Tag Archive for 'railway gun'

28 cm K5 (E): Railway Gun

28 cm K5 (E): Railway Gun

The German 28 cm K5 (E) has an unconfirmed range of 31 miles and fires a pre-engraved projectile weighing approximately 550 pounds. It is fired from a turntable affording a 360° traverse.

The gun has a 70-foot 8-inch barrel held in a sleeve-type cradle. The barrel recoil mechanism, fitted between two arms projecting downward from the cradle, consists of two hydropneumatic cylinders and a single hydraulic buffer cylinder. The cradle is supported by trunnions which rest in bearings on top of a box-like frame, of girder construction, which in turn is supported on two pintles resting in bearings in the center of two 12-wheel trucks. The front pintle bearing rides in a rail on the front truck and can be positioned six inches either side of center, thereby allowing a car traverse of approximately 1°.

The equipment in effect has a double recoil action. Besides the barrel recoil which is approximately 32 inches, the gun car recoils. It is coupled to the front of the turntable platform by a hydraulic buffer and a hydropneumatic counterrecoil mechanism which returns the car to battery position.

A turntable platform is transported as part of the equipment and in transport forms a flat car with a 103-foot bed resting on two 8-wheel trucks.

A central jack helps support the tremendous weight of the gun and carriage which amounts to around 230 tons and also serves as a central pivot for the turntable.

The powder chamber is approximately 10 feet 5 inches long. Obturation is obtained by means of a short brass cartridge case and the breech is closed with a horizontal sliding type of breechblock. Firing is of the percussion type.


Caliber      280 mm (11 ins.)
Length of barrel 70 ft., 8 ins.
Length of tube 67 ft., 5 ins.
Length of rifling 57 ft.
Rifling Right Hand uniform twist
Weight of barrel (Leopold)* 187,880 lb.
Length of car 95 ft., 7 ins.
Length of carriage 69 ft., 8 ins.
Width of carriage (overall) 8 ft., 8 1/2 ins.
Number of grooves 12
Width of grooves 5/8 in.
Depth of grooves 17/64 in.
Max. range 54,680 yds.**
Traverse on turntable 360°
Carriage traverse (approx.) 1/2° R; 1/2°
Elevation (estimated) 50°
Ammunition Separate loading—steel splined projectile
Weight of projectile (approx.) 550 lb.

*Two of these guns were found in Italy; one was called “Leopold,” and the other “Robert.” The weight of the barrel on the latter model is 187,165 pounds.
**Not verified.

German: p. 100.2

20 cm K. (E): Railway Gun


Batteries of these railway guns in concrete emplacements were found on both the Cherbourg and Brest Peninsulas in France. Equipment consisted of the gun, carriage, turntable, power plant and electrical operating unit, and ammunition car.

The piece is of the built-up type, consisting of a tube and two jackets. It is screwed into the breech ring. The breechblock is of the horizontal sliding wedge type. The hydropneumatic recoil system has two cylinders located under the carriage; the pistons are fastened to the lower end of the breech ring.

The carriage, when mounted on a turntable, has a traverse of 360 degrees; it is estimated that elevation is from 0 to 840 mils.The turntable, consisting of two sections bolted together, rotates on a central pivot and a portable circular track. Four wheels at each end of the turntable support it on the track. Electric motors are geared through these wheels to rotate the piece in azimuth. It is very similar to the 28 cm K. 5 (E) reported on page 100.2.

A small ammunition car, equipped with a removable roof, is mounted on trucks and runs on a two-rail track which is built in as a part of the turntable track.


Weight of gun       45,500 lbs.
Weight of carriage w/ gun 189,000 lbs.
Caliber 203 mm (7.982 ins.)
Weight (firing position) 92.5 tons
Length (traveling position) 63 ft. (approx.)
Height (traveling position) 13 ft.
Height (firing position)
Width (overall) 13 ft. (approx.)
Track Std. railway gage 56 1/2 ins.
Length of tube 30 ft., 7 ins.
Length of tube and breech 32 ft., 8 1/2 ins.
Length of rifling 22 ft.
Rifling Uniform R.H. twist
No. of grooves 64
Width of grooves 0.188 in. (approx.)
Depth of grooves .125 in. (approx.)
Width of lands
Muzzle velocity (shell) 2,800 f/s
Range (est.) 36,000 yds.
Traverse (on turntable) 360°
Elevation (estimated) 47°
Length of recoil (from recoil index slide) 25 1/2 ins.
Ammunition APCBC, APBC, HE, Practice, Illuminating with parachute
Wt. of projectile 259 lbs.
Wt. of propellant (max. charge) 96.5 lbs.

German: p. 102.1 (May 1, 1945)