Tanks of Japan

This article deals with the history and development of tanks of the Japanese Army from their first use after World War I, into the interwar period, during World War II, the Cold War and modern era.

Overview

The validity of the tank concept was established during World War I. After the war, many nations needed to have tanks, but only a few had the industrial resources to design and build them. During and after World War I, Britain and France were the intellectual leaders in tank design, with other countries generally following and adopting their designs. Japan took interest in tanks and procured some of the foreign designs, and then went to build its own. Many Japanese designs were of tankettes and light tanks, for use in campaigns in Manchuria and elsewhere in China. During the mid-1930s, the "tank actions" there were mainly against opposing infantry as the Chinese National Revolutionary Army had only three tank battalions consisting of Vickers export tanks, German PzKpfw I light tanks, and Italian CV33 tankettes. Aside from the invasion of Malaya, and the Philippines, large-scale Japanese use of tanks was limited during the early years of the war and therefore development of newer designs were not given high priority as the Japanese strategy shifted to a "defensive orientation" after the 1941-42 victories. Armored vehicle development and fielding suffered as a result; a shift to designs with heavier armor and larger guns to fight against the larger tanks of the Allies came too late for the Japanese to field superior tanks on the battlefield.
After World War II, the Supreme Commander of the Allied Powers dismantled all military manufacturing and development facilities in Japan, causing Japan to lose the technology base required to manufacture tanks and armored vehicles. However, due to the outbreak of the Korean War, SCAP ordered Japan to re-militarize, forming the Japanese Ground-Self Defense Force and providing M4A3E8 Sherman and M24 Chaffee tanks. For various reasons, including obsolescence of the tanks in JGSDF service at the time, the JGSDF in 1954 was given the option to either purchase new American built M46 Pattons and later the M47 Patton or develop its own Main Battle Tank. The JGSDF decided to develop its own tank, which resulted in the development of the current range of modern Japanese tanks built by Mitsubishi Heavy Industries.

Naming system for tanks

Like all weapons, the year of introduction is the first criterion.
A tank's designation contains the last two digits of the Japanese imperial year, which has its origin at 660 BC. For example, the designation "Type 89" corresponds to imperial year 2589, which is 1929 in the Gregorian calendar.
However, several weapons, including tanks, might be introduced in any given year. The Japanese used ideograms to differentiate further the various weapons. The first ideogram indicated the category of the vehicle. It was a katakana syllable that corresponded to the first syllable of the category. Thus, the katakana syllable 2=ケ stood for a light tank, as it is the first syllable of the corresponding Japanese term, 2=軽戦車. Analogously, 2=チ meant a medium tank, 2=テケ a tankette, 2=ホ a self-propelled gun, and 2=カ an amphibious tank.

Abbreviation	Long form	Meaning
2=チ	2=中戦車	medium tank
2=ケ	2=軽戦車	light tank
2=ホ	2=砲戦車	gun tank
2=カ	2=水陸両用戦車	amphibious tank
2=テケ = TK	2=特殊牽引車, see Type 94 tankette	tankette
2=オ	standing for 2=超重戦車	super-heavy tank

There was a second ideogram to distinguish the models. This character is another katakana syllable that represents an ordering according to the Iroha sequence and can be thought of as a, b, c, … or first, second, third, and so on.
For example, the Type 97 Chi-Ha is a medium tank introduced in 1937 and the third medium tank, the Type 2 Ke-To is a light tank introduced in 1942 and the seventh light tank. There is sometimes a surname to supplement or replace the ideograms. The "Type 97 Shinhoto Chi-Ha" is a variation of the medium tank Chi-Ha with a new turret. The Type 95 light tank had the surname "Ha-Go" that was given by its designer, Mitsubishi Heavy Industries.

Post World War I tank designs

After World War I ended, many European countries attempted to mechanize their cavalry. The Japanese cavalry experimented with a variety of armored cars with limited success. These wheeled armored cars were not suitable for most operations in Manchuria, due to the poor road conditions and severe winter climate. Japan's army tried various methods to integrate modern armor into their traditional horse cavalry formations.
The Imperial Japanese Army obtained a variety of models from foreign sources as Japan did not have any indigenous tank production capability at that time. These models included one British Heavy Mk IV and six Medium Mark A Whippets, along with thirteen French Renault FTs, the latter subsequently designated Renault Ko-Gata Sensha. The Mk IV tank was purchased in October 1918 while the Whippets and Renaults were acquired in 1919.
The Imperial Japanese Army established an armored force in 1925. Building tanks of their own met several problems, as Japan's priority tended to be with naval procurements so production for tank steel was on a lower level. Development of the first Japanese-designed tank began in June 1925. A team of engineers participated in the development of the medium main battle tank, including a young army officer, Major Tomio Hara. Hara went on to become the head of the tank development department. The design was finished in May 1926 and the prototype was completed by February 1927. After trials, the IJA decided the Type 87 Chi-I was too heavy at 20 tons and too slow to be used as its main battle tank. When the design was rejected, a new requirement was issued for a lighter tank with a nominal weight. The new design was modeled after the Vickers Medium C, which had been bought by the IJA in March 1927. By 1929, the prototype of the Type 89 Chi-Ro was completed. As a result of trials, in 1929 the Japanese decided to develop a small vehicle for mobile operations.
Since its indigenous tank program was still in the prototype stage, in 1930 the Imperial Japanese Army purchased replacements for the Renault FTs; from France, they acquired 10 of the Renault NC1, designated Renault Otsu-Gata Sensha. The army also purchased several Vickers 6-ton tanks and six Carden Loyd tankettes from the British and used these as a basis for further development.
At first, an indigenous hybrid amphibious car known as the Sumida amphibious armored car was tested in 1930. It had both tracks and wheels and was able to drive in forward and reverse, both in the water and on land. Japanese cavalry officers were not impressed with the performance, so the amphibious car concept was abandoned. The design was changed to a land tracked vehicle only.
The initial attempt at a tracked vehicle resulted in the Type 92 Jyu-Sokosha heavy armoured car by Ishikawajima Motorcar Manufacturing Company. The Type 92 was designed for use by the cavalry for reconnaissance and infantry support. Production of this first indigenous tankette was plagued by technical problems.
The IJA determined that a new tankette was needed, so in 1933 development of the project was given to Tokyo Gas and Electric Industry. The completed 1934 experimental model was a small light tracked vehicle with a turret armed with one machine gun. The design was standardized as the Type 94 tankette, and it was designated for reconnaissance and infantry support. It entered service in 1935, but was later superseded by the Type 97 tankette. Both were "tailored" vehicles for operating in China. There the ultra-light tankettes, with weak armament and armor but highly mobile, proved very successful in infantry support and reconnaissance. However, by the late thirties, it became clear that these types of vehicles would not be very useful against a more serious armed enemy. The development of tankettes was stopped.
By 1932, Mitsubishi Heavy Industries was producing an air-cooled diesel engine that was suitable for tanks. It was placed experimentally into a Type 89. This later became known as the Type 89-B medium tank. Subsequently, Major Tomio Hara designed the suspension system, which was used on many future Japanese tanks. The bell crank scissors suspension paired bogie wheels connected by a coil spring mounted horizontally outside the hull.
Japan built the Type 95 heavy tank in 1934, which was the final version of the Japanese multi-turreted designs that had started back in 1931 with the prototype 18-ton Type 91 heavy tank. Modeled from German, Italian, and Soviet tank designs, the Type 95 featured three turrets; the main armament being a 70 mm cannon with a 6.5 mm machine gun also mounted in the main turret. The two additional turrets gave the Type 95 more firepower: one Type 94 3.7 cm tank cannon was mounted in one auxiliary turret, and the second auxiliary turret featured a 6.5 mm machine gun. Four prototypes were completed before the project was cancelled.
In the meantime, a new light tank known as the Type 95 Ha-Go was produced. Introduced in 1936, it would go on to be produced in greater numbers than any other Japanese tank. It was by no means a bad design, but its popularity among the crews delayed by a couple of years the introduction of a follower. It was already outdated in 1941. The two models that replaced it after 1942 did address the shortcoming of the Type 95, but were still insufficient. A new follower, the Type 5 Ke-Ho would not go further than testing in 1945.
In the field of amphibious tanks, the Japanese proved more creative. The army built several prototypes before the war, but the whole enterprise was dropped by 1940. The Imperial Japanese Navy took over development of amphibious vehicles and in 1941 came up with the Type 2 Ka-Mi, followed in 1943 by the larger Type 3 Ka-Chi. They were adaptations of land tanks on which detachable bows and sterns were added to provide flotation. They did not play a significant role in combat. Still, in their tank programs the Japanese introduced innovations as they built their designs, including bell-crank suspensions, as pioneers in amphibious tanks, and the use of diesel engines as they were less likely to catch on fire versus the regular gas engines.