Description
Brass except for steel arming vanes, tightening pins and firing pin.
Tinned sheet steel booster housing.
Screwed into nose of bomb and tightened by a wrench that fits over the protruding pins.
The fuze body houses a spindle that has a firing pin at its lower end, and a threaded segment at the upper end that protrudes above the body. The vane assembly consisting of four black vanes attached to a brass hub screws onto this threaded portion. The central segment of the spindle is enlarged to form a shoulder for a rubber gasket located in a recess in the top of the fuze body. A brass washer threads into this hole and bears on the top of the gasket. The spindle is drilled to receive a brass shear wire 2.5 millimeters in diameter.
The primer is contained in a thin cylinder pressed into the lower fuze body against a dividing section. The section is pierced with a flash hole.
The delay element, consisting of a column of pressed brown powder, is carried in a brass piece which threads into the base of fuze body and aligns with the flash hole in the base of the dividing section.
The gaine threads into the base of the fuze immediately below the delay element. It has a relay pellet above a lead azide cone imbedded in cyclonite.
The booster, containing two cyclonite pellets, is housed in a light metal cylinder which is crimped onto a groove in the lower part of the fuze body just below the threads.
The section of the fuze body above the external threads is slightly larger than the A-2(a). This fuze is easily recognizable by two large spanner flats and two protruding steel pins.
Functioning
The safety fork is withdrawn allowing the vanes to rotate up the threaded spindle and fall clear. On impact with a solid target the shear wire is sheared and the firing pin is driven into the primer. The flash ignites the delay train which in turn fires the gaine.
Hazardous Components
Primer, delay, gaine, and booster. Relay incorporated in gaine.
Physical Data
Length, overall - 5.85 in (148.6 mm)
Width, overall - 2.43 in (61.7 mm)
See Also
Nose, A-2(a), Type 93 Instantaneous
Nose, A-8(b), 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)
