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 hav-ing 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. (See fig. 208.)

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 welded to the body and serves as a bourre-let as well as the attachment between the motor and the body. The pyrotechnics 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 nozzle are chan-ged 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 in-ner grain from the rear igniter up to the forward igniter. The igniters and grains are held in position by a three-armed grid each end of the grain. It is indicated that the grid is of plastic material instead of the usual metal construction.

Propellant: Black powder, diglycol.
Nozzles: 8, 4.
Throat diameter: 4.50, 5.45.
Cant angle: 9°.
Nozzle K: 234, 480.

Thrust: 150.
Burning time: 1.20.
Impulse: 80.
Range: 1,000 m.

Diameter of Jet ring: 69 ± 0.1 mm.
Entrance cone angle (first): 60°.
Entrance cone angle (second): 15° ± 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: 1.0° ± 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.

Figure 208 – 8.6-cm Illuminating Rocket (Naval)