Sturmmörser: 38 cm Rocket Projector on Tiger E Chassis

This equipment consists of a 38 cm rocket projector (Raketen Werfer 61) mounted on a modified Model E Tiger I chassis (see p. 38). A heavy rectangular superstructure of the type used on the German self-propelled guns replaces the normal superstructure and turret of the Model E. The rocket projector is mounted in the front plate of the superstructure, offset to the right of center. The superstructure is made of rolled armor plates and is of welded construction with the side plates interlocked with the front and rear plates. A heavy strip of armor is used to reinforce the joint between the front plate and glacis plate on the outside. Armor thickness varies from 40 mm to 150 mm.

The main armament, which fires a splined projectile 58.6 inches long (see page 354.2), differs radically in design and construction from any weapon previously examined. The barrel consists of a cast outer jacket, and a spaced liner of 1/2-inch steel. The latter, which is 74 1/4 inches long, is rifled, having nine grooves with right hand twist, one turn in 17.6 calibers. At the extreme rear, the grooves widen to aid in positioning splines near the base of the projectile. The liner is held in place by four steel blocks at the rear, and a perforated ring at the muzzle end. This ring has 31 equally spaced holes around its face. The breech mechanism is a horizontal sliding plate 2-5/16 inches thick opening from left to right.

The propellant gases are deflected between the tube and liner by an unusual obturator, and escape through a perforated ring at the muzzle. The metal obturator comprising a thin “L” shaped outer ring, a heavier “L” shaped perforated inner ring, and a spacer ring, fits into a circular recess in the front face of the breech plate. When the projectile is fired, the propellant gases pass through the ports to the chamber between the inner and outer rings. The face of the outer ring is forced against the rear face of the tube, and the sides against the recess in the breech plate, thereby obtaining the gas seal.

SPECIFICATIONS

(VEHICLE)
Weight (in action) (estimated)		68 tons
Length (overall)		20 ft., 8 1/2 ins.
Width (overall)		12 ft., 3 ins.
Height (overall including stowage crane)		11 ft., 4 ins.
Height (overall less stowage crane)		9 ft., 3 ins.
Ground clearance		17 ins.
Tread centers		9 ft., 3 1/2 ins.
Ground contact		12 ft., 6 ins.
Width of track		28 1/2 ins.—20 1/2 ins.
Pitch of track		5 1/8 ins.
Track links		96
Fording depth		70 ins.
Theoretical radius of action
Roads		87 miles
Cross-country		53 miles
Speed
Roads		25 miles
Cross-country		15 miles
Superstructure Armor
Front plate		150 mm at 45° to vertical
Projector mantlet (average)		69 mm rounded
Projector shield (average)		150 mm rounded
Side plates		84 mm at 20° to vertical
Rear plate		84 mm at 10° to vertical
Top plate		40 mm
Spherical cradle		100 mm rounded
Ammunition (Rds.)		12
Engine		Maybach HL 210, V-12, 630 hp.
Transmission		Preselector, hydraulic—8 speeds forward, 4 reverse
Steering		Controlled differential, hydraulic
Crew (unconfirmed)		7
(PROJECTOR)
Caliber		380 mm (14.96 ins.)
Length of tube		81 1/8 ins.
Length of liner		74 1/4 ins.
Thickness of liner		1/2″
No. of grooves		9
Width of grooves		0.4 in.
Width of grooves at rear		1.06 in.
Depth of grooves		0.2 in.
Twist of grooves		Right hand, one turn in 17.6 caliber
Max. range (horizontal)		6,179 yds.
Firing mechanism		Continuous-pull
Traverse		20°
Elevation (approx.)		85°
Depression (approx.)		0°
Ammunition		H.E. (R. Sprenggranate 4581)
		HEAT (R. Hollandungsgranat 4592)
Wt. of projectile*		761 lbs.

*Weight zones are marked to the nearest 5 kg. (12 lbs.)

German: p. 38.3-38.4 (June 1, 1945)