The oldest model medium tank which has been employed by the Japanese in the current war is the 89A (1929). It is characterized by a box-shaped hull which has a short front plate with a door to the right. Above the short front plate is a vertical front plate, through the right side of which protrudes a light machine gun. A small cupola is hinged to the top of the turret.

The suspension has nine small bogie wheels on each side with the leading ones independently mounted. There are five return rollers on each side mounted along a girder, and the vehicle is rear-sprocket driven. A protective skirting almost entirely covers the suspension. Power is furnished by a gasoline engine. The main armament is a 57-mm low-velocity gun mounted, with a 360-degree traverse, in the turret. There also is a rear-turret light machine gun.

 
MODEL 89A (1929) MEDIUM TANK

Approximate specifications
1. Weight		13 tons.
2. Length		19 feet 3 inches.
3. Width		7 feet 1 inch.
4. Height		8 feet 6 inches.
5. Clearance		19 inches.
6. Crew		4 men.
7. Armor		6 to 17-mm (0.24 to 0.67 inch), also     reported as 17- to 25-mm (0.67 to     0.98 inch).
8. Armament		1 57-mm, 1 hull MG, 1 rear turret MG.
9. Ammunition		57-mm 100 rounds, SAA 2,745 rounds.
10. Engine		136 brake horsepower.
11. Ground contact		12 feet.
12. Width of track		12 inches.
13. Track pitch		6 inches.
14. Diam. rear sprocket		30 inches.
15. Diam. bogie wheel		9 inches.
16. Diam. front idler		36 inches.
17. Height to center of idler		33 inches.
18. Fuel		Gasoline.
Approximate maximum performance
1. Speed		15 miles per hour.
2. Range of action		100 miles.
3. Gradient		34°.
4. Obstacles:
Trench		8 feet 3 inches wide.
Step		2 feet 9 inches high.
Ford		3 feet 3 inches deep.

 

Model 89B (1929)

The Model 89B (also sometimes reported as Model 92 [1932]) medium tank differs from the Model 89A in that it has a longer front which combines with the driver’s front plate. Also, the turret has been completely redesigned to include a new type of cupola and a more satisfactory aperture for mounting the 57-mm gun. While armament and armor thickness have remained the same, the gasoline engine of the 89A has been replaced by a Diesel engine.

 
MODEL 89B (1929) MEDIUM TANK

Approximate specifications
1. Weight		13 tons.
2. Length		19 feet 3 inches.
3. Width		7 feet 1 inch.
4. Height		8 feet 6 inches.
5. Clearance		19 inches.
6. Crew		4 men.
7. Armor		6 to 17-mm (0.24 to 0.67 inch), also     reported as 17 to 25-mm (0.67 to     0.98 inch).
8. Armament		1 57-mm, 1 hull MG, 1 rear turret MG.
9. Ammunition		57-mm 100 rounds, SAA 2,745 rounds.
10. Engine		120 Brake horsepower.
11. Ground contact		12 feet.
12. Width of track		12 inches.
13. Track pitch		6 inches.
14. Diam. rear sprocket		30 inches.
15. Diam. bogie wheel		9 inches.
16. Height to center of idler		33 inches.
Approximate maximum performance
1. Speed		15 miles per hour.
2. Range of action		100 miles.
3. Gradient		34°.
4. Obstacles:
Trench		8 feet 3 inches wide.
Step		2 feet 9 inches high.
Ford		3 feet 3 inches deep.

 

Model 94 (1934)

The Model 94 (1934) medium tank has been used extensively by the Japanese in China, although it now is considered obsolete. There are a number of resemblances between this tank and Models 89A and 89B. The Model 94, however, has a long front plate with a door on the left, above which is mounted the hull machine gun.

Suspension is similar to that of the earlier models except that, while there are still nine bogie wheels on each side, the number of return rollers has been reduced from five to four. The girder upon which the return rollers were mounted in the 89A and 89B models has been removed and the skirting has been redesigned. The superstructure protrudes over the top of the bogie wheels which are almost completely hidden by the skirting. The tank often is equipped with a ditching tail which, by increasing its length, improves its performance in crossing trenches.

The armor is 0.67 inches thick on the front; the turret is 0.43 inches on the sides. It is reported without confirmation that armor thickness may have been increased to 0.98 inches. The turret is more rounded than in the earlier models and has sloping sides. The power of the engine has been increased to about 160 brake horsepower.

A 37-mm tank gun is mounted in the turret, and a machine gun on a ball mount is installed in the rear of the turret. There is another light machine gun in the left front of the hull.

 
MODEL 94 (1934) MEDIUM TANK

Specifications
1. Weight		15 tons.
2. Length (including ditching tail)		23 feet.
3. Width		7 feet 1 inch.
4. Height		8 feet 6 inches.
5. Clearance		19 inches.
6. Crew		4 men.
7. Armor		6 to 17-mm (0.24 to 0.67 inch).
8. Armament:
Main		1 57-mm gun.
MG		1 Hull MG. 1 rear turret MG.
9. Ammunition		57-mm 100 rounds, SAA 2,750 rounds.
10. Engine		160 brake horsepower air-cooled Diesel.
11. Ground contact		12 feet.
12. Width of track		12 inches.
13. Track pitch		6 inches.
14. Diam. rear sprocket		30 inches.
15. Diam. front idler		36 inches.
16. Diam. bogic wheel		9 inches.
17. Height to center of front idler		33 inches.
Approximate maximum performance
1. Speed		20 miles per hour.
2. Range of action		100 miles.
3. Gradient		34°.
4. Obstacles:
Trench		9 feet wide.
Step		2 feet 9 inches high.
Ford		3 feet 3 inches deep.

 

Model 97 (1937)

Another Japanese tank that has been encountered in several combat theaters, including Guadalcanal and Burma, is the Model 97 (1937). It probably was produced in the period 1937-1940, and its design represents the incorporation of experience gained in the Chinese operations. It is the first tank to be found equipped with smoke projectors. Another interesting feature is the installation of glass visor blocks over vision apertures, correcting a serious deficiency that existed in earlier models.

Armor is considerably thicker than in earlier medium tank models, with 1 inch in front and on the turret, and 0.86 inch on the sides. Backing plates are used to reinforce the hull joints and corners. The vehicle is quite vulnerable, however, not only because of the lightness of the armor in comparison with tanks of other armies but also because of the absence of welded construction. Both hull and turret plates are assembled almost entirely by bolts and rivets.

Suspension differs sharply from that of previous models. There are six bogie wheels on each side, with the four central ones on each side paired, while each end bogie wheel is independently bell-crank mounted to the hull. When viewed from the side, all the wheels seem independently mounted. There are three return rollers on each side, with the center one carrying only the inside half of the track. Drive is of the front-sprocket type.

The rounded turret is set centrally; the handrail sometimes seen around it is not always installed. The main armament is a 57-mm tank gun, which has a 20-degree traverse but no elevating mechanism. There is a 7.7-mm machine gun in the rear of the turret, and a similar weapon is installed in the front of the hull.

Power is provided by a Diesel, 12-cylinder, V-type engine. It is air-cooled and valve-in-head, developing 170 horsepower at maximum output. Cylinder heads and crankcase are made of cast aluminum. The fuel system is the high-pressure type, with Bosch injectors placed directly over the pistons.

Two types of steering are utilized. One is the clutch-brake type, similar to that on other Japanese tanks, which is used for skid turns. External dry brake bands increase the sharpness of the turn after the clutch is disengaged. A form of epicyclic steering is used for normal turning movements. Clutches which are of the multiple-disc type have cast aluminum housings. Transmission is of the conventional sliding-gear type, with five forward speeds and one reverse.

 
MODEL 97 (1937) MEDIUM TANK

Specifications by examination
1. Weight		15 tons.
2. Length		18 feet.
3. Width		7 feet 8 inches.
4. Height		7 feet 8 inches.
5. Clearance		16 inches.
6. Crew		4 men.
7. Armor		8 to 25-mm (0.32 to 0.98 inch).
8. Armament:
Main		1 57-mm Model 97 gun.
Hull		1 7.7-mm Model 97 MG.
Rear Turret		1 7.7-mm Model 97 MG.
9. Ammunition		57-mm 80 rounds HE—40 rounds APHE,     MG 2,350 rounds ball, 1,350 AP.
10. Engine		12 cylinder Diesel.
11. Horsepower		150 (365 theoretically indicated HP at     2,000 RPM—based on reported engine     specifications.
12. Transmission		4 speeds forward, 1 reverse—high low range.
13. Steering		Clutch brake.
14. Ground contact		12 feet 8 inches.
15. Width of track		13 inches.
16. Track pitch		5 inches.
17. Diam. front sprocket		23 inches.
18. Diam. rear idler		23 inches.
19. Diam. bogie wheel		21 inches.
20. Height to center of sprocket		32 1/2 inches.
21. Fuel consumption		4 gallons per hour.
Approximate maximum performance
1. Speed		25 miles per hour.
2. Radius of action		100 miles.
3. Gradient		34°.
4. Obstacles:
Trench		8 feet 3 inches.
Step		2 feet 6 inches high.
Ford		3 feet 3 inches deep.

 

Model 97 Modified

A medium tank very similar to the Model 97 was used by the Japanese in the operations on Corregidor. With the exception of the turret and main armament it is the same as the Model 97. The turret is modified to accommodate a high-muzzle-velocity gun believed to be of 47-mm caliber. It also has a rear turret machine gun. The long over-hanging rear portion of the turret probably has been designed to permit simultaneous firing of the tank and machine guns.

Variations of Model 97 captured on Saipan had a much longer turret to accommodate a long-barreled Model 1 (1941) 47-mm gun. Another captured near Imphal likewise was armed with a 47-mm gun but did not differ materially from the specifications listed in other respects.