Tag: Japanese

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Japanese

105 mm Field Gun Type 14

Japanese 105 mm Field Gun Type 14

The Japanese 105 mm gun, Type 14, is a medium field weapon mounted on a two-wheeled carriage and drawn by a prime mover. The tube, of built-up construction, is retracted above the trails when in traveling position to provide proper balance. A breechblock of the interrupted screw type is used.

The weapon has split trails which may be adjusted to equalize cant. The wheels are equipped with rubber or steel tires.

The recoil system is the variable, hydropneumatic floating piston type. The fluid passage to the other side of the two air cylinders is suitably interrupted when the elevation is increased.

The traversing mechanism consists of a worm and arc gear. The elevating mechanism is of the arc gear type. A spring equilibrator is attached to the gun, since the trunnion is retracted in relation to the tube. The sighting equipment consists of a panoramic sight and a drum type range scale.

SPECIFICATIONS

Caliber         105 mm (4.13 ins.)
Weight (traveling position)
Weight (firing position)
Length (traveling position)
Length (firing position)
Height (traveling position)
Height (firing position)
Width (overall)
Width of trail spread
Length of bore
No. of grooves
Width of grooves
Depth of grooves
Width of lands
Muzzle velocity 2,040 f/s
Max. range (horizontal) 16,500 yds.
Max. range (vertical)
Rate of fire 6-8 r.p.m.
Traverse 30°
Elevation 43°
Depression 5°
Length of recoil
Ammunition H.E. (long pointed), H.E., Shrapnel, Chemical, A.P.
Wt. of projectile (H.E.) 33 lbs.

German: p. 114.3 (August 1, 1945)

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Japanese

81 mm Mortar Model 3

Japanese 81 mm Mortar Model 3

The Japanese 81 mm Mortar, Model 3, is a forerunner of the Model 97 (1937). It was manufactured at the Yokosuka Navy Arsenal in 1943.

The tube is a smooth-bore type and has two collars machined on the forward part for securing the bipod clamp. The bipod, constructed of light weight tubing, is very unstable. There is no cross leveling device, and rough cross leveling adjustments could be made by breaking the bipod support and moving the leg on the low side inward.

The base plate is relatively heavy, and is believed to be identical with that now used with the 90 mm Mortar, Model 94. It is interchangeable with the base plate for the Model 97.

Both traversing and elevating mechanisms employ the square type threads rather than the usual and more efficient buttress type as used on Model 97. No sight was recovered with the mortar.

SPECIFICATIONS

Weight of tube        47 lbs.
Weight of bipod 25 lbs.
Weight of base plate 95 lbs.

Japanese: p. 122.1

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Japanese

Anti-Vehicular Yardstick Mine

Japanese WWII Anti-Vehicular Yardstick Mine

This Japanese land mine, of Naval origin, is usually found buried in landing strips. Almost any vehicle will activate the mine, but its use as an anti-personnel device is limited since a pressure of approximately 336 pounds is necessary to set it off.

The mine consists of an oval shaped tube of sheet metal with a cap on both ends; an explosive charge comprising eight blocks of picric acid, each cast in a paper container and coated with paraffin; and four percussion type fuzes.

The picric acid blocks which are flattened on one side do not fill the mine completely. The space between the flat side of the blocks and the wall of the case accommodates the protruding heads of the fuzes which are inserted between blocks.

The percussion type fuze consists of a cylindrical body which houses the striker release plunger, a booster housing, and a striker housing. The two latter parts are identical in external appearance and screw into the sides of the main body diametrically opposite each other.

The striker release plunger, a split pin with an enlarged flat head, is positioned in the fuze body by a copper shear wire. A second hole 90 degrees from the shear wire hole accommodates a safety wire. The lower end of the plunger is split by a slot, the width of which is increased on the inner end.

The mine is held in an unarmed position by the safety wire which is inserted through a hole in one of the end caps, and extends the entire length of the mine. A spring clip on the cap holds the wire in place. When the mine is to be put into operation, the safety wire is removed and a burying plug is screwed into the hole in the cap to make the assembly waterproof. A thick tarry substance is applied to-the seams around the end caps probably for the same purpose.

SPECIFICATIONS

Length (overall)        36 ins.
Diameter (oval) 3.35 x 1.8 ins.
Total weight 10.58 lbs.
Weight of mine 4.63 lbs.
Weight of filling 5.95 lbs.
Weight of each explosive block 3/4 lb.
Filling Picric acid
Weight of complete fuze .29 lb.
Color Brown outside; black lacquer inside

Japanese: p. 308.1 (March 1, 1945)

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Japanese

Armored Tracked Personnel Carrier

Armored-tracked Personnel Carrier: Type 1 Ho-Ki

This vehicle serves as an artillery prime mover and as a personnel carrier for 24 men. It appears to be of recent manufacture, and its first known appearance in combat was during the Leyte campaign in the Philippines.

It is a full-tracked vehicle armored with 1/4-inch plate throughout. The engine which is located at the right front of the body is a 6-cylinder, in-line, valve-in-head, air-cooled diesel of a type similar to those used in the Model 2595 light tank and the combination prime mover and wrecker. Two fuel tanks provide an estimated total capacity of 50 to 60 gallons.

The tracks and suspension are of the conventional Japanese design, using dual bogie wheels and a steel center guide track. The four bogie wheels, apparently identical with those on the Model 2595 light tank, are mounted on bell cranks and are sprung by horizontal coil springs which are inclosed within the body armor with only the bogie arms exposed. There are two return rollers. The track is driven from the rear. A clutch and brake steering system is used. The transmission provides four speeds forward and one reverse. A high and low transfer case is also provided.

A mount for a 7.7 mm machine gun is located on the left front of the driver’s compartment. The vehicle does not mount a winch, but is provided with a spring mounted towing pintle for use as a prime mover. It has a capacity of from 2 to 3 tons if used as a cargo carrier. Maximum speed is reported as approximately 35 miles per hour, with exceptionally good cross-country performance due to the amount of track area in contact with the ground in relation to the weight of the vehicle.

SPECIFICATIONS

Weight
Length (overall)       15 ft., 9 ins.
Width (overall) 6 ft., 8 ins.
Height
Ground clearance
Tread centers
Ground contact 9 ft., 10 ins.
Width of track 10 ins.
Pitch of track 3-13/16 ins.
Track links 125
Fording depth
Theoretical radius of action
     Roads
     Cross-country
Speed (maximum) 35 m.p.h.
Armor (reported) 1/4 in.
Armament 7.7 mm machine gun
Ammunition (Rds.)
Engine 6-cylinder, in-line, valve-in-head, diesel.
Transmission 4 speeds forward, 1 reverse; high and low range.
Steering Clutch and brake system
Seating capacity 24

Japanese: p. 18.3 (May 1, 1945)

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Japanese

57 mm Tank Gun Model 97

57 mm Japanese Tank Gun Model 97

This gun, manufactured at Osaka Arsenal in 1939, is mounted on the Japanese Medium Tank Type 97. The tube, of monobloc construction, is fastened to the breech ring by twelve interrupted threads and secured by a lock on the right side of the tube. The breech ring is box-shaped. The breechblock of the vertical sliding type rides in two dovetailed slots in each side of the breech ring, and may be operated manually or semi-automatically.

The firing pin is automatically cocked when the breech is opened. The trigger, on the left side of the gunner’s shield, is protected by a trigger guard with a pistol grip. The recoil mechanism is a hydro-spring type.

The gun is mounted in the turret of the tank, and has a 360° traverse. It may also be freely elevated or traversed independently of the turret by means of two sets of trunnions. The inner vertical trunnions are set in a heavy steel bracket fitted to the cradle and permit a 5° left and right traverse. The bracket has a sighting window which may be closed for the gunner’s protection. The outer horizontal trunnions fit into another steel bracket and give approximately 11° elevation and 9° depression.

Although no sighting equipment was recovered with the gun, the appearance and location of the head rest, shoulder rest, and sight bracket indicate that a straight tube telescope is used.

SPECIFICATIONS

Caliber         57 mm
Weight of tube and breech ring 138 lbs.
Weight (firing position) 293.5 lbs.
Length of tube and breech ring 41 5/8 ins.
Length (firing position)
Height (traveling position)
Height (firing position)
Width (overall)
Width of trail spread
Length of tube and breech ring 41 5/8 ins.
Rifling R.H., uniform twist; approx. 1 turn in 28 1/2 cals.
Length of rifling 32.5 ins.
No. of grooves 20
Width of grooves .25 in.
Depth of grooves .039 in.
Width of lands
Muzzle velocity (shell)
Max. range (horizontal)
Max. range (vertical)
Rate of fire 20 r.p.m.
Traverse 360° with turret and 5° right and left independent of turret
Elevation 11°
Depression 9°
Length of recoil 11 ins.
Ammunition H.E. and A.P.H.E.
Wt. of projectile

Japanese: p. 106.2 (August 1, 1945)

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Japanese

6.5 mm Heavy Machine Gun Model 3 (1914)

6.5 mm Heavy Machine Gun Model 3 (1914)

The Japanese 6.5 mm Model 3 Heavy Machine Gun, a gas-operated, air-cooled, full-automatic weapon with a comparatively low cyclic rate, although obsolescent, is being recovered in small quantities from battle areas. It is similar to the 7.7 mm Model 92, but is chambered for the 6.5 mm cartridge.

The gas piston and bolt assemblies, and the barrel and barrel sleeve may be interchanged in the two weapons. However, it is impossible to convert the Model 3 for use with the 7.7 mm ammunition as the strip feed port in the Model 3 is one-eighth of an inch narrower than that in the Model 92.

Various machining cuts found in the internal parts of the Model 3 were eliminated in the later model, to provide for ease of production. The oil reservoir is of slightly different shape and probably has a lower capacity than that of the Model 92. The trunnions are of two diameters. The part of the trunnion which contacts the trunnion bearing in the mount is of smaller diameter than that portion which extends beyond the mount. The head thus formed tends to reduce transverse motion.

The weapon has conventional spade grips provided with two finger triggers fixed integrally with the trigger lever so that either or both will fire the gun. There is no safety device.

Two rear sights are provided: one, a folding ring type anti-aircraft sight, is attached permanently to the rear top of the receiver; the other, a tangent curve, radius arm type, is offset to the right. The latter sight is graduated from 300 meters to 2,200 meters (328 yards to 2,406 yards). It is believed that a cartwheel typefront sight is used, as an adaptor for such a sight is riveted to the front of the cooling jacket.

SPECIFICATIONS

Weight (w/ tripod)         122 lbs.
     (w/o tripod) 61.7 lbs.
Length 47.2 ins.
Sight radius 23.6 ins.
Principle of operation Gas
Feeding device Metal strips
Capacity of feeding device 30 rounds
Cooling system Air
Ammunition types Mod. 38, 6.5 mm ball ammunition
Rate of fire Cyclic — 450-500 r.p.m.
  Practical — 200 r.p.m.
Type of sight Two rear sights: folding ring, antiaircraft type; tangent curve, radius arm type, grad. 328-2,406 yds.
Weight of barrel
Length of barrel 29.2 ins.
Length of rifling 26.4 ins.
Rifling
     Twist Uniform, R.H., one turn in 7.88 ins.
     Form Metford segmental
     No. of grooves 4
Depth of grooves
Width of grooves
Chamber pressure 58,800 lbs. per sq. in.
Muzzle velocity 2,434 ft. per sec.
Muzzle energy
Maximum range 4,376 yds.
Effective range 1,500 yds.
Type of mount Tripod
Elevation -15° to +90°
Traverse 33.5°

Japanese: p. 210.1

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Japanese

7.7 mm Lewis Machine Gun Model 92 (1932)

7.7 mm Lewis Machine Gun Model 92 (1932)

The Lewis type machine gun is used widely by the Japanese. Markings on a number of these guns found in the New Georgia area indicate that the weapon as used by the Japanese is of naval origin. It is also believed that the gun is used extensively for ship or air base protection as the tripod mount is adaptable for antiaircraft fire.

The Model 92 is of standard Lewis gas-operated, air-cooled, drum-fed design, equipped with a blade front sight and a rear peep-sight calibrated in hundreds of meters from 0 to 17. No allowance is made for windage or drift. Although no antiaircraft sight was discovered with the gun, a mount for such a sight is attached to the weapon.

The gun is mounted on a tripod having tubular steel legs which may be locked at various angles from the vertical. The tripod legs are attached to flat square plates which have holes in the center to accommodate bolts which are used to secure the tripod to the deck of a ship.

The head of the tripod has a 360° traverse. Without removing the gun from the mount, the main portion of the tripod head can be moved from a horizontal to a vertical position, and the gun attached to the top of the head for antiaircraft use. In this position, the limits of elevation are approximately -80° to +85°. Azimuth is calibrated in 2 mil intervals from 0 to 6,400 mils.

7.7 mm rimmed Navy ammunition fed from a 47-round drum is used. Ammunition chests recovered were found to hold 21 loaded drums.

SPECIFICATIONS

Weight gun and tripod       122 lbs.
Length 39 ins.
Principle of operation Lewis gas-operated system
Feeding device Drum magazine
Capacity of feeding device 47 rounds
Cooling system Air
Ammunition types 7.7 mm full-rimmed ammunition
Rate of fire Cyclic-600 r.p.m.
Type of sight Blade front sight: rear peepsight calibrated from 0 to 1700 meters
Weight of gun 49 lbs.
Length of barrel 24 ins.
Length of rifling
Rifling
     Twist Uniform, R.H.
     Form Concentric
     No. of grooves 4
     Depth of grooves
     Width of grooves
Chamber pressure
Muzzle velocity 2411 ft. per sec.
Muzzle energy
Maximum range 4000 yds.
Effective range 500 yds.
Type of mount Tripod
Elevation
Ground mount -15° – +60°
Antiaircraft mount -80° – +85°
Traverse 360°

Japanese: p. 214.1 (June 1, 1945)

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Japanese

“Kato” General Purpose Tractor

Kato General Purpose TractorThis is a commercial type wheeled tractor used for general purpose work. The front wheels are 29 x 5 inches and the rear dual wheels are 40 x 10 inches, all fitted with solid rubber tires. The drive is from the rear wheels only, and steering is effected by a worm gear system operating the front wheels. Normal automotive controls are provided, save for a hand throttle. The transmission provides three speeds forward and two in reverse.

The K3 type engine is identical to that used in the “Kato” 70 tractor–a 4-cylinder, valve-in-head, gasoline type. There are two cylinder blocks of two cylinders each instead of a solid cylinder block. The generator, high-tension magneto, and water pump are all linked together with universal joints and driven from a single shaft extending from the timing gear on the right of the engine.

The tractor is fitted with front and rear towing pintles cast solid with the frame.

SPECIFICATIONS

Weight          
Winch capacity
Length
Wheel base 90 ins.
Overall width of tractor (rear) 74 ins.
Overall height of tractor 5 ft.
Capacity of fuel tank 30 gals.
Tread centers (front) 63 ins.
Ground clearance 8 ins.
Fuel capacity (approx.) 30 gals.
Engine 60 h.p. at 1,200 r.p.m.
Bore 121 mm
Stroke 152 mm

Japanese: p. 18.6 (August 1, 1945)

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Japanese

8 mm Paratrooper’s Submachine Gun, Type 100 (1940)

japanese-paratrooper-8mm-submachine-gun

This Japanese paratrooper’s submachine gun is a light, blowback operated, automatic weapon which fires the regular issue bottle-necked 8 mm pistol cartridge.

The gun, which is provided with a bayonet, also has a folding stock; that is, the stock is cut through just behind the receiver and hinged so that by releasing two locking hooks on the left side, the stock swings to the right and forward 180 degrees at the hinge and parallel with the barrel. The barrel and barrel jacket are held in place by a single screwpin threaded at the base and with a folding wingnut head, enabling changes without tools. The receiver assembly is machined in two units, with the units shrunk fit in final assembly.

Two features of the firing mechanism which are of unusual interest are the fixed firing pin which screws into the face of the bolt, and the feeding and chambering bar which insures that the cartridge is very nearly chambered before the firing pin can touch the primer.

In the illustrations above, the top picture shows the weapon as fired, and the photograph at lower left shows the method of folding. A bipod is frequently used with this gun as illustrated in the photograph at lower right.

SPECIFICATIONS

Caliber       8 mm
Weight (without bayonet, magazine, & sightleaf) 7 lbs., 11 ozs.
Length (stock extended, without bayonet) 34 ins.
Length (stock extended, with bayonet) 49 ins.
Length (stock folded, without bayonet) 22.25 ins.
Sight radius 20 ins.
Principle of operation Blowback, bolt action
Feeding device Curved box magazine; staggered feed type.
Capacity of feeding device 30 rounds
Cooling system Air
Ammunition types 8 mm bottle-necked pistol cartridges
Rate of fire 400-450 r.p.m.
Type of sight Leaf
Length of barrel 9 ins.
Length of rifling 8.125 ins.
Rifling
     Twist Uniform R.H., approx. 1 in 12
     No. of grooves 6
Muzzle velocity 1,080 f/s

Japanese: p. 204.1 (August 1, 1945)