The Chi-Nu did not see combat during the war. All produced units were retained for the defense of the Japanese Homeland in anticipation of an Allied invasion.
At the later stages of the war, large numbers of AmericanM4 Sherman tanks arrived at the front line and increased pressure on Japanese armored forces. The Imperial General Headquarters (大本営, Daihon'ei) decided to develop a new medium tank to counter the enemy threat as well as a replacement for the Type 97.[6]
The Army Technical Bureau had been working on the Type 4 Chi-To medium tank as the counter to the M4 Sherman, but there were problems and delays in the program. As a result, a stopgap tank was required. The Type 3 medium tank Chi-Nu was developed to cope with the M4 Sherman.[7] Development of the Type 3 Chi-Nu occurred in 1943. The low priority given to tank production meant that the Type 3 did not actually enter production until 1944, by which time raw materials were in very short supply, and in 1945 much of Japan's industrial infrastructure had been destroyed by American strategic bombing. This led to its production run being severely curtailed.[1][8] Only a total of between 144 and 166 units were produced.[1][2] The Type 3 Chi-Nu was the last tank that was fielded by the Imperial Japanese armed forces, and was still in production at the end of the war.[7]
Side view of Type 3 Chi-Nu
Design
Armor and protection
The Type 3 Chi-Nu retained the same chassis and suspension of the Type 1 Chi-He, but with the addition of an enlarged turret ring for the new large hexagonal gun turret with a commander's cupola.[3][9] It was the last design based directly on Type 97 lineage.[10] The thickest armor used was 50 mm on the front hull; it also had 25 mm on the turret, 25 mm on the sides and 20 mm on the rear deck.[4]
Type 3 Chi-Nu during assembly process, showing its transmission and partially installed controls
Armament
The main armament of the Type 3 Chi-Nu was the 75 mm Type 3 tank gun. The gun could be elevated between -10 and +25 degrees. Firing a shell at a muzzle velocity of 680 m/s (2,200 ft/s) it gave an armor penetration of 90 mm (3.5 in) at 100 m (110 yd) and 65 mm (2.6 in) at 1,000 m (1,100 yd).[11][12] Secondary armament was a 7.7 mm Type 97 machine gun.[4]
Mobility
The Chi-Nu had the same engine as the Type 1 Chi-He, producing 240 hp and a top speed of 39 km/h.[2][13]
Service record
Type 3 Chi-Nu in 1945A Type 3 Chi-Nu captured by the Americans after the surrender
The Type 3 Chi-Nu was allocated to the Japanese home islands to defend against the projected Allied Invasion. They were to be part of the "Mobile Shock Force" to be used for counter-attacks against the Allied invasion.[14] As the surrender of Japan occurred before that invasion, the Type 3 was never used in combat operations.[15] The 4th Tank Division based in Fukuoka on Kyushu had a "significant" number of the Type 3 Chi-Nu tanks produced at its depot by the end of the war.[16]
A "modification plan" for the Chi-Nu was for it to be up gunned with the Type 5 75 mm tank gun (L/56.4) and a Type 4 Chi-To turret.[17] The exact status on the progress of the Chi-Nu Kai prototype is unknown.
Foss, Christopher (2003). Great Book of Tanks: The World's Most Important Tanks from World War I to the Present Day. St. Paul, MN: Zenith Press. ISBN978-0-7603-1475-3.
