7.0-inch 100-pound Depth Bomb Mk 52650-pound Depth Mk 38 (TNT) and Mk 49 (Torpex) (Obsolete)
U.S. EXPLOSIVE ORDNANCE
PART 6 - BOMBS AND BOMB FUZES
Chapter 17 - EXPLOSIVE BOMBS
Section 4 - NAVY "MK" SERIES

650-pound Depth Mk 29 (Obsolete) and Mk 37 (Obsolete)

  Mk 29 Mk 37

Over-all length, inches

70.0 63.0

Body length, inches

41.0 41.0

Body diameter, inches

17.7 17.7

Wall thickness, inches

0.12 0.12

Tail length, inches

36 29

Tail width, inches

17.7 17.7

Filling

TNT TNT

Weight of filling

464# 464#

Total weight

657# 659#

Charge/weight ratio

70% 70%

Fuzing

Nose - AN-M103 (Instantaneous); AN-M103A1; AN-Mk 219 (Instantaneous); Mk 221; Mk 239.

Athwartship - AN-Mk 224 or AN-Mk 234.

Tail - Mk 229, Mk 229 Mod 3; AN-Mk 230, Mods.

Body construction: These bombs are manufactured with a hemispherical nose rein-forced with a steel disc. The suspension lugs are reinforced with a steel strip. A flat-nose attachment, in the shape of a bucket and fitting down under the nose of the bomb, can be used to improve underwater trajectory. The vacant spaces are then filled with plaster of paris. These attachments increase the weight by 72 pounds.

Suspension: Horizontal suspension is provided by the usual two suspension lugs, with threaded holes on each side 90° removed to reveice trunnion lugs for the displacement gear of dive bombers.

Color and markings: The bombs are painted olive drab or grey over all, with an 11-inch yellow disc between the two suspension lugs. They may be light grey over all.

Tail construction: Four sheet-steel vanes are welded to the tail cone, which is se-cured to the body by a locking nut screwing onto the rear of the body. An annular strut is used around the rear of the vanes. The tail of the Mk 37 was shortened by seven in-ches so that the Tail Fuze Mk 229 could arm more readily. Otherwise, the tail is similar to that of the Mk 29.

Remarks: AN-Mk 219 will not arm under 2,500 feet of altitude if the flat-nose attach-ment is used.

Use Adapter Ring Mk 219 and insert an additional auxiliary booster when using AN-Mk 219.

AN-M103 or AN-M103A1 will not arm with the flat-nose attachment, unless special arming vanes are used.

An extender is supplied with each bomb to permit installation of the Hydrostatic Fuze AN-Mk 224 or AN-Mk 234 in the longer athwartships tube.

The Mk 29 is converted to the Mk 37 by replacing the tail.

Because of numerous instances in water crash landings where depth bombs fuzed with the Athwartship Fuze AN-Mk 224 or AN-Mk 234 exploded, these two fuzes have been suspended from use. As a consequence, the Depth Bombs Mk 29 and Mk 37 may be used only if a nose impact fuze is installed.

Figure 271. 650-pound Depth Bombs Mk 29 and Mk 37

7.0-inch 100-pound Depth Bomb Mk 52650-pound Depth Mk 38 (TNT) and Mk 49 (Torpex) (Obsolete)