IS-2 vs Panther: Math and Reality
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- Опубликовано: 2 мар 2023
- Is it true that the Panther's armour was nearly impenetrable for the IS-2's gun when angled? I discuss the theory and the practice behind this assertion and why the math and live fire test results don't always add up.
**Sources and further reading**
www.tankarchives.ca/2013/03/p...
www.tankarchives.ca/2019/02/p...
www.tankarchives.ca/2017/01/c...
Armour Branch Report on Armour Quality & Vulnerability of Royal Tiger
Armour Branch Report on Armour Quality & Vulnerability of Tiger II Turret
Armour Branch Report on Comprehensive Firing Trials against German Panther Pz.Kw. V.
Experimental Report No. WAL. 710/715 Metallurgical Examination of a 3-1/4" Thick Armor Plate from a German PzKw V (Panther) Tank
Armour penetration simulations: / @dejmianxyzsimulations...
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Designing the T-34
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Sherman Tanks of the Red Army
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But real life is like a video game, right? All that kinetic energy just disappears if the shell doesn't go through the armour, right?
I don’t know this is sarcasm or not, but the kinetic energy, while lost over time, still enough to damage anything that it hit. The bigger the shell and the faster it go, the better for it hold to it velocity and kinetic energy. For example, a 380mm shell, on paper can’t penetrate the front of an Abram, but because the sheer size of it, it can just remove anything that sit in it way and create a big hole.
@@witmanntheinfinite it is sarcasm.
@@witmanntheinfinite *Crater and send the tank rolling back a few feet.
@@witmanntheinfinite the frontal armour of a modern MBT has a steel equivalent protection value against each individual threat. Against a 15 inch shell that protection value will be less than the equivalent weight of steel as the defeat methods for APFSDS and HEAT are counter productive against such a large shell. Some parts of cold war heavy tanks could actually ping a 15 inch off however the question would be whether turret bearings and plate welds would fail.
Shells at longer distance also come in at an agle so at longer ranges they are more normalised to the plate than if they where at closer ranges. It depends on the shell though as well as some have higher velocities or lower velocities and different trajectories.
Wrong
Not wrong, but the effect is negligible. Depending on the type of shell fired from the D-25, the drop angle would be 1 degree at 2000 meters and about 3 degrees at 4000 meters.
@@TankArchives Thanks. I guess it's only for extreme long ranges indirect fire where it becomes an actual thing.
Regardless of whether a 122mm shell penetrated a Panther's armour or not, being struck by such a shell was sure to cause a bad day for the Panther's crew.
Surely the panthers upper plate is immune to a 122mm. I mean the 25kg projectile only has a muzzle energy of 7.9 mega joules, it's only the same as a 20 ton bus travelling at 60mph.
Which any tank over 20 tons would stop?
@@GreenBlueWalkthrough With the Crew being concussed or killed by shrapnell, welds cracked and probably mechanical damage.
The kinetic energy barely matters unless the penetrator is designed properly. And Russian projectiles were...Faulty at best.
Soviet shells were good enough for German armor, regardless of their quality bot being as good.
IS-2s could penetrate tigers, panthers, and even king tigers at 1500-2000 m ranges both in combat and tests. I doubt poor or faulty shells could be that successful
Thanks Peter! As a big fan of both tanks, this particular question drove me nuts with the various contradictory explanations from different sources (admittedly, haven't gotten to your book yet), especially once the math enters the frame. Nice to finally get a clear enough answer from someone who knows his stuff, the Tank Archive links helped a lot too
Greetings from Indonesia(;
Great content. Thanks for posting.
An Is2 can undoubtedly penetrate a Panther frontally but since it was so sluggish and it’s gun required so much time to reload it’s two piece ammunition. In terms of a tank to tank engagement I’d still say the Panther has the edge. Great video by the way!
Great explanation as always, fantastic!
This is a very interesting topic. I recently read professor hazells book on armour and saw Eds Video on the brittel armour problem you mentioned, but I have to say that I havnt fully understood this stuff at least for now :)
Thank you. By the way, I have recently purchased and read your T34 book. An excellent read.
Good explanation!
i know its a bit late to ask but which type of projectle u talking about?
Typically penetration curves fit armour thickness/(cos(angle)^1.4). Which would give a Panther 182mm vertical equivalent, which would explain it stopping 17pdr APCBC. The difficult question is whether all the plates were uniformly bad, if it was a good player in theory it should stop 122 at most combat ranges.
In theory yes, but the whole point of the video is that theory does accurately model the results of practical trials.
Thank you!
I think that there was more confusion than was warranted. First, using the Soviet certified penetration metrics for the D25-T would also say that it couldn't have penetrated the 185 mm turret armor of the Tiger II, but it could, and out past 1000 meters to boot. Secondly using the corrections for overmatching I've seen knock the Panther's front plate down to effectively c 125 mm thick resistance, resulting in a prediction which better predicts actual wartime performance, albeit maybe not perfectly so. Spotty German armor quality then would explain the rest.
"overmatching" does not exist
@@markcorrigan3930 What do you mean by that? That all the US Army's inclusion of T/D in their equations is wrong? (I recall this would mean the world's navies are wrong too, as these originally were equations derived for naval guns).
Is 2 could not pen tiger 2 turret in every battle betwen these two thanks you will see that is2 always used to shoot HE rounds do disable traks and trensmision of the tiger 2
@@justahumanbeing59 The IS-2's D25-T gun could penetrate the Tiger II's turret, and did out to at least 1000 meters by tests conducted at the Kubinka on a captured King Tiger. One shot even penetrated the hull, but the Soviets decided not to count that penetration as it was two close to an previous impact. Even there, the Tiger II's "impenetrable" upper hull when hit by Soviet 122 mm and 152 mm APHE rounds would crack and spall badly, sending huge chunks of metal fragments and splinters flying through the Tiger's interior which would have been very bad for both the components and the crew. This report is available online, RUclips won't allow the posting of links but if you Google it you can find it.
The 122 mm's HE rounds did far more than tear off the tracks. In testing against the King Tiger, the *very first round* shot was an HE from the 122 mm, which--as one would expect--did no apparent external damage to the King Tiger. However, on the inside, the shock wave and concussive effects were enough to break the King Tiger's transmission and to set the King Tiger on fire!
The Soviets also did tests with the 122 mm gun and smaller-caliber guns firing HE rounds against armored containers of varying thickness containing rabbits to measure the effects of concussion/shockwave on the animals. Even when the rabbits were protected by armor 240 mm (!!!) thick, c. 60 % of rabbits were usually seriously injured or killed by the blast when hit by the 122 mm (the 152 mm round was not tested, but one can only imagine how much worse the results would have been). Moreover, insofar tanks are concerned, the 122 mm had enough blast force to blow through the deck armor of most tanks, the King Tiger included, so a shell hitting the bottom of the turret would likely blow a hole in the deck on the tank.
So, at least a 1000 meters, the IS-2's gun firing its APHE round(s) could penetrate the King Tiger's turret. The hull would be more problematic, it would depend if this particular King Tiger had decent armor, or brittle armor. The IS-2 could also take out a King Tiger (or any other tank) with firing its HE round; a single hit would likely mean that one or more components on the King Tiger weren't working anymore and the crew wouldn't be in great shape either. It wouldn't matter that much where the HE round impacted either. It wouldn't need to hit a 'weak point' in the armor.
@@stewartmillen7708 so as i said it coudn t
-- Hello, Peter, I wonder if you can/know how accurate was IS-2 D25T gun? I know that there were/used to be accuracy test D25T vs 88mm, I think King Tiger tank at Kubinka test grounds, and numbers were pretty good/comparable. I wonder if you can do a short video about IS-2 gun, that many people think is a howitzer, which is not!
Thank you!
This is covered in some detail in my book. Different guns come out with different statistics, that's just the nature of machining, but even the worst guns tested hit within 90 cm of their target in the best 50% of cases and up to 130 cm for all cases at 200 meters. This is still enough to score a hit on a King Tiger sized target.
@@TankArchives - Yeah, but YT no longer let external links, but reference to your video is a good way not only to promote your channel, but also make a historically accurate statement.
Thank you!
And at long ranges you are going to have a ballistic trajectory so the shell will hit the armor at less of an angle. Or did the Soviet guns have a flat trajectory like the German 88mm?
The trajectory was very flat. The angle of descent at 2000 meters was only 1.2 degrees, that's not enough to affect the penetration in a meaningful way.
Hello Peter, I would love to know what your thoughts are regarding Lazerpig's claim of modern Russian tanks using WW2 engines?
Lazerpig is not a historian and his videos are not history. If there's a historical fact in there somewhere, I'm sure it ended up in there by complete coincidence.
It's kind of like reading Last of the Mohicans: it's an engaging fiction, but you are going to learn precious little about any real history because that's simply not the writer's objective.
@@TankArchives Thank you for getting back to me, can't say I disagree ha
What you said in this video presentation was quite true in most respects, but only up to point 7:05 when you said, quote: ‘According to studies by British and American metallurgists, German armor was quite brittle, quite prone to be over-matched and as a result, performed quite badly’….end quote.
That is barely half the truth. German armor of about 80mm thickness and over, was flawed only from about mid-1944 due to the declining alloy contents of nickel and molybdenum, substituted with chromium and vanadium. As alloy content dwindled, the margin of error in armor heat treatment, (multiple time-quenching, etc.) narrowed, resulting in the occasional faulty plate; about 50% of Panther glacis but more often in Tiger II and Jagd Tiger armor, (all of their armor, that is).
Before that, both German RHA and cast armor was generally as good or even better than Allied and Soviet armor. During the initial IS-2 vs Panther engagements even in cold weather, Panther armor performed well, despite the cold, attesting to very good quality. At the Isigny tests, one of three Panthers had good quality plates on their glacis and all three had good quality plates on their lower nose.
The reality of a 122mm projectile penetrating a Panther glacis at 2,000 meters or over, but only from late 1944, will be easily demonstrated with tested penetrating formulas. First of all, the Panther glacis thickness were more in the region of 83 to 85mm thick than the official 80mm. With an average of 84mm thick @ 55°, this gave the equivalent of 173mm against the 122mm BR-412 AP. Using Allied and German 50% gun-penetration criteria for the D-25T, (with higher penetration figures than the 80% criteria used by the Soviets) the Panther glacis would be penetrated by the said round up to a range of 450 meters range if RHA, (or 650 meters with a ground tilt of about 3°, which is close to Soviet combat experience). From December 1944 or at the latest January 1945, some BR-412B APBC were issued to IS-2s or ISU-122 or both (?). Against APBC rounds the Panther’s glacis is now equivalent to 144mm but given about 2° decent angle at 2,500 meters range, (reducing glacis angle to 53°) equivalence is down to 136mm, further reduced, with a medium flaw to 115mm, (Medium flawed Panther glacis encountered from Summer 1944. At 0.69 T/D ratio, striking at 53° the armor resistance is reduced to 85%). Ergo, the D-25T is now capable of penetrating the Panther glacis at 2,600 meter so math and reality agree. No conspiracy theories, no Wehraboo, no Ruskieboo, just plain math!
The whole point of the video is that math does not accurately model the result of practical penetration trials. If theory doesn't match practice, you can't discard the practice and insist that the theory is correct.
I hate to say it, but I agree with you on this. I've emphasized this point myself quite often in the discussion on this topic.
The theory must change in the face of evidence, not the other way around.
In My opinion IS-2 can have better chances for stopping KwK 42 projectile than Panther for stopping D-25 projectile due side armour- IS-2 side armour angled horizontally at 60 degrees can stop German 75 mm projectile. Panther side armour angled at 60 degrees can't stop 122 mm projectile.
Far better. The IS-2 was almost impervious to the Panther's Kwk 42 at 1000 meters according to a review of IS-2 engagements versus German heavy tanks done at the end of 1944. At least with Tiger Is and Panthers, most IS-2 permanent losses against these only occurred via ambush at 300-400 meters, as the gun/armor metrics would suggest.
From what I know a is2 can not penitrate a panther frontally at2000 m the round I believe would ricochet but it would caus chucks of Steele to go flying off the inside of the plate injuring or killing the crew please correct if wrong
Trials showed that a fair penetration can still take place at this range.
There are a few levels to this.
First we know now that the Soviet table is fully calculated and doesn't actually agree with period test data; 122 can penetrate a quality 200mm thickness plate at muzzle velocity according to Soviet testing. [specific Vlimits given on a doc shared by skylancer]
Second muzzle velocity is computed at 15*C; a tougher condition as it reduces muzzle velocity by ~3%.
Third penetration listed for 0 has no bearing on penetration at obliquity.
Fourth distinctly different design characteristics of penetrators for larger caliber Soviet guns. [Disproportionately smaller filler cavity, more robust shell body]
Fifth, high performance of Soviet shells against slope by the standards of the time. Especially in respect to German shells of 88mm caliber [tends to disintegrate if cap does not engage, almost irrespective of plate thickness], which have truly apalling performance.
To me these are the main points.
I fundamentally do not agree with idea that 122 has limited penetration against vertical armor.
As you pointed out in the Maus article, actual test result of this ammunition correspond to (estimated) K ~1900, which is normal, if a little good, for this type of shell. Computed tables rely on some kind of ??? often not related to real data.
I should raise that the Germans did seek a solution to their angled performance woes; developed along same lines as Soviet blunt tipped shells.*
In the navy this problem is rectified until about 30-40 degrees constructive angles, by means of secure, heavy armor piercing caps... Not so in the Army.
Additional information
Old theory of sloped performance outlined in WW2 BAAG mostly develop on basis of (poor) slope performance of 88/71 shot performance. In addition, use fixed slope effect on basis of sloped performance. This is totally not correct.
Soviet ballistic tables mislead ignorant observers because computed for 15*C perceptibly increases drag and decreases muzzle velocity. As a result, a Soviet "887" is a "914" in the UK; or a 6% improvement in KE. I don't think Soviet shot is ballistically inferior. In fact, German copy 85mm APCBC in Soviet table show inferiority.
On my own preference, I find estimates can be made like so;
Demarre K1800 cos^1.32; 'ideal' performance of [AP w/windscreen], on basis 90 T33 AP shot
Demarre K2000 cos^1.25; 'ideal' performance of [3 caliber AP w/windscreen]
*This is really specific because it refer to nose damage problem in range of around 20-55 degree, where subsurface stress strips the better part of the unengaged nose of the shell. Other dimension is explosive cavity. Metallurgy of shell (within reason) not such significant factor compared to these two points imo.
Additional information, Soviet 122 does not fire light ammunition for caliber. Soviet "blunt tipped" shells are usually heavier than contemporary APCBC ammunition.
Basically, AP ammunition without windscreen increases nose sharpness to improve aerodynamics and vertical armor penetration. As a result despite ~equal mass, length usually about 3 calibers.
AP ammunition with windscreen blunts the nose, as it is no longer ballistically relevant. The length is therefore reduced to about 2.6 calibers.
However, Soviet "blunt tip" ammunition take opposite approach; penetrator retains (or even increases) length of penetrator. The size of windscreen is curtailed in this process.
This design offers much improved performance in fatal range for basic AP ammunition [where nose kinda disappears], and while nominal performance against 0 degree plate is reduced, it also increased fragmentation significantly.* The shot simply resist deformation to unparalleled degree.
Unfortunately it has one particular weakness which is noticed most prominently in smaller caliber Soviet shot, who have large filler cavity. It has small tendency to completely obliterate the entire filler cavity on low angle hits, kinda completely taking the back off of the shot. And if you shorten filler cavity, the aggravated twisting motion it makes on slope impact, still destroy cavity.
Only solution is to remove, or basically remove (make so small it has zero impact basically) the cavity. This is true of Soviet large caliber ammunition. The US table shows 122 ammunition performance trailing off at high angle possibly because 122 filler cavity is proportionately bigger than 100, so the "blunt tipped" breaks the cavity a little by torquing it too hard.
Actually, compared to other ~3 caliber AP ammunition (without windscreen), so called "blunt tipped" ammunition does not lose performance against thick plate.
Shape is interesting as well. the "blunt" part, usually ~1/3rd by cross sectional area. Rest of penetrator, ~2/3rds by cross section, offer much sharper ogive radii. Some part is blunter, some is sharper. Amateur analyst completely fail to take this into account. This feature mostly negate subsurface stress problem in conventional pointed type.
US table which show ~220 cast penetration is also correct, but that is cast. RHA penetration more a little over 200 for 122 type at 0 degree.
Maybe I miss a few points since I do not explain in a while but it is basically this.
*It is a simple mechanism; it converted more of kinetic energy into fragmentation. Likewise, penetrator in better condition produce less fragmentation. Thus; WW2 APCR offers nominally equivalent fragmentation effect mostly on basis that it completely disintegrate on impact.
Interesting, I had never listened to explanations of how penetrations work, I had only seen simulations. I would have loved to see some german and soviet engenieers and scientifics working hard to get such guns and tanks, their methods and knowledge
It's simpler than that, the armour might be sloped but the shell is following a ballistic trajectory. Hence the shell will hit at a shallower angle than the line of sight figure suggests. Saying that statistical modelling of x could penetrate y is a complete nonsense. It assumes perfect manufacture of shell and armour, no prior battle damage, only one shot used etc. Even the weather could have a significant impact both upon muzzle bore as the metal contracts and wind drift of the projectile. Armour was never completely homogenous across a plate and certainly not across different tanks even of the same model. German tanks varied massively in quality to the extent where you wonder whether the SS master race types got the best produced kit. Even if it were entirely homogenous you'd get different results depending upon exactly where you hit the plate. It's also assumed that one penetrating hit wins, though you don't have to look too far for first person accounts of tanks still being battle worthy despite fairly considerable extra ventilation. Take Bob Crisps account of Crusader, duelled some panzers whilst his CO watched from afar. When they'd broken off his CO said he thought he'd fought them at too long a range, until he pointed out that his tank had 6 new holes in it. Also for popguns taking out big prey, there's even examples of machineguns getting through armour for whatever reason. Indeed you get the impression that people underestimate the number of hits that tanks would take before being knocked out ( whatever that means, with the right rear area support only completely burnt out tanks were not recoverable) whereas assuming that battle damage from artillery or even mere crap driving was not a issue.
The difference due to the ballistic trajectory is something like 2-3 degrees, it is not enough for a meaningful difference in performance.
@@TankArchives And as I pointed out at some length is entirely irrelevant. Try tallying up losses from a unit which kept accurate records then look at the circumstances in which they were lost. I recently read all the battle reports from a Churchill equipped unit. Whilst I didn't keep a tally the number of tanks 'lost' in the entire war to enemy tanks at a greater rage than they could penetrate them back was almost certainly zero. The vast majority of casualties were due to mines, artillery and driving errors. Though the number of tanks at the end of the war ( baring a few Mk1s which were eventually replaced) was exactly the same as at the beginning. Every single 'knocked out' tank had been recovered and put back into use.
Late war German steel lacks molybdenum. This element provides tensile strength etc. Big source was Turkey.
There are so many variables involved in AP penetration it is folly to try to predict it with math that assumes the other variables are static or do not exist.
Tsss... German enginering and industry are fault less ...
The key word is "spalling".
And armor breaking from multiple hits.
Your videos are of excellent quality
Accuracy >>> armor/firepower
I just did a video on accuracy. The IS-2 could hit a tank-sized target at a very long range. ruclips.net/video/yahQSiCCXFE/видео.html
The IS2 used diferent shells
Different than what?
Полигонные "чудеса" и их таблицы слабое доказательство
Можно ещё опираться на фронтовые испытания, там дичь куда покруче чем на ГАНИОПе происходит. Или мемуары, где вообще снаряд "Тигра" пробивает насквозь четыре "Шермана".
Eh so it depends then? which both arguments are stupid... Like yes a pathhher can bonce an IS-2 is angled like a Sherman can with a Tiger 1 I can do that in World and tanks and warthunder reliably... But was the IS-2 worthless? No because of the simple fact in a battle zone it's hard to have your armor angled perfectly all the time and t will still stand a better chance against a paner then a T-28 will even if German armor was always weaker... Honestly t reminds of of is the A-10 outadated... No because it has no replacement and having a gun that atleast woks on 90% of targets so yolu can lotter longer is still better then an F-35 hat has 4 bombs and leaves after hitting 4 ttagets that command found sitting in a office building 1000s of miles away.
The A-10 thing is a whole other kettle of fish, because anything the A-10's gun works on (read: not any reasonably armoured MBT from after the 50s, except in absolute ideal testing conditions which would expose the jet to lethal counterfire in a real engagement) is also vulnerable to a smaller, lighter 20mm gun as carried in most other US aircraft. The A-10 is a product of its times as well as a product of the DC political scene - it's great if you need something to loiter around half a day and strafe some angry beardy men with AKs and no heavy AAA or SAMs, but most other things can do the strafing part and loitering is only so relevant with tankers on call. It's utterly useless outside of a total air supremacy situation as it's vulnerable to anything else that flies, as well as any heavy AAA or SAMs whatsoever. In a peer conflict you're better off with something that can get in and out quickly with precision weapons to deal with their target from a safer distance, and while the A-10 can carry Mavericks, so can almost anything else. The A-10 is kept alive because Congress keep drinking the koolaid, the public haven't tired of "brrrrt" jokes yet, and the average grunt cares more about being able to see friendly jets overhead than the effectiveness of those friendly jets on their target (as demonstrated by the attitudes towards the RAF following Dunkirk). Even in ODS, which was about as permissive an environment as you can get while still needing to kill tanks, pretty much every other tactical aircraft the US employed in the conflict had more effect on target and less aircraft damaged or lost to enemy fire.
I never commented on this video because it already lost me at using that generic penetration table.
Your whole point is:
Calculation can’t be trusted because penetration tests showed different results.
Except there’s obviously a difference between good calculated values and bad ones.
This penetration table was built with the lowest amount of effort possible.
Instead of extrapolation, all numbers are based on a specific armor penetration factor for all shells.
Of course there’s a huge difference in projectiles types, shapes and steel qualities that can’t be used in such oversimplified fashion.
You can’t compare a 45mm AP against face hardened armor to evaluate the performance of 75mm APC against medium hardness rolled armor.
If anything it proves that Soviet calculated values are just inherently bad and have no ground in reality. Especially since penetration values for German guns do exist as they have been evaluated in firing trials.
But you are making the point that calculated values are inherently inaccurate and only penetration tests show the reality, using the most generic calculated values possible.
Germans also calculate the performance of the 88mm L71 to be 200mm at 30° or something like that, via extrapolation using DeMarre.
An obviously much closer value to reality then the 168mm in that Soviet table based on.
And even then they noted that the calculated value was lower then firing tests.
Which isn’t surprising since German Test plates decreased in hardness as they got thicker, reducing the efficiency of the steel.
Hence why you can’t use 37mm AP values for 30° to calculated the performance of a an APC round that penetrated 4 to 5 times as much armor.
You are comparing apples to oranges, here.
There is no thing as overmatch. It's made up game term that doesn't apply to the real world
Tell that to the employees of the Watertown Arsenal. "Its hardness is higher than desired if plate is to have good shock properties against overmatching projectiles." - Report No.710/485 Metallurgical Examination of German Armor from a Pz.Kw.III Tank , p.8
nice tank collection in the back! which brands are they from?
All sorts! My Scalemates has all the details: www.scalemates.com/profiles/mate.php?id=24232&p=projects