StuG III Thread (and also other German vehicles I guess)

[FORMATOSE]

On 11/25/2018 at 3:16 PM, SH_MM said:

That's not reliable, just like the "solid titanium trunion of the Leopard 2, which doesn't exist.

 

Its gun cradle is hollow, right ?

[SH_MM]

3 hours ago, Scav said:

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.

 

According to different German authors (Rolf Hilmes, W. Spielberger, Frank Lobitz) the base armor used on the last batches of the Leopard 2A4 and on the Leopard 2A5 is based on "D" technology. The original armor package for the Leopard 2 (in "B" technology) remained in production until the 96th vehicle of the sixth production batch; starting with the 97th vehicle of the sixth batch, the new armor kit in "C" technology was used. The original Leopard 2A5 prototype (the KVT) was based on a hull made in 1987 as part of the fifth production batch, hence it was  made with the original base armor package, only the add-on parts made use of newer technology.

 

Beginning in January 1991, the tanks of the eight production batch with new armor in "D" technology were manufactured. These tanks were manufactured at the after the late Leopard 2A5 prototypes (TVM 1&2 Max., IVT) were manufactured, for which the new generation of armor has been developed ("D" technology), hence they used this type of base armor. The Leopard 2A5 KVT was send to Sweden, because the newer Leopard 2A5 prototypes were still being tested in Germany, this is the reason for the "German model" using inferior armor compared to the configuration ordered by Sweden (which apparently used "D" technology base armor + add-on parts). The Leopard 2A4 tanks with "D" technology can be identified by the side skirts - they are identical to the ones used on the later versions including the Leopard 2A5, 2A6 and 2A7.

 

(Leopard 2A4 with "D" type armor)

 

The production model of the Leopard 2A5 tanks for the German army was created by mating Leopard 2A4 hulls from the last production batches (with armor in "C" or "D" technology) with turrets from the earliest production batches. The old turrets are used, because they require extensive rework during which the base armor is replaced with new modules in "D" technology. This actually means that some Leopard 2A5 hulls might be better protected than other. There are no add-on armor modules on the German Leopard 2A5 hulls, because it was scheduled for adoption at a later time, it would have been added simultaneously with a new turret with the 140 mm L/48 NPzK smoothbore gun, as this would already require a more extensive rework of the hull (for example modifying the ammo racks to be suitable for 140 mm two-piece ammunition). The Leopard 2A7V will be the first German version too feature hull add-on armor modules, although this might be "E" or "F" type armor.

 

3 hours ago, Scav said:

Hm, does it mention wether or not add-ons were used? 

 

I haven't seen any texts, but a set of photographs of an armor array being tested. It consists of a thick steel plate, a large box labeled "Sonderpanzerung" (special armor), two further thick steel plates followed by a number of several other plates, some of which appear to be non-metallic. I was told that the thick steel plates have a relatively low hardness, but are used to simulate thinner plates of very high-quality (and very expensive) ballistic steel. There is no external armor module.

In front of the armor array is a sign from the German WTD saying that this array is being tested against the LKE1 APFSDS at a range of 2,000 meters.

 

The other photos show the three thick steel plates after the armor array was hit: one shows the exterior of all three plates, each showing the marks of the APFSDS penetrator. Another photograph shows the inner side of the three thick steel plates: two of them have been completely penetrated, while the other one has only a dent of the APFSDS penetrator. There is also a ruler/measurement rod, which suggest that the "Sonderpanzerung" is about 500 mm thick only. The steel plates are about 100 mm thick, but supposedly they are made of mild steel; the actual ballistic steel would be some fancy type of high hardness/triple hardness steel providing a much higher level of protection per weigth and thickness.

 

I actually haven't seen any proof that this armor belongs to the late Leopard 2A4 tank, but I consider the source very trustworthy. This armor was supposedly offered during the early 1990s as a cheap upgrade option to several Leopard 2 users, who didn't want to pay for the more expensive Leopard 2A5 upgrade, which is why I believe this is the "D" technology armor. According to different authors, there are (unconfirmed) rumors about the late Leopard 2A4 armor featuring titanium and tungsten, which might be broadly similar in to the DU armor of the M1A1 HA (at least the M1A2 SEP uses titanium to allow improving the armor protection without increasing the mass of the armor considerably). It is worth noting that AFAIK only the Leopard 2A4 with "D" technology is actually heavier than the Leopard 2A4 with "B" technology, apparently by 1.45 tonnes (at least the weight 56.6 tonnes has been quoted for the late Leopard 2A4). The M1A1 HA upgrade is heavier, but might cover more surface area and might have initially lacked the titanium weight saving measure.

 

I know that the "I have access to secret sources" argument is very weak, but the details about this armor come from a source that is located in one of the countries to which the Leopard 2A4 armor upgrade was offered during the 1990s. As it was never purchased by this country, the documents have only a low level of classification (IIRC every tank commander can access them).

 

2 hours ago, Sovngard said:

Its gun cradle is hollow, right ?

 

As far as I know it should be hollow, at least for the early version of the Leopard 2.

[Scav]

3 hours ago, SH_MM said:

According to different German authors (Rolf Hilmes, W. Spielberger, Frank Lobitz) the base armor used on the last batches of the Leopard 2A4 and on the Leopard 2A5 is based on "D" technology. The original armor package for the Leopard 2 (in "B" technology) remained in production until the 96th vehicle of the sixth production batch; starting with the 97th vehicle of the sixth batch, the new armor kit in "C" technology was used. The original Leopard 2A5 prototype (the KVT) was based on a hull made in 1987 as part of the fifth production batch, hence it was  made with the original base armor package, only the add-on parts made use of newer technology.

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.

 

3 hours ago, SH_MM said:

The production model of the Leopard 2A5 tanks for the German army was created by mating Leopard 2A4 hulls from the last production batches (with armor in "C" or "D" technology) with turrets from the earliest production batches. The old turrets are used, because they require extensive rework during which the base armor is replaced with new modules in "D" technology.

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...).

 

3 hours ago, SH_MM said:

The Leopard 2A7V will be the first German version too feature hull add-on armor modules, although this might be "E" or "F" type armor.

E or F?
Never seen that before, just speculation or do you have a good reason for that?

 

3 hours ago, SH_MM said:

I haven't seen any texts, but a set of photographs of an armor array being tested. It consists of a thick steel plate, a large box labeled "Sonderpanzerung" (special armor), two further thick steel plates followed by a number of several other plates, some of which appear to be non-metallic. I was told that the thick steel plates have a relatively low hardness, but are used to simulate thinner plates of very high-quality (and very expensive) ballistic steel. There is no external armor module.

In front of the armor array is a sign from the German WTD saying that this array is being tested against the LKE1 APFSDS at a range of 2,000 meters.

Interesting....

 

3 hours ago, SH_MM said:

The other photos show the three thick steel plates after the armor array was hit: one shows the exterior of all three plates, each showing the marks of the APFSDS penetrator. Another photograph shows the inner side of the three thick steel plates: two of them have been completely penetrated, while the other one has only a dent of the APFSDS penetrator. There is also a ruler/measurement rod, which suggest that the "Sonderpanzerung" is about 500 mm thick only. The steel plates are about 100 mm thick, but supposedly they are made of mild steel; the actual ballistic steel would be some fancy type of high hardness/triple hardness steel providing a much higher level of protection per weigth and thickness.

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.

 

3 hours ago, SH_MM said:

I actually haven't seen any proof that this armor belongs to the late Leopard 2A4 tank, but I consider the source very trustworthy. This armor was supposedly offered during the early 1990s as a cheap upgrade option to several Leopard 2 users, who didn't want to pay for the more expensive Leopard 2A5 upgrade, which is why I believe this is the "D" technology armor. According to different authors, there are (unconfirmed) rumors about the late Leopard 2A4 armor featuring titanium and tungsten, which might be broadly similar in to the DU armor of the M1A1 HA (at least the M1A2 SEP uses titanium to allow improving the armor protection without increasing the mass of the armor considerably). It is worth noting that AFAIK only the Leopard 2A4 with "D" technology is actually heavier than the Leopard 2A4 with "B" technology, apparently by 1.45 tonnes (at least the weight 56.6 tonnes has been quoted for the late Leopard 2A4). The M1A1 HA upgrade is heavier, but might cover more surface area and might have initially lacked the titanium weight saving measure.

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.

 

Quote

As far as I know it should be hollow, at least for the early version of the Leopard 2.

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.

[SH_MM]

12 hours ago, Scav said:

Yeah, thing is, they don't specify the base armour itself being "D tech" (atleast as far as I could tell). 

 

Both Rolf Hilmes and Frank Lobitz specifically mention that the base armor of the Leopard 2A5 was replaced with new inserts in "D"  technology. During the Leopard 2A5 upgrade process, the turret structure of the Leopard 2A4 is cut open and new armor inserts in "D" technology are installed. For the last batch of Leopard 2A4 tanks Lobitz mention that the tank featured "improved armor protection" and at another place that it can be identified by the new light side skirts in "D" technology... adding one and one together and this leads to the last Leopard 2A4 featuring "D" technology armor.

 

 

This photograph shows two Leopard 2 turrets (from the earliest production lots, as one can see by looking at the ammunition loading hatch) during upgrade to the Leopard 2A5 standard according to Rolf Hilmes. The armor insersts have already been removed, the location of the EMES-15 and the surrounding armor layout is being modified on the turret at the rear.

 

12 hours ago, Scav said:

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.

 

According to Michael Scheibert, author for the (nowadays defunct) Waffen-Arsenal book series, the (first) Leopard 2A4 armor upgrade was weight neutral, i.e. there was no weight gain or loss (although I personally believe that there was some minor difference).

 

The 56.6 tonnes figure is rarely used, but it has appeared in a quite a few articles on the Leopard 2A4 and a number of press releases (for example the company Ingenieurbüro Deisenroth stated in an article about the reveal of the Leopard 2 Evolution upgrade with AMAP armor, that the Leopard 2A4 used as basis for the demonstrator had originally a combat weight of 56.6 tonnes, which had to be lowered by removing the side skirts before the Evolution kit could be added to remain in the desired 60 tonnes weight limit).

It isn't actually confirmed that this weight figure is related to the extremely rare Leopard 2A4 with "D" technology armor (only 75 made for the Bundeswehr of which only 1 still exists) or not - but unless the literature is wrong and the version with "C" armor is actually heavier than 55.15 tonnes, the 56.6 tonnes figure has to refer to the latest version by the method of elimination. In theory the Leopard 2A4 with "D" technology armor might also be heavier than 56.6 tonnes, I've never seen an actual weight value specifically mentioning that it belongs to the 75 tanks of the eight production batch.

 

The Soviets adopted new armor arrays (mainly for the hulls of their tanks) at a much steadier rate, e.g. the T-72B was built with three different armor arrays within a period of just 5 years. West-Germany adopted the new (and more protective) Leopard 1A3 turret just 13 months after the new turret for the Leopard 1A2 had entered production. The M1IP version of the Abrams entered production four years after the M1 Abrams, yet it featured improved armor and a longer turret. So three years for a new Leopard 2 armor package developed at the height of the Cold War doesn't seem implausible.

 

 

This image is from a set of documents delivered by Krauss-Maffei to Sweden and leaked as part of R. L.'s presentations.  It shows the references for the armor packages (although it doesn't mention wether this means that the armor protection is comparable to the Soviet tanks or meant to resist rounds fired by these Soviet tanks). The 3rd generation armor package (which would be "D" technology based on the German naming scheme) was adopted in 1991, yet the Leopard 2A5 entered service in 1995. It was meant to compare to the (armor or firepower of the) FST (Future Soviet Tank), which was expected to enter service in the 1990s and feature a next-generation gun (various different calibers including 125 mm, 130 mm, 135 mm and 152 mm have been mentioned in different articles over the years).

It appears that in fact both new armor packages for the Leopard 2A4 and the Leopard 2A5 were developed after the BMVg (German MoD) requested a higher level of protection back in 1984, which kickstarted the Leopard 2A5 development (a first prototype with add-on armor looking similar to the 2A5 being tested in 1986).

 

Please note that there are three versions of "D" technology armor (D-1, D-2 and D-3). The Leopard 2A4 could use "D-1" inserts, while the Leopard 2A5 made for Sweden could feature "D-2" or "D-3" inserts. I don't think that Krauss-Maffei would choose this "table format" for displaying armor packages, if the "D" technology armor was only available as add-on modules.

Note that the line "Pakete" (armor inserts) also contains fields for the three types of "D" generation armor. Also note that "Technologie-Kombination" means "technology combination" (implying that all types of add-on armor modules and base armor can be easily combined).

 

12 hours ago, Scav said:

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. 

 

It is indeed a very odd situation, I can understand your skepticism. I probably also wouldn't believe anyone saying that he has a classified source showing that a tank had a much higher level of protection than other people consider plausible. I can only say what I have seen and what I've heard.

 

I don't think the M1A2 still has the same level of hull protection as the initial M1 Abrams. The British stated that the later has a protection was only 320 mm against kinetic energy penetrators (from the front?), while the M1A2 offered to Sweden reached 350 mm along the frontal arc (it could be a bit more directly at the frontal cavity, given that the weakest sectioon of the frontal arc is probably the side skirt area at 25-30°). The hull armor was upgraded with the variants M1A1/M1IP (there were at least weight demonstrators welded to the hull front of the M1E1). The hull armor of the Leopard 2 can be upgraded more easily, in the original models there even was a hatch to access the armor inserts (which was shut via bolts), only during the upgrade to the Leopard 2A4 this was shut by welding. In a Canadian Army maintenance facility, they have opened the hull armor cavity of a Leopard 2A4 with "B" armor package (the edges of the plates inside however are oddly soft compared to the rest of the photograph, they might have been added with photoshop):

 

As for the weight increase and the corresponding increase in armor protection, there are multiple factors to consider. First of all, there are differences between both tanks, that shouldn't be ignored. The Leopard 2A4's turret front is about 15% smaller than that of the M1A1 HA, thus for an equal increase in armor weight, the Leopard 2A4 would require only a weight gain of 2.55 tonnes. The 1.45 tonnes that the Leopard 2A4 with "D" technology might be heavier (assuming the 56.6 tonnes figure is correct) than the earlier variants seems to fall a bit short of that, but the question remains wether a M1A1 has the same amount of (turret) armor weight per volume as the Leopard 2A4 with "B" or "C" technology armor. Given the larger frontal profile and the extensive side armor, it seems possible that the Leopard 2A4 has actually denser armor to start with (at least this was the case when comparing the Leopard 2 to the M1 Abrams). Another factor is the side armor: the Leopard 2A4 from 1991 features new light side skirts made of high-hardness steel, which supposedly provide the same protection level at a slightly smaller thickness than the previous type. Also there are unconfirmed rumors about the side armor at the frontal section being different; some Danish soldier claimed that the Leopard 2A5DK has thicker steel side armor than the Strv 122, which at least partly might be confirmed by the fact, that the latter had a slightly lower protection level against RPGs hitting at 90° angle than the Leopard 2 KVT during the Swedish tests. Compared to the M1A2, the Leopard 2A4 has a much larger gun mantlet, which probably wouldn't be able to reach the same protection level (and probably would also have a much lower weight than the main armor).

 

The makers of the video game War Thunder measured the thickness of an early-model M1 Abrams using tape measures and an ultrasonic probe.They concluded that the backplate of the hull armor is 101 mm thick (excluding slope), which seems to be quite a bit. The Leopard 2 - at least on the turret - uses what seems to be a 40-60 mm thick backplate, thus more weight can be invested into special armor with a higher mass efficiency. Maybe the turret armor also follows this layout, at least the people from the War Thunder developer claim that the size of the special armor cavity is only 19.5 inches (I believe without slope). Assuming that the turret backplate is also 101 mm thick and knowing that the measured thickness of the turret frontplate was 38.1 mm, the total thickness of the M1 turret armor would be 634 mm or ~732 mm LOS from the front, which falls into the range of estimated armor thickness from various internet users.

 

It is worth noting that the M1A2 turret in Sweden provided 600 mm protection vs APFSDS rounds along the frontal arc, the armor tested in Germany was however simulating a hit directly from the front (otherwise the armor would be way too thick). So there still could be a ~10% difference in armor protection in favor of the M1A2 (esp. considering that the armor package with DU might be slightly better).

 

There is no doubt that the armor array survived a hit by a LKE1 APFSDS without being fully penetrated, which is why there are a few possible options:

1. The armor might not be identical to the one adopted on the Leopard 2A4 production model of 1991 - however the armor was tested before the DM43 APFSDS was type qualified (which IIRC happened in 1994 or 1996) and it was offered as an upgrade option for users of the Leopard 2A4 with "B" generation armor, so that doesn't seem to be the most likely option.
2. The Leopard 2A4 from 1991 might have a larger combat weight than assumed; it is a really rare variant and no user of the Leopard 2A4 seems to have ever upgraded their 2A4s to a version with "C" or "D" armor package (at least the side skirts have remained identical). 
3. The LKE1 APFSDS being a prototype mgith mean that it actually had a lower level of armor penetration than the DM43 APFSDS - but it probably was always superior to the DM33 APFSDS it was meant to replace (which apparently has ~480 mm at 2,000 m penetration).
4. The Leopard 2A4 armor from 1991 could be highly optimized against KE, potentially sacrificing relative protection vs HEAT. The rumored inclusion of tungsten and titanium would support this, as this would be similar to the DU armor of the M1A2 (at least the SEP features titanium within its armor array).

12 hours ago, Scav said:

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. 

 

I dont think that is very accurate. I've seen a wide range of estimations for the M1A2's turret front (as low as "below 800 mm" and as high as 1,100 mm), yet no accurate measurements have ever been made. The M1A2 models use the same turret dimensions introduced with the M1IP in 1984; at this time 940 mm physical thickness would have been more than any other contemporary tank (T-72B, T-80U, Leopard 2 and Challenger 1 all having 800-870 mm physical thickness along the line-of-sight at most).

How did you estimate the thickness? Did you keep in mind that the slope of the turret cheeks is assymetrical (left turret cheek is sloped more than the right).

 

Also don't forget that this is 600 mm along the frontal arc, so it is achieved by the unsloped armor package already. While the M1A2 Abrams has a combat weight of 62.5 tonnes, the armor weight was likely not increased over the M1A1 HA (at 61.8 tonnes; the M1A2 adds a lot of additional parts to the tank that might explain the weight difference); this is about 3 tonnes heavier than the M1A1 when both tanks are fitted with the T158 tracks.

 

12 hours ago, Scav said:

E or F?
Never seen that before, just speculation or do you have a good reason for that?

 

There have been several statements from various sources hinting that there are more armor generations. When the Leopard 2A7 entered service with the German army, Jane's Defence Weekly stated that it is being protected by a "new generation" of armor in the turret and hull. According to Polish news agencies, Rheinmetall claims that the Leopard 2 turret with AMAP armor provides more protection than the Leopard 2A5 turret, but equal protection to the Leopard 2A7. There are also some mentions about certain exported tanks featuring "improved armor", although it is never mentioned what the point of reference is.

 

It seems rather reasonable to assume that after the "D" technology armor from 1991/1995, armor development didn't cease. The Leopard 2A7V prototype presented at Eurosatory 2016 for example features a different hull add-on armor kit compared to the Stridsvagn 122 (similar thickness, but the size and location of the mounting screws is different).

 

12 hours ago, Scav said:

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. 

 

No, the entire armor array that stopped the LKE1 APFSDS was about 800 mm thick: 100 mm soft steel, 500 mm special armor, two layers of 100 mm soft steel. The APFSDS reached the third steel plate, so it defeated more than 700 mm armor.

 

The Leopard 2 is said to feature some extremely expensive steel types, which provide high levels of protection. For example according to the company that provides the very few cast steel elements for the Leopard 2 tank, the cast steel has a hardness of  350-380 HB on the initial model and 380-420 HB on the Leopard 2A4 and Leopard 2A5. The turret shell of the initial model was made of HFX 130 steel with an average hardess of 380 HB; it seems likely that the Leopard 2A4 tanks with "C" and "D" generation armor use different steel with a hardness of more than 400 HB (note that on the photograph showing the Leopard 2A4 turrets being upgraded to the 2A5 standard, the outer steel plate of the turret structure of one turret is missing).

 

According to an article published in the International Symposium on Ballistics by a German scients working for the Franco-German Institute in Saint-Louis (which is focused on military research), special combinations of high-hardness steel plates (probably as DHS or THS) can reach a thickness efficiency of 1.8 compared to RHS. DHS can reach a thickness efficiency of 1.78 accoridng to Hazell's Armour. Jane's Defence Weekly reported during the 1990s (or at least it claimed to have reported), that the Leclerc (contemporary to the Leopard 2A4 with "D" tech armor and the Leopard 2A5) uses THS with a thickness efficiency of 1.81 as part of its armor array. However DHS and THS are very expensive.

Heavy metal alloys such as DU and WHA have also both shown a thickness efficiency larger than 1.

 

Another factor is that the LKE1 APFSDS was still in development, the performance figure is estimated based on the actual 120 mm DM43 that was IIRC type-qualified in 1994 or 1996 (this also is a nice way to see that the armor array was tested in the early 1990s).

 

14 hours ago, Scav said:

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. 

 

The Leopard 2A5 requires swapping out armor inserts aswell, while requiring a modification of the armor layout at the gunner's sight, new hooks for the add-on armor modules and hinges for the new mantlet armor modules, a modification of the gun (with different trunion), modifying the optical channels of the sights and numerous changes not related to armor protection.

 

[Zadlo]

4 hours ago, SH_MM said:

(for example the company Ingenieurbüro Deisenroth stated in an article about the reveal of the Leopard 2 Evolution upgrade with AMAP armor, that the Leopard 2A4 used as basis for the demonstrator had originally a combat weight of 56.6 tonnes, which had to be lowered by removing the side skirts before the Evolution kit could be added to remain in the desired 60 tonnes weight limit).

 

According to Polish news agencies, Rheinmetall claims that the Leopard 2 turret with AMAP armor provides more protection than the Leopard 2A5 turret, but equal protection to the Leopard 2A7.

 

 

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

[Militarysta]

I will - Polish industry is sick. If somebody had claimed that Revolution AMAP armour + old special armour will give values beyond 2A5 and on par whit 2A7 but the same person/instytute haven't idea that armour pacage B and D is competly diffrent and in polish 2A4 is "B" it's mean that somebody shoud be layoff... :/

 

[Scav]

1 hour ago, SH_MM said:

Both Rolf Hilmes and Frank Lobitz specifically mention that the base armor of the Leopard 2A5 was replaced with new inserts in "D"  technology. During the Leopard 2A5 upgrade process, the turret structure of the Leopard 2A4 is cut open and new armor inserts in "D" technology are installed. For the last batch of Leopard 2A4 tanks Lobitz mention that the tank featured "improved armor protection" and at another place that it can be identified by the new light side skirts in "D" technology... adding one and one together and this leads to the last Leopard 2A4 featuring "D" technology armor.

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...

 

1 hour ago, SH_MM said:

According to Michael Scheibert, author for the (nowadays defunct) Waffen-Arsenal book series, the (first) Leopard 2A4 armor upgrade was weight neutral, i.e. there was no weight gain or loss (although I personally believe that there was some minor difference).

 

The 56.6 tonnes figure is rarely used, but it has appeared in a quite a few articles on the Leopard 2A4 and a number of press releases (for example the company Ingenieurbüro Deisenroth stated in an article about the reveal of the Leopard 2 Evolution upgrade with AMAP armor, that the Leopard 2A4 used as basis for the demonstrator had originally a combat weight of 56.6 tonnes, which had to be lowered by removing the side skirts before the Evolution kit could be added to remain in the desired 60 tonnes weight limit).

It isn't actually confirmed that this weight figure is related to the extremely rare Leopard 2A4 with "D" technology armor (only 75 made for the Bundeswehr of which only 1 still exists) or not - but unless the literature is wrong and the version with "C" armor is actually heavier than 55.15 tonnes, the 56.6 tonnes figure has to refer to the latest version by the method of elimination. In theory the Leopard 2A4 with "D" technology armor might also be heavier than 56.6 tonnes, I've never seen an actual weight value specifically mentioning that it belongs to the 75 tanks of the eight production batch.

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.

 

1 hour ago, SH_MM said:

The Soviets adopted new armor arrays (mainly for the hulls of their tanks) at a much steadier rate, e.g. the T-72B was built with three different armor arrays within a period of just 5 years. West-Germany adopted the new (and more protective) Leopard 1A3 turret just 13 months after the new turret for the Leopard 1A2 had entered production. The M1IP version of the Abrams entered production four years after the M1 Abrams, yet it featured improved armor and a longer turret. So three years for a new Leopard 2 armor package developed at the height of the Cold War doesn't seem implausible.

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.
 

2 hours ago, SH_MM said:

This image is from a set of documents delivered by Krauss-Maffei to Sweden and leaked as part of R. L.'s presentations.  It shows the references for the armor packages (although it doesn't mention wether this means that the armor protection is comparable to the Soviet tanks or meant to resist rounds fired by these Soviet tanks). The 3rd generation armor package (which would be "D" technology based on the German naming scheme) was adopted in 1991, yet the Leopard 2A5 entered service in 1995. It was meant to compare to the (armor or firepower of the) FST (Future Soviet Tank), which was expected to enter service in the 1990s and feature a next-generation gun (various different calibers including 125 mm, 130 mm, 135 mm and 152 mm have been mentioned in different articles over the years).

It appears that in fact both new armor packages for the Leopard 2A4 and the Leopard 2A5 were developed after the BMVg (German MoD) requested a higher level of protection back in 1984, which kickstarted the Leopard 2A5 development (a first prototype with add-on armor looking similar to the 2A5 being tested in 1986).

 

Please note that there are three versions of "D" technology armor (D-1, D-2 and D-3). The Leopard 2A4 could use "D-1" inserts, while the Leopard 2A5 made for Sweden could feature "D-2" or "D-3" inserts. I don't think that Krauss-Maffei would choose this "table format" for displaying armor packages, if the "D" technology armor was only available as add-on modules.

Note that the line "Pakete" (armor inserts) also contains fields for the three types of "D" generation armor. Also note that "Technologie-Kombination" means "technology combination" (implying that all types of add-on armor modules and base armor can be easily combined).

 

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.

Spoiler

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:

Spoiler

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.

 

2 hours ago, SH_MM said:

It is indeed a very odd situation, I can understand your skepticism. I probably also wouldn't believe anyone saying that he has a classified source showing that a tank had a much higher level of protection than other people consider plausible. I can only say what I have seen and what I've heard.

 

I don't think the M1A2 still has the same level of hull protection as the initial M1 Abrams. The British stated that the later has a protection was only 320 mm against kinetic energy penetrators (from the front?), while the M1A2 offered to Sweden reached 350 mm along the frontal arc (it could be a bit more directly at the frontal cavity, given that the weakest sectioon of the frontal arc is probably the side skirt area at 25-30°). The hull armor was upgraded with the variants M1A1/M1IP (there were at least weight demonstrators welded to the hull front of the M1E1). The hull armor of the Leopard 2 can be upgraded more easily, in the original models there even was a hatch to access the armor inserts (which was shut via bolts), only during the upgrade to the Leopard 2A4 this was shut by welding. In a Canadian Army maintenance facility, they have opened the hull armor cavity of a Leopard 2A4 with "B" armor package (the edges of the plates inside however are oddly soft compared to the rest of the photograph, they might have been added with photoshop):

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).

 

7 hours ago, SH_MM said:

As for the weight increase and the corresponding increase in armor protection, there are multiple factors to consider. First of all, there are differences between both tanks, that shouldn't be ignored. The Leopard 2A4's turret front is about 15% smaller than that of the M1A1 HA, thus for an equal increase in armor weight, the Leopard 2A4 would require only a weight gain of 2.55 tonnes. The 1.45 tonnes that the Leopard 2A4 with "D" technology might be heavier (assuming the 56.6 tonnes figure is correct) than the earlier variants seems to fall a bit short of that, but the question remains wether a M1A1 has the same amount of (turret) armor weight per volume as the Leopard 2A4 with "B" or "C" technology armor. Given the larger frontal profile and the extensive side armor, it seems possible that the Leopard 2A4 has actually denser armor to start with (at least this was the case when comparing the Leopard 2 to the M1 Abrams). Another factor is the side armor: the Leopard 2A4 from 1991 features new light side skirts made of high-hardness steel, which supposedly provide the same protection level at a slightly smaller thickness than the previous type. Also there are unconfirmed rumors about the side armor at the frontal section being different; some Danish soldier claimed that the Leopard 2A5DK has thicker steel side armor than the Strv 122, which at least partly might be confirmed by the fact, that the latter had a slightly lower protection level against RPGs hitting at 90° angle than the Leopard 2 KVT during the Swedish tests. Compared to the M1A2, the Leopard 2A4 has a much larger gun mantlet, which probably wouldn't be able to reach the same protection level (and probably would also have a much lower weight than the main armor).

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.

 

7 hours ago, SH_MM said:

The makers of the video game War Thunder measured the thickness of an early-model M1 Abrams using tape measures and an ultrasonic probe.They concluded that the backplate of the hull armor is 101 mm thick (excluding slope), which seems to be quite a bit. The Leopard 2 - at least on the turret - uses what seems to be a 40-60 mm thick backplate, thus more weight can be invested into special armor with a higher mass efficiency. Maybe the turret armor also follows this layout, at least the people from the War Thunder developer claim that the size of the special armor cavity is only 19.5 inches (I believe without slope). Assuming that the turret backplate is also 101 mm thick and knowing that the measured thickness of the turret frontplate was 38.1 mm, the total thickness of the M1 turret armor would be 634 mm or ~732 mm LOS from the front, which falls into the range of estimated armor thickness from various internet users.

 

It is worth noting that the M1A2 turret in Sweden provided 600 mm protection vs APFSDS rounds along the frontal arc, the armor tested in Germany was however simulating a hit directly from the front (otherwise the armor would be way too thick). So there still could be a ~10% difference in armor protection in favor of the M1A2 (esp. considering that the armor package with DU might be slightly better).

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:

Spoiler

 

7 hours ago, SH_MM said:

There is no doubt that the armor array survived a hit by a LKE1 APFSDS without being fully penetrated, which is why there are a few possible options:

1. The armor might not be identical to the one adopted on the Leopard 2A4 production model of 1991 - however the armor was tested before the DM43 APFSDS was type qualified (which IIRC happened in 1994 or 1996) and it was offered as an upgrade option for users of the Leopard 2A4 with "B" generation armor, so that doesn't seem to be the most likely option.
2. The Leopard 2A4 from 1991 might have a larger combat weight than assumed; it is a really rare variant and no user of the Leopard 2A4 seems to have ever upgraded their 2A4s to a version with "C" or "D" armor package (at least the side skirts have remained identical). 
3. The LKE1 APFSDS being a prototype mgith mean that it actually had a lower level of armor penetration than the DM43 APFSDS - but it probably was always superior to the DM33 APFSDS it was meant to replace (which apparently has ~480 mm at 2,000 m penetration).
4. The Leopard 2A4 armor from 1991 could be highly optimized against KE, potentially sacrificing relative protection vs HEAT. The rumored inclusion of tungsten and titanium would support this, as this would be similar to the DU armor of the M1A2 (at least the SEP features titanium within its armor array).

Yeah, those do seem likely or atleast possible.

 

7 hours ago, SH_MM said:

I dont think that is very accurate. I've seen a wide range of estimations for the M1A2's turret front (as low as "below 800 mm" and as high as 1,100 mm), yet no accurate measurements have ever been made. The M1A2 models use the same turret dimensions introduced with the M1IP in 1984; at this time 940 mm physical thickness would have been more than any other contemporary tank (T-72B, T-80U, Leopard 2 and Challenger 1 all having 800-870 mm physical thickness along the line-of-sight at most).

How did you estimate the thickness? Did you keep in mind that the slope of the turret cheeks is assymetrical (left turret cheek is sloped more than the right).

Here's one of the pictures he took from the front left corner of the armour, it's 733mm thick:

Spoiler

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.

 

Spoiler

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".

 

7 hours ago, SH_MM said:

Also don't forget that this is 600 mm along the frontal arc, so it is achieved by the unsloped armor package already. While the M1A2 Abrams has a combat weight of 62.5 tonnes, the armor weight was likely not increased over the M1A1 HA (at 61.8 tonnes; the M1A2 adds a lot of additional parts to the tank that might explain the weight difference); this is about 3 tonnes heavier than the M1A1 when both tanks are fitted with the T158 tracks.

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).

 

7 hours ago, SH_MM said:

There have been several statements from various sources hinting that there are more armor generations. When the Leopard 2A7 entered service with the German army, Jane's Defence Weekly stated that it is being protected by a "new generation" of armor in the turret and hull. According to Polish news agencies, Rheinmetall claims that the Leopard 2 turret with AMAP armor provides more protection than the Leopard 2A5 turret, but equal protection to the Leopard 2A7. There are also some mentions about certain exported tanks featuring "improved armor", although it is never mentioned what the point of reference is.

 

It seems rather reasonable to assume that after the "D" technology armor from 1991/1995, armor development didn't cease. The Leopard 2A7V prototype presented at Eurosatory 2016 for example features a different hull add-on armor kit compared to the Stridsvagn 122 (similar thickness, but the size and location of the mounting screws is different).

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.

 

7 hours ago, SH_MM said:

No, the entire armor array that stopped the LKE1 APFSDS was about 800 mm thick: 100 mm soft steel, 500 mm special armor, two layers of 100 mm soft steel. The APFSDS reached the third steel plate, so it defeated more than 700 mm armor.

 

The Leopard 2 is said to feature some extremely expensive steel types, which provide high levels of protection. For example according to the company that provides the very few cast steel elements for the Leopard 2 tank, the cast steel has a hardness of  350-380 HB on the initial model and 380-420 HB on the Leopard 2A4 and Leopard 2A5. The turret shell of the initial model was made of HFX 130 steel with an average hardess of 380 HB; it seems likely that the Leopard 2A4 tanks with "C" and "D" generation armor use different steel with a hardness of more than 400 HB (note that on the photograph showing the Leopard 2A4 turrets being upgraded to the 2A5 standard, the outer steel plate of the turret structure of one turret is missing).

 

According to an article published in the International Symposium on Ballistics by a German scients working for the Franco-German Institute in Saint-Louis (which is focused on military research), special combinations of high-hardness steel plates (probably as DHS or THS) can reach a thickness efficiency of 1.8 compared to RHS. DHS can reach a thickness efficiency of 1.78 accoridng to Hazell's Armour. Jane's Defence Weekly reported during the 1990s (or at least it claimed to have reported), that the Leclerc (contemporary to the Leopard 2A4 with "D" tech armor and the Leopard 2A5) uses THS with a thickness efficiency of 1.81 as part of its armor array. However DHS and THS are very expensive.

Heavy metal alloys such as DU and WHA have also both shown a thickness efficiency larger than 1.

 

Another factor is that the LKE1 APFSDS was still in development, the performance figure is estimated based on the actual 120 mm DM43 that was IIRC type-qualified in 1994 or 1996 (this also is a nice way to see that the armor array was tested in the early 1990s).

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.

 

7 hours ago, SH_MM said:

The Leopard 2A5 requires swapping out armor inserts aswell, while requiring a modification of the armor layout at the gunner's sight, new hooks for the add-on armor modules and hinges for the new mantlet armor modules, a modification of the gun (with different trunion), modifying the optical channels of the sights and numerous changes not related to armor protection.

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?

Spoiler

 

[Jägerlein]

4 hours ago, Scav said:

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...

I...doubt, thar Hilmes mixed up something in this matter. He did a bit more than "just writing about" the Leopard 2 upgrades.

[Scav]

10 hours ago, Jägerlein said:

I...doubt, thar Hilmes mixed up something in this matter. He did a bit more than "just writing about" the Leopard 2 upgrades.

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...

[SH_MM]

13 hours ago, Scav said:

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? 

There are several authors stating/implying this and at least one photograph of the Leopard 2 turrets without armor inserts during the upgrade process.

 

13 hours ago, Scav said:

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.

 

There are multiple possiblities how the protection might have been improved without increasing weight by a significant amount, also it is worth noting that we don't know the protection level against chemical energy rounds. Replacing steel with ceramics or using higher quality steel/DHS/THS could allow increasing the KE protection without affecting the weight, likewise altering the armor layout might help (using less NERA panels, but thicker ones with HHS capable of affecting APFSDS penetrators by a larger amount).

 

There is a Russian book claiming that West-Germany tested armor arrays during the 1970s, which were more comparable to the T-72B's internal NERA array (i.e. each sandwich plate consisted of a thicker frontplate made of steel with higher hardness followed by only a very thin rubber sheet and steel plate), which seems to be more capable of defeating APFSDS ammo. If the Leopard 2's "B" technology armor follows another layout (comparable to the M1 Abrams' BRL-1 composite), then switching to this array-type at the same weight might improve protection against KE (for potentially loosing a bit of CE protection).

 

13 hours ago, Scav said:

I'm still quite skeptical of a 2A4 with D tech, it seems like an awful lot of effort for only 75 tanks. 

 

Think about it this way: the tanks have already been ordered years ago, so if the manufacturer has already developed a new armor package that has finished testing, why not use it?

 

13 hours ago, Scav said:

True, but they were already in the process of developing the wedges and even had them by 1991

 

The wedge-shaped add-on armor was already fitted to the KVT (most likely not identical to what later went into production, but in an earlier form) in 1989, it might have been already available in 1988.

 

14 hours ago, Scav said:

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. 

  Reveal hidden contents

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? 

 

The TVM Min. and TVM Max. (which was used for some Swedish tests) were based on two Leopard 2A4 tanks from the eight batch and should therefore feature something like "D-1" base armor. All prototypes of the Leopard 2A5 had the "flat" side add-on armor modules, but all series production versions featured the wedge-shaped side armor. The add-on armor used on the Stridsvagn 122 seems to be identical to the one used on all series versions of the Leopard 2A5 and Leopard 2A6 tanks. That suggests the the changes to the add-on armor proposed by Sweden might have been adopted by all Leopard 2A5/2A6 users (Ingenieurbüro Deisenroth made apparently the add-on armor for all different 2A5 versions).

 

My understanding - or my theory - is that to keep the costs down Germany at the time of the Swedish trials was planning to upgrade the Leopard 2 with armor of the "B" generation by simply installing add-on armor (D-2), which Sweden considered to be insufficient, hence the proposed Swedish model featured a significantly higher level of protection. However after the Swedish trials (or during them), a number of factors (for example the decision to downsize the Bundeswehr and completely dissolve the Bundeswehrkommando Ost, the cancelation of the PzKpfW 2000 tank project, budget decisions, data of Soviet ammunition becoming available to NATO, appearance of the T-90, etc.) lead Germany to change the configuration "German model" of the Leopard 2A5, to also include "C" and "D-1" generation internal armor arrays. As a cost-cutting or weight-saving measure these changes to the configuration also required to drop the add-on armor modules for the turret roof and hull, whcih are part of the "German model" in the Swedish presentation by R L.

 

18 hours ago, Scav said:

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).

 

I agree with yellow most likely showing the Leopard 2 with "B" generation internal and "D-2" generation external armor.

 

The graph shows five different colors, but there are five different armor technologies with multiple possible combinations options. I think we can agree that the purple/pink graph shows the "B" armor package, while the red graph shows the "C" armor package; so if yellow shows "B" + "D-2", where is the graph is the "D-1" generation armor package and where is "D-3". Is the blue area the "D-3" armor kit ontop of the "B" armor package or the "D-1" or "D-2" add-on kit on the "C" generation base armor? And what does the green graph show, "D-1" base armor plus "D-2" or "D-3" add-ons or maybe the "B" or "C" oackge with the "D-3" add-on modules?

 

I think it seems clear that the Stridsvagn 122 is equal to the green graph based on the statement that it meet the required levels of protection at more than 70% of the places and that its hull armor managed to stop the 120 mm APFSDS round with 700 mm penetration. As I believe that the Stridsvagn 122 was made with the most advanced base armor available at the time (D-1), that would leaave the blue graph to show the "C" technology base armor + unknown add-on.

 

It seems you misunderstood me to some extend, I never said, that the Leopard 2A4 from 1991 with (what I believe would be) "D-1" armor would provide a higher level of protection than the KVT ("B" baseline protection + "D-2" modules); that alone has more than 700 mm equivalent turret armor protection against KE, which would be physically impossble with the Leopard 2A4's armor thickness. I'd expect it to fall between the yellow and the red graph.

 

20 hours ago, Scav said:

If so, would it be possible even plausible that it is indeed 800mm not taking into account angle because of a flat add-on ?

 

I don't think there was any add-on armor in these armor tests. It was one steel plate, one composite armor module, two steel plates and a few other layers. Unless the add-on armor was somehow capable of stopping the LKE1 APFSDS by itself, I would have expected there to be two composite armor modules (one for the add-on armor and one for the base armor) in such a test.

 

The Panzer 87 with Swiss 140 mm smoothbore gun is fitted with armor made for the Panzer 87 Werterhaltung program of 2006. Research and development for this armor was started by the company RUAG (owned by the Swiss government) in 1999. It has no relation to what Germany was offering in the 1990s and wouldn't have been tested against the LKE1 APFSDS.

 

20 hours ago, Scav said:

Here's one of the pictures he took from the front left corner of the armour, it's 733mm thick: 

  Reveal hidden contents

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. 

 

Thanks. These are great photographs, I've seen people making armor thickness estimates for the M1(A1/A2) Abrams for years, but nobody managed to make any actual photographs. Seems that I've understimated the armor thickness, but that was a result of the backplate. The measurement from the outside (where the backplate is not fully included) it shows a thickness of ~34-35 inches (860-890 mm).

 

So the M1A1/A2 have the same armor thickness at normal (no slope), that the original M1 Abrams had with slope.

 

20 hours ago, Scav said:

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). 

 

Well, the Swedes got 50% protection mostly as a result of weakspots (gun mantlet, turret ring, roof) and including the turret side armor. Only the turret frontal cheeks are meant to protect against APFSDS rounds with 600 mm penetration at the 30° arc. The turret side armor protects only against 480 mm KE along a 20° arc (although it seems that the whole crew compartment is located behind the frontal cheeks when seen at 20° angle from the turret centerline).

 

 

20 hours ago, Scav said:

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?

 

Patent DE3508053A1

 

[Scav]

4 hours ago, SH_MM said:

There are multiple possiblities how the protection might have been improved without increasing weight by a significant amount, also it is worth noting that we don't know the protection level against chemical energy rounds. Replacing steel with ceramics or using higher quality steel/DHS/THS could allow increasing the KE protection without affecting the weight, likewise altering the armor layout might help (using less NERA panels, but thicker ones with HHS capable of affecting APFSDS penetrators by a larger amount).

 

There is a Russian book claiming that West-Germany tested armor arrays during the 1970s, which were more comparable to the T-72B's internal NERA array (i.e. each sandwich plate consisted of a thicker frontplate made of steel with higher hardness followed by only a very thin rubber sheet and steel plate), which seems to be more capable of defeating APFSDS ammo. If the Leopard 2's "B" technology armor follows another layout (comparable to the M1 Abrams' BRL-1 composite), then switching to this array-type at the same weight might improve protection against KE (for potentially loosing a bit of CE protection).

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.

 

4 hours ago, SH_MM said:

Think about it this way: the tanks have already been ordered years ago, so if the manufacturer has already developed a new armor package that has finished testing, why not use it?

Fair point.

 

4 hours ago, SH_MM said:

The TVM Min. and TVM Max. (which was used for some Swedish tests) were based on two Leopard 2A4 tanks from the eight batch and should therefore feature something like "D-1" base armor.

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.

 

4 hours ago, SH_MM said:

ll prototypes of the Leopard 2A5 had the "flat" side add-on armor modules, but all series production versions featured the wedge-shaped side armor. The add-on armor used on the Stridsvagn 122 seems to be identical to the one used on all series versions of the Leopard 2A5 and Leopard 2A6 tanks. That suggests the the changes to the add-on armor proposed by Sweden might have been adopted by all Leopard 2A5/2A6 users (Ingenieurbüro Deisenroth made apparently the add-on armor for all different 2A5 versions).

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.

 

4 hours ago, SH_MM said:

My understanding - or my theory - is that to keep the costs down Germany at the time of the Swedish trials was planning to upgrade the Leopard 2 with armor of the "B" generation by simply installing add-on armor (D-2), which Sweden considered to be insufficient, hence the proposed Swedish model featured a significantly higher level of protection. However after the Swedish trials (or during them), a number of factors (for example the decision to downsize the Bundeswehr and completely dissolve the Bundeswehrkommando Ost, the cancelation of the PzKpfW 2000 tank project, budget decisions, data of Soviet ammunition becoming available to NATO, appearance of the T-90, etc.) lead Germany to change the configuration "German model" of the Leopard 2A5, to also include "C" and "D-1" generation internal armor arrays. As a cost-cutting or weight-saving measure these changes to the configuration also required to drop the add-on armor modules for the turret roof and hull, whcih are part of the "German model" in the Swedish presentation by R L.

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.

 

4 hours ago, SH_MM said:

The graph shows five different colors, but there are five different armor technologies with multiple possible combinations options. I think we can agree that the purple/pink graph shows the "B" armor package, while the red graph shows the "C" armor package; so if yellow shows "B" + "D-2", where is the graph is the "D-1" generation armor package and where is "D-3". Is the blue area the "D-3" armor kit ontop of the "B" armor package or the "D-1" or "D-2" add-on kit on the "C" generation base armor? And what does the green graph show, "D-1" base armor plus "D-2" or "D-3" add-ons or maybe the "B" or "C" oackge with the "D-3" add-on modules?

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.

 

4 hours ago, SH_MM said:

I think it seems clear that the Stridsvagn 122 is equal to the green graph based on the statement that it meet the required levels of protection at more than 70% of the places and that its hull armor managed to stop the 120 mm APFSDS round with 700 mm penetration. As I believe that the Stridsvagn 122 was made with the most advanced base armor available at the time (D-1), that would leaave the blue graph to show the "C" technology base armor + unknown add-on.

Possible as well.

 

4 hours ago, SH_MM said:

It seems you misunderstood me to some extend, I never said, that the Leopard 2A4 from 1991 with (what I believe would be) "D-1" armor would provide a higher level of protection than the KVT ("B" baseline protection + "D-2" modules); that alone has more than 700 mm equivalent turret armor protection against KE, which would be physically impossble with the Leopard 2A4's armor thickness. I'd expect it to fall between the yellow and the red graph.

Yeah, sorry, that is the most likely option which is why I find it suspicous to be missing from the graph.

 

4 hours ago, SH_MM said:

I don't think there was any add-on armor in these armor tests. It was one steel plate, one composite armor module, two steel plates and a few other layers. Unless the add-on armor was somehow capable of stopping the LKE1 APFSDS by itself, I would have expected there to be two composite armor modules (one for the add-on armor and one for the base armor) in such a test.

In that case I agree, probably wasn't an add-on.

 

4 hours ago, SH_MM said:

The Panzer 87 with Swiss 140 mm smoothbore gun is fitted with armor made for the Panzer 87 Werterhaltung program of 2006. Research and development for this armor was started by the company RUAG (owned by the Swiss government) in 1999. It has no relation to what Germany was offering in the 1990s and wouldn't have been tested against the LKE1 APFSDS.

ohhhh, thanks! 
I always wondered why it looked relatively modern (clean) without some kind of restoration having been done to it.

 

4 hours ago, SH_MM said:

Thanks. These are great photographs, I've seen people making armor thickness estimates for the M1(A1/A2) Abrams for years, but nobody managed to make any actual photographs. Seems that I've understimated the armor thickness, but that was a result of the backplate. The measurement from the outside (where the backplate is not fully included) it shows a thickness of ~34-35 inches (860-890 mm).

 

So the M1A1/A2 have the same armor thickness at normal (no slope), that the original M1 Abrams had with slope.

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.

 

4 hours ago, SH_MM said:

Well, the Swedes got 50% protection mostly as a result of weakspots (gun mantlet, turret ring, roof) and including the turret side armor.

True, side effect (probably intended) of their simulation I guess.

 

4 hours ago, SH_MM said:

Only the turret frontal cheeks are meant to protect against APFSDS rounds with 600 mm penetration at the 30° arc. The turret side armor protects only against 480 mm KE along a 20° arc (although it seems that the whole crew compartment is located behind the frontal cheeks when seen at 20° angle from the turret centerline).

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!

 

4 hours ago, SH_MM said:

Patent DE3508053A1

Thanks!
I have been looking on that site but clearly my search skillz weren't quite up to par .

[SH_MM]

11 hours ago, Scav said:

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. 

 

West-Germany got access to Burlington armor beginning in 1970 (selected scientists) and started developing a common MBT with the UK between 1972 and 1977. When the West-Germany first announced that they had developed a composite armor package for the Leopard 2, the UK assumed that it was heavily based on the knowledge and technology used for Burlington, acquired during the early 1970s.

 

However West-Germany claimed that this armor was a local development, probably based on the fact that Dr. Manfred Held (the inventor of modern ERA, as the Soviets ceased ERA research at the end of the 1950s) patented NERA in 1973.

 

 

11 hours ago, Scav said:

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.

 

The Leopard 2 TVM Max. was tested in Sweden, which was based on the chassis number 11156 and therefore belonged to the last production batch (with what I believe to be "D-1" type armor). As the TVM Max. returned to Germany after the Swedish trials, it seems that Sweden only tested armor arrays representing the corresponding Leopard 2 tanks rather than firing at real tanks - the same happened with the M1A2 Abrams. Reading through Richard Lindström's article and a few German sources, it seems that only a single Leopard 2 was send to Sweden. Therefore the tested armor arrays and thte actual tank tested by Sweden might be independent from each other.

 

I don't think that "German model" and "Swedish model" actually refers to "tank that Germany wants to sell to Sweden" and "tank that Sweden wants to buy", but rather to "Leopard 2 version currently considered for adoption by Germany" and "Leopard 2 version suggested by Krauss-Maffei for Sweden".

 

11 hours ago, Scav said:

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). 

 

This seems to be a case of common excuses from people pretending that their own military always makes the right decisions and has infinite budget, while all others are wrong. The increase in profile is irrelevant, given that there is no protected volume behind the roof modules in the horizontal plane. Given that the PERI was raised on the Strv 122 + TVMs with roof armor, there also wouldn't be a negative difference in terrms of situational awareness. The Panzerhaubitze 2000 has received similar thick roof armor without issues, the Puma also features some (albeit thinner).

The roof armor would likely be included in a 140 mm variant projected during the 1990s to arrive in active troop service by 2008, but canceled when the NGP project was started.

 

12 hours ago, Scav said:

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. 

 

I don't think it is reasonable to argue with LOS efficiency in case of the wedge-shaped add-on armor. Unlike the base armor, the majority of its volume is hollow, the actual LOS thickness is variable depending on impact location (the maximum LOS is only reached at the center; hitting above or below it, the overall LOS will decrease massively). In terms of function, the armor is ought to be much more comparable to heavy ERA, i.e. weakening the incoming projectile in such a way that the base armor can defeat it. 

 

There are several reasons why I don't agree with your theory.

• I don't think there is actually any actual proof that there were different add-on modules being tested on the Leopard 2 Improved protoypes. While the table format chosen by KMW suggests there might have been more than just one type of add-on armor, it also includes slots/positions for "B" and "C" technology Vorsatzmodule. External the only differences between the Leopard 2 Improved prototypes and the series production models is the shape of the side add-on armor modules. which have become thinner (!) on the series production version. I'd argue that these changes could have been made to reduce weight and do not indicate any change in the composition or effectiveness of the frontal add-on armor modules.
• For the "German model"/KVT, the "B" armor package improves protection from ~450 mm vs KE at the left turret front to 862 mm vs KE. If we assume the same relative increase at 30°, the protection level is only at best 668 mm vs KE (the Swedish documents noted that the left turret cheeck of the "German model" of the Leopard 2 Improved is only capable of stopping an APFSDS with 700 mm penetration into steel at direct impact from the front) - please note that the efficiency of the add-on NERA probably decreases when hit from an angle, because the LOS thickness of the NERA plates is reduced, the thickness of the empty space is reduced and (most importantly) the lower angle means less material is forced into the path of the penetrator. That's why 862 mm vs KE from the front could be as low as 600 mm vs KE at 30°. The "Swedish model" is capable of providing 720 mm vs KE at 30° impact angle.
• Comparing the right turret cheek armor at 0° might be misleading, because their was a new armor block added when the EMES-15 sight was raised. But again the "Swedish model" is a lot better protected against attacks from an angle (810 mm vs KE at 30° compared to 758 mm vs KE at 20°).
• According to Rolf Hilmes' 2007 book "Kampfpanzer heute und morgen: Konzepte - Systeme - Technologien", the Stridsvagn 122 has a higher level of ballistic protection than the German Leopard 2A5 while mentioning the increased roof and hull armor as separate points.
• Weight. The Leopard 2A4 with "B" generation armor weighs just 55.15 tonnes. The weight of each frontal add-on armor module for the turret is about 500 kg as revealed by the Dutch army. Estimated weight of boith turret side add-on armor modules is less than 500 kg combined (they cover a similar area as the frontal modules, but are made of a single NERA layer instead of 2-3 and are less sloped). Given a combat weight of 62.500 kg, the weight of the hull add-on armor and roof armor would be about 5.85 tonnes. Comparing the weight differences of several other versions suggest that is incorrect (for example the Leopard 2A5DK and Leopard 2A7V feature hull add-on modules, but no roof armor, giving us an idea about the relative weight of both armor systems).
• The Stridsvagn 122 was used as demonstrator by KMW in the Greek tests, because it was considered superior to the German tank.

12 hours ago, Scav said:

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. 

 

If "D-1" would refer to the additional roof armor, why wouldn't it look like this for the "German model"/KVT? Given that the tank featured roof add-on armor...

 

Also the term "Vorsatz-Modul" strictly translated would be "module that sits in the front", not "on top" as roof-mounted armor would do. You can try to contact Lindström, but given that he removed the original files and photographs from the armor tests from his website, I don't think he is allowed to answer your questions.

 

[Scav]

38 minutes ago, SH_MM said:

West-Germany got access to Burlington armor beginning in 1970 (selected scientists) and started developing a common MBT with the UK between 1972 and 1977. When the West-Germany first announced that they had developed a composite armor package for the Leopard 2, the UK assumed that it was heavily based on the knowledge and technology used for Burlington, acquired during the early 1970s.

 

However West-Germany claimed that this armor was a local development, probably based on the fact that Dr. Manfred Held (the inventor of modern ERA, as the Soviets ceased ERA research at the end of the 1950s) patented NERA in 1973.

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.

 

39 minutes ago, SH_MM said:

The Leopard 2 TVM Max. was tested in Sweden, which was based on the chassis number 11156 and therefore belonged to the last production batch (with what I believe to be "D-1" type armor). As the TVM Max. returned to Germany after the Swedish trials, it seems that Sweden only tested armor arrays representing the corresponding Leopard 2 tanks rather than firing at real tanks - the same happened with the M1A2 Abrams. Reading through Richard Lindström's article and a few German sources, it seems that only a single Leopard 2 was send to Sweden. Therefore the tested armor arrays and thte actual tank tested by Sweden might be independent from each other.

I drew the same conclusion, though I don't know much about the TVMs.

 

40 minutes ago, SH_MM said:

I don't think that "German model" and "Swedish model" actually refers to "tank that Germany wants to sell to Sweden" and "tank that Sweden wants to buy", but rather to "Leopard 2 version currently considered for adoption by Germany" and "Leopard 2 version suggested by Krauss-Maffei for Sweden".

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.

 

41 minutes ago, SH_MM said:

This seems to be a case of common excuses from people pretending that their own military always makes the right decisions and has infinite budget, while all others are wrong.

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.

 

43 minutes ago, SH_MM said:

The increase in profile is irrelevant, given that there is no protected volume behind the roof modules in the horizontal plane.

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.

 

46 minutes ago, SH_MM said:

The Panzerhaubitze 2000 has received similar thick roof armor without issues, the Puma also features some (albeit thinner).

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.

 

48 minutes ago, SH_MM said:

I don't think it is reasonable to argue with LOS efficiency in case of the wedge-shaped add-on armor. Unlike the base armor, the majority of its volume is hollow, the actual LOS thickness is variable depending on impact location (the maximum LOS is only reached at the center; hitting above or below it, the overall LOS will decrease massively). In terms of function, the armor is ought to be much more comparable to heavy ERA, i.e. weakening the incoming projectile in such a way that the base armor can defeat it. 

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.

 

57 minutes ago, SH_MM said:

I don't think there is actually any actual proof that there were different add-on modules being tested on the Leopard 2 Improved protoypes. While the table format chosen by KMW suggests there might have been more than just one type of add-on armor, it also includes slots/positions for "B" and "C" technology Vorsatzmodule. External the only differences between the Leopard 2 Improved prototypes and the series production models is the shape of the side add-on armor modules. which have become thinner (!) on the series production version. I'd argue that these changes could have been made to reduce weight and do not indicate any change in the composition or effectiveness of the frontal add-on armor modules.

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 :).

 

1 hour ago, SH_MM said:

For the "German model"/KVT, the "B" armor package improves protection from ~450 mm vs KE at the left turret front to 862 mm vs KE. If we assume the same relative increase at 30°, the protection level is only at best 668 mm vs KE (the Swedish documents noted that the left turret cheeck of the "German model" of the Leopard 2 Improved is only capable of stopping an APFSDS with 700 mm penetration into steel at direct impact from the front) - please note that the efficiency of the add-on NERA probably decreases when hit from an angle, because the LOS thickness of the NERA plates is reduced, the thickness of the empty space is reduced and (most importantly) the lower angle means less material is forced into the path of the penetrator. That's why 862 mm vs KE from the front could be as low as 600 mm vs KE at 30°. The "Swedish model" is capable of providing 720 mm vs KE at 30° impact angle.

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.

 

1 hour ago, SH_MM said:

According to Rolf Hilmes' 2007 book "Kampfpanzer heute und morgen: Konzepte - Systeme - Technologien", the Stridsvagn 122 has a higher level of ballistic protection than the German Leopard 2A5 while mentioning the increased roof and hull armor as separate points.

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.

 

1 hour ago, SH_MM said:

Weight. The Leopard 2A4 with "B" generation armor weighs just 55.15 tonnes. The weight of each frontal add-on armor module for the turret is about 500 kg as revealed by the Dutch army. Estimated weight of boith turret side add-on armor modules is less than 500 kg combined (they cover a similar area as the frontal modules, but are made of a single NERA layer instead of 2-3 and are less sloped). Given a combat weight of 62.500 kg, the weight of the hull add-on armor and roof armor would be about 5.85 tonnes. Comparing the weight differences of several other versions suggest that is incorrect (for example the Leopard 2A5DK and Leopard 2A7V feature hull add-on modules, but no roof armor, giving us an idea about the relative weight of both armor systems).

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.

 

1 hour ago, SH_MM said:

The Stridsvagn 122 was used as demonstrator by KMW in the Greek tests, because it was considered superior to the German tank.

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.

 

1 hour ago, SH_MM said:

If "D-1" would refer to the additional roof armor, why wouldn't it look like this for the "German model"/KVT? Given that the tank featured roof add-on armor...

Good point, I don't know, perhaps this was for an earlier version, though that doesn't seem likely.

 

1 hour ago, SH_MM said:

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?

 

1 hour ago, SH_MM said:

Also the term "Vorsatz-Modul" strictly translated would be "module that sits in the front", not "on top" as roof-mounted armor would do. You can try to contact Lindström, but given that he removed the original files and photographs from the armor tests from his website, I don't think he is allowed to answer your questions.

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!

 

[SH_MM]

4 hours ago, Scav said:

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.

 

Unless you have seen different documents than me, the statement comes from a document written in 1970, when the Keiler/Leopard 2 was expected to enter service before 1975 (and as a matter of fact was still using simple space armor, using MLC50 as upper weight limit). They stated that it would be possible to modify the design (to include Burlington armor) and put it into production by 1975.

 

5 hours ago, Scav said:

Doesn't the commander actually sit higher though?

 

No, the seat is located in the same space. The additional volume above it is completely occupied by the armored hatch

5 hours ago, Scav said:

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.

 

I believe it is impossible to achieve the protection level of the Swedish tank just by adding the Leopard 2A5 wedge armor to a Leopard 2A4 with "B" generation armor. It just isn't very thick, IBD Deisenroth tested a double-layered NERA array in the 1990s, which consisted of two sandwich plates (10.5 mm semi-hardened steel + 7-8 mm special material + 10.5 mm semi-hardened) - this might be related to the wedges, the overall thickness considering the slope (65°) seems to match the Leopard 2A5's wedge armor. Such an armor array would not be suitable for providing 400-500 mm steel equivalent protection (given that the Swedish MBT reaches 800-900 mm vs KE from the front).

 

The third NERA layer doesn't actually cover a lot of frontal surface and might be adopted to improve the protection of the mantlet along the frontal arc.

 

5 hours ago, Scav said:

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.

 

Still the slides say that the Leopard 2 "Swedish model" has at least 700 mm protection along the frontal 30° at the left cheek compared to 0° for 700 mm protection for the left cheek of the "German model".

 

5 hours ago, Scav said:

Interesting, he didn't mean it as an overlapping statement?

 

He also mentions that according to his understanding the Stridsvagn 122 uses titanium armor (Ti-6Al-4V) and that the high protection requirements meant that turret and hull had to be newly built, because it wasn't possible/practical to convert existing Leopard 2s to this configuration. 

 

5 hours ago, Scav said:

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 don't know what you mean with "front hull roof was increased". The driver's hatch was altered, the side skirts aren't actually heavier given that the frontal elements are fitted to the Leopard 2A4 with "C" generation armor (and armor changes to this variant supposedly was weight neutral compared to the earlier model) and the rear section of the new skirts adopted on the 1991 model of the Leopard 2A4 has been described as "lighter" [compared to earlier variants].

 

The weight of a Dutch Leopard 2A6 turret is something like 19.75 tonnes compared to 15.5 tonnes for the original 2A4 (B) version.

 

5 hours ago, Scav said:

AFAIK the Strv 122 also incorporates the mine protection, which is probably around 1-2t. 

 

The Stridsvagn 122 doesn't feature a mine protection. The Strv 122B (4 Strv 122 tanks converted) features the same mine protection kit as the Leopard 2A6M, the combat weight is above 64 tonnes.

 

5 hours ago, Scav said:

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. 

 

If they decided to use a German army version, yes. But the KVT/IVT and TVM Max. were all available with IFIS (C4I) and armor modules covering the roof and hull aswell.

 

5 hours ago, Scav said:

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?

 

For the Leopard 2 with "B" generation armor, there wasn't a combination, because the base armor wasn't combined with anything. The Leopard 2 "German model" with "B" base armor (located in column 1) and "D-2" add-on modules (located in column 4) has the technology combination 5, which is why I think that it is the sum of the columns numbers (1+4).

 

[Scav]

1 minute ago, SH_MM said:

Unless you have seen different documents than me, the statement comes from a document written in 1970, when the Keiler/Leopard 2 was expected to enter service before 1975 (and as a matter of fact was still using simple space armor, using MLC50 as upper weight limit). They stated that it would be possible to modify the design (to include Burlington armor) and put it into production by 1975.

Might've even been a book for all I remember, it's not that easy to find.

 

20 minutes ago, SH_MM said:

No, the seat is located in the same space. The additional volume above it is completely occupied by the armored hatch

Oh interesting, I'd imagine that they did something so the commander can more easily reach the hatch?

 

23 minutes ago, SH_MM said:

I believe it is impossible to achieve the protection level of the Swedish tank just by adding the Leopard 2A5 wedge armor to a Leopard 2A4 with "B" generation armor. It just isn't very thick, IBD Deisenroth tested a double-layered NERA array in the 1990s, which consisted of two sandwich plates (10.5 mm semi-hardened steel + 7-8 mm special material + 10.5 mm semi-hardened) - this might be related to the wedges, the overall thickness considering the slope (65°) seems to match the Leopard 2A5's wedge armor. Such an armor array would not be suitable for providing 400-500 mm steel equivalent protection (given that the Swedish MBT reaches 800-900 mm vs KE from the front).

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:

Spoiler

It's pretty hard to tell how thick it is, I think it says 26 or 28mm.

Might be related.

 

26 minutes ago, SH_MM said:

The third NERA layer doesn't actually cover a lot of frontal surface and might be adopted to improve the protection of the mantlet along the frontal arc.

I agree.

 

27 minutes ago, SH_MM said:

Still the slides say that the Leopard 2 "Swedish model" has at least 700 mm protection along the frontal 30° at the left cheek compared to 0° for 700 mm protection for the left cheek of the "German model".

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.

 

28 minutes ago, SH_MM said:

He also mentions that according to his understanding the Stridsvagn 122 uses titanium armor (Ti-6Al-4V) and that the high protection requirements meant that turret and hull had to be newly built, because it wasn't possible/practical to convert existing Leopard 2s to this configuration. 

Thanks, I really need that book it seems, there's a lot of info in there I assume.

 

29 minutes ago, SH_MM said:

I don't know what you mean with "front hull roof was increased".

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.

 

32 minutes ago, SH_MM said:

The weight of a Dutch Leopard 2A6 turret is something like 19.75 tonnes compared to 15.5 tonnes for the original 2A4 (B) version.

So most of the weight changes was turret?
That would definitely indicate more changes than I thought.

 

33 minutes ago, SH_MM said:

the side skirts aren't actually heavier given that the frontal elements are fitted to the Leopard 2A4 with "C" generation armor (and armor changes to this variant supposedly was weight neutral compared to the earlier model) and the rear section of the new skirts adopted on the 1991 model of the Leopard 2A4 has been described as "lighter" [compared to earlier variants].

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.

 

35 minutes ago, SH_MM said:

The Stridsvagn 122 doesn't feature a mine protection. The Strv 122B (4 Strv 122 tanks converted) features the same mine protection kit as the Leopard 2A6M, the combat weight is above 64 tonnes.

I was under the impression that the weight was 62.5 for the 122B, sorry.

 

36 minutes ago, SH_MM said:

If they decided to use a German army version, yes. But the KVT/IVT and TVM Max. were all available with IFIS (C4I) and armor modules covering the roof and hull aswell.

Yeah I assumed the choice was between German army version and Swedish Strv 122.

 

38 minutes ago, SH_MM said:

For the Leopard 2 with "B" generation armor, there wasn't a combination, because the base armor wasn't combined with anything. The Leopard 2 "German model" with "B" base armor (located in column 1) and "D-2" add-on modules (located in column 4) has the technology combination 5, which is why I think that it is the sum of the columns numbers (1+4).

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....

 

[SH_MM]

11 hours ago, Scav said:

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:

  Reveal hidden contents

It's pretty hard to tell how thick it is, I think it says 26 or 28mm. 

Might be related

 

Yes, I was talking about that. The picture is showing a snipplet from a research paper that involves both Deisenroth and Condat Scheyern,  two companies involved with the Leopard 2A5's survivability upgrade. The array consists of two sandwich plates, each formed by two steel plates with 10.5 mm steel with yield strength of 1,200 MPa and either seven or eight milimetres thick layer of elastic material (five different materials were tested). Both sandwich plates are spaced 30 mm apart, the whole array is sloped att 65°. The overall thickness of this array seems to be identical to the thickness of the two frontal NERA plates (and empty space) at the front of the Leopard 2A5's wedge-shaped add-on armor modules.

 

11 hours ago, Scav said:

Thanks, I really need that book it seems, there's a lot of info in there I assume.

 

Not regarding the armor of the Leopard 2/Stridsvagn aside of (incorrect) internet estimates for the Leopard 2A0 armor protection.

 

11 hours ago, Scav said:

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.

 

That is probably a mistake caused by the hatch sliding mechanism sitting in front of the hatch. On the Leopard 2 up to (and including) the 2A4 variant, the hatch swivels. The new sliding hatch adopted with the Leopard 2A5 requires a different mechanism, which is mounted in front of the driver's hatch (and also the hatch itself seems to have become a bit thicker).

 

 

So measuring what is in front of the hatch doesn't equal the thickness of the hull armor. On the Dutch and German Leopard 2A5, the hull armor wasn't changed compared to the "C" and/or "D-1" generation original layouts.

 

11 hours ago, Scav said:

So most of the weight changes was turret?

 

The Leopard 2A6NL is - like the Germany Leopard 2A5 and Leopard 2A6 - built to the Mannheimer configuration, hence the hull did not receive an add-on armor module and is largely unchanged (aside of the new hatch and rear drive camera) compared to the later batches of the Leopard 2A4.

 

 

The Dutch tanks originally had "B" generation main armor, but apparently this was changed (the heavy skirts of the "C" generation were adopted, so base armor might also have been altered). The turrets likely have "D" generation main armor like the German model.

 

11 hours ago, Scav said:

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....

 

I don't think they offered all combinations of armor, that clearly wouldn't make sense.

 

The LOS thickness of the base armor on the right thickness is higher, once an armor block was added in front of the optic. According to the analysis from Laviduce, the right turret cheek of the Leopard 2 with "B" generation armor already offers a higher level of protection than the left cheek, which makes sense (below the optic, the LOS is 1,100-1,200 mm - including an empty space, but that would also improve protection a bit).

 

Edit: Seeing you have posted a measurement of the M1A2's hull armor on another forum, it seems confirmed that the LOS thickness of the M1IP/M1A1's hull was increased compared to the M1 Abrams measured by the War Thunder developers.

[Scav]

2 hours ago, SH_MM said:

Not regarding the armor of the Leopard 2/Stridsvagn aside of (incorrect) internet estimates for the Leopard 2A0 armor protection.

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.

 

3 hours ago, SH_MM said:

That is probably a mistake caused by the hatch sliding mechanism sitting in front of the hatch. On the Leopard 2 up to (and including) the 2A4 variant, the hatch swivels. The new sliding hatch adopted with the Leopard 2A5 requires a different mechanism, which is mounted in front of the driver's hatch (and also the hatch itself seems to have become a bit thicker).

Yeah, it's not easy to see the thickness of either without having a measuring tape.

It was just a rough guess.

 

3 hours ago, SH_MM said:

The Leopard 2A6NL is - like the Germany Leopard 2A5 and Leopard 2A6 - built to the Mannheimer configuration, hence the hull did not receive an add-on armor module and is largely unchanged (aside of the new hatch and rear drive camera) compared to the later batches of the Leopard 2A4.

Yeah, I expected some minor changes in the hull and I didn't know C tech was weight neutral.

 

3 hours ago, SH_MM said:

The Dutch tanks originally had "B" generation main armor, but apparently this was changed (the heavy skirts of the "C" generation were adopted, so base armor might also have been altered). The turrets likely have "D" generation main armor like the German model.

So more or less a complete overhaul of the armour?

 

3 hours ago, SH_MM said:

I don't think they offered all combinations of armor, that clearly wouldn't make sense.

I agree, that's why I initally thought D tech wasn't a main armour technology but small things like skirts and add-ons.

 

3 hours ago, SH_MM said:

The LOS thickness of the base armor on the right thickness is higher, once an armor block was added in front of the optic. According to the analysis from Laviduce, the right turret cheek of the Leopard 2 with "B" generation armor already offers a higher level of protection than the left cheek, which makes sense (below the optic, the LOS is 1,100-1,200 mm - including an empty space, but that would also improve protection a bit).

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.....

 

 

[CrappyHead]

 

indonesian Leopard 2RI , Leo 2a4 and marder IVF  after training exercise 

[Scav]

@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:

Spoiler

 

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?

[Voodoo]

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..

[Scav]

2 hours ago, Voodoo said:

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."

Thanks!

So I assume he doens't talk about wether or not the base armour was changed in type?

 

2 hours ago, Voodoo said:

Sorry for barging in to your conversation and if not understanding your question..

This was the information I was looking for, thanks!

[Voodoo]

On 12/8/2018 at 2:28 PM, Scav said:

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!

 

He does not go into detail about the D-technology, I'm afraid. The only thing being mentioned about armour, is about the sixth/seventh batch. "From the 97th vehicle onwards, a modified version of the spaced multilayered armour(Beulblechpanzerung), externally not visible, was installed. (KMW)"

[Scav]

2 hours ago, Voodoo said:

He does not go into detail about the D-technology, I'm afraid. The only thing being mentioned about armour, is about the sixth/seventh batch. "From the 97th vehicle onwards, a modified version of the spaced multilayered armour(Beulblechpanzerung), externally not visible, was installed. (KMW)"

That would refer to C tech as far as I know.

Still, good info, don't find much of that.

[SH_MM]

On 12/2/2018 at 3:14 PM, Scav said:

So more or less a complete overhaul of the armour? 

 

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.).

 

On 12/2/2018 at 3:14 PM, Scav said:

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.

 

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:

 

 

On 12/7/2018 at 9:43 PM, Scav said:

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: 

  Reveal hidden contents

  

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....

 

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.

 

On 12/7/2018 at 9:43 PM, Scav said:

Anyway, would you mind sharing what Rolf Hilmes or other authors have to say about this?

 

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.

 

[Scav]

2 hours ago, SH_MM said:

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.

 

So I should assume a higher protection under the EMES-15.

 

2 hours ago, SH_MM said:

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.

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).

 

2 hours ago, SH_MM said:

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.

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.

 

2 hours ago, SH_MM said:

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:

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.

 

3 hours ago, SH_MM said:

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 think he's trying to say this:

Quote

Compared to the 6th and 7th batches the vehicles of the 8th batch now also have light skirts in D technology.

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.

 

3 hours ago, SH_MM said:

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...

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.

 

3 hours ago, SH_MM said:

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.

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.