One of the largest guns ever constructed, this was probably an experimental weapon. Ordered in 1938, the prototype gun and cradle were apparently fired a few times although the proof mounting was not completed. It seems unlikely that this weapon was ever intended to be used as an actual naval gun as even the gigantic H-44 battleship was to be armed with "only" 50.8 cm (20") guns.

Construction was of built up design consisting of four layers; a shrunk liner, A tube and two outer tube layers. Used a horizontal sliding breech block, similar to other Krupp designs.

Actual bore diameter was 53.34 cm (21.0").

This projectile is modeled in Nathan Okun's Facehard programs.

Gun Characteristics

Designation 53 cm/52 (21") Gerät 36
Ship Class Used On Experimental
Date Of Design 1938
Date In Service 1941 (?)
Gun Weight Including breech mechanism: 329.8 tons (335.1 mt)
Gun Length oa 1,090.55 in. (27.700 m)
Bore Length 1,025.2 in. (26.040 m)
Rifling Length 843.2 in. (21.417 m)
Number Of Grooves (110) 0.236 in deep x 0.323 in (6.0 mm x 8.2 mm)
Lands 0.277 in (7.03 mm)
Twist Increasing RH 1 in 35.9 to 1 in 29.9
Chamber Volume 76,280 in3 (1,250 dm3)
Rate Of Fire Probably less than 1 round per minute


Type Cartridge - Bag - Bag
Projectile Types and Weights APC L/4,9: 4,850 lbs. (2,200 kg)
HE L/4,9 nose fuze: 4,850 lbs. (2,200 kg)
Bursting Charge APC L/4,9: 100.2 lbs. (45.45 kg)
HE L/4,69 nose fuze: 485 lbs. (220 kg)
Projectile Length APC L/4,9: 103.2 in (262.1 cm)
HE L/4,9 nose fuze: 103.8 in (264.6 cm)
Propellant Charge 1 Fore: 551 lbs. (250 kg) Gu RP 2
Middle: 551 lbs. (250 kg) Gu RP
Main: 661 lbs. (300 kg) Gu RP
Brass case for main charge: 346 lbs. (157 kg)
Muzzle Velocity 2,690 fps (820 mps)
Working Pressure 19.0 tons/in2 (3,000 kg/cm2)
Approximate Barrel Life N/A
Ammunition stowage per gun N/A
  • ^These guns used a three part charge with the fore and middle charges being identical. The rear or main charge was in a brass cartridge case, similar to those used for other German naval guns.
  • ^Gu RP was a nitroguanidine propellant in hollow tubular form.


Range with 4,850 lbs. (2,200 kg) AP
Elevation Distance
50 degrees about 51,950 yards (47,500 m)


Data from:

  • "Naval Weapons of World War Two" by John Campbell

Page History

21 March 2007
19 May 2012
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