1¼-lb. Incendiary Bomb Mk I (Obsolescent)

Weight

Filling

Delay

Color

Description: The empty bomb consists of a cylindrical tin-plate body which has an externally threaded neck, bakelite adapter and safety cover, zinc-alloy chamber, tin-plate cup securing cap chamber, and rubber washer. The body is filled with an incendiary composition and an ignition system which comprises an igniter unit and fuse adapter.

The fuse assembly consists of a rim fire cap secured to a length of safety fuse, which should give a delay of approximately five seconds. The cap chamber is passed over the safety fuse onto the sleeve of the rim fire cap. A length of copper tube is positioned over the fuse and secured by crimping. The igniter unit consists of igniter composition housed in a tin cup. On top of the igniter composition is a primed cambric disc and a pa-per sleeve.

To assemble the whole ignition system, the fuse assembly is inserted through the ba-kelite adapter and the free end of the fuse tube is secured to the paper sleeve in the ig-niter unit. The cap chamber of the ignition system is secured in position by screwing the cup securing cap chamber onto the adapter. The adapter with complete ignition system is screwed onto  the neck of the bomb body, the igniter unit positioning itself in the pa-per cup in the body. The safety cover is screwed down to the rubber washer, housed in the adapter recess, thus forming a seal. A patch of adhesive tape is affixed to the adap-ter and safety cover. This prevents removed of the safety cover during transit.

Operations: Remove the adhesive tape and safety cover. Place the bomb on its base in the required position. Strike the cap with a hard surface. The bomb is not to be touched after striking the cap.