British Bomb, 250 lb DC, Mk 11 and 11*
The body is a welded cylindrical case closed at each end by a cover which is welded on. The central primer tube is welded into an opening in the rear cover, and extends approximately half way through the body. Equispaced around the rear cover are three lugs, each drilled and tapped to receive a stud used for securing the tail to the depth charge. Two filling holes, each closed by a bung, are provided in the rear cover. The front cover is dished inward to prevent ricochet.
The Tail Assembly Mk III is simply a cylindrical drum open at both ends.
A strengthening ring is welded to the front end and provided with three equi-spaced brackets, weakly riveted on, which fit over the studs in the corresponding lugs on the rear end cover of the body. The tail is strengthened by six circumferential corrugations. The tail breaks off on impact with water. The front of the tail has one large port for the fuze-setting control link, and two small ports to give access to pistol and valve unit when fitting the fuze-setting control link.
The Tail Mk IV is designed with arming vanes and a reach rod to arm Pistols Mks XIX and XX, which are of the air-arming type and are replacing the Tail Hydrostatic Pistols Mks XIV and XVI. This tail is constructed with a three-segment cone, to which are riveted three fins supporting the three-segment cylindrical strut. Three hand clearance holes are equispaced around the forward end of the cone.
The Bomb Mk XI has a single lug welded to the case at the center of gravity for British aircraft. The Bomb Mk XI* has dual lugs welded to its case for suspension from US aircraft.