After assembly, the tank was broken in (before a turret was installed) over a distance of 23 kilometers.
The breaking in occurred at all gears:
- 2 km in first gear
- 3 km in second gear
- 4 km in third gear
- 5 km in fourth gear
- 5th, 6th, 7th, and 8th gears were broken in over a combined distance of 9 km
After transport from factory #100 to factory #200, the Kirov factory, and back, the tank was broken in over a distance of 12 km.
After final tuning of mechanisms, the tank was sent to factory mobility trials. Overall, during factory trials, the tank traveled 630 km, of those 571 km (over three rounds) were in regular mode and 59 were in breaking in mode.
The first round consisted of a 154 km march (of those 24 km were for breaking in) without returning to the factory.
The second round consisted of a 141 km march.
The third round consisted of a 300 km forced march without returning to the factory. The total time spent on the third round was 21 hours 25 minutes.
Mobility trials were performed over the following route: factory #100 - Sukhomesovo village - Isakovo village - Medogorodok - Poletayevo station - Cherbarkul station - and back.
The route includes dirt roads, a stone highway, and a paved highway (beaten with many potholes).
Two swampy places were forded during the route, ranging between 1 meter and 1.25 meters in depth, 5-10 meters wide. The ground was muddy and soft. The shores were gently sloped and soft. In total, the tank crossed the ford 16 times, 6 of them over the 1x5 meter region and 10 over the 1.25x10 meter region.
The trials were performed during dry sunny weather with air temperatures ranging from 20 to 30 degrees.
The roads, both dirt and paved, were heavily dusty and movement was performed at the highest possible gear (usually 7th or 8th)."