BOMBS USED IN:

FUNCTIONING

ARMED CONDITION

FUZES USED WITH

MAX. BODY DIAMETER

OVERALL LENGTH

COLOR

DESCRIPTION:

This fuze, which is of the "all-ways" type, has a bakelite body, waisted to from two chamfered flanges, and is threaded at its lower end to permit it to be screwed into the fuze adapter. The fuze body houses a hollow cylinder, at the lower end of which is a detonator, located over a flash hole in the body of the fuze. The firing pin is positioned in the cylinder, and is split at its lower end to form a double striker. The striker is held away from the detonator by a light creep spring, which also is housed in the hollow cy-linder.

The upper end of the striker terminates in an enlarged head having a seating for a lead ball, which is held in position by the concave under-surface of a bakelite closure disc screwed into the top of the fuze bbody. Just below the striker head, the setm of the striker is drilled to receive a sfety pin, which extends through the fuze body and has an enlarged head housed in the waist of the fuze body. A short length of webbing tape, which is wound around the waist of the fuze body, is secured to the head of the safety pin. A lead sleeve, curved to fit into the waist of the fuze body, is secured over the free end of the webbing tape.

A bakelite safety cap is fitted over the fuze body and has a fabric drogue attached to it by adhesive tape.

OPERATION:

When the bomb is released from the Small Bomb Container, the safety cap of the fuze is drawn off by the action of air restistance on the fabric drogue. The lead sleeve on the webbing tape attached to the safety pin causes the free end of the tape to clear the waisted portion of the fuze body and to be caught in the air stream, thus withdrawing the safety pin. The fuze is now armed, with the lead ball and the striker held away from the detonator by the creep spring only.

On impact with the target, the momentum of the lead ball and the striker, overcom-ing the resistance of the creep spring, causes the striker point to pierce and fires the detonator. The flash from the detonator passes through the flash hole in the fuze body, initiating the action of the bomb.

If the bomb falls on its side, the ball, striker, and cylinder move sideways an an assembly, the ball riding up the curved surface of the closure disc, the cylinder riding up the curved surface of the body. The striker thus operates and fires the detonator.

Nose impact would causes the hollow cylinder to move down against the creep spring and impings the detonator on the striker.

REMARKS:

The No. 854 Mk I is identical to the No. 859 Mk I, except that the method of arming differs slightly. In the No. 854 Mk I, both the safety cap and safety pin are spring-load-ed. The safety cap holds the safety pin in place and is itself retained by an arming fork which engages the cap with the fuze body. The arming fork is withdrawn as the bomb is released from the Small Bomb Container, allowing the safety cap and safety pin to be ejected by their springs. The fuze is now armed. On impact with the target, its action is identical with that of the No. 859 Mk I fuze.

The No. 854 Mk I fuze has a long tubular burster screwed and cemented to its lower portion. This burster tube contains a powder pellet and about 2 oz. of gunpowder. It is approximately 5½" long and the tubular portion is 0.9" in diameter.

See page 98, "Smoke, 4 lb." for illustration of fuze in bomb.