Japanese Armour

In the Japanese language the word for battle, sen, has been combined with the word for wagon, sha, to form sensha, a tank. Japanese interest in armoured fighting vehicles can be traced back to the 1920s when the British firm of Vickers persuaded the Japanese War Ministry to buy one of the Medium C tanks which Vickers salesmen were endeavouring to sell to a number of foreign powers. In fact the Japanese had already embarked on the building of a heavy tank, but when their designers ran into trouble from lack of experience they decided to adapt foreign designs to their requirements. 

Thus in 1929 when Japan started producing her own tanks they were based on early models of the French Renault M1917, the Vickers Medium C, and the Carden-Loyd light tank Mark VI. For the most part the Japanese models closely followed the design of the originals. The Type 89A which appeared in 1929, for example, bore a strong resemblance to the original Mark C prototype which Vickers had supplied to Japan in response to their order for a Medium C three years previously. However, the Type 89A had thicker armour, only two machine guns instead of four, and a crew of four instead or the five needed in the Mark C. The Japanese tank also had a stronger suspension, but this and the additional weight of the armour resulted in a slower speed. In effect the Japanese had converted a fast light tank into an infantry support vehicle. The decision to do so was to be reflected in subsequent Japanese armoured policy up to 1945. Tanks were generally regarded as subordinate to the traditional arms, and not as an arm of decision in their own right.

In 1932 the experimental Type 89A was followed by the Type 92, a so-called 'heavy' tank (of 26 tons) whose 34 bogie wheels gave it the appearance of a giant man-made centipede. The Type 92 did not prove successful and the Japanese turned to the design of lighter armoured fighting vehicles more in keeping with their maritime strategy aimed at weaker opponents.

The first Japanese tankette came into service in 1932, and was clearly a development of the Garden Loyd series of weapon carriers. Like the thin-skinned light tank T95 which appeared in quantity three years later, the tankette was used with success against the Chinese in the Sino-Japanese war. The Chinese had no effective equipment with which to counter the Japanese armour and the fact that they frequently conceded a battle when Japanese tankettes and Type 95s appeared undoubtedly distorted Japanese views of armoured fighting vehicles. While the development of tanks and tank tactics was accelerating in Europe, Japanese technology made little advance, probably because the theatres in which they expected to fight were not suited to uninhibited tank battles. Shortly before the war in Europe, however, Japan did introduce a new tank which owed much to her own designers. This was the medium Type 97, known also as the Chi-Ha, which went into service in 1942. Developed from the Type 95, the Chi-Ha was eventually developed to carry a variety of armaments, including in one version a 150mm gun, and in another, a 300mm mortar.

By European standards the armour of the Japanese tanks was thin, but the main armament was comparable with equivalent British and American tanks so far as calibre and weight of projectile was concerned.

General Characteristics

Classification: Japanese tanks were divided into:

Tankettes 3 to 4.5 tons
Light Tanks up to 10 tons
Medium 10 to 20 tons
Heavy over 20 tons

Tanks were named after the manufacturer, and — like their other weapons and military stores — numbered by the Japanese calendar year, dates being taken from 660 BC (which was their year 00). Thus the European equivalent of a year date is found by subtracting 660.  

Turrets: were all round or oval.

Armament: In some models a machine gun was mounted in the back plate of the turret. Special machine gun compartments were often built out of the superstructure. Machine guns were seldom, if ever, mounted coaxially with the main armament.

Armour: The most heavily armoured Japanese tank of World War II was the obsolescent M2595, 27 ton heavy tank, with 35mm (1.38in) armour on the front.

This was inadequate in a tank of this weight. The Japanese generally used rolled armour with welded and riveted joints, both types of joint being commonly found in the same tank. The use of curved plates was a common feature.

Suspension: In the tankette, and the latest light and medium tanks, the Japanese used modified Carden-Loyd suspension in which the weight of the tank was supported by horizontal compression springs arranged inside tubular protective casings on each side of the hull between the bogie wheels and return rollers.

Speed: Maximum speeds were not high, but the power-weight ratios (25 for the light tank) resulted in good cross-country speeds.

Lightness: The Japanese have emphasised lightness, and track pressures were low, giving an important advantage when travelling over soft ground.

Insulation: Woven asbestos heat insulation was placed inside the hull and turret of the tankette and light tank.

Engines: The Japanese used air-cooled diesel engines.

Accommodation: By European standards crew accommodation was cramped.