Motor Mk 5 and Head Mk 7

OVERALL LENGTH

HEAD WIDTH

HEAD LENGTH

MOTOR LENGTH

PROPELLANT

PROPELLANT LENGTH

FILLER

FILLER WEIGHT (FS)

PROPELLANT WEIGHT

TOTAL WEIGHT

RANGE (approx.)

FUZING, Nose:

COLOR (head)

COLOR (motor)

Olive drab with nomenclature stencilled in yellow

USE:

Laying smoke screens or disseminating chemical agents among enemy troops.

LAUNCHER:

This rocket is fired from a 24-rail demountable, variable-elevation launcher carried in a 2½ ton truck. The salvo is fired in 2½ seconds, and the launcher can be reloaded in 1-1/2 minutes.

GENERAL:

These two rockets are identical, and are under production by the Army as the 7.2" T21 rocket, through the rocket is of Navy design and takes a Navy fuze. The only es-sential difference between the rockets as used by the Army and Navy is in the propel-lant, as is mentioned above.

CONSTRUCTION:

The head consists of the container, adapter, burster tube, burster charge, chemical charge, shipping plug, and connector. The container is a bulb-shaped steel tube open at both ends. The adapter fits inside the flange on the forward end of the container and is brazed thereto. The wide, forward end of the adapter is internally threaded to seat the fuze. The burster tube, made of steel, fits inside the adapter and extends downward into the container. The tube and adapter are held together by a press fit and sealed with white lead paste. The rear end of the tube is closed.

MOTOR:

The motor is a steel tube, the forward end of which is externally threaded to screw into the connector of the head. The venturi tube, or nozzle is slipped down thru the large, open end of the motor body, and the end is welded to the inner edge of the motor-body rim.

TAIL ASSEMBLY:

The tail assembly consists of two tail vanes, a front and four fins. Each vane is made of steel and is shaped roughly like a W. The two shrouds fit over the vanes. The terminals for the igniter lead wires are attached to the inner surfaces of the two shrouds. The steel fins are welded to the outside of the motor body just forward of the taper, with the aft end cut out to fit over the shrouds.

PROPELLANT:

7.2" CMR-N: As produced for the Navy, the propellant consists of a single grain of solventless extruded ballistite with an outer diameter of 2.5" and inner diameter of 1.0". This is the Mk 11 grain.

7.2" T21 Army Chemical Rocket: When used by the Army, howerver, the propellant used consists of four sticks of ballistite, with a 1.0" axial hole, placed ent to end with a washer between each. The sticks are 3-ridged, and each has eight sets of three holes radially through it. Overall length of the four sticks is 20.5".

REMARKS:

This rocket is in current production by the Army as the "7.2" T21 Rocket".