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The 240mm part did not make from steel, but light metal according to @Militarysta.(he mentioned it is made from titan). In this case the 240mm part gives around 200mm protection. So, if you assume that gun mantlet has 30mm fore and backplate, this gives around 260mm protection from frontal arc, so you still have around 55mm "unexplained" protection. But i think the mantlet armor is a simple spaced armor, or maybe there are 2 bulging plates inside.

Longrod calculator is not really useful tool for the penetration calculation of modern APFSDS. DM63 has not monolit but segmented penetraton. Furthermore, the longrod calculator cannot calculate with the significant improvement in the mechanical properties of heavy metal alloys. https://longrods.ch/downloads/2001 Kinetic Enercy Projectiles-Development History,State of the art, Trends.pdf see Table 1

550-600 mm protection value for the turret front is totally in line what the '5-coloured' chart in the swedish presentaion suggests for the C-tech armor

I think this 350mm came from the 'famous' british docoments. But u missunderstood this value. This means, the Leopard 2 was protected against 350mm KE threat in 60 degree frontal arc. so, this value is rather a "lower edge" of the protection, or you can say: "there was at least 350mm protection in 60 degree frontal arc". But this value tells nothin about the main armor elements' (e.g: turret front) protection level.

I would like to draw your attention to 1 more interesting thing, here: On the slide had been represented 2 shots from 30 degree AoA (Shot 7 SWE and Shot 1 SWE), and there is a very significant difference between the protection values. But if we compare the Shot #7 (SWE) to the Shot #1 (GER), we can see that the difference between them (758/720-1=~5.5%) is almost the same to the difference between the LOS thickness of the armor from 20 and 30 degree AoA. So, this coupled with the other 3 pairs of shots (mentioned in my preivious posts) from same AoA strongly underpin the view there was no difference in (at least) the base armor of the GER and SWE versions turrets. I think the Shot #1 (SWE) was just an outlier due to a lucky strike 😊. I also note that in the case of the hull armor there was a significant difference in the protection level of the heavy skirts, but there was no add-on armor on the skirts. And the outlook of the Strv122 heavy skirts are similar to the C-tech skirts. Futhermore, the protection level of the glacis with B-tech armor could be around 380mm. And in the british document Germans claimed that C-tech armor increased around by 20% the performance against KE-threats. 380*0,2=76mm. It is almost tha same to the difference between the glacis protection of the two versions Shot #1 (GER-670mm and SWE-750mm) So, what if the actual difference between the GER and SWE versions was that the swedish version combined the B-tech turret with C-tech hull? This explanation would also solve the question of "were there multiple add-on armors or not" It seems, Germany originally promoted the Leopard 2 Improved with B-tech inserts and with add-on armor. This can be logical, since according to the original plans, the Germans wanted to upgrade many more Leopard 2s (than they after actually did, and than they C-tech armored Leopard 2 had), and as several people mentioned before, it is likely that in this case the older tanks would have been upgraded first. In addition, in Mannheim the Leopard user countries decided together about the technical specification, and the Netherlands only had B-tech armored Leopards. And also keep in mind, that the final prototype of the L2A5 was made from a 5th batch Leopard. So, it is possible Germany promoted the same version to the Sweden. However, this configuration did not fully meet the protection requirements of the Swedes, which is why the modification was necessary. And that (use C-tech hull instead of B-tech) actually seemed like the easiest (or the only off-the-shelf) solution.

Not, beacuse this was not true in the case of the hull. That’ the point. But what do you think what was the reason for the different protection values of the GER and SWE versions? maintenance, for example. and you forget that the cold war was ended and Germans can think that protection level can be enough. But based on your logic, it is hardly understandable, why just the light skirt was changed on the last 75 tanks, if KMW stated that D-tech armor had been ready in 1991? To be honest it would be more logical if they change at least the heavy skirt elements as it was the weakest area of the armor from 30 degree of angle of attack (in other words: it gave the lower edge of the protecion level in 60 degree frontal arc). No, not just the Shot #2. The Shot #11 (SWE – 379mm) and Shot #6 (GER-371mm), or the Shot #3 (SWE-1480mm, GER- 1475mm). That is 3 shots (with Shot #2 what you have already mentioned). I think it is enough proof for that there could not be difference in the base armor. And to compare the estimated protection values from different angle of attack is not too lucky thing, beacuse there is a very complicated geometrics here. If you compare the Shot #7 and #1 (both for SWE), you can see 720 vs 810 mm protection level from same angle of attack. The first one is lower than the Shot #1 (GER- 760mm), which is quite plausible, as higher the angle of attack lower the armor’ LOS thickness. So, it is possible the Shot #1 (SWE) was just a very lucky/unlucky (depends on the point of view) shot. Except the fact that the TVM participated on the Swedish trial. Sorry, I made a mistake here. I want to say that TVM 2 also had a B-tach armor. What I have read it was made by the modification of the Fahregestell-Nr 20823 with the licence plate Y-567056 (MaK made vehicle from the 5. batch).

BTW, it is also possible that the Germans decided to use the B-technology turret for the L2A5 upgrade because they wanted a uniform program with the Dutch, who, on the other hand, only had earlier series tanks. And by the way, the TVM 2, which was the final prototype of the Leopard2A5, was rebuilt from the previous KVT vehicle.

And we also have to note that TVM 2 (this was built in "Mannheim configuration") already had a wegde shaped turret side armor in contrast to the TVM Max or the KVT.

Do anybody know what was the weight of the turret add-on armor (w/o roof armor)?

except that in the case of the hull they kept the C-tech armor. It seems quite logical that they did not want to use different internal armor in the hull and turret. and the TVM, which was a prototype (or pre-series version?) for the A5 alsi had a C-tech armor.

I can accept your arguments. In this case the 5 colour lines probably show the evolution of the Leopard 2 protection. Purple – B-tech, Red – C-tech, Yellow – Leopard 2 KVT (Leopard 2 Improved – B tech+add-on), and the blue or the green line represents the Leopard 2 TVM. However, this still does not answer the question of whether there were several add-on armor solutions. You showed some alternative readings, but I think these are incorrect. If the D-3 would mean the combination of D-1 (in this reading: internal armor) and D-2 (in ths reading: add-on armor), it would be represented as a combination of the D-1 (pakette) and D-2 (Vorsatz-module), not as „D-3”. And as the technologie-combination of B-tech base armor with add-on armor represents the Leopard 2 KVT’ armor which had a full add-on armor coverage, I think that reading the D-1 is one part of the add-on, the D-2 is the other part of the add-on and the D-3 is the full add-on armor, is also incorrect. Even if we assume the D-1 refers to the D-tech base armor we still have two add-on armor solution. However, my main argument remains unanswered. The protection level of the „german” and „swedish” version turrets are the same from same angle of attack. It implies there is no difference between the base armor. But it (same protection level from same angle of attack) is not true in the case of the hull. So, the only possible answer for it is that there were two versions of (at least) the hull add-on armor.

The picture is from a KMW presentation. And i think, the KMW knows much better than anyone who wrote a Leopard 2 book what armor type was the 3. generation. The introduction dates of the 1. and 2. generation armors are also very telling. 1979- start of the serial production of the Leo2 with B-tech armor; 1988- serial production of Leo2 with C-tech armor. So the picture clearly refers to the interior armor' generations. and there are many sources and evidences for that the D-tech armor was existed/developed as a drop-in solution. I think the development of the add-on armor package within the KWS program, was simply independent from the development from the interior armor package development. My problem was only that, I'm not sure ( or rather: I strongly belive) that D-tech interior armor package was not applied neither on the Strv122 nor the Leopard 2A5. Latest informations about the A7V also suggests that the Leopard 2A5 turret does not incorporate the D-tech armor. (the statement that A7V' hull protection - with the D-tech armor - reached the same level than the turret, suggests different interior armor packages for the turret and the hull)

I think your 600mm figure came from the "famous" british document. But I think u interpret incorrectly the document' protection figures.

there are many controversial informations about the L2A5. "the remeaning energy is absorbed by the improved basic armor"....as the L2A5 built from earlier series Leopards' turrets the improved basic armor easily refers to the C-tech armor. Ans as the hulls came from the latest series Leopards it seems logical that the turret armor upgraded to the same level than the hull. but on the other hand the third generation armor was definitely the D-tech.

Yep, my understanding is a speculation, as there is a puzzle, but I dont have all pieces …so I have to speculate…but I do not think that anybody would have a clear evidence to that what type of armor Strv122 has. But u also speculate when u use the weight figures to underpin your opinion. I think these weigth figures are also very uncertaint. For example, in the „famous” british document the germans stated that the D-tech armor „can be fitted as drop-in packs to the existing turret and hull of Leopard 2 with no weight penalty”. But, what do we know from the swedish slides: the purple and the yellow lines are sure (purple: basic „B-tech” armor, yellow: Leopard 2 Improved) but we also know this slide: if u compare the protection levels from same angles (e.g: „blue” 2 for both the GER and SWE version, or „pink” 11 and 6 for SWE and GER version, respectively), you can see that the „german” and „swedish” solutions’ protection level are same. Which implies – and it is also logical if you want to compare the effectiveness of the add-on armors – that in this test the „swedish” armor configuration also had a „B”-tech interior armor package. And it seems quite logical that the armor configurations that were tested are shown on the slide in question (with the 5 colour lines). So, if the Leopard 2 with B-tech base armor was tested with 2 versions of add on armor, it seems logical, that this result was shown on the slide. So, that is why i think that the blue line is the B-tech armor with the „swedish” ( or Mexas-H) add-on. Furthermore, I think it is not a coincidence that C-tech armor also presented in the „technologie-combination” table. And if the blue line is the B-tech base armor with the „better” (Mexas-H) add-on armor, which technologie-combination has higher protection (green line)? I think the answer is the C-tech base armor with the „better” add-on armor. I think u read the graph incorrectly. The share of the protected area at least 400mm is the same in the case of the yellow and the blue line. (and the green line in the case of „at least 350mm protection”) What u mention is very illogic I can not follow u. There were definitely 2 versions of add-on armors which were tested and compared during the swedish trial. (These called in the presentation „german” and „swedish” solutions. I know the „swedish” solution actually was the Mexas-H developed by the IDB Diesenroth.) And these solutions had different protection values, especially in the case of the hull add-on. And we do not forget that the hull add-on armor was tested also on the M1 and the Leclerc tanks, so the hull add-on solution was not applied exclusively on the Leopard. As I mentioned earlier in the case of the turret there was no „measurable” difference between the „german” and the „swedish” solutions, so it is probably, that the wegde armor was the same in both cases. But it was not the case of the hull add-on. And on the mentioned slide there are D-1, D-2, D-3 add-on armor solutions.

Are u sure? Here is the picture from the Swedish document: Purple: B-tech armor Red: C-tech armor Yellow: B-tech armor+"original/german" add-on armor blue: B-tech armor+"swedish" add-on armor (I think it beacuse this composition was tested on the Swedish trial to compare the "german" and "swedish" versions of the add-on armors) Green: C-tech armor+"swedish" add-on armor ( I think it beacuse this seems logical based on the tested armor combinations. But there is no indication for that this armor composation was actually tested, so I think this armor composation was the choosen/propsed for the Strv122) So, I think the Strv122 has C-tech base armor.

I think the main problems is there are too many paralell R&D capacities, and both countries want to retain it' capabilites in certain areas. I mean if the 130mm gun will be accept for the MGCS the development of the 140mm gun will be sunk cost for the Nexter and it very probably means the end of large caliber gun development at the Nexter. If we look at the Fremm frigates we can see that more or less just the ships' bodies are common. The sensor suits, weapons differs significantly on the french and italian ships. In the case of MGCS in theory it can design to it can use both the Nexter' and RM' IT architect and Thales/Hensoldt sensorsuits. Indeed, this solution will rise the costs significantly. But to design a turret which can fit to both the 130 and 140mm gun and the different autoloaders...uhhh... IMHO french are a bit cheeky as they are the leaders of the FCAS but in the case of MGCS (which is lead by - in theory - the Germans) they want it will be made by the KNDS in which the Nexter has a higher share another problem is that the industrial partners participating in MGCS and FCAS are different, so it is not very possible to come up with some kind of compensation: if I get less work from FCAS, I ask for more from MGCS

The 28-77 means the aspect of the armor' layers. I mean, in the case of 60-105-50 armor the total thickness of the array is 215mm. So, the aspects are 60/215~0.279 and (60+105)/215~0.77 The charts below that show some parameters' dvelopment in the certain layers. Neither me know what are on charts in every cases. But, the charts labelled with "V" and "L" are the velocity and lenght. So, you can see, that in the case of the 60-105-50 armor there is no velocity drop and length erodation in the middle STEF layer. But, in the case of the 5layers armor (50-35-50-35-50; T80BV and T80U), in the first STEF layer there is some velocity drop and some length erodation. In the second STEF layer there is no lenght erodation but there is a significant velocity drop, which resulted in significant lenght erodation in the last steel layer.

The problems come from this pheomenon in the case of the 60-105-50 array: While in tha case of 50-35-50-35-50 array the STEF acted like this:

Both this article and Mikhail Rastopshin in this article stated that it can.

Interesting thing about the STEF, when the soviets tested the 60-105-50 array against the Hetz, they were extremely surprised when the Hetz perforated this array from 2km. Hetz has around a (nominal) 130mm perforation at 2km against a target sloped at 68 deg. It means, the STEF worths almost nothing against the Hetz. Especially, if we take into the account tht 60-105-array in its own (without STEF) act as a spaced armor, which gives around 10% high protection than if it would be a simple 110mm steel plate. So, it gives us, that 105mm STEF delivered only 8-10mm RHA protection against the Hetz. 105mm STEF' weight is equal around 27mm RHA, so it gives us the ME coefficient could be in the 0.3-0.35 range But in the T-80BV/U glacis soviets used a 50-35-50-35-50 array, which gives around (nominal) 200mm protection. So, even if we take into the account that 50-50-50 array act as a spaced armor which gives around 10% higher protection we get the 70mm STEF gives around 30mm RHA protection against long rod penetrator. 70mm STEF' weight is equal around 18mm RHA, so it implies ME coefficient could be around 1.6-1.7.

Ok. Understood. BTW I found a paper about the ceramic armor which claims around 5 ME coefficient (against handheld weapons' bullets). https://patents.google.com/patent/WO2002068373A2

Hi SH, Thank you for your answer. But I think remains some questionmarks. First: logically in the case of an efficiency measure higher number means higher efficiency. So, efficiency value above 1 means that given material is „better” than the RHA. I think our interpreation is same in the case of ME. According to your interpretaion 100/0.34~295 kg SiC do you need to reach the same level of protection of 100 kg RHA. But this statement is equal with that 100kg SiC provides you 34 kg RHA equivalent protection (what I said earlier). But I think your interpreation about TE is not consistent with the table’ statement. See your example: we have a „material X” with 2 ME and 25% densitiy of the steel (around 2 g/cm3) so, to reach 200kg RHA equivalent protection we need 200/2=100kg of „material X”. But if our 200kg RHA plate is 100mm thick (it means it is roughly a 100mm*500mm*500mm steel plate) we need 200mm of „material X”, which gives us TE=0.5. But substitue the values of the SiC (0.34 ME, and 0.9 TE, density ratio=3/7.85~0.38): 200/0.34=588 kg and you can reach this value if you use a 770mm(*500mm*500mm) thick plate. Which gives us 100/770~0.13 TE. According to your interpretation the TE=ME/density ratio, where density ratio=steel/material X But in the table the TE=ME/(1/density ratio)! Let’ see the STEF: it has a density ratio 7.85/2=3.925. Let’ take my equation TE=ME/(1/density ratio)=0.63/(1/3.925)=~2.45, as in the table don't get me wrong i don't think armor developers are stupid. I simply do not understand how, based on the given table, it comes out that it is worth using ceramics in the armor. But if I understand correctly what you say, these values are not "actual" TE and ME values. But don't you know how much I argued on other forums, typically with Russian tank fans, who, typically based on such misinterpreted tables, always wanted to conclude that Russian tanks are the "kings" based on this, is it possible that in the Leopard2 "D"-tech armor the steel backplate of the ceramic "sandwiches" changed to the "mysterious" wolfram-titanium alloy?

Sorry, if my question will be stupid, but this table suggests there is no better armor material than the "good old" steel. According to my understanding ME efficiency shows the armor efficiency when we keep the plate' thickness constant, and TE efficiency shows the armor efficiency when we keep the late' mass constant. Take an example: in the case of SiC a 20mm plate has a 20*0.34=6.8mm protection. In the case of TE efficiency 20*(7.85/3)=52.2mm thick plate has a same mass than a 20mm steel plate. 52.2*0.34~18mm which gives us 18/20=0.9 TE coefficient So, why the hell makes anybody armor out of anything other than steel? Especially if we take into the account that HHS gives us around 1.1 ME/TE coefficient. Is it possible that use a backing plate and appropriate interlayer material in a structure something like this, improves the ceremics' performance drastically? Or just me understand wrong something int he abovementioned table?

This is the estimated protection level against KE threat