Description
The fuze body houses the striker, the spring, the safety collar, and the arming spindle. The upper end of the body is internally threaded, right-hand, to receive the bushing which secures the safety collar in position. The arming assembly consists of the vanes and a long reach rod which slide-fits over the arming spindle. A locking ring screws down over a shoulder of the body to secure the fuze in the bomb.
The safety collar and the top of the striker are internally threaded, left-hand, to receive the arming spindle. The collar rests on a shoulder of the fuze body and prevents the striker from moving downward when fuze is unarmed. The striker and safety collar are prevented from rotating by the locating screw and locating pin respectively.
The arming assembly is similar to the B-2(a) except that the arming vane span of the B-2(b) is only 3-15/16 inches as compared to the 4-11/16 inches span of the vanes used with the B-2 (a).
A small model of the B-2(b) has been recovered in a 250-kg. Ordinary bomb, having a thread diameter of 2-9/64 inches.
Functioning
On release from the plane, the arming vanes rotate, unscrewing the arming spindle from the striker. On impact the striker moves against the spring and pierces the primer in the gaine.
Hazardous Components
Primer, gun powder delay, and picric detonator are all incorporated In the large Japanese gaine filled with picric acid as the booster charge.
Physical Data
Length, overall - 6 in, 152.4 mm (approx)
Width, overall - 3 in, 76.2 mm (with locking ring)
Vane span - 3.94 in, 100.1 mm
See Also
Tail, B-2(a), for Type 99 No. 25 Ordinary
Source(s)
OP 1667, Japanese Explosive Ordnance, Volume 1 (1946)
USNBD - Japanese Bombs & Fuzes (1944)
TM-E9-1984, Enemy Bombs and Fuzes, Section VII, Japanese Fuzes (1942)
