M108 (Nose Mechanical Impact) (Obsolete)

Bombs

Functioning

Armed condition

Fuzes used with

Arming time

Body diameter, inches

Over-all lenght, inches

Material

Brass fuze body with cadmium- or zinc-plated steel striker

General: This fuze is not threaded into the nose bomb nose, but is pushed down and held there by two spring-loaded retaining balls which protrude from the side of the fuze. The fuze requires an adapter ring having an annular groove to receive the retaining balls.

Operation: When the arming wire is withdrawn from the arming pin as the bomb is dropped, the arming pin is ejected from the fuze by the action of the arming-pin spring. The safety block holder then falls free of the fuze, and the safety block is ejected clear of the fuze and striker by its spring. On impact, the striker is driven into the fuze body, cutting the shear wire and impinging on the primer, setting off the upper detonator on the primer, setting off the upper detonator and the lower detonator successively.

Early design: The early M108 did not have a safety block inserted between the stri-ker head and the fuze body, and was quit dangerous, as a drop of only a few inches on a hard surface was enough to activate the fuze. The M108 Modified is shipped with the safety block as shown in figure 333.

Remarks: This fuze was designed for use in the 100-pound Incendiary Bomb M47. It is being replaced by the AN-M126A1 in all bombs except the Target Indentification Bomb M75.

Figure 333. Nose Fuze M108