History of Type74

The history of Type74

Type61 which deployment started in 1961 has had a delay from a world level 3 years later. The HQ ordered to Mitsubishi engineers by a formal request about the next tank in 1963.
That outline.
1. It arms with 105mm gun.
2. Weight is less than 35ton. (It was limit weight of a Japanese railway transport freight train. But the result became 38t finally).
3. It carries strong new engine.
But, The HQ hesitated about a new tank until 1964 whether it was a remodeling Type61 tank or a complete new design tank. On balance, the HQ indicated a policy to design a new tank from the basics anew in 1965. This year was a substantial start of Type74 development.
A 105mm gun NATO standard of those days was adopted. Because this gun was recognized as an excellent gun already in the world, the HQ did not hesitate. But, Gun breech was done domestic production of. That reason is because small one were needed by a limit of interior decoration space.
All essential points of this new tank were decided in December, 1965. The hydraulic pressure position control system and Laser range finder etc were added to request in addition to 3 clauses mentioned above. And advanced computer was equipped with for FCS (Fire Control System) for the first time in the world.

Power Unit

As for the engine development, a study was begun in 1956. (That is to say, it is before than Type61 tank's deployment).
The first prototype engine was completed in 1960. (Type 4ZE,4 cylinder 200HP engine).
Engineers put some trial manufacture after that, and the last manufacturing type was completed in 1967. (Type 10ZE, 600HP engine).

1. Prototype 4ZE engine
2. Drive unit (coaxial gearing & shift)
3.10ZF engine
4. The 10ZF engine which did a power experiment in a water tank.

Gun

They adopted L7 series 105mm gun as standard of the west world in those days. But Gun Breech is domestic production. As for it, they needed more compact one in order to secure crews space of the turret inside. The ammunition loading was machine system at first, but the manufacturing type was changed in human power, because they took precedence for inside space.

Gun breech

L7 105mm gun

The test vehicle "STT"

STT was built for a test of hydraulic pressure suspension in 1966. Type61's engine was carried in first STT, because the new engine was not completed yet. As for the first test vehicle, trouble appeared one after another in a hydraulic pressure control system. In fact, Swedish Strv.103 had the hydraulic position control system as a practical use tank first in the world. But, Mitsubishi engineers couldn't refer to it, because it didn't exist yet when they began development of Type74. They made trial and error by an own effort, and completed this system.
STT which carried a new engine was built in 1967. It showed a good result, because a lot of malfunction was improved. A trial turret was carried on this STT, and a firing test was done. The various test by this STT was executed until 1969.

The Mock-Up

This Mock-up was built March 1968.
As for this model, interior was perfectly built in addition to the outside.
It was examined the outside (An effect to slide bullets on Armour.. etc) and interior (An inspection, A gun operation, A bullet load...etc) decoration on this model.

The 1st prototype

The 1st prototype was 2 tanks (STB1, STB2) built.

STB1 built first carried a wireless remote controller AA machine gun. Notice to a difference of turret shape with manufacturing type. STB1 was started a mobility test in June, 1969. A lot of practical use tests were done until September, 1970. This STB1 was introduced toward the press in October, 1970. After that, This tank participated in a JGSDF parade, and it was shown to general citizens.

STB2 was started a mobility test in July, 1969. A lot of practical use tests were done until February, 1971. This tank was not shown to general citizens.

The 2nd prototype

STB-3

STB-4

The 2nd prototype was 4 tanks (STB3, STB4, STB5, STB6) built.
As for the 2nd prototype, simplification for cost reduction and improvement of reliability were planned. For example, it is repeal of a RC machine gun, and The hydraulic pressure system of the electronic control changed in the machine control, etc...

STB3 executed a test from August 1971 to April 1973.
STB4 executed a test from September 1971. Notice a mount system change of an AA machine gun. STB5 and STB6 executed a test from October 1971 to February 1973.

In this way, All tests by prototype were finished in April 1973.
And a mass production of Typ74 was begun from the next month.

Totaled 873 Type74 was manufactured by 1990 from 1973.
It is deployed in each division of JGSDF still in the present (2002).

Type74 of manufacturing type

Modify

Type74 was executed up-grade of several times after deployment in unit.

Type74 A	Early manufacturing model.
Type74 B/C	FCS was improved. APDS-T, APFSDS-T, HEP, HEAT-T became usable. (Type74C has 2tone camouflage paint).
Type74 D	A thermal jacket was wound to a gun barrel.
Type74 E/F	FCS was improved. HEAT-MP-T became usable. Type74F mounted with a mine roller.
Type74 G	Read the following.

[Type74 G]
JGSDF tried big modifying at Type74 in 1994. Only 4 tanks received up-grade for examination.
1. The night vision device was changed in thermal image system from infrared rays system.
2. The laser detection device was added.
3.The automatic target pursuit device was added.
4.The trajectory computing machine and any electronic device were changed in digital system.
5. Ring was added to sprocket wheel for prevent tracks came off.
6. Side skirt was added. (It is detached in these pics).

But the above-mentioned clause includes guess partially, because it is not announced in these improvement officially. It is fact that this Type74G was stopped with only 4 tanks. The factor was limitation of a budget. Type74G is deployed in an education unit of Fuji now.

Family

Type74MBT has 3 kinds of families.

Type78ARV
Type78ARV development was begun in 1973 and it was deployed in 1978.
1.2.Type78ARV in halfway manufacture (Based on STB1).
More detail pics of Type78ARV

Type87AW
Type87AW development was begun in 1982 and it was deployed in 1987. It is carrying 35mm twin gun system (made in Switzerland) the same as German Gepard. A radar arrangement is different from Gepard by relation of a patent. It was updated in 1992. A late model is different in smoke discharger.
1. Type87AW early
2. Type87AW late
More detail pics of Type87AW

Type91 AVLB

Type91AVLB development was begun in 1985 and it was deployed in 1990.

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