Tag Archive for 'type 10'

Rocket Launcher and Rocket Motor Model 10

Rocket Launcher and Rocket Motor Model 10

This is a device designed to propel the 60 kg. (132 lbs.) aircraft bomb out of an inclined trough.

The launcher is constructed of wood and metal with legs made of iron pipe. The rear is attached by a pin to a base plate with six wedge cut ground pins. The launcher channel is a right angle trough about twenty feet long with a motor and bomb positioner made of 1/8-inch pierced sheet metal. This is “V” shaped, (The motor and bomb positioner is not shown in the schematic sketch above.) slightly over four feet long, and hinged at three points on the lower right side of the launcher. Elevation is controlled by cables run from the base plate to the legs, and between the legs.

The rocket motor resembles a blunt, short-bodied bomb. The propellant container is a cylinder with a cap welded on the front and a tail assembly and venturi tube secured on the rear. The propellant which weighs 12.94 pounds consists of three cylindrical sticks tied in a yellow silk bag. It is ignited by an igniter pad and an igniter fuze in the forward part of the motor by means of wires leading to a small hand blasting machine. When fired the motor propels the bomb from the launcher and then drops off. Ranges up to 1,300 yards are claimed by the Japanese for this device, but it is felt that little, if any, accuracy may be expected. It is evidently designed to deliver fire on beachheads and other similar wide targets at fairly short ranges.


Length of launcher (overall)       19 ft., 10 ins.
Width at leg shoes8 ft., 5.5 ins.
Height at 30° range setting11 ft.
Length of leg12 ft., 4 ins.
Diameter of leg1.75 ins.
Width outside of trough at base10 ins.
Width outside of trough at front7.5 ins.
Width inside of trough at base8.5 ins.
Width inside of trough at front6 ins.
Length of cable from baseplate to leg20 ft., 3 ins.
Length of motor and bomb positioner (overall)4 ft., 3 ins.
Length of motor (overall)33 ins.
Length of propellant cylinder11.5 ins.
Diameter of propellant cylinder (outside)7.44 ins.
Diameter of venturi tube (outside)1.5 ins.
Length of tail fin11.75 ins.
Width of tail fin3.625 ins.
Width of tail, fin to fin11.875 ins.

Japanese: p. 351 (April 1, 1945)

120 mm, 45 Caliber, Naval Dual Purpose Gun, Type 10

120 mm, 45 Caliber, Naval Dual Purpose Gun, Type 10 (Japanese WWII)

The Japanese Type 10 dual purpose gun has a 45-caliber barrel of monobloc construction with uniform right hand rifling. A long, narrow rectangular projection on the bottom of the barrel slides in a groove in the sleeve type cradle, preventing the barrel from rotating. The bearing surface for recoil being the machined barrel surface. The cradle is mounted on a pedestal mount which permits a traverse of 360 degrees.

The elevating handwheel is on the right side of the mount, while the traversing handwheel is on the left. An auxiliary handwheel on the left side permits the piece to be elevated and traversed by the gunner. To compensate for muzzle preponderance, a spring pusher type equilibrator is used. The gun is well balanced, and exceptionally easy to elevate. The recoil mechanism is a hydrospring type, the two outside cylinders housing the counterrecoil springs, and the center cylinder the hydraulic mechanism. A semiautomatic horizontal sliding breechblock is used.

The mount is of riveted construction.


Caliber       120 mm (4.7 ins.)
Weight (firing position) 6,500 lbs.
Length (gun and mount) 19 ft., 6 1/2 ins.
Length (firing position)
Height (gun and mount) 7 ft., 8 1/2 ins.
Height (firing position)
Width (gun and mount) 7 ft., 1 in.
Length of tube 17 ft., 1 1/2 ins.
Length of rifling 14 ft., 9 1/2 ins.
Length, of chamber 29.5 ins.
No. of lands 34
Width of grooves 1/4 in.
De-th of grooves .050 in.
Width of lands 1/8 in.
Muzzle velocity (shell) 2,700 f/s
Max. range (horizontal) 17,000 yds.
Max. range (vertical) 32,800 ft. (fuze)
Rate of fire 10-12 rds.
Traverse 360°
Elevation 75°
Depression 10°
Length of recoil 19.3 ins.
Ammunition H.E. shrapnel; H.E. phosphorus
Wt. of projectile 45.75 lbs.

Japanese: p. 114.5 (August 1, 1945)