Type 74 (Nana-yon) Main Battle Tank (MBT)
The Mitsubishi-designed Type 74 Main Battle Tank.
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A joint partnership between the Japanese Ground Self-Defense Force (JGSDF) and Mitsubishi Heavy Industries in 1972 led to the development of a main battle tank to replace the aging Type 61 of 1961. For decades after the close of World War 2, the Japanese defense industry was kept on a short lease form making indigenous weapons of war, most often times stocked with US military hardware. The Type 61 was significant in that it became the first post-World War 2 tank to come out of Japan. However, by 1962, Mitsubishi Heavy Industries was already penciling a new design to counter the latest generation of Soviet tanks - namely the T-62 series - a main battle tank that was out of the scope of the existing Type 61. The design was completed in 1964 and resulted in two pilot vehicles being constructed by September of 1969 for evaluation trials.
The prototypes were designated as STB-1 and were quite conventional systems yet comparable to her contemporaries of the day. They featured the adjustable hydropneumatic suspension system of the ill-fated American/German MBT-70 as well as the basic hull design of the German Leopard I series. The vehicles were armed with the British 105mm L7 rifled main gun tied to an automatic loader and fitted to a 360-degree traversing turret assembly. The autoloader was the product of the Japan Steel Works company. The commander's cupola was fully traversable, allowing for 360-degree vantage points from the position. The 12.7mm anti-aircraft machine gun system could also be remotely operated form within the vehicle.
Limitations in these designs forced some revisions, ultimately resulting in the STB-3 prototype in 1971. The design was further evolved into the final STB-6 pilot vehicle of 1973 which was formally accepted into service by the JGSDF in 1974 to which the basic designation of "Type 74" was applied to the series. By this time the autoloader function and the remote-controlled AA gun were dropped due to production costs and a fourth crewmember - a dedicated ammunition loader - was added to the collection of operators then numbering three. Serial production of the tank began a year later and 225 examples were delivered by the beginning of 1980. In all, some 893 examples in ten major versions would be delivered to the JGSDF with production officially wrapping up in 1989.
Design of the Type 74 was highly traditional as Cold War tank designs go, in fact mimicking the look of several American Cold War tanks to come online in that span. The hull was straddled on either side by a conventional track system featuring five large road wheels with the drive sprocket at the rear and the track idler at the front and no track return rollers present. The engine was held in a rear-set compartment with the turret ahead of amidships. The crew consisted of four personnel that was made up of the driver, commander, gunner and loader. The driver sat at the front left with the commander, gunner and loader all in the turret. The commander and gunner are at the turret right with the loader to their left, operating the main gun breech as necessary. Armor protection was up to 120mm at its thickest. The turret was cast with heavily sloped sides. The main gun was protected at its base by a heavily armored, curved mantlet. There was a noticeable fume extractor on the main gun and no muzzle brake. The commander's rangefinder worked in conjunction with the digital fire control system available to the gunner for quick reactions. Aerial antennas were noted to either side of the rear turret regions. A front-mounted dozer blade became optional in later models.