The Type 97 Chi-Ha (九七式中戦車 チハ Kyūnana-shiki chū-sensha Chi-ha?) was a medium tank used by the Imperial Japanese Army during the Second Sino-Japanese War, the Battles of Khalkhin Gol against theSoviet Union, and the Second World War. It was the most widely produced Japanese medium tank of World War II, although the armor protection was average for a 1930s tank. The 57 mm main gun, designed forinfantry support, was a carry over from the 1933 Type 89 medium tank. Later it was replaced by a 47 mm gun that was more effective against armor. The 170 hp Mitsubishi engine was a capable tank engine in 1938, and – notably for the time – it was an air cooled diesel. After 1941, the tank was less effective than most Allied tank designs.
The Type 97's low silhouette and semicircular radio antenna on the turret distinguished the tank from its contemporaries. The suspension was derived from the Type 95 Ha-Go light tank, but used six road wheels instead of four.
History and development
With the Type 89 Chi-Ro fast becoming obsolete in the late 1930s, the Imperial Japanese Army (IJA) began a program to develop a replacement tank for infantry support. Experience during the invasion of Manchuria determined that the Type 89 was too slow to keep up with motorized infantry. The new medium tank was intended to be a scaled-up four-man version of the Type 95 Ha-Go light tank, although with a two-man turret, thicker armor, and more power to maintain performance.
The Tokyo factory of Mitsubishi Heavy Industries completed a prototype designated Chi-Ha. The second prototype was completed in June 1937. Although the requirement was for a 47 mm gun, it retained the same short-barreled 57 mm gun as the Type 89B tank.
However, at the time IJA was more interested in the lighter Chi-Ni prototype proposed by Osaka Army Arsenal, because it was less expensive and had the same 57 mm gun.
The Second Sino-Japanese War broke out on 7 July 1937. Peacetime budgetary limitations were removed, and the more expensive Mitsubishi Chi-Ha model was accepted as a new Type 97 medium tank.
Japanese tank designations
Chi (チ) came from Chū-sensha (チュウセンシャ, "medium tank"). Ha and Ni, in Japanese army nomenclature, refer to model number 3 and 4, respectively from old Japanese alphabet iroha. The Type was numbered 97 as an abbreviation of the imperial year 2597, corresponding to the year 1937 in the standard Gregorian calendar. Therefore, the name "Type 97 Chi-Ha" could be translated as "1937's medium tank model 3".
Type 97 Chi-Ha tank radio operator and vehicle Radio Set Type 96 Mark 4 Bo.
Type 97 hull was of riveted construction with the engine in the rear compartment. In the forward compartment, the driver sat on the right, and bow gunner on the left. The commander's cupola was placed atop the turret. Internal communications were by 12 push buttons in the turret, connected to 12 lights and a buzzer near the driver.
The Type 97 was initially equipped with a Type 97 57 mm main gun, the same caliber as that used for the earlier Type 89 I-Go tank. The cannon was a short-barreled weapon with a relatively low muzzle velocity, but sufficient as the tank was intended primarily for infantry support. The gun had no elevation gear.
The tank carried two 7.7 mm Type 97 machine guns, one on the front left of the hull and the other in a ball mount on the rear of the turret. The latter could not be remounted on top of the turret for anti-aircraft use.The turret was capable of full 360-degree traverse, but the main gun had a second pair of trunnions, internally allowing a maximum 10-degree traverse independently of the turret.
The thickest armor used was 50 mm on the gun mantlet and 28 mm on the hull front.
Power was provided by an air-cooled "V-12 21.7 liter diesel Mitsubishi SA12200VD" engine, which provided 170 hp (127 kW).
Development of the improved Shinhoto Chi-Ha
The shortcomings of the Type 97, with its low-velocity 57 mm gun, became clear during the 1939 Battles of Khalkhin Gol against the Soviet Union. The 45 mm gun of the Soviet BT-5 and BT-7 tanks outranged the Japanese tank gun, resulting in heavy Japanese losses. This convinced the Army of the need for a more powerful gun. Development of a new 47 mm weapon began in 1939 and was completed in 1941. The Type 1 47mm tank gun was designed specifically to counter the Soviet tanks. The 47 mm gun's longer barrel generated much higher muzzle velocity, resulting in armor penetration superior to that of the 57 mm gun. The new version, designated Type 97-Kai Shinhoto Chi-Ha, replaced the original model in production in 1942. It had a new, larger turret. (A considerable number of existing 57-mm-gun turrets were subsequently re-used in the Type 4 Ke-Nu light tank.)