GENERAL. In July 1944, a new series of 8.6-cm R.Spgr's was designed; the L/4.5 being the smallest rocket of the new series. The nozzle plate is threaded on to the motor tube and the loose motor closure design is employed. The body of the projectile has been lightened and the base fuze cavity eliminated. A KlAZ 40 impact-firing nose fuze is used in place of a self-destructive pyrotechnic time fuze that is used with the Spgr L/4.8. (See fig. 222.)

DESCRIPTION. The ignition train for the motor consists of a percussion cap, rear igniter of granular black powder and a flash tube running up the central hole of the inner propel-lant grain to the forward igniter. The forward igniter consists of a 30-mm diameter disk of incendiary material, which is not black powder.

The propellant grains are two concentric cylinders, 130 mm in length, having diameters of 70/40 and 35/7 mm and weighing 680 grams. The grains and igniters are held in place by a light three-armed grid of plastic.

Propellant: Diglycol.
Nozzles: 4.6.
Throat diameter: 6.90, 5.25.
Cant angle: 12°.
Nozzle K: 460, 525.

Thrust: 243.
Burning time: 1.22 minutes.
Impulse: 116.
Velocity (maximum): 250 m/sec.
Range: 3,500 m.

REMARKS. This rocket has the same design factors as shown for the 8.6-cm RLg 1000 rocket except for the throat diameter and uses the same type launcher.

Figure 222 – 8.6-cm R.Spgr L/4.5 Rocket