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21cm Kanone Eisenbahn - Railway Gun

21cm KE21cm Kanone 12 V Eisenbahn
Specification :

Calibre :

211mm ( 8.31" )

Length of Gun : 33300mm ( 109.25 ft )
Caliber : 158
Barrel weight (kg) : 99,708
Elevation : +25° to +55°
Axle : 2 x 5 and 2 x 4
Weight in action (kg) : 302,000
Maximum Range : 45,000m
21cm K12 KE Photo Gallery
21cm K12 The 21cm Paris Geschütz (Paris Gun) of 1918 had been developed by Krupp at the request of the German navy, and it was manned and controlled during its short but spectacular life by naval personnel. During the remainder of the 1920s and early 1930s a great deal of theoretical research work was done, and the Vögele Drehscheibe (Portable turntable) was designed and perfected.

Eventually, with all the paperwork done and the political indications favourable, work begin on the actual gun. The great problem was to achieve the very high velocity that would put the shell into the stratosphere, there allowing it to travel against much less air resistance and so attain a very long range, the same technique that had been employed with the Paris gun. The 1918 weapon had, however, worn out at an incredible rate, to such a degree that shells of gradually increasing diameter, serially numbered, had to be made to suit the rate of wear.

The relatively simple box girder structure carried on two sub frames which were in turn mounted on double bogies, the front sub frame on two ten-wheel and the rear on two eight-wheeled  bogies. 

To absorb the recoil the gun was mounted in a ring cradle with a hydro pneumatic recoil system and the mounting incorporated two more hydro pneumatic systems connected to the two sub frames, so that the entire girder section was capable of recoiling some 980mm (38.58") rearwards across the sub frames. Provision was made to disconnect the gun from its recoil system and pull the barrel back some 1500mm in the cradle, reducing the overall length and improving the weight distribution, so that when traveling the entire equipment was manoeuverable within the standard loading gauge and track curvature.

The gun itself posed one or two problems. It was exceptionally long (33.3m/1089.25 ft) and required to be braced throughout its length to prevent it bending under its own weight. It was moreover considered impossible to balance such a preponderance and so the trunnions were set forward to obtain as much weight as possible at the breech.

This in turn meant that the breech came perilously close to the track when the gun was elevated, and so it became necessary to design and install a hydraulic jacking system to lift the whole mounting structure from the subframe by 1.00 m (3.28 ft) before firing; this allowed the breech room to recoil. The jacking process had to be repeated for every round, as it was impossible to load the gun when the mounting was raised.

This weapon, completed in 1938 and issued to the army in March 1939, was known as the 21cm K 12V. It was a success, but the complicated business jacking it up and down between shots was not well received by the army and the designers embarked on a major redesign. Much research was done into the question of balancing the immerse barrel length, until it was found that hydro pneumatic balancing presses could be made to work at much greater weights and pressures than had previously been believed possible.
The mounting was consequently redesigned with the barrel as far forward as possible and with a single hydro pneumatic balancing press. The whole equipment was also made slightly longer, and the recoil stroke of the gun mounting was increased to 1500mm (59.06 ")

Courtesy from
German Artillery of World War II - Ian V.Hogg - Greenhill Books - ISBN 0887403220 more..
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21cm K12 V in action
Front view of the gun being moved into firing position.
Note also the heavy cast connecting link that attached the gun carriage to the buffer system of the Vögele turntable.
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21cm K12 V
The hydraulic jacks, shown here under the ends of the gun carriage
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21cm K12 V in action
The massive, heavy breech, here with the breechblock closed, served as a counterweight to the extremely long barrel. The great weight of the breech assembly allowed the trunnions to be mounted near the rear of the barrel, resulting in high permissible angles of fire and a lower of center of gravity.
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21cm K12 V in action
21cm K12 V in travel order
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The artilleryman on the carriage adjusts the firing mechanism prior to the command to fire, while another crew member checks the breech.
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References / Credits :
Deutsche Eisenbahn Geschützen -
Gerhard Taube - Motor Buch Verlag - ISBN 3-613-01352-5 more..
Die schweren Geschütze der Welt - Franz Kosar - Motor Buch Verlag - ISBN 3-613-02204-4 more..
German Artillery of World War II - Ian V.Hogg - Greenhill Books - ISBN 0887403220 more..
Eisenbahn Geschütze der Welt - Franz Kosar - Motor Buch Verlag - ISBN 3-613-01976-0 more..
German Railroad Guns in action - Joachim Engelmann - Squadron - ISBN 0-89747-048-6 more..



© one35th - Last updated on  :  Sunday, April 20, 2008