|This page is about the Soviet heavy tank KV-1S. For other versions, see KV-1 (Family).|
The KV-1S is a rank II Soviet heavy tank with a battle rating of 4.0 (AB/RB/SB). It was introduced in Update 1.57 "Battle March". A lightened KV-1 made to improve its manoeuvrability, the KV-1S has less overall armour than the original design but keeps its same lethality with improved speed.
Compared to the KV-1 L-11, side and rear armour are decreased to 60 mm, lightening the vehicle and increasing its speed to maximum 43 kph. A new turret was installed, presenting a smaller profile, thicker armour, and better angling all around. The armament is also changed to the ZIS-5, the equivalent of its successor and the T-34's F-34 guns.
Survivability and armour
The KV-1S is a lighter, more mobile version of the KV-1, meaning it has thinner armour. The KV-1S features thinner hull side armour at 60 mm, thinner lower front plate at 60 mm, and a very weak gun mantlet of only ~50 mm thick. Though against opponents of lower BR the KV-1S can still utilise the angling tactic and stack the effective thickness up to 100 mm, the gun mantlet becomes a very fatal weak spot if the opponent knows it. At 50 mm unangled, even a Pz.III can frontally penetrate it and break the gun breech or knock out a few crews. But apart from the gun mantlet, the turret is overall more sturdy than the original KV-1, at 82 mm all-round. This may bounce off some poorly aimed shells if they impact the edge. Roof armour, at 30-40mm, is very reliable against strafing planes. Post-penetration survivability against common opponents is not great as the crew members are closely packed together. Overall, due to the reduction of armour thickness here and there, the KV-1S no longer grants the player a sturdy protection. Rather they must rely more on the improved mobility to not get hit.
- Rolled homogeneous armour (Hull, Turret roof)
- Cast homogeneous armour (Turret)
|Armour||Front (Slope angle)||Sides||Rear||Roof|
|Hull|| 75 mm (30°) Front plate
50 mm (70°) Front glacis
25 + 50-60 mm (25-70°) Joint plate
60 mm (26-50°) Lower glacis
|60 mm|| 60 mm (35-75°) Top
60 mm (2-69°) Bottom
| 40 mm Front |
30 mm Rear
|Turret|| 82 mm (2-76°) Turret front
50-75 mm (4-71°) Gun mantlet shield
90 mm (0-29°) Gun mantlet
|82 mm (0-25°)|| 82 mm (27-56°)
75 mm (1-43°) Machine gun port
|Cupola||60 mm||30 mm|
- Suspension wheels are 20 mm thick, tracks are 30 mm thick.
- The gun mantlet shield has varying thickness, thickest just a little above and below the centre 55 mm area.
|Game Mode||Max Speed (km/h)||Weight (tons)||Engine power (horsepower)||Power-to-weight ratio (hp/ton)|
The core of the KV-1S is its enhanced mobility over the heavier KV-1. With a powerful 600 hp engine driving a 42-ton chassis, the KV-1S is quite fast and mobile, and may even resemble the handling of a T-34 sometimes, though the acceleration is of course slower. The top speed of 45 km/h seems average, but due to the increased power-to-weight ratio the KV-1S can reach an average speed of ~35 km/h on most surfaces which is faster than common heavy tanks. It also performs significantly better on soft terrain and hills, when other heavy tanks tend to struggle to move around the KV-1S can pretty much keep up with medium tanks. The KV series tank has an impressive reverse speed topping at 17 km/h, allowing it to quickly reverse away from danger. The hull traverse speed is also good so the player can angle very fast should a flanker appears unexpectedly. Overall the KV-1S can be treated and played as a heavily armoured medium tank.
Modifications and economy
The KV-1S is armed with a 76 mm ZIS-5 cannon which is quite similar to that of a SU-76M. In general, the gun has inadequate penetration at this BR but comes with a wide range of ammunition. From APHE to APCR and smoke shells, these shells can fit various scenarios. The 76 mm APHE shells have an explosive filler, allowing them to knock out most enemy tanks with a single shot if it is placed correctly. However, their mediocre penetration of ~90 mm becomes below average when facing well-armoured tanks at similar BR like the Pz.IV H, StuG III G and T14, especially when at a distance or when they are angling. The player have to be familiar with common foes' weak spots or else they will struggle to penetrate in most cases.
The gun depression is of a typical Soviet style, at -5 degrees, which is inadequate for mountainous battlefields. The aiming speed can be underwhelming against fast flankers, but overall the turret rotation speed of ~10 degree/s is enough for combat. Lastly, the gunsight magnification is poor at 3.5x. But given the curved trajectory and low projectile velocity of the ZIS-5 cannon, long range battle is not a good role for the KV-1S anyways, thus this level of zoom is generally enough.
|76 mm ZIS-5||Turret rotation speed (°/s)||Reloading rate (seconds)|
The available ammunition allows for engaging all types of targets:
- BR-350A (MD-5 fuze): APHEBC; a shell with high explosive mass that will one-shot any tank it penetrates but has an average penetration power.
- BR-350P: APCR; a composite round with the best penetration but no explosive filler and will only penetrate flat vertical surfaces.
- BR-350SP: APBC; a solid shot with an even better penetration but no explosive filler.
- BR-350B (MD-8 fuze): APHEBC; same shell as the BR-350A but with increased penetration at the cost of slightly less explosive filler.
- OF-350M: HE; useful for destroying open and lightly armoured vehicles.
- Sh-354T: Shrapnel; useful against vehicles that are resistant to the HE shells but too thinly armoured to trigger the fuzes of AP shells.
- D-350A: Smoke; useful to blind enemy vehicles that are too remote for you to disable so that you can progress towards objectives.
|Ammunition|| Type of
|Penetration @ 0° Angle of Attack (mm)|
|10 m||100 m||500 m||1,000 m||1,500 m||2,000 m|
|BR-350A (MD-5 fuze)||APHEBC||87||85||76||67||59||52|
|BR-350B (MD-8 fuze)||APHEBC||94||92||83||73||65||57|
|Ammunition|| Type of
| Fuse delay
| Fuse sensitivity
| Explosive Mass
(TNT equivalent) (g)
|BR-350A (MD-5 fuze)||APHEBC||662||6.3||1.2||14||150||48°||63°||71°|
|BR-350B (MD-8 fuze)||APHEBC||655||6.3||0.9||14||98.56||48°||63°||71°|
|Smoke shell characteristics|
| Screen radius
| Screen deploy time
| Screen hold time
| Explosive Mass|
(TNT equivalent) (g)
|114||110 (+4)||105 (+9)||100 (+14)||68 (+46)||36 (+78)||24 (+90)||1 (+113)||No|
- As they are modeled by sets of 2, shells disappear from the rack only after you fire both shells in the set.
- Turret empty: 100 (+14) shells.
|7.62 mm DT|
|Mount||Capacity (Belt)||Fire rate||Vertical||Horizontal|
The small calibre of the DT machine gun makes it largely ineffective against all armoured vehicles but the ones with an open compartment. It still can be used to ping targets as a rangefinding help or to mow down minor obstacles blocking your line of sight.
Usage in battles
When playing the KV-1S, remember that you are still a heavy tank. Keep your front armour facing your enemies at all times, and preferably angled (but slightly less than KV-1 (L-11)). The turret is more durable and can deflect more shots than before, so if possible expose your turret only. Gun has no special penetration value, so try to target weak spots or areas with the least armour. Flanking attacks could end in a fiery demise. Also, this tank is still a KV-1 in its heart.
The best tactics for this tank is: keep a low profile and stay behind the main assault. When your team has advanced to the enemy's base, the KV-1s is best used to round up straggling enemy tanks behind your lines. If these tanks aren't destroyed, they'll attack your team's rear.
The common enemies are armed with guns that usually can penetrate the driver's hatch. Watch out for enemy T-34 (especially mod. 1941 and 1942, sometimes mods 1943 and the 57 variants), since they can flank you easily. Also, watch out for all German Pz.IV & StuG armed with long 7.5 cm gun, as it can penetrate your front armour even if you are angled.
This vehicle (due to its higher BR) can also meet many opponents that your armour has no chance of stopping, avoid direct confrontation with them. (Includes: T-34-85, SU-85, Dicker Max & Nashorn, Sherman Firefly & Achilles)
Meeting other KV-1's and Churchill may become a stalemate as the KV-1S gun may not penetrate against their formidable armour. This leads to the hope that the APCR ammunition works, and the firing of several rounds into the target for penetration.
Pros and cons
- Faster than its predecessor and successor, yet frontal armour is the same
- High reverse speed and acceleration, allowing it to get back into cover quickly after firing
- Very hard to knock out in one shot
- Adequate gun
- Bouncy turret front
- Wide tracks make for good cross-country performance
- Resilient. Can remain reasonably effective, even with a lot of damage
- Very effective overall
- Side armour is considerably weaker (75 mm into 60 mm)
- Turret is cramped
- Vulnerable to the long-barreled 75 mm gun of the StuG III and Pz.IV F2,G, H and J
- Still carries most of the flaws of the KV-1 L-11
- Still a heavy vehicle, poor acceleration.
- Still cannot move on pace with T-34s
- Gun lacks penetration against heavier opponents: The KV-1 ZiS-5 and both Churchills are very hard to get through. APCR is unreliable.
The KV-1S was an attempt by the Soviet Union (USSR) to come up with a more mobile variant of the KV-1 heavy tank. The 'S' stood for 'Skorostnoy' which means 'fast' in English.
After the Soviet Union met Germany on the field of battle in 1941, both nations began attempts to up-armour their tanks. The Soviet efforts resulted in the KV-1 Model 1942 which thickened the armour but did not improve the engine. Soviet tank crews were pleased with the increased protection but did not appreciate the worsened mobility from increased weight. As such, a project began to design a KV-1 with greater mobility. The resulting tank was designated as the KV-1S.
Measures taken to increase the mobility included reduction of weight by decreasing armour thickness as well as by fitting a more powerful engine.
The KV-1S had a crew of five, two in the hull and three in the turret. It weighed only 42.5 tonnes compared to 47 tonnes on a KV-1B Model 1942. The KV-1S turret was a completely new, cast (rounded shape) turret that also featured a new commander's cupola with greater field of view. The armament consisted of a 76.2 mm ZiS-5 tank gun as well as three 7.62 mm DT machine guns; one coaxial to the main gun, one in the rear of the turret, and in a ball mount in the hull front.
The powerplant used was a 600 brake horsepower V2 engine. The road wheels were made smaller and a new planetary transmission gearbox was fitted. This allowed a top speed of 40 kilometers per hour compared to 28 kph on the KV-1B Model 1942. The armour though was reduced from 20 - 130 mm to only 20 - 82 mm on the KV-1S.
Production and Service
Production lasted from August 1942 until late 1943 with a total of 1,370 KV-1S tanks built. The production ended when it did due to thoughts that it was a useless vehicle due to the T-34-76 being able to do everything the KV-1S could. The mobility of the KV-1S met requirements but only with a reduction in armour, which made the mobility a moot point especially since it was also more expensive than a T-34-76.
The KV-1S did end up serving on the front line for a while, taking part in the Battle of Kursk in 1943 under the herd Guards Heavy Tank Brigade. It's stated by some sources that the KV-1S had also taken part in the Berlin offensive but that may not be true because by then the KV-1S had been mostly removed from combat units.
- Other vehicles of similar configuration and role
|USSR heavy tanks|
|KV-1||KV-1 (L-11) · KV-1 (ZiS-5) · KV-1E · KV-1S|
|KV-2||KV-2 (1939) · KV-2 (1940) · KV-2 (ZiS-6) · KV-220|
|Other KVs||KV-85 · KV-122|
|IS-1/2||IS-1 · IS-2 · IS-2 (1944) · IS-2 "Revenge"|
|Other IS tanks||IS-3 · IS-4M · IS-6 · IS-7|
|T-10||T-10A · T-10M|
|Multi-turreted||T-35 · SMK|