USNBD, Rockets and Fuzes; 7.2" Projector Charge Ammo

U.S.N.B.D. - ROCKETS AND FUZES

ROCKET HEADS

		U.S. NAVY

OVERALL LENGTH	38.6 in.	7.2" PROJECTOR CHARGE AMMO
HEAD LENGTH	19.0 in.
HEAD DIAMETER	7.2 in.
HEAD WEIGHT	17.9 lbs.
FILLER WEIGHT (TNT)	31.1 lbs.
WALL THICKNESS	0.2 in.
TAIL TUBE DIAMETER	1.75 in.	(This is not a rocket, but a pro-
TAIL LENGTH	16.5 in.	jectile; it is included here be-
TAIL WIDTH	7.0 in.	cause of its similarity to the
TAIL WEIGHT	9.3 lbs.	Mousetrap)

TARGET:

For use by patrol vessels against submarines.

FUZING:

Nose: The Mk 136 and the Mk 140 are replaced by the Mk 158.

BODY CONSTRUCTION:

The projectile consists of a flat nosed head with a concial flat tail fairing and parallel sides. The adapter and fuze thread into the nose. The motor unit consists of a smoke-less powder cartridge with primer which is lodged forward in the tail tube, the tube fit-ting over a firing post. The primer is detonated by electrical contacts in the post, re-sulting in firing the cartridge which propels the charge of the projector. This projector charge is adapted for use on the projectors Mks 10 & 11.

TAIL CONSTRUCTION:

A steel tube attached to head by a threaded joint. Tail fins have a 10 degree twist and are attached with a drum support in order to give a slow rotation and stabilized trajectory.

REMARKS:

(1) When Tropex is used, the weight is increased by approximately 2.5 lbs.

(2) Formerly known as the Hedgehog.

(3) The above data is based on the 7.2" head Mk 4A and the 1.75" P.C. tail Mk 4A. These are being replaced by 7.2" head Mk 4 Mod 0 and the 1.75" P.C. tail Mk 6 Mod 0.