IS-3

IS-3

IS-2 No.321

IS-4M

IS-3

IS-2 No.321

IS-4M

USSR

V Rank

Battle rating:

AB	RB	SB
7.3	7.3	7.3

Class:

Heavy tank

Research:95 000

Purchase:270 000

Description

The IS-3 is a rank V Soviet heavy tank with a battle rating of 7.3 (AB/RB/SB). It was introduced during the closed beta testing for Ground Forces before Update 1.41. The IS-3 keeps the same D-25T gun as its predecessor while drastically upgrading its armour without hindering mobility too much.

Anyone familiar with the IS-2 and IS-2 (1944) will sit comfortably behind the driver's controls of this behemoth.

As with previous IS models, the IS-3 sports the same D-25T 122mm cannon, with its awesome destructive potential. Experienced tankers will know which weak points to look for on most targets, although the weapon's effectiveness increases dramatically once the BR-417D ammunition is researched, upgrading its penetration from 207mm to 230mm while retaining most of the HE filler. At 7.3 BR, the IS-3 will come up against many other heavy tanks with large, slow reloading guns, making the playing field much more even. Despite this, always beware the faster, lightly armoured targets such as the Ru 251, Leopard I, and other vehicles that can essentially ignore the IS-3's armour like the FV4005. As with the IS-2 mod. 1944, the IS-3 has a spindle-mounted Heavy Machine Gun, good for warding off strafing aircraft or deterring light vehicles.

The IS-3 once again demonstrates sub-par maneuverability, despite being relatively light for a heavy tank. It has an engine that produces a measly 671 horsepower, making the vehicle feel sluggish when attempting to initiate a turn from both standstills and when moving. Its' acceleration also leaves much to be desired, however, it does have a reasonably high top speed, and usually will reach it eventually regardless of the surface it is driving on. Fortunately, as with all late Soviet heavy tanks, the reverse speed of the IS-3 is very respectable, often allowing it the time necessary to back out of bad situations to reload or repair. The reverse gears and low forward gears allow the vehicle to climb surprisingly sharp slopes, despite what some might expect from such a large vehicle.

The most obvious changes over the previous IS tanks are of course the redesigned turret and the sharply angled 'pike' nose. The front is not only angled, but the armour is also relatively thick, with 110mm on both the top and bottom, angled at 54°-56° and 54° respectively. As with previous designs, the IS-3 has somewhat sub-par side and rear armour, and angling should be avoided. The redesigned turret is much more resilient than the older designs, with more angling, a much smaller flat area around the mantlet, and significantly thicker casting. The tank is somewhat vulnerable to trap shots and turret ring penetration - these can be somewhat negated by depressing the gun and blocking the vulnerable areas.

The IS-3 is the definition of a 'breakthrough' tank, which excels at close-range, front-on conflict where the chances of flanking are minimal and drivers can take advantage of the heavy frontal armour and reverse speed. When up-tiered, or against certain enemies with HEAT, HESH or ATGMs, IS-3 drivers should play cautiously as the tank is extremely vulnerable to high-penetration and chemical rounds.

General info

Survivability and armour

Armour type:

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

Armour	Front	Sides	Rear	Roof
Hull	110 mm (54-56°) Front glacis 110 mm (54°) Lower glacis	90 mm (0-40°) Top 20 mm (60°) Bottom	60 mm (47°) Top 60 mm (41-42°) Bottom	20 mm
Turret	250 mm (1-78°) Turret front 100 + 250 mm (9-79°) Gun mantlet	75-220 mm (33-69°)	70-120 mm (22-52°)	20 mm Front, Hatch roof 40 mm Center 75 mm Sides

Notes:

• Suspension wheels are 20 mm thick while tracks are 30 mm thick.
• The thickest armour of the tank is at the front – the "beak" at the front of the hull raises the effective thickness of the armour from 110 to around 180 – 200 mm, depending on the exact spot.
• The turret front of the IS-3 is an also fairly well armoured, with 250 mm of heavily sloped armour equating to around 400 mm effective thickness.
• Turret side armour is not equal throughout its length. In the side middle, it is 130 mm, then bordering the rear armour is 150 mm thick.
• Gun mantlet side and bottom are boosted by the 250 mm of the turret front, whereas the top of gun mantlet has no armour behind it.
• Side armour of the hull has an additional 5 mm of sheet metal on above the suspension area.
• Turret ring is 200mm thick with a 20mm "collar" covering the front and sides.

Mobility

Mobility characteristic
Weight (tons)	Add-on Armor weight (tons)	Max speed (km/h)
48.0	N/A	43 (AB)
		40 (RB/SB)
Engine power (horsepower)
Mode	Stock	Upgraded
Arcade	671	827
Realistic/Simulator	460	520
Power-to-weight ratio (hp/ton)
Mode	Stock	Upgraded
Arcade	13.98	17.23
Realistic/Simulator	9.58	10.83

Armaments

Main armament

122 mm D-25T
Capacity			Vertical guidance	Horizontal guidance	Stabilizer
28			-3°/+20°	±180°	N/A
Turret rotation speed (°/s)
Mode	Stock	Upgraded	Prior + Full crew	Prior + Expert qualif.	Prior + Ace qualif.
Arcade	7.28	10.08	12.24	13.54	14.4
Realistic	5.36	6.30	7.65	8.43	9.00
Reloading rate (seconds)
Stock	Prior + Full crew	Prior + Expert qualif.	Prior + Ace qualif.
26.0	23.0	21.2	20.0

Ammunition

Penetration statistics
Ammunition	Type of warhead	Penetration in mm @ 0° Angle of Attack
		10m	100m	500m	1000m	1500m	2000m
BR-471	APHE	205	201	183	162	144	128
BR-471B	APHEBC	205	203	191	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 in m/s	Projectile Mass in kg	Fuse delay in m:	Fuse sensitivity in mm:	Explosive Mass in g (TNT equivalent):	Normalization At 30° from horizontal:	Ricochet:
								0%	50%	100%
BR-471	APHE	795	25	1.2	19	246.4	-1°	47°	60°	65°
BR-471B	APHEBC	795	25	1.2	19	246.4	+4°	48°	63°	71°
BR-471D	APCBC	800	25	1.2	19	192.5	+4°	48°	63°	71°
OF-471	HE	800	25	0.1	0.1	3,600	+0°	79°	80°	81°

Ammo racks

Ammo racks of the IS-3.

The D-25T cannon fires two-piece ammunition that are stored all around the crew compartment. The majority of the projectiles are found lining the sides and rear of the turret while the majority of the propellant found in the hull, with two large piles flanking the driver and a few kept on the hull floor and rear. Next to the cannon breach on the loader's side is a small ready rack containing 5 propellant charges, with the 5 accompanying projectiles found to the loader's right against the turret side. The time it takes the loader to load one round into the ready rack from the stowage racks is about 21 seconds.

Full ammo	1st rack empty	2nd rack empty	3rd rack empty	4th rack empty	5th rack empty	6th rack empty	Visual discrepancy
28	23 (+5)	17 (+11)	13 (+15)	10 (+18)	8 (+20)	1 (+27)	no

• Recommended ammo load is 12, which empty all of the racks but racks 1 and 6.
• Ammo Rack 1 is a ready rack, and takes priority in being filled at the beginning of the battle, then fills racks 6 through 2.
• Full reload speed will be realized as long as ammo exists in the ready racks. If all three ready racks are empty, a penalty to reload speed will occur.
• Simply not firing when the gun is loaded will load ammo from racks 2-6 into rack 1, as long as there is ammo in racks 2-6. Firing will interrupt the loading of the ready racks.

Machine guns

12.7 mm DShK
Pintle mount
Capacity (Belt capacity)				Fire rate (shots/minute)	Vertical guidance	Horizontal guidance
300 (50)				600	-4°/+85°	±180°

7.62 mm DT
Coaxial mount
Capacity (Belt capacity)				Fire rate (shots/minute)	Vertical guidance	Horizontal guidance
2,000 (63)				600	N/A	N/A

Usage in battles

The IS-3, continuing the tradition of the Russian IS line of heavy tanks, sports a powerful 122mm cannon, strong frontal armour and reasonable mobility for its class. As with its predecessors, it excels at dispatching anything it can penetrate with its explosive-filled rounds, and relies heavily on its excellent reverse speed and sharply angled armour to keep itself out of trouble. However, an IS-3 commander will increasingly encounter HEAT, HESH and ATGMs which pose a serious threat to the vehicle.

General Gameplay

One of the most important points about the IS-3 is that angling does not work - your pike nose will become easier to get through as you angle your tank, so handle all enemies head-on, if possible. However your gun is still the same 122 mm cannon as on the initial IS-2 at which is situated at a lower battle rating, so it is understandable that you will struggle to penetrate many heavy enemies frontally now at the higher battle rating.

In the current meta, faster vehicles are more viable than heavier ones, and the IS-3 is at a big disadvantage especially in Realistic. Your armour is amazing in a downtier (to Battle Ratings 6.3 / 6.7), but it's basically non-existent in an uptier (to Battle Ratings 8.0 / 8.3, where you start seeing APFSDS and HEAT shells all the time), so knowing when to take this tank out is also a big part of gameplay with it.

Arcade Battles

Surprisingly, the IS-3 can do very well in Arcade. Many enemies in Arcade don't seem to know that the best way to kill the IS-3 with a conventional round is via a shot-trap, so your survivability is increased. Moreover, when fully upgraded, the IS-3 becomes extremely mobile in Arcade allowing you to get into cover after shooting, or quickly advance on an unsuspecting enemy. The best strategy against a single enemy is to just rush them - the terrain usually bounces your tank around slightly making it very difficult to penetrate, and the sheer sight of a heavy tank speeding towards the enemy will cause some panic.

The more experienced tanker will know when to take the IS-3 out in battle and when to use other vehicles. If you know that the game is an uptier (e.g. by checking the statistics tab, or by the map draw) you should decide against the IS-3 and take out a tank like the BMP-1, which fits better into the high tier meta. Also, long-range engagements are a gamble, since your top round and long reload times make it difficult to successfully attack enemies, while they might have a HEAT shell that disregards distance. However, the rush strategy can work here as well, especially if you turn your tank in random directions once in a while, making it harder for opponents to aim at you.

Realistic Battles

In Realistic, the IS-3 is much more difficult to play, because enemies take more time to aim at weakspots and your mobility is toned down. Due to that, you need to take time with your own shots and know your opponents - is there an ammo-rank in the side of the Caernarvon, or should you shoot at the driver's position? and etc. Generally, you need to play with stealth in Realistic, because the person who shoots first is usually the one that gets the kill. Flanking can, and does, work with the IS-3, not because of speed, but because your teammates are shot and you can return fire at the perpetrators and continue your advance. Moreover, some light tanks that are prevalent at the higher Battle Ratings outright cannot penetrate you with their main guns (most of them have ATGMs, though).

Against ATGMs, it's a good idea to use your machine guns to shoot at the ground in front of your tank - this makes a small smoke-screen out of dirt and rubble that makes it difficult for enemies to aim their ATGMs. Keep in mind though, that you should still move your tank away from the initial position, because enemies will try to predict where you are going (it's a good idea to shoot machine guns increasingly to the left, while moving to the right, because it causes a sense of your tank moving with machine guns, while actually, you're moving in the other direction).

General Tips

The IS-3 is relatively versatile, but excels in close-range combat against conventional rounds - it is very good at taking on other heavy tanks such as the T32 and Caernarvon.

• It has reasonably decent top speed, and on solid ground, acceptable acceleration, allowing it to reach cap points and combat areas fairly promptly and set up in positions to allow it to make the most of the frontal armour.
• When down tiered (6.3-6.7 games), the IS-3 performs excellently, able to push forward and play its 'breakthrough' role with impunity.
• Good climbing capabilities allow the IS-3 to reach some surprising positions for sniping or supporting teammates pushing points. Despite the gun's effectiveness being reduced at the range, the armour of the vehicle becomes much more effective as weak spots become significantly harder to hit.
• Since the IS-3 can keep up with most medium tanks like the Centurions, Panthers or T-44s, it can be played as early-game heavy support for those lighter, more vulnerable hulls to assist in taking objectives.
• In up tiered games (7.7-8.3), the IS-3 can come across a lot of chemical rounds and must be played significantly more carefully, as its armour simply cannot compete with the high penetration of these rounds.

Play this tank almost any way that is favourable. A few tips to increase this vehicle's performance:

• Always face towards the enemies directly, avoid exposing the weak hull sides.
• Cover the frontal weak spots if necessary with the gun's large barrel by pointing it downwards. It's better to have the gun barrel destroyed than it is to lose crew members and be potentially unable to reverse out of bad situations.
• Stop only to fire. Movement makes the weak spots harder to target. Even when there is no destination to move to, go back and forth a few meters just so that the IS-3 hull wobbles a bit on start and stop.
• Plan aggressive pushes and movements around enemy locations. The gun has negligible depression and very bad horizontal traverse, making reacting to enemies slow and risky, and impossible if they're on lower ground.
• Avoid engaging vehicles over hills by climbing the hill as it will be hard to aim with only -3° depression and the lower plate will be vulnerable due to the angling.
• Avoid fighting tanks with HEAT/HESH/APFSDS.
• Be careful when brawling at extremely close ranges, as the top of the turret is quite vulnerable due to the vehicle's low profile.
• Avoid facing elevated opponents, as this decreases LOS thickness for hull and exposes turret top.
• Carrying less ammo helps increase survivability from penetrating shots to the turret (ammunition is spread around the edges of the turret).

The Stock Grind

This vehicle can be a pain to play when stock, because enemies will try to kill you in any way, often by setting you on fire 3 times in a row. Your tracks and gun barrel are frequent targets as well, and without Parts or FPE gameplay is going to be painful. 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 get shot more instead of 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.

Modules

In tier, I, Parts and Horizontal Drive should, of course, be the prioritized modules for repairs and turret traverse speed. These two will also unlock Tier II modifications and grant access to the very vital FPE and M61 shot, the former for preservation against fires and the latter to improve damage in the battlefield.

Then in tier III, Crew Replenishment should be obtained for crew survival improvement and the APCR T45 shot for improved armour-piercing power. After that, everything else could be done at one's own priorities, but Engine should be invested for better automotive performances and M89 for the smoke capabilities.

Pros and cons

Pros

• Very good frontal armor. Upper and lower plates are basically immune to all conventional shells.
• First Soviet heavy tank that comes with the V-shaped hull and ridiculously strong spaced armor lining the sides.
• Really strong turret. Even the sides of the turret are heavily armored and angled.
• Very powerful 122mm gun. Top APHE shell has high penetration and very good damage potential.
• Good top speed and maneuverability.
• Fearsome reputation. Hardly any tank will want to trade shots or brawl with an IS-3.

Cons

• Horrifying reload speed. Despite the armor, fighting two tanks at once is not advised.
• Armor is still no match for APDS and HEAT.
• Terrible gun depression. Finding a good hull down location to use the gun and good turret is difficult.
• Despite the good turret, the left side of the gun mantlet can be penetrated by conventional rounds with good penetration. (Like the 88mm shell found on the Tiger II)
• Bottom of the gun mantlet is an infamous shot trap.
• While a small target, the entirety of the turret ring is exposed.
• Ammo is strewn throughout the entire crew compartment.
• Only 4 crew members in a small crew compartment. Any APHE shell that penetrates will likely knock out the entire crew.

History

Development

Late in 1944, development of the next generation of the IS heavy tanks started, following after the IS-2 tank. The tank was to be better in armour compared to the IS-2 as a response to the new Tiger II that showed up and is able to penetrate the front armour of the hull. The project was codenamed Kirovets-1 and was headed by General Nikolai Dukhov. Design bureaus at the Chelyabinsk Tractor Plant "Tankograd" (ChTZ) and Factory No. 100 worked on the design of the vehicle. A focus on the armour improvement came from a study by an engineer in the teams that most tank losses occurred from hits to the front turret, with the front hull coming in second. The two design bureaus came up with their own ideas on how to make the armour of the tank more effective, with ChTZ developing an extremely rounded turret and No.100 developing a new angled front armour in a shape of a "beak". Soviet command decided that the design should use both features in the armour as both ideas were promising. The prototype vehicle was then produced at ChTZ and completed in October 1944 when it trialled and accepted for production as the IS-3. Production for the IS-3 started in 1945 at ChTZ alongside the IS-2 production. As the first tanks rolled off production lines, it was determined that the design was rushed and unproven with its multiple mechanical problems, some of which included the armour plates welds cracking open from the vibration of cross-country movement and muzzle blast from the gun. Because of this, the IS-3 was not available in large numbers to be committed into battle, leading to their absence in the final months of World War II before Germany surrendered in May 1945.

Despite its rough introduction and prevalent mechanical issues, the IS-3 continued production with gradual fixes to the front hull, final drive, and engine mounts. The Chelyabinsk factory produced IS-3s from 1945 to 1951 for a total of 1,800 tanks.

Usage

Though the IS-3 was not available in large numbers at the start, the Soviets attempted to transport the IS-3 to Germany in April 1945 to assist in the fightings, but they arrived too late to be committed to any fighting. It is reported that the IS-3 did see service during the Soviet invasion of Manchuria in August 1945 to fulfil Stalin's promise in the Yalta Conference to invade Japan after the capitulation of Germany, however not much information is present about this topic.

The end of the most destructive war in history did not waver the Soviet's opinion of the IS-3 however, and the Soviet command had the 52 IS-3 tanks from the 2nd Guards Tank Army paraded in the Berlin Victory Parade on September 7, 1945. The reveal of the IS-3 in the parade came as a huge shock to the Western Allies who saw the IS-3 as a nigh-invulnerable breakthrough tank with their heavy armour. The response to the tank was there to develop their own heavy tanks able to do the same job and with a gun able to fight the IS-3, such as the British Conqueror and the American M103 heavy tanks. Despite its very ominous stature, the IS-3 was still plagued with mechanical issues at this point with its poor armour quality and mechanical reliability. A short modernization program from 1948 to 1952 was made to fix these issues with tanks in production and in the depots with no change to the name designation. The IS-3 was then modernized further in the 1960s to keep it up with changing times. The modifications done were similar to the IS-2M, which gave the IS-3 extra external fuel tanks, storage bins, and protective side skirts as well as an improved engine, engine filtration, new radios, new machine guns, new gun optics, and many more small changes. The modernized IS-3 was named the IS-3M.

One of the few actions the IS-3 saw in the post-war era with the Soviet Union was in 1956 during the Hungarian Revolution with a single heavy tank regiment. The Soviet's heavy tank regiments used to consist of 21 heavy tanks during World War II. In 1947, the regiment composition is changed to between 44-46 heavy tanks and 21 heavy assault guns in a mixed formation. Another change between 1958-1959 saw this mixed unit changed to consist of only heavy tanks but now consists of up to 100 heavy tanks. Despite their armour, a number of heavy tanks were lost before the Soviets were able to crush the revolution. The IS-3 after that did not see much action afterwards in the Soviet Union's hands before it started to be replaced by the newer T-10 heavy tank in the 1960s. During this time, many heavy tanks were transported to the border between the Soviet Union and China in face of the rising tension between the two countries.

The IS-3 would also be supplied to the Soviet Union's allies such as Poland, Czechoslovakia, North Korea, and Egypt. Poland and Czechoslovakia never adopted the tank after trials however, thus leaving only North Korea and Egypt as the main foreign users of the IS-3. The Egyptians used the IS-3M, 100 of which were received from the Soviets, against the Israelis in the Six-Day War in 1967. Of all the tanks used in that war, the IS-3M was the most feared by the Israelis due to the thick front armour. Israeli infantry's standard anti-tank weaponry could not penetrate through the front, and tanks as modern as the M48 Patton also could not defeat the IS-3M. Nevertheless, the better tactics and training among the Israeli tank units were able to prevail against the IS-3M, with the IS-3 being commented by the Egyptians for its low rate of fire and outdated fire-controls to the crew's deficiency in combat. Of the 100, 73 tanks were lost during the Six-Day War. The Israeli managed to capture a number of IS-3 and pressed them into service, though only for a short period before its faults become more problematic than its benefits. The engine on the IS-3 proved to be unsuitable in the desert climate of the Middle East, and an attempt by the Israeli to alleviate this by replacing the engine with one from the T-54, though this did not prove fruitful. In the Yom Kippur War in 1973, both the Egyptians and Israeli used the IS-3M to a smaller degree than the Six Day War, the IS-3 not seeing much combat in the Egyptian forces and were used as dug-in pillboxes on the Jordan River by the Israelis.

Decline and Discontinuation

With the introduction of the lighter and more mobile T-54 main battle tank in the 1950s, the IS-3 saw less usage among the Soviet front-line as it started to become obsolete. Further development to improve and continue the IS tank series became the IS-4, IS-7, and the T-10 tanks. However, in 1960, Nikita Khrushchev, the new premier of the Soviet Union after Stalin died, ordered heavy tank production to be terminated in wake of a new military strategy of missiles rather than conventional forces. His orders are not without reason, heavy tanks are difficult to maintain and transport across the huge Soviet Union, which also did not have many bridges that could support a heavy tank. Another reason was the changing anti-tank technology that made tank armour extremely vulnerable, especially against the new anti-tank missiles that are becoming more and more efficient at their task in destroying tanks. Still, the order did not mean the dissolution of heavy tank units as by 1978, there were still up to 2,300 heavy tanks in the Far East. To this day, many heavy tanks are still either in inactive reserves or dug in as pillboxes along the borders of the Soviet Union. The heavy tank's place in the Soviet Union's military was replaced by the main battle tanks (MBT) like the T-64, which presented a much better firepower, armour, and mobility for only a weight of 35 tons, a technological sign on the rising prevalence of the MBT.

In-game description

In spite of the fact that the IS-2 lived up to expectations, a decision was made a year after the end of the war to create a tank with even higher characteristics. Its unique welded hull and cast turret construction significantly increased its armour strength in comparison to the IS-2, from which it took many key parts and components.

The hull was welded together from rolled armour plates and contained no cast armour pieces. The dual-sloping inclined nose design allowed a driver's hatch to be placed in it, significantly improved visibility in the field, and provided high armour strength to the frontal hull. For increased fire safety, its fuel tanks were moved from the fighting compartment to the engine compartment. It was armed with a 122 mm D-25T cannon with a coaxial 7.62 mm DT machine gun. The turret's roof was equipped with a 12.7 mm DShK anti-aircraft machine gun. It had no bow or rear machine guns.

At the beginning of their deployment, a range of flaws resulting from a number of design errors and miscalculations was revealed in these tanks. Among other issues, these included failures in the engine, gearbox, and parts of the armoured hull in the region of the engine compartment. In 1948-1952, all IS-3 tanks were reworked and modernised. The engine brackets were reinforced, the gearbox fixings changed, the underturret plate strengthened, the main friction coupling design updated, and the sealing enhanced on the final drive and road wheels. The 10-RK radio set was replaced with the 10-RT radio set. These changes increased the tank's mass to 48.8 tonnes.

The first experimental group of IS-3 heavy tanks left their factories in 1945. In total, 2,311 of them were made by mid-1946. They were not deployed in combat in the Great Patriotic War. There are some indications that the IS-3 was used in the defeat of the Japanese army in August 1945.

Media

• Skins and camouflages for the IS-3 from live.warthunder

See also

Links to the articles on the War Thunder Wiki that you think will be useful for the reader, for example:

• reference to the series of the vehicles;
• links to approximate analogues of other nations and research trees.

External links

• [Vehicle Profile] IS-3