Over-all length: 4 1/2 inches (without the arming spindle extension).

Over-all width: 2 6/16 inches.

Material of construction: Steel, except locking ring, safety collar, and spindle.

Position and method of fixing in bomb: The fuze is screwed into the tail of the bomb and tightened with a spanner wrench. A locking ring is then screwed down to secure the fuze.

Components of explosive train: The standard Japanese gaine is employed.

Fuzes likely to be found with: Navy nose fuze A-3 (a).

Delay times: Incorporated in the Navy gaine.

Threads: 2 9/64 inches in diameter; 4 threads per inch.

Description: The fuze body houses the safety collar, the striker, the arming spindle and the spring. Six spanner holes are found in both the body and the locking ring. The arming assembly consists of a long reach rod connecting the arming spindle and the vanes. The lower end of the spindle screws through the top of the fuze body and the safety collar into the striker.

Operation: On release from the plane, the vanes rotate, unscrewing the arming spindle from the striker. On impact, the striker moves against the action of the spring and pier-ces the primer in the gaine to set off the exploder system.

Remarks: This fuze has been removed only in the bomb listed above.

Variations of B-2 (a) have been found with:

1. Chromium plated body, brass locking ring, locating pins on same side;

2. Chromium plated body, chromium plated steel alloy locking ring, locating pins on same side;

3. Body and locking ring made of zinc plated steel alloy, locating pins on same side;

4. Body shoulders straight rather than sloping. Distance from top of shoulder to locking ring threads is 1 inch; two locating screw pins 180° apart; brass locking ring; body of unplated steel.

Figure 123 – B-2 (a) Bomb Fuze.