IS-4M

IS-4M

IS-3

T-10M

IS-4M

IS-3

T-10M

USSR

V Rank

Battle rating:

AB	RB	SB
7.7	7.7	7.7

Class:

Heavy tank

Research:120 000

Purchase:340 000

Description

The IS-4M is an improved modification of the fourth variant of the IS heavy tank family. Like the IS-3, the IS-4 (designation Object 701) was intended to replace the IS-2. The IS-4 was designed to be the pride of the Soviet Army, with extremely thick armour, a weight of 53 tonnes, and a 750 horsepower V-12 diesel engine capable of reaching speeds of up to 43 km/h. Despite being an upgrade to the IS-2, it never offered much to the table, particularly when compared to the IS-3, a lighter, faster, and cheaper tank that had stunned the Western world only a few years previously. The IS-4, most importantly, used the same 122 mm D-25T tank gun as the IS-2 and IS-3. Production began in March 1947 and stopped in 1949, as any work on tanks weighing more than 50 tonnes was to be terminated. The tank proved to be too heavy, sluggish, and poorly built. IS-4M, a small batch of 25 units with some enhancements, was constructed in 1951. Only 258 units were built in total.

Introduced in the Closed Beta Test for Ground Forces before Update 1.41, the IS-4M is an immediate successor of the IS-3, and it has even greater armour, making it difficult for many opponents to penetrate from the front. Needless to say, this tank is nearly invulnerable to conventional ammunition from the front. Unfortunately, the main armament remains the same 122 mm D-25T tank gun used on all prior IS heavy tank variants beginning with the IS-2, and at this rank, it simply feels inadequate sometimes. The gameplay differs slightly from its predecessor in that angling can work, but it must be done properly. A small angle will enhance the hull armour all around from the frontal perspective. Furthermore, since it is substantially heavier, the IS-4M is less manoeuvrable, making it difficult to play in faster-paced battles in higher ranks.

General info

Survivability and armour

Smoke grenades

Creation of a smoke screen in front of the vehicle

Armourfront / side / back

Hull160 / 160 / 100

Turret250 / 200 / 170

Crew4 people

Visibility87 %

The IS-4M has very good armour although a very cramped crew compartment. Most shots will not be able to penetrate its frontal armour, and the turret is also very tricky to penetrate from the sides. However the crammed crew is very vulnerable to any shot that manages to penetrate, and in those situations surviving a hit is very unlikely.

Armour type:

• Rolled homogeneous armour (Hull, Turret roof, Hatch roof)
• Cast homogeneous armour (Turret)

Armour	Front	Sides	Rear	Roof
Hull	140 mm (62°) Front glacis 160 mm (40°) Lower glacis 160 mm (34-77°) Driver's port 40 mm (44-87°) Top of Driver's port	160 mm (30-53°) Top 160 mm Middle 30 mm (61°) Bottom	100 mm (37°) Top 30 mm (80°) Middle 100 mm (31-39°) Bottom	30 mm
Turret	200-250 mm (2-89°) Turret front 200 mm (0-65°) , 170 + 250 mm (2-61°) Gun mantlet	200 mm (3-40°)	150 (62-72°) Top 170 mm (21-49°) Bottom	30 mm Front, Hatch roof, Ventilators 50 mm Front sides 170 mm Center

Notes:

• Suspension wheels are 20 mm thick, torsion bars are 10 mm thick, and tracks are 30 mm thick.
• Very angled turret, prone to bounce shots

Mobility

Speedforward / back

AB46 / 12 km/h

RB and SB43 / 11 km/h

Number of gears6 forward

3 back

Weight60.0 t

Engine power

AB1 431 hp

RB and SB750 hp

Power-to-weight ratio

AB23.9 hp/t

RB and SB12.5 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	46	12	60	968	1,431	16.13	23.85
Realistic	43	11		663	750	11.05	12.5

The increased weight of the IS-4M compared to the IS-3 means a decrease in overall mobility. Its top speed is quite mediocre and the tank suffers in harsh terrain; while the reverse speed is good, its acceleration is not the best. Overall, it's not very mobile, even for a heavy tank.

Modifications and economy

Repair costBasic → Reference

AB5 577 → 7 238

RB5 906 → 7 665

SB9 398 → 12 198

Total cost of modifications98 000

164 000

Talisman cost2 200

Crew training98 000

Experts340 000

Aces1 300

Research Aces780 000

Reward for battleAB / RB / SB

150 / 210 / 250 %

202 / 202 / 202 %

Modifications

Mobility	Protection	Firepower
Tracks Research: 6 800 Cost: 11 000 240 Suspension Research: 4 600 Cost: 7 400 165 Brake System Research: 4 600 Cost: 7 400 165 Filters Research: 6 400 Cost: 10 000 230 Transmission Research: 11 000 Cost: 18 000 390 Engine Research: 11 000 Cost: 18 000 390	Improved Parts Research: 4 400 Cost: 11 000 240 Improved FPE Research: 3 000 Cost: 7 400 165 Crew Replenishment Research: 6 400 Cost: 10 000 230	Horizontal Drive Research: 6 800 Cost: 11 000 240 Adjustment of Fire Research: 4 600 Cost: 7 400 165 122mm_APHE_ammo_pack Research: 4 600 Cost: 7 400 165 Elevation Mechanism Research: 6 400 Cost: 10 000 230 122mm_APCBC_ammo_pack Research: 6 400 Cost: 10 000 230 Smoke grenade Research: 11 000 Cost: 18 000 390

Armaments

Main armament

122 mm D-25T cannon

Ammunition30 rounds

Reloadbasic crew → aces

27.1 → 20.8 s

Vertical guidance-3° / 19°

The IS-4M retains the the same 122 mm D-25T cannon found in the IS-2. It's a very capable cannon, with a good damage output and good penetration values for its BR-471D shell. However this means that its reload rate is very low, with 27 seconds when stock and 20.8 seconds with an Aced crew. That means that, even in a best case scenario, it's not capable of firing more than 3 shots per minute.

122 mm D-25T					Turret rotation speed (°/s)					Reloading rate (seconds)
Mode	Capacity	Vertical	Horizontal	Stabilizer	Stock	Upgraded	Full	Expert	Aced	Stock	Full	Expert	Aced
Arcade	30	-3°/+19°	±180°	N/A	8.1	11.2	13.6	15.0	16.0	27.04	23.92	22.05	20.80
Realistic					6.0	7.0	8.5	9.4	10.0

Ammunition

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-471	APHE	205	201	182	161	143	127
BR-471B	APHEBC	205	203	192	178	166	155
BR-471D	APCBC	230	227	215	200	186	173
OF-471	HE	37	37	37	37	37	37

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-471	APHE	795	25	1.2	19	246.4	47°	60°	65°
BR-471B	APHEBC	795	25	1.2	19	246.4	48°	63°	71°
BR-471D	APCBC	800	25	1.2	19	192.5	48°	63°	71°
OF-471	HE	795	25	0	0.1	3,600	79°	80°	81°

Ammo racks

Ammo racks of the IS-4M

Full ammo	Ammo part	1st rack empty	2nd rack empty	3rd rack empty	4th rack empty	5th rack empty	6th rack empty	Visual discrepancy
30	Projectiles Propellants	29 (+1) 29 (+1)	24 (+6) 24 (+6)	19 (+11) 19 (+11)	14 (+16) 14 (+16)	9 (+21) 9 (+21)	1 (+29) 1 (+29)	No

Machine guns

12.7 mm DShK machine gun (coaxial)

Ammunition1 000 rounds

Belt capacity50 rounds

Reloadbasic crew → aces

10.4 → 8.0 s

Fire rate600 shots/min

12.7 mm DShK machine gun

Ammunition250 rounds

Belt capacity50 rounds

Reloadbasic crew → aces

10.4 → 8.0 s

Fire rate600 shots/min

Vertical guidance-10° / 60°

12.7 mm DShK
Mount	Capacity (Belt)	Fire rate	Vertical	Horizontal
Coaxial	1,000 (50)	600	N/A	N/A
Pintle	250 (50)	600	-10°/+60°	±180°

Usage in battles

The IS-4M is a direct successor to the IS-3, and it features even more armour, so much armour that some APDS and APFSDS cannot penetrate its UFP and most of the turret, needless to say this tank is practically invulnerable to conventional rounds from the front. Unfortunately the gun remains the same 122 mm D-25T that is featured on all IS-series tanks from the IS-2, and at its BR it isn't enough sometimes, while other times a weird bounce can still lead to some good hits. Overall, though, this tank feels much better at its BR than the IS-3, which has a huge shot trap.

General Gameplay

The playstyle is slightly different from its predecessor, as angling can work - it just needs to be done carefully. The frontal side armour is actually thicker than the front, so a slight angle will even-out hull armour all around (in a best case scenario it can get to 275 mm, or just slightly more). Also, the IS-4M is less mobile, because it's heavier - all speeds are dampened and mobility is heavily impaired. However, if you've played the stock IS-3 this tank will feel a bit better.

Arcade Battles

The IS-4M will show a lot of red and yellow on the reticle when a player looks at it in Arcade. Only some HEAT and APFSDS shells can penetrate this beast frontally, and damage will only be substantial if the player takes their time to aim at the important components, because some shells will penetrate but their effect will be minimal inside the tank. However, there is little the IS-4M can do to make it harder to be damaged, because there are practically no weakspots to hide, and wiggling will not stop top rounds from penetrating.

In Arcade Battles, the improved speed should be used to rush any lone enemies and objectives. When this tank is at speed, enemies will often shoot the biggest part they see - the UFP, and many shots will bounce or not penetrate if they hit at an awkward angle; but even if they do penetrate the UFP, the IS-4M will be able to return fire because only the driver and possibly the transmission are knocked out. Very rarely will the IS-4M get one-shot through the UFP. Again, being at speed is being protected, and it is a big surprise to many enemies when a heavy tank drives around a corner at high speed - giving you extra seconds to take aim and disable them (usually you will pass them, so their side and/or rear is visible).

Rushing mostly works in cities, where your speed is further increased by paved roads, and enemies will be spaced apart between buildings. In open areas, rushing will usually end up in the IS-4's demise, as opponents will quickly flank you because it's easy to do.

If rushing is not an option, and you find yourself in close-quarters, your best bet is to try to bait shots either for yourself or for your teammates. You can poke your gun barrel out from a corner, and if enemies shoot it, your teammates can drive out and destroy the enemy. Poking out the side of the turret or heavily angled UFP is an option, but most enemies will realize that it's no use shooting there.

Realistic Battles

In Realistic, the IS-4M retains its ability to rush, although it's subdued. When fully upgraded you can still get up to speed and surprise enemies, especially if you can choose weird routes that are not likely to be checked by enemies. From experience, it's possible to destroy up to 3-4 enemy tanks on city maps like Alaska, American Desert and Middle East, when playing against a good mix of lighter tanks (e.g. Leopard I, Centurion Mk 10, Vickers MBT), as well as some heavier vehicles that can be out-manoeuvred.

Armour can protect the IS-4M, but most enemies usually have HEAT loaded, or will be able to load it for the next shot. Most importantly you should never find yourself fighting alone against 3 or more enemies, even 2 are hard to handle most of the time. At least when fighting one-on-one you can always try to retreat or one-shot them, depending on the situation (i.e. either gunner/gun or driver/transmission knocked out).

All in all, you should play the IS-4M as if it is a slow medium tank with sub-par firepower due to the reload speed - hope that armour withstands some shots, while taking on enemies one or two at a time; if speed can be gained - use it.

The Stock Grind

The IS-4M is less painful to play when stock because at times you can get very lucky matches where no-one seems to penetrate you and you get tons of research points for withstanding a lot of shots. Nonetheless, the experience is very much similar to the IS-3 - slow tank, slow reload, gun and engine are often out of commission. Due to this, you must research Parts and FPE first, this is extremely important. Generally, you would want to be behind your teammates, to let them direct shots away from you, when reloaded you can poke out and shoot your shot, right before going back into the cover or behind teammates. Sniping is an option, but it's not the most viable since there's quite a lot of bullet drop and missing your shots will cause the very long reload.

Pros and cons

Pros:

• Very good frontal armour; can bounce 128 mm shells from the Maus and even point blank shots from some British tanks using APDS (like Vickers MBT) will often be deflected, unless hit in a weak spot
• Armour on the back of the turret is very tough and due to its angle is arguably as strong as the front, causing confusion and/or shock for enemies expecting the rear to be weaker
• Retains the powerful 122 mm gun and ammunition of the previous IS-3
• Strong combination of armour and armament
• Good reverse speed for a heavy tank
• Can easily knock out most tanks with a single shot

Cons:

• Priority target for the enemy team due to its fearsome reputation
• Long reload of 25 seconds
• Frontal armour has a small but noticeable weak spot below the gun barrel, where the turret meets the hull, and shots coming through it often one-shot IS-4M
• Ammo rack in the back of the turret; if a shell penetrates, the ammo could detonate
• Can be vulnerable to tanks equipped with HEAT, APDS and APFSDS
• Armour penetration for the shells can be lacking at the rank
• Packed crew can be knocked out easily in a single shot
• Very little gun depression

History

Development

During the development of the IS-3 in 1944 under General Nikolai Dukhov, a separate project was underway by a design team led by L.S. Troyanov to improve the IS-2 design. This separate project commenced under the designation Object 701. The project produced three proposed design. The Object 701-2 with a S-34 100 mm gun, 701-5 with a different armour configuration, and the 701-6 with the 122 mm D-25 gun. The 701-6 was accepted for further development, to which was modified with thicker armour, longer hull, and a more powerful engine. There was some implementation of German designs into the prototype; the engine has a cooling system that uses a pair of circular fans on the engine deck, a feature also is seen on the Panther tank.

Usage

Object 701 was eventually approved for production in 1947 as the IS-4. The production turned out 200 tanks (some sources say 250) before the production was halted. The reason being that the IS-4 was criticized for being inadequate in mobility despite its new engine. While production ended, the remaining IS-4 still saw service in the Soviet Union. When the Korean War broke out in 1950 and the United States and its allies got involved, the IS-4s were all shipped to the Far East of the Soviet Union in anticipation of Soviet intervention in the Korean War. They were not committed despite pressure by the Chinese from fear of inciting another world war. Even so, the IS-4 stayed in the region ready for action. In the late 1950s, the IS-4 underwent a modernization program along the lines of the IS-3 with increased ammo stowage, new machine gun armaments, new gun optics, better engine, and better filtration system and this modernized variant was named the IS-4M. The IS-4 stayed in service in the Soviet Union until the 1960s.

Legacy

The IS-4, as a relatively unsuccessful Soviet tank, faded to obscurity with little information on it past its development period. It was the heaviest of the Soviet heavy tanks that were slated for production. The IS-4's design was further developed on in the IS tank family with the Object 703, with the design using an electrical transmission instead of a mechanical one. This vehicle redesignated the IS-6, also proved to be problematic and was shelved.

Archive of the in-game description

Development of this tank began in July 1943 at the ChKZ factory. The main impetus for creating a new Soviet heavy tank was the prospect of being able to install more powerful artillery on it than what was installed on the IS-2. The vehicle underwent testing until the autumn of 1944. The new vehicle had one inarguable virtue - no tank or anti-tank cannon of Soviet or German make could penetrate its 160 mm frontal armour. At the end of 1944, two more vehicles equipped with modernised transmission were produced. In April 1945, the tank was put into service and mass-produced under the designation IS-4. The vehicle's hull was fully welded, while its turret was cast with tapering armour thickness. Along with its 122 mm D-25T cannon, it was also armed with a coaxial 12.7 mm machine gun. An identical machine gun was placed as an anti-aircraft gun on a ring mount above the loader's hatch. One of the vehicle's characteristic features was its original ammunition rack, in which shells were housed in special metal canisters. The tank had epicyclic transmission and individual torsion-bar suspension. The crew consisted of 4 people. The vehicle's powertrain was a 750 hp B-12 diesel engine. With this engine, the tank could reach 43 km/h on-road. The IS-4 was mass-produced until 1949. In total, around 250 of them were made. These vehicles served in the Far East. It became clear during its deployment that the tank's mass exceeded the carrying capacity of most bridges and transport platforms. It was this fact that effectively buried the idea of building vehicles with a mass greater than 50 tonnes. The IS-4 was taken out of operation and placed in long-term storage, and then withdrawn from service entirely. After this, it was often used on ballistic ranges as a target.

Media

Skins

• Skins and camouflages for the IS-4M from live.warthunder.com.

Videos

Top 7 most armoured vehicles discusses the IS-4M at 3:49 - War Thunder Official Channel

The Shooting Range #95 - Pages of History section at 07:03 discusses the IS-4M.

See also

Other vehicles of similar configuration and role

• M103
• Conqueror

External links

References

Chelyabinsk Tractor Plant (Челябинский тракторный завод)
IFVs
BMP-1	BMP-1
Heavy Tanks
KV	KV-85 · KV-122
IS-1/2	IS-1 · IS-2 · IS-2 (1944) · IS-2 "Revenge" · IS-2 No.321
T-10	T-10A · T-10M
Other IS Tanks	IS-3 · IS-4M
Tank Destroyers
KV Derivatives	SU-152
IS Derivatives	ISU-152 · ISU-122 · ISU-122S · Object 268
Export
IS-2	␗IS-2 · IS-2 No.402 · ␗IS-2 (1944)
ISU	␗ISU-152 · ␗ISU-122
IFVs	SPz BMP-1
See Also	Leningrad Kirov Plant