How did the Soviets get their IS-2's so tough?

[Rokko]

Hi people,

I am playing around a little with these fellas and am utterly amazed by their stats. They carry around a huge gun, which can kill even the toughest German cats frontally from any sensible range, is extremely well armoured and yet weighs more than 20 tons less than a KT and is only a little bit heavier than a Panther. Both Panther and KT did not have an easy time knocking IS-2's out at 1200m frontally, in fact the side turret seemed pretty much impenetrable, even at 700m (at least for the 75mm/L70), while only frontally the turret and the weapon mount could be penetrated. How did the Soviets do this? How did they develop such a heavily armed, armored and yet so light armored fighting vehicle?

I do see its downsides are pretty appearent, with low speed and ammo loadout and slow firing rate, but they are still pretty damned impressive.

[Jotte]

Slooped/angled armor?

[Lethaface]

*** Slight Spoiler***

During the last mission of the training campaign was the first time I didn't fear a spotted Tiger since CM:BN. In the briefing it was mentioned and when I discovered it I had 7 T-34-85 in 2 groups covering both flanks of my Infantry assault. Then when I got the IS2's I used them to stalk the Tiger from the front and after a non penetrating 122mm hit the tiger reversed showing it's flanks to my t-34's and ISU-152's to the effect of many large hit decals. Now compare that to spotting a Tiger as the Western Allies. Sure you can take it out with sneaky flank shots or Firefly's and the like, but it's a whole different ballpark.

I also found out why Stugs were the most German produced vehicle as a 152mm AP round ricocheted away on its frontal armor (lower part IIRC). Loved that hit decal too!

[Vanir Ausf B]

Both Panther and KT did not have an easy time knocking IS-2's out at 1200m frontally, in fact the side turret seemed pretty much impenetrable, even at 700m (at least for the 75mm/L70), while only frontally the turret and the weapon mount could be penetrated.

The Panther should be able to penetrate the hull out to at least 1000 meters.

[Rokko]

Well not reliably and consistently at least. I've had one Panther literally fire almost its entire ammo loadout (37 shots) at one IS-2 at 1200m. As soon as an IS-2 is only slightly angled, its turret just shrugs off everything that comes flying at it. In fact I have noticed Panthers to refuse to shoot at angled IS-2, presumable estimating their chances of destroying it rather realistically.

[kipanderson]

Rokko, hi,

It’s all about the ballistic shape of the armour.

Look at all those curves. Good thickness of armour, but nothing great, but then rounded in all directions. Compare with the Tigers and Panther and their “box..” like wasteful... weight – wise shapes.

BTW... the Soviets the thought the King Tiger a joke . Fine gun, but laughably badly designed. By very late war they were messing about with thoughts of tanks with similar protection but around 40 tons... later to be T55.

All good fun,

All the best,

Kip.

PS. German tanks certainly did the business.. but as a result of “massive use of resources... “ With their petrol engines of patchy reliability and poor ballistic shape they were not good designs.

[Skwabie]

They do sacrifice many things for that well rounded armor you know. Mainly tight internal space which results in poor gun depression, low ammo load and physical strain on crews. Uncle of mine tried to sign up for the tank corps. They told him he was too tall. But he was only 1.65m high, that's even short for an Asian...

And yep done some fun test scenarios. IS-2 (late) in game is the IS-2M version (?) that has upper frontal armor at 120mm/60deg so even 88L/71 of the king tiger does not penetrate. Also the turret and lower frontal hull is rather thick. The 75L/70 or the 88L/56 has minimal residue energy after penetrating, requiring many shots to kill it. Long story short, in order to gain an upper hand fighting the IS-2 ya need the King Tiger.

[Michael Emrys]

It was noted following the 1973 Middle East War that Soviet built tanks still could not depress their main guns as much as Western tanks by a considerable margin. This was true even of the T-62, at the time the hottest new tank coming out of the USSR. This prevented them from assuming hull down positions in many instances. The Israelis, who used hull down positions constantly, were thus aided in killing them like flies.

Michael

[Rokko]

Still, it's quite amazing they developed a tank that could take on any of the German heavies and still have it 30t lighter than their heaviest solution. And it had a 100+ mm gun. It is my understanding that the IS-2 was the first turreted AFV with a main gun of such calibre. The best the Germans could come up with weighed 77t, had no turret and was pretty much a complete failure.

I'd really like to know what would have happened had the Western Allies encountered IS-2s in 1945 or later. Were there any in the Korean wars?

Besides, from a game standpoint I believe there is some sort of problem with them. Their centermass appears to be very high up, appearently it is right at the rear of turret where the rear machinegun is located. And that's exactly the spot the opposite TacAI aims at, which is very illogical, since this is a terrible spot to aim at and in fact, even with Crack crews, many shots will miss (I am speaking about shooting from a 90° angle at 750m here).

75mm/L48 won't penetrate there, ever. Only hope is of a round going short and hitting the upper hull, in which case it is often an instant kill. Not much difference for 75mm/L70, except these sometimes get partial penetrations on that spot.

[c3k]

IS-2 was a great tank. The Soviets have always excelled at realizing that the offensive potential of a tank should be emphasized. Their gun bore size have led the tank design world. Big gun = big boom.

They had years of practice with the drive train/chassis. It was a direct descendant of the KV series.

The drawbacks were the horrible human factors. Slow ROF, crammed compartment, etc. These matter. However, if I have 10 IS-2's and you have 4 Tigers (I's or II's), and, no matter the result of the engagement I will get 10 MORE IS-2's tomorrow and you will never get more Tigers, I will win. Maybe not today, but certainly by early next week.

The cost of production is a factor.

For that time, in that area, it was a great design.

For a counterpoint, look at how the late-war Soviet tanks performed in the various Arab-Israeli wars when they fought western designs which emphasized crew coordination factors over pure gun size. (I wonder how hot it got inside those tanks in the Sinai? Not a temperature, but how sauna-hot, coupled with the gases, the fear, the hunger, and the ops tempo of combat. An idea for a theme-park?)

The Soviets continued in that vein with their T-55/64/72 series. Small, few crewmembers, big gun, minimal crew comforts. I think the western approach has proven better (after they fixed the lamentably poor performance of the 105mm vis a vis Soviet armor) in the long run. It takes a lot of work to keep a tank running. 4 men in a tank is barely enough for all the non-shooting maintenance, etc., needed. 4 weeks in the field, with heat or a/c, chairs you can sleep in (barely), makes a difference in effectiveness. Western tanks have defeated Soviet tanks in every post-war engagement. (Hmm, Indo-Pakistan?) Results may be due to training, but that's part and parcel of the design philosophy. Shrug. Back on subject...

Tiger I was a dead end. It was the ultimate example of the early-war, slab-sided, tank taken to an extreme. The Tiger II was a similar example of the mid-war design taken to an extreme. (Think Panther on steroids.)

What good is accurate gunnery at 3,000 meters when the terrain only allowed engagements at sub 1,000 meters? And only 1/3 of your tanks could get to the battle before breaking down?

The Soviets focused with remarkable clarity on what was needed at the front and could be made cheaply and rapidly. (For a counterpoint, examine the memos and letters passed back and forth between the German Waffamt 6, their factories, and the other production facilities. The arguments were very self-centered as their forces were being ground to dust. Can you imagine Stalin putting up with that?)

Bah. Back to the game...

[Redwolf]

The King Tiger has much better front hull protection than the IS-2.

Whether you rate the front turret as better or not in the IS-2 versus the King Tiger is a matter of how you interpret the value of the fluidly shaped cast turret versus more of a straight (but angled) shield in the case of the King Tiger. A game can pick from a whole bunch of interpretations of how to rate the cast turret front in practice and obviously CMx2 doesn't tell you what it picked.

The King Tiger is more spacious which should improve crew effectivity but it drives up weight given same armor, and it has thicker armor.

It also has its torsion bar suspension which makes it even higher, adding to the amount (surface) of side armor you need, not to mention the suspension itself is heavy.

[Vark]

Why would any Soviet tank commander take up hull down positions with an IS-2? They were breakthrough tanks, designed to shrug off, or at the least not explode, when they were hit by any of the main weapons manning the forward defensive lines. You do not put IS-2's into defensive positions, if you are counter attacked their are plenty of weapon systems (57mm ATG's, SU-85/122's Il-2's direct fire artillery) that can deal with the enemy. The IS-2 prowl forward daring anyone to attack them, if they are engaged, their attackers will come off worse, as c3k said, maybe not that engagement but certainly in future ones.

It does raise a question, were most German accounts of destroying Il-2's sheer fantasy, or did they leave out crucial information? As for the AIW, the Soviet equipment got trashed because it was not fought in the way it was designed to be fought. Relentless advance, not milling about in front of tank ramps and then when you do breakthrough pausing, because you are worried you might be falling into a trap. As for heat in the desert, you'd be amazed at how the human body can adapt.

[LUCASWILLEN05]

IS-2s and the like were designed to take on and kill German big cats. Even the T-34/85 was upgunned to take on the Tigers/Panthers on even terms once they got close enough. But of course even the T-34/85's armour was not good enough to take on the Tiger's main gun and live to tell the tale. Alhough of course there were lots of T-34//85s and not many Tigers.

The Soviet decision to make changes in tank design really only came after the pasting 5th Gaurd Tank Army got at Prochorovka 12 July 1943. The Soviets may have claimed that they had demolished II SS Panzer Korps at that battle but they knew very well what the real truthwas and they did something about it.

It may have taken them a few months but, by the summer of 1944 with their upgunned

T-34s, IS-2s and other changes (like installling two way radios in every tank) the Red Army armoured forces could finally take on and often defeat the Panzers on more or less even terms at the tactical level.

[Sailor Malan2]

I know it is strictly post war, but forget the IS2. Look at the IS3 (JS3)! You will see why the Allied tank designers had a shock...

[Redwolf]

I know it is strictly post war, but forget the IS2. Look at the IS3 (JS3)! You will see why the Allied tank designers had a shock...

After WW2 the Germans dropped out of tank making and the US thought they could get away with a minimal effort. Until Jimmy Carter of all people authorized making real TANKS again.

[JasonC]

First, the IS-2 was the best tank designed during the war. The only comparable rival design in that era was the British Centurion, slightly after the war. The Panther was obviously earlier and a great tank by WW II standards, but not by post war ones. (Its gun did serve on French postwar tanks, however).

The initial Centurion design had only 3 inches on the glacis but highly sloped, like the Panther. Later models up that to 4.5 inches, still sloped, giving fantastic protection. It had a comparatively badly designed, boxy turret, which helped make room for its superior long 105mm gun(L52), but wasn't nearly as advanced as the rounded armor on the IS-2. (It also only got that great gun in 1953). The Centurion made up for it by just stacking a full 6 inches of armor plate on the front of the turret.

The side armor was nothing to write home about, and similarly for the speed and power. But its suspension system, tracks, and floatation were excellent, and it proved extremely capable in challenging terrain, despite being relatively underpowered in an automotive sense.

Israeli Centurions shot the crap out of Syrian T-55s and T-62s in the 6 day war. Syrian crews helped, but that the rival tanks on the two sides in that case are both pretty direct descendants of the best immediate post WW II era tanks (the T-55 from the IS-2, the Centurions from ... Centurions).

The US wasn't even in the game at that point. The Pershing was underpowered, and that really didn't get fixed until the M-48 Patton. At that point the US had a tank with a decent gun, armor layout, and performance, but it was still underprotected compared to either British or Russian tanks of the same era. The M-60 didn't really fix that - only its "soft systems" (fire control, optics etc) were superior to contemporary Russian stuff.

FWIW...

[Rokko]

Also, it seems to me the Germans would not have had anything in their sleeve to counter these new Soviet heavies, had the war gone on and their cities not been laid to waste. Did they not consider these new designs a great enough threat or was there simply not enough time and resources to develop a sensible answer? I am not sure the E-50 design would have been a sufficient solution.

[Sailor Malan2]

JS3 was only just post war - comparable in date to Pershing, 17pdr Centurion etc. Europe had more than caught up long before Jimmy Carter (105 Centurion, Leopard, Chieftain, etc)

[Vark]

The later German designs were perfect examples of projection, they bore no semblance to reality.

[Redwolf]

JS3 was only just post war - comparable in date to Pershing, 17pdr Centurion etc. Europe had more than caught up long before Jimmy Carter (105 Centurion, Leopard, Chieftain, etc)

Europe, yes. The US - no.

One problem here is that the British in particular were willing to go with defensive tank design. The Centurion certainly is. The Leopard 1 was an offensive tank but it really lacked in protection.

The US were not willing to invest money into a tank design that they would find satisfactory, which would have to be an all-rounder, and they had enough to do in military areas other than tanks.

I was tongue-in-cheek when I said Carter did the good tanks. What really happened is that progress in materials enabled the US to make a tank that satisfied them, and then they upgraded the whole fleet quickly.

[Redwolf]

The later German designs were perfect examples of projection, they bore no semblance to reality.

This one I attribute to materials, too.

The Germans could not make powertrains to move the things they built. The major reason why they could not is that modern materials to make more powerful engines and transmissions that last some time were not there, and even if they had the knowledge they would most like require alloy components they didn't have access to.

[Skwabie]

This one I attribute to materials, too.

The Germans could not make powertrains to move the things they built. The major reason why they could not is that modern materials to make more powerful engines and transmissions that last some time were not there, and even if they had the knowledge they would most like require alloy components they didn't have access to.

Oh the king tiger in CM sure can move with good hull and turret traverse. It's 2km/h slower than the Tiger I, but on a 500m stint back to back it wins out due to the 180 traverse at the return point. It's gonna matter in a tactical situation.

In a shootout vs the IS-2 none is able to penetrate each other's upper front. But IS-2's turret and lower hull is thinner and projects a larger area therefore more vulnerable.

I've ran some 8 vs 8 shootouts, the exchange ratio is about 1:4. Not exactly close to Abrams vs T-90s' 1:8, but close to Chally 2 vs T-90s.

The major disadvantage of CM's kingtiger I'd say is still that ugly looking 3D model.:mad::mad:

[MikeyD]

Towards the end of the war the US depots began constructing 'expedient Jumbos' out of M4A3E8 Shermans by doubling-up on front hull armor. That's 5 inches (127mm) at 47 degrees. Pretty much equivalent to King Tiger front hull. The US could have done very much more than it did to increase crew protection on Sherman. All they had to do was 1) recognize the threat, and 2) be willing to sacrifice mobility and service life for protection. Its apparent that they were slow to recognize the threat from their inadequate level of stateside replacement crew training. They simply didn't expect to loose that many tanks and crews.

[Shmavis]

All Soviet tanks were driven through a танк сауна (tank sauna ), and beaten with birch branches before combat. It's great for the circulation...and deflecting incoming fire.

[kipanderson]

Hi,

BTW..... quick note...

I have crawled around inside both T34/85 and IS2. Both are roomy by WWII tank standards. When compared to German tanks they are just fine. They also have superb all round vision. Better than a German tanks. The commander, loader and gunner all have a Mark 4 , 360 degree general observation sight. The small “turrets...” that sit on top of the main turret roof on those tanks.

The Soviets learnt their lesson with the cramped and poor vision T34/76 tanks. Starting with the KV1s turret they were very happy with their standard, three man turret design.

Now.. the drivers position in T34s of all types and the IS2... that is cramped... .

It is all relative of course, and the Soviets and Soviet trained armies I am sure did go for smaller crews. Better than larger for sure.

But by ’44, as roomy as any and better all round vision than any.

All interesting stuff,

All the best,

Kip.