June 5th, 1942
On the improvements to KV-1 tanks
The State Committee of Defense decrees that experience in using the KV-1 tank in battle revealed the following drawbacks of the KV tank:
- Its heavy weight at 47.5 tons reduces its combat value, and makes it more difficult to use.
- The gearbox is insufficiently reliable due to insufficient robustness of the first and slow gears and gearbox case.
- Insufficiently powerful cooling, as a result of which lower gears must often be used, which reduces the average speed and limits the full power of the diesel engine.
- The visibility from the tank is insufficient, due to a lack of commander's cupola and inconvenient locations of observation devices.
In order to get rid of the aforementioned drawbacks, the State Committee of Defense decrees that:
- The NKTP (comrade Malyshev), director of the Kirov factory comrade Zaltsmann, and chief designer, comrade Kotin, must ensure that as of August 1st, 1942, KV-1 tanks that weigh no more than 42.5 tons are being made.
- Allow the following measures for the NKTP (Kirov factory), Uralmash factory, and factory #200 to reduce weight to 42.5 tons:
- Reduce the thickness of side armour, LFP, and turret armour from 75 mm to 60 mm.
- Remove the driver's plate armour screen.
- Reduce the thickness of the floor to 30 mm.
- Reduce the thickness of the cast turret walls and gun mantlet to 80-85 mm, as well as reducing the volume of the cast turret, keeping the turret ring diameter.
- Reduce the track width to 650 mm.
Until August 1st of this year, NKTP and Kirov factory are allowed to produce no more than 10 47.5 KV-1 tanks per day.
- The NKTP, Kirov factory director comrade Zaltsmann, chief designer comrade Kotin, and GABTU must complete trials of the 8-speed gearbox KV tank by July 15th of this year and begin production of tanks with this gearbox on August 1st, 3 per day, starting on August 15th, 5 per day, and starting on September 1st, build only tanks with this gearbox.
- Take into account the message from Kirov factory's chief designer about defects in the existing 5-speed gearbox being removed in the following ways:
- A more robust design and stronger materials for the case.
- Improved robustness of the first and slow gears due to the use of higher quality steel.
- GABTU and comrade Fedorenko must finish replacing defective gearboxes by June 25th with improved gearboxes.
- In order to improve cooling of KV-1 tanks in high temperatures, NKTP, comrade Malyshev, director of Kirov factory, comrade Zaltsmann, and chief designer of the Kirov factory, comrade Kotin must begin production of KV-1 tanks with new finned radiators, new fans with stamped blades, and machined fan cases by July 1st, 1942.
- NKTP (director of the Kirov factory, comrade Zaltsmann) must provide GABTU with 50 finned radiators in July and 100 in August.
GABTU chief comrade Fedorenko must ensure that old fans are replaced with new ones during major repairs.
- NKTP, comrade Malyshev, director of Kirov factory, comrade Zaltsmann, and chief designer of the Kirov factory, comrade Kotin must begin production of KV-1 tanks with commander's cupolas starting from September 1st of this year.
- In order to ensure further weight reduction and increased speed of the KV-1, the NKTP (Kirov factory) is allowed to produce two KV-13 tanks according to the previous proposal:
- Mass: no more than 35 tons
- Sides: 60 mm rolled
- Front (cast): 100 mm
- Rear (cast): 80-85 mm
- Turret platform (cast): 80-85 mm
- Commander's cupola on the turret
- Highway: up to 50 kph
- Off-road: 20-25 kph
- Engine: 600 hp V2-K diesel
- Armament: 76.2 mm F-34 gun and 2 coaxial DT machineguns
- Ammunition: 60-70 76 mm shells, 2500-3000 DT rounds
- Crew: 4 (commander and also radio operator, gunner, loader, driver)
- Fuel range: 250-300 km on highway
The rest of the requirements will be confirmed by NKTP and GABTU.
- NKTP (comrade Malyshev) and Kirov factory (comrade Zaltsmann) must produce two experimental KV-13 prototypes by August 10th of this year, test them by September 10th of this year with GABTU and provide a report to GOKO regarding the trials and suggestions on producing the KV-13 at the Kirov factory by September 15th."
The rest of the decree isn't all that interesting (just shuffling around some industrial resources for the new armour), but Stalin's red pencil is at it again, and the KV-13 is crossed out for the time being.