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Ch. III
 
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Japanese Tanks and Tank Tactics
Military Intelligence Service, Special Series No. 26, November 15, 1944
[DISCLAIMER: The following text is taken from a WWII U.S. War Department Special Series publication. As with all wartime intelligence information, data may be incomplete or inaccurate. No attempt has been made to update or correct the text. Any views or opinions expressed do not necessarily represent those of the website.]

Chapter III: Equipment

The Model 93 (1933) is an early example of the development of the light-tank series. The box-type hull is divided into three compartments. The center compartment is the fighting compartment, the superstructure of which overhangs the tracks. The right-hand side of the front of this compartment is extended forward to form a sponson for the ball-mounted machine gun. In the forward compartment the driver sits on the left, the gunner on the right.

Suspension is by six small rubber-tired bogie wheels mounted on three semielliptical springs on each side. There are three return rollers on each side, and drive is of the front-sprocket type. The track is center guide.

The turret mounts one machine gun to the front, and some pictures show a similar weapon mounted in the rear. Traverse of these weapons is 360 degrees. The turret is small, high, and rounded, with sloping sides.

 
MODEL 93 (1933) LIGHT TANK
Approximate specifications
1. Weight  7.8 tons.
2. Length14 feet 8 inches.
3. Width5 feet 11 inches.
4. Height6 feet.
5. Clearance15 inches.
6. Crew3 men.
7. ArmorUp to 22-mm (0.87 inch) (reported).
8. Armament1 MG light (hull) 1 MG light (turret).
9. SteeringClutch brake.
10. Ground contact10 feet.
11. Engine6-cylinder 85-horsepower Mitsubishi.
12. CoolingAir.
13. Width of track7 1/2 inches.
14. Pitch of track3 1/2 inches.
15. Diam. of sprocket1 foot 6 inches.
16. Diam. of rear idler1 foot 3 inches.
17. Height of sprocket center1 foot 8 inches.
Approximate maximum performance
1. Speed28 miles per hour.
2. Obstacles: 
       Trench5 feet 8 inches wide.
       Step1 foot 6 inches high.
       Ford2 feet 8 inches deep.
 

[ TBD ]
Figure 24.—Model 93 (1933) light tank.
 

 
MODEL 93 (1933) IMPROVED LIGHT TANK
Approximate specifications
1. Weight  7.8 tons.
2. Length14 feet 8 inches.
3. Width5 feet 11 inches.
4. Height6 feet.
5. Clearance15 inches.
6. Crew3 men.
7. ArmorUp to 22-mm (0.87 inch) (reported).
8. Armament1 37-mm tank gun, 1 turret MG.
9. Engine6-cylinder, 85-horsepower air-cooled Mitsubishi.
10. Ground contact9 feet 6 inches.
11. Width of track7 1/2 inches.
12. Track pitch3 1/2 inches.
13. Diam. bogie wheel15 inches.
14. SteeringClutch brake.
15. FuelGasoline.
Approximate maximum performance
1. Speed25 miles per hour.
2. Range of action120 miles.
3. Obstacles: 
       Trench5 feet 8 inches wide.
       Step1 foot 6 inches high.
       Ford2 feet 10 inches deep.
 

[ TBD ]
Figure 25.—Model 93 (1933) light tank (improved).
 

Model 94 (1934)

The Model 94 (1934) two-man light tank shows some pronounced variations from earlier designs. The hull is constructed of armor plate which reaches entirely around the vehicle and protects the interior from enemy fire. Both the turret and the suspension are mounted on the hull. Mudguards, suspension spring covers, the final drive covers, return rollers, and idler wheels are attached to the side plates of the hull.

Armor thickness has not been accurately ascertained. There are vision slits to the right and left of the driving compartment; in front of the lever-operated flap door of the driving compartment there is another vision aperture fitted with bullet-proof glass. There also is a sighting and firing aperture for a small-arms weapon. In front of the hull is an access plate which can be lifted for servicing the differential and the engine. The back plate also has an entrance hatch door and a special fitting for stowage. Apertures in the floor plate for lubrication of the engine and transmission are watertight. On the left of the top plate there are air-cooling and exhaust openings which, of necessity, must be exposed.

Suspension of the vehicle is somewhat unusual. Pairs of bogie rollers are carried at the ends of levers pivoted on the ends of bell cranks which, in turn, are pivoted in the hull structure. The vertical arms of the bell cranks are connected by rods to horizontal springs. The disc road wheels are of two-piece, built-up construction, with rubber tires; the return rollers also are fitted with rubber tires.

The gun turret, which has a tapered cross-section, is mounted on a ball and race for quick and easy rotation and forms a cover for the firing compartment. There is no rotation gear, however. The mantlet for the machine gun is ball-mounted and in two parts, and there is a turret traverse lock. In addition to the entrance hatch there are two vision apertures, a gun-sighting aperture, and an aerial mast opening. The interior of the turret, as well as the inner surfaces of plates surrounding the driving and fighting compartments of the hull, are lined with asbestos to protect the crew from engine and sun heat. One light machine gun is installed on a ball mounting.

The engine is a 4-cylinder, in-line, air-cooled model. It is old fashioned in design, having among other outmoded features a splash-type lubrication system. It is believed that it can develop about 50 horsepower at 1,700 revolutions per minute. Maximum speed of the tank is estimated at about 16.5 miles per hour.

Model 95 (1935)

The Japanese light tank most frequently encountered in the combat theaters to date is the Model 95 (1935). There is reason to believe that this vehicle was in production from 1935 to 1942, and evidence indicates that the design of Japanese light tanks was frozen to permit production of large numbers of this model.

While designed primarily to operate in soft, spongy ground, the chassis and power plant of this tank are adequate for satisfactory performance in all types of terrain where tanks normally can operate. High horsepower-weight ratio, high ground clearance, and the cleat construction of the track are factors that would insure good cross-country mobility. Fording is facilitated by the installation of leather gaskets on hatch covers which are below the level of the air-intake louvres.

Workmanship and design of the vehicle on the whole are good. The lavish use of aluminum and light alloys, as well as the equally prodigal employment of self-aligning ball-bearings, are striking features. The hull shows unmistakable evidence of complete redesigning. It is constructed over an angle-iron frame, with backing plates at the corners. The armor is 1/2 inch thick, except on the sloping portion from the front to the turret where it is only 1/4 inch. The armor is not well distributed, however, especially in the front where there are several reentrant angles. The hull is lined with a layer of woven asbestos padding which, although not considered effective protection against heat radiation, would provide some fire-proof protection for the crew.

The suspension makes use of an improved bell-crank design, with resistance provided by armored suspension springs mounted horizontally over the bogies. The horizontal springs give better track tension than would be afforded by volute springs, although crew and equipment are more subject to jarring, and the fire platform is not very stable. There are four bogie wheels mounted in pairs on each side, and two return rollers on each side. Suspension is designed to insure constant contact of the bogie wheels with the ground, irrespective of the nature of the terrain. Track pressure for a gross weight of 9 tons is 9.9 pounds per square inch.

[ TBD ]
Figure 26.—Model 95 (1935) light tank, right side.

[ TBD ]
Figure 27.—Model 95 (1935) light tank, left side. Note stowage.

[ TBD ]
Figure 28.—Model 95 (1935) light tank, right front view.

[ TBD ]
Figure 29.—Model 95 (1935) light tank, left front view.

[ TBD ]
Figure 30.—Model 95 (1935) light tank, front view.

[ TBD ]
Figure 31.—Model 95 (1935) light tank, rear view.

[ TBD ]
Figure 32.—Model 95 (1935) light tank, top view.
 

Idler Is Vulnerable

The vehicle has a front drive sprocket, 21 inches in diameter, and a rear idler of the same size. The rear idler is held by a single bracket, and its design permits quick and easy tightening of the track tension merely by employment of an 8-inch crescent wrench. This idler and its mounting are without covering and therefore very vulnerable. Indeed, there is a verified report that an Australian infantryman crippled a Model 95 tank by a hit on the idler mounting with a .303 caliber rifle bullet.

A rounded turret with a square front is mounted on a medium high superstructure. The sides of the superstructure protrude over the top of the tracks, which are 10 inches wide with a pitch of 4 inches. The turret is manually operated by a lever on the left side. The turret gunner's space is very cramped, and no seat is provided. When the turret is in a position from 1 to 5 o'clock, visibility to the right is very poor. When the turret is in a 1 to 3 o'clock position it overhangs the hull and easily can be wedged and jammed. A gap of from 3/16 to 1/2 inch between the turret and the hull, depending upon the position of the former, presents a point of great vulnerability, for when the gunner traverses the turret this slit is open to attack all around.

The driverís hatch is 13 inches square and has a small door 6 inches square. Both horizontal and vertical vision slits are in the door. There is a peep hole, 2 inches in diameter, on each side of the bow gun. Along the top portion of the turret are six equally spaced vertical and horizontal slits which offer limited visibility despite their number. The absence of glass visor blocks makes these slits very vulnerable to machine-gun and even rifle fire. The driver's slit is vulnerable to splash from ordinary .30 caliber rifle ammunition. Two air vents in the engine compartment are open to attack by Molotov cocktails, and only two quart-size hand fire extinguishers are available to the crew to cope with fires started in this fashion.

The vehicle is powered by a 6-cylinder, in-line Diesel engine which develops 110 horsepower at 1,400 revolutions per minute and 200 to 250 horsepower at 2,000. The engine has ample power and good acceleration but its starting is sluggish. It is air-cooled with turbo impellers. Fuel injection system and oil pumps, as well as starter and generator, are of Bosch manufacture. The fuel capacity is 23 gallons, with six gallons in reserve.

 
MODEL 95 (1935) LIGHT TANK
Specifications from actual examination
1. Weight  10 tons (loaded).
2. Length14 feet 4 inches.
3. Width6 feet 9 inches.
4. Height7 feet.
5. Clearance15 1/2 inches.
6. Crew3 men.
7. Armor6 to 12-mm (0.24 to 0.47 inch).
8. Armament37-mm type 94 tank gun, 1 7.7-mm rear
turret MG, 1 7.7-mm hull MG.
9. Ammunition 
       37-mm130 rounds.
       MG2,970 rounds.
10. Engine110 horsepower at 1,400 RPM (240 theoretically
    indicated HP at 2,000 RPM—based on reported
    engine specifications).
11. Transmission4 speeds forward, 1 reverse.
12. SteeringClutch brake.
13. Ground contact7 feet 8 inches.
14. Width of track9 7/8 inches.
15. Track pitch3 3/4 inches.
16. Diam. sprocket21 inches.
17. Diam. bogie wheel22 1/4 inches.
18. Diam. rear idler21 inches.
19. Height to center of sprocket32 inches.
Approximate maximum performance
1. Speed28 miles per hour.
2. Range of action100 miles.
3. Gradient40°.
 30° for long climb.
4. Obstacles: 
       Trench6 feet wide.
       Step2 feet 8 inches high.
       Ford3 feet 3 inches deep.
 

 
THE LIGHT TANK "KENI" MAY BE A FOURTH VARIATION OF THE MODEL 95:
Approximate specifications
1. Weight  7.7 tons.
2. Length13 feet 6 inches.
3. Width7 feet.
4. Height5 feet 11 inches.
5. Ground clearance14 inches.
6. Crew3 men.
7. Armament1 47-mm gun and 1 MG.
8. Armor6- to 16-mm (0.24 to 0.63 inch).
9. Engine140 horsepower.
Approximate maximum performance
1. Speed31 miles per hour.
2. Gradient34°.
3. Obstacles: 
       Trench6 feet 7 inches wide.
       Ford2 feet 3 inches deep.
 

[ TBD ]
Figure 33.—Model 95 (1935) light tank showing suspension. Note pistol ports.

[ TBD ]
Figure 34.—Model 95 (1935) light tank. Track-adjusting nut and assembly.

[ TBD ]
Figure 35.—Model 95 (1935) light tank, steering assembly.

[ TBD ]
Figure 36.—Model 95 (1935) light tank turret. Photograph shows how a knife blade will jam turret when forced into crevice between turret and tank body.

[ TBD ]
Figure 37.—A small brick or any hard object will jam the turret of the Model 95 (1935) light tank when turret is turned to overhang hull of tank.

[ TBD ]
Figure 38.—Model 95 (1935) light tank. Six-cylinder, in-line, air-cooled Diesel engine.

[ TBD ]
Figure 39.—Rear view of Model 95 (1935) light tank, showing fuel oil filler cap, motor oil storage tank and filler cap, and two rear idler brackets.

[ TBD ]
Figure 40.—Interior of turret of Model 95 (1935) light tank.

[ TBD ]
Figure 41.—Interior of driving compartment of Model 95 (1935) light tank.
 

The tank is quite maneuverable, despite the use of disc-clutch steering. When a clutch lever is pulled to a half-way position, the clutch is disengaged; when pulled all the way back, the outside drum brake is set to permit sharper turning.

A 37-mm tank gun is installed in the turret, which also mounts a .30 caliber light machine gun in the right rear. There is another .30 caliber machine gun forward in the hull. The turret guns have a 12-degree elevation, a 16-degree depression, and a traverse (total) of 45 degrees. Ammunition for the 37-mm gun is carried in clips and racks in the fighting compartment; ammunition for the machine guns is carried in magazines under the forward machine gun and in the fighting compartment.

Armor Too Light

Mention has been made of a number of vulnerable points in the design and construction of the Model 95. Its light armor, especially on the underside of the sponsons, is perhaps its outstanding weakness. In actual combat, 75-mm HE shells blew the turrets completely off several of these tanks. In another instance, a 75-mm AP shell fired at a range of from 100 to 500 yards entered the right front of a Model 95 and came out the rear, leaving a hole one foot in diameter all the way through. The external exhaust manifold, the suspension mechanism, and the idler are vulnerable to machine-gun fire, while the bogie wheels can be destroyed by hand grenades. While definitely an improvement upon earlier models, the Model 95 is considerably below the standard of the light tanks as used in United Nations armies.

Amphibious Light Tank

A new type amphibious light tank recently found on Kwajalein Atoll shows the most modern trends yet seen in Japanese armored vehicles. The hull, which is not divided into compartments, is larger and roomier than that of the Model 95, and bulkheads have been eliminated. Armor protection is slightly increased with the front and turret having 1/2 inch; the sides, rear and bottom, 3/8 inch; and the top of both turret and hull, 1/4 inch. The tracks have been widened to 12 inches, and the idler has been superseded by a trailing idler. The hull is welded throughout and all reentrant angles have been eliminated. Machine-gun fire of .30 caliber is effective only at the slits, but .50 caliber fire will penetrate the sides of the hull.

Suspension closely resembles that of the Model 94 and Model 97 tankettes except that the compression springs are mounted inside the vehicle. There are four bogies in pairs on each side mounted on a traverse even lever. The rear trailing idler serves as an additional bogie. The engine is a 6-cylinder, air-cooled Diesel with no important new features distinguishing it from that used in the Model 95. Japanese ratings state that the land speed is 23 miles per hour maximum and the speed in water 6 miles per hour. Fuel capacity is 55 gallons.

The round turret is a new design characterized by considerably increased diameter in comparison with earlier models. A Model 1 (1941) 37-mm tank gun, which is a modification of the Model 94 antitank gun, is mounted coaxially with a 7.7-mm machine gun. These guns have a 360-degree traverse, a 5 1/2-degree elevation, and a 11 1/2-degree depression. The 37-mm gun has a higher muzzle velocity than the guns of the same caliber mounted in earlier model tanks. Tests have indicated that it is 2,212 feet per second for AP shell that would pierce 1.8 inches of armor at normal impact.

The flotation equipment for using the tank in water is interesting. Pontons are attached to both bow and stern of the vehicle. These pontons conform to the shape of the hull and are attached by a series of pincer clamps controlled by a handwheel inside the tank. The bow ponton, which is in six sections, has a volume of 220 cubic feet; the stern ponton in five sections, 105 cubic feet. The rudders are situated in the stern pontons and are operated from within the hull; the propellers are fitted to the rear of the tank. To prevent entrance of water, all openings up to and including the turret ring are rubber sealed.

 
AMPHIBIOUS LIGHT TANK
Specifications
1. Weight:   
       Tank (only)13 tons (estimated).
       Pontons (only)3 tons (estimated).
2. Length:
       Tank (only)15 feet 8 inches.
       With pontons24 feet 7 inches.
3. Width9 feet 2 inches
4. Height7 feet 6 inches.
5. Ground clearance14 inches.
6. Crew5 men.
7. Armor: 
       Turret: 
              Sides13.2-mm (0.52 inch).
              Top6-mm (0.24 inch).
       Hull: 
              Front12-mm (0.47 inch).
              Sides9-mm (0.35 inch).
              Rear8-mm (0.32 inch).
              Top6-mm (0.24 inch).
              Bottom8.5-mm (0.334 inch).
8. Armament1—37-mm Model 1 (1941) in turret,
    1—7.7-mm MG coaxially mounted,
    1—7.7-mm MG in hull forward.
9. Engine6-cylinder air-cooled Diesel (reported to
    be identical with that in the Model 95
    light tank).
10. Fuel capacity66 gallons (2 tanks).
11. Suspension2 bogies on each side of vehicle. Bogies
    consist of 2 wheels mounted on a
    transverse even lever. Rear trailing
    idler serves as an additional bogie.
12. Track 
       Length, overall32 feet 1 inch.
       Ground contact11 feet 1 inch.
       Width1 foot.
       Angle of approach56 1/4°.
13. Vision apertures and pistol ports: 
       Hull1—4 x 1 inch slit for driver.
    1—4 x 1/8 inch slit for hull gunner.
    4 pistol ports, one on each quarter of the hull.
       Turret2—3.75 inch diameter vision ports, one
    on each side of 37-mm gun.
2—4 x 1/8 inch slits, one on each side of turret.
3 pistol ports, one at each side and one
    at the rear.
       Safety glassShatter-proof blocks are clamped over
    all vision slits to prevent "bullet splash"
    or entrance of water. Vision ports are
    protected by 3-inch safety glass windows.
 

[ TBD ]
Figure 42.—Right front view of amphibious tank without pontons.

[ TBD ]
Figure 43.—Rear view of amphibious tank without pontons.

[ TBD ]
Figure 44.—Rear view of amphibious tank knocked out by Marine artillery at Saipan.

[ TBD ]
Figure 45.—Rear view of amphibious tank.

[ TBD ]
Figure 46.—Amphibious tank with bow ponton attached.

[ TBD ]
Figure 47.—Disengagement of bow ponton of amphibious tank.

[ TBD ]
Figure 48.—Amphibious tank showing rear ponton attached.

[ TBD ]
Figure 49.—Section of rear ponton of amphibious tank. Note tiller.
 

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