Case for T-34 Torsion Bars

"To the Chair of the Committee of Defense at the Council of Commissars of the USSR, Marshal of the Soviet Union, comrade Voroshilov

Fulfilling the decree of the Committee of Defense #428 from November 19th, 1940, I present my thoughts on the transition to torsion bars on the T-34.

The springs (candle) on the T-34 are reliable, but have the following drawbacks:

1. The suspension shakes, which reduces the accuracy of fire on the move.
2. The wells in which the springs are housed reduce the space inside the tank, which impedes the placement of components and reduces the ammunition capacity.
3. In order to allow for movement of the vertical balancers, the side plates have cuts in them, which reduces the robustness of armour.

The torsion bars, by preliminary calculations, give:

1. A 20% increase in the volume of the fighting compartment.
2. A reduction of the suspension weight by 300-400 kg.
3. Increase in fuel capacity from 465 L to 750 L, increasing the range by 60-100 km.
4. The hull robustness is increased (due to a lack of cuts).
5. The reliability of torsion bars has been proven on the KV and T-40.
6. Factory #183 has the means to make torsion bars.

According to decree #848 issued on March 31, 1940, the width of the T-34 turret has been increased by 160 mm, and further increase without increasing the size of the turret ring does not increase the accuracy of firing.

In order to improve the combat performance of the T-34, I ask that NKSM (factory #183) produces two experimental T-34s with torsion bars, a wider turret ring, a commander's cupola, and increased speed.

I ask that you approve the project.

Marshal of the Soviet Union, G. Kulik.

January 17th, 1941"

CAMD RF 38-11355-41