today, we are going to have a detailed look at the Soviet heavy tank, Object 777.
In the first half of the 50′s, Soviet tank design bureaus were working on creating a new generation of heavy tanks, the best known of which would later become the T-10 (IS-8). There were however other projects as well – better and more powerful. The boom of the heavy tank design in the early 50′s was heavily influenced by the fact, that (according to Soviet data, anyway) the Americans were building armored vehicles en masse and were preparing new very powerful projects of both medium and heavy tanks (here, the Soviet sources list the “T43 heavy tank” as “matching the T-10 in power”).
The first proposals for the new tank were sent to the Ministry of Transport and Heavy Machinery in June 1953, describing project variants of several heavy tanks, weighing from 46 to 50 tons. During the drawing creation, these recieved the designation of Object 752 and Object 777 (the latter being the object of this article). These drawings included more powerful guns (the 122mm M62-T2 for example), new hull and turret designs, as well as suspension (using hydraulics or individual torsion bars).
These vehicles were designed by ChKZ (Chelyabinsk Kirov Plant), which also designed new powerplant for the heavy vehicles: the 850-900hp V-7 diesel. The armor was designed specifically to protect the vehicle from new types of weapons. One interesting feature of the Object 777 was the remote-controlled AA 14,5mm machinegun KVP, another was the commander’s stabilized optics (TKNS) and the design of the hull and turret, both of which were made by casting with welded bottom.
At the same time (June 1953), a 1:10 mock-up of the vehicle was created and the assembled materials were sent to the abovementioned ministry in December 1953. Despite the fact that the development continued into 1954 however, the vehicle project was rejected. The vehicle was however in the ministry report rated higher than the T-10.
Weight: 49,8 tons (decreased to 49 tons in 1954)
Heighth: 2100mm (not counting the AA MG)
Gun: 122mm M62-T2 (capable of 5 rounds per minute and accurate fire on the move)
Secondary weapons: coax 7,62mm SG-43, AAMG 14,5mm KPV
Ammunition carried: 15 AP shells, 25 HE shells, 3000 7,62mm MG rounds
Powerplant: 850hp V-7 diesel, 17 hp/t
Maximum speed: 50 km/h (later increased to 54,7)
Average speed: 30 km/h
Transmission: Planetary (7 gears) or mechanical (6 gears)
Suspension: hydraulic (later individual torsion bars)
Range (including external fuel tanks): 250 km
Radio: RTU “Yasen”
Comms: TPU-5 “Biser”
Armor – cast, both turret and hull
Hull – upper plate: 132mm at 70 degrees (later changed to 140mm at 60 degrees)
Hull – lower plate: 175mm at 40 degrees (later changed to 200mm at 30 degrees)
Hull – nose: 250mm
Hull – upper side armor: 115 at 62 degrees (later changed to 92 at 60 degrees)
Hull – lower side armor: 105mm (0 deg)
Hull – rear armor: 45 (60 deg)
Hull – bottom: 116mm
Turret – front: 195mm (52 deg)
Turret – side: 215mm (33 deg)
Turret – rear: 90mm (40 deg)
M.V.Pavlov, I.V.Pavlov – Soviet armored vehicles 1945-1965 (Отечественные бронированные машины 1945-1965 гг.)