KV-1S

This page is about the Soviet heavy tank KV-1S. For other versions, see KV-1 (Family).

KV-1S

KV-2 (1939)

KV-1 (ZiS-5)

KV-1S

KV-2 (1939)

KV-1 (ZiS-5)

USSR

II Rank

Battle rating:

AB	RB	SB
4.0	4.0	4.0

Class:

Heavy tank

Research:14 000

Purchase:32 000

Show in game

Description

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.

General info

Survivability and armour

Armourfront / side / back

Hull75 / 60 / 60

Turret82 / 82 / 82

Crew5 people

Visibility96 %

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.

Armour type:

• 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	30 mm
Cupola	60 mm			30 mm

Notes:

• 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.

Mobility

Speedforward / back

AB48 / 19 km/h

RB and SB45 / 18 km/h

Number of gears8 forward

3 back

Weight42.5 t

Engine power

AB1 145 hp

RB and SB600 hp

Power-to-weight ratio

AB26.9 hp/t

RB and SB14.1 hp/t

Game Mode	Max Speed (km/h)		Weight (tons)	Engine power (horsepower)		Power-to-weight ratio (hp/ton)
	Forward	Reverse		Stock	Upgraded	Stock	Upgraded
Arcade	48	19	42.5	775	1,145	18.24	26.94
Realistic	45	18		531	600	12.49	14.12

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

Repair costBasic → Reference

AB1 129 → 1 396

RB1 184 → 1 464

SB1 551 → 1 918

Total cost of modifications13 840

20 250

Talisman cost860

Crew training9 200

Experts32 000

Aces270

Research Aces250 000

Reward for battleAB / RB / SB

60 / 90 / 100 %

130 / 130 / 130 %

Modifications

Mobility	Protection	Firepower
Tracks Research: 690 Cost: 1 000 90 Suspension Research: 620 Cost: 890 80 Brake System Research: 620 Cost: 890 80 Filters Research: 870 Cost: 1 300 115 Transmission Research: 1 500 Cost: 2 200 195 Engine Research: 1 500 Cost: 2 200 195	Improved Parts Research: 690 Cost: 1 000 90 Improved FPE Research: 620 Cost: 890 80 Crew Replenishment Research: 870 Cost: 1 300 115	Horizontal Drive Research: 690 Cost: 1 000 90 76mm_AP_1942_ammo_pack Research: 690 Cost: 1 000 90 Adjustment of Fire Research: 620 Cost: 890 80 76mm_AP_1941_ammo_pack Research: 620 Cost: 890 80 Elevation Mechanism Research: 870 Cost: 1 300 115 76mm_APCR_1943_ammo_pack Research: 870 Cost: 1 300 115 76mm_ussr_Smoke_ammo_pack Research: 1 500 Cost: 2 200 195

Armaments

Main armament

76 mm ZIS-5 cannon

Ammunition114 rounds

Reloadbasic crew → aces

9.0 → 6.9 s

Vertical guidance-5° / 25°

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)
Mode	Capacity	Vertical	Horizontal	Stabilizer	Stock	Upgraded	Full	Expert	Aced	Stock	Full	Expert	Aced
Arcade	114	-5°/+25°	±180°	N/A	9.7	13.4	16.3	18.0	19.2	8.97	7.94	7.31	6.90
Realistic					7.1	8.4	10.2	11.3	12.0

Ammunition

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.

Penetration statistics
Ammunition	Type of warhead	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-350P	APCR	125	119	92	68	50	36
BR-350SP	APBC	102	100	91	81	72	64
BR-350B (MD-8 fuze)	APHEBC	94	92	83	73	65	57
OF-350M	HE	10	10	10	10	10	10
Sh-354T	Shrapnel	37	35	29	25	20	17

Shell details
Ammunition	Type of warhead	Velocity (m/s)	Projectile Mass (kg)	Fuse delay (m)	Fuse sensitivity (mm)	Explosive Mass (TNT equivalent) (g)	Ricochet
							0%	50%	100%
BR-350A (MD-5 fuze)	APHEBC	662	6.3	1.2	14	150	48°	63°	71°
BR-350P	APCR	950	3.02	N/A	N/A	N/A	66°	70°	72°
BR-350SP	APBC	655	6.78	N/A	N/A	N/A	48°	63°	71°
BR-350B (MD-8 fuze)	APHEBC	655	6.3	0.9	14	98.56	48°	63°	71°
OF-350M	HE	680	6.2	0.05	0.1	621	79°	80°	81°
Sh-354T	Shrapnel	680	6.2	0.5	8	85	62°	69°	73°

Smoke shell characteristics
Ammunition	Velocity (m/s)	Projectile Mass (kg)	Screen radius (m)	Screen deploy time (s)	Screen hold time (s)	Explosive Mass (TNT equivalent) (g)
D-350A	680	6.45	13	5	20	50

Ammo racks

Ammo racks of the KV-1S

Full ammo	1st rack empty	2nd rack empty	3rd rack empty	4th rack empty	5th rack empty	6th rack empty	7th rack empty	Visual discrepancy
114	110 (+4)	105 (+9)	100 (+14)	68 (+46)	36 (+78)	24 (+90)	1 (+113)	No

Notes:

• 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.

Machine guns

7.62 mm DT machine gun (coaxial)

Ammunition3 087 rounds

Belt capacity63 rounds

Reloadbasic crew → aces

10.4 → 8.0 s

Fire rate600 shots/min

7.62 mm DT
Mount	Capacity (Belt)	Fire rate	Vertical	Horizontal
Coaxial	3,087 (63)	600	N/A	N/A

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

Pros:

• Faster than its predecessor and successor, meaning more flexible tactics
• High reverse speed and acceleration, allowing it to get back into cover quickly after firing
• Adequate gun with nice penetration and great damage against common foes like Pz.IV G, Cromwell
• Bouncy turret front
• Wide tracks make for good cross-country performance
• Resilient. Can remain reasonably effective, even with a lot of damage

Cons:

• Weakened armour is considerably more vulnerable especially against tanks with long barreled guns eg. StuG III and Pz.IV H
• Cramped turret puts all crew at risk of being taken out in one shot
• Still a heavy vehicle with poor acceleration. Cannot keep up with medium tanks like T-34
• Gun lacks penetration against heavier opponents: The Churchills are very hard to get through. APCR is unreliable.
• -5° gun depression is not enough for hilly battlefields
• Turret rotation is slow, unable to respond to flankers quickly

History

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.

Development

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.

Design

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.

Media

Skins

• Skins and camouflages for the KV-1S from live.warthunder.com.

Videos

The Shooting Range #49 - Pages of History section at 03:09 discusses the KV-1S.

See also

Other vehicles of similar configuration and role

• MK-II "Matilda" (USSR)
• Churchill Mk III
• ARL-44 (ACL-1)

External links

• [Devblog] KV-1S: How's the tank?
• [Wikipedia] Kliment Voroshilov tank
• [Tanks Encyclopedia] KV-1