Tag Archive for '21cm'

21 cm Mrs. mit Mrs. Laf. 18: Heavy Howitzer

21 cm Morserlafette 18 Heavy Howitzer

The 21 cm Morserlafette 18 is the standard heavy howitzer in use by German troops. The piece comprises a loose barrel, half jacket, and breech ring. A lug on the collar of the barrel secures it to the breech ring; ring and jacket are fastened together by a key which fits into a key way in the latter. The ring, jacket, and barrel are clamped together by a securing ring at the front of the jacket.

During recoil, the piece is supported by a pair of rollers below the jacket and another pair under the rear of the breech ring. A bracket at the top of the breech ring receives the piston rod, and a lug on its lower face receives the buffer piston rod.

The breechblock is of the horizontal sliding block type. On the rear face of the breech ring is a lever which operates (a) a plunger in a vertical boring in the bottom of the breech opening, and (b) a catch engaging a slot in the buffer nut interlocking the breech mechanism.

The carriage is interchangeable with that of the 17 cm K. mit Mrs. Laf. 18, with the exception of the following points: the safety limit of recoil of the upper mounting is 58.27 inches, whereas in the case of the 17 cm K. mit Mrs. Laf. 18 it is 56.30 inches; and the air pressure in the compensators is 464 lb./sq. in. against 626 lb./sq. in. in the case of the 17 cm K. The latest model of the 21 cm and 17 cm Mrs. Laf. 18 carriage is equipped with a pivot platform attached to a supporting frame situated near the center of the lower carriage body, which allows complete and continuous 360° traverse.


Caliber         21 cm (8.27 ins.)
Weight of gun in action 18.5 tons
Weight of piece 5.79 tons
Length of howitzer (travelling) 41 ft., 2 ins.
Length of bore 17 ft., 3 ins.
Length of chamber 25.31 ins.
Number of grooves 64
Rate of fire 1 rd./min.
Muzzle velocity 1,854 f/s
Range (maximum) 18,263 yds.
Elevation 70°
Traverse 16° (360° with the pivot platform)
Ammunition High-explosive (wt. 249 lbs.)
  Anti-concrete shell (wt. 268 lbs.)

German: p. 101

21 cm K. 39: Heavy Field Gun

Skoda 21 cm K. 39: Heavy Field Gun

The 21 cm heavy field gun (K. 39), an original Skoda design, was taken over by the German Army shortly after the invasion of Czechoslovakia. For transport, the equipment may be broken down into three loads, each of which is mounted on two 2-wheeled, pneumatic-tired bogies.

The piece consists of an autofrettaged monobloc barrel and loose liner, and a breech ring. The breechblock is of the interrupted screw threaded type, incorporating an obturator pad, obturator spindle and percussion firing lock. On recoil, the piece slides in a cylindrical sleeve in the cradle.

The upper carriage is fitted to a turntable which revolves on a ball race mounted in the platform. The platform consists of a rectangular sheet steel box which is dug into the ground. Four removable arms located at the corners of the platform support it by bearing on the ground by means of special feet. During transport, the arms are lowered and serve to support the platform on its bogies.

The traversing and elevating mechanisms, each with two-speed gearing, are operated from handwheels on the left of the carriage.

Four types of ammunition are used in the gun: the original Czech high explosive shell; a German version of the same shell with the base fuze omitted; an anti-concrete shell with ballistic cap and base fuze; and an armor-piercing shell with base fuze. It is loaded at 8° elevation with the help of a special 2-wheeled shell trolley.

There are two other versions of the weapon, the K. 39/40 and the 39/41. Although the two later models are modifications of the original Skoda design, they do not differ in main performance details


Caliber      210 mm (8.27 ins.)
Weight (traveling position) Three loads approx. 16 1/2 tons each
Weight (firing position) 37.2 tons
Length of barrel including breech ring 31.3 ft.
Muzzle velocity (max.) 2,625 f/s
Max. range (horizontal) 32,800 yds.
Traverse 360°
Wt. of max. charge 82.8 lbs.
Elevation 45°
Depression -4°
Ammunition H.E.; Anti-concrete; A.P.
Wt. of projectile All 298 lbs.

German: p. 100.3 (May 1, 1945)