Japanese tanks of the Cold War

After the parentheses of the immediate postwar, Japan reorganized its Army as part of the Self-Defense Forces. Despite the constitutional and political limitations, the Japanese industry of armored means produced during the Cold War vehicles comparable to the European and North American counterparts.

Type 61 main battle tank

When the Army of the Japanese Self-Defense Forces was reorganized after the Second World War, all of its main equipment was of American origin, including the light tank M-24 Chaffee (470 units received) and the medium tank M-4 sherman (360 units received). However the American tanks posed a notable inconvenience: they were projected for personnel whose average size was bigger than that of the Japanese personnel. The works for the project of a new Japanese tank started in 1954 and the first prototypes were ready in 1957. They were made four different series of prototypes, denominated ST-A1, ST-A2, ST-A3 and ST-A4. This latter was selected for entering service with the denomination Type 61 main battle tank, and the production was started in the Maruko Workshops of Mitsubishi Heavy Industries. The first tanks of the production series were completed in 1962 and a total of 500 units was delivered to the Army. Despite the new main battle tank Type 74 entered service in the 1970s, the Type 61 remained in service until the year 2000.



The appearance of the Type 61 resembled that of the American equivalent M-47 Patton - which the Japanese had evaluated in small quantities in the early 1950s -, including a similar 90-millimeter cannon, but the Japanese vehicle was more compact thanks to the lesser stature of the Japanese crews. The hull was built by welding, but the glacis plate could be removed for maintenance tasks; the turret was built by casting. The driver sat on the front part to the right, whereas the rest of the crew was placed on the turret: the commander and the gunner to the right and the loader to the left. The rear part of the turret had a space for storage. The engine and the transmission were in the rear part of the hull. The Japanese have always preferred Diesel engines for the advantages that these have over gasoline engines, among them a low consumption and lesser risk of fire. The engine was turbocharged and refrigerated by air.

The suspension was of torsion bar type and included six twin road wheels on each side, with a fore drive sprocket and a rear idler, and three return rollers. The armament comprised a 90-millimeter cannon of national construction and a 7.62-millimeter coaxial machine gun. The movement of rotation and elevation of the cannon was carried by an hydraulic system or by manual controls in case of emergency. The cannon lacked a stabilization system and fire control was of mechanical type. A 12.7-millimeter Browning machine gun was mounted upon the commander's cupola for anti-aircraft defense; it could be aimed and fired from inside the turret. The vehicle could ford depths up to one meter without any preparation but there was no provision for installing a snorkel for deep fording. In the 1970s some units were fitted with infrared lights for driving and an infrared projector for night operations.

Compared to other tanks of the early 1960s, such as the Leopard I and the AMX-30, the Type 61 has an inferior cannon, but it should be kept in mind that it was projected following the Japanese requirements. The size and the weight of the tank were kept within certain dimensions to allow its transportation on railway, which in Japan meant to cross numerous narrow tunnels. Three basic variants of the Type 61 were developed. The first one is a bridgelayer, which weighs 37 tonnes, has a crew of three and carries a scissor-tipe bridge. The second one is the Type 70 recovery vehicle, whose turret was replaced by a superstructure upon which an A-shaped frame pivots to lift the tank components. It has a crew of four and weighes 35 tonnes. Its armament comprises 7.62 and 12.7-millimeter machine guns and an 81-millimeter mortar. The third one was a vehicle for Engineers, also with a crew of four and a weight of 35 tonnes.





Type 74 main battle tank

Already in the early 1960s the Japanese understood that the Type 61 would not satisfy their requirements for the 1980s, so in 1964 it was started the work for the project of a new main battle tank. The two first prototypes, known as STB-1, were finished in the late 1969 in the Maruko Workshops of Mitsubishi Heavy Industries. Other later prototypes, STB-3 and STB-6, were built as well before the vehicle were considered as valid for entering production, which happened in 1973 in the new tank factory of Mitsubishi Heavy Industries in Sagamihara. The first order was of 280 units and the vehicle has been never exported due to the policy from the Japanese Government of not effectuating sales of any kind of armament. When production ended in 1989 a total of 893 exemplars had been built and in the early 1990s the largest part of the Type 61 tanks had been replaced, being kept a few of them for instruction. As 2016 goes on the largest part of the Type 74 tanks still remains in service.

The distribution of the space in the tank is conventional, with the driver placed on the front to the left and the other three crew members on the turret. The commander and the gunner are placed to the right and the loader to the left. The armor is of conventional type but very sloped. The engine and transmission are located on the rear part. The suspension of hydropneumatic type is probably the most remarkable feature of the Type 74. It comprises five twin road wheels, a rear drive sprocket and a fore idler, without return rollers. This suspension can be regulated by the driver according to the type of terrain on which the vehicle will move. In a rocky or rough area the suspension can be adjusted to increase ground clearance, to a maximum of 65 centimeters, and in a flat terrain ground clearance can be decreased to a minimum of 20 centimeters, allowing a greater stability. By individually regulating the height on each pair of wheels the tank can be tilted up to six degrees in pitch, and by regulating the height on each side the tank can be tilted up to nine degrees on roll. This feature can be used for obtaining a tactical advantage: when the tank stands in an inverse slope, the suspension can be lowered in the fore part and raised in the rear part, which grants to the cannon a depression angle wider than normal.

The hydropneumatic suspension has been adopted as well for the successors of the Type 74, but in the time when this tank was in development this system was truly uncommon. The only contemporary tank in service that featured this type of suspension was the Swedish experimental tank Stridsvagn 103, which required this system because of it lacked a rotatory turret and had its cannon totally fixed to the hull. Other than that, the hydropneumatic suspension had been used as well in the prototypes of the North American medium tank T95, from the second half of the 1950s, and those for the German-North American project MBT-70, in development during the 1960s; but both projects were finally cancelled.

The Type 74 is armed with the British 105-millimeter rifled cannon L7A1, built in Japan under licence. This weapon was also used for the German Leopard I and the North American M-60A1. The cannon has a vertical firing arc ranging from -5 to +15 degrees and is fully stabilized in both vertical and horizontal axes. A 7.62-millimeter machine is mounted co-axially to the cannon. The fire control system includes a laser rangefinder and a ballistic computer linked to a series of long-range ambient sensors, both of national manufacture. The vehicle carries about 50 projectiles for the cannon. The prototypes had an automatic loader, but its cost was considered excessive for being installed in the series vehicles. A 12.7-millimeter machine gun for anti-aircraft defense is installed in the top of the turret. In the prototypes this weapon could be aimed and fired from inside the turret, but unfortunately this characteristic was deemed as well as too expensive for serial production. Three smoke launchers are mounted at each side of the turret. Other equipment includes infrared driving lights and an infrared projector mounted to the left of the main armament (not present in the pictures). Besides, all the tanks are fitted with an NBC system. Finally, the Type 74 can ford up to one meter without preparation and up to three meters if fitted with a snorkel.



When projecting the Type 74, the Japanese put effort into combining all the characteristics of a modern tank without exceeding the limit weight of 38 tonnes. But some important cuts were made on the development and this eventually resulted in an insatisfying project, for it was soon outclassed by the western models of latter generation, fitted with more powerful cannons and composite armor. The replacement for the Type 74 gave as result a much larger and heavier tank, which incorporated laminated multilayer armor and weighed about 50 tonnes, and required a much more powerful engine of 1500 horsepower. Its main armament was the 120-millimeter smoothbore cannon built in Germany by Rheinmetall, which had been chosen as well for the North American M1A1 Abrams. The cannon was complemented by an automatic loader and a very sophisticated fire control system. This tank was in development by Mitsubishi during twelve years and in 1986 appeared the prototype, denominated TK-X. The final tank entered limited production in 1990 (341 units were built until 2009), with the denomination Type 90, and was delivered to the troops two years later.

The appearance of the Type 90 is very similar to that of the early version of the German Leopard II. With this tank, Japan exhibited in a very convincing way its capability for building a main battle tank comparable to any other in the world. And it achieved this even if it was unable to access the vast arms market, which would greatly help to regain the development costs or enjoy the benefits of a scalable economy. Being a country which has forbidden to own offensive weapons, its Constitution forbids the sales of weapons, albeit this could change in the future. In 2016, the most modern Japanese tank is the Type 10, a fourth-generation main battle tank; its production might have reached one hundred of units so far. As tensions have been growing with China, Japan has been assuming huge expenses for enhancing its armored weapon to the highest level. But still today the Type 74 represents about a half of the whole armored weapon in Japan. Components of this veteran tank were used for the Type 75 self-propelled 155-millimeter howitzer, which entered service in 1977 and is similar in appearance to the North American M109A1, with the artillery piece installed in a fully rotatory turret.

Categories: Tanks - Cold War - 20th Century - [General] - [General]

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Website: Military History

Article submitted: 2016-09-27