German Explosive Ordnance - Rockets (Part 17)

German Explosives

15.2-cm Anti-Aircraft Rocket, Fin Stabilized

Overall Length: 58.2 inches

Diameter: 7.09 inches

Total Weight: 150 pounds

Propellant Weight: 11 pounds 10 ounces

Length of Grain: 11.7 inches

Cable Length: 950 yards

Diameter:

Main Parachute: 11 feet

Pilot Parachute: 6 feet

Type of filling:

Upper H.E. Charge: RDX/Wax (95/5)

Lower H.E. Charge: RDX/Wax (95/5)

Weight of Filling:

Upper H.E. Charge: 2 pounds 6 ounces

Lower H.E. Charge: 1 pound 10 ounces

Description: This projectile is of the "aerial-wire-barrage" type and is used to project a steel cable into the air by means of a rocket.  One end of the cable is fixed to the ground and the other to a large support parachute and a smaller drag parachute.  When the cable has paid out, the parachutes are pulled from their housing.  The projectile is fin-stabilized and consists, from nose to tail, of the rocket motor, parachute housing, and upper and lower cable housing.

Rocket Motor: The rocket motor consists of a motor body, which is screwed into the parachute housing, and an ogival nosepiece containing a TNT destruction charge.  The motor body is a cylinder closed at the forward end and open at the rear.  There is no base plate, but the propellant gases are allowed to escape through four venturi drillings in the forward end of the parachute housing.  The propellant is a single, cylindrical, multiperforated stick and is ignited by means of an electrical base igniter, a train along the central drilling, and an ignition charge in a grid at the forward end.  Leads to the electrical igniter pass through one of the venturi drillings.  A delay fuze in the forward end of the motor body ignites the destruction charge in the nose piece.

Parachute Housing: The parachute housing, which is a cylinder closed at the forward end, serves not only to house the large main support parachute and the smaller drag parachute, but also as a base plug for the rocket motor.  The forward end has four venturi drilled obliquely in the sides of the body.

At the forward end of the parachute housing is a TNT destruction charge enclosed in asbestos.  Although this has a primer, there is no means of initiation; it is assumed, therefore, that this charge is set off by sympathetic detonation from the charge in the nose of the projectile.  Below this destruction charge is the main parachute wrapped in asbestos and below it the small drag parachute.

Cable Housing: The cable housing is constructed in two separate halves.  The upper half is attached to the base of the parachute housing and accompanies the projectile on its flight.  The lower portion of the housing has a flanged base, which fits into the mounting and remains on the ground.  The finned tail unit is spot welded to the upper half and fits over the lower portion.  This maintains the projectile in position until it is fired.  A slot is provided in two of the fins through which a wire is passed, holding the lower section in position; this wire should be removed before firing.

A continuous length of approximately 950 yards of 1/8-inch steel cable is coiled in equal lengths inside each portion of the cable housing.  The end of the cable in the upper portion is attached to the parachute, and the other end passes through a hole in the bottom of the lower portion and terminates in an eyebolt secured to the launching frame.

Operation: The actual barrage consists of the support parachute, drag parachute, and cable.  The projectile is evidently launched from some kind of frame (no specimen of this had yet been recovered, to which the lower portion of the cable housing is fixed.  When the propellant charge is ignited, the projectile climbs until, theoretically, the whole of the cable has paid out.  The drag parachute and the main support parachute are then withdrawn from the parachute housing and the main unit continues on its course, leaving the cable suspended in the air.

When the propellant burns out, the destruction charge in the nose piece, actuated by the delay fuze, destroys the rocket motor and parachute housing.  It is presumed that the charge in the forward end of the parachute housing is at this point set off by sympathetic detonation to assist in this destruction.

20-cm Anti-Aircraft Rocket, Fin Stabilized

Overall Length: 64.3 inches

Diameter: 8 inches

Total Weight: 159 pounds 3 ounces

Propellant Weight: 11 pounds 9.5 ounces

Description: This rocket is similar in design and operation to the 15.2-cm anti-aircraft rocket but is much cruder in construction.  The round consists of a rocket motor at the forward end, a middle compartment containing the parachute and the cable housing surrounded by the fin sleeve.

Operation: On firing, the cable housing remains on the ground, and the rest of the assembly is projected into the air, uncoiling the cable from its housing.  When the cable is completely unspooled, the parachute is withdrawn through the fin sleeve.  The separation of parachute and motor operates a pull igniter, which initiates a demolition charge contained in a central tube in the motor.

Remarks: The round is painted dark green overall.

21-cm H.E. Anti-Aircraft Rocket, Spin Stabilized

Overall Length: 49.2 inches

Diameter: 8.27 inches

Total Weight: 241.3 pounds

Propellant Weight: 39.5 pounds

Length of Grain: 21.67 inches

Diameter of Grain: 2.46 inches

Type of Filling: Amatol 40/60

Weight of Filling: 22.4 pounds

Description: This is a streamlined aircraft rocket projectile, consisting of an H.E. shell, externally threaded at the base to screw into the rocket motor and at the nose to receive a ballistic cap.  A booster container is threaded into the nose of the shell and receives the nose fuze.  A wooden actuating rod separates the fuze from the tip of the ballistic cap.

The motor body is a cylindrical steel body machined externally to form fore and aft bourrelets.  A venturi assembly, drilled to form 22 jets, threads into the base of the motor.  The jets are inclined at an angle of 16 degrees to impart a rotary motion to the rocket in flight.  An electric squib is threaded into the center of the venturi assembly.  The propellant charge consists of 7 single-perforated grains supported by a metal grid at the after end.  A ring-shaped black powder igniter is placed at the base of the charge and a second igniter is located at the forward end of the charge.  These two ignition charges are connected by a length of quickmatch in a celluloid tube, which passes through the perforation of the central propellant grain.

Remarks: The German designation for this round is "21 cm Wgr. 42 Spr."

This round is painted green overall.

Next Time: Rockets (Part 18)

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

German Explosive Ordnance - Rockets (Part 16)

German Explosives

8.8-cm H.E. Hollow Charge Rocket, Fin Stabilized

Nature of Projectile: Multiple-venting, non-rotating, fin-stabilized pusher motor.

Caliber: 8.87 cm

Overall Length (Complete round): 19.4 inches

Total Weight (Complete round): 5 pounds, 13.5 ounces

Nature of Fuze: Instantaneous nose percussion

Nature of Filling: Cyclotol

H.E. Head

General Shape: Cylindrical main body; truncated, conical impact cap and rear section

Overall Length: 10.47 inches

Diameter of Bearing Surface: 3.494 inches

Depth of Cavity Liner: 3.67 inches

Main Body Wall Thickness: 0.045 inches

Impact Cap Wall Thickness: 0.09 inches

Cavity Liner Wall Thickness: 0.06 inches

Forward Diameter, Impact Cap: 1.356 inches

Weight (Empty): 4 pounds 0.75 ounces

Weight (Filling): 1 pound 7.14 ounces

Markings:

Cylindrical Portion of Body:

Stenciled in Purple - WaA 424

Stenciled in Black - Tpn 2.3 44D LM 4312

Rear Portion of Body:

Stenciled in White - 43 fcc 47

Description: This projectile is fired from the mobile anti-tank rocket launcher 8.8cm Raketenwerfer and is similar in appearance to the 8.8cm Raketen Panzerbuchse Granate 4322.  The projectile, which is fin-stabilized, consists basically of an H.E. head, a motor tube, and a tail-fin assembly.

H.E. Head: The head of the projectile consists of the body containing the cyclotol hollow-charge located by a cavity liner and an impact cap.  The impact cap is flanged at the read end to bear against the cavity liner and is fitted at the forward end with an adapter, threaded to receive either of two nose percussion fuzes, the A.Z. 5095 or the A.Z. 5095/1.

Two pressed flanges at the forward end of the body secure the impact cap and the cavity liner.  The rear end of the body is conical in shape and fits over a tail adapter which forms the junction with the motor tube.  A reinforcing sleeve is pressed into position over the cylindrical portion of the body and provides the forward bearing surface of the projectile.

At the lower end of the cavity liner is a flash tube below which is located the gaine; this consists of an aluminum cup containing a charge of PETN and wax and a detonator.  The gaine is separated from the motor tube by a wooden plug which acts as a buffer and which also provides the necessary thermal insulation between the motor and the gaine.

Motor Tube: The forward end of the motor tube is sealed and threaded to screw into the tail adapter.  The rear is screwed into the venturi block.

The propellant consists of a single stick with 14 small longitudinal perforations and a single axial drilling of larger diameter.  Three lands around the outside of the stick keep the propellant from touching the inside of the tube and ensure an external burning surface.  Two grids, one at each end, are used to support the propellant; each grid is a triangular metal platform on three legs.  At the rear there is a wire mesh between the grid and the propellant to prevent any unburnt particles from blocking the venturi drillings.

Between the grid and the propellant at the forward end is an ignition charge mounted so that it is free to burn on both surfaces.  A celluloid tube, containing a thin strip of what appears to be nitrocellulose powder, is located in the axial drilling of the propellant; both ends of the tube are capped with a block of black powder.  This train serves to transmit the flash from the primer to the ignition charge at the forward end of the motor tube.

Tail-Fin Assembly: The tail-fin assembly consists of a venturi block, stabilizing fins, obturator, and percussion igniter.

The venturi block, which is screwed over the end of the motor tube, has six venturi drillings parallel to the axis of the projectile.  These are each formed by two drillings of different diameter; instead of taper there is a sudden step from the smaller to the larger diameter.  The block is drilled and tapped in the center to receive the firing-pin adapter.  A collar on the rear of the firing-pin adapter holds the obturator in position around the rear of the fin assembly.  A percussion cap is mounted in the forward end of the firing-pin adapter, immediately in rear of the quickmatch train.  The adapter is machined down to a separation point near the rear end; when the projectile is fired, the adapter severs, and the rear portion remains in the breech together with the obturator.

The six stabilizing fins are mounted in three pairs around the venturi block and are strengthened by a sleeve fitted around the fins and under the forward lip of the obturator.

Remarks: The German designation for this round is "8.8 cm R. Pz. B. Gr."

This same round, modified for percussion firing, is used in a single tube, two-wheel launcher, the "8.8cm Raketenwerfer 43"

15-cm H.E. Rocket, Spin Stabilized

Overall Length: 38.55 inches

Diameter: 6.22 inches

Total Weight: 70 pounds

Propellant Weight: 14 pounds

Type of Filling: TNT

Weight of Filling: 4.5 pounds

Description: This rocket resembles an elongated gun projectile with a bulbous nose cap.  The round consists of a forward motor body containing the seven single-perforated propellant grains and the after H.E. container.  An enlarged diameter ogival ballistic cap is threaded to the forward end of the motor, and a venturi assembly with 26 drilled jets threads over the base of the motor.  The venturi assembly also is threaded externally at its after end to receive the machined steel bursting charge container.  An H.E. charge in a fiber container is placed in the steel shell case, separated from the base of the motor by an iron spacer to provide an insulating air void between the H.E. and propellant charges.  A booster adapter, containing the booster charge and threaded to receive the base fuze, screws into the base of the H.E. shell.

The propellant grains are supported fore and aft on a pair of metal grids.  A black powder igniter charge is placed over the rear grid, and a second black powder charge is contained in an aluminum holder between the head of the motor and the forward grid.  The two charges are connected by a black powder filled cellulose tube, which passes through the perforation of the central grain.  An electric igniter is fitted into 1 of the 26 jets.

Remarks: This round is designated "15-cm Wgr. 41 Spr."

15-cm Smoke and Chemical Rocket, Spin Stabilized

Overall Length: 40.16 inches

Diameter: 6.22 inches

Total Weight: 79 pounds

Propellant Weight: 14 pounds

Type of Filling: Smoke Composition

Weight of Filling: 8.5 pounds

Description: Except for the shell after body, this rocket is identical to the 15-cm H.E. rocket.  The motor arrangement is identical to the latter, and the shell similarly attached to the motor.  The shell for the smoke rocket is 4.5 inches longer than that for the H.E. round and is somewhat differently constructed.  The shell consists of a thin-walled steel cylinder with a long burster charge container threaded into the after end.  This container holds 3.05 pounds of picric acid.  The container is threaded to receive a base fuze and a short exploder.  The smoke composition is located between the shell body and the outer wall of the burster container.

Remarks: The German designation for this round is "15-cm Wgr. 41 Nb."

This round may also be employed as a chemical shell.  When so used, the German designation is "15-cm Wgr. 41 Grunring"

Next Time: Rockets (Part 17)

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

German Explosive Ordnance - Rockets (Part 15)

German Explosives

8-cm R Lg 1000 Rocket

Description: The 8.6 cm R lg 1000 (flare) and the 8.6 cm R Dg 1000 (wire) differ only in the contents of the body.  The flare rocket contains a parachute-suspended flare having a burning time of 30 to 35 seconds.  The wire rocket contains, in place of the flare element, a spool of wire which is suspended by the parachute.  No explosive is attached to either the parachute or the wire.  

The flare element is contained in a light metal can which is directly above the base delay pyrotechnic fuze.  The parachute fits above the wooden plug midway up the tube.  The forward end of the body is closed with a light ballistic cap which is pushed out by the ejecting parachute-flare unit.  The base of the body is closed with a wooden block which rests on the lip of the adapter.  The adapter is welded to the body and serves as a bourrelet as well as the attachment between the motor and the body.  The pyrotechnic time base fuze of 8.5 seconds burning time is ignited by the burning of the propellant in the rocket motor.

The motor is similar to that of the 8.6 cm R Sgr L/4.8 except that the nozzles are changed to accommodate the reduced propelling charge.

The black powder propellant grains 100 mm long and 70 mm in diameter, weighing 750 grams, is mounted in a manner similar to the Spgr L/4,8.  The diglycol propellant consists of two concentric cylinders 80 mm in length and having diameters of 70/40 and 35/5 mm, weighing 420 grams.  A flash tube runs through the central 5-mm diameter hole of the inner grain from the rear igniter up to the forward igniter.  The igniters and grains are held in position by a three-armed grid at each end of the grain.  It is indicated that the grid is of plastic material instead of the usual metal construction

Motor:

Propellant: Black powder, Diglycol

Nozzles: 8, 4

Throat Diameter: 4,5, 5.45

Cant angle: 9 degrees

Nozzle K: 234, 480

Performance:

Thrust: 150

Burning Time: 1.2

Impulse: 80

Range: 1,000 meters

Nozzle:

Diameter of Jet ring: 69±0.1 mm

Entrance cone angle (first): 60 degrees

Entrance cone angle (second): 15 degrees ±15 min

Length of cone (first): 1.5 mm

Length of cone (second): 5.5 mm

Throat Length: 3.0±0.5 mm

Expansion cone angle: 1 degree ±10 min

Launching: The launcher used in the various tests consists of a single barrel weighing 40 kg.  It is denoted as the 8.6 cm R Ag M 42.

8.6-cm Anti-Aircraft Rocket (Spin Stabilized)

Overall Length: 16.5 inches

Diameter: 3.39 inches

Total Weight: 11 pounds

Description: This rocket is constructed of steel in four sections; Projectile body, parachute container, cable container, and rocket motor.

Projectile Body: The projectile body consists of a cylindrical container, internally threaded aft to receive the rocket motor and open at the forward end to receive the parachute container.  The body of the projectile has a raised pressing near the center of its length to provide a forward bearing surface while in the projector.

Parachute Container: The parachute container is divided longitudinally into two halves held together by adhesive tape and is a sliding fit in the forward end of the body.  The parachute measures 20 inches deep by 36 inches in diameter when open, and is made of yellow silk with a red stripe running down the center of each gore.

Cable Container: The cable container is located in the body just aft of the parachute container.  The cable container is nothing more than a steel cylinder filled with 310 feet of steel wire.  The forward end of the wire is attached to the parachute shrouds.  Separating the cable container from the head of the motor is a perforated wooden distance piece, which is recessed to form a seating for an ejection charge and centrally bored to house a delay tube containing black powder.

Rocket Motor: The motor consists of a steel tube 1/8-inch thick, closed at its forward end, which is drilled centrally and threaded to receive the delay tube.  The propellant grain is a single solid cylinder, and is primed at the base end with gunpowder.  The motor is closed at the after end by a threaded venturi assembly drilled around the outer periphery to form 8 jets.  A percussion cap is fitted in a central hole in the base of the venturi assembly.

Operation: Near the end of the burning period of the rocket motor, the delay tube is initiated by the heat of the burning propellant and eventually ignites the ejection charge at the base of the cable container.  The explosion of this charge ejects the cable and parachute containers from the forward end of the body and splits open the parachute container.  The parachute opens and withdraws the coiled cable from its falling container.

Remarks: This round was originally designed to protect small naval vessels and merchant shipping from low-level attack, but it may have played a ground role as well.  The ceiling of the rocket is estimated at about 8,000 feet.

Next Time: Rockets (Part 16)

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

German Explosive Ordnance - Rockets (Part 14)

German Explosives

8-cm Raketen Sprenggranate (H.E. Aircraft Rocket)

Caliber: 78 millimeters

Overall Length: 28.5 inches

Weight (complete round): 15 pounds 3 ounces

Filling: Flaked TNT

Warhead Material: Steel

Rocket Motor Material: Steel

Warhead Length: 8 inches

Warhead Diameter: 3 inches

Rocket Motor Length: 12.8 inches

Rocket Motor (outside): 3.07 inches

Rocket Motor Diameter (inside): 2.75 inches

Rocket Motor Weight: 4 pounds 5.25 ounces

Venturi Material: Steel

Venturi Length: 7.48 inches

Outside length of fins: 5.31 inches

Rear diameter across fins: 

-External: 7.87 inches

-Internal: 3.34

Venturi Weight: 2 pounds 0.25 ounces

Inlet Maximum Diameter: 2.48 inches

Inlet Minimum Diameter: 0.782 inches

Inlet Length: 0.92 inches

Throat Diameter: 0.782 inches

Outlet Maximum Diameter: 1.653 inches

Outlet Minimum Diameter: 0.782 inches

Grid Diameter: 2.72 inches

Grid Thickness: 0.51 inches

Grid Weight: 3 ounces

Propellant: Double base powder in mono perforated stick form.

Description: This is a fin-stabilized projectile with an appearance typical of small caliber aircraft rockets.  The internal arrangement of the projectile suggests that it was possible copied or adapted from a standard Russian aircraft rocket.  Although this rocket almost certainly was designed primarily as an aircraft weapon, it was also fired from a multiple-frame ground launcher known as the 8-cm Raketen Vieflachwerfer.  The projectile consists basically of an H.E. warhead, a rocket motor, and a tail unit incorporating a single venturi and stabilizing fins.

Warhead: The warhead of the projectile is a steel cylinder with an ogival nose into which is built a fuze system.  The rear of the head is closed by an adapter plug which also forms the junction with the rocket motor.

The main H.E. filling consists of a pressed flake TNT and is built up from three perforated pellets which fit around the exploder tube incorporated in the fuzing system.  At the nose end is a small cardboard washer; at the base are two waxed-paper washers; and around the exploder magazine is a waxed-cardboard tube.  Between the shell wall and the explosive is a thin layer of bituminous material.  The outer surfaces of the pellets are waxed.

Rocket Motor: The body of the motor is formed by a cylinder which is machined down slightly between the ends.  The forward end of the cylinder is threaded internally to screw over the adapter plug which forms the junction with the warhead.  Four studs in the body, two at each end, guide the projectile in the launcher.  The base of the motor body is closed by the motor closing plate, which is in the form of a single venturi to which four stabilizing fins are spot welded.

The propellant consists of six sticks, of which two are slightly shorter than the other four.  The four longer sticks are located by a supporting grid which is a push fit in the venturi assembly.  The other two sticks are supported on the two primary igniters attached internally to the walls of the rocket motor.

The ignition system consists of two ignition charges, one at each end of the propellant, and a primary igniter.  The primary igniter is in the form of two copper tubes, each screwed internally over the end of the steel guiding studs which pass through the motor body at the rear end.  A brass rod, insulated by a rubber sleeve, passes through the guiding stud and bears against a brass contact inside the copper tube.  This contact passes through the tube into a small cardboard container holding a loose composition charge of gunpowder.  Wires from the contact to the walls of the copper tube serve to ignite the charge.  The circuit is presumably formed by two leads, one to the brass rod in each guiding stud, and is grounded to the rocket body.

Fuzing System: This rocket has a fuze which has been designed specifically for it.  The fuze consists of a steel nose piece which contains a light alloy striker supported by a light creep spring.  Below the nose piece is a steel magazine tube, into the forward end of which is screwed the detonator housing.  Directly below the magazine tube is the arming mechanism which consists of a metal sleeve, containing a spring loaded screw and the plunger.  Holding the spring loaded screw and the plunger in position is a fusible metal ring.  When assembled, the plunger fits into the lower end of the magazine and the booster pellets rest on it.

When the rocket is fired, the heat of the burning propellant is conducted through the wall of the spigot and melts the fusible metal ring.  The plunger, magazine, and detonator are then free to move forward under the action of the spring.  The extent of this forward movement depends upon the acceleration of the rocket.  Approximate measurements indicate that if this is less than 40-50 grams the detonator is sufficiently forward to be fired by the striker.

8.6-cm H.E. Rocket (Spin Stabilized)

Nature of Projectile: Multiple base-venting, spin-stabilized pusher rocket.

Caliber: 8.6 centimeters

Overall Length: 16.25 inches

Overall weight: 17 pounds 15 ounces pounds

Nature of filling: H.E.

Nature of the fuze: Base

Warhead Length: 9.55 inches

Warhead Diameter: 3.35 inches

Type of Filling: Cast TNT

Rocket Motor Length: 6.7 inches

Length of Propellant Chamber: 6.08 inches

External Diameter: 3.18 inches

Internal Diameter: 2.94 inches

Weight of Filled Motor: 6 pounds 12.25 ounces

Propellant Length: 5.9 inches

Diameter of Propellant: 2.78 inches

Weight of Propellant: 2 pounds 7.75 ounces

Analysis:

-Potassium Nitrate: 75.5 percent

-Carbon: 15.35 percent

-Sulphur: 9.15 percent

-Volatile Material: 0.86 percent

Description: This rocket consists of a H.E. head, a motor, and a venturi assembly.  An integral base fuze, centrifugally armed and pressure fired, is located int he base of the H.E. head.

The H.E. head threads over the rocket motor housing, which contains a single, multi-perforated, propellant grain.  A venturi assembly, with eight jets drilled in it, is threaded to the base of the motor.  A single threaded hole in the center of the venturi assembly contains a percussion primer.  On the forward end of the motor housing is a fitting which receives one of three interchangeable delay trains.  The rockets bear markings to indicate which of the delay trains have been assembled.  Those marked "/400/" and "/800/" contain, in addition to the delay train, a fuze with a striker retained by four arming balls and a spring collar.  A light anti-creep spring is placed between striker and the detonator.

Centrifugal force causes the balls to move outward against the collar and arm the fuze.  The delay train is initiated by the propellant grain, and when the delay expires, the pressure developed forces the striker against its spring and into the detonator.  Impact with some resistant object before the expiration of the delay will force the striker into the cap.  In the case of the round marked "/600/" no striker mechanism is included, and the delay initiates the detonator and booster directly, giving only self-destroying action.

Remarks: This is a naval round, designated "8.6 cm R. Spr. 400 Wsm. (600 Wsm, 800 Wsm)."

The H.E. head is painted canary yellow overall; the motor body, dark green.

It is estimated that this projectile would reach a maximum height of 8,000 feet, if fired at a quadrant elevation of 90 degrees.

Next Time: Rockets (Part 15)

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

German Explosive Ordnance - Rockets (Part 13)

German Explosives

7.3-cm Propagandagranate 41

Weight (w/o Leaflets): 7 pounds 3 ounces

Length Overall: 16.1 inches

Weight of the Propellant: 1 pound 1 ounce

Weight of Propellant Unit: 3 pounds

Maximum Diameter: 2.85 inches

Description: The projectile consists of two steel tubes, screwed into a central joint.  The lower tube contains the rocket motor and the upper tube serves as a container for the leaflets.  The projectile is spin stabilized and is fired from the Propagandawerfer, which is a single launching tube.

The rocket motor is formed by the lower tube and a screwed-on base plug.  The base plug has 12 venturi set in 2 rings; those in the inner ring are straight and those in the outer ring are offset.  A copper percussion cap is located centrally in the base of the plug.

The propellant consists of a cylindrical stick with nine longitudinal drillings.  One of these is central, and the other eight are in a ring around the central drilling.  An ignition charge is located in a holder at the forward end of the propellant.  This is fired by the flash from the percussion cap passing up the central hole of the propellant.

The upper tube is the leaflet container and it is closed by a bakelite cap.  The leaflets are contained within a cylinder split longitudinally and are wrapped around a steel spring which is kept under compression.  Below the leaflets, one bakelite washer and two cardboard washers, is the bursting charge, incorporating a delay train which is fired by the heat from the ignition charge for the propellant.

Operation: The operation of this projectile is very simple.  When the heat from the ignition charge ignites the bursting charge, the contents of the upper tube are ejected; as the split cylinder emerges, it falls apart and allows the compressed spring to scatter the leaflets packed around it.

7.3-cm Raketen Sprenggranate

Caliber: 7.29 centimeters

Overall Length: 11.09 inches

Overall weight: 6 pounds

Nature of the fuze: Nose percussion

Warhead Material: Steel

Overall Length: 4.22 inches

Maximum Diameter: 2.85 inches

Diameter at Nose: 0.81 inches

Wall Thickness: Varies from 0.23 inch aft to 0.12 inch forward

Weight of Filling: 0.62 pounds

Overall Length (Body Tube): 6.34 inches

Overall Diameter (Body Tube): 2.6 inches

Wall Thickness (Body Tube): 0.1 inches

Overall Diameter (Base): 2.86 inches

Overall Height (Base): 1.29 inches

Number of Venturi: 14

-7 offset (outer circle)

-7 straight (inner circle)

Description: This is a spin-stabilized projectile of conventional design, consisting of a warhead and a rocket motor.  The projectile is essentially the same as the 7.3cm propagandagranate 41, except that a warhead provided with a percussion fuze and self-destroying delays has replaced the leaflet container.

The projectile is fired from the Fohn Gerat, a 35-frame launcher with fast elevating and transverse gears.  The launcher is capable of firing 35 rockets simultaneously.

The self-destroying feature of the rocket plus the characteristics of the launcher suggest that the projectile is intended for use against low flying aircraft in the form of barrage fire.

Warhead: The warhead is ogival in shape and open at the rear where it is threaded internally to receive the rocket motor.  The explosive filling is a preformed charge of 280 grams of RDX/TNT/wax pressed in a block and wrapped in wax paper.

The warhead is double fuzed, being fitted with a nose percussion fuze and a self-destroying base fuze.  The RAZ 51 is screwed directly into the nose of the warhead.  In the base of the charge is a cavity which accommodates the self-destroying delay, located in a tube screwed into a metal plug int he forward end of the motor.  The delay consists of a quick-fire igniter, initiated by the motor ignition charge, and what appears to be a tracer composition.  When the tracer composition burns out, it flashed through an orifice into a primer-detonator which detonates the main charge.

Rocket Motor: The rocket motor consists of a plane cylindrical body and a cup=shaped base plate.  The body is screwed into the warhead at the forward end and into the flange of the base plate at the rear.  The forward end of the rocket motor has a flange below which is located a metal closing plate which separates the warhead from the propellant compartment and also holds the rear end of the self-destroying assembly for the explosive charge.  Below this plate is a stamped metal supporting ring containing the ignition charge for the propellant.

The base plate, which screws on the rear end of the body, has seven outer offset venturi, seven straight venturi, and a central drilling for a percussion primer. 

The propellant charge consists of a single cylindrical stick with a central perforation and eight outer perforations.  Raised ribs around the circumference of the propellant serve to keep it clear of the motor body and permit external burning.  Two 1/8-inch blocks of powder, cemented tot he base of the charge, act as spacers and keep the venturi free from obstruction.

The charge is ignited by the flash from the percussion primer.  The flash is transmitted along a celluloid tube in the central drilling to the ignition charge at the froward end of the propellant.  The celluloid tube is of conventional design.  It contains a quickmatch train and is closed at each end by a cylindrical block of gunpowder.

Next Time: Rockets (Part 14)

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

German Explosive Ordnance - Rockets (Part 12)

German Explosives

A-9 / A-10 Long Range Missile

Description

The A-9 is similar in appearance and results to the A-4b but is of different internal construction.  It was proposed to develop and manufacture the A-9 in place of the A-4; however, this would require much reconversion and the A-4b, which could be put into operation much quicker, was being pushed as a stop-gap.  It was to have a Salbei-Visol rocket motor very similar to the missile Wasserfall.  It is shot into the air like a V-2 and vent toward the target, but rather than falling, it glides over the target where it goes into a vertical dive.  It would travel about 600 km in 17 seconds.

A proposal was made to launch it from a catapult at supersonic speed to increase the range.  It was also proposed to install a pressurized cabin and use a human pilot.  The pilot would drop the warhead on the target and then return to his base.  A retractable landing gear would be used in the landing which, it was felt, could be carried out at a speed as low as 160 km/h. 

Although the A-10 was never built, the calculations were completed for this unit which was to be used as an assist take-off motor for the A-9.  It supplies a thrust of 200 tons and would be jettisoned after it had served its purpose.  When the A-10 is jettisoned, the A-9 would have a velocity of 1,200 meters per second and the A-9 motor would begin to function.  The ultimate velocity was expected to be 2,800 meters per second.  The A-9/A-10 combination was expected to have a range of 5,000 km. 

It was also proposed to use a human pilot in this combination.

Next Time: Rockets (Part 13)

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