"To the Chief of the 3rd Departmetn of the GAU UMT
Engineer-Major comrade Bozilenko
On the issue of trials of the ATZ-3T tractor
I inform you in this letter that the ATZ-3T tractor, designed and assembled at the ATZ on the 1TA tractor base was subjected to factory trials and drove for 400 km along various roads and mountain terrain. The tractor was assembled by means of mounting new components on an altered chassis of a prior experimental tractor. The gearbox and other transmission mechanisms, suspension, and other components were taken from an existing tractor without changed, and had already worked for 700 hours. The altered components of the tractor worked well, without breakdowns or defects, and are in good condition even now.
In the future, we plan to continue factory trials along a 500 km course, which will include obstacles.
The ATZ-3T tractor has the chassis of the armoured HTZ-16 tractor, which works reliably under heavy load, and the overall vehicle, both in layout and weigh distribution, differs little from the STZ-5 tractor, which is well studied in trials and usage.
The following changes were made to the layout of the ATZ-3T compared to the STZ-5, which improve the performance of the vehicle:
The cabin was moved backwards, as a result of which the whole engine is outside of the cabin, and all of its parts are easy to service, like on the agricultural tractor. Three men fit in the cabin, unlike 2 in the STZ-5, and there is no gases and high temperature like the in the STZ-5. Since the seat is located closer to the center of gravity, oscillations of the tractor don't shake the driver as hard as on the STZ-5, which, when coupled with the lack of gases and lower heat in the cabin improves the driver's work environment and reduces fatigue. The advantages in the ATZ-3T were achieved by removing the toolbox from the truck bed and using it all to place the crew or cargo. The truck bed has flip-up seats for 4 men near the front side. Four more can sit on the removable plank seat.
The factory's chief designer notes that, in the future, implementation of several improvements based on performed trials, including changing of the layout by means of moving the fuel tank from the front of the cabin to the rear, and lengthening the length of the contact surface, will improve the conditions for the people in the cabin and the truck bed, improve the mobility of the tractor, and reduce, compared to the STZ-5, load on the rear road wheels, which will increase the lifespan of the ball bearings.
The aforementioned changes are currently being worked on, but I nevertheless consider it possible to produce the tractor in the way that we built it and supplying the army with it, with later improvements being made after gathering experience in production and usage.
It is necessary to perform trials with the participation of GAU UMT representatives in order to accept these vehicles for service with the Red Army.
Since the vehicle has an engine, transmission, and suspension from sufficiently tested 1TA, T2G, STZ-5, and HTZ-16 tractors, and since the Red Army is desperately in need of vehicles of this type, I ask for your direction to organize trials with my participation to compose an evaluation and reach a conclusion regarding accepting the tractor into service with the Red Army.
October 15th, 1943"