One side, 2660.
Other side –

Position and method of fixing in bomb: Screwed clockwise into nose. There are spanner wrench flats on side of body. No anti-withdrawal or locking device is used.

Components of explosive train: Employs standard Navy gaine or magazine.

Fuzes likely to be found with: Probably B-3 (b).

Delay times: Incorporated in Navy gaine.

Threads: 10 threads per inch; diameter, 1 7/8 inches.

Description: The fuze consists of three main parts: the body, the striker spindle, and the arming vane assembly. The striker spindle is located in the fuze body by means of a locating screw and a shear wire which prevent the spindle from rotating or moving for-ward until impact. The upper portion of the spindle is threaded while a steel firing pin is screwed into the lower end. The arming vane assembly consists of a nose cap, arming vanes, and arming sleeve. The arming sleeve internally threaded, screws onto the spindle and its length of travel is limited by a stop screw threaded into the top of the spindle. To this sleeve, the nose cap and arming vanes are attached by four short screws. The lo-wer end of the fuze body is internally threaded to take the standard Japanese gaine or magazine.

A heavy wire eyelet is attached to the side of the fuze body and serves as a guide for the starting wire. The starting wire is soldered to the nose cap in two places and gives an initial turn to the arming assembly when the bomb is dropped. A safety fork fits into the upper portion of the fuze body, one prong of which extends up through eyelets of arming vane assembly to prevent premature vane rotation.

Operation: On release of bomb, the arming wire pulls the starting wire through the eye-let, breaking it loose at the soldered and simultaneously imparting an initial rotation to the arming vane assembly. In seven revolutions, the arming sleeve rises up the stirker spindle to lock against the stop screw and arm the fuze. On impact, the entire assembly (vanes, nose cap, sleeve and spindle) is driven inward, shearing the shear wire, and the firing pin pierces the primer.

Remarks: This fuze is similar to the A-3 (a) with the following exceptions: (a) the ma-roon lacquered lower fuze body is 1 7/16 inches longer than that of the A-3 (a); (b) the striker spindle of the new fuze is longer than that of the A-3 (a) to match the elongated lower fuze body; (c) the vanes have a span of 4 3/4 inches as compared to the 3 1/2 inch vane span of the A-3 (a).

The threads on the arming spindle are 12 threads per inch.

Figure 118 – A-3 (d) Bomb Fuze.