Description
Natural brass color.
Brass except steel spring and steel firing pin.
Nose fuze screwed in by hand and tightened by spanner wrench.
Components of explosive train: Primer flash cap ignites a short delay train, or passes through the selector to give instantaneous action by igniting a relay which sets off the gaine.
Fuze likely to be found with Tail, B-1(a), Type 12 Year.
The upper body portion houses the striker and arming spindle while the lower body portion contains the selector mechanism for instantaneous or short delay. A shear wire and spring hold the arming spindle after the vanes fall away. A U-shaped safety wire fits over the vanes into the holes. A selector screw is fitted in the fuze body and cannot be changed while the fuze is fitted within the bomb. A stop stud on the body and one on the vane cap prevent the arming vane assembly from jamming too tightly. The Regular Army gaine is fitted to the fuze.
If the fuze is found with the arming spindle depressed, the striker is probably imbedded in the primer and a slight movement may free it, and the spring will force the striker back. This friction may be sufficient to set off the primer, thereby igniting the exploder system. Could be used in 15-kilogram antipersonnel, 50-kilogram incendiary, and 50-kilogram gas bombs.
A-2(a) has been found with a short black power gaine extending only 11/32 inch below the fuze body.
Functioning
The arming wire is withdrawn from the vanes upon release of the bomb and after 10 revolutions, the vanes fall free. On Impact, the wire is sheared and the striker Is forced inward against the action of the creep spring. If the selector screw is set for instantaneous action, the flash from the primer passes directly through a hole In the selector screw to fire a relay which fires the gaine. If set for delay action, the flash from the primer ignites the delay in the selector screw and this delay fires a relay which in turn fires the gaine.
Hazardous Components
No information about hazardous components.
Physical Data
Length, overall - 2.75 in (70 mm)
Width - 1.65 in (42 mm)
See Also
Nose, A-8(a), Type 4 Two Second Delay
Source(s)
OP 1667, Japanese Explosive Ordnance, Volume 1 (1946)
TM-E9-1984, Enemy Bombs and Fuzes, Section VII, Japanese Fuzes (1942)
