World War II Database

Contributor: C. Peter Chen

ww2dbaseThe Type 89 I-Go medium tank design was completed in 1929. Originally designed as a light tank, newly added features and equipment pushed the weight above the 10-ton mark, thus the design was re-classified as medium tank. Production began in 1931 at the newly constructed Mitsubishi Heavy Industries factory attached to the Sagami Arsenal, Japan, and they soon became the main battle tank of the Japanese Army. They were first used in combat in 1932 in the invasion of Manchuria and the First Battle of Shanghai, both in China, where they excelled in the infantry support role. Their 57-millimeter guns were capable of knocking out machine gun nests, and their armor, albeit thin, were adequate enough to stop rifle fire. In 1934, after 220 were built, the design was re-designated Type 89A I-Go Ko as a subsequent variant Type 89B I-Go Otsu entered production. When production of Type 89B ceased, 189 units were built. The Type 89B medium tanks were equipped with diesel engines instead of gasoline engines, and they were the first mass-produced diesel-engined tanks in the world. After the Second Sino-Japanese War officially began in 1937, Type 89 I-Go medium tanks continued to serve with effectiveness. In the opening phases of the Pacific War, they were deployed to British Malaya and the Philippine Islands. They were withdrawn from front line duties in 1942, but continued to serve in rear duties or as static pillboxes.

SPECIFICATIONS

Type 89A I-Go Otsu

Machinery	One Mitsubishi A6120VD 6-cylinder air-cooled diesel engine rated at 120hp
Suspension	Leaf spring
Armament	1x57mm Type 90 gun (100 rounds), 1x6.5mm Type 91 coaxial machine gun, 1x6.5mm Type 91 hull machine gun
Armor	6–17mm
Crew	4
Length	5.73 m
Width	2.13 m
Height	2.56 m
Weight	12.7 t
Speed	26 km/h
Range	170 km

Photographs