"Report on experimental works for January-April of 1937 at plant 191 (factory #183)
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4. Trials of BT-7 vehicles with KT-26 turrets
Trials of BT-7 tanks with 76 mm guns began. The vehicle's weight increased to 13,800 kg. The first trials showed that 12 springs installed on the main friction clutch is not enough to provide reliable operation. The clutch slips on grades, turns in sand and on soft earth. Currently, the amount of springs is being increased to 16, after which trials will continue.
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6. Trials of BT-8 vehicles
Two vehicles are currently undergoing trials: one with a 45 mm gun, one with the KT-26 turret for the 76 mm gun. The BT-8 with a 45 mm gun turret travelled 450 km during trials since December of 1936, and had three cases where the fan motor broke. The motor broke and the vehicle is awaiting a new engine.
The BT-8 with a 76 mm gun turret travelled for 728 km and had two cases of fan breakage. The motor is out of action. Both vehicles had experimental motors that did not go through quality control.
Presently, a new engine that has been approved by quality control and the military representative has been received and is being installed on the BT-8. During installation it was discovered that the crankcase of the engine is leaking oil.
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