Over-all length

Diameter

Pressure to actuate

The igniter is screwed into the nose of obso-lete 12- or 15-cm shells for use as improvi-sed mines. A tubular picket is then fitted over the top of the igniter, the grub screw making a bayonet joint.

The notched copper tube is fitted with the boss piece and the striker guide piece. Run-ning through this assembly is a striker, which is held against the spring by the nut. The locking pin on the underside of the nut seats in the top of the boss piece to prevent the nut from working loose and releasing the striker.

The union, joining the cap holder to the stri-ker guide piece, carries the safety shutter. The safety shutter cannot be withdrawn if the striker has accidentally been released, is the striker had would have entered in the hole. The detonator holder containing the detonator is screwed onto the open end of the cap holder.

The seal is broken and the safety shutter is withdrawn by means of a cord attached to the ring. A thrust applied to the top of the picket will rupture the copper tube at the circumferential notch and shear the striker at the neck. This releases the spring-loaded striker head to fire the cap, and then, through the 0.75 sec. delay pellet and the powder train, the detonator.

Figure 280 – Rupture Igniter