Monday, 7 August 2017

Soviet Rear Turret Tanks

The idea of a rear fighting compartment was first implemented in several KV-4 projects. This concept was picked, for example, by K.I. Kuzmin, P.S. Tarapanin, and V.I. Tarotko, who took second place in the tender. Other engineers, for example, K. Buganov, picked that layout as well. It was explored several times more. In the spring of 1944, N.F. Shashmurin proposed a modernization of the IS-2. This tank had 5 crewmen, two of which were in the front, in the driver's compartment, and 3 were in the turret. The turret was in the rear of the hull, and the engine compartment was in the middle. The Object 705A, a competitor of the Object 260, took a similar shape. The rear fighting compartment layout was not unpopular among Soviet designers. However, each time the development stopped at the drawing board.

K. Buganov's KV-4 project.

The subject was kickstarted again in 1949. On February 18th, decree #701-170ss issued by the Council of Ministers of the USSR cancelled the production and development of tanks that weighed more than 50 tons. Instead, ChKZ's SKB-2 and the Chelyabinsk branch of experimental factory #100 were tasked with developing a heavy tank that weighed no more than 50 tons. This resulted in the creation of the Object 730, which was accepted into service as the T-10. The fact that this tank had a competitor is not well known. This was the K-91 heavy tank, designed at OKB IK SV under the direction of A.F. Kravtsev.

K-91 variant 2, spring 1949.

The second variant was particularly interesting. Kravtsev went further than his predecessors and put the entire crew into the turret. Several designers worked on this idea independently, as he was definitely unaware of the Chrysler K. As you can see, the driver's station could turn. The K-91 did not move past the draft stage, but the concept was adopted by several design bureaus. This is especially true for the driver's seat.

Prototype of the Object 416 SPG, Patriot Park.

In October of 1949, the factory #75 design bureau began working on a draft project of an SPG under the direction of P.P. Vasiliev. The design was presented in March of 1950. The design, indexed Object 416, was very similar to the K-91. The overall layout was similar, including the rotating driver's station. The driver remained in the front across a rather narrow arc. Unlike the K-91, this design was approved. A full-sized model was built first, then, in March of 1952, assembly of a prototype began.

The Object 430 could have been made like this. 40 mm of roof armour over the engine compartment, 2160 mm turret ring, hydroelectric controls, ground pressure of 0.77 kg/cm², 12600 kg hull, 6800 kg turret, VNII-100 AA mount, rubberized track links. From the minutes of a meeting discussing heavy and medium tank designs, March 8-10th, 1953.

Success with the Object 416 encouraged factory #75's design bureau to continue working on similar layouts, this time with the Object 430. The draft was ready in 1953 in two variants. The first was classical: engine and transmission in the rear, turret in the front, driver in the front of the hull. The second was similar to the Object 416: the crew was in the turret, which was in the rear, the engine was in the front. The more conservative version of the tank was approved. As for variant #2, it inspired the Object 430 II in World of Tanks.

Gremyakin's tank, June 1953.

In June of 1953, a draft project appeared that depicts the hero of this article. Little is known about it, only its author (Gremyakin). This was not a proposal to the department of inventions, the tank was designed in an official capacity. The overall concept was similar to what was designed by the OKB IK SV and factory #75. The armament and armour of this vehicle were the same as on heavy tanks, but it was a medium tank in size. The armament consisted of the D-25T, but that is just a placeholder. In reality, the M-62 gun would have likely been used. Like the K-91 and Object 416, the driver sat in the turret in a rotating station. The ammunition was also stored in a similar way to its predecessors. Since the tank never received an index, it is called STG (Gremyakin's medium tank) in the game.

STG in World of Tanks.

The Object 416 spelled the end of the idea of placing the whole crew into the turret. During trials, it became clear that this layout has its advantages and disadvantages, but the disadvantages triumphed. On one hand, putting the whole crew into the turret allowed better distribution of components in the hull, which also made it shorter. On the other hand, putting the driver inside the turret reduced maneuverability of fire. The range at which the driver was looking directly forward was narrow, which was unsatisfactory. After trials of the Object 416 in December of 1953, the project was closed. The same fate awaited other tanks that had the whole crew in the turret. To be fair, foreign tanks with this layout had the same problems, including the AMX ELC and MBT-70. Nevertheless, Soviet engineers returned to the idea of placing the entire crew in the turret several times, including with the Object 775.

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