"To Deputy People's Commissar of Defense, Lieutenant General Fedorenko
Experience in battle, especially the experience of the [91st Tank] Brigade between August 21st and 29th, 1942, shows that the KV tank lost its advantage over the T-34 in protection, as the same caliber of gun can penetrate both the KV and T-34. The KV has a significantly different weight and dimensions than the T-34, is less maneuverable, and is thus inferior to the T-34.
Difficulties in using KV tanks start at the moment of their transport. There is a constant shortage of special rail cars that can hold their weight.
As a rule, all bridges have to be bypassed on the march due to their insufficient strength. Long marches quickly disable the engine group due to significant strain and low power to weight ratio (13 hp/ton for the KV, 18 for the T-34) while the T-34 bears long marches comparatively easily.
The equipment of the KV tank is not that different from that of the T-34, their firepower is the same, therefore their effectiveness in combat is the same.
In addition to all of the above, evacuation of tanks from the battlefield and to vehicle yards is difficult and sometimes impossible due to sufficiently powerful evacuation vehicles, which leads to tanks being left in enemy hands even though it was possible (from the point of view of the flow of the battle) to evacuate them.
Conclusions:
- The KV tank is difficult to use in modern war and has equivalent effectiveness to the T-34. Using the T-34 is more rational.
- It is necessary to highlight the low vulnerability and high combat effectiveness of the T-70 tank. These tanks show high lifespans even though they are not well known.
Commander of the 91st Tank Brigade, Lieutenant-Colonel Yakubovskiy
Commissar of the 91st Tank Brigade, Regimental Commissar Timofeev"
Note: based on serial numbers of the tanks in question, the KV tank referred to here is the KV-1S.