Description
Natural brass.
Brass except for light metal striker-primer assembly.
The fuze is screwed into the nose fuze pocket and is usually secured in place by a grub screw.
The primer is housed in the fuze body. The remainder of the explosive train is contained in the gaine.
The fuze body is of one piece brass construction. The upper portion of the body is threaded externally to receive the arming vanes. The lower portion is threaded internally to accommodate an Army type gaine and threaded externally to fit a fuze pocket.
The fuze body contains the striker-primer assembly. This consists of a light metal striker primer housing, striker, primer, spring, light metal cup, washer, and copper shear wire. The striker is secured to a disk which rests on the shoulder of the tubular striker-primer housing. The metal cup fits inside of the housing and its edges bear against the striker disk. The copper shear wire holds the entire assembly in position. The primer is in the base of the housing and is held there by a winged washer which fits into the slots in the side of the housing. A spring separates the washer and the striker disk.
A bayonet joint on the inside of the fuze body accommodates the wings of the washer in assembling the fuze. After being inserted, the striker primer housing is rotated 90° before it is secured in place.
The striker primer assembly in this fuze is an exact copy of the Remondy mechanism used in French fuzes.
Functioning
As the bomb is dropped, the safety pin is pulled allowing the arming vanes to rotate. After seven turns they fall completely off, exposing the thin metal head of the striker-primer assembly, which is flush with the top of the fuze body. On impact, the pressure of the earth against the striker body head drives the entire assembly to the rear, shearing the shear wire, except for the primer, which, being free to move forward against the creep spring by its own inertia, stabs itself against the striker and initiates the explosive train.
If the striker body is flush with the top of the fuze body, the fuze is relatively safe to handle. If the striker body Is driven down more than 1/8 inch, the fuze may be In a very sensitive condition.
Hazardous Components
Mercury fulminate primer, black powder relay, gaine.
Physical Data
Length, overall - 2.6 in (64 mm)
Width, overall - 1.56 in (40 mm)
Width, vanes - 3.38 in (86 mm)
See Also
Bomb, 50 kg Chemical, Type 100
Bomb, 50 kg Incendiary, Type 100
Source(s)
OP 1667, Japanese Explosive Ordnance, Volume 1 (1946)
TM-E9-1984, Enemy Bombs and Fuzes, Section VII, Japanese Fuzes (1942)
