In 1960, an experienced heavy tank "Object 279" entered trials. It differed from other cars of its class by its unusual design and characteristic appearance. Subsequently, all this helped the tank gain wide popularity. Specific design solutions were used to enhance key performance and provide competitive advantages. And, as tests have shown, such measures have generally justified themselves - although they have led to the emergence of specific disadvantages.
Special assignment
Recall that the history of the "Object 279" began in 1955-56, when it was decided to create a promising heavy tank. According to the requirements of the army, this machine for protection and armament had to surpass the existing models and be distinguished by increased mobility for working on difficult terrains. At the same time, the combat weight was limited to 60 tons.
One of the variants of such a tank with the index "279" was developed under the leadership of L. S. Troyanov in the framework of cooperation between the Leningrad Kirov Plant and VNII-100. The design continued until 1959, and in 1960 the first prototype was brought out for testing. Two more prototypes were not completed due to changes in plans.
Unlike other heavy tanks, the Object 279 was developed from scratch and only on the basis of new original solutions. This affected its design and appearance, and also made it possible to fulfill all the customer's requirements. As a result, the tank received serious advantages over other models of domestic and foreign development.
Improved protection
Especially for the "Object 279" from scratch they developed an original armored hull and a turret with a unique level of protection for that time. The frontal projection of the tank could withstand the hit of a 122-mm armor-piercing projectile with an initial speed of 950 m / s or a 90-mm cumulative ammunition. The booking accounted for more than half of the tank's combat mass - 32 tons.
The body was welded from four large-sized cast parts of complex curved shape. A non-removable anti-cumulative screen was installed along the perimeter, giving the body a characteristic shape. The frontal part of the body had the greatest thickness - from 93 to 265 mm in different areas. Due to the bends and rational angles of inclination, the reduced thickness of the armor increased significantly, providing protection from all current and prospective angles.
The frontal and side projections of the cast turret received protection from 305 mm (bottom) to 217 mm (top); the roof was 30 mm thick with a characteristic curved shape. For additional protection, the shoulder straps of the turret were slightly sunk inside the roof of the hull. Due to this, the junction of the turret and the hull was covered from shells.
According to the general characteristics of armor protection "Object 279" is considered the best among domestic heavy tanks. In addition, in these parameters, it was not inferior to later main battle tanks, incl. with combined protection.
Firepower
The main weapon of the "Object 279" was a 130 mm M-65 rifled cannon equipped with an ejector and a muzzle brake. She could disperse an armor-piercing projectile up to 1050 m / s, which made it possible to penetrate 245 mm of armor at a distance of 2 km (meeting angle 0 °). It also provided shooting from closed positions at a distance of more than 12 km.
The means of fire control included the TPD-2S stereoscopic rangefinder sight, the TPN night sight, as well as the Groza two-plane stabilizer, which sharply increased the accuracy of fire. In the sighting complex, some automation tools were provided, which found widespread use only in later projects.
The ammunition load included only 24 rounds of separate-case loading, which was due to the small volumes inside the tank. At the same time, part of the ammunition was placed in a mechanized stowage. An electromechanical rammer was also provided. All this made it possible to bring the rate of fire to 5-7 rds / min.
As an additional weapon, a KPV heavy machine gun paired with a cannon was used. It could be used against manpower, unprotected and lightly armored vehicles. It also provided for firing for zeroing before using the gun.
Thus, the "Object 279" combined the high characteristics of the gun and a successful FCS with ample opportunities. Additional weapons were no less effective. The only drawbacks of the armament complex were the small ammunition load of the gun and the significant departure of the barrel.
Mobility issues
The experimental tank was equipped with a 1000 hp 2DG8-M diesel engine connected to a single-flow hydromechanical transmission. With the help of the latter, the power was "lowered" from the body to the drive wheels placed under the bottom. The tank received four driving wheels at once - one per track.
The original chassis was based on two longitudinal beams placed under the bottom. They were equipped with 24 road wheels (6 per track) with independent suspension. Initially, an uncontrolled hydraulic suspension was used. Then pneumatic units were manufactured and tested. Each set of rollers carried its own 81 tracks with a width of 580 mm. It is curious that the undercarriage of the Object 279, despite its complexity, weighed 10 tons and was 500 kg lighter than the undercarriage of the T-10 heavy tank.
With a specific power of 16, 7 h.p. per ton the tank "279" developed a speed of up to 55 km / h. An unusual undercarriage made it possible to reduce the specific ground pressure to 0.6 kg / cm 2 - about the same characteristics as the light tank PT-76 had. The distance between the tracks was minimal, due to which the tank did not risk catching the ground with its bottom. All this had a positive effect on the maneuverability and mobility of the tank on soils with low bearing capacity.
The mobility of the tank was increased due to the availability of equipment for underwater driving. It included several funds, incl. a manhole pipe with a height of 4.5 m for installation above the loader's hatch. With such equipment, the "Object 279" could overcome water obstacles several meters deep. Fords with a depth of 1, 2 m were crossed without preparation.
Related problems
With all its advantages, "Object 279" had a number of significant disadvantages. Some of them could complicate production and operation, while others threatened a deterioration in combat qualities. However, these factors almost did not affect the real prospects of the project.
The need to combine a high level of protection and limited weight led to a sharp reduction in the internal volume of the hull and turret - to 11.5 cubic meters. Of these, 7, 6 cubic meters were in the habitable compartments and 3, 87 - in the power compartment. All this led to difficulties in the layout of the units, and in the future could complicate the modernization of the tank. In addition, due to the dense layout, the defeat of the armored vehicle could lead to more serious consequences than in the case of other equipment.
The Object 279's weapons complex was effective and powerful, but at the same time complex and expensive. The ammunition load left much to be desired, the increase of which required a serious overhaul of the entire fighting compartment. When driving in difficult terrain, gun overrun was a problem. The muzzle was located almost 3.5 m from the nose of the hull, which threatened to stick into the ground.
The four-track undercarriage proved to be overly complex to manufacture and operate. Any maintenance of the units turned into a complex procedure requiring special equipment. During the tests, the insufficient reliability of the existing suspension was noted. Also, when driving on soft soils, excessive power losses in the propeller were observed. When turning off-road, the tracks could burrow into the ground, increasing the resistance to movement. Finally, the undercarriage was highly vulnerable to explosive devices, combined with low maintainability.
Thus, a number of characteristic advantages of the "Object 279" were accompanied by a number of significant disadvantages. Some of them could be corrected during fine-tuning, but others required a serious redesign of the entire structure. Already in 1960, some measures were taken, and soon the second and third experimental tanks with a modified design could go on tests.
However, they were not sent to the landfill. In the same 1960, the country's leadership decided to abandon the development of new heavy tanks. The future of this class of armored vehicles was in doubt, and this issue was resolved in the simplest way. The industry was ordered to develop the direction of medium tanks - a few years later this led to the emergence of the MBT class.
Demonstrator of ideas
The project with the index "279" used a number of bold and original solutions aimed at improving the main tactical and technical characteristics. Some of these ideas were subsequently developed and used in new projects. Other decisions have remained in history, incl. due to obsolescence and the emergence of more successful ones.
The greatest interest is with tz. further development and application presented solutions in the field of fire control means. The original reinforced armor design of the Object 279 was no longer used. Instead, in new projects, combined armor was used, which had a high level of protection with a limited mass. The four-track undercarriage also did not get into new projects - due to unjustified complexity.
Object 279 remained the only one of its kind. He did not go into series and did not become the basis for new technology. However, even in such a situation, this unique sample was able to influence the further development of our armored vehicles - showing the advantages of some solutions and the disadvantages of others.
