Tag Archive for 'wurfgranate'

28 cm Wurfkörper Spr.: 28 cm Rocket Projectile

28 cm Wurfkörper Spr.: 28 cm Rocket Projectile

This package-type rocket is a self-contained unit fired from a metal or wood crate. Firing is accomplished by “pointing” the crate at the target, resting the front part of the crate on a mound of dirt (or a similar rest) at an angle from 5° to 45°, and firing by means of a hand electrical firing system.

The propellant charge, contained in the motor tube, is in the form of one stick weighing 14 lb., 9 oz. with one central hole and eight annular holes.

Eight grooves are formed in the sides of the propellant stick, and celluloid tubes are fitted into these grooves. A length of quickmatch in the central hole is inclosed in a celluloid tube.

There are two igniters, one at the front and one at the rear of the propellant. The rear igniter consists of a cloth bag containing 10 grams (154 grains) of NC powder. The front igniter is a metal holder containing a flash composition with a layer of initiating composition.

The bursting charge is contained in the large section, directly forward of the rocket motor tube.

The booster, known as Zdlg. 36, consists of a cylindrical aluminum container filled with penthrite wax and perforated at the top to house a thimble-shaped detonator.

The fuze, Wgr. Z. 50, is a point-detonating or graze action type. The safety pin is removed before firing, leaving the two centrifugal bolts and a split ring to act as a safety feature in flight. The detonator is situated in the inertia pellet.

There are 26 jets at the end of the motor tube inclined approximately 12° right, giving it rotation in flight for stability. The internal diameter of the jets is 0.5 cm (.19 in.) and the external diameter 1 cm (.38 in.).

SPECIFICATIONS

Weight (total)         181 lb.
Length (overall) 3 ft., 11 ins.
Length (body) 2 ft., 4 1/2 ins.
Length (tail) 1.85 ft.
Diameter (body) 11 ins.
Diameter (tail) .59 in.
Number of ports 26
Contents 110 lb. TNT
Range (maximum) at 42° 2,337 yds. (estimated)

German: p. 354

32 cm Wurfkörper M. Fl. 50: 32 cm Rocket Projectile (Incendiary)

32 cm Wurfkörper M. Fl. 50: 32 cm Rocket Projectile (Incendiary)

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

15 cm Wurfgranat 41: 15 cm Rocket Projectile

15 cm Wurfgranat 41: 15 cm Rocket Projectile

This rocket is fired from the German 6-tube Nebelwerfer 41. It resembles an elongated shell with a bulbous ballistic cap. The propellant is contained in the forward part of the projectile and the filling in the rear behind the ring which houses the jets. The propellant powder burns from both ends, giving faster and more even burning. The nozzles are arranged around a projecting annular jet unit about two-thirds of the distance from the nose. The jets are set at an angle to give the projectile rotation in flight, thereby eliminating the use of fins.

A complete round of this rocket projectile is composed of the following components (refer to photograph above): (i) pressed metal ballistic cap, which is screwed onto the projectile; (j) a motor tube; (d) an aluminum disk containing a black powder igniter charge; (a) a pressed metal spacer upon which the sticks of powder rest; (e) seven sticks of uniperforated stick powder; (b) a cellulose igniter tube containing black powder; (c) a cast-iron trap, which is placed over the powder at the rear end of the motor tube; (f) a black powder igniter charge, which is placed over the cast-iron trap; (h) a nozzle assembly, which is screwed to the motor tube; (g) an electric primer, which is inserted in any of the 26 nozzle holes; (1) a pressed iron spacer which fits into the base of the nozzle assembly and provides an air void between the nozzle assembly and the TNT bursting charge; (h) a bursting charge of TNT or a chemical filler contained in a fiber container; (m) a machined steel bursting-charge container; (o) a booster adapter, which screws into the bursting-charge case; (n) a base percussion fuze, which screws into the booster adapter. This fuze is similar to most German base percussion fuzes and arms by centrifugal force.

TYPES

There are three known types of these projectiles in existence, namely:
A. High Explosive (15 cm Wgr. 41 Spr.)—weight 70 lb.; length 36.6 ins.; maximum diameter 6.2 ins.
B. C. W. (15 cm Wgr. 41 Grünring)—content chemical
C. Smoke (15 cm Wgr. 41 Nb)—weight 79 lb.; weight of propellant 14 lb.

German: p. 356

21 cm Wgr. 42 Spr. Mit Hbgr. Z 35 K: 21 cm Rocket Projectile

21 cm Wgr. 42 Spr. Mit Hbgr. Z 35 K: 21 cm Rocket Projectile

This rocket is very streamlined and in outward appearance resembles an artillery projectile. All metal components of the body are machined inside and out and appear to be of mild steel.

A complete round of this ammunition is made up of the following components (see photograph above):

(a) Nozzle assembly containing 22 orifices evenly spaced around the rim of the nozzle. These orifices are set an an angle of 16° from the axis of the rocket. This angle gives the rocket clockwise rotation in flight besides providing forward thrust. In the center of the nozzle there is an ignition hole which receives the electric squib.

(b) Motor body having two bourrelet surfaces.

(c) High-explosive body containing 22.4 pounds of TNT. It is made of mild steel with fairly thick walls and is threaded on its base and screwed into the motor body.

(d) False ogive, which completes the streamlined contour of the rocket.

(e) Trap, a casting painted rust red. Between the trap and the nozzle there is a tinfoil disk which is used as a moisture and dirt seal.

(f) Black powder base igniter.

(g) Igniter wick, a celluloid tube containing a charge of quickmatch.

(h) Propellant charge consisting of seven sticks 21.67 inches long and 2.46 inches in external diameter.

(i) Spacer to hold the head igniter in place and allow for the proper ignition of the entire propellant.

(j) Igniter.

(k) Booster cup.

(l) Point-detonating fuze.

(m) Wooden actuating rod.

SPECIFICATIONS

Weight of projectile as fired         241.30 lb.
Weight of TNT bursting charge 22.40 lb.
Weight of propellant powder 39.50 lb.
Weight of high-explosive body 65.25 lb.
Weight of propellant body 87.75 lb.
Weight of nozzle assembly 5.12 lb.
Length 49.21 ins.
Diameter 8.27 ins.

German: p. 355

30 cm Wurfkörper 42 Spreng: 30 cm Rocket

30 cm Wurfkörper 42 Spreng: 30 cm Rocket

This rocket is packed in a wooden crate from which it may be fired in the same manner as the 28 cm rocket described on page 354. It is also fired from a rocket projector consisting of six welded metal frames mounted on a two-wheeled, split trailed carriage described on page 350.

This model has been selected to illustrate the construction of the motor assembly of a typical rotating rocket. The motor tube is 0.43 inch thick, closed at one end, and threaded inside to take the venturi block. Eighteen venturis are drilled in this solid block. The throat diameter of each venturi is 0.365 inch with an exit section of approximately 0.82 inch in diameter. The axes of the venturis are inclined at an angle of 12° 42′ so that the effluent gases cause the round to rotate. A threaded hole in the center takes the primer unit.

Seven tubular sticks make up the propellant charge composed of nitrocellulose and diglycol dinitrate.

German 30 cm Rocket

The sticks are supported at the venturi end on a grid. The center stick contains a length of quickmatch in a celluloid tube, and ending in a primed maintainer pellet. A small primer unit screwed into the steel venturi plug flashes directly on to the gun powder pellet at the end of the celluloid tube.

This motor unit is similar to that of the 15 cm Wurfgranate. However, because of the heavier charge in the 30 cm ammunition, the metal mesh has been introduced to prevent the maintainer pellet from being crushed by the central stick of the propellant charge if the rocket is dropped.

SPECIFICATIONS

Weight of filled motor unit         129 lbs., 10 ozs.
Weight of filled bomb 146 lbs., 4 ozs.
Weight of propellant charge 33 lbs., 3 3/4 ozs.
Length (overall) 47 ins.
Length of bomb 28.5 ins.
Length of motor tube 22.5 ins.
Diameter of bomb 11.8 ins.
External diameter of motor tube 8.56 ins.
Length of propellant charge 18.4 ins.
Burnt velocity 754 f/s
Range, maximum 4,976 yds.

German: p. 354.1 (June 1, 1945)