The Rare Soviet tank T -10
At the beginning of 1956 the Chief Tank Directorate of the Defense Ministry of the USSR imposed operational requirements on the heavy tank of the new generation, intended for armament in the 50s and 60s. It was directed that the vehicle should have a mass of 50-60 t and indispensable basic armament in the form of 130-mm. The technical task was given to two KB plants – Leningrad Kirov and Chelyabinsk, the Tractor Plant, and selection had to be achieved on a competitive basis.
In the 50s a complex situation occurred in the Soviet Army with heavy tanks: four models were explored in parallel. That remaining from the times of World War II, the IS -2, in spite of carrying out modernization, did not already completely satisfy the requirements of time (especially as regards protection) and over the long term befitted only the service and the re-equipment into the reinforced-concrete pillboxes; the IS -3 was characterized by low reliability, in view of which it did not enjoy popularity among the troops, and in armor it did not differ much from the medium tanks T -54.
The new tank, which was being projected for the replacement of all the above-mentioned machines, had to be deprived of the central failure of the T -10, namely weak protection and effectively fight with contemporary and promising tanks of the enemy. There was a mass of projects, about the majority of which there is no data in open access, but three tanks in 1957-1959 nevertheless reached the prototype stage: Chelyabinsk “Object 770” and the Leningrad “Object 277” and “Object 279”. But, in the difference dated 277 – further development T -10 – “Object 279” it was completely created anew, after becoming one of the most unusual and most daring projects in the history of world tanks.
Works on “Object 279” were headed by LS Troyanov, previously noted for the creation of the IS-4. “Object 279” , in contrast to the heavy-tank competitors, was intended for conducting military operations including in impenetrable locations, under conditionsof nuclear weaponry employed by the enemy. The tank had classical layout and was attended by crew of 4 people with the armored volume of 11,47 cubic meters. The machine frame represented a cast construction of four massive components, connected by welding. On the onboard housing surfaces were the diverse steel screens of curvilinear profile, which ensured additional protection. The extremely powerful front armor with a thickness of 192 mm (according to other data – 269, that it is overstated) was inclined to 60 degrees and had an angle of 45 degrees: the thickness of armor was 384-550 mm. the board of the housing 182- mm of thickness was established under a 45-degree inclination (equivalent – 260 mm). This level of protection ensured firing from any tank instrument of that time even in the nearest distances.
A similar form of housing figured in many projects of the 50s and 60s, but precisely “Object 279” brought the project to perfection. The block-cast tower was hemispherical, flattened. In contrast to “Object 277” and “770” , that had the sufficiently differentiated protection of their tower, the tower of “Object 279” had a uniform powerful armor belt on the entire perimeter with a thickness along the normal 305mm (319 according to other data) and an inclination of 30 degrees (thickness – 352 mm). At the heading angle the armor of the tower with the angle of 45-65 degrees reached 500-800 mm! As a result, “Object 279” obtained the unprecedented, record level of protection, achieved without the application of the combined armoring. The armament of the tank consisted of 130-mm gun M-65 and coupled with it 14,5- mm machine gun [KPVT]. The M-65 was developed in the second-half the 50s for the armament of new heavy tanks and anti-tank SAU. The instrument weighed 4060 kg, its length was equal to approximately 60 calibers. They were the special features of M-65 slit muzzle brake, ejector and the auxiliary scavenging stem by compressed air. The standard length of recoil – is 596-602 mm; the angles of vertical guidance – 5,5/+16 GRD. 30,7- kilogram (33 kgf, according to some accounts) armor-piercing tracer shell left stem at the speed of 1000 m/s: muzzle energy the instrument reached 15-16 MJ – it is one and a half times more, than in contemporary 120-125- mm smooth-bore guns.
The ammunition supply of the gun was partially automated: the joint efforts of the loading and cassette semiautomatic loading ensured the practical rate of fire of 5-7 shots per minute.. The more complex system [MZ] was projected, which developed a rate of fire of 10-15 V/min. However, the fire unit of “Object 279” was relatively small: 24 shots of separate loading and 300 cartridges for the machine gun. The instruments of observation and aiming were sufficiently perfect for those years included in the systems of this tank: the biplanar electrohydraulic stabilizer of “Groza” had the independent stabilization stereoscopic sight- range-finder TPD -2[s] (worked out on the experimental tank “Object 269”); night sight [TPN], combined with the instrument of IR- illumination L -2; the semiautomatic system of fire control. Many of the instruments named above appeared in the series machines only at the end of the 60’s.
For the installation into “Object 279” two Diesel engines were studied: DG -1000 with the power of 950 hp with 2500 r/min and of 2[DG]-8[M] (1000 hp with 2400 r/min). Both diesels – four-stroke, 16- drum, H-shaped, with the horizontal arrangement of cylinders (for the savings of place in the low housing) – reported to tank the running speed along the highway of 50-55 km/h with the action radius 250-300 km instead of the mechanical transmission of “Object 279” it was equipped with single-flow hydromechanical three-stage transfer. The planetary gearbox was partially automated. The undercarriage did not have analogs in the domestic tank building. Its units were mounted on two frameworks (on the plural fuel reservoirs), which pass under the bottom of the tank, and included 4 caterpillar chains (of 85-90 track-links with the single closed metallic hinge and the developed cleats), 24 single road wheels (with the internal amortization and the steel rims) during the adjustable hydropneumatic suspension – on 6 to each catepillar propeller, 12 small supporting rollers of similar construction, 4 sloths and 4 drive wheels.
Thus the actual absence of clearance was reached , the impossibility of alighting on land and extremely low specific pressure – 0,6 kg/sq. cm. Auxiliary equipment included a radio station R -113, thermo-smoke equipment, system RKHBZ and PPO. According to the results of the tests of “Object 279” , that took place in 1959 a number of serious deficiencies appeared in the undercarriage. Thus, the device entailed low nimbleness, losses of efficiency during motion on swampy grounds, complex repair and maintenance, the labor expense for production and the impossibility of reduction in the overall height of the tank. At that moment it became already clear that “Object 279” had become narrowly specialized and was expensive from the troika of experimental heavy tanks, and so had to yield its place to 277-mu or 770-mu. But on July 22, 1960 at the demonstration of new technology on the range, N.S. Khrushchev categorically forbade method for the armament of any tanks with a mass of more than 37 t, having thus written off the entire program of heavy tanks. But although it did not receive its place in the army, “Object 279” still, up to the appearance of T-80[u], remained the most powerful tank of peacetime. Now “Object 279” is a museum piece.