Experimental Work at factory #183, January 1941

"February 4th, 1941

#87s

To the Chief of the 3rd Department of the BTU, Military Engineer 1st Class, Afonin

The following work was performed at factory #183 during January of 1941:

1. Experimental work

1. Trials of T-34 gearboxes were performed. 2 gearboxes with reduced 3rd gear ratios were installed in January. The first, with the ratio lowered by 14.6%, travelled about 550 km. The second, with a gear ratio lowered by 8%, travelled 340 km. Preliminary trials show that driving tanks with reduced gear ratios is easier than those with production gearboxes. One vehicle's gearbox had its 2nd, 3rd, and 4th gears constantly engaged, where the 3rd gear was reduced by 22.1% and 4th gear by 9.5%. Changing gears was performed using a clutch. The tank with this gearbox travelled for 400 km. In this tank it is easier to engage the third gear than on the production gearbox. No chipping of the gear teeth was observed.
2. Two new friction clutches with a higher "V" coefficient (1.8) and non-rigid cooling fan attachment are being assembled. Trials of the main clutch and gearbox is delayed by the fact that two experimental T-34s need repairs. One had its engine case burst, the other has gas penetration.
3. A flamethrower for the T-34 tank is being tested. Five outings have been made. The crude oil-kerosene mixture has a range of 65-70 meters. The flamethrower has a number of defects:
1. One fuel load lasts only for 4 shots.
2. There is no cutoff for the stream.
3. The air clearing valve leaks.
4. There were cases of ignition failure.
5. The fuel leaks.
   In this form the flamethrower cannot be installed on a production vehicle. Installing the flamethrower as is will result in a reduction of ammunition capacity and worse working conditions for the crew.
4. Assembly of heaters for the BT-7M vehicle continued. Delays occurred due to the design bureau putting out blueprints late and the mechanical workshop taking too long to produce parts. The vehicle will be assembled by February 15-20th 1941.
5. Installation of the F-34 gun in a T-34 is underway, will be complete by February 5-6th.
6. A number of cooling fans were produced and are being tested. No positive results so far.
7. A track and lantern gear type drive sprocket are being developed. Will enter trials in mid-February.
8. Trials of a new ammo rack were performed. The new ammo rack works better than the production one, but a full test of the system by firing off a full complement of shells must be performed. The factory could not perform these trials due to a lack of ammunition.
9. A new driver's hatch was being tested for comfort of driving and shell resistance. The hatch is incomparably better compared to the production one. The shell resistance needs to be improved.
10. Substitutes were tested and other issues were investigated.

2. Design bureau

1. T-34 blueprints are being worked on in accordance with State degrees.
2. A number of issues to do with the main clutch, cooling fan, tracks, observation devices, etc. were worked on.
3. A draft project for a deep modernization of the T-34 is being composed.

3. A number of experimental work is being postponed as the factory has not received its credit and there are no approved plans for experimental work in 1941.

Composed by: Military Representative of the GABTU, Military Engineer 3rd Class Baikov

Checked by: Regional Engineer of the GABTU, Military Engineer 2nd Class Kozyrev"

CAMD RF 38-11355-41 pp.134-136