Engineering:Obiekt 770

From HandWiki
Object 770
Obeikt 770 – Prototype Heavy Tank (23770935948).jpg
Object 770 on display at the Kubinka Tank Museum
TypeHeavy tank
Place of originSoviet Union
Production history
DesignerPavel Isakov
Designed1956
Produced1957
No. built1
Specifications
Mass55.0 t (121,300 lb)
Length10.15 m (33 ft 4 in)
Width3.38 m (11 ft 1 in)
Height2.42 m (7 ft 11 in)
Crew4

ArmourFrontal turret: 300mm RHA
Upper glacis: 120mm RHA
Lower glacis: 187mm RHA
Upper sides: 86mm RHA
Lower sides: 105mm RHA
Main
armament
130mm M-65 (37 rounds)
Secondary
armament
14.5mm KPVT machine gun (250 rounds)
Engine10-cylinder, four-stroke, DST-10 diesel engine with a supercharging compressor
1000 hp
Operational
range
200km on highway
Speed55 km/h (34 mph)

The Object 770 (Объект 770), was a prototype Soviet heavy tank designed in 1956, and was one of the last heavy tanks ever produced.[1] It was developed alongside the Object 277 and the Object 279 following the Decree of the Council of Ministers of the USSR on August 12, 1955.[2] Development was cancelled in 1960 following Nikita Khrushchev's orders to stop production of all heavy tanks weighing over 37 tons.[3][4]

History

In 1956, the GBTU (main armour directorate of the USSR) laid out the tactical and technical requirements for a new heavy tank. 3 projects would eventually emerge from this decree: The Object 277, 279 and 770. Object 277 and 279 were developed at OKBT (LKZ), the Leningrad Special-purpose Design Bureau (SKB), and Object 770 was developed at Chelyabinsk Tractor Plant. Despite having wildly different designs, the 3 vehicles were to share the 130mm M-65. Object 277's development was headed by Josef Kotin, Object 279's by L.S. Troyanov and Object 770's by Pavel Isakov.[5][4][2]

Development

Development began at Chelyabinsk in 1956, lead by P. Isakov. From the get-go, the Object 770 was intended to be designed from scratch and implement numerous advanced technologies.[1] Therefore, in 1957 a T-10M was sent to the plant to test various components.[2] It was re-equipped with a V-12 engine boosted to 985hp, as well as hydropneumatic suspension, hydromechanical transmission, control drives, final drives and tracks.[2]

One prototype was produced in 1959 and sent to testing along with the Object 277.[2][5] It proved superior to the 277 in almost all aspects, but never entered field trials due to dangerous torsional vibrations in the engine. This delayed development, which was subsequently cancelled following Khruschev's orders.

Design

The Object 770 had a fully cast design, with a dome-shaped 3 man turret (and a driver in the hull).[1][2][3] Unlike the 277 which had been based on the T-10, the 770 was completely new. However, like its cousins, the 770 carried the 130mm M-65 cannon. This was loaded with the help of an assisted loading mechanism, as the shells were too heavy to be safely and quickly loaded solely by manpower (30.7kg),[1] achieving a rate of fire of 5-7 rounds per minute.[6] The 30.7kg armour-piercing ammunition could be fired at 1050m/s, and penetrate 280mm of vertical steel at 1000m.[7] APDS ammunition (8.7kg in weight) could be fired at 1800m/s, and penetrate 350mm of vertical steel at 1000m.[7] The cannon could elevate and depress to +16° and -5° respectively.[2] The gun was fully stabilised with the "Groza" system.[1]

The Object 770 also incorporated NBC protection, an automatic fire-fighting system, thermal smoke equipment and night vision devices into its design.[3] The vehicle had hydropneumatic suspension for crew comfort and better accuracy. The tank was powered by a 10-cylinder, four-stroke, DST-10 experimental diesel engine that reached 1000hp, allowing the tank to cruise at 55 km/h.[2][8]

The tank was also very thickly armoured. The cast turret varied from 184mm to 260mm at angles from 30° to 50° from the vertical, translating to 263mm-300mm of effective armour.[2] The upper hull varied from 85-138mm from 60-71° from the vertical, equalling 261-276mm of effective protection.[1]

References

Further reading

  • Steven J. Zaloga Andrew W. Hull; David R. Markov Soviet/Russian Armor and Artillery Design Practices: 1945-1995 (Darlington Productions, 1998) ISBN: 978-1892848017
  • Kinnear, James; Sewell, Stephen 'Cookie' Soviet T-10 Heavy Tank and Variants (Osprey Publishing, 2017) ISBN:978-1-4728-2051-8