Scav

So I should assume a higher protection under the EMES-15. Ha, lol. I should've checked it, the layout seemed odd for a book... Well, to be fair, they did give their sources and as far as I can tell what they claim about the 2A4 is more or less correct. At least Frank Lobitz says the same things (one of their sources actually). I agree, it's a big mish mash and you're never quite sure what they mean. Especially the "generations" are odd because they might even assume there was an older generation than B tech for all we know. Well, the way I see it there's two options: either he had good info regarding the upgrades carried out (he mentions base armour being upgraded in the 1988 model which AFAIK is confirmed) or he didn't have good info and guessed based upon other authors and pictures, in which case he might not have known that the 1991 models had improved internal armour too. But considering he specifies that the internal armour was upgraded in the 1988 model while saying only the skirts were upgraded for the 1991 model, I would think he does actually have decent info. I think he's trying to say this: So it seems he's putting emphasis on "now also", which to me makes it seem like he's pointing it out as the sole difference. That said, German isn't my native language (and I'm a bit rusty) nor do I have that book to properly judge the context. Well, it could very well be a more optimised skirt than previous models which was ready before the rest of "D tech", so ready for early adoption. I recall seeing a picture of a leopard 2 skirt somewhere with "holes" under the surface, not sure if that was the early variant or a later one. I doubt those skirts can offer more protection than the frontal armour even if it's at, let's say, a 15° angle. From pictures and what @Militarysta posted on his leo 2A4 armour measuring page, it seems to me that the early skirts weren't that heavy or dense, probably consisting of spaced plates that aren't very thick. At the same time, they also started using C tech midway through a batch, that seems like a bigger change than some different skirts. Hence I don't think changing skirts was a major thing or would be "held back" to coincide with an internal armour change. Interesting.... possibly a typo or maybe even a contradiction to what he earlier said? Could very well be a small difference. Mounting points being different could indicate a new skirt possibly being heavier or lighter.... or it could possibly be an optimisation from field testing showing different mounting points were desirable.

That would refer to C tech as far as I know. Still, good info, don't find much of that.

It's British, they'll just use teabags as side armour.

Thanks! So I assume he doens't talk about wether or not the base armour was changed in type? This was the information I was looking for, thanks!

@SH_MM I've recently found this book again: https://www.yumpu.com/de/document/view/10795487/leopard-2-gfj-hostingde It also talks about the leopard 2A4 and the different technologies: It's saying one of the improvements was new skirts, both light and heavy in D-tech. Which IMO makes sense given there's leopard 2A5s with both these and C tech ones. There's some minor issues with this book, namely they seem to have taken some internet estimates for the armour.... Anyway, would you mind sharing what Rolf Hilmes or other authors have to say about this? Could you maybe show a small snippet of the books you use?

True, the biggest downside of that design arguably.

Hm, Abrams seems to have quite a thin mantlet in comparison with the rest of the turret though, Merkava is definitely also one that has good protection around the gun, but the T-series really does have a weaker area around the gun than the rest of the turret, even on the T-90A it's only protected by normal steel blocks, Challenger 2 did seem to have an OK mantlet but it's still thinner than the rest of the turret front, so unless there's some armour block or spallshield behind that I would still consider it weaker than the rest of the turret.

Small size from the front, yes, from the side it's not that small. Mantlet on some tanks is weak, but others like the 2A5 isn't, though that's mostly an exception to the rule.

Different design philosophy, can't directly compare the "efficiency" of the armour layout to each other since one has an unmanned turret that is likely paper to any calibre of 90mm or higher while the other has the heaviest armour on the front of the turret. So, while the abrams has to cover a lot of space, it also does a good job of that, unlike the T-14 which relies entirely on not getting hit in the turret by any decent KE or HEAT shell. You might argue that the crew will live because they're not in the turret, but you don't know that, if their capability to fight back has been neutralised that means anything can then follow up, even IFVs, which will absolutely wreck any optics making the crew blind so they have to rely entirely on poor vision or GPS to find their way back to cover. Even if the tank does get out of the situation with "only" a firepower kill, that's still a neutralised tank, if that was an M1A2, it could've taken the hit and potentially fired back. Sure, the T-14 probably is more weight optimised, but you're also comparing a late 70s tank to a mid 2000s tank while not taking into account the consequences or results of that higher weight optimisation.

Fixed that for you.

In general there seems to be information that I'm not able to find readily on the web, I'm really looking for small details and mechanics and such. Yeah, it's not easy to see the thickness of either without having a measuring tape. It was just a rough guess. Yeah, I expected some minor changes in the hull and I didn't know C tech was weight neutral. So more or less a complete overhaul of the armour? I agree, that's why I initally thought D tech wasn't a main armour technology but small things like skirts and add-ons. While the LOS is higher, that's mostly because of the empty space between the two blocks of armour, that might help or it might not,, logically it would atleast provide more space that the penetrator has to deal with, but if the armour packs itself are only like 650mm or so (looking at Laviduce's model) and the space in-between makes up the rest.... I don't think it would actually provide more protection than the rest, or atleast not significantly more. Considering the turret cheeks are roughly 20% of the frontal area of the tank and that correlates to around 400mm if we look at that protection graph. Now only around 6-7% of the surface area is protected against 500mm but that % stays more or less the same all the while it goes up to 700mm, so I don't think it's actually talking about that section under the EMES-15 but rather some other overlaps or places around the mantlet for instance where you have a lot of steel, or even the area just above the UFP on the roof where there's still special armour right under it. If the area under the EMES-15 would indeed provide more protection I would expect that to lead to a higher % of the tank to be protected against 400mm from the +20° angle compared to the -20° angle. Though there are some small weird anomalies like more surface area being protected of a + angle (right turret cheek, where the optic is) from 300mm and 500mm, I think that might be due to overlaps or perhaps even the added armour for the driver's side. At the same time I'm not even sure if the armour behind the optic is weaker than the normal cheek armour, they could very well have made it denser to compensate, though for simplicity reasons this might not have been done. What's your take on this? Do you think the EMES-15 area is weaker and the area under it stronger despite having "less" armour but more LOS? And, now that I think about it: wouldn't that space actually be partially filled with the traverse mechanism? That might add quite some steel which wouldn't show up on an armour analysis but would help in reality.....

Might've even been a book for all I remember, it's not that easy to find. Oh interesting, I'd imagine that they did something so the commander can more easily reach the hatch? That doesn't seem very thick no, but I think the space might still provide the necessary room for the penetrator to yaw or deform, which would massively reduce penetration. Are you talking about this picture: It's pretty hard to tell how thick it is, I think it says 26 or 28mm. Might be related. I agree. I honestly didn't even consider that one, I find pictures like that a little bit vague so I mostly focussed on the one with the actual numbers. Thanks, I really need that book it seems, there's a lot of info in there I assume. Well, from what I can tell the driver's hatch was changed and it seems like the hull roof itself might've been made thicker (I saw some picture where you could see the hatch open and compared it with a 2A4 picture, not exact science) and seen multiple people also make that claim. So most of the weight changes was turret? That would definitely indicate more changes than I thought. Just something I heard from two ex-loaders, one on a 2A4 and the other on a 2A6M, the 2A6M guy said those skirts were pretty damn heavy but the other one was surprised because he found them quite light. Would've been a minimal weight difference if any. I was under the impression that the weight was 62.5 for the 122B, sorry. Yeah I assumed the choice was between German army version and Swedish Strv 122. Makes sense, I guess they didn't bother with all the possible combinations though? To me it makes little sense to have B pakette + B add-on (whatever that is if it even exists, which I doubt) so that would reduce the amout of possible combinations. About that picture for the protection angles: I find it odd that the "German solution" doesn't give equal protection on the left turret face compared to the right turret, if it's the optic, that would be the other way around....

Yeah, not sure where I read it, but I think some British source says that the leopard 2 development was already too advanced to incorporate Burlington, I'll try to find that. I drew the same conclusion, though I don't know much about the TVMs. Quite likely, it also seems like the armour they wanted for the Strv 122 was a slightly later development and thus they had to make it themselves during or before the testing. Could be, but to me it seems like it adds quite a bit of weight (probably less than a tonne though) and extra profile, maybe it's not needed, maybe it is, I don't know. Doesn't the commander actually sit higher though? At the very least it increases the profile so more of the tank is visible if you're in a hull down position, not sure if that's a bad thing for thermal optics but it definitely looks like a bigger target or easier to identify. The Swedes considered it inert, but as far as I can tell it's still part of the crew comparment (atleast for the hatches). In any case, they've done similar things in the past (German M48, lowered cupola), probably with a good reason, perhaps in hindsight the saying: "'Better safe than sorry" is applicable. Yes, but I think for the PzH 2000 it's necessary to armour it against counter battery fire. For the Puma it's also necessary because of it's role as close infantry support. It might also be necessary for the MBTs, IDK. Hm, I should rephrase that: I think the purpose of the wedges was to roughly retain LOS efficiency (and thus massively increase protection) but as an overall package and not purely because of the wedge if that makes any more sense. While they are mostly empty, they are made of more modern materials and constructed in a different manner, I wasn't trying to argue based purely on LOS effectiveness but that the wedges are cheap, light and maintain the overall efficiency of the entire armour array, they could go with denser and higher efficiency armour but that seems more expensive and more trouble than it's worth. In that case I don't think upgrading the base armour from B to something else would be necessary to attain the 800-850mm effectiveness with the wedges, as they are made of more modern materials and do a seperate job that doesn't just "add" to the base armour but compliments it. So despite them being way more air and less dense than the base armour, they can still provide the necessary protection in combination with the main armour to essentially double the effective armour because they are made of more modern materials. I think they might honestly have been lazy enough not to "grey out" those boxes, another reason why I suspected "D-tech" wasn't a main armour tech despite being shown as a possibility, could also be because they had extra "blocks" similar to those fitted to the Pz 87 140 as add-on instead of wedges. Possibly they found out that having the add-ons slightly further and at more of an angle compared to the main armour increased effectiveness despite being thinner? They might also provide the same protection but with less weight like you say. Same data, different conclusions or theories :). I think this could very well come from a difference in add-on modules, base armour is also possible, I have to point out that the 720mm figure is pointed right at the mantlet/breech area and not the plain cheeks like the others. In this case I very much think different angles cannot be compared directly or "converted" to attain different figures. The wedges are quite complex, they have two layers and because the angles differ I wouldn't call this traditional NERA but more like you said: "comparable to heavy ERA", I would go even a step further and outright claim that "converting" or calculating different angles is simply impossible. Interesting, he didn't mean it as an overlapping statement? Haven't found a place where I can get that book yet, I've wanted it for quite some time now. Don't forget the mantlet, turret drives (probably lighter) and some other internal changes though, while the Dutch did reveal the weight I wonder if they didn't round it off or kept it at 500kg just to be vague. AFAIK the Strv 122 also incorporates the mine protection, which is probably around 1-2t. If we compare normal 2A5 to 2A4 it's 59.7t and 55.15t, around 1.5-2t is for the turret which leaves 3-2.5t unexplained: front hull roof was increased, armour of turret roof and so was driver's hatch (not sure how much, could be little to nothing), new heavier skirts, spall liners were fitted and the armour infront of the optic was increased. I agree that falls short of the weight difference, I don't know how much though. IIRC it had C3I, roof protection and hull protection that was all superior to the german 2A5, that could be all or there might be more. Good point, I don't know, perhaps this was for an earlier version, though that doesn't seem likely. On the 2A4 where B was indicated it didn't mention a combination, do you think the combination number refers to the order of the selected modules? As is often said: "You have a no, but you can get a yes". I don't have high hopes though. Well, I'd hoped to get more answers but it seems you've left me with even more questions ... I think I'll make some armour estimates for the different graphs in the leopard 2 thread with this new info. Thanks for the input!

Yeah, I discussed this at length with one of my friends, we basically came to the conclusion B tech was probably something like spaced steel (with relatively thick plates) array either with rubber liners or suspended in rubber so it can move. I don't think they used something like Burlington or BRL-1 simply because when the UK shared the info they also commented that Germany already had different composites and was chosing those for the leopard 2AV, still it's a possibility though I think it's less likely than the spaced array option. Fair point. Hm, well as far as I can tell the Leopard 2 "improved" that was tested by Sweden and sent from Germany had the B pakette + D-2 wedges (as seen on that graph comparing leopard 2A4 variants), at least he values seem to match the ones tested by Sweden. I agree, it seems they accepted the Strv 122 add-ons instead of the other ones, at least the turret front, side, hull side add-ons were accepted on the 2A5. Hull add-on was definitely for cost saving reasons, roof seems to be a deliberate choice as the Germans don't seem to like the roof add-on and how much it increases the profile (atleast two German crewmen told me this was a general consensus among crews). To me it seems like the Swedish version(prototype) still used atleast B tech turret, just with different wedges and perhaps the hull too, the wedges add something like 700-800mm LOS to the front turret while also almost doubling the effectiveness, so it stays around 0.5 LOS efficiency which doesn't seem like they used anything other than base B armour, I would expect higher values if some other base armour was used. Those wedges seem pretty much an ideal solution for KE threats considering the massive LOS and rather simple nature, I think the effectiveness of them would increase almost exponentially with increasing base armour effectiveness. Basically: I think it's quite likely the 800-850mm number was "only" B pakette + the new wedges (would be cheaper than also using even more expensive base armour). Mostly just speculation but I'm basing it off the German prototype sent to Sweden already reaching 700-820mm on the turret face and those values lining up quite nicely with the chart they also provided. Exactly what I was getting confused about, my theory is that D-1 could refer to a different add-on such as the roof and thus would be pointless to represent for a frontal attack and it's also the main reason for my suspicion of a 2A4 with "D" tech armour. D-3 could very well be the add-ons used by the Strv 122 proto. I don't know frankly and I've been debating this with friends for quite some time, it's also why I very much appreciate the continued discussion :D. I think the green graph represents the Strv 122 prototype considering only about 30% is below 700mm protection (LFP is roughly 20% of the frontal profile and turret roof 9%, both of these I doubt you can armour past 700mm without adding too much extra weight) so that's either B pakette + D-3 add-ons, assuming D-3 is better than D-2. Blue could represent B pakette + D-1 + D-2 or C pakette + D-1/D-2, but I don't know and I doubt we'll know without asking someone involved with the trials (perhaps Lindström can be contacted?). I agree with red probably representing C and pink representing B, yellow we also have a good candidate for but the rest is pure conjecture honestly. Still fun to talk about though. Possible as well. Yeah, sorry, that is the most likely option which is why I find it suspicous to be missing from the graph. In that case I agree, probably wasn't an add-on. ohhhh, thanks! I always wondered why it looked relatively modern (clean) without some kind of restoration having been done to it. It certainly doesn't help there's a couple of people that always make crazy claims for the M1 series (and most "normal" people believe these guys). I always thought it would be atleast about leo 2 level but didn't know for sure, so when one of my friends said he was working on a restoration in this museum I jumped on the chance to ask him :). I still want some better pics as it would definitely help to combine both inside measurements to outside measurements. True, side effect (probably intended) of their simulation I guess. Yep, that's one advantage of such a spacious and wide armour design I guess. If you compare the leclerc, leo 2 and M1A2 you can still see just how small the actual crew area is on the leo 2, it's even smaller than on the leclerc! Thanks! I have been looking on that site but clearly my search skillz weren't quite up to par .

Well, apparently they're going to go with BAE and if they do that, that means any future procurement will also be given to BAE. Rheinmetall's upgrade wasn't just a gun either, it was quite a bit more but I guess we'll see when they finally decide.

I know he's been "involved" with some of the projects, but he's still human and can make mistakes. But if he's right that means that the armour is better than in the Swedish tests...

Hm, so instead of continuing to use "B" tech, they replaced it with a better armour solution that gives even more protection for the base armour alone and adding wedges ontop of that? Seems quite expensive to me, maybe the author mixed up "integrated" and "add-on", but then again, they might as well replace all the armour if they're going to refurbish and rework those turrets anyway... So, they went from 350mm (30° offset) to 420mm while not adding any weight, that would require replacing a lot of the plates and not adding anything more, friend of mine suggests that perhaps they moved the array back a bit (while making it denser) and left a larger airgap behind the coverplate, combined with ceramics in the mix that would make it possible. I'm still quite skeptical of a 2A4 with D tech, it seems like an awful lot of effort for only 75 tanks. True, but they were already in the process of developing the wedges and even had them by 1991, personally I don't see the point as even D tech would be quite expensive because of the materials. Anyhow, I'll consider it a possibility. From what I recall and what I think seems to be the case is that the TVM delivered to Sweden for the trials had B pakette and D-2 add-on, the Swedes also mention they made another package based on IBDs design which was superior, from what I can tell the base armour didn't differ but the add-on did. TVM seems to have flatter add-ons and what ended up as the Strv had more tapered add-ons. So the question is wether or not they had different internal armour on the actual Strv 122 as opposed to the prototype or if the prototype already had that and what the actual combination on both is. I'll just put down what I know and suspect: German prototypes sent to Sweden: B pakette + D-2 add-on Swedish prototype in trials: B pakette + D-3 add-on? German 2A5: C/D hulls, only "D" side add-on, B turrets with swapped out inserts to D tech, D-3 wedges as add-on? Swedish Strv 122: B pakette + D-3 add-on maybe changed B turrets to D inserts? Now, we know the protection for what the Swedes had, though we don't know the exact combination they used, if they did indeed use B pakette with some D add-on that was better than the German proto, that means if the German and Swedish 2A5s use different internal armour on the turret, the protection afforded would be substantially higher? From 800-850mm to xxxx-xxxxmm? Man, this is a whole can of worms..... One thing I have to point out is how on this graph we can see that the yellow graph matches the combination B pakette + D-2 add-on: If red is supposed to represent C tech (which my estimation in the leo 2 thread was based off and which is apparently quite close to the numbers you've posted), there's no other graph that could represent a "D" pakette or base armour, as there's no way a "D" base armour is going to beat the "B" base armour + add-on. This is why I just don't see "D" technology being used for base armour, it's possible but without having read those references from those known German authors I'm hesitant, (even with references though, they could still be wrong or have mixed some stuff up, it wouldn't be the first time). That kinda leads me into the next question: can you tell me in what books they mention these things? I've been trying to find books specifically on the leopard 2 from both Krapke and Rolf Hilmes but most of them are paperbacks that are being sold in different countries or have been sold out, I also can't find any ebooks (free or paid) :/. Specifically referring to the newer books and more in-depth ones, I've got the Waffen arsenal one on the leopard 2A5 but that doesn't go that far in-depth. True, an M1A2 crewman (yeah, not the most reliable source) did tell me they changed the armour, didn't tell me they upgraded the KE protection though, he was ofcourse being quite vague. So they probably did change the armour over time, what I meant was that they didn't seem to add more armour there which could explain a weight difference, atleast not a big one. As for that picture, I agree it's a bit dubious but the possibility for replacing armour quite quickly is definitely a thing from what I can tell, so I guess it's possible that armour was changed without too much hassle (or expense). True, the tanks are quite different and the leo 2 is notably smaller in terms of volume that needs protecting so it can afford more armour for the same weight, it's just odd that a late 2A4 (wether that's C or D tech) would reach equal frontal protection, or atleast close to it, as an M1A2 while also weighing a good 5-6t less. In any case: I'm open to different possibilities if there's enough evidence, that chart coming from German sources is probably enough to prove it's not BS and talks about the armour generations/combinations. Are you talking about this "D" tech array? If so, would it be possible even plausible that it is indeed 800mm not taking into account angle because of a flat add-on ? Like on the leopard 2 with the 140mm: Yeah, those do seem likely or atleast possible. Here's one of the pictures he took from the front left corner of the armour, it's 733mm thick: However, we had more pictures and he was actually measuring it and talking to me at the same time, I'll see if I can get a hang of him because some of the pictures are on a different discord server I don't have access to. When he measured parallel to the gun (IIRC left side like on the pic) he got 78" from the front turret face to the loader's hatch and he measured on the inside 41" from the turret armour to the loader's hatch (same spot), that leaves 37" give or take a little bit which equals about 940mm. Unfortunately he didn't take pics of all the measurements as he was supposed to be working on the exhibit, but I've asked him to redo them, so I might update you on it when he gives me more pics. But yes, it does seem to be pretty much ~940mm give or take a bit. Even on that last pic you can see it go from roughly 46" to 82". Yeah, though it didn't change much in terms of protection between the Swedish M1A2 and the armour values given by the US, (Swedes got to 50% protection for 600mm KE at 20° offset, US values were 600mm across 60°? arc). Makes sense that they wouldn't cease with development, though I'm always wary of news agencies, bolt/screw changes could very well be a logistics thing, though it does suggest a change. OK, that sounds a lot more reasonable, I do know that Germany quite likes their steels or metals so I agree that they could achieve quite high thickness efficiencies. True, but they might've only changed the armour they needed, regardless I want more info . On another note: since you've pointed me into the direction for DM13 APFSDS and it's patents, would you mind telling me where that DM33 patent picture comes from?

Interesting, I think in the case of the Challenger it doesn't refer to added protection equivalent but actual LOS thickness of the entire package. As for the number of the leopard 2, B seems more or less correct, not sure about C though, it's definitely interesting that it keeps coming back that C tech had this much added over the first variants, the weight increase doesn't seem like it would be enough, perhaps they managed this by using very "light" materials such as ceramics and replacing some steel with lighter alternatives? Maybe they replaced the entire array and made it more efficient with higher hardness or something? As for Challenger 2, it seems that in the Hellenic tank trials the tank was critisised for it's poor hull protection and lack of roof protection, similar to the Leclerc in terms of protection, so ~550 wouldn't seem too far off, it's definitely worse than the M1A2 and leopard 2A5 as suggested. I still need to find the original magazine where they talk about the trials though.

Yeah, thing is, they don't specify the base armour itself being "D tech" (atleast as far as I could tell). What seems to be the case is that C tech was a base armour technology but D tech were exclusively add-ons like those in that picture you posted of the 2A4, the parts on that which I think are "D tech" are those add-ons above the ballistic skirts and the normal skirts, both of these you can also see on the 2A5 which I think is actually what they meant with the "third generation", it was after all a KWS initially and was only called 2A5 when it finally entered service. Reason why I think that is because creating another "generation" or major improvement in base armour only 3 years after the last and while also developing far superior add-ons that improve upon the base armour with rather minimal weight increases just seems wasteful and pointless. At the same time I've never seen a third "weight" for a leopard 2A4 that's higher than 56t, which is what would be necessary for an increase to beyond 600mm. Basically: if there is such a thing as "D tech" it's not going to be that different in terms of actual protection unless the weight is substantially higher, just for comparison: M1A2 "only" reaches ~620mm or so on the front turret (supposedly the US tested against their best armour protection, M1A1HA/HC, in the states and gave the Swedes that info, which would be that one page with the top down view) and weighs 62.5t while having the same hull protection as the initial M1. A friend of mine measured the distance between the start of the turret armour and the end on the M1A1 in that new US museum that recently opened to the public (the one that the Chieftain did a video on) and we figured out that the LOS thickness is ~940mm including front and backplate, so reaching 620mm out of 940mm isn't crazy, especially given teh weight of 62.5t, but for the leopard 2A4 to do the same with less LOS thickness and less weight, ontop of also increasing hull protection just seems fishy to me. That's also why I'm dubious of C tech reaching higher than 500mm on the turret cheeks with barely a 850kg weight increase from B tech to C tech, I mean, the M1A2 focussed all if the armour upgrades on the front turret and that still increased the weight at the very least 3t just going from M1A1 to M1A2. They do require extensive reworking, but it seems only the area around the gunsight, so switching out the entire armour for a new one is possible but I think quite expensive (which Germany was being careful of, unification and such...). E or F? Never seen that before, just speculation or do you have a good reason for that? Interesting.... Hang on, you're saying the entire array is only 500mm? And it stopped a rod with 600mm of penetration? So a thickness efficiency of higher than 1.0 with space gaps..... uh. Hm, wouldn't this require replacing the entire array though? I fail to see how this would be that much cheaper than a 2A5 type conversion, titanium and tungsten are both expensive materials and if this is for all of the special armour, that's quite a lot of material. I also think that tungsten seems quite counterproductive to use because it's so heavy (then again, the US uses DU, though it might not be entire plates), using titanium is quite plausible but for it to only gain 1.45 tonnes with a substanial protection increase (600mm+) seems too good to be true. I find it's quite hard to get good weight numbers on the leo 2 though, even KMW lists the 2A4 as 55.1t all the way to 62.5t (probably 2A4M with wedges). Still, as far as I can find for the M1A1HA all of the extra material was for the turret front, if the 2A4 had it distributed across the 60° arc.... it would need substantially more weight and the M1A1HA isn't light in the first place, quite a bit heavier than the 2A4s. Well, Krapke gives 4290kg with mantlet for the gun and 3100kg without, I'm assuming he's including the gun cradle in this. This matches that Swedish firing table perfectly. That's for the 2AV.

Well, yellow seems to match the leopard 2 "improved" scheme nearly perfectly, for 700mm it shows 30% protected surface which matches the graph on the right, same for the 600mm protection, it's just above 40% for both. That's only from straight front though. I don't think D tech was ever a main armour technology, it seems to be exclusively add-ons, I mean, getting 700mm odd protection out of 860mm LOS seems way too much without adding appliqué. As for C tech, I meant the red graph, it's still too much for the weight difference, but I don't know what else it could correspond with. Hm, does it mention wether or not add-ons were used? While I consider your statements and such quite reliable, you have to understand I don't want to just assume you're correct without evidence, still thanks for the info :). (that only makes me even more confused tbh)

Well, it would've been a prototype if anything, but the similarity is too striking for it to be a coincidence, perhaps it was just a round with the same function and rough dimensions. If this is true, then I agree, but I don't know for sure. Yep, it seems only Germany fully realised the 125mm potential (atleast looking at the Krapke threat diagram) although the leo 1 part probably isn't correct.

Thanks, yeah I also confirmed it with my Swedish friend, though he isn't part of the military in any way so he didn't know 100%. That the "Vappenvagge" also includes some smaller other bits makes sense and would explain the rather high weight, though it does seem like the "trunnion" or gun cradle is indeed atleast more armoured than the proposed 25 + 25 like on the leopard 2K diagram. Makes sense as I've talked to numerous leo 2 crew some of which told me they "tapped" on the trunnion and thought it didn't sound hollow. And yeah, these guys do actually know more than the average person as they're very much interested in this kind of thing. Ah, that would make sense yeah, I guess this is the simplest solution and probably the most likely. Oh, interesting, I was wondering why they seemed to look more German than Swedish (admittedly, they're quite similar languages). So, if it doesn't take into account the "inert" parts that would be more reasonable, I'm still very confused as to the red graph (in the middle), it doesn't seem to portray C tech as the values are incredibly high for such a small weight difference (55.15t -> 56t). Yellow seems to match the graph on the right, so B pakette + D-2 wedges, but I'm curious as to the other ones.... perhaps a "C tech" pakette + wedges? Or D-1 and D-2?.... We don't have a lot to go on, I'm hoping you have more info on it so we can figure it out with a bit less speculation :D.

Well, yes and no. Challenger 1 in this case refers to the Challenger 1 and not Challenger 1 Mk 1 as a lot of people seem to think. They say it's only able to stop T-72 tank rounds at ranges above 1km, now they supposedly rated the 125mm at 460mm DU and later in 1981 they rated the tungsten 125mm at 475mm. I do have to point out how this table seems quite inaccurate or atleast inconsistent, even if it just refers to the hull armour, both the T-64 and T-72 reach higher than 270-290mm. So, personally I'd put the turret more at around 470mm or so and the hull at 325 against WP ammo, against long rods.... it's going to be less than this. I've noticed that as well, they for some reason think the 2A4 was poorer armoured than the stillbrew chieftain, something I find quite funny. The hull is obviously superior on the leo 2 and the turret especially in the frontal 60° is also superior or at the very least equal. According to this page: The stillbrew package in 1985 only managed to resist L23A1 (I assume it's L23A1, L23 is also possible) only at 1km, penetration for L23A1 according to another book (maybe the same one, but I think it's about the Challenger 1) is around 460mm. So, ~450mm of KE protection at the tested spots isn't far off let alone superior to the 2A4's ~430mm which was achieved by firing what looks to be DM53 at it. Right hand one was used for turret testing according to that slide and it looks an awful lot like DM53, the left one looks like DM33. So, considering L23A1 is notably worse than DM53, I think it's safe to say it would do worse against a 2A4 turret than DM53 and the protection given by the armour would "increase" as a result. All of that is from a stricly frontal attack, the sides of a 2A4 are also fitted with spaced armour and the LOS of it would reach around 620-640mm if hit at a 30° angle. The Stillbrew chieftain on the other hand ranges from ~160mm at the front corners to ~86mm at the flat turret sides, neither of these seem really better than what the 2A4 has to offer. I also have to point out that it seems the Brits didn't realise that long rods actually perform better at angles than against flat armour, so to the left of the gun (from our POV) is only 120mm cast + ~60mm rubber + 125mm steel at 60°, which against a long rod won't perform as well as the right side which is 150mm cast + 60mm rubber + 150-215mm steel. So in effect, the left side of the turret is quite a bit weaker than the right hand side despite probably having similar LOS values. That's also why I consider the statement in the outer right column of that picture to be quite naive: Reposted image for easier reading: So, despite their own round already penetrating it from 1km or so and the protection being quite inconsistent, they think it'll stop future 125mm long rod ammo? L23A1 is already a little bit worse than 120mm DM23 in terms of raw performance, 3BM32 and 3BM42 I highly doubt will have any issue with this armour at most combat ranges. So either they didn't think the Soviets couldn't make better ammo than they did, or they didn't understand that long rods perform better against sloped armour and LOS being equal doesn't translate to the afforded protection being equal. Either case seems likely IMO, especially considering their track record of underestimating/misjudging Soviet ammunition. Anyway, I think we need to stay critical even of their official documents as they seem to be wrong or inconsistent in quite a few cases. Yup, just like their preferance for not having a unitary sight, they seem to often come to the wrong practical conclusions.

Oh, that tabel in the "documents for the documents god" thread? Interesting, I completely forgot about this, from my (limited) understanding of Swedish, "Vapensköld" I think means mantlet, "Vapenvagga" supposedly (asked another person too) means guncradle, I'm asking a Swedish friend of mine to confirm though. Thanks! Engines really aren't my strongsuit so it's nice to see an explanation Yeah I remember that Always cracked me up when I saw those pictures... Yeah, I agree, I think 250mm is also quite high, though I guess it's possible in some areas. This has been bothering me for some time now.... And the more I think about it, the more I'm convinced we'll never know until someone actually involved with the tests tells us. My theory is that the values we have were tested but the colour scheme is more or less based on that but filled in the "blanks" with simulation of material thickness, think Warthunder like penetration mechanics with pixel projectiles. What I'm not sure about is the graphs where we can see the different "versions" with the B tech version on the left with all the different angles and protection %s and the leo 2 "improved" on the right, are those "only" showing the crew compartment coverage or is that including all the visible armour? Yeah it wasn't the best, still I think it's complacent or naive to think this "new" ammo type isn't much better or has better potential/ working mechanism than APDS. I think it's probably still better than APDS against complex targets if they're not too spaced or with too thick layers. Yeah, until 1981 where the Iranian chieftains got a kicking.... that was a pretty nasty surprise I think for the Brits.

Interesting, didn't think they reached that high, I'm assuming that went down over the course of the war or? Where did you get that? I've been trying to find good info on it but... it's hard to get specifics, I also have to point out that the trunnion might've been changed going from 2A4 to 2A5. If you look at 2A4 pictures from the inside, the trunnion is painted (probably against corrosion) while that doesn't seem to be the case on the 2A5s, if the pain was indeed against corrosion, that means the trunnion on the 2A5 could be made of a different material, not needing the paint to protect against corrosion, titanium would fit in this case. The switch to a different material could be explained by the wedge of a mantlet adding quite a bit of extra mass (and therefore protection), lightening the trunnion could be a reaction to that, ofcourse, that's just speculation. Odd, heavier engine that produced less HP and wasn't much more reliable if at all? Was there another reason for it or just a less impressive part of the tank? I have reason to believe the numbers in WW2 ballistics are wrong, while I do realise I'm about to post a link to the WT forum of all places, I can guarantee you that Conraire and atleast two other people most definitely know what they are talking about as they have done a load of research. Way more than I have and probably more than the vast majority of people interested in this topic. That said, they're not flawless in their assessments and are still learning (aren't we all?). So, 240mm I find highly dubious, maybe it would reach this against the cast armour of the M60s that had the lower hardness, I'm not entirely sure if the angle plays a role or if lower hardness is always xx% worse. Still, I don't think this picture is entirely wrong: Remarkebly, an SB picture that doesn't seem too far off, obviously, the turret ring isn't ever going to reach 254mm but the rest seems plausible. Yeah, then in that case 20% does indeed seem more likely, I do wonder how exactly the tests were performed though, I've seen some sporadic mentions of cast armour deficits not being as noticeable at higher obliquities, is there any truth to that? True, but technically even a leopard 2A6 wouldn't survive a 100mm AP to the underside of the wedge if it bounces down into the hull, while I know that's a pretty weird thing to bring up, what I'm actually trying to ask is: do we know the criteria for what they considered a "penetrating hit"? I've started to wonder a lot more about this after I've been reading the Swedish powerpoint on the trials, in their renders of the tanks you can see they only colour some areas and probably consider the others "inert", yet we don't get that info on their charts, same with the area around the mantlet for the 2A5 proto, there's small slits that seem vulnerable, was that intentionally "calculated" or just an artifact of the way they did their simulation? Same goes for the leo 1A3 turret, though it does seem to have a slightly more "homogenous" armouring of the front. I'm waiting for new measurements some people were going to do on the M60A1 turret, the angles don't seem that easy to get right just from drawings alone. Yeah, IIRC, army standards were the (in)famous 50%, while Navy seems a lot more like the Russian standards (75-80% or something). Kinda curious as to how much the values would differ if they used different standards. Yes, I agree. Yeah and honestly that's something that bothers me, it just doesn't make an awful lot of sense to me, maybe I looked at too many articles praising the armour protection of the M60s or downplaying the leo 1 armour but..... Yeah, I've noticed the different "priorities" or "accents" Germany, US and UK put on armour protection, what I found particularly curious is how the UK in the Burlington Chieftain research basically considered 115mm APFSDS equivalent or "probably" not much better than 105mm APDS. With spaced armour there's always that random factor at play, or atleast that's what it looks like. I would agree, we need an entire array of pictures and overlayed onto a diagram to see where exactly it was taken, a single picture doesn't say that much. While that 254mm LOS figure seems to be the most common one for the cheeks , I've not seen any other official document state that 300mm or so is wrong, maybe the 254mm figure is an average across the frontal arc (30-45°?) or just a minimum when looked at from the front. The mantlet does seem to have more though, I don't think 254mm is entirely correct for the entire turret, the mantlet seems closer to 300-350mm to me. Anyway, from a purely frontal attack I guess the 1A3 really isn't that far off from an M60A1 turret in terms of raw protection, but it probably wouldn't stand up nearly as well against multiple hits or heavier shells would it? Those thin plates seem like they would buckle quite easily even if they defeated the round.