Work on the development of a new medium tank was based on
improving the Obiekt 430 as the tank that
possessed the most compact layout of the power pack compartment and whose
main assemblies (viz. engine, transmission, steering and control, running
gear, etc.) had been sufficiently developed and practically tested during
operation of the tank.
One of the most important problems,
viz. a considerable increase of mobility characteristics of the
vehicle, was solved by fitting the tank with a 700hp forced 5TDF
engine (instead of 580 hp engine installed in the '430' tank) and
considerably reducing the tank weight down to 30.5 tonnes (instead
of 36 tonnes at the '430' tank).
At the same time, preserving all the
advantages of the '430' tank, the designing followed the directions
of obtaining higher specifications of the new tank. In order to
increase its firepower, the tank mounted a 115mm gun (U-5TC). For
the first time in the practice of the world's tank development the
tank featured an
automatic loader enabling the crew to
be cut from four to three - commander, gunner and driver, and therefore to considerably reduce the
volume of the tank fighting compartment.
These design innovations, as well as
a number of others (coaxial torsion bars, tracks with
rubber-metallic joint, height of the hull reduced by 76 mm and height of
the turret reduced by 20 mm, reduced width of the hull) led to the
creation of a new mobile tank designated the Obiekt 432. The draft
design of this tank was completed in 1960. As a result of
consideration and approval of this draft design, the Decision of the
CPSU Central Committee and the Council of Ministers of the USSR No.
141-58 was issued on February 17, 1961 about the creation of a new
medium tank at the Malyshev Plant.
In 1961 the Design Bureau prepared a
technical design of the tank called the Obiekt 432. It differed from
the draft design first of all by the enhanced protection. Use of
larger calibres for tank armament by the potential enemies,
introduction of armour-piercing sub-calibre and hollow-charge
projectiles, as well as an urgent need of biological protection of
the crew against atomic weapons determined the directions of
radically new approach to the creation of modern tank protection.
For the first time in tank building a
complex multi-layer combined protection was created at the '432' tank, consisting of armour steel, anti-cumulative jet-extinguishing
materials and special anti-radiation materials. Dramatic increase of
the protection increased the tank weight compared with the draft design up to 34 tonnes (instead of 30.5 tonnes).
The efforts of the Design Bureau on upgrading the '430'
tank resulted in a new medium tank designated '432'. This was accepted
for service with the Soviet Army under the designation of the T-64.