The T-60 Myyh---T64B
- Obyekt 476 with a 6TD 1000 hp (735 kW) engine which served as a model for the T-80 combat compartment.
- Obyekt 447 which featured a new fire control with a laser telemeter, and which was able to fire missiles through the gun.
- a 1V517 ballistic calculator
- a 1G21 sight with laser telemetry
- a 1B11 cross-wind sensor.
The design team was carrying on its work on new versions. Problems with the setup of the 5TDF engine occurred as the local production capacity was proven to be insufficient against a production done in three factories (Malyshev in Kharkov, Kirov in Leningrad and Uralvagonzavod).
From 1961, an alternative to the obyekt 432 was studied, with 12 V-cylinder V-45 engine : the obyekt 436. Three prototypes were tested in 1966 in the Chelyabinsk factory. The order to develop a model derived from the 434 with the same engine gave the obyekt 438, later renamed as obyekt 439. Four tanks of this type were built and tested in 1969, which showed the same mobility as the production version, but mass production was not started. They served however as a basis for the design of the T-72 engine compartment.
In the beginning of the 1970s, the design team was trying to improve the tank further. The T-64A-2M study in 1973, with its more powerful engine and its reinforced turret, served as a basis for two projects :
For the latter, the order was given to start its production under the name T-64B, as well as a derived version (which shared 95% of its components), the obyekt 437, without the missile guidance system for cost reasons. The latter was almost twice as much produced under the designation T-64B1. On September 3, 1976, the T-64B and the T-64B1 were declared good for the service, featuring the improved D-81Tm gun (2A46-2) with a 2E26M stabiliser, a 6ETs40 loader and a 1A33 fire control, including:
Its ford capacity reaches 1.8 m without equipment. The T-64B had the ability to fire the new 9M112 "Kobra" radio-guided missile (NATO code "AT-8 Songster"). The vehicle then carries 8 missiles and 28 shells. The missile control system is mounted in front of the tank leader small turret and has many changes. The T-64B1 carries only 37 shells and has 2,000 7.62 mm rounds, against 1,250 for the T-64B.
They were modernised in 1981 by the replacement of the gun by a 2A46M1, the stabiliser by a 2E42, and the mounting of a 902A "Tucha-1" smoke grenade launcher in two groups of four, on each side of the gun. Two command versions are realised, very similar to the T-64AK: the T-64BK and the T-64B1K.
The decision, in October 1979, to start the production of the 6TD engine, and its great similarity with the 5TDF engine, allowed after some study to fit it in versions B and B1, but also A and AK, yielding the new models T-64AM, T-64AKM, T-64BM and T-64BAM, entering service in 1983.
The production ended in 1987 for all versions. The total production has reached almost 13,000.
