Over-all length (with gaine): 3 15/16 inches.

Maximum diameter: 1 5/8 inches.

Threaded length: 1/4 inch.

Number of threads: 6.

Construction: The fuze consists of a brass vane cap and vanes, black steel two-piece body, brass keyed striker, steel creep spring, brass selector delay, container, and a brass gaine. Either an instantaneous or a short delay setting may be made by inserting a screw driver into the slotted end of the cylinder and rotating the cylinder in the selector delay container so the instantaneous flash channel is either open for instantaneous burst, or closed for a short delay burst. The delay powder train is ignited in either case. A set-back pin prevents the vanes from rotating until the projectile is fired.

Operation: The arming fork is removed when the finned bangalore is ready to be fired. When it is fired, the set-back forces the set-back pin down, allowing the vanes to rotate up and off, leaving the striker exposed and supported only by its creep spring. On im-pact, the striker compresses the creep spring and is driven into the primer. The flash from the primer ignites the delay train and, if the instantaneous channel is open, also flashes directly into the gaine.

Figure 327 – Finned Bangalore Torpedo Fuze.