Type 1 Chi-He medium tank

The Type 1 medium tank Chi-He was an improved version of the Type 97 Chi-Ha medium tanks of the Imperial Japanese Army in World War II. It had a more powerful main gun, engine and thicker armor. It was the first Japanese tank to have a communication radio as standard equipment. Production of the tank did not begin until 1943, due to the higher priority of steel allocated to the Imperial Navy for warship construction. A total of 170 units were built. All of the tanks produced were allocated for the defense of the Japanese home islands, against the anticipated Allied Invasion. After 1941, the Imperial Japanese Army quickly realized that its 1930s designed medium tank, the Type 97 Chi-Ha, was inferior to the 1940s generation of Allied armor, such as the M4 Sherman. Since the Type 97’s low-velocity 57 mm main gun was designed for infantry support in 1938, it could not penetrate the 1940s generation of Allied armor, whereas its own thin armor made the Type 97 vulnerable to most adversaries equipped with anti-armor capabilities. In response, a new series of tanks based on an improved Type 97 design was conceived. The first of this new series was the Type 1 Chi-He. Work on the design began in 1941. However, production did not begin until 1943, due to the higher priority of steel allocated to the Imperial Navy for warship construction. A total of 170 units were built from 1943–44, and they did not see any combat. Compared to the Type 97, the Type 1 Chi-He was slightly longer and taller. Its angled, thicker frontal armor was welded, as opposed to riveted. The adding of the frontal armor and a fifth crewman increased the weight, but the "streamlining" of the hull reduced the increase to only 1.5 tons. The Mitsubishi Type 100 diesel engine at 240 hp generated 70 horsepower more than the Mitsubishi Type 97 diesel engine, and was thus more than able to compensate for the additional weight in armor. The Type 1 Chi-He's 47 mm high-velocity gun had a barrel length of 2.