"To the BTU Chief, Military Engineer 1st Class, comrade Korobkov
I report that the Kirov factory made the following decisions on the KV-3:
- The KV-3 will be based on the Object 221 with a future plan of increasing the side armour once an 850 hp engine is received.
- The armament, front, and turret armour will be increased according to State plans.
- Since the hulls of the Objects 220 and 221 are identical in dimensions, the transmission from the 220 will be installed in the KV-3 with the V-5 engine (700 hp) with the intention to replace it with an 850 hp engine.
- Trials of the V-5 engine, transmission, and KV-3 suspension will be performed on the Object 220.
To achieve this, the Object 220 will be loaded to the weight of the KV-3 (70 tons), which will reduce the clearance of the tank by 22-30 mm from twisting of the torsion bars and compression of the rubber rims.
The first trial occurred on April 12th, 1941. A leak was found in the V-5 engine crankcase through the ventilation valve. In order to prevent this, the crankcase was connected to the oil tank with a hose.
The second trial occurred on April 14th. The vehicle traveled 120 km by April 15th. The results are as follows: over roads, the 700 hp engine works satisfactorily. Off-road, it is only possible to drive in second gear. Currently (in the spring) the terrain is especially difficult to traverse and the off-road performance with this engine in the summer will be better.
The issue of the gun is still unclear. The dimensions provided by factory #92 are unsatisfactory for the Kirov factory, as a stamped turret of the required height cannot be produced by the armour factories.
Senior Military Representative of GABTU, Military Engineer 2nd Class, Bubyakin."