Type 90 Kyū-maru

The Type 90 tank (90式戦車) is the current main battle tank (MBT) of the Japan Ground Self-Defense Force (JGSDF). It is built by Mitsubishi Heavy Industries and was designed as a replacement for all deployed Type 61s and a portion of their Type 74 tanks, and entered service in 1990. It is slated to be complemented by the Type 10 tank.

Manufacturing cost
The Type 90 has an approximate unit cost of 790 million Japanese yen or approximately 7.4 million US dollars at 2008 exchange rates.

History
After the adoption of the Type 74, the Japanese High Command was already looking for a superior, completely indigenous tank design to defeat the Soviet T-72. As a result, development of a prototype, the TK-X MBT began between 1976 and 1977. Joint development was performed by Mitsubishi Heavy Industries and leadership of TRDI (Japan Defence Agency's Technology Research and Development Institute). Major subcontractors include Japan Steel Works, Daikin Industries, Mitsubishi Electric, Fujitsu and NEC.

Requirements of the Type 90 were completed in 1980 with two prototypes, both armed with a Japanese 120 mm gun (product by Japan Steel Works Limited) firing Japanese ammunition (product by Daikin Industries Limited), completed in 1982 to 1984. Testing, improvements (Turret and half Modular type ceramic composite armour), and designs were modified and constructed until 1986.

A second series of four prototypes was built between 1986 and 1988 which incorporated changes as a result of trials with the first two prototypes. These were armed with the Rheinmetall 120 mm smoothbore gun also fitted to the German Leopard 2 and, in a modified version, in the US M1A1/M1A2 Abrams MBT.

These second prototypes were used for development and then user trials, all of which were completed by 1989, before Japan formally acknowledged the Type 90 in 1990.

With the exception of the 120 mm smoothbore gun, which is made under licence from Rheinmetall of Germany, the Type 90 and its subsystems are all designed and built in Japan.

Armament
The Type 90 mounts a licensed copy of the German Rheinmetall L44 120 mm smoothbore cannon product by Japan Steel Works Limited. This is the same gun that is mounted on the German Leopard 2, American Abrams, and the South Korean K1A1 tanks. Before Rheinmetall's gun was selected, Japan has successfully produced a domestic version of the 120 mm smoothbore for testing, but the lower cost of the Rheinmetall's gave it an advantage over the domestic version.

Since its introduction, there have been several upgrades to the fire-control system including the addition of a Yttrium-Aluminium-Garnet laser rangefinder with a range of 300 to 5,000 meters, a 32-bit ballistics analysis computer, an improved thermal imaging systems and Automated-tracking systems as well as improved gun stabilization. The FCS also has an automated tracking systems and is capable of engaging moving or stationary targets while moving at day and night. The automatic target tracking system uses a thermal image display which can be controlled by either the tank gunner or commander. It is capable of tracking soldiers, vehicles and helicopters. The targeting computer can also calculate lead on moving targets.

The commander's sight consists of a 3× / 10× (day-only sight). The sight can track vertically from −29 to +29 degrees, as well as track horizontally through 180 degrees. The gunners sight has a 10 x zoom.

The gun is armed and loaded through a mechanical bustle autoloader, developed by Mitsubishi of Japan. This design allows the tank crew to operate without a loader, which allows the use of a smaller turret. The autoloading can reload in around two seconds, and the practical auto-loading and firing cycle for one target will be around 4–6 seconds.

Mounted in front of the gunner's hatch on the turret is the ubiquitous Browning M2 machine gun, manufactured under license by Sumitomo Heavy Industries, part of the Sumitomo Group. In addition to the .50-caliber machine gun is a Japanese-built 7.62 mm machine gun mounted coaxially to the left of the main gun.

Armor
The profile of the Type 90 is similar to the original German Leopard 2 without the sloped armor, (Leopard 2 to 2A4) but unlike the Leopard 2, the Type 90 uses modular ceramic and steel composite armor, common in contemporary post-1990s tank designs. The adoption of modular composite armor design facilitates the upgrading and exchange of the armor, and its frontal armor is tested to be effective against JM-33 120 mm APFSDS projectiles from the L44 gun, while the side armor of the turret is capable of defeating up to 35 mm APDS (Armor penetration of 90 millimeters of RHA at one kilometer) projectiles.

The Type 90 is smaller than most main battle tanks with a height of 2.33 meters, a width of 3.33 meters, and weighing in at 50.2 tonnes. It was designed with a distinctive low-slung turret with boxy, vertical sides and a long overhanging bustle. In comparison, the Leopard 2A4's dimensions are 2.48 meters high and 3.70 meters with a weight of 55.2 tonnes.

Mobility
The Powerpack of the Type 90 tank has the Mitsubishi 10ZG32WT 10 cylinder two stroke cycle diesel engine providing 1500 hp, coupled with Mitsubishi MT1500 automatic transmission (forward gears 4, reverse gears 2), manufactured by Mitsubishi Heavy Industries (designated 10ZG32WT, MT1500). The development of the 10ZG32WT prototype was started in 1972 and was finished in 1982. It can attain a top output of 1,120 kW (1,500 horsepower).

The hydropneumatic suspension units are mounted on the front and rear pair of road wheels, which can be adjusted on-the-fly to deal with uneven terrain, a requirement on Japan's rough, mountainous terrain.

According to the Japanese Ministry of Defense official data report, the acceleration of the type is 0–200 m in 20 seconds.

Operators

 * 🇯🇵: 341 (2010)