7.2-inch C.W.R.-N. and M25, M27, and T24

Over-all length, inches

Head width, inches

Head length, inches

Motor length, inches

Propellant (ballistite)

Filler

Filler (F.S.), pounds

Total weight, pounds

Range, yards

Fuzing

Nose: Mk 147 or Mk 147 Mod 1

General: This rocket is fired from a 24-rail demountible, variable-elevation launcher carried in a 2½-ton truck. The salvo is fired in 2½ seconds, and the launcher can be re-loaded in 1½ minutes.

These rockets of Navy design are under production by the Army. The only essential difference between the rockets as used by the Army and the Navy is in the propellant.

Head: 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 whitel-lead paste. The rear end of the tube is closed.

Motor: The motor is a steel tube, with the forward end externally threaded to screw into the connector of the head. The nozzle is slipped down through the open end of the motor body, and the end is welded to the inner edge of the motor-body rim.

Tail: The tail assembly has four tail vanes spot-welded in pairs to the motor tube and spot-welded to the rear shroud. The forward shroud is riveted to the vanes but insulated from them. Four large fins are welded to the motor tube, pass over the forward shroud. The lead wires are connected to the two shrouds which serve as contacts.

Propellant: As produced for the Navy, the propellant consists of a single grain of sol-ventless extruded ballistite with an outer diameter of 2.5 inches and an inner diameter of 1.0 inch. This is the Grain Mk 11.

In the Army Chemical Rocket M25, the propellant consists of four sticks of ballistite, with a one-inch axial hole, placed end to end with separating washers between the sticks. The sticks are three-ridged, and each has eight sets of holes radially through it. The over-all length of the sticks is 20.5 inches.

Remarks: The Army Rocket M27 is structurally the same as the Navy rocket, but is filled with C/K gas. Its total weight is 51.8 pounds.

A head similar to the Mk 7 but loaded with 22 pounds of TNT and equipped with a booster instead of a burster tube is known as the Mk 9. It is a demolition head, using the Fuze Mk 137 and the 3.25-inch Motor Mk 5. This combination may be used to lay down a barrage from the same launchers as the C.W.R.-N.

When the Head Mk 9 is fuzed with the Fuze Mk 147, it is known as the Round T24. Its total weight is 51.8 pounds.

Figure 138. 7.2-inch C.W.R.-N. and M25 and M27