"To the People's Commissar of Medium Machinebuilding, comrade Malyshev
I report that the proving grounds trials of experimental T-50 tank prototypes produced by factory #174 cannot be completed before the deadline set in your order #009ss issued on January 7th, 1941, due to a series of design defects revealed during the trials process:
The main defects of the tank are:
- Unsatisfactory lifespan of the tracks (cracks in the sockets and breaking of the teeth). Track links begin breaking after 300-400 km of travel.
- Weak design of the drive sprocket (destruction of the hub, elevated wear and cracks of the crown after 250-300 km).
- Destruction of the conical pair of gears and bending of the 3-4th gear change yoke in the gearbox after 1500 km.
- Insufficient robustness of the floor of the hull (severe vibration and 11 mm sag) and sagging of the turret platform.
- The armament and observation devices have not been installed according to the Model Commission's comments (no new turret).
- Insufficient tightness of observation device prisms (snow gets in, causes bad visibility).
- The mounting of electrical equipment is not well thought out, resulting in noise on the radio and no protection against mechanical damage to the wiring.
- Long range radio communication and telephone communication inside the tank were not thought through.
- It's difficult to switch from second gear into third.
- The temperature of the oil in the gearbox is high (100-115°C with outside temperature of -15 to -19°C)
During mobility trials, the Commission presented the factory with a list of defects that must be resolved before the proving grounds trials are complete. The factory took measures to correct these defects, but complete resolution is dragging on.
Based on the above, I ask that you:
- Order the factory to resolve all defects discovered in the design during mobility trials by February 10th and provide a sample of the new turret for ballistics trials from February 10th to 1[cut off] of this year.
- Increase the volume of trials to 2500 km for thorough checking of the components, transmission, and suspension after the new changes.
- Extend the work of the Commission until February 15th until trials and testing of communication equipment can be checked.
Deputy Chief of the ABTU, Major-General of the Technical Forces, Lebedev"