The operation of this rocket is very similar to that of the 28 cm Wurfkörper. It is fired from the crate, either metal or wood.
This rocket is stabilized by rotation due to the angle of the jets, of which there are 26 inclined at an angle of 14°. The internal throat diameter of the jets is 5.5 mm.
The motor tube is a solid forging, machined inside and out and threaded externally at both ends. The closed end screws into the bomb section; the open end receives the venturi block.
The propellant charge consists of a single multiperforated stick. It is supported at the venturi end on a flat grid held to the venturi block by means of a bolt. The grid consists of a ring 3/16 inch thick, 4 3/8 inches in external diameter, and 3 1/8 inch in internal diameter supported by six small cylindrical spacers 1/2 inch in diameter and 3/8 inch high from a flat plate 1/10 inch thick and 4 3/8 inches in diameter. The free space at the closed end of the 4 3/8 inches in diameter.
The ignition system consists of an electrical igniter inserted in place of the screw in the bolt in the center of the venturi block. Behind the igniter lies a bag of rough cloth containing 10 grams of the primary igniter composition in the form of six-pointed star-shaped flakes. A maintainer composed of compressed pellets in an aluminum container is situated at the closed end of the tube and acts as an igniter composition. The rapid transmission of the flash between these two is effected by the lengths of inflammable tubing housed in the conduits of the charge. The one in the center conduit is quickmatch; the tube is closed at each end by a gunpowder pellet.
A thin sheet of aluminum acts as a sealer at the venturi end. This does not appear to be sufficient to prevent the entrance of moisture. The bomb head contains 11 gallons of oil and a point-detonating fuze.
SPECIFICATIONS
| Weight (total) | 174 lb. (approx.) | |
| Weight of motor tube | 23 lb., 14 oz. | |
| Weight of motor tube (filled) | 49 lb., 8 oz. | |
| Weight of venturi block and bolt | 9 lb., 6 oz. | |
| Weight of propellant charge | 14 lb., 7 oz. | |
| Weight of grid | 1 lb., 1 oz. | |
| Length (total) | 5.08 ft. | |
| Length (body) | 3.3 ft. | |
| Length of motor tube (overall) | 18 5/8 ins. | |
| Diameter of bomb | 32 cm | |
| Diameter of motor tube (external) | 5 1/2 ins. | |
| Diameter of motor tube (internal) | 5 ins. | |
| Depth of motor tube (internal) | 18 ins. | |
| Range (maximum) at 42° | 2,217 yds. (approx.) |
German: p.353