(Fig. 35)

The grenade is oval in shape and is dark grey with a bright blue ball cap. The cap is con-nected by a cord to a friction igniter which is initiated by unscrewing the cap and pulling it with the cord attached immediately before throwing. The weight of the grenade is 7 oz. 8 drams. The bursting charge weighs 3 oz. 14 drams. and consists of ammonium ni-trate (80 per cent), T.N.T. and wood meal. The charge is in the form of a loose powder.

The body is made of thin steel and consists of two portions spun together and closed at the head by a flange formed on the steel bush which receives the igniter and carries the steel pocket for the detonator. The bush is screw-threaded to receive the igniter and is spun to a flange formed on the pocket.

The igniter (Brennzünder 39) consists of a short brass or steel body, screw-threaded at the head to receive a square nut and the ball cap and at the base for insertion in the bush. An internal screw-thread is formed in the base end to receive the delay unit. The body contains a friction composition through which passes the pull wire. The lower end of this wire is coiled to provide the resistance to the pull. The upper end of the wire has a loop through which is threaded a two-and-a-quarter inch length of cord. The cord at its outer end is attached to a loose washer within the ball cap. When the cap is screwed to the grenade the slack of the cord is stowed inside the cap. The delay unit consists of a short steel tube filled with compressed powder and is screw-threaded to receive the detonator. The igniter is packed fitted with a moulded transit cap in place of the deto-nator.

A similar igniter with a red ball cap and a shorter delay (about one second) is used in booby trap devices.

The detonator may be of steel with a screw-threaded for assembly with the igniter or an aluminium one of the No. 8 A.S.A. type with a perforated disc pressed in on top of the filling. The detonator is packed separately and is pushed over the delay tube of the igni-ter when the grenade is prepared for use.

When the ball cap is unscrewed and the cord pulled the friction composition is ignited as the pull wire is drawn through it. The flash ignites the compressed powder in the delay tube which burns through and initiates the detonator.