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