First KV-1S

 "To the Chief of the GBTU BTU, Major General of the Tank Forces, comrade Korobkov

I report that the Kirov factory presents two KV-1S tanks for trials.

First tank: #10279

1. Engine: V-2KF #A-1401 650 hp at 2100 RPM
2. Cooling system:
1. Water radiators designed for the KV-3 tank
2. Oil radiator from the RZT aircraft
3. Gearbox: 8 speed with demultiplier, blueprint 21gr
4. Main clutch: four disk, blueprint 110gr
5. Fan with stamped blades and milled diffuser, blueprint 902gr
6. Shifting gate blueprint 119gr and control rods blueprint 117gr

Second tank: #10334

1. Engine: V-2KF #4ML-1669 650 hp at 2100 RPM
2. Cooling system:
1. Water radiators: production with additional radiators - blueprint 903gr.sb.8
   
2. Production oil radiator with extra radiator, blueprint 902gr. Air intake with deflectors.
3. Gearbox: 8 speed with demultiplier, blueprint 212gr
4. Main clutch: four disk, blueprint 210gr
5. Fan blueprint 219gr
6. Shifting gate blueprint 219gr and control rods blueprint 217gr
7. Final drive blueprint 15gr (normal drive sprocket with 16 teeth)

By April 21st, 1942 trials of tank #10334 had started. It drove for 99 km on a highway. Linkage cones for 2nd, 3rd, and 4th gear control rods cut off.

Tank #10279 went on an initial run today (April 22nd) but was not accepted for trials since the air intakes on it are still wooden models.

The vehicles are not ready for checking the cooling system.

Senior Assistant to the Chief of the 5th Department of the BTU, Military Engineer 2nd Class [Signature]"

CAMD RF F.38 Op.11355 D.870 p.170