Fragmentation clusters and cluster adapters

Cluster AN-M1A1, Cluster Adapter AN-M1A2: This cluster,consisting of the Cluster Adapter AN-M1A2 or M1 and six Fragmentation Bombs AN-M41 is made of sheet metal and does not use eyebolts for suspension.

Cluster AN-M1A2, Cluster Adapter AN-M1A3: With the modification of Fragmenta-tion Bombs AN-M41 to permit fuzing in the field the following changes are made in the Cluster Adapter AN-M1A2: (1) flat springs are substituted for the fuze lock paltes; and (2) the suspension lugs are changed from a strip type to a type similar to those on G.P. bombs. The new lugs were designed to permit suspension of the clusers in all existing ty-pes of bomb racks. The modified cluster adapter becomes the AN-M1A3, forming, with six Fragmentation Bombs AN-M41A1, the Cluster AN-M1A2.

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

The unmodified Fragmentation Bomb AN-M41 with Cluster Adapter AN-M1A1 is not suitable for Navy use. The modfied Adapter AN-M1A2 can be used, and the cluster is de-signed S1ZVL.

Cluster AN-M4, Cluster Adapter AN-M3: The Cluster Adapter AN-M3 and three Fragmentation Bombs AN-M40 form the Cluster AN-M4.

Cluster AN-M4A1, Cluster Adapter AN-M3: When Para.-Frag. Bombs AN-M40A1 are clustered, the Cluster Adapter AN-M3 is still used without any alteration in design, but the designation of the cluster is AN-M4A1.

Cluster M26, Cluster Adapter M13: The Fragmentation Bomb Cluster M26 consists of a Cluster Adapter M13 to which are secured twenty 20-pound Fragmentation Bombs AN-M41A1, in two groups of ten. See figure 264, page 361. The cluster is 53½ inches long, 14-11/16 inches wide, and 13¾ inches high. The cluster adapter is a steel frame-work consisting of a tubular suspension bar to which the suspension lugs are fitted, steel separator plates, and two metal straps secured by release buckles. The separator plates located before each group of the bombs are built with arming vane stops for the Nose Fuzes M110A1 used in the individual bombs. The cluster can be adapted for either quick or delayed opening.

Quick opening is accomplished by the arming wires, which are fed through the release buckles and are withdrawn on the release of the cluster from the plane. In delayed open-ing, a Mechanical Time Nose Fuze M155 (T71) or M111A2 is screwed 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 cut the shear wires in both the for-ward and the after release buckles, thereby permitting the cluster to open.

Tumbling of the Cluster M26 prevents the Nose Fuze M111A2 from arming correctly, and therefore the fuze has been modified by the substituion of an anemometer-type arming vane for the standard vane. So modified, the fuze is known as the T77. Modifica-tion can be accomplished in the field by kits now being issued.