tag:blogger.com,1999:blog-5030145265861917845.post7840921050654415431..comments2024-03-28T14:35:30.147-04:00Comments on Tank Archives: None More Frightening than the CatPeterhttp://www.blogger.com/profile/09622237223229485503noreply@blogger.comBlogger50125tag:blogger.com,1999:blog-5030145265861917845.post-82939545608829697472019-05-26T16:05:54.861-04:002019-05-26T16:05:54.861-04:00@ Stewart Millen
I didn't bring up Bird & ...@ Stewart Millen<br />I didn't bring up Bird & Livingston values as I don't use them.<br />What my original comments were that the ranges stated for the 122mm and 100mm penetration of the Panther were wrong. As you can see when you compare the given velocity m/s of numbered hits in the 1944 King Tiger test to their assumed ranges. (You don't need to read Russian. Just read the numbers.) Then compare that velocity to the 1957 firing table. For example: hit #33 122mm pointed AP 662.6 m/s is 2400 m range. But in a 662.6 m/s impact the range would actually be 1062 m by the firing table in the 1957 document.<br /><br />BTW, the Tiger II didn't have high hardness armor. It was rather soft. Russians used high hardness armor. Mobiushttps://www.blogger.com/profile/05256982406940327658noreply@blogger.comtag:blogger.com,1999:blog-5030145265861917845.post-10019021596265261232019-05-25T12:55:38.153-04:002019-05-25T12:55:38.153-04:00Unfortunately, Mobius, I don't read Russian, a...Unfortunately, Mobius, I don't read Russian, and can't copy-and-paste into Google for a crude translation, and I looked for this claim about T/D. Not doubting you, just didn't/couldn't.<br /><br />However, this report does describe the testing on the King Tiger, with detailed hit-by-hit description by each round. Here again, you see penetrations of the 122 mm where the Bird/Livingston penetrations predict none possible, even though the thickness of both the King Tiger turret (185 mm) and upper hull (150 mm) are considerably greater than the size of the penetrating rounds (122 mm, 100, and Kwk43 88mm), while the Soviet 152 mm round barely just matches the Tiger's hull thickness. So overmatching of the King Tiger's high-hardness rolled armor cannot be the cause of failure in this instance.<br /><br />I know outliers exist, and in empirical formulas like Kruppa and DeMarre you'll always have them. Again, to me it seems to explain things better if you used the 1957 ballistic table you propose and a point-blank value of c. 225 mm or mroe for the BR-471, and 4 % higher than that for the BR-471B. I'd also think the Kwk43 point-blank value should be about ~ 222 mm or so and all other German values should be at least 5 % lower. I have plugged these values into the WW2 gun and armor calculator and everything seems to make sense (save penetration #4 on the Tiger II hull, by the 122 mm, which I'd just accept as an outlier). <br /><br />I also note when you take the 1957 ballistic data you propose, and match it in the DeMarre equations against the German 128/L55, which is the closest equivalent and its velocities and rounds, then you get c. 220-230 nm predicted penetration. So it's not like there is no theoretical justification either.<br /> Stewart Millenhttps://www.blogger.com/profile/01261690405884935161noreply@blogger.comtag:blogger.com,1999:blog-5030145265861917845.post-79456667017872999012019-05-23T19:27:48.757-04:002019-05-23T19:27:48.757-04:00I wonder about the ergonomics versus armor thickne...I wonder about the ergonomics versus armor thickness issue. Chieftain often complains that tanks, like the T34, are cramped, and therefor hard to operate efficiently. As a tanker, I'd take a cramped compartment over a "roomy" one any time, since it means more armor thickness as a tradeoff. Also, short tankers in general used to be chosen over their taller comrades, similarly in the Submarine corps. The Panther is a great balance of attributes, but its height, in my humble opinion, is one of its definite weak points. The greater the cross section, the greater change of being hit, especially when trying to fight from defilade. Same with the M4 Medium (Sherman). The British and Russians, in particular, seemed to understand that smaller is better. I guess the Germans were just a larger "Arian stock."Princeofcupshttps://www.blogger.com/profile/10420271807829509319noreply@blogger.comtag:blogger.com,1999:blog-5030145265861917845.post-20016900755912553832019-05-23T19:12:26.793-04:002019-05-23T19:12:26.793-04:00I found the source of the 1944 incorrect firing ta...I found the source of the 1944 incorrect firing tables.<br />Page 6 of this report.<br />https://mega.nz/#!XO5mAILR!kwFgFDmDdsHEdFb3tk0oI7t8Kfx9PkP8Zeo-qfldKTw<br /><br />In tests High hardness armor had an advantage over RHA in T/D ratio of 1.10 or more. It was distinctly inferior when T/D was 1 or less.<br />Mobiushttps://www.blogger.com/profile/05256982406940327658noreply@blogger.comtag:blogger.com,1999:blog-5030145265861917845.post-85381718484791098462019-05-20T13:32:32.461-04:002019-05-20T13:32:32.461-04:00@ KillaKiw
Quick drive-by comments.
1) The Panth...@ KillaKiw<br /><br />Quick drive-by comments.<br /><br />1) The Panther's turret (at least the mantlet; which composes the fast bulk of it) is not weaker than the hull, it's actually stronger (caveats thrown in). That's because the median angle of impact of any incoming round will be about 50 degrees to the vertical; though the Germans appear in their WaPruf1 October 1944 calculations appear to have used 45 degrees as the median angle. (They also seemed to have used 35 degrees as the median impact angle for the IS-2 model 1943 and T-34/85 rounded surfaces, which is close to what I assumed too). Yes, about 10 % of incoming rounds will be less than 15 degrees, and have minimal slope enhancements, but on the other hand about 20 % will hit at an angle of > 65 degrees. That, and the fact that the mantlet is thicker and less overmatched by the 122 mm then the hull, means that a penetration is less likely there than on the hull.<br /><br />There are small 100 mm thick areas around the mantlet, minimally sloped, which are vulnerable to lots of things, but then again there's this 300 mm ring around the gun which is invulnerable to almost anything WWII.<br /><br />2) Soviet armor was harder, but less brittle, than the softer German plate, because they used superior alloys. There were some problems on early IS-1s and IS-2s with non-penetrating spalling, but on the whole Soviet armor had a minimal risk of cracking/spalling/breaking compared to German plate. I have seen lots of pictures of knocked-out IS-2s, and a couple really shot up, but the only cracks or irregular holes I have seen in them are where edge effects may have played a role (like near a gun port). Peter has published on this site a Soviet analysis on the spalling associated with hits of their own knocked-out tanks, and only about 2 % were affected (by memory). <br /><br />German plate, despite being less hard, when bad tended to crack or even shatter like glass. <br /><br />I think the failure of the Kwk43 to penetrate was simply it didn't have enough penetration. As I said, I recall figures published back in the 1970s having a penetration of 207 mm at 500 meters, not 219 mm, as the Bird/Livingston translations of German testing has. As the Germans cherry-picked their rounds for their tests, if one assumes a +/- 10 % variance of the results, what you do is that you throw out all the lower-than-average scores and the "low" figures are what would have been your "average" if you had not done that. I think the point-blank penetration of the Kwk43 is more like 220 mm instead of 235 mm. Stewart Millenhttps://www.blogger.com/profile/01261690405884935161noreply@blogger.comtag:blogger.com,1999:blog-5030145265861917845.post-28852969012687711192019-05-20T13:09:33.353-04:002019-05-20T13:09:33.353-04:00Mobius
A remarkable feat as the corrected tables...Mobius<br /><br /><i> A remarkable feat as the corrected tables of the DDR only gives their own D-25T a 123mm @ 90° penetration at that range. </i><br /><br />Using what penetration criteria? The data in this table looks similar to the Soviet 80 % penetration data, just a little lower, which would be expected if you lowered the muzzle velocity from 800 to 780 m/s.<br /><br />And, judging from what I can read from the top, it's the BR-471 round. <br /><br /><i> So the 88mm cannot penetrate 140mm @ 60°. Good catch. Go tell Captain Obvious. </i><br /><br />You've misunderstood the data. Two tests were done against the IS-3 upper hull plates; the 900 m penetrations were achieved at 40 and 320 degrees, to the right and left, respectively, in an apparent attempt to remove the horizontal slope component of approximately 18 degrees of the "pike" nose. The 200 m penetration was *also* against the IS-3 upper hull plates, but done head-on, at zero degrees, to include both vertical and horizontal slope components. Both penetrations seem to fit at least the British/US definition, so the penetration definition there matches Livingston/Bird (which was I asked Peter).<br /><br />The Kwk43 failed to penetrate the same upper plates in both tests, even though in theory from Livingston/Bird it might have succeeded in the tests done at 40 and 320 degree horizontal angles. So the Soviet gun overachieved the Bird/Livingston data while the Kwk43 underachieved. <br /><br />The 701 hull tests (140 mm @ 60 degrees) had both guns failing to penetrate, as would be expected. You confused this test with the others.<br /><br /><i> This is not my penetration formula but is the Russian ARTKOM DeMarre formula. Look at all the ARTKOM tables and it shows they were calculated with K=2400 factor. But it probably doesn't work for angles over 30 degrees. </i><br /><br />*Forget formulas*. Look at those holes in the armor, according to you there should be no holes. Also note the scuff marks made by the Kwk43 where their *might* be a hole in the angled tests. <br /><br />The purpose of engineering formulas is to model and predict real-life experiences, not vice versa. Both the Bird/Livingston data and your reductions of it fail to predict this event. Nor would the testers of the IS-3 hull tests be motivated to press their thumbs on the scale in any way to rig these tests; they were trying to develop an impenetrable IS-3 or IS-4 hull, not to prove that the 122 mm was the world's best anti-tank gun. So these tests say, to some extent, they failed.<br /><br />This weekend I played around modeling this. If you assume these tests provide a better view of reality, and I can't see why they don't, then if you use the reduced velocities you advocate but also use these tests as a basis for an indication of the penetration of the D25-T at a range of zero meters @ 780 m/s, you get a model that seems to predict the observed reality pretty well. Now penetrations of the BR-471 round on the Panther's hull extend out further, not just a bit past c. 1500 meters according to Bird/Livingston but past 2000 meters, as the Soviets observed, but there is a range between 600-1100 meters where round shattering is predicted to be likely. And it was failure to penetrate at these ranges, of course, was a reason why the BR-471B was developed. <br /><br />I then also tried it on the Tiger II. The model seemed to match Soviet testing pretty well on the turret (500 meters max with the BR471, a bit further on the BR-471B). It wouldn't predict the failures of the Tiger II hull observed but the Soviets noted those appeared at the weld seams, which would be hard to model and not representative of the whole hull.<br /><br />Consider it a 'hypothesis'. Stewart Millenhttps://www.blogger.com/profile/01261690405884935161noreply@blogger.comtag:blogger.com,1999:blog-5030145265861917845.post-82957075578672932942019-05-19T18:01:38.190-04:002019-05-19T18:01:38.190-04:00Here's the deal 2:
Penetration doesn't mea...Here's the deal 2:<br />Penetration doesn't mean everything.<br />A 88mm APCBC shell penetrates a lot of vertical armor because it "pierces" the plate. At least if we are talking about ductile armor. Piercing is very efficent in defeating armor, hence why APCBC shells, that have a cap to prevent the nose from deforming, can defeat plates at low obliquity very well even at high velocity. Plain AP shells generally can not pierce thick plates because at high velocity the sharp nose of AP shells will deform or break, lowering the effectivness of the shell to defeat the armor. Very hard armor offers great resistance against piercing. However since hard armor is generally more brittle it will break appart instead of deforming like ductile armor.<br /><br />Highly sloped armor is also unaffected by the piercing ability of AP shells, hence why APC shells have no advantage against such armor. The armor is simply defeated by the kinetic energy of the shell deforming or breaking the plate.<br /><br />An 122mm AP shell fired at 795m/s should have no or only a slighty advantage against 88mm APCBC shell fired at 1000m/s against sloped armor at 60°. Yet the 122mm defeated the frontal armor of the IS-3 while the 88mm couldn't. How is that possible?<br />The only explantion is that the armor in the test was of very high hardness which made the armor easier to defeat by a large heavy shell that shattered the armor using its momentum.<br />If we compare the numbers we see that both rounds defeated the plate at a velocity where both rounds roughly had the same momentum per area. Since the 122mm is much heavier it required less velocity to break up the armor and push it out of the way.<br />If the armor was of low to medium hardness, and therefore more ductile, neither shell would not be able to defeat the armor.<br />When the 122mm was tested against the cast front armor of the M48 medium tank, the shell could not defeat the 110mm sloped at 60° even from close range.<br />So the 122mm shell only has an advantage over the 88mm when fired against brittle armor that is easier defeated by momentum instead of the KE energy required to pierce and deform the plate.KillaKiwihttps://www.blogger.com/profile/04760488116137443661noreply@blogger.comtag:blogger.com,1999:blog-5030145265861917845.post-65438859394050664132019-05-18T18:32:39.994-04:002019-05-18T18:32:39.994-04:00@Steward Millen
I had to look up elsewhere what ar...@Steward Millen<br />I had to look up elsewhere what armor thickness you are assuming. All I have in that article to go on are penetration distances. <br />I guess object 701 had 140mm @ 60° and JSIII had 100mm @ 60° though they are prototypes so who knows?<br /><br /><i>The upper front plate of the IS-3 hull can be penetrated by 122 mm sharp-tipped shells from 900 meters. </i><br />A remarkable feat as the corrected tables of the DDR only gives their own D-25T a 123mm @ 90° penetration at that range.<br />http://www.panzer-war.com/Images/DDR-DSC01APC.jpg<br /><br /><i>Data on the resistance of hulls to shells is provided in tables ## 8, 9, and 10."</i> ??? Apparently missing...<br /><br /><i>The factory #200 hull exhibits similar properties. No guns can penetrate the upper front plate, at any distance or tested angle.</i><br />So the 88mm cannot penetrate 140mm @ 60°. Good catch. Go tell Captain Obvious. The Yugo tests came out at least 10 years ago and they showed it couldn't penetrate 101mm @ 60° of 290 BHN armor.<br /><br /><i>The IS-3 tests show penetrations using the 122 mm gun, both BR-471 and BR-471B rounds, when there *should be no penetrations at all* even at *point-blank range*</i><br />This is not my penetration formula but is the Russian ARTKOM DeMarre formula. Look at all the ARTKOM tables and it shows they were calculated with K=2400 factor. But it probably doesn't work for angles over 30 degrees.<br />Mobiushttps://www.blogger.com/profile/05256982406940327658noreply@blogger.comtag:blogger.com,1999:blog-5030145265861917845.post-33824923102940521642019-05-18T15:48:46.091-04:002019-05-18T15:48:46.091-04:00Thanks Peter, for the clarification.
Looking at t...Thanks Peter, for the clarification.<br /><br />Looking at the holes in the front of that IS-3 pike nose (upper glacis plate) by 122 mm rounds, it seems to fit at least the British definition of penetration--these seem to be complete holes through the armor, though they of course don't indicate how much of the round went through. If that's so, these tests do conflict with the Bird-Livingston data, which have the upper limit at 197 mm for BR-471 and 205 mm for the BR-471B against vertical, homogeneous, plate. <br /><br />Assuming that the 320 and 40 degree tests were done to eliminate the horizontal slope component from the plate (about 18 degrees), after doing that the effective armor penetrated is 110 mm @ 55 degrees (US army equivalent slope multiplier of 2.1) so it's 231 mm; overmatching knocks this down to 210 mm for the BR-471 round. So this is 210 mm horizontal plate penetrated nominally at 900 meters--Mobius can argue that this stated range really represents a range of less than 900 meters, but even if it was done point-blank it's a deviation.<br /><br />The frontal 0 degree test including the horizontal and vertical components of slope (again, using US Army factors) predict like a 240 mm equivalent of vertical plate; overmatching by the 122 mm BR-471B round knocks this down to 218 mm but you get at penetration by at least British/US criteria at 200 meters. Same caveats about range apply. <br /><br />Meanwhile, the Kwk43 shells (235 mm penetration at point-blank range by the Bird/Livingston translations from German tests) should go through the front upper plates at 40 and 320 degrees (or come close to doing so) but seem to be completely rebuffed. <br /><br />I've always thought the Bird/Livingston values for German guns was at least 5 % high; this is in part I remember seeing the values for these guns back in the 1970s, in S&T magazine and elsewhere, that were lower by about--5 %! That obviously didn't come from the Soviet data you posted, nor could it be German, so it likely was from US/British testing done on captured weapons. This is consistent with the British/US tests being done with captured German ammo as-issued as opposed to cherry-picking rounds like the Germans did. <br /><br />But these test also suggest the penetration data for Soviet guns by Bird and Livingston is low, or at least the 122 mm. <br />Stewart Millenhttps://www.blogger.com/profile/01261690405884935161noreply@blogger.comtag:blogger.com,1999:blog-5030145265861917845.post-89789022263475085232019-05-18T14:05:46.601-04:002019-05-18T14:05:46.601-04:00I've always taken "can be penetrated"...I've always taken "can be penetrated" as the PTP criterion (rear of the armour is compromised in some way) and "reliably penetrated" as PSP (complete penetration, round passes through the plate). Meanwhile, the Western (at least British) standard of penetration is that light can pass through the plate, so somewhere between PTP and PSP. <br /><br />PTP is often matched to 20% penetration chance and PSP to 80% penetration chance.Peterhttps://www.blogger.com/profile/09622237223229485503noreply@blogger.comtag:blogger.com,1999:blog-5030145265861917845.post-35637834883312430872019-05-18T14:02:16.646-04:002019-05-18T14:02:16.646-04:00Mobius,
The IS-3 tests show penetrations using th...Mobius,<br /><br />The IS-3 tests show penetrations using the 122 mm gun, both BR-471 and BR-471B rounds, when there *should be no penetrations at all* even at *point-blank range*, by the Bird/Livingston data and even more so with your data. Even when you throw in overmatching, it doesn't explain the results.<br /><br />That makes all your ballistics data irrelevant; it doesn't matter what velocity the gun/round has if--whatever it is--it penetrates. You can quibble that saying that the round really has 781 m/s instead of 800 m/s, but it's really irrelevant. You can argue that a penetration at 900 meters really only means it should only happen at 500 meters or less, but that's still inconsequential to this discussion. The Bird and Livingston values say *no penetration, even at point-blank range" and you want to make that disconnect with reality even greater, instead instead of correcting it to reality.<br /><br />And no, here it can't be bad armor because the same armor that is yielding to the 122 mm is also bouncing both the standard Kwk43 APCBC rounds and Kwk42 APCR rounds.<br /><br />Before I rant on: Peter--I think I've asked this question before-it's not clear to me that in these tests whether or not the 80 % or the 20 % penetration criteria is being used. There are terms like "can be penetrated", "is reliably penetrated", "crew is completely protected", etc. in the descriptions and I'm trying to read between the lines. My own inclination is that Soviet testing is conservative; when they are testing their own weaponry against possible use by enemy weapons; they use the 80 % penetration criteria; but they often use the 20 % criteria when evaluating their own armor's vulnerability to enemy weaponry. <br /><br />Like the IS-2 Model 1944 should be impenetrable to the Kwk43 even at point-blank range using Western criteria for penetration and slope modifiers, even for a cast hull (and both welded plate and cast hulls were used, I recall) but your article says the limit is 600 m: <br /><br />"Frontal plates *fully protect* the crew against fire from 88mm German armor-piercing shells from 100 meters under any angle, while the upper frontal plate of IS-2 protects only on distances of 600m and higher"<br /><br />That 'fully protects' makes me wonder if the 20 % criteria is the one being used.Stewart Millenhttps://www.blogger.com/profile/01261690405884935161noreply@blogger.comtag:blogger.com,1999:blog-5030145265861917845.post-33081667298136685372019-05-17T13:20:41.596-04:002019-05-17T13:20:41.596-04:00So you are now disputing the ranges of the IS-3 te...<i>So you are now disputing the ranges of the IS-3 testing I linked too as well?</i><br />Of course. Until they corrected the firing table data all stated range to when something penetrates is subject to doubt.<br />I don't know what formula the Germans used but if you use the Soviet's own DeMarre formula with K=2400 the 122mm does not penetrate at any range.<br /><br />Killakiwi, had the best approximation but that is with the D-25/A-19 gun with a MV=795/800 m/s. The D-25T of the JS-2 had a MV=781 m/s so the range would be a little less.<br /><br />As for the SU-152 I don't know if they had APHE by the time of Kursk or only had HE and anti-concrete shells. At Ponyri there was a case of a Ferdinand penetrated in the side from 800 meters by a SU-152. Mobiushttps://www.blogger.com/profile/05256982406940327658noreply@blogger.comtag:blogger.com,1999:blog-5030145265861917845.post-46878886272540676272019-05-17T12:37:28.425-04:002019-05-17T12:37:28.425-04:00@Mobius
So you are now disputing the ranges of th...@Mobius<br /><br />So you are now disputing the ranges of the IS-3 testing I linked too as well?<br /><br />Not only that, even if you allowed for the ranges being incorrect (which I continue dispute) the 122 mm is still outperforming what you contend it could do by those tests. That by itself not give you pause? <br /><br />The reality is what happens on the battlefield, not figures on your sheet of paper. As I said, there are reports from battles like I cited, plus providing fire support from a 1.5-2 km range was the recommended procedure for both IS-2 tanks and ISUs. The Soviets would not be recommending this if the 122 mm gun a) lacked sufficient accuracy to hit anything at that range, or b) lacked sufficient punch for the job. <br /><br />The ISU-122 in particular was used in the 'ambushing the ambusher' role--by sitting back at long range overseeing a Soviet advance, and taking out any German heavies popping out from cover to ambush the advancing first-line Soviet tanks and infantry. This tactic would not have worked if either the 122 mm missed most of the time at that range, or the round usually simply shattered or bounced its target at that range. In such cases, the German "ambusher" would have soon ducked back into cover; for this tactic to work the round has to have a high chance of both hitting and also disabling or destroying its target. <br /><br />One of the jobs of any historian is to reconcile apparently contradictory evidence. You are discrediting every piece of evidence contrary to yours save what's written on sheets of paper. I am not disputing your evidence per se, no more than I dispute, say, Soviet IS-2 reports of their rounds also bouncing at relatively short ranges (600-700 m) off the Panther's upper hull--as I said, the WW2 weapons site also shows that the uncapped BR-471 round has a significant shattering chance there, which led to the BR-471B round development, and there obviously QC problems with all German armor. I think a combination of these explains that. <br /><br />As for the October 1944 WaPruf values, these are calculated values, not actual test results. I have replicated some of those calculations myself, and they show no penetration by the 122 mm against the Panther's upper hull at 30 degrees simply because they don't take overmatching into consideration--just like they also mistakenly have a T-34/85's hull bouncing a Kwk42 round past 300 meters and suggest that the turret of the T-34/85 is by far weaker than its hull (when a survey of knocked out T-34s (posted here by Peter) showed quite the opposite--more kills by hits on the hull than turret). <br /><br />In short, I try to explain and reconcile any contrary evidence, not just deny it. As for your ballistics data, the IS-3 test results comparing the 122 mm and the Kwk43 that Peter posted and I referenced should cause you to take pause. I say that because even using the Bird and Livingston data which you so disagree with, the 122 mm **should not be penetrating the armor in some of these tests at ANY range**, PERIOD, let alone with the reduced ballistics. But the holes are three. Here we're talking about good-quality Soviet armor, not dubious-quality German armor. <br /><br />Maybe that should raise the possibility that just perhaps there's something about the 122 mm gun and round that is not modeled well by the Demarre or other calculations? That, for some reason, it overperforms the calculated values? These equations can produce known deviations from observed data.Stewart Millenhttps://www.blogger.com/profile/01261690405884935161noreply@blogger.comtag:blogger.com,1999:blog-5030145265861917845.post-31302645220054130392019-05-17T09:35:47.515-04:002019-05-17T09:35:47.515-04:00Here's the deal:
The 122mm can take out a Pant...Here's the deal:<br />The 122mm can take out a Panther for sure at 1.5km.<br />The turret, lower plate and sides are extremely vulnerable against an 122mm AP shell even at long range.<br />And I don't doubt that at one point the shell was able to penetrate a Panthers front armot at 1.5km due to decline in German armor quality.<br />However against good quality Panther armor I doubt this would be the case.<br />Lets look at another shell as example:<br />https://apps.dtic.mil/dtic/tr/fulltext/u2/301343.pdf<br />The 120mm T116 APBC shell weighs roughly 22.13kg without windshield and penetrates 101.2mm of armor at 55° with ~766m/s under army criteria, meaning that it counts as complete penetration as long as light shines through a crack made.<br />Against an 80mm plate the velociy required would be around 681m/s from the differences in thickness and energy required. Overmatching of the plate might lower the velocity but since it's army criteria lets assume 681m/s is enough to completely penetrate the armor.<br />The 122mm AP weighs 25kg so it puts around 9.2% more mass against the same area, lowering the velocity to 651m/s.<br />From the ballistics of the shell this would mean that it can penetrate 80mm at 55° at around 1140m. Which also matches with my calculator if I give the Soviet shell the same quality as the US shell which should be alright since shell quality is generally more important against flat armor when the shell pierces the plate.<br /><br />So even under favourable conditions I don't see the 122mm AP shell penetrating the Panthers armor at more than 1.2km, unless the armor was, due to brittleness, more susceptible.<br />Something that would also allow the 122mm to outperform the 100mm when it comes to penetrating the Panther at longer range.KillaKiwihttps://www.blogger.com/profile/04760488116137443661noreply@blogger.comtag:blogger.com,1999:blog-5030145265861917845.post-74276217102463692952019-05-16T18:35:02.903-04:002019-05-16T18:35:02.903-04:00@Stewart Millen
You continuously provide data of s...@Stewart Millen<br />You continuously provide data of shots at incorrect ranges to prove that the ranges are correct. Do you not see the fallacy in that? Mobiushttps://www.blogger.com/profile/05256982406940327658noreply@blogger.comtag:blogger.com,1999:blog-5030145265861917845.post-13118000889123361242019-05-16T17:40:49.168-04:002019-05-16T17:40:49.168-04:00So unless you have photos of the Panthers 'tha...<i> So unless you have photos of the Panthers 'that approached Gerasimov' with 122mm holes in their front hulls my comments stand. </i><br /><br />Then you'd just claim that the penetrating round wasn't fired from 1500 meters, in the absence of any certification of range. You know as I do that most actions aren't accompanied by photographers and even if there were any present, the photographs may not have survived or have been published. <br /><br />But I can give you this, one of Peter's post. A test done at close range, but against a target far tougher than a Panther-- the IS-3, and comparing the D-25 versus not the Panther's Kwk42, but against the even better Kwk43.<br /><br />http://tankarchives.blogspot.com/2015/04/common-questions-kwk-43-vs-d-25t.html<br /><br />http://tankarchives.blogspot.com/2013/10/is-penetration-tests.html<br /><br />So if the D-25 can beat the Kwk43 in at least some actual tests at specified, known, ranges, why do you have this problem saying it was also maybe a better gun a weaker gun when fired at weaker armor?<br /><br />Stewart Millenhttps://www.blogger.com/profile/01261690405884935161noreply@blogger.comtag:blogger.com,1999:blog-5030145265861917845.post-35175131640192732552019-05-16T17:38:50.488-04:002019-05-16T17:38:50.488-04:00And if some Panthers were destroyed from 1.5 km fr...<i> And if some Panthers were destroyed from 1.5 km from some hidden JS-2s it doesn't follow they were struck on their front hulls. </i><br /><br />There were 30 (!!) Panthers. There were only 10 IS-2 tanks. One of the flaws of the 122 mm D-25 that was reported by its crews was that it produced a lot of smoke when fired, giving away its position--so those IS-2s wouldn't stay hidden very long. <br /><br />And you keep telling us that the D-25 not only lacks sufficient punch, it lacks accuracy too! So according to you, a lot of that first salvo from the IS-2s fired from 1500 m would have missed the Panthers, giving them ample time to turn their hulls to face the IS-2s. <br /><br />Now, with a 3:1 advantage in numbers, and each Panther being able to push out 6-8 rounds per tank per minute, while the IS-2s (and these are undoubtedly early-model IS-2s, with the inferior "gumdrop" sight and the slowerer reloading time) can maybe crank out 2 rounds a minute. So even if only 20 Panthers returned fire, that's 120 rounds of Kwk42 ammunition you describe as highly accurate and potent flying towards the IS-2s while only maybe 20 rounds of D-25 rounds during the same time frame, rounds that you describe as being both inaccurate and lacking sufficient punch, are returned.<br /><br />(Now, I am not saying that in actual tank fights crews push out the maximum # of rounds, any more than they push the tank to its maximum speed always, just that the ratio of exchange over an equivalent time would be about 6:1 in favor of the Panthers, assuming that both sides have equivalent delays. But then again, if you're in a Panther and you've already acquired an IS-2 and are hitting it, why *not* pump into it shots as fast as you can?? Why would you want to re-aim?). <br /><br />Yet, when the smoke literally clears, the German Panther unit has lost 2/3rds of its tanks, 20 tanks in all with 15 irrecoverable losses, while only 2 IS-2s were lost (1 irrecoverable). Usually, the simplest answer is the best, and the simplest explanation of what happened during that engagement is that, at the range of 1500 meters, that:<br /><br />a) It's probably true that given the Panther's great advantage in rate of fire, the fact that the Panthers had great numerical superiority, and the fact it had an accurate gun, probably a fair number of Kwk rounds did in fact hit those the IS-2s. But the vast majority of those rounds, at 1500 meters, was just 'plinking' the IS-2s to no effect. Eventually with enough hits you either hit a weak spot (say, the IS-2's lower hull, or a spot thereof not covered by spare tracks) or you luck out and hit the 100 mm frontal cheek armor or 110 mm mantlet at a low-probability, near-normal angle of incidence.<br /><br />b) When the D-25 round hits a Panther, no matter where the round lands, it equals 'game over'. The Panther is either put out of commission if not totally. As one Soviet tanker said "with the IS-2's 122, one hit was usually all that was required". That's why the Soviets kept it on the all their postwar heavy tanks until they put an improved version on the T-10. Why would you think the Soviets would have stayed with the D25 unless they too thought it was a perfectly good gun.<br /><br />Stewart Millenhttps://www.blogger.com/profile/01261690405884935161noreply@blogger.comtag:blogger.com,1999:blog-5030145265861917845.post-90800763519979255452019-05-16T17:37:34.998-04:002019-05-16T17:37:34.998-04:00@Mobius,
We were talking about the A-19's per...@Mobius,<br /><br />We were talking about the A-19's performance and you want to shift gears to the ML-20? As for the ML-20 on the SU-152, Wikipedia:<br /><br />"<b>Although designed with no consideration for the anti-tank role </b>, the SU-152 proved to have surprisingly good anti-tank capabilities due to the ML-20S's extremely heavy HE projectiles. Standard doctrine for purpose-built AT guns of the period universally relied on small, dense solid projectiles propelled to high velocities, optimized for punching through armor. Since the SU-152, like all SU-series self-propelled guns <b> was not designed with tank killing in mind, no AP projectiles were issued to crews and no initial tests against armor were conducted" </b><br /><br />The use of the SU-152 and the 152 mm gun as anti-tank guns was an improvisation. Ditto with the A-19 at Kursk. I had recalled that the SU-152 crews weren't even issued AT rounds initially so they fought without them at Kursk; even after they became available, it was maybe just one AT round per vehicle because the large HE round was just about as effective.<br /><br />The IS-2, for its part, typically carried no more than 9 BR-471 or BR-471B rounds per tank, with the rest HE, because that was considered plenty.<br />Stewart Millenhttps://www.blogger.com/profile/01261690405884935161noreply@blogger.comtag:blogger.com,1999:blog-5030145265861917845.post-76543540383078794522019-05-16T16:31:05.418-04:002019-05-16T16:31:05.418-04:00@ Stewart Millen,
I'm sorry that you haven...@ Stewart Millen, <br />I'm sorry that you haven't read that I pointed out the Russians tested the 152mm AP-T shell in May 1943, before Kursk. (I am not including the 122mm HEAT shell in this discussion.) So saying that the Russians didn't know of its armor penetrating ability is a false statement. <br /><br />And if some Panthers were destroyed from 1.5 km from some hidden JS-2s it doesn't follow they were struck on their front hulls. As you probably know that when one side suffers high losses while the other very few it is often from ambush from the side or rear. So unless you have photos of the Panthers 'that approached Gerasimov' with 122mm holes in their front hulls my comments stand. <br /><br />Don't get your hopes up of being a 1400 meter penetration. That was thought to happen when struck at 718 m/s. Because of the firing table range error it works out to only about 600 meters.Mobiushttps://www.blogger.com/profile/05256982406940327658noreply@blogger.comtag:blogger.com,1999:blog-5030145265861917845.post-20928816707909615712019-05-16T13:36:10.867-04:002019-05-16T13:36:10.867-04:00Yes, a couple of Panthers were shot up. They are l...Yes, a couple of Panthers were shot up. They are listed in this article, 525 is actually 535, but the bottom part of the number is destroyed.Peterhttps://www.blogger.com/profile/09622237223229485503noreply@blogger.comtag:blogger.com,1999:blog-5030145265861917845.post-30237674804227312522019-05-16T13:02:10.371-04:002019-05-16T13:02:10.371-04:00We were discussing the anti-tank performance of th...We were discussing the anti-tank performance of the A-19/D25 122 mm gun, and you bring up an article describing the testing of a HEAT round developed for the ML-30 122 mm howitzer (in the SU-122 as well as in artillery units) and the ML-20 152 mm howitzer (that went into the SU-152 ans well as artillery units). This is not relevant a discussion of the anti-tank performance of the A-19/D25 and moreover even with the ML-20 and ML-30 guns the HEAT ammo was in short supply and most of the time the HE round was used, which worked well enough. Nor is the fact that HEAT rounds were developed particularly telling, as most everyone developed HEAT rounds for their artillery pieces just in case they encountered enemy armor; it doesn't mean that they were being seriously considered in an anti-tank role. The SU-152 and the SU-122 were developed with infantry support in mind; it was from necessity at Kursk that they showed they could also take out enemy armor.<br /><br />As for a HEAT round for the D-25, the there was one developed that could be retroactively fit into it, in 1961. That's all I know about that.<br /><br />You were disputing my contention that it was battle of Kursk that alerted the Red Army to the potential of the A-19/D-25 as an antitank weapon, and my followup post I think I demonstrated that indeed, if was the combat performance of the A-19 against actual German heavy armor (Tigers and Panthers) that alerted Red Army designers to its potential in the IS tanks, and the actual testing was done later was to confirm and quantify the results already observed in combat. The A-19 was an effective wrecker of German tanks by battle, and this was demonstrated in actual combat at Kursk, not by testing or calculations--and you had questioned whether or not there was any evidence from actual battles that it was. I gave you examples both from Kursk and from an actual battle involving Panthers versus IS-2, at 1500 meters, with the Panthers even enjoying a 3:1 numerical advantage against the IS-2s yet the Panther unit got shot to pieces by the IS-2s, at a range that you seem to deny was even possible to get penetrations, at a minimal loss to the IS-2s. To me, you're arguing against an established fact.<br /><br />As for the 'the 122mm test hit the side' comment, if you look a the photo provided in this very post, there is a penetration shown; and the caption says of the Panther's front armor:<br /><br />https://4.bp.blogspot.com/-WoNx55sGAGE/XM-vKta-uyI/AAAAAAAAbHQ/5-y6DVdual40QAz-NzWNuEWONemBKgyuwCLcBGAs/s640/pantherdussr20-6e2b0d67192351aa8711245d54abed37.jpg<br /><br />The test results here show the side penetrations:<br /><br />http://tankarchives.blogspot.com/2013/03/is-2-vs-german-big-cats.html<br /><br />But there are some questions here. One the penetration shown in this post appears different than the two penetrations shown in the second, and different Panthers appear to have been used. There is a tank '525' and a tank '445', and in the '525' (?..can't tell for sure) it's the rear turret plate, not the side armor plate, that has been torn off and is lying on the ground (plus the turret is turned differently). So the frontal 1400 meter penetration may be on tank '445' and the side penetrations may be on tank '525'.<br /><br />Peter, do know more about this in the documentation you have?<br />Stewart Millenhttps://www.blogger.com/profile/01261690405884935161noreply@blogger.comtag:blogger.com,1999:blog-5030145265861917845.post-50662499426675540452019-05-15T19:21:00.845-04:002019-05-15T19:21:00.845-04:00@Steward Millen
I responded to this bit on the AP ...@Steward Millen<br />I responded to this bit on the AP shell of the 152mm :<br /><i>Battle of Kursk, the Soviets leveled their 122 mm and 152 mm guns at German heavy armor, because their 76.2 guns were found lacking, and found how "whoa!! these things do an awesome job</i><br />Where you conflated the discovery of the anti-tank ability of the A-19 with the ML-20.<br /><br />Plus, the 122mm test hit the side turret of the Panther, not front hull.<br />Mobiushttps://www.blogger.com/profile/05256982406940327658noreply@blogger.comtag:blogger.com,1999:blog-5030145265861917845.post-10430830471903727452019-05-15T17:04:42.468-04:002019-05-15T17:04:42.468-04:00@Mobius
You're referencing an article on usin...@Mobius<br /><br />You're referencing an article on using HEAT rounds on 122 mm 1938 *howitzers* (not the 122 mm A-19 corps gun) as a rebuttal? Did the article on the usage of 122 artillery 152 artillery pieces mention HEAT round usage Kursk? (Seem to me they were either AP rounds or HE that wreaked all that havoc). <br /><br />For that matter, did the IS-2 carry any HEAT ammo? (It did not, to my knowledge).<br /><br />Sigh..<br /><br />http://english.battlefield.ru/en/tank-development/26-light-tanks/19-christie.html<br /><br />"The first person to suggest arming the JS tank with a gun larger than 85 mm was the Director and Chief Designer of Factory No.100, Zh.Y.Kotin. He realized in <b> August 1943, after studying the results of the Kursk battle, that the most effective anti-tank weapon employed against German Tigers was the Corps 122mm Field Cannon A-19 Model 1931. </b><br /><br />The designers at Factory No.9 came to the same conclusions as Mr. Kotin, and designed the D-2 Heavy Anti-Tank Cannon by marrying the A-19 barrel with the carriage of the Divisional 122mm Howitzer M-30.<br /><br />This powerful weapon was ordinarily employed against heavy tanks as an anti tank gun. The barrel of the gun was built into the gun carriage of the M-30 and the resulting gun successfully passed its tests, it became possible to install the A-19 gun in a heavy tank by using recoil-absorbers, elevation mechanism, and other mechanisms from the Experimental 122 mm Tank Howitzer U-11. This was done in a similar fashion to the 85mm guns D-5T and D-5S, but it was also necessary to add a muzzle brake.<br /><br />{..}<br /><br />The first example of the A-19 tank gun was ready on <b> November 12, 1943 </b>- the barrel of the D-2 gun was removed from the M-30 gun carriage and installed in the D-5T base after after reducing its diameter. The T-shaped muzzle brake design was borrowed from the D-2 gun. The unusual muzzle brake was intended to reduce the main disadvantage of any muzzle brake: when a shot is fired, a large cloud of dust is kicked up from the ground, revealing the position of the tank. The T-shaped muzzle brake was intended to minimise any dust plumes due to firing.<br /><br />The JS-122 (Object No.240) passed the Government tests quickly and successfully. Thereafter, the tank was moved to one of the Moscow military testing grounds where it was demonstrated to K.E.Voroshilov. The tank's 122 mm gun was fired from 1500 metres at a captured German Panther tank.<br /><br />The round hit the side of the Panther's turret, penetrating it cleanly and tearing the opposite side out at the welded seams, throwing it back a few metres. During these tests the muzzle brake of the A-19 blew up almost killing Voroshilov. After this accident it was decided to change the muzzle brake to a 2-chamber design similar to that used by the Germans."<br /><br />I recall that these tests were actually performed at range, not with reduced charges. Also, as you can see, the tests were done after November 12th, 1943. IS-2 production was ready in December.<br />Stewart Millenhttps://www.blogger.com/profile/01261690405884935161noreply@blogger.comtag:blogger.com,1999:blog-5030145265861917845.post-66043441687050854942019-05-15T15:15:59.055-04:002019-05-15T15:15:59.055-04:00@Stewart Millen
I got your mother-of-invention ri...@Stewart Millen<br /><br />I got your mother-of-invention right here. <br />http://tankarchives.blogspot.com/2016/08/high-caliber.html<br /><br />There was no 'discovery' of anti-armor ability of the 122mm and 152mm M 1937 at Kursk unless you believe July 1943 comes before May 1943. Because those guns were tested in early May 1943.<br />Mobiushttps://www.blogger.com/profile/05256982406940327658noreply@blogger.comtag:blogger.com,1999:blog-5030145265861917845.post-83096263868474359372019-05-15T14:12:24.353-04:002019-05-15T14:12:24.353-04:00The effectiveness of the A-19 against Tigers was s...The effectiveness of the A-19 against Tigers was shown in the same trials where the ML-20 missed completely, so it was firing from a real distance. Shot #1 passed through a previously made breach in the front and punched through the rear armour, shot #2 hit the turret with such force that it was displaced from the turret ring, shot #3 ricocheted off the roof but the impact caused severe cracking. <br /><br />As a result of these trials, the GABTU requested a tank destroyer made up of the SU-152 chassis and A-19 gun. The IS-2 was only produced a couple of months later.Peterhttps://www.blogger.com/profile/09622237223229485503noreply@blogger.com