KV-13 (1942), smaller, not bigger

Would you like to see the KV-13 (1942) in game?
  • Yes
  • No

0 voters

How would you like to see it be introduced?
  • Tech tree
  • Premium
  • Event
  • Squadron
  • Battlepass
  • Other
  • I don’t want it

0 voters

KV-13 final config
KV-13 (1942), the first “IS-1”. On the right is the improved KV-13/IS-1, built in 1943.

The KV-13 (1942) was the first prototype in the lineage of tanks that resulted in the 85mm armed IS-1. It was the first heavy tank after the KV-1 that did not focus on being bigger, instead it was significantly smaller. But it still had better armour.

In game it would serve as a weird mix between the KV-1S and IS-1. Its armament would be the same ZiS-5 gun, while it would be extremely more mobile than both of them with at least an 18.5hp/t ratio. All while its armour would be only slightly worse than the IS-1’s. The best analogue vehicle would be the Sherman Jumbo. Great armour but a medicre gun for the BR it is placed at. It wouldn’t be nearly as impenetrable as the Jumbo, but it would have much better mobility.

Developmental history

Click for history

The KV-13 was not the first attempt at a successor to the KV-1. The first attempts at a successor to the KV-1 came in the form of the “KV-3”, a name that migrated between several designs with one common design philosophy.

Bigger = Better

These were the T-150, T-220, T-221, T-222 and T-223.

T-150, mostly just an up armoured KV-1.

T-220, now extra long!

Full scale wooden model of T-223. The behemoth that never got built.

The final of which would’ve been a 68 tonne monster with a high velocity 107mm gun, work on it was however never completed. The later prototypes already suffered greatly because of their weight still. With parts, especially those of their engines, breaking apart left and right. At the end of 1941, these plans were no longer prioritized. Partly due their issues, partly due to them being unnecessary, and partly due to the pressing need to focus on KV-1 production as the Germans were getting uncomfortably close to Moscow.

By this point (1941-1942) the KV-1, which had been a formidable opponent to the germans by the start, was showing its issues. It had begun as a 43 tonne vehicle, but was now a 48 tonne vehicle. Even it had issues with reliability and mobility. Initial attempts to fix this was split in two directions 1. Increasing its engine power and 2. decreasing its weight. Some of this work was incorporated in production vehicles, while the attempts to increase engine power was fruitless. Nonetheless, this work became the start of the KV-1S.

KV-1S September 42
KV-1S in September 1942. many of its features were implemented gradually, as such, earlier vehicles have a stronger resemblence (and performance) to the KV-1. Though the turret is a dead giveaway.

Sometime during these attempts to fix the KV-1 in early 1942, work on a completely new heavy tank began at ChKZ by the SKB-2 and Factory #100 design bureaus. Instead of the old philosphy, trying to create a bigger and heavier tank. The new tank was to weigh significantly less than the KV-1 (30 tonnes), and still possess better armour. This was the KV-13. It had the factory drawing number 233. This was not object 233, no, this preceded the GABTU index allocation. However, the later version of the vehicle would be categorised as object 233 by the GABTU. By Factory #100 it was however known as the IS-1. This was not the first use of the name, but it is the earliest use in the direct line of development that led to the IS-1.

KV-13 Draft
Drawing of the KV-13 from May, 1942.

A draft of the project was completed in May. Some design solutions were taken from the contemporary KV-1S (running gear) and some from the T-34. Its hull front was clearly inspired by SKB-2’s previous work, that of their version of the T-50 infantry support tank. This was before they were evacuated from LKZ to ChKZ. In order to not cause confusion, the T-50 that wound up in production was Factory #174’s creation, not SKB-2’s.

T-50 Kirov SKB-2
SKB-2’s T-50 prototype. Any similarities?

T-50 Factory 174
Factory 174’s T-50. Funnily enough, the solution to create an angled front plate instead of a stepped one would become a major event during IS-2 production. Of course the IS-2 inherited the stepped front plate from the KV-13.

Work on the KV-13 was stalled by Stalin, as he saw the need to focus on the KV-1 and KV-1S. And it wasn’t resumed until September, 1942. However Factory #100 still tinkered with the design and tested out some design elements in the meantime. Even then, Factory #100 was not allowed to work on the vehicle as they were to help out ChKZ with their start of T-34 production. This order was mostly ignored, and the first prototype was finished by the end of the month. This fact wasn’t welcomed by the higher ups, especially when its performance was less than hoped for.

KV-13 September 42
KV-13 prototype in its original configuration. September 1942.

To say the first prototype was flawed is almost an understatement. Its suspension fell apart from rough terrain. To steer it and use the clutch one needed to apply ones entire body weight. Its engine overheated and of course a host of other more common issues. Most of these issues were worked on and replaced and repaired until the end of 1942, but it was clear the design needed more than just quick fixes. Not only that, a three man turret was required all the way back in July, which had not made it to the prototype. Though it had been designed.

KV-13 3 man turret
KV-13 with three man turret designed in the summer of 1942.

Work on an improved KV-13 began in November '42, this vehicle will be described in another suggestion. But as for the fruits of the project in the end. Although the improved KV-13 project ended similarly to the first KV-13, it was ordered to be redesigned to fit an 85mm. Which is what became the IS-1.

KV-13 improved
The improved KV-13 on its first day, March 1943.



  • Commander
  • Loader
  • Driver


  • 76mm ZiS-5 (Ammo: 57-65* (See footnotes))
    Vertical traverse: -5°/+25°
    Telescopic: DT-7
    Parascopic: PT4-7
  • 7.62mm DT coaxial (Ammo: 945)


  • Weight (total): 31 000kg or 32 400kg* (See footnotes)
    Length (hull): 6650mm
  • Width (total): 2800mm
  • Height (total): 2000mm
  • Turret ring: 1420mm


  • Engine: V-2K (600hp)
  • Transmission:
    Forward gears: 9
    Reverse gears: 1
  • Top speed: 55km/h


See picture

KV-13 armor


  • Front:
    Upper: 120 at 13°
    Middle: 80mm at 70°
    Lower: 100mm at 40°
  • Sides:
    Upper: 85mm at 0°
    Lower: 75mm at 0°
  • Rear:
    Upper: 60mm at 55°
    Lower: 85mm at 15°
  • Roof:
    Front: 30mm
    Rear: 20mm
  • Floor:
    Front: 30mm
    Rear: 20mm


  • Front: 85mm at 0°
    Mantlet: 90mm at 0°
  • Sides: 85mm at 20°
  • Rear: 80mm at 30°
  • Roof: 20mm


See footnotes
  1. In its initial state it used tracks and sprockets from the T-34, with proprietary road wheels. These were later replaced with components from the KV-1. When creating a model of the vehicle either state can be used.

  2. It is unclear why all sources list 57-65 shells of ammunition. The most likely answer is that the ammo racks were redesigned during its testing to support more. This should be reflected depending on what version is modelled.

  3. The weight of the vehicle is described as being less than 32 tonnes by Yuri Pasholok. It is likely that the vehicle increased in weight when it was equipped with suspension parts from the KV-1 and went above 32 tonnes instead. Zaloga says the vehicle weighed 31 tonnes, but it is not very specific.

Other images:

See images

KV-13 front
Front view of the KV-13, with T-34 tracks.

KV-13 rear
Rear view of the KV-13.

KV-13 side
Side view of the KV-13.

KV-13 engine deck
KV-13 from an angle where the hull and turret roofs can be seen.


  1. https://dzen.ru/a/X_94ZP2nolPThdf2?sid=103043105549737345

  2. https://dzen.ru/a/YMsniyPEpkwndI32?sid=13799915534243473

  3. Tank Archives: Kirov Factory's Light Alternative

  4. Tank Archives: Less Armour, More Mobility

  5. Tank Archives: Unlucky KV

  6. https://dzen.ru/a/X226CzqjnkOqxz6d?sid=343455091904197401

  7. Tank Archives: KV-13, First Steps

  8. Tank Archives: Second to Last Step

  9. Tank Archives: KV-13 Trials

  10. S. Zaloga, J. Kinnear. (2001) KV-1 & 2 Heavy Tanks 1939-1945. Osprey Military New Vanguard.

  11. A. G. Solyankin, M. V. Pavlov, I. V. Pavlov, I. G. Zheltov (2005) Отечественные бронированные машины. XX век. 1941–1945. (Eng. Domestic Armored Vehicles. XX Century. 1941–1945). Exprint.


Both these tanks will make for great suggestions!

  • +1 for the vehicle in the tech tree at br 4.7.
1 Like

Suggestion passed to the developers for consideration.

1 Like