NII-48 Experiments, 1946

"Include the following topics in the research work for 1946:

1. Production tanks and SPGs:
1. Develop armour types for:
1. Light and medium tanks and SPGs, capable of resisting 75 and 88 mm guns with the muzzle velocity of 1000 m/s.
2. For heavy tanks and SPGs, capable of resisting 88 mm guns with the muzzle velocity of 1000 m/s and 122 mm guns with the muzzle velocity of 800 m/s.
2. Improve the hull and turret of the IS-3 tank:
1. Hull:
1. Improve the connection between mudflaps and tank side.
2. Increase the robustness of the rear of the hull.
3. Increase the perpendicular robustness of the hull.
4. Increase hull floor strength.
5. Increase the hull roof strength.
2. Turret:
1. Develop reliable protection against 88 mm shells with the muzzle velocity of 1000 m/s.
2. Improve the robustness of the gun mount.
3. Strengthen the top of the turret.
4. Develop a method of protecting the turret ring from shells.
3. Put KDLVT brand steel into production for IS-3 tanks.
2. Prototypes:
1. T-54 tank
1. Determine the armour that will protect the hull and turret from 75 mm and 88 mm shells with the muzzle velocity of 1000 m/s.
2. Improve the shape of the hull from the point of view of robustness and shell resistance.
3. Improve the armour of the turret to the point that it resists shells as well as the front of the hull.
4. Develop armour screens for the T-54 to protect it from HEAT shells up to 105 mm in caliber inclusive and Faust type anti-tank rockets.
5. Develop a robust track and track pin (increase track life to 3000 km).
6. Investigate the optimal location for ammunition in the tank.
2. 701 tank
1. Determine the type of turret and hull armour that would will protect the hull and turret from 88 mm shells with the muzzle velocity of 1000 m/s and 122 mm shells with the muzzle velocity of 800 m/s.
2. Remove all weak spots revealed during gunnery trials of the 701 hull.
3. Improve the armour of the turret to the point that it resists shells as well as the front of the hull.
4. Develop armour screens for the 701 tank to protect it from HEAT shells up to 105 mm in caliber inclusive and Faust type anti-tank rockets.
5. Develop a robust track and track pin (increase track life to 3000 km).
3. Experimental work:
1. Complete research on tank armour up to [illegible] thick. Compare the resistance of heterogeneous and homogeneous armour to 75, 88, 122, 105 and 128 mm shells at angles of 0 degrees, 30 degrees, 45 degrees, and 60 degrees.
2. Develop rolled and cast armour that can protect from the following shells
   88 mm at 1000 m/s
   105 mm at 900 m/s
   122 mm at 800 m/s
   122 mm at 1000 m/s
   128 mm at 900 m/s
   128 mm at 1100 m/s
1. Homogeneous
2. Cemented
3. Surface hardened with high frequency current
4. New design
3. Develop methods of connecting tank armour up to 300 mm thick.
4. Develop methods of protecting tanks from Panzerfausts, HEAT shells, and grenades. Test these methods on medium and heavy tanks.
5. Develop methods of protecting the floor of tanks and SPGs from anti-tank mines.
6. Develop automatic welding with austenitic electrodes. 
7. Develop new types of austenitic electrodes that do not cause cracks in metal when welding.
8. Develop a quenching technology that will prevent cracks on highly hardened armour.
9. Develop steel for tank and SPG suspensions and design components to be resistant to HE and HEAT shells.
10. Develop identical technical requirements for non-armoured tank and SPG components.
11. Develop a unified method for controlling suspension raw materials.
12. Develop instructions for welding tank and SPG hulls.
13. Revisit the technical requirements for development and testing of armour during peace time.
14. Process the materials on armour and tank metallurgy retrieved from Germany and present a report with conclusions and recommendations."

CAMD RF 38-11355-3077

A few notes on this document. "Tank 701" is more commonly known as "Object 701", and eventually became the IS-4. Also, fans of comparing gun penetrations may skim over this document, but they should not. While this document doesn't mention any numbers, it mentions the protection from the 88 mm gun with the muzzle velocity of 1000 m/s (88L/71 KwK 43 in the Tiger II) as a requirement for light (what a lofty goal!) and medium vehicles, but protection from the 122 mm D-25 is already in the domain of the heavies. What a future-proofed gun the D-25 was!