|Type 74 Tank|
Type 74 Tank
|Type||Main battle tank|
|Place of origin||Japan|
|Designer||Mitsubishi Heavy Industries|
|Manufacturer||Mitsubishi Heavy Industries|
|Unit cost||$5.4 million|
|Mass||38 tonnes (42 short tons; 37 long tons)|
|Length||9.41 m (30 ft 10 in)|
|Width||3.18 m (10 ft 5 in)|
|Height||2.25 m (7 ft 5 in)|
|Armor||189-195 mm (7.4-7.7 in)|
|105 mm L7A3 rifled gun |
|M2HB 12.7 mm machine gun |
Type 74 7.62 mm machine gun
|Engine||Mitsubishi 10ZF Model 21, 10 cylinders diesel, 21.5 L|
750 hp (560 kW)
|300 km (190 mi)|
|Speed||53 km/h (33 mph)|
The Type 74 (74, nana-yon-shiki-sensha) is a main battle tank (MBT) of the Japan Ground Self-Defense Force (JGSDF). It was built by Mitsubishi Heavy Industries as a replacement for the earlier Type 61. It was based on the best features of a number of contemporary designs, placing it in the same class as the US M60 or German Leopard 1. Like these designs, it mounts the Royal Ordnance L7 rifled 105 mm gun. The design did not enter widespread use until 1980, by which point other Western forces had introduced more capable designs. It was followed by the heavier Type 90.
The JGSDF began studies on new tank designs with Mitsubishi in 1962, after the Type 61 had been shown to be outmatched by new Soviet tanks such as the T-62. Features from several designs were incorporated, including the controllable suspension of the US-German MBT-70 project, the hull of the Leopard 1, and a similar 105mm gun. The design included a rotating cupola for the commander, and a new autoloader for the main gun. Prior to the 1965 decision to design an entirely new tank, some technologies which would later be used in the STB-1 (first prototype) were already in development independently in Japan. The design was finalized in 1964 and various test rigs were built between 1964 and 1967.
During the development stage, engineers opted for a license on the NATO standard Royal Ordnance L7 105mm cannon. Japan only produced the barrel under licence, developing an indigenous mantlet, breech and recoil system. The full length of the cannon was 5,592 mm, for a total weight of 2,800 kg. Initially the main gun only used APDS (Armour-Piercing Discarding Sabot) and HEP (High Explosive Plastic) as its primary ammunition. Later it was modified to fire APFSDS (Armour-Piercing Fin-Stabilized Discarding Sabot) and HEAT-MP (High-Explosive Anti-Tank Multi-Purpose) shells as well.
The secondary armament consisted of a 12.7mm anti-aircraft machine gun (with 660 rounds) and a 7.62 co-axial machine gun (4500 rounds).
The Type 74 tank is powered by the Mitsubishi 10ZF Model 21 10-cylinder two-stroke cycle diesel engine providing 750 hp (560 kW). At 19 hp/tonne, its power-to-weight ratio is similar to the French AMX-30. The maximum quoted road speed of the Type 74 is 53 km/h; however, speeds of at least 60 km/h have been achieved.
Instead of composite armor (as used on the later Type 90 main battle tank), the Type 74 adopted welded steel plates for hull construction, with sloped armor extensively used to defeat armor-piercing shells and other kinetic energy penetrators. It has frontal hull armor of 80 mm with an effective armor thickness of up to 189 mm for the upper glacis and 139 mm for lower glacis. Side armor is 35 mm, while rear armor is 25 mm thick. The cast steel turret has an estimated[clarification needed] 195 mm of armor. When compared to other second generation MBTs, the Type 74 has more armor than a Leopard 1 (122mm and 140mm), but less than comparable Soviet vehicles such as the T62 (174mm and 204mm).[better source needed]
The first prototype, designated STB-1, was delivered in late 1968 and underwent a number of modifications until 1969. The autoloader proved too complex and expensive, and was removed, as was the remote controlled anti-aircraft machine gun. The overall design of the turret was also changed, becoming longer. These changes resulted in the STB-3, which was delivered in 1971. The final prototype, designated STB-6, was delivered in 1973. Production finally started as the Type 74 in September 1975, with 225 being delivered by January 1980. Production ended in 1989, with total production running to 893 examples.
In service, the tanks were updated with the addition of infra-red imagers rather than image intensifiers for the commander and gunner, and a laser rangefinder in the commander's cupola. The gunner's position included a digital fire control computer, fed range data from the commander's range finder. Rounds for the main gun were upgraded from HEP to APFSDS and HEAT-MP.
The Type 74 was considered outdated even before it entered service. The Type 90 was to have replaced it outright, but with the end of the Cold War these plans were scaled back. In 1993 four Type 74s were improved to the new Type 74 Kai (?) [Type 74 mod G (G?)] standard, adding a passive infrared camera and side skirts . The upgrade proved to be extremely expensive, and the program was abandoned.