Material of construction: Brass except for an aluminum striker body and steel firing pin and spring.

Position and method of fixing in bomb: The fuze is screwed into the tail fuze pocket and tightened with a spanner wrench.

Components of explosive trains: Incorporated in the Navy gaine.

Fuzes likely to be found with: A-3 (g), B-10 (a).

Delay times: Incorporated in the Navy gaine.

Threads: 12 threads per inch, RH, 1 15/16 inches in diameter.

Description: The fuze body has at its upper end a dome-shaped cap which has a curved inner surface. The cap is pierced by a central hole through which a stud on the arming fork fits to engage a recess in the top of the striker extension. The cap is held in place by a grub screw. Two holes 180° apart are drilled longitudinally in the fuze body to ac-commodate an arming fork. Two holes are drilled through the body wall along the axis of one of the longitudinal holes. The upper hole appears to be for inspection purposes. The lower hole contains a spring-loaded arming detent. A screw threads into the body just below this hole and prevents the detent from flying out of the body after it has been re-leased by the arming fork. Two air vents 180° apart pierce the lower portion of the fuze body. A groove in the bottom of the fuze body contains a locking spring which serves to secure the fuze firmly in its pocket.

The striker assembly consists of a striker extension, striker, and a spring. The striker ex-tension is an egg-shaped brass knob having a cylindrical lower shaft, at the end of which is machined a small ball. The striker has a wide head which is recessed in its center to take the ball of the striker extension. There is a deep annular groove in the side of the striker into which is fitted a spring-loaded arming detent held in position by the arming fork. A spring holds the striker away from the primer after the detent has been released.

Operation: When the pilot of the bomb pulls the handle of the tail fuze arming mecha-nism, the arming fork is withdrawn far enough to allow the spring-loaded detent to move outward, disengaging the groove in the striker. The fuze is now armed. The striker is held away from the primer by the spring. On direct impact the weight of the striker extension forces the striker down compressing the spring and hitting the primer.

If the impact is not direct, the striker extension is cammed to the side against the cur-ved dome of the closing cap. This action forces the striker down against the spring, thereby firing the primer.

Figure 129 – B-9 (a) Bomb Fuze.