Sunday 14 July 2013

T-50's Revenge: Light Tank with Heavy Armour

The idea of a well-armoured infantry tank died with the T-50. However, the need for a well-armoured infantry support tank didn't go anywhere. On July 22nd, 1943, the following document was drafted:

"Tactical-Technical Requirements for a Light Tank Project

Overall characteristics:
  1. Type: tracked, single turreted.
  2. Combat weight: 14-15 tons.
  3. Crew: 4.
  4. Dimensions: as determined by the chief engineer.
  5. Clearance: at least 400 mm.
  6. Armament: 
    1. 57 mm ZiS-4 gun or 76 mm F-34 gun in the turret, with a coaxial machinegun.
    2. Vertical angles: +25 to -5 degrees.
    3. Smoke devices: 1
  7. Ammunition capacity:
    1. 60 57 mm or 76 mm shells.
    2. 3000 rifle rounds.
    3. 20 smoke bombs.
    4. 20 F-1 grenades.
  8. Maximum highway speed: 45 kph.
    1. Average highway speed: 30 kph.
    2. Average off-road speed: 20 kph.
  9. Armour: rolled homogeneous, high hardness.
    1. Front: 45 mm, at least at 60 degrees.
    2. Side and rear: 40 mm.
    3. Roof: 20 mm.
    4. Bottom: 30-15 mm.
    5. Turret: 45 mm, with an angle of at least 30 degrees.
  10. Engine: diesel. One or two 110 hp motors.
  11. Sufficient fuel for 12 hours off-road driving.
  12. Terrain capability:
    1. Elevation and depression: up to 35 degrees.
    2. Tilt: 30 degrees.
    3. Fording depth: 1200 mm."
CAMD RF 38-11355-1394

A lot of these requirements seem familiar. The T-50 (in its later stages) was 14.5 tons, arming it with a 76 mm gun was proposed, and the speed of 45 kph was not unheard of (although with a 220 hp power pack, that may have been troublesome). 45 mm of front armour at 60 degrees is as much armour as a T-34 tank had. This tank would bring identical armour and firepower, in a smaller and cheaper package. However, these requirements did not hold for long. In November, new ones came out:

"Tactical-Technical Requirements for a Light Tank Project

Overall characteristics:

  1. Tank type: tracked.
  2. Combat weight: 20 tons.
  3. Crew: 4.
  4. Clearance: at least 400 mm.
  5. Armour: rolled homogenous, high hardness.
    1. Front: 75 mm.
    2. Side: 45 mm.
    3. Rear: 40 mm.
    4. Roof: 20 mm
    5. Bottom: 20-15 mm
    6. Turret: 60 mm
  6. Armament:
    1. 76 mm gun with AA ballistics, with a coaxial GVG machine gun (vertical range: +25 degrees to -5 degrees)
    2. GVG machine gun in the tank's front.
    3. AA machine gun in a rotating mount above the commander's cupola.
    4. 2 PPSh in storage.
    5. 1 smoke device.
  7. Ammunition:
    1. 50 76 mm shells.
    2. 3000 machine gun rounds for the GVG.
    3. 500 PPSh rounds.
    4. 20 F-1 grenades.
  8. Maximum speed: 50 kph.
  9. Terrain capability:
    1. Elevation: at least 40 degrees.
    2. Tilt: at least 30 degrees.
    3. Maximum crossable trench: 2200 mm.
    4. Maximum fording depth: 1200 mm.
  10. Engine: 300 hp
  11. Fuel tanks: at least two in the lower parts of the hull. It is forbidden to place tanks in the crew compartment."
CAMD RF 38-11355-1485

Wow, what a requirement! 75 mm of front armour is how much a KV had. This is really getting into heavy territory. The "76 mm gun with AA ballistics" is the S-54 gun meant to go in the T-34 as a stopgap measure before the T-34-85 started rolling out. Factory #174 did not disappoint, and put out a successor to the T-50.

CAMD RF 38-11355-2243

An interesting component of the design is the road wheel setup. Unlike with most designs where each wheel gets its own torsion bar, this tank's torsion bars carried a bogey with two wheels each.

But that's not all! In 1944, the requirements were inflated yet again. Most of the tank's characteristics remained the same, with the exception of the armour. The front grew to 90 mm at 62 degrees. The front of the turret, to 90 mm at 30 degrees. The sides also increased to 90 mm at 45 degrees. The armament increased to the S-53 85 mm gun. The tank's mass grew to 23 tons. At this point, the tank was easily encroaching on medium tank territory, both in mass and armament. 

Instead of making the mistake of chasing a ridiculous light tank again, factory #174 pursued the manufacture of T-34-85s. 


  1. Still, Pz.II ausf. J was best heavy light tank :D

    1. To both of you: you're stupid. especially Woras

    2. Well you're a butt.

  2. Tier V Soviet light replacement in WoT?