"October 5th, 1945
Armament:
- Germany
- Gun caliber increased from 37 mm to 128 mm, a factor of 3.5.
- Muzzle velocity increased from 720 m/s to 1000 m/s, a factor of 1.4.
- Magazine fed machine guns were replaced with belt fed ones.
- AA protection at the start of the war was limited to the MG 34 7.92 mm caliber machine gun. At the end of the war, the Germans began installing 20 mm autocannons on tank chassis.
- England
- Gun caliber increased from 40 mm to 93.98 mm (on the Black Prince tank), a factor of more than 2.
- Muzzle velocity remained the same. Tanks became more powerful by virtue of a larger gun caliber.
- Machine guns are unchanged.
- AA weapons are unchanged.
- America
- Gun caliber increased from 37 to 90 mm, a factor of 2.5.
- Muzzle velocity of AP shells increased from 720 m/s to 865 m/s, a factor of 1.2.
- Machine gun armament did not change in caliber, but the number of machine guns per tank was reduced from 5 to 3.
- AA protection was improved by increasing machine gun caliber from 7.62 to 12.7 mm.
Conclusion: the firepower of all nations' tanks increased both due to caliber (37-40 mm to 90-128 mm) and muzzle velocity (700 m/s to 1000 m/s).
Armour:
- Germany
- Maximum thickness of front armour grew from 50 to 250 mm, a factor of 5.
- Maximum thickness of side armour grew from 30 to 170 mm, a factor of 5.5.
- England
- Maximum thickness of front armour grew from 80 to 203 mm (Black Prince tank), a factor of 2.5.
- Maximum side armour grew from 60 to 87 mm, a factor of 1.5 times.
- America:
- Maximum thickness of front armour increased from 57 to 120 mm, a factor of 2.1.
- Maximum thickness of side armour grew from 38 to 91 mm, a factor of 2.5.
Conclusion: Armour protection increased by a factor of 2.5-5 over the course of the war.
Engines:
- Germany
- Engine power grew from 300 to 600 hp, a factor of 2.
- High octane (74-80) gasoline was used as fuel.
- By the end of the war, the Germans began experimenting with tank diesel engines.
- England
- Engine power grew from 130 to 630 hp, a factor of 5.
- Both gasoline and diesel were used as fuel. High octane gasoline (80-90) was used.
- America
- Gasoline engine power grew from 400 to 800 hp, a factor of 2.
- 370 hp (185 x 2) diesel engines entered production during the war.
- High octane (90-100) aircraft gasoline and diesel fuel were used.
Conclusion: The power of tank engines grew 2-5 times over the course of the war. The Americans moved from using radial engines to using special tank gasoline engines. They could not create a special tank diesel engine.
Transmission:
- Germany
- Gearboxes were significantly simplified over the course of the war:
- The number of gears was reduced from 10 to 6-8.
- Hydraulic gear switching was replaced with a synchronized gearbox on the Panther tank.
- Electric transmissions were used on heavy tanks and SPGs.
- Turning mechanisms were changed during the war to allow for variable turning radii.
- England
- The design of gearboxes was simplified over the course of the war. Instead of the Wilson planetary gearbox, the British moved to mechanical gearboxes with hydraulic switching.
- Steering clutches were replaced with differential steering mechanisms.
- America
- Gearboxes were improved over the course of the war. Tractor type gearboxes were replaced with automatic and hydromechanical gearboxes. There were also experiments with electric transmissions.
- No changes were made to turning mechanisms.
Conclusion: Designs of tank transmissions aim to make a tank easier and simpler to control. All tanks have either planetary turning mechanisms or a double differential.
Tank weight:
The maximum weight of all nations' tanks increased during the war.
- Germany: 24 to 165 tons, a factor of 7.
- England: 25 to 48 tons, a factor of 1.9.
- America: 27 to 60 tons, a factor of 2.2.
Conclusion: the increase of armour and armament made the tanks significantly heavier.
Conclusions:
Study of development of tanks during the war in all nations shows the following tendencies:
- Increase of the maximum weight of all types of tanks (especially the heavy type).
- Increase of firepower, both by increasing the gun caliber and the muzzle velocity.
- Increase of armour to 200 mm.
- Usage of diesel engines up to 800 hp in power.
- Improvement of tank transmissions to increase maneuverability and make driving easier.
- Improvement of AA armament.
Chief of the GBTU Tank Directorate, Engineer-Colonel Blagonravov."
CAMD RF F. 38 Op.11355 D.2725 L.35-37
Printed in Glavnoye Bronetankovoye Upravleniye Lyudi, Sobytiya, Fakty v dokumentakh, 1944-1945 p.705