Illuminating Mk 1

Length, inches

4.4

Diameter, inches

Total weight, ounces

Delay, seconds

Burning time, seconds

Candlepower

50,000

Description: This grenade is approximately the same size and shape as the fragmen-tation hand grenade. It consists of two sheet-steel cups joined together by a force fit, and sealed with Petman cement. The lower half contains the illuminating compound and a charge of black powder, which, when ignited by the fuze, blows the grenade apart and ignites the pyrotechic. The upper half contains the fuze assembly, which is similar in ap-pearance and in operation to that of the fragmentation hand grenade.

Operation: For hand launching, the grenade is held in one hand with the safety lever against the palm. The safety pin is removed with the other hand. When the grenade is thrown, the safety lever is released, and the striker, driven by its spring, forces the lever off, swings around its pivot, and strikes the primer. The flame from the primer ignites a delay train which burns through to the charge of black powder. The black-powder charge bursts the case and ignites the pyrotechnics.

For rifle launching, assemble the grenade in the Adapter M1, insert the safety lever into the arming clip, and force the grenade into place between the claws, so that the claws engage the raised portion of the grenade where the upper and lower halves are formed together. When the grenade is fired, set-back will cause the arming clip to come off the safety lever, and the striker will throw the lever off and hit the primer to activate the grenade.

Figure 226. Illuminating Grenade Mk 1