IS-3M (Model 1960)

Savage_Virus_R6 · August 11, 2026, 11:28am

Would you like to see IS-3M in-game?

Yes, as a Tech-Tree Vehicle
Yes, as a Premium Vehicle
Yes, as a Squadron Vehicle
Yes, as an Event Vehicle
Yes, rework the current model and rename it to “IS-3M” (or make it a researchable upgrade option for the current IS-3)
No, I do not want to see IS-3M in-game.

0 voters

Introduction

The IS-3M represents the final and most refined version of one of the most recognizable Soviet heavy tanks ever built. The original IS-3, with its “pike nose” hull, low rounded turret, and powerful 122 mm gun, appeared at the very end of the Second World War, but arrived too late to see combat. Its real service life belonged to the Cold War. To keep the vehicle useful, surviving IS-3 tanks were gradually repaired, improved, and eventually modernized into the IS-3M. This upgrade corrected many of the tank’s worst flaws and brought it closer to post-war Soviet standards. The IS-3M received a 520 hp V-54K-IS engine, improved communications equipment, night-driving equipment, rear fuel drum mounts for additional range, DShKM and DTM machine guns, and several smaller reliability-focused upgrades. While it was still fundamentally the same heavy tank, the IS-3M was a more practical and serviceable Cold War version of the original IS-3.

IMPORTANT: It is not the same IS-3 currently represented in War Thunder. For reasons unknown to me, the War Thunder version appears to be an intermediate configuration between the original IS-3 and the fully modernized IS-3M. This suggestion, however, represents the final modernized version of the tank, which remained in service long enough to serve with the Armed Forces of the Russian Federation until the late 1990s.

IS-3M vs IS-3 (In-game model):

V-54K-IS 520 hp engine instead of the 460 hp
DShKM heavy machine gun instead of the original DShK
DTM coaxial machine gun instead of the original DT
Two front FG-100 infrared/blackout projectors covered by cages for the driver’s night-vision equipment instead of a single basic projector and a horn
Box/canister of unknown purpose mounted on top of the front right mudguard (and sometime another box of unknown purpose (likely fuel pump) was mounted on top of the left mudguard)
Rear mounts for two 200-litre fuel drums (could be mounted with the smoke charges equipped)
Rear-mounted BDSh-5 smoke charges (below the 200-litre fuel drums) retained

In my opinion, the IS-3M should not be added as a separate vehicle. Instead, the current in-game model could be reworked and renamed as the IS-3M, similar to the situation we have with the IS-4M. The original base IS-3 could then be introduced as a premium vehicle, in much the same way as the T-10A was added. Alternatively, the IS-3M could be added as a researchable modernization for the IS-3 already present in the game, allowing the current vehicle to be upgraded into its final late-service configuration. I also think the IS-3M should receive its full external fuel stowage, including all six fuel canisters, while retaining the rear smoke canisters. This would be realistic for a late-service IS-3M and would give the tank a proper Cold War appearance. It would also help visually separate it from the base IS-3, instead of making it feel like only a slightly altered version of the same vehicle.

History of the IS-3(M)

Spoiler

The IS-3 was developed during the final stage of the Second World War as the next step after the IS-2. Soviet designers wanted a heavy tank with stronger frontal protection and a lower, more compact silhouette. The result was a vehicle with a sharply angled “pike nose” hull and a rounded cast turret, both of which gave the tank a very distinctive appearance. The main armament remained the 122 mm D-25T gun. This meant that the IS-3 did not offer a major increase in firepower over the late IS-2, but its armor layout was far more advanced. The new hull shape was intended to improve frontal protection, while the low turret made the vehicle harder to hit and gave it a very modern profile for 1945. The first IS-3 tanks appeared too late to take part in combat during the Second World War. They also did not participate in the Soviet campaign against Japan. Their first major public appearance came on 7 September 1945, when 52 IS-3 tanks from the 71st Guards Heavy Tank Regiment took part in the Allied Victory Parade in Berlin. The tank’s appearance had a strong psychological effect, as it gave the impression that the USSR had already moved beyond the wartime generation of heavy tanks.

The Original IS-3 vs IS-2M

Spoiler

One way to tell the different IS-3 versions apart is by looking at the side hatches. The earliest vehicles had none, while 1946 production tanks had three per side. The IS-3M later had four per side, and for some reason unknown to me, the current in-game IS-3 also has the four-hatch layout. The original vehicles also did not have the side skirts seen on the IS-3M and on the current in-game version. However, the biggest visual giveaways to differentiate the originals vs the M are the traffic lights.

Model 1945

Model 1946

On the drawing above, you can see the differences between the original IS-3 and the IS-3M. Interestingly, the IS-3M also has a box mounted above the left mudguard. I suspect this may be the fuel-pump box seen on other Soviet Cold War tanks, although I am not certain.

The photo above shows a Model 1945 IS-3 during the Berlin Victory Parade. Notice that it has no side skirts, but it does retain the convoy light and horn arrangement also seen on the in-game version.

Production continued after the war, with the IS-3 being built from 1945 to 1946. Around 2,300 vehicles were produced. The tank entered service with Soviet heavy tank and heavy tank-self-propelled regiments, but it soon became clear that the design had serious problems. The IS-3 had been developed very quickly, and many parts of the vehicle had not been properly refined before production began. The most serious issues were connected with reliability and structural strength. The tank suffered from engine and transmission problems, as well as weaknesses in the hull structure. The famous pike-nose hull offered excellent frontal shaping on paper, but the vehicle as a whole required major correction work to make it reliable enough for long-term service. Because of these problems, the IS-3 went through repair and improvement work after the war. One of the key early programs was the UKN program, which stood for “elimination of design defects.” This work corrected many of the vehicle’s reliability and structural issues and eventually culminated in the IS-3M.

Alongside other Second World War-era vehicles brought up to Cold War standards, the IS-3M represented the modernization program for the IS-3 heavy tank. The tank received the more reliable and widely available 520 hp V-54 engine developed for the T-54, also used in other Soviet post-war modernizations such as the ISU-152K/M, IS-2M, T-44M, and even some upgraded T-34-85s. Its communications equipment was brought closer to T-54/T-55 standards, while additional fuel stowage improved operational range. The tank also received night-driving equipment, allowing it to move at night, although not necessarily fight effectively in darkness. Together with several other smaller upgrades, these changes made the IS-3M a more practical and serviceable Cold War version of the original IS-3.

The IS-3 did see combat during the Cold War. Soviet IS-3s were used during the suppression of the Hungarian uprising in 1956. Outside the USSR, the tank was exported in limited numbers to several countries. Egypt became one of the most important foreign users. In Sinai, the tank’s armor proved to be highly impressive, but it suffered from poor mobility and reliability issues (due to heat). These problems were made worse by the poor tactical handling and general incompetence of the Egyptian military at the time. Nevertheless, several Israeli M48s were reportedly knocked out by IS-3s. Some IS-3s were captured by Israel and later used as fixed firing points on the Bar Lev Line when their engines became too worn out. Other countries were also associated with the IS-3 in different ways. Poland and Czechoslovakia received only a few vehicles for familiarization and testing, while North Korea received a larger number after the Korean War. Iraq and Syria are also commonly listed as limited IS-3 users, and China is sometimes reported to have received IS-3s as well, although this claim is less consistently supported in detailed Russian sources.

During the Cold War, IS-3 tanks remained part of the Soviet armored force, although they gradually lost their importance as newer heavy tanks entered service. The T-10 eventually became the main Soviet post-war heavy tank, while the IS-3 increasingly moved into secondary, training, reserve, or limited service roles. In Soviet service, the modernized IS-3M remained in use into the 1970s. After Nikita Khrushchev came to power, the role of the Soviet heavy tank began to decline. Medium tanks were rapidly improving, eventually leading toward the main battle tank concept, while anti-armor weapons were also becoming more capable. Heavy tanks were increasingly seen as redundant, since newer medium tanks could perform many of the same battlefield tasks while being more mobile, easier to operate, and still adequately protected.

As a result, the IS-3, along with other Soviet heavy tanks, was gradually relegated to secondary roles. Many were sent to remote regions such as the Far East, where their heavy armor and powerful guns could still be useful against potential threats. Some vehicles were also converted into stationary firing points or bunker-style defensive positions. This was not as strange as it might seem. The 122 mm cannon remained powerful and had good range (14200 m), while the turret was one of the best-protected parts of the vehicle. As a fixed defensive position, the tank no longer needed to rely on mobility, engine reliability, or modern fire-control equipment to remain useful. A bunker does not need a stabilizer or even electrical power to do its job. A bunker also does not need an engine to do its job, so removing unnecessary mechanical components reduced maintenance and made the installation easier to keep operational. The crews would also not require the same level of training as a fully mobile tank crew, aside from the artillery training needed to operate the gun effectively. As a result, these fixed positions could be operated by conscripts, reservists, or second-line units without wasting better-trained tank crews on static defensive duties. For this reason, using old heavy tanks (and even some early T-54s) as static defensive weapons was actually a fairly practical idea. It is likely that many of the vehicles which formally remained in service until the late 1990s were survivors used in these secondary or fixed defensive roles, rather than fully operational frontline tanks. Nevertheless, the ISU-152K/M and IS-2M are known to have remained in active service as regular armored vehicles in certain exceptional cases, even as late as the 1980s. In the specific case of the IS-3M, I found evidence of the tanks still being used as regular vehicles as late as the mid-1970s. After that point, their role seems to have shifted mostly toward training, reserve duties, storage, and static firing positions. The IS-3M was officially removed from Russian Ministry of Defence service in 1997.

The above bad boy on the Shikotan island in the Kuril archipelago was probably one of the last active units in the world. When Russian forces left the islands, certain components were removed and the weapons were declared inoperable. The remaining ammunition was destroyed locally. Nevertheless, even in their poor condition, some of the tanks can reportedly still traverse their turrets and elevate their guns. Surprisingly, they are still listed as property of the Ministry of Defence and remain under conservation, which is rather amusing given their current state.

More on these Bunkers

Spoiler

The Kuril IS-3Ms, together with their sister vehicles, the IS-2Ms, were brought to the islands to cover the entrances to potential landing sites that could be exploited by the Japanese. They were a part of what the Soviets called a “Company of Tank Firing Points”. Their main role was coastal defense, with the tanks intended primarily for use against landing craft and ships approaching the shore. According to accounts of their service, these units practiced firing out to sea twice a year and reportedly achieved good results.

The tanks were probably transported to the islands by large landing ships and then driven to prepared defensive positions. Unlike some other Soviet fortified positions, they were not stripped of their turrets and placed inside full concrete bunkers, as this would have been more expensive and time-consuming. Nevertheless, they have been placed on concrete supports or prepared bases, leaving space beneath or between the tracks. This allowed the crew to enter and exit the vehicle from and to a trench or protected position, reducing their exposure to shell fragments. Once in place, their engines, transmissions, and other unnecessary mechanical components were removed, with the freed internal space likely used for additional ammunition, supplies, or crew equipment. The Israelis used a similar approach with captured IS-3Ms on the Bar Lev Line.

Early T-54 tanks, on the other hand, were treated differently. Their hulls were still useful for engineering or support roles, so the turrets were removed and mounted separately in purpose-built concrete positions closer to the water. These turret bunkers were intended to engage landing forces directly as they approached the shore. The IS-2M and IS-3M tanks shared a similar fate to their T-54 counterparts on the Sino-Soviet border. There, their turrets were installed in prepared concrete fortifications that appear to have been far more developed than the simpler positions found on the Kuril Islands. This was likely due to easier access, better logistics, and the greater strategic importance of the Sino-Soviet border.

In general, these positions were known as НТОТ, or stationary tank firing points. Groups of them were organized into РТОТ, meaning companies of tank firing points, and in larger fortified regions they could form ОБТОТ, or separate battalions of tank firing points. Turret-only concrete positions were usually called АВТБ, artillery platoons of tank turrets, or simply ВТБ, platoons of tank turrets.

Notice the interesting camouflage patterns present on some of these IS-3Ms.

IS-3M In-depth

Spoiler

The IS-3M was the main modernized version of the IS-3. It was created to keep the vehicle serviceable and correct many of the weaknesses that had affected the original production tanks. The modernization focused on reliability, communication, night operation, and practical field use.

Protection

The armor layout was not radically changed. The IS-3M retained the same general hull and turret shape, including the famous pike nose and rounded cast turret. However, the modernization increased the stiffness of the hull, which was one of the major weaknesses of the original IS-3. They did it by adding reinforcing strips to the rear plate and braces in the hull floor. This was important because early IS-3 tanks had suffered from structural problems, especially around the hull and engine-transmission area. A new access opening was cut under the gearbox and covered with a welded-on plate to increase clearance between the gearbox and the hull bottom. The tank was also fitted with rear-mounted BDSh-5 smoke charges with remote control, giving it a smoke-screen capability.

Firepower

The main armament also remained the same. The IS-3M kept the 122 mm D-25T rifled gun with separate-loading ammunition. This gun was powerful, but slow-firing. Its low rate of fire was one of the main weaknesses of Soviet heavy tanks armed with the D-25T, especially when compared to later Western tanks with faster-firing guns. Nevertheless, the 122 mm gun still gave the IS-3M very strong single-shot power. With a maximum range of around 14,200 m, the gun was not only capable of seriously damaging many armored vehicles, even by modern standards, but could also lob shells over long distances. This made vehicles armed with it useful not only as direct-fire heavy tanks, but also as improvised self-propelled guns for their time. The machine-gun armament was updated. The original DShK anti-aircraft machine gun was replaced by the improved DShKM, while the coaxial DT machine gun was replaced by the DTM. These were not dramatic changes, but they brought the vehicle closer to post-war Soviet standards.

Mobility

One of the most important changes was the replacement of the original engine installation. Compared to the current in-game IS-3, which uses a 460 hp engine, the IS-3M would receive the V-54K-IS diesel engine rated at 520 hp. This engine gave it better mobility. The engine support systems were improved as well. The IS-3M received VTI-2 two-stage air cleaners with ejector dust removal, a new oil tank with a heat exchanger and foam suppressor, and a NIKS-1 electrically driven coolant preheater. These changes were mainly intended to make the tank more reliable and easier to operate. The running gear was also strengthened, with reinforced road-wheel and idler-wheel bearing units, along with revised oil seals. The IS-3M retained the original 650 mm wide tracks. It also received mounts for two 200-litre fuel drums on the rear hull, increasing its operational range. Some tanks may have received an MZA-3 filling unit mounted in a fuel-pump box on the left front mudguard, replacing the lifting shackles seen on some vehicles. This pump was used to transfer fuel from external fuel containers that were not directly connected to the engine into the tank’s connected fuel system. The IS-3M had revised mudguards and side skirts compared to the original IS-3, which did not have side skirts at all. Most IS-3M tanks appear to have carried a box or canister of uncertain purpose on the front right mudguard. Some sources and observers treat this as one of the main visual distinguishing features of the IS-3M, although its exact function is not clear to me.

Miscellaneous

The IS-3M also received improved communications equipment. The old radio and intercom equipment was replaced by the R-113 radio and R-120 tank intercom. This was a typical Cold War modernization feature, allowing the vehicle to communicate more effectively with newer Soviet tanks and command posts. Night-driving equipment was another important addition. The driver received a night-vision device, usually the TVN-2, although sometimes TVN-1. In either case, the important point is that the IS-3M gained a low-light driving capability that the original wartime-style IS-3 lacked. To assist the driver’s night-vision equipment, an FG-100 infrared headlight was added alongside a regular blackout-covered driving light. This is one of the clearest visual indicators of the IS-3M modernization. These features made the IS-3M more suitable for Cold War operations, where night movement and coordinated maneuver were increasingly important.

A command version also existed, known as the IS-3MK. This version was fitted with additional radio equipment, including the R-112 radio and an auxiliary AB-1-P/30 power unit. As usual with command tanks, this came at the cost of some internal space and ammunition.

Specifications

Spoiler

General

Country of origin: Soviet Union
Vehicle type: Heavy tank
Base vehicle: IS-3
Modernized version: IS-3M
Factory/object designation: Object 703 for the IS-3
Crew: 4
Production period: 1945–1946
Total production: Approximately 2,300 vehicles
Service life: 1945 into the Cold War; IS-3M used in Soviet service into the 1970s
Official Russian removal from service: 1997

Dimensions and weight

Combat weight: Approximately 46.5 tonnes
Hull length: Approximately 6.9 m
Length with gun forward: Approximately 9.85 m
Width: Approximately 3.15 m
Height: Approximately 2.45 m
Ground clearance: Approximately 0.46 m

Armor

Armor type: Cast and rolled steel armor
Hull construction: Welded rolled armor
Turret construction: Cast turret with welded roof sections
Upper frontal hull: Approximately 110 mm, heavily sloped
Lower frontal hull: Approximately 110 mm, heavily sloped
Upper hull sides: Approximately 90 mm, with additional side falseboard/skirt arrangement
Lower hull sides: Approximately 90 mm
Hull rear: Approximately 60 mm
Hull roof: Approximately 20 mm
Hull floor: Approximately 20 mm
Turret front: Approximately 110 mm nominal, with much greater effective thickness due to shape
Gun mantlet: Approximately 250 mm
Turret sides and rear: Approximately 110–220 mm depending on angle and location
Turret roof: Approximately 20 mm

Main armament

Gun: 122 mm D-25T rifled tank gun
Barrel length: 48 calibres
Ammunition type: Separate-loading ammunition
Ammunition carried: 28 rounds
Rate of fire: Approximately 2–3 rounds per minute
Vertical guidance: Approximately -2° to +19°
Primary sight: TSh-17 telescopic sight
Maximum direct/aimed sight range: Approximately 5,000 m
Maximum indirect-fire range: Approximately 15,000 m

Main gun ammunition

BR-471: Armor-piercing sharp-nosed projectile
BR-471B: Armor-piercing blunt-nosed projectile with ballistic cap
BR-471D: Post-war improved armor-piercing projectile with protective and ballistic caps; best AT round
OF-471: High-explosive fragmentation projectile
OF-471N: High-explosive fragmentation projectile with screw-in nose section
3S4 / S-463Zh: Illumination rounds
PBR-471: Practice round

Secondary armament

Coaxial machine gun: 7.62 mm DTM
Anti-aircraft machine gun: 12.7 mm DShKM on turret roof
Machine-gun ammunition: Approximately 2,000 rounds for the 7.62 mm machine gun

Mobility

IS-3M engine: V-54K-IS diesel
Engine power: 520 hp
Transmission: Mechanical
Maximum road speed: Approximately 40 km/h
Road range: Approximately 185 km in basic listed figures
Suspension: Individual torsion-bar suspension
Road wheels: Six double road wheels per side
Return rollers: Three per side
Track type: Steel, small-link, pin-engagement track
Track width: 650 mm
Track links: 86 per side

Fuel and external equipment

Internal fuel tanks: Four internal tanks
External fuel tanks: Four 90-litre cylindrical tanks on the rear hull area
IS-3M rear fuel drums: Provision for two 200-litre fuel drums
Smoke equipment: Two remotely controlled BDSh-5 smoke charges on the upper rear hull

Optics and communications

IS-3M radio: R-113
IS-3M intercom: R-120
Driver night-vision device: TVN-series night-vision device (TVN-2)
Commander observation equipment: Improved post-war observation equipment, including replacement of the commander’s MK-4 with a binocular observation device on modernized vehicles

Modernization features of the IS-3M