February 25th, 1943
On the construction of experimental IS tanks
To fulfil State Committee of Defense decree #2943ss, issued on February 24th, 1943, I order that:
- The director of the Kirov factory, comrade Dlugach, director of factory #200, comrade Sherbakov, and chief engineer of the Kirov factory, comrade Kotin, produce two experimental IS tanks at the Kirov factory: one with the 122 mm gun (U-11), the other with a 76 mm gun (F-34), and provide them for proving grounds trials by March 10th, 1943.
- The GOKO decree defines the following main characteristics of the IS tanks:
- A maximum weight of 39.5 tons for the tank armed with the 122 mm U-11 gun, including ammunition, fuel, and crew.
- A maximum weight of 38.5 tons for the tank armed with the 76 mm F-34 gun, including ammunition, fuel, and crew.
- Front: 120/100 mm (cast)
- Side: 90 mm (rolled)
- Top and floor: 20 mm
- Rear: 60 mm (sloped at 45 degrees)
- Turret: 100 mm (sides)
- Maximum speed: 55 kph.
- Transmission: 8 speed gearbox, planetary turning mechanism, planetary final drives.
- Engine: 600 hp V-2K
- No less than 30 shells for the IS tank with a 122 mm gun.
- No less than 80 shells for the IS tank with a 76 mm gun.
- Crew: 4
- With a 122 mm gun: 2 (coaxial and hull)
- With a 76 mm gun: 3 (coaxial, turret rear, and hull)
- Fuel capacity: 500 kg