Description
The Type 97 Rail Initiator is a Japanese Navy mechanical impact tail fuze. It is used in the 31 kg practice bomb. The fuze is brass except for the steel striker and creep spring.
The upper portion of the body acts as a guide for the arming spindle. The lower portion of the body contains the light spring. The firing pin is screwed into the end of the striker. The lower portion of the fuze has a combination spanner ring and detonator cup screwed to it. Around the striker, four air vents are drilled. Two vents are also located on the striker collar. These vents allow the striker to move against the primer on impact without any cushion effect caused by the air in the striker channel. The arming vane assembly has eight vanes.
Functioning
On release from the aircraft, a U shaped safety fork is withdrawn from the two holes in the arming spindle. The vanes rotate twelve times and fall free, leaving the striker held back by the light spring. The arming spindle is prevented from rotating by a small locating pin which fits in a keyway in the lower portion of the fuze body. On impact, inertia causes the striker to move against the spring and to pierce the primer.
Hazardous Components
No information about hazardous components.
Physical Data
Length, overall - 3.6 in, 91.4 mm
Width, overall - 1.25 in, 31.8 mm
Vane span - 2.3 in, 58.4 mm
See Also
Nothing else to see.
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)
