15 cm s. I. G. 33: Heavy Infantry Howitzer

The 15 cm s. I. G. 33 (schweres Infanterie Geschütz 33) is a standard German infantry support weapon that may be used for either high- or low-trajectory firing. Both high-explosive and smoke shells are used with the gun.

The breech mechanism is of the usual German design, a horizontal sliding block opening to the right. A trough-shaped cradle is provided with guide ways in which guides on the gun move during recoil. On either side, at the front of the cradle, is a pad to receive the unabsorbed force of run out. Between the pads is the expansion chamber which receives the buffer fluid forced from the buffer by expansion as it becomes heated. Both the buffer and recuperator are housed in a casing underneath the barrel. The recoil system differs from that of most German artillery in that the expansion chamber of the buffer is outside the buffer itself, connected to it by a pipe; and no cooling cylinder is provided.

Toward the rear are the two small cradle arms to which the trunnions are fixed. Each trunnion is provided with a cranked compensator lever which compresses the equilibrator spring. The elevating arc is secured underneath and the recoil indicator at the right rear. When traveling, the cradle is secured to the carriage by a clamp which is operated by a lever secured to the clamp shaft.

The box-type carriage is fitted with a fixed spade and a detachable sand spade. Spring equilibrators situated one on either side of the carriage neutralize muzzle preponderance at all angles of elevation. The elevating gear, consisting of a worm gear, rack, pinion, and shaft, is operated from the right of the carriage; the traversing gear is operated from the left side by a system of gear wheels and shafting. A standard German Zieleinrichtung 34 is used for sighting.

SPECIFICATIONS

*There are six zones of propellant. The maximum is obtained in Zone 6.

German: p. 104