the V3
super gun
V-3 Gun
The V3 was
not a missile project but a massive cannon, also known as
the "London gun" and "V-3 cannon". It was designed to lob
shells from it site on the coast of France across the
English Channel and hit London.
The V-3
Hochdruckpumpe (aka HDP, 'Fleissiges Lieschen'; 'Tausend
Fussler') was a supergun designed by Saar Roechling during
World War II. The 140 m long cannon was capable of
delivering a 140 kg shell over a 165 km range. Construction
began of a bunker for the cannons in September 1943 at
Mimoyecques, France. The site was damaged by Allied bombing
before it could be put into operation and was finally
occupied by the British at the end of August 1944. Two
short-length (45 m long) V-3's were built at Antwerp and
Luxembourg in support of the Ardennes offensive in December
1944. These were found to be unreliable and only a few shots
were fired without known effect.
V3 prototype
The V-3 used
Baron von Pirquet's concept of sequentially electrically
activated angled side chambers to provide additional
acceleration of the shell during its passage up the barrel
of the gun. This allowed a muzzle velocity of over 1500 m/s.
The projectiles of the smooth bore weapon used fins for
stability, as would be the case with the Canadian Martlet
series 25 years later.
Lyman and Haskell of the US Army had built an unsuccessful
prototype of the concept in the 1880's. It was found that
the expanding gases of the base charge moved well ahead of
the shell and ignited the auxiliary charges before the shell
passed them, actually slowing the shell down. But in 1941 an
engineer Conders at Saar Roechling proposed the use of
electrically-activated charges to eliminate the problem. A
20mm prototype was built at a test site at Misdroy (Miedzyzdroje),
Poland and successfully demonstrated in April-May 1943.
Hitler was persuaded that this could be a third terror
weapon to supplement the V-1 and V-2. Overruling the German
military, he ordered fifty of the guns to be built in
concrete bunkers in France in order to bombard London. The
first installation of five guns was to be built 165 km from
London at Mimoyecques, near Calais, under Operation Wiese.
The superguns were built at a fixed angle into a 30 m chalk
hill, covered by a 5.2 m thick protective concrete dome.
Each 140 m long cannon was capable of delivering a 150 mm /
140 kg shell on London.
The angled lateral combustion chambers were spaced every
3.65 m along the bore. The modular weapon could have the
lateral chamber sections replaced as they wore out (they
would burst after only a few firings).
Hundreds of slave workers began construction in September
1943 by sinking an initial tunnel 30 m below the hill's
surface into the chalk. French Resistance informed the
Allies of the new effort almost immediately. Bombing raids
to destroy the site began two months later. However the
bunker proved impervious to Allied bombs, even 5400 kg
Tallboy penetrator weapons. The weapons were nearing
completion when, on 6 July 1944, three Tallboys happened to
make it though the gun shaft openings. They penetrated 30 m
to the first level of the complex and exploded, killing
dozens of workers. Work on the complex stopped at this
point.
The Allies were unaware of this success and searched for new
methods to destroy Mimoyecques and other German bunker
sites. Under Project Aphrodite (USAAF) and Operation Anvil (USN)
radio-controlled, television-guided B-17 or PB4Y (B-24)
bombers crammed with ten tonnes of explosives were to be
flown by a crew near to the target. The pilot and co-pilot
would then bail out while an accompanying aircraft guided
the missile to a precision strike. This approach was
abandoned in August 1944 after a total lack of success and
several crew fatalities (including Joseph P Kennedy, Jr,
elder brother of the future president).
By the end of August the Germans completely abandoned the
complex in the face of the advancing British forces. Two
short-length (45 m long) V-3's were built at Antwerp and
Luxembourg in support of the Ardennes offensive in December
1944. These were found to be unreliable and only a few shots
were fired without known effect.
performance
to a: 85 km altitude suborbital trajectory. Standard warhead
mass: 140 kg. Maximum range: 165 km.
Destruction
Fortunately, the base at Mimoyecques met its destruction in
6 July 1944 at the hands of the Royal Air Force's 617
Squadron - better known as The Dam Busters - before the
Nazis could fire their first shot. The Dam Busters dropped
several 5 ton (5.4 tonne) Tallboy bombs (designed by British
inventor, Barnes Wallis) to destroy the V3 complex. One
Tallboy ripped a corner off the 20-foot thick concrete roof
and completely blocked one of the gun shafts. A near miss
collapsed another shaft and made the third shaft unfit to
use. Five hundred feet down, when the bombers came, 300
Germans and collaborators tried to shelter in what they
thought was complete safety. They are still there, entombed. |