Tuesday 21 July 2020

German Explosive Ordnance - Rockets (Part 18)







German Explosives





28-cm H.E. Rocket, Spin Stabilized


Nature of Projectile: Multiple baseventing, spin-stabilized, pusher rocket.
Caliber: 280 mm

Filled Weight (complete round): 83 kilograms (183 pounds)
Overall Length (complete round): 1,190 mm (46.41 inches)

Nature of Fuze: Nose Percussion delay action
Nature of Filling: H.E.
Maximum Range: 2,339 yards.


Warhead
General Shape: Cylindrical canister with rounded ends, one of which receives the fuze and the other the tail unit.

Material: Sheet steel

Overall Length: 720 mm
Diameter: 280 mm
Wall Thickness: 1 mm
Weight of Filling: 36 kilograms
Filling: Amatol or TNT


Markings:
On Nose - 28 cm Wk. Spr.
On Body - 13 Mr. 5.6.42.G.


Method of Ignition: A separate electrical initiator enclosed in an aluminum tube and bakelite container, and which may be fired from a 4-volt battery, is screwed into the central drilling in the base.  For firing single rounds, initiators are provided, connected by 15 inches of two-strand insulated wire to a plug, and action is instantaneous on application of voltage.  For firing from Wurfgerat (four-frame stand), four initiators, externally similar in appearance, are provided, wired in series.  One only (tagged "0") is instantaneous and the remaining three (tagged "2", "4", and "6") include powder pellets so as to fire after intervals of 2, 4, and 6 seconds respectively.


Ignition Charge

Nature
Head: Compressed Gunpowder.
Base: Nitrocellulose in powder int he form of six-pointed, star-shaped flakes.

Weight
Head: (Unavailable)
Base: 10 grams

Container
Head: Flat, circular aluminum with open end towards propellant.
Base: Porous, rough-cloth bag.

Positioning
Head: In a pressed-steel housing supported by a flanged split ring.
Base: In center of grid.


Markings:
Head: None
Base: Wx. Man. St. P (2.25/23) dt1938/5 WO.7.842W.


Description: This is a spin-stabilized projectile consisting of a large warhead with a rocket motor of smaller diameter attached at the rear.  The projectile is electrically fired from the wooden crate in which it is carried or from a multiple launcher consisting of a number of frames of similar dimensions.


Warhead: The warhead is a thin steel shell sealed at the rear, where it has a flange threaded to take the rocket motor.  Two raised bearing surfaces on the body locate the projectile in the firing frame and also reduce lateral friction.  An adaptor in the nose of the warhead is threaded to take a nose percussion fuze and a gaine holder.


Rocket Motor: The rocket motor is in the form of a cylinder screwed into the rear of the warhead and closed at the rear by a plug in which are a number of offset venturi drillings.  The propellant, which consists of a single stick, is located at the forward end by a flanged metal spacing ring which also contains the ignition charge, and at the rear by a metal grid holding the rear ignition charge.  The base plug screws over the motor body and has a central drilling tapped to receive an adaptor for the electrical igniter.


Remarks: This rocket is designated the "28 cm Wfk. Sprg." 

The round is painted grey overall, with stencillings in black and white letters.








30-cm MEB H.E. Rocket, Spin Stabilized


Nature of Projectile: Multiple baseventing, spin-stabilized, pusher rocket.
Caliber: 300 mm

Overall Length (complete round): 48.44 inches
Overall Weight (complete round): 278 pounds

Nature of Fuze: Nose Percussion
Nature of Filling: Amatol
Maximum Range: 4,976 yards.


Warhead
General Shape: Elliptical with rounded forward end and truncated tail.

Material: Sheet steel

Overall Length: 29.5 inches
Maximum Diameter: 12.125 inches (across rib)
Wall Thickness: 0.109 inches
Diameter at Tail (External): 8.938 inches
Diameter at Tail (Internal): 8.625 inches
Diameter at Nose: 4.563 inches

Weights
Empty: 49 pounds 12 ounces
Weight of Filling: 98 pounds 6 ounces
Filling: 60/40 Amatol


Markings:
Stamped On Nose - 23.
Stamped in White approx. 4 inches below Fuze - 30 cm WK 42 Sp.
Stenciled on Rear Center: 13 Jg 29 9 42
Stamped on Lower End: 42, CKI.


Description: This projectile is similar in design to the 28- and 32-cm rockets, being spin-stabilized and consisting of a forward warhead to the rear of which is attached a rocket motor of smaller diameter.


Warhead: The warhead is constructed of two sections of sheet steel, a nose piece and a tail, the four sections being joined together by circumferential welds.  A single rib around the center of the projectile serves to reduce friction against the side of the launcher.  The nose piece is threaded to receive a nose fuze, Wgr. Z.50 and a gaine, and the tail internally threaded to screw onto the forward end of the rocket motor.  The H.E. filling consists of 96 pounds of amatol.


Rocket Motor: The rocket motor is of conventional design and consists basically of a cylindrical body and a base plug incorporating the venturi and igniter assemblies.  The body is machined internally and externally and is closed at the forward end, where it is threaded to screw on the tail of the warhead.  This end section is not flat but is slightly concave internally to permit a more even distribution of pressure.  The rear end of the body is threaded internally to receive the base plug which has 18 offset venturi drillings and a central drilling to take an electrical igniter.  The propellant, which consists of seven mono-perforate sticks, is located by two grids, one at each end of the motor body.  A celluloid tube containing a quickmatch train and plugged at each end by a gunpowder pellet, is located in the drilling in the central stick and transmits the flash from the igniter to the ignition charge at the forward end of the motor.



Remarks: The German designation for this round is "30 cm Wkf. 42 Spr."

The round is painted dark green overall, with black and white stencillings.





32-cm Incendiary Rocket, Spin Stabilized


Overall Length: 48.6 inches
Diameter: 13 inches
Total Weight: 174 pounds

Propellant Weight: 14.24 pounds
Length of Grain: 16 and ¼ inches
Diameter of Grain: 4 and  inches
Type of Filling: Kerosene mixture
Weight of Filling: 87.69 pounds


Description: This rocket consists of a large, bomb-shaped head, filled with an incendiary mixture and burster ignition tube, and a motor body to which the head is threaded.  The head has raised ridges fore and aft to provide bearing surfaces, and near the nose is a filling plug.  An adapter is threaded into the burster container, the base of the adapter containing a booster charge.  The burster contains two sets of one solid and one ring penthrite pellet.  Between the sets of pellets is located a magnesium filled ignition charge container, through the center of which passes a burster stick of penthrite.

The motor contains a single propellant grain with one central perforation and eight smaller perforations arranged at equal intervals around the central one.  Eight longitudinal grooves are formed along the exterior of the grain.  In each groove is fitted a tubular celluloid inhibitor.  Through the large central perforation is passed a length of quickmatch in a celluloid tube.  This serves to connect the head igniter with a primary ignition charge located in a cloth bag at the after end of the propellant grain.  The primary ignition charge and the propellant grain are supported by a metal grid attached to the venturi assembly.  The venturi assembly, drilled to form 26 jets at a 16 degree angle, is threaded to screw into the after end of the motor body.  A threaded hole in the base of the venturi assembly accommodates the electric igniter.


Remarks: The German designation for this round is "32 cm Wfk. M. Fl. 50"

This round is painted dark green overall.

Although recovered only with an incendiary filling, it is reported that this round may also contain a chemical charge.



Next Time: Rockets (Part 19)


Source: German Explosive Ordnance Vol. 1: Bombs, Rockets, Grenades, Mines, Fuzes & Igniters

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