled
units behind. For operational purposes it ran
on a track section laid in an arc, and it was trained by
running it backwards and forwards. The whole
ensemble weighed 304.8 tonnes (300 tons) and was
over 41m (135ft) long. It appears that the two guns
were operational, with Eisenbahn Batterie 701, only
for brief periods in late 1940 until early 1941, and
they were directed at targets in Kent, particularly
around Dover, from emplacements in the Pas de
Calais. The greatest range attained seems to have
been of the order of 90km (56 miles). One example
was captured by Allied forces in Holland in 1945.
THE HIGH-PRESSURE PUMP
The K12 guns were not the only weapon developed
with an eye to bombarding southern England with
artillery fire, but the other project, the so-called
'High-pressure Pump', was much less conventional,
and relied on a principle first demonstrated, albeit
imperfectly, in the United States of America around
1885. It was the work of Lyman and Haskell, who reasoned
that subsidiary propellant charges, spaced at
intervals up the barrel of a gun in side-chambers and
ARTILLERY
Above: The 21cm K12 railway gun had the longest range
of alf the 'superguns'- around 115km (71.5 miles),
depending on weather conditions.
ignited a micro-instant after a shell had travelled past
on its way up the barrel, would provide a subsidiary
propellant force and thus increase the muzzle velocity
of the projectile. The result, when they built it on
the instructions of the US Army's Chief of Ordnance,
didn't much resemble an artillery piece as we know it.
Firstly, the barrel had to be so long that it could not be
supported save on the ground and had to be laid on an
inclined ramp; and secondly, it had pairs of chambers,
angled back at 45 degrees, let into it for much of its
length. In the event, it didn't work: obturation was
faulty, the flash from the original propellant charge
bypassed the shell and ignited the subsidiary charges
ahead of it, defeating the whole object of the exercise.
Lyman and Haskell gave up, and the idea was consigned
to the history books. It was apparently raised
again in Britian, during World War I, but was turned
down once more.
In 1943, a German engineer named Cönders, who
worked for Röchling Eisen- und Stahlwerke (which
was not just a producer of iron and steel, but had also
been active in the field of munitions) proposed an
identical weapon. Thanks to the success of one of
Cönders' other projects, the so-called 'Röchling
Shell' (a bunker-buster par excellence), those who had
the all-important ear of the Führer, particularly Albert
Speer, the Minister of Munitions, took note. Even
though he would only proceed on the understanding
that no one, not even the HWA, 'interfered' with his
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