Few people know that it was serial, although the series was small, somewhere around 250 cars, after which it was discontinued. All the fault was the excessive weight of the car - about 60 tons.
The development of this tank began in July 1943 at the Chelyabinsk Kirov Plant under the leadership of L. Troyanov, and later - M. Balzhi. At the very beginning of 1944, the projected machine received the index "Object 701", and in March 1944 the project was submitted to the GABTU. In general, the commission liked the project, and in April of the same year it was decided to switch to the production of prototypes.
Object 701 with the S-34-I cannon.
The main idea for creating a new Soviet heavy tank was the idea of the possibility of installing more powerful artillery systems on this vehicle than those on the IS-2. Therefore, the experimental Object 701 was made at once in three versions with different guns: D-25T, C-34-II and 100-mm high-power cannon C-34-I.
Object 701 with the S-34-II cannon.
The machines were tested until the fall of 1944. And as usual, it revealed a lot of design flaws. But the vehicle also had one indisputable advantage, its 160 mm frontal armor could not be penetrated by any tank or anti-tank gun of either Soviet or German production. Of the weapon systems, the 122 m S-34-II cannon proved to be the best.
At the end of 1944, two more cars were produced, on which an upgraded transmission was installed. After testing these vehicles, it was considered that the tank was quite ready for mass production. It only remained to decide with which weapon to release it.
IS-4 in Kubinka.
Oddly enough, the C-34-II cannon was never recommended for installation in a production vehicle. The point of view won out that in order to solve the tasks that are now facing the tank forces, the 122-mm D-25T gun already mastered in production is quite enough, and for arming a new generation heavy tank, it is necessary to switch to 130 mm or even 152 mm guns (an attempt to install a 130 mm cannon was done on the IS-7).
IS-4 at a test site somewhere in the Far East.
In April 1945, the tank was put into service and put into mass production under the IS-4 designation. The hull of the vehicle was welded and the turret was cast with variable armor thickness. In addition to the aforementioned 122 mm D-25T cannon, the armament included a 12.7 mm machine gun paired with it. The same machine gun was installed as an anti-aircraft gun on the turret above the loader's hatch. One of the vehicle's features was the original ammo rack. In the IS-4, the shells were placed in special metal cassettes, which can be clearly seen in the photo. The tank had a planetary transmission, individual torsion bar suspension. The tank's crew was 4 people. The engine was powered by a V-12 diesel engine with a capacity of 750 hp. With this engine on the highway, the tank could accelerate to 43 km / h.
The ammunition rack of the IS-4 tank, metal cassettes for shells are clearly visible.
Serial production of the IS-4 continued until 1949. And basically these machines served in the Far East.
During operation, it turned out that the mass of the tank exceeded the carrying capacity of most bridges and transport platforms. It was this reason that actually buried the idea of building vehicles weighing more than 50 tons. The IS-4 was taken out of service and put into long-term storage, and then removed from service. After that, it was often used as a target at training grounds.
The driver's seat in the IS-4 tank.
The gunner's place in the IS-4 tank.
Cannon and machine gun of the IS-4 tank.
