Military Review

Draft heavy tank "Object 777"

In the early fifties in our country several projects of creating heavy tanks. The result of these works was the beginning of serial production and operation of T-10 tanks (“Object 730”). Other projects of similar equipment for one reason or another did not receive the approval of the customer and, as a result, did not leave the stage of design work. In particular, such interesting projects as “Object 752” and “Object 777”, developed in SKB-2 of the Chelyabinsk Kirov Plant, remained on paper.

Recall that both new projects were developed taking into account important constraints, primarily related to the combat mass. Already in the late forties, it became clear that tanks with a mass over 50 t had no real prospects, and all new equipment should be lighter. Thus, in the requirements for promising heavy tanks, special attention was paid to the dimensions and weight of the structure. For example, when creating the project “Object 752”, the tank EC-3 was taken as a reference. In the case of the “777 Object”, the same reference point in terms of weight was the EC-8 (future T-10), the combat mass of which fit into the maximum allowable frame - 50 t.

Two new projects started in June 1952, in accordance with the order of the Ministry of Transport Engineering. The Chelyabinsk Kirov Plant ordered the development of a promising heavy tank that meets a number of requirements. The design was carried out by SKB-2 specialists under the guidance of M.F. Balgi At the beginning of 1953, he was replaced by PP. Isakov. Under the leadership of the new chief designer were all further work. He was also responsible for improving one of the developments at the later stages of the project.

Model of the tank with the engine air cooling

At the preliminary stages of the project, several original ideas of one kind or another were proposed, which affected the further course of work. To study and verify all the original proposals that could not be combined into one project, the heads of SKB-2 decided to simultaneously develop two variants of a heavy tank. The 752 Object and 777 Object projects were supposed to differ from each other in a number of characteristic features and even in their design approach. For example, the “752 Object” was supposed to be completed with existing units, and for the “777” project it was planned to develop several new products, including an engine and transmission.

Sketch design of two variants of the tank was completed at the end of 1952 of the year. In the future, Chelyabinsk designers continued to develop projects and, by June, 53 had completed all the main work, which allowed submitting the necessary documentation to the Ministry of Transport Engineering.

Even before the project was divided into two separate directions, an original booking approach was proposed, designed to provide a high level of protection with the lowest possible mass. For this it was proposed to use an unusual variant of differentiated booking. Instead of the "traditional" armor plates and cast parts of different shapes, installed at different angles, the prospective tank was to receive a cast hull with units of variable thickness, as well as several rolled sheets. Due to the correct combination of the thickness and shape of cast parts, it was proposed to provide a relatively high level of protection with an acceptable weight.

An important feature of the "Object 777" project was the use of new layout solutions associated with the transverse arrangement of the power plant. Due to this, the engine compartment was shortened, which allowed the tower to move back. Thanks to this it was possible to improve the balancing of the machine, as well as improve the accuracy of the fire. The rest of the layout was classic: the control compartment in the front of the hull, the fighting compartment in the center and the engine compartment in the stern.

777 Object Liquid Cooled Engine Circuit

After the division of one project into two, the development of armored hulls was carried out in different ways. In the 777 Object project, it was decided to use a package similar to the 752 Object aggregates, but with some differences. Thus, the shape and thickness of the frontal part has changed. The maximum thickness of this part was reduced to 175 mm (against mm 215 at “752 Object”), and to maintain the level of protection, the angles of its individual parts were changed. Such improvements have led to a reduction in the weight of parts without loss in the level of protection.

The hull sides with thicknesses from 50 to 115 mm were thinner in the lower part, while the thicker upper ones were located with 62-degree camber outward, ensuring that acceptable volumes remain inside the hull. The aft part of the hull also had to be equipped with a cast piece of variable thickness, but its configuration depended on the type of power plant.

The “777 Object” and “752 Object” towers were similar, but differed in armor thickness and shape. With the help of the original differentiated booking, it was possible to maintain or even improve the level of protection by reducing the thickness of the tower forehead to 195 mm. At the same time, the thickness of the boards increased to 215 mm. According to reports, such armor could withstand the hit of German 128-mm anti-tank guns.

The project "Object 777" proposed to implement several original proposals related to the power plant. The engine should not be located along the hull, as in most tanks of the time, but across. Due to this, it was possible to reduce the length of the engine compartment to 2,1-2,3 m, depending on the type of engine and cooling system. For comparison, in T-10 this parameter reached 3,5 m. It was the reduction in the length of the engine compartment that allowed the combat compartment to be moved with positive consequences for a number of characteristics.

Air cooled tank layout

In the aft compartment of the prospective tank, a diesel engine with a power of about 850-900 hp should have been located. The creation of this product was entrusted to ChKZ Engine Design Bureau, which was headed by I.Ya. Trashutin. The engine with the symbol B-7 had to be manufactured in two configurations, differing in cooling systems. One version of the engine was to be equipped with air cooling, the other - liquid. Due to the smaller dimensions, air cooling was considered the most convenient and promising.

The aft section of the 777 Object was designed to fit the proposed engines. So, in the case of air cooling in the roof of the engine compartment a large air intake of the fan was provided. At the same time, the compartment roof consisted of a horizontal front sheet (with an air intake) and an inclined stern. When using liquid cooling instead of an inclined sheet, it was planned to install a radiator, which affected the size and shape of the stern of the hull.

With the engine had to mate a new seven-speed planetary transmission. These units also had to be developed from scratch, since the use of finished products was not considered expedient due to various factors.

The undercarriage of the tank was to be equipped with seven track rollers on each side, front guides and rear drive wheels. Several options have been proposed suspension, including torsion bar, hydraulic and hydropneumatic. The balancing of the tank, the increased number of road wheels and the suspension should have ensured a smooth ride. As a result, the accuracy of the fire in motion could also increase.

Housing design

The main weapon of the advanced heavy tank was to be a threaded gun M62-T2 caliber 122 mm. This gun with a barrel length 46 calibers could use ammunition of various types of separate loading. The initial velocity of the shells ranged from 950 m / s (armor-piercing) to 1500 m / s (sub-caliber). In the fighting compartment there were several layouts on 40 shots. To save space, it was decided to abandon the loading mechanisms that were used on the "752 Object". Because of this, all operations for the maintenance of the instrument were assigned to the loader.

Inside the fighting compartment, it was possible to place the SG-43 machine gun of the 7,62 caliber, which was paired with a cannon. In addition, for protection against airborne targets, the prospective tank was to receive a KPVT anti-aircraft machine gun. One of the variants of the draft “777 Object” implied the use of a turret on the loading hatch, similar to that used on the “752 Object”. Another proposal concerned the creation of a remote-controlled installation. This unit was proposed to be mounted on the stern of the tower, and the control had to be carried out using the remote control in the fighting compartment.

The crew of a heavy tank was to consist of four people: a driver, a commander, a gunner and a loader. Like other tanks of a similar class of the time, the driver’s workplace was located inside the hull, and the rest of the crew were in the fighting compartment. In the case and the roof of the tower were provided three hatches, equipped with viewing devices.

Thanks to the new ideas associated with the layout and booking, the designers of SKB-2 managed to meet the weight requirements of the new machine. The combat mass of the “777 Object” was estimated to be 49,8 tons. Placing the turret in the center of the hull resulted in the same length of the tank with the cannon being turned back and forth - 9,8 m. The track width was 3,4 m - 2,1 m. The height of the line of fire is 1,6 m. Thus, despite the large mass, the “777 Object” turned out to be lower than the “752 Object” in the version with a swinging tower.

In June 1953, the Chelyabinsk tank builders handed over documentation on two new projects to the Ministry of Transport Engineering. In the last days of July of the same year, the Technical Department of the Ministry issued new guidelines for new projects. The development of the “752 Object” seems to have stopped, and the “777 Object” should be reworked. According to reports, industry management demanded a change in the layout of this machine, but the details of this work are unknown. The surviving information and materials on the updated project does not allow to establish exactly how the project has changed.

Tower reservation

Also at that time, work began on a prospective centrifugal air cleaner, an prototype of which was soon built and tested within the framework of the 777 Object project. In addition, several pilot suspension units based on hydraulic and hydropneumatic systems were tested. Finally, after the disposal of the Technical Directorate, the production of a new tank on the 1: 10 scale began.

At the end of December 1953, the updated project documentation was again transferred to the Ministry of Transport Engineering. The results of the new study of the project by experts are unknown. In the future, according to available data, SKB-2 of the Chelyabinsk Kirov Plant continued to work on creating a new project for some time, but it could not even bring it to the construction of an experimental armored vehicle. Roughly in 1954, all work on the “777 Object” was discontinued due to the lack of prospects.

According to available data, the creation of a promising tank stopped at the stage of refinement of the original project. Before the work was completed, Chelyabinsk specialists, as well as employees of related organizations, had time to build and test several prototypes of various equipment, as well as produce a large-scale mock-up of the tank. Construction of a full-fledged tank did not begin and, apparently, was not planned.

It can be assumed that the fate of the 777 Object project was adversely affected by its complexity associated with the use of various new components and original ideas, such as a non-standard case design, engine air cooling system, etc. Thus, the prospective tank fully complied with the requirements of the customer, but was too complex for mass production. As a result, it was decided to abandon the development of a completely new heavy tank, focusing on updating the T-10 machine, already brought to mass production.

Based on:
Pavlov M. Pavlov I. Domestic Armored Vehicles 1945-1965 // Technique and weapons, 2014. No.10
Photos used:
"Equipment and weapons",
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  1. smith7
    smith7 21 January 2016 07: 36
    It looks like the creation of this tank was similar to what the Abrams family is now. This is not good, not bad. It's just different. Judging by the further development of tank building in
    USSR, the path to abandoning the project was right in the current situation.
    1. Stormtrooper
      Stormtrooper 21 January 2016 08: 34
      I doubt that this miracle is related to Abrams. Only the forehead of the hull is similar, the power plant has never been gas turbine engine (which is for the best), and the suspension is more like American tanks from the T95E series. In general, I do not know what led you to such thoughts. Explain?
      I’m more worried about how much this miracle would cost, once, how difficult it would be to produce it (given the almost completely molded hull and turret), two, and the location of the crew and equipment in the fighting compartment (you just look at the mech. question mark!), three. Judging by the drawings of the layout of the fighting compartment, everything that is not occupied by the crew is occupied by ammunition. Plus, the tank should have turned out pretty low, and if the three tankers in the turret would have been more or less comfortable (although what the hell is comfort, when 122mm separate-shell ammunition is hung around you like curtains), then the mechanized water tanks would have to be recruited to Wider.
      1. avdkrd
        avdkrd 21 January 2016 14: 22
        Quote: Stormtrooper
        I am more concerned about how much this miracle would cost, once how difficult it would be to produce it (given the almost completely molded case and tower)

        There was no problem with casting in the USSR, casting was just used in view of the limited capabilities for the production of rolled armored steels.
    2. tchoni
      tchoni 21 January 2016 08: 45
      More likely t72. The main idea of ​​the Abrashi is to remove the bk from the battlefield, while minimizing the height ... And here the bk is in the battle ... The idea of ​​abramsy ne is “not to allow destruction”, and the idea of ​​this tank, like the T72, “to prevent penetration”
      1. avdkrd
        avdkrd 21 January 2016 14: 34
        Quote: tchoni
        The main idea of ​​the Abrashi is to remove the BK from the combat, while minimizing the height ..

        Removing the ammunition from the combat was not "the main idea of ​​Abrams, especially since the ammunition is present in the fighting compartment. Placing the main ammunition in the turret niche is rather simply traditional for the western school of tank building. unitary shots of 44) .Access to the shells is possible only after opening the armored partitions. The rest of the shots are stored in armored containers fixed in the tank hull (eight pieces), and on the turret front in front of the loader (three). The height is not the strong side of Abrams. 55 cm versus 2438 cm for the T-2230.
        1. tchoni
          tchoni 21 January 2016 15: 25
          20 cm is the height that will save the giant of thought ....
          If we compare the height and the degree of its decrease, then this should be done not in comparison with the t90, but with the m60, which Abrams should have come to replace.
          And yet, yes, the main idea of ​​the "garden house" (this is the tower of Abrashi, who does not know) was to isolate the BC from the crew. And this happened while the massive British 105 mm gun was on the tank. After replacing it with a 120 mm smoothbore, part of the bk had to be shoved into the fighting compartment.
          And the feed niche is not something racial American ... If you look, then domestic tanks starting from t26 and ending, perhaps, t-44 and early modifications of the t55 had a developed feed niche. A similar niche was had by the mass French amh13, 30, 32 and the English chivten-concerora-challengers and many other models of armored vehicles around the world ..
  2. Bredovich705
    Bredovich705 21 January 2016 11: 03
    The article is entertaining, another gap of knowledge is filled, another plus to the author!
  3. The comment was deleted.
  4. Bormanxnumx
    Bormanxnumx 21 January 2016 12: 11
    Quote: Stormtrooper

    I am more concerned about how much this miracle would cost, once how difficult it would be to produce it (given the almost completely molded case and tower)

    You don’t have to worry about this moment, the Soviet industry owned the technology of casting large-sized parts from armored steel. Cast hulls and towers were present in sufficient quantities in the projects of armored vehicles of the post-war period.
    1. Stormtrooper
      Stormtrooper 21 January 2016 12: 54
      Projects don't interest me. I am interested in mass production. What tanks were produced in the USSR in the post-war period, until the 60s? T-54, T-55, T-62, T-10, from the main one. What were these tanks cast and bulky? Only the tower. And this tank "Three Axes" was not only cast, but almost the entire hull. The Soviet industry was undoubtedly powerful and could provide the production of such machines, but they would be much more expensive than the same T-62 or T-10. Moreover, with the advent of high-penetration cumulative projectiles, all these millimeters with slopes of the 777th would have flown into the pipe along with millions of rubles spent on their production. Yes, against kinetic ammunition, such an arrangement of armor would decide very, very seriously, but the post-war cumulative weapons with their overheated breakdown would have cut this advantage in the bud.
      1. Bormanxnumx
        Bormanxnumx 21 January 2016 13: 15
        How is the comparison with the T-62, which began to be designed in 1958? When compared with foreign opponents who were in service at a given period of time, the "Three Axes" looks very confident.
        1. Stormtrooper
          Stormtrooper 22 January 2016 08: 35
          I apologize, with 62koy I went too far, with whom it does not happen. However, casting in the T-62 is the same as in the later T-54 / T-55, so, in principle, a comparison is appropriate.
          So I don’t argue that the 777th looked more than good in comparison with Western competitors, but given the complexity (as mentioned in the article, many new technological solutions were used in this project) and the crew’s comfort (or rather lack thereof), in the future, T-10 was launched into production, taking into account the experience of developing the 752nd and 777th.
  5. kam4atka
    kam4atka 21 January 2016 17: 55
    it would not be bad for banging a whole cycle about various "Objects", thanks to the author.
  6. Fidel
    Fidel 21 January 2016 20: 47
    And it’s nice that it didn’t reach production. Especially before adoption. Although the object of interest is interesting in a technical sense and yes, a cycle about, so to speak, not implemented projects would be interesting. But purely by troubles it reminded me of the tiger-panther of the Second World War. Not in such, of course, the degree of technical masturbation perfectionism as in the Fritz, but anyway ...))
  7. Fidel
    Fidel 21 January 2016 20: 50
    Kirill respect and respect.
    Like a tanker to a tanker)) hi
  8. cheguevarazhiv
    cheguevarazhiv 22 January 2016 12: 50
    Quote: tchoni
    More likely t72. The main idea of ​​the Abrashi is to remove the bk from the battlefield, while minimizing the height ... And here the bk is in the battle ... The idea of ​​abramsy ne is “not to allow destruction”, and the idea of ​​this tank, like the T72, “to prevent penetration”

    An interesting concept ... why provide for the possibility of breaking through the object? Our concept in this regard somehow looks worked out, taking into account the tasks and goals being solved.
  9. R_D_V
    R_D_V 5 February 2016 10: 24
    How many different designs of tanks were in the USSR, some probably still classified