(Fig. 22)

The H.E. bomb, Model 38, for the 8 cm mortar (Gr.W. 34 8 cm) contains an ejection charge inside its lightly attached head which, after impact, throws the body into the air where the bursting charge is detonated.

The bomb is painted deep olive green and is stencilled in black. The stencilling includes the H.E. numeral "14" on the head indicating a bursting charge of T.N.T. and the model number "38" below the weight class marking on the streamlined portion of the body. Ex-ternally the bomb has the same appearance as the dull red Model 34 bomb described in Pamphlet No. 6 but, in the absence of markings, it can be identified by the presence of four equally spaced pins in the second rib of the parallel protion and four similarly spaced grub screws in the head just above the parallel protion. Al later model, Model 39, has only the four screws in the head. A bomb, filled and fuzed, bearing the weight class marking for Class II, weighed 7 lb. 5 oz. 8 drs.

The bomb consists of three main parts, the head, the body and the tail unit.The tail unit is the same as that of the Model 34. The head extends down to the parallel portion of the bomb and fits over a rim formed on the closing plate in the top of the body. The head is secured to the side of the closing plate by four equidistant screws inserted from the exterior and contains an ejection charge in a celluloid capsule. The body, containing the bursting charge, is closed at the top by a circular closing plate which rests on an internal shoulder in the body and is secured by four pins also inserted from the exterior. The closing plate is recessed from the top having a circumference rim which fits into the head. A screwthreaded hole is formed in the centre of the closing plate for the insertion of the delay chamber. The delay chamber consists of an inverted cup with a small cen-tral ori-fice in the closed upper end. Externally the chamber is screwthreaded and flan-ged near the top for insertion in the closing plate and below this it is reduced in diameter and screwthreaded to receive an exploder container assembled at the base end.

The ejection charge in the head of the bomb, consisting of 12.32 grams of nitrocellulose powder in the form of porous green cylindrical grains, is contained in a cellulose capsule which is shaped to fit the cavity in the head and the recess in the closing plate. A cellu-loid cup set in the top of the capsule, beneath the fuze, contains an ignition charge con-sisting of pressed gunpowder, primed with a white ignition composition. The composition consists of lead thiocyanate, nitrocellulose, sulphur and potassium perchlorate and is also used to seal five holes in the base of the capsule above the delay chamber.

The bursting charge, contained in the body below the closing plate, consists of 13 oz. 12 drs. of T.N.T. with a short central cavity to receive the exploder container.

The small P.E.T.N. delay gaine (kl.Zdlg. 34 m.V.) housed in the exploder container is des-cribed in this pamphlet as a separate item. The fuze, Wgr.Z. 38, is included in the des-cription of the 5 cm bomb in Pamphlet No. 4.

The primary and augmenting cartridge were the same as those used for the 34 bomb (see Pamphlet No. 6) but four augmenting cartridges are now being used, instead of three, to increase the range of all 8 cm bombs.

The composition of the 10 gram double base flake propellant (Ngl.Bl.P. -12.5- (1 x 1 x 0.2) used in the primary cartridge consists of 59.92 per cent of nitrocellulose (Nitrogen content 13.36 per cent) and 39 per cent of nitroglycerine and includes 0.86 per cent of ethyl centralite and 0.22 per cent of graphite. The initiator composition in the cap con-sists of 37.5 per cent of lead styphnate, 4.2 per cent of tetrazine, 7.4 per cent of anti-mony sulphide, 12.4 per cent of calcium silicide and 38.5 per cent of barium nitrate. This composition is of approximately the same analysis as that of the "Sinoxid" cap known be-fore the War.

The composition of the double base ring propellant in the augmenting or secondary cart-ridges consists of 60.61 per cent of nitrocellulose (Nitrogen content 13.35 per cent), 38.29 per cent of nitroglycerine, 0.7 per cent of akardite and 0.4 per cent of graphite. The weight and designation of the propellant in each of the cartridges as indicated by the markings, is 9 grams of Ngl.Rg.P. 12/5. The size, when three augmenting cartridges are provided, is (0.4-70/35). The size of propellant in the rounds provided with four cart-ridges is (0.4-60/30).

On impact, the flash from the detonator of the fuze, with the assistance of the ignition charge in the top of the capsule, ignites the nitrocellulose ejection charge. The explosion of the charge ejects the body of the bomb from the head and, at the same time, initia-tes the gaine through the orifice in the top of the delay chamber. The delay resulting from the passage of the flash through the orifice and the chamber, also the delay arran-gement in the top of the gaine, provides a time interval, reported to be about 0.7 of a second, between impact and the detonation of the bursting charge. The height to which the bomb will be thrown in this time depends upon the nature of the ground. Burst have been reported at heights between 20 and 60 feet (nature of ground not specified) but it is understood that the bomb is intended to detonate at heights between 3 and 20 feet.

Fig. 22