4-pound Incendiary AN-M54 Series (Obsolete)

Over-all length, inches

Body length, inches

Body diameter, inches

Tail length, inches

Tail width, inches

Filling

Weight of filling, pounds

Total weight, pounds

Charge/weight ratio

40%

Construction: The bomb body is a steel cylinder having a hexagonal nose plug. The fuze is installed in the tail plug assembly. There are three vent holes below the primer cap assembly, to assist in initial burning. There is a hexagonal hollow sheet-metal tail.

Suspension

AN-M8

M5

100#

27 AN-M54

7 AN-M54XA1

M9

M6

500#

102 AN-M54

26 AN-M54XA1

Operation: The spring-loaded safety plunger is depressed by the adjacent bomb; upon release from the cluster, it jumps out, leaving the firing pin riding on a creep spring. On impact, the firing pin overcomes its creep spring and strikes the primer, igniting the thermate, which melts the steel body and releases molten iron.

Remarks: AN-M54A is the same as AN-M54, except that next to the hexagonal nose plug a small portion of the thermate charge is replaced by a steel capsule containing 170 grains of black powder, which explodes and scatters the molten iron after the bomb has burned about one minute. It is limited standard for the Army, obsolte for the Navy.

AN-M54XA1 is the same as the AN-M54, except that inside the hexagonal nose plug there is a steel cylinder containing a tetryl high-explosive charge with a delay fuse and a detonator. A thin spacer of magnesium is between the thermate and the fuse opening of the explosive cylinder. After one minute of burning, the fuse is ignited, exploding the tetrly. These bombs are no longer being procured for naval service, and should not be used except when Incendiary Bombs AN-M50A1 or AN-M69 are not available. It is limited standard for the Army, obsolete for the Navy.

Figure 305. 4-pound Incendiary Bomb AN-M54