Scav

Brits paying for new turrets? 

More likely they end up buying surplus M1A1 turrets (from those vehicles converted to CEVs and bridgelayers or whatever) and upgrade them.
Also, weekly reminder that Drummond is a hack.

I believe so, but there is no direct confirmation, only facts serving as indirect sources (the added weight, the adoption of new side skirts, the fact that the hull armor access hatch was welded shut, the Dutch orderiing their tanks to the Mannheimer configuration just like Germany, etc.).
 
 
There have been different versions of Laviduce's estimations. He originally believed the right turret cheek to be weaker than the left one, but a closer look at the graphs from Lindström's presentation show that the right cheek actually was better protected. The size of the EMES-15 gap seems to be a bit too much, i.e. overall armor module thickness seems to be nearly identical on the lower right and the left cheeks, but the former includes addiitonal space between the modules, enhancing overall protection.
 
Note that the thickness of the armor array below the EMES-15 sight is pretty much the only place where the thickness was guesstimated, while for the other places actual measurements were available. It also seems to be a place with a bit more variable thickness, as the front and rear walls of the EMES-15's cavity are not parallel. On the left edge the frontal armor module seems to be about 400 mm thick.
 

 
Note that the protective shutters of the EMES-15 is located ontop of the armor, the cavity starts behidn them:
 

 
 
This "book" happens to be the German wikipedia article on the Leopard 2 (in a slightly outdated form). The authors of the article happen to have a rather limited understanding of the armor generations, for example due to their generalizing and simplified writing style, they claim that all Leopard 2 variants (including the original production model from 1979 and the current Leopard 2A7 from 2014) feature armor in C-technology. The armor in D-technology is only mentioned as side skirt armor, because Lobitz mentioned only the side skirts directly.
 
 
The problem is that most authors do not use the terminology with "B", "C" and "D" technology armor arrays in their books and do not specify how the armor was changed. They mention that the late model has "improved protection" or general armor technology ("armor in C technology", "armor in D technology", "3rd generation armor", "4th generation armor") without mentioning anything specific about where the armor was used - if the Leopard 2A4 from 1991 would only have the improved skirt armor according to F. Lobitz's "Kampfpanzer Leopard 2 - Entwicklung und Einsatz in der Bundeswehr", then other authors could refer to the same changes in skirt armor with their more generic descriptions.
 
However I am not sure if Frank Lobitz doesn't only mention the skirts, because it is the only visible change. He didn't specify anything about the base armor remaining identical to the Leopard 2A4 from 1988 (although he mentioned there, that the base armor was changed), he might not have been sure while writing his book. Note that the table listing the changes mentioned by Voodoo is located on page 126, it specifically mentions the skirts, but on page 127 is the following image with caption:
 

The German caption of the upper photograph includes the word "auch" (in English: "too", "also"), which is excluded from the English translation. This might either mean that the Leopard 2 from 1991 also featured armor in "D" technology in the chassis and turret or that it also features "D" technology armor like other tanks. The problem with the latter is that nearly two dozen pages in front of this caption are focused on describing the older versions of the Leopard 2. so the whole situation with Lobitz's book is rather odd. To add to this confusion, he mentions in the table in page 126 that the heavy side skirts would also be in "D" technology (albeit looking identical to those fitted to the Leopard 2 from 1988 with "C" generation armor), which would mean that at least. I don't really see the point in changing only the skirt armor, if the rest of the armor remained completely unchanged - specifically if it is only the light skirt (which offers no protection advantage, but is more expensive, as HHS costs several times more than perforated RHS in rubber). If the composition of the heavy skirts was also altered, the hull would be better protected from impacts at an angle than frontally...
 
Also a curious fact is a snipplet from page 183, where the author mentions that the Leopard 2A4 from 1991 uses "second generation light side skirts" (in his nomenclature, which probably isn't official, as other authors use "second generation" in reference to the armor in "C" technology), while the Leopard 2A5 and 2A6 use "third generation light side skirts" - the layout seems identical, but the location of the screws is different (maybe the thickness too, but this might be the result of artistic freedom of the man who made the sketch showcasing the differences). This might again point to a difference in D-1 (first type of skirt armor made in "D" technology) and D-2 (second type of skirt armor made in "D" technology) armor arrays being used.
 

Fresh supply of tea always close to hand!
 

This is what Frank Lobitz writes in Kampfpanzer Leopard : Entwicklung und Einsatz in der Bubdeswehr(Development and Service in the German Army):
 
Talking about the 8th production batch: 
"In contrast to vehicles of the sixth and seventh production lots, those of the eighth production lot features light side skirts that incorporate D-technology. (KMW)"
 
Further, he goes on about the prototypes for the 2A5:
"....A maximum of 62.5 tonnes was set as the weight limit. Chief efforts were conducted in the field of armour protection. The add-on armour packages were designed with D-technology(similar to fourth-generation spaced composite armour) and,depending on their location on the vehicle, were either integrated(turret front/chassis) or mounted on the top(turret roof). For the first time  add.on armour modules were mounted in front of the original armour of the turret front and chassis, and this changed the appearence of the vehicle significantly."
 
Sorry for barging in to your conversation and if not understanding your question..

Fixed that for you.

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?
 

If they actually manage to get the 120mm Smoothbore, that'll be the most important advance in the whole Challenger family since the TOGS on the CR1 Mk 2...

I would say something but it's a classified thing.

The yellow graph might correspond to the Leopard 2A4 with "D" technology armor (production start in 1991), not the Leopard 2A4 with "C" technology armor (production 1988-1991).
 
I can say that the late Leopard 2A4 turret front with the latest armor ("D" technology) did survive a direct impact from the LKE1 APFSDS fired from 2,000 m distance without the projectile reaching the inner layers of the armor array. This round was later type-qualified as 120 mm DM43 APFSDS (given its 600 mm penetrator length and 1,740 m/s muzzle velocity, it should be able to penetrate about 600 mm of flat armor at this distance). The sources for this is classified, unfortunatley it cannot be shared without potentially getting some people in trouble.

don't know where you get 455HB for serial postwar casted soviet turret, but T-62, T-72 and T-64 uses SBL-2 steel which has hardness up to 277HB(Impression Diameter - 3,65mm) and tensile strength up to 882MPa 

made pic for better understanding 

OH YOU HAVE NO IDEA HOW THE BLOODY SHITSTORM LOOKS LIKE IN ANOTHER SIDE OF THE OCEAN

Given that the Leclerc ended up with lower shooting scores in all trials and competitions, I seriously doubt that there are issues with firing on the move. At the maximum speed that the Leopard 2 realistically reaches off-road, it can accurately hit its targets. Driving along flat roads with higher speeds shouldn't negatively affect its accuracy.
 
I guess you are mixing something up with the Leopard 1, which could not accurately fire on the move at speeds higher than 20-25 km/h...

The there were tungsten and DU versions of the XM827 during development, but the DU version was prefered in the end (still canceled in favor for the M829 though). Likewise the US Army tested WHA and DU versions of the XM833. The article from the ARMOR magazine doesn't mention any materials, but it also includes one mention of the M735A1 (with DU penetrator).
 
At the time, DU alloys could probably achieve better performance, but the 120 mm DM13 should be better than the M735 APFSDS and its M735A1 sub-variant, simply based on physics.
 
 
It is availabe on the website of the German patent office, the European patent office, Google patents and many more
 
https://worldwide.espacenet.com/publicationDetails/biblio?CC=DE&NR=2234219C1&KC=C1&FT=D#
 
 
Actually it seems that modern tungsten heavy alloy penetrators are usually made with a slightly smaller tungsten content, in some cases as low as 90%. This way it is possible to create alloys with more ductility and/or strength.

The data used by Warthunder for the M735 is simply wrong. It is not possible for the M735 to penetrate the same amount of armor as the DM13 APFSDS at the same distance, given that penetrator length is essentially identical (~313 mm vs 315 mm), but the muzzle velocity and length-to-diameter ratio are in favor of the 120 mm DM13. An older article published in 1982 in the US ARMOR magazine suggests that the XM827 (German 120 mm DM13) has a 20% larger penetrator mass and was able to defeat all targets during the 1976 gun trials by NATO at longer ranges than the M735 (the M735 failed to penetrate some targets).
 
Given the higher drag of the DM13, the M735 might be able to reach the same level of armor penetration at ranges greater than 4 kilometres (assuming deceleration stays constant up to this distances), but the 105 mm rifled guns M68 & L7 weren't considered accurate enough (neither was the 120 mm Rh 120 L/44 firing 120  mm DM13 ammunition).
 
 
The layout of 120 mm DM13 is identical to a patented design from 1972.
 

Patent drawing from patent DE2234219, registered on 12th July 1972. They certainly couldn't take design aspects from other APFSDS ammunition which didn't exist at the time.
 
 
AFAIK the table posted earlier was made by another internet user, who based it on a (de)classified report. He might have made some error when entering the numbers from the paper into the computer, because the DM13's penetrator diamter is listed as larger than the actual diameter of the sub-projectile, which is physically impossible. The penetrator diameters for the L15 APDS, the L52 APDS and the 110 mm APDS are all smaller than the projectile diameter - just as expected.
 
 
The weirdly shaped ballistic cap is in fact a windshield and a very normal design. Several other APFSDS rounds from NATO and the Soviet Union (among them the L23A1 APFSDS, Lekalo and Mango) use the same method to connect the windshield to the penetrator.
The penetrator design and working mechanism is not similar to the Soviet 3BM-15 APFSDS and its sucessors. The Soviets used very brittle tungsten-carbide cores, which were shaped like bullets and embedded into the steel, because they would break otherwise.

 
The tungsten-carbide tips would break off when hitting sloped armor or become damaged when penetrating spaced armor, which significantly reduced the performance of Soviet APFSDS. That is why the tungsten-carbide core was later moved to the rear of the penetator to deal better with spaced and composite armor arrays.

3BM-26, the tungsten-carbide penetrator is located in the fin-section.
 
The DM13 APFSDS uses a penetrator made of WHA; the patent from 1972 suggests that 95% tungsten, 3.4% nickel and 1.6% iron would be desirable. The steel sheat is only added, because of the low yield strength of the WHA, which breaks apart when hitting (highly) sloped armor. The steel sheat apparently doesn't extend over the frontal (separate) section of the penetrator, because the tip always breaks off when impact sloped targets. Furthermore this layout was found to be advantageous against multi-plate armor arrays, as the larger frontal portion would result in a larger hole, through which the main part of the penetrator could travel without being damaged.

Yes, from what I know that's true, but the values don't match the ones I've been able to find:
 
And it's more than just sheathed, it's also segmented with a weirdly designed ballistic cap and the first actual "penetrator" part seems to be similar in function to the ones found in 3BM15 etc (though substantially larger and with a tip reminiscent of L23A1).