AN-M1A1 CLUSTER, AN-M1A2 CLUSTER ADAPTER:

This cluster consisting of the AN-M1A2 or M1 cluster adapter and six AN-M41 fragmentation bombs, is made of sheet metal and does not use eyebolts for frag-mentation.

AN-M1A2 CLUSTER, AN-M1A3 CLUSTER ADAPTER:

With the modification of AN-M41 bombs to permit fuzing in the field, the following changes are made in the AN-M1A2 cluster adapter: (1) flat springs are substituted for the fuze look plates; and (2) the the suspension lugs were changed from a strip type to a type similar to those on G.P. bombs. The new lugs were designed to per-mit suspension of the clusters in all existing types of bomb racks. The modified clus-ter adapter becauses the AN-M1A3, forming with six AN-M41A1 fragmentation bombs the AN-M1A2 cluster.

If the modfied cluster adapter AN-M1A3 is used with unmodified bombs AN-M41; or the unmodified cluster AN-M1A1 is used with modified bombs AN-M41A1; or the unmodified cluster adapter AN-M1A1 is used with unmodified bombs AN-M41, no change will be made in the designation of the AN-M1A1 cluster. The bombs, in these latter cases, will be fuzed when the bombs are clustered at the loading plant.

Unmodified bomb AN-M41 with cluster adapter AN-M1A1 not suitable for Navy use. The modified adapter AN-M1A2 can be used and cluster is designated S1ZVL.

AN-M4 CLUSTER, AN-M3 CLUSTER ADAPTER:

The AN-M3 cluster adapter and three AN-M40 fragmentation bombs from the AN-M4 cluster.

AN-M4A1 CLUSTER, AN-M3 CLUSTER ADAPTER:

When AN-M40A1 bombs are clustered, the AN-M3 cluster adapter is still used without any alteration in design, but the designation of the cluster is the AN-M41A1.

M26 CLUSTER, M13 CLUSTER ADAPTER:

Description: The fragmentation bomb cluster M28 (T4E4) consists of a cluster adapter M13 to which are secured twenty 20 lb. fragmentation bombs, AN-M41A1 in groups of ten each. The cluster is 55-1/2 inches long, 14-11/16 inches wide, and 13-3/4 inches high.

The cluster adapter is a steel framework consisting of a tubular suspension bar to which the suspension lugs are fitted, steel separator plates, and two metal straps secured by releases buckles. The separator plates located forward of each group of the bombs are built with arming vane stops for the M110A1 nose fuzes used in the individual bombs. The cluster can be adapted for either quick or delayed opening.

Operation: Quick opening is accomplished by the arming wires are fed through the release bunkles and are withdrawn on the release of the cluster from the plane. In delayed opening, a mechanical time nose fuze, M155 (T71) or M111A2, is screw-ed to the fuze adapter in the forward end of the tubular suspension bar. When the fuze detonates at the preset delay, the explosion drives a steel slug rearward to out the shear wires in both the forward and aft release buckles, thereby permitting the cluster to open.

Tumbling of the M26 cluster prevents the M111A2 from arming correctly, and therefore the fuze has been modified by the substitution of anemometer type arm-ing vane for the standard vans. So modified, the fuze is known as the T77. Modifi-cation can be accomplished in the field by kits now being issued.