IS-3 tank

The IS-3 (Russian: Joseph Stalin) was a Soviet heavy tank of the late period of World War II, launched into serial production in its final days and did not have the opportunity to participate in the war. Therefore, this combat vehicle is often considered one of the first post-war Soviet tanks.

Due to the characteristic shapes of the upper frontal part of the hull, it received the nickname "Shchuka" (Pike).

The creation of a new heavy tank project under the provisional name "Kirovets-1" began in the late summer of 1944. The first experimental batch of IS-3 heavy tanks left the factory in May 1945.

The gun's rate of fire was 2-3 rounds per minute. The gun's ammunition load consisted of 28 separate loading shells, including 18 high explosive fragmentation rounds and 10 armor-piercing rounds. A 12.7mm DShK anti-aircraft machine gun was located on the turret roof. The range was 340 km. The IS-3 tank was in serial production until mid-1946 (in 1945, for some time, in parallel with the IS-2). IS-3 tanks were supplied to the heavy tank regiments of the Soviet Army.

In the development of the IS-3 tank project, the conclusions of the commission that investigated combat damage sustained by tanks during the Battle of Kursk were taken into account. The mass damage to the frontal elements of the hull and turret was noted. Therefore, a decision was made to work on a new turret and hull design based on the IS-2 tank to provide a more streamlined shape and sharply differentiate the armor protection.

As a result of the design work, the inclination of the welded sheets, especially in the front part of the hull, was brought to the maximum possible. Thick 120mm frontal armor plates were arranged to form a three-slope, cone-shaped, forward-protruding nose section called the "pike nose". The hatch was placed on the roof above the driver, which was not present in the IS-1 and IS-2 tanks. The need for a through-viewing slot in the frontal armor in front of the driver-mechanic was eliminated, and periscopic viewing devices were used instead. The new armor construction forms provided better anti-projectile protection. The new "flattened" turret design was later used in the IS-7, T-10, and other newer tanks.

• IS-3M is a modernized version of the IS-3.
• IS-3K is a command version of the IS-3 tank equipped with an additional R-112 radio and AB-1-P/30 charger.
• IS-3MK – a command version of the IS-3M tank with the same equipment as the IS-3K.

The IS-3 had a classic layout, with the engine and transmission department located in the aft section, the control department in the frontal section, and the combat department in the middle section. The tank's crew consisted of four people: a driver, a gunner, a loader, and a commander.

The tank hull was welded from rolled armor plates. The frontal plates of the hull were installed with a double inclination at a large angle to the vertical. The turret was cast and had a flattened spherical shape. There was a large oval hatch on the turret roof, which was covered by two covers. The loader's observation device was located on the right cover, and the commander's observation hatch was located on the left. The turret rotation mechanism was planetary, with manual and electric stepless drives. The electric drive was equipped with a commander's control system. The commander could press a button on the device to turn the turret in the desired direction along the shortest path while keeping the target in view through their observation device. The turret stopped when the line of sight coincided with the axis of the gun barrel.

The main armament of the IS-3 was the 122mm rifled tank gun D-25T, model 1943, which had a barrel length of 48 calibers / 5852mm and a muzzle velocity of 781m/s for armor-piercing shells.

The gun's ammunition consisted of 28 separate-loading shells with armor-piercing and high-explosive fragmentation armor-piercing long steel grenades. A 7.62mm DT machine gun was mounted in a coaxial mount paired with the gun. The machine gun's ammunition load was 2000 rounds: 1200 with a light bullet, 200 with an armor-piercing incendiary, and 600 with a tracer. Of these, 756 rounds were stored in 12 disc magazines of 63 rounds each, and the rest were stored in the standard plug in an uncharged magazine.

A 12.7mm anti-aircraft heavy machine gun DShK or DShKM was mounted on the circular turret mount on the turret roof, which had a circular firing range at vertical angles from -4 to +84°.

In addition, the combat crew's equipment included 25 defensive grenades F-1 or offensive RG-42 grenades, two 7.62mm submachine guns PPS-43, and 1000 rounds of ammunition for them.

The IS-3 was equipped with a V-shaped 12-cylinder four-stroke liquid-cooled diesel engine model V-11 with a power of 520 hp. The engine's fuel system included four fuel tanks with a total capacity of 425 liters.