Type 1 Chi-He

The Type 1 medium tank Chi-He (一式中戦車 チへ) 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 and engine and thicker armor.

History and development
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 even minimal 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, which appeared 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 much (if any) combat.

Design


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, and weighed an additional 1.5 tons.

The Mitsubishi Type 100 diesel engine at 240 hp provided 70 hp more power 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 2.250 m, a muzzle velocity of 810 m/s, and a penetration capability of 55 mm over 100 meters and 30 mm over 1,000 meters, almost double that of the Type 97s low-velocity main gun. It was more reliable and more accurate, but did require the installation of elevation gear (on the earlier Type 97 the gunner had to physically move the gun up or down on his shoulder). Despite these improvements, this gun was barely adequate against Allied armor of 1941.

The gun was placed in a three-man turret, which had space for a loader, and could be elevated and depressed between +20 and -15 degrees. This turret was retrofitted into the "Type 97 Shinhoto ("New Turret") Chi-Ha" tank, and was also used on the Type 3 Ka-Chi Amphibious Tank.

The Type 1 Chi-He was also the first Japanese tank to carry a radio as standard equipment, eliminating the need to use signal flags.

Combat record
Most of the Type 1s were allocated to the Japanese home islands to defend against the projected Allied Invasion. Records regarding deployment outside of Japan are uncertain, but it appears that some Type 1 tanks were with the IJA 2nd Division at the Battle of Leyte in the Philippines towards the closing stages of the war. Despite Type 1's superiority in terms of armor and firepower over the earlier Type 97, it still underperformed against the American M4 Sherman.

Variants

 * Type 1 Ta-Ha Self-propelled Anti-Aircraft Gun
 * A prototype version with twin 37 mm anti-aircraft guns fitted in place of the 47 mm gun was built, but did not go into production.