Type 2 Ho-I

Experimental Type 1 gun tank Ho-I, 1941

Design work on the Type 2 Ho-I began in 1937, after experience in Manchukuo taught Japanese war planners that an armored vehicle with a larger weapon would be useful against fortified enemy positions such as pillboxes, against which the standard low-velocity 57mm and high-velocity 47mm tank guns were ineffective. Since this vehicle was to be able to keep up with the rest of an armored formation, the Japanese began work on mounting a Type 41 75 mm Mountain Gun onto the chassis of the Chi-Ha medium tank. The adapted mountain gun, known as the Type 99 75 mm Tank Gun, was completed in 1940. The gun could fire an assortment of ammunition, including a 6.6kg (14.5lb) armor-piercing shell and had a muzzle velocity of 445mps. By 1942 the Type 99 75 mm gun was fitted into a Type 97-Kai Shinhoto Chi-Ha turret, which resulted in the designated Type 2 Ho-I gun tank.[1][2] The Type 2 Ho-I gun tank was intended to be part of a fire support company in each of the tank regiments.[1]

Experimental Type 1 gun tank Ho-I, side view

Type 2 gun tank Ho-I, side view

The 1941 prototype model, known as the Experimental Type 1 Ho-I, used the Type 97 Chi-Ha chassis.[3] The production model utilized the chassis of the Type 1 Chi-He, which was itself a modified Type 97 Chi-Ha hull.[4]

The main armament of the Type 2 Ho-I was a Type 99 75 mm tank gun, and secondary armament was a single 7.7 mm Type 97 Light Machine Gun in the hull.[3] The short barreled 75 mm Type 99 Gun was mounted in a fully rotating enlarged three-man gun turret used for the Type 97 Shinhoto Chi-Ha tank.[1]

Production was hampered by material shortages, and by the bombing of Japan in World War II. All 31 Type 2 Ho-I tanks were conversions from existing Type 1 Chi He medium tanks.[1] The Tokyo factory of Mitsubishi Heavy Industries was unable to retool for mass production by the end of 1944, when the program was cancelled. These units were allocated to the Japanese home islands to defend against the projected Allied Invasion. As the cessation occurred before that invasion, the Type 2 Ho-I never saw combat.[2][3]

• Zaloga, Steven J. (2007). Japanese Tanks 1939–45. Osprey. ISBN 978-1-8460-3091-8.

• History of War.org
• Taki's Imperial Japanese Army Page - Akira Takizawa
• World War II drawings

• Foss, Christopher (2003). Great Book of Tanks: The World's Most Important Tanks from World War I to the Present Day. Zenith Press. ISBN 0-7603-1475-6.
• Foss, Christopher (2003). Tanks: The 500. Crestline. ISBN 0-7603-1500-0.