DATA:

BOMBS USED IN

FUNCTIONING

ARMED CONDITION

FUZES USED WITH

ARMING TIME

VANE SPANE

MAX. BODY DIAMETER

OVERALL LENGTH

MATERIAL

Steel, aluminum alloy, and brass; the brass parts are tin plated and some steel parts are cadmium plated. The bottle shaped tail support is cast aluminum alloy.

GENERAL:

This fuze is similar in design and operation to the Mk 223, and is almost identical in external appearance. It is distinguished from the Mk 223 in that it has red vanes. The AN-Mk 228 has the following distinctive internal features: It has two separate explosive trains and a delay of .08 second; two firing pin extensions are fitted on the lower end of the hammer carrier. Two delay elements and two delay firing pins are housed in the delay carrier. The detonator carrier has two detonators, and the shaft extension nuts contain two auxiliary booster lead-ins which are aligned with two booster lead-ins in the fuze body. One firing pin is slightly longer than the other, so the two firing are not initiated simultaneously.

OPERATION:

As the arming wire is pulled, the vanes rotate and turn the arming vane shaft, rotat-ing the cap and revolving the pinion around the inner gears. Arming of the fuze than continues as in the AN-Mk 219, see page 235. The AN-Mk 228 has an added detent in the delay carrier which locks when the firing train is lined up. On impact, a shear wire through the supporting collar and spindle is cut, as the firing pin extensions force the firing pins into the primers.

REMARKS:

Delay elements consists of a primer, delay charge of black powder, and special deto-nator of lead azide; detonator consists of lead azide; auxiliary booster lead-ins, and booster consists of tetryl.