Description
Natural steel color except for brass nose cap.
Steel except for brass nose cap and arming sleeve.
May be found with Fuze B-2(a), slightly modified. This fuze is an elongated A-3(a) and its operation is identical.
The fuze consists of three main parts: the body, striker spindle and arming vane assembly.
The striker spindle is housed in the fuze body and is held in position by a locating screw and a shear wire. The spindle is made in three sections. The upper section, which is externally threaded to take the arming sleeve, is internally threaded in the top to take the stop screw and internally threaded in the bottom to take the middle section of the spindle. The lower section of the striker spindle is internally threaded to take the middle section. The arming vanes and nose cap are attached to the arming sleeve by four screws.
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.
Functioning
On release of bomb, the arming wire pulls the starting wire through the eyelet, breaking it loose at the soldered points and simultaneously imparting an initial rotation to the arming vane assembly. In seven revolutions, the arming sleeve rises up the striker 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.
Hazardous Components
Navy gaine.
Physical Data
Length, overall - 10 in (254 mm)
Width, overall - 2 in (50.8 mm)
Vane span - 3.5 in (88.9 mm)
See Also
Nose, A-3(a), Type 97 Mk 2 Model 2
Tail, B-2(a), for Type 99 No. 25 Ordinary
Source(s)
OP 1667, Japanese Explosive Ordnance, Volume 1 (1946)
TM-E9-1984, Enemy Bombs and Fuzes, Section VII, Japanese Fuzes (1942)
