Practice 11.5-lb. Mk I (Service), and Mk II (Obsolete)

Body Construction: The bomb consists of a nose casting, fitted with a striker as-sembly and a tail cone which constitutes a container for the filling, and is fitted with a central tube for a detonator burster. The nose casting is made of iron, internally thread-ed at the rear to receive the spigot portion of a central plug which closes the forward end of the tail cone. The interior of the nose is filled with lead, and has a cleanrance hole for the striker rod. The striker is secured by a cotter pin (removed when loaded), a safety pin spring-loaded outward, and a shear wire through the guide bush.

Tail Construction: The sheet-metal tail cone, constuting the container for the filling, is closed at the rear by a conical steel tail plug and at the forward end by a central plug which screws into the rear of the nose casting. A tapped hole is provided in the central plug for filling purposes. Secured to the tail plug is a tail tube having four fins, which carry a cylindrical strut. The tail tube is closed at the rear by a cap.

Suspension: The bomb is suspended by a single eyebolt, which threads into the bomb case.

Explosvie Components

Detonator burster No. 28 Mk I – consists of 10 grains fulminate of mercury and 7 C.E. pellets.

Smoke filling, Mk I – 1 lb. titanium tetrachloride, which produces white smoke when the detonator burster breaks open tail cone and exposes it to the atmosphere.

Flash filling – 1 lb. mixture of gunpowder and magnesium turnings, producing a brilliant white flash on impact.

Remarks: The Bomb Mk I with smoke filling is used for daytime practice. The flash-filled Mk I is used at night.

The Bomb Mk II is made in the U.S. of bakelite, but have now been scrapped.

Figure 57 - Practice 11.5-lb. Bomb