A development of the IS-1 Heavy Tank, the IS-2 had a V-2-IS engine that was capable of propelling it at speeds of up to 37 kilometers per hour. As concluded by German forces following early engagements in Romania in 1944, the IS-2 was quite slow and not nearly as maneuverable as its counterpart, the German Tiger I. However, this was met up for by the vehicle's thick armor and fantastic armament consisting of a single 122 mm D-25T main gun, two secondary DT machine guns, and a tertiary DShK machine gun in the anti-aircraft role. Because the rounds were so large, the IS-2s ammunition was made in two parts, the round and the explosive charge. This slowed reload time, but allowed one man to still be able to load the gun.
The IS-2 was a large tank, weighing in at 41 metric tons and being 9.9 meters long, 3 meters wide, and 2.7 meters tall. The vehicle's armor thickness varied, with it being 120 mm thick in the upper front portion of the hull, 90 mm in the lower, 90 mm in the sides, and 160 - 100 mm in the turret. 
Accepted into production in late 1943, 100 examples of the type were in service by the beginning of 1944.
- ↑ Listed in at least one source as the JS-2
- ↑ 1.0 1.1 Forty, George. WW1 and WW2 Tanks. Southwater Books (Anness Publishing Ltd). 2012. ISBN 1 78019 190 1 Page 59
- ↑ Zaloga, Steven J. IS-2 Heavy Tank 1944-73. Osprey Publishing (1994), Page 10
- ↑ 3.0 3.1 http://www.wwiivehicles.com/soviet-union/vehicle/heavy-tank/is-2--heavy-tank.asp