Contemporary Western Tank Rumble!

[Olds]

 

Quote

The document actually says that the MBT-80 has higher protection against ATGMs and RPGs (or rather: it has a lower probability of being destroyed by ATGMs/RPGs) than the Abrams, as long as the hull is hidden behind terrain.

The PK might be dubious as it depends on how they weighted the attack angles, etc. So I lean toward the simpler formulation: "MBT80 is better protected against KE attack than XM1 whilst XM1 has better HEAT protection than MBT80".

 

Quote

The Chieftain Mk 5/2 project from 1970 already was designed to resist large calibre shaped charge warheads (a 5.0 inch warhead and a 6.0 inch warhead with 60° cone angle), that were capable of penetrating 23 and 28 inches of steel armor (584 and 711 mm) which is more than what the XM1 Abrams was designed to resist.

The UK experimented pretty wildly with protection levels in the early Chobham days (mid 60's-70's). They ended up shifting--increasingly and quite rightly--toward KE protection, and perhaps the added weight there diminished their fervor for high CE. The M1 did indeed end up with a weirdly high CE given its spec. But it appears that all the way through to the M1A1, the US was laboring under the assumption that tanks needed more CE protection... MOAR!

 

Quote

 

As pointed out earlier in this topic, the UK tested the early production model of the Leopard 2 with the initial armor package. Based on the leaked data and some reasonable assumptions (i.e. that the largest physicial thickness provides most protection), it would provide about as much protection as 430 mm armor steel at the turret front.

... The Leopard 2A4 production model from 1988 seems to have armor protection comparable to 540-550 mm steel at the turret front and about 425 mm at the hull front, which is roughly comparable to the T-72B and overall superior to the Chieftain with Stillbrew armor.

 

Hmm... these seem like excessively high numbers, especially for the initial armor package. I think the official-ish estimates of the Leo-2 initial armor spec suggests lower numbers:

• It was designed for a roughly similar spec as the XM1, whose final numbers met that spec. The US found the Leo-2 armor inferior--and possibly not just in coverage.
• The 1978 UK chart--accurate in other respects--gives the Leo-2 a mere 300 'frontal protection.' Could it have ended up a tad higher? Sure, but not by 100+mm I'd say.
• It'd be hard to interpret the Krapke 1986(?) chart as approaching those high values--row 7 is especially damning. A value in the low 300's would fit however.
• The Swedish "Leopard 2A4 vs Leopard 2 'Improved' " chart likewise supports low numbers. (Whatever the tank on the left is, it'd be hard to describe its overall protection level as much more than 300, and that middle graph suggests there was a subsequent averaging 450 tops). I'd say "wimpy tank" fits with original armor and "next wimpiest" tank fits with the first armor upgrade. If "wimpy tank" was the Leo-2A4 armor upgrade, then even my estimates are too high!
• Even Rolf Hilmes slippery slide refers to the updated (turret armor) package I think, not the original armor (obviously there was no Leo2A4 in 1979).

Long story short: Leo2A0 <=350 KE! Leo2A4 <=450 KE! But don't take my word for it, even the Germans knew the 80's Leo-2 and everything about it was overrated.  OK, that was going too far! Nonetheless, I do get the feeling that what fragmentary statements we have (these and a few others) correlate more probably with the low values rather than the high ones.

 

I'm only speaking of the original armor and the first upgrade. Speaking of which, was the first armor upgrade to the turret only--so the hull stayed the same?

 

P.S. FWIW, my impression is that initial German "Chobham"--such as it was--was inferior to contemporary UK & US work. It seems to me the US got the better of the armor technology deals, and the UK was more cautious in sharing with Germany during the FMBT collaboration.

 

 

 

[SH_MM]

2 hours ago, Olds said:

The UK experimented pretty wildly with protection levels in the early Chobham days (mid 60's-70's). They ended up shifting--increasingly and quite rightly--toward KE protection, and perhaps the added weight there diminished their fervor for high CE. The M1 did indeed end up with a weirdly high CE given its spec. But it appears that all the way through to the M1A1, the US was laboring under the assumption that tanks needed more CE protection... MOAR!

 

There were improved armor arrays being developed during the 1970s, which improved protection against both KE and HEAT compared to previous prototypes. The canceled Chobham-armor upgrade for the Chieftain tank also would have met the US requirements in many areas (and it had better side armor as demanded).

 

The British tanks had a higher level of protection, because more weight was used for the armor. The Chieftain Mk 5/2 would have had a greater weight as the M1 Abrams, but was designed to feature a weight-efficient aluminium construction - that means a lot more weight could be used for armor. The MBT-80 was heavier than the Abrams, but was designed to use a hybrid construction (steel and aluminium), so again more weight could be used for armor. The Chieftain with similar construction technology as the Abrams weighed quite a few tons more - more weight was available for the armor.

 

2 hours ago, Olds said:

Hmm... these seem like excessively high numbers, especially for the initial armor package. I think the official-ish estimates of the Leo-2 initial armor spec suggests lower numbers:

 

...

 

The Swedish "Leopard 2A4 vs Leopard 2 'Improved' " chart likewise supports low numbers. (Whatever the tank on the left is, it'd be hard to describe its overall protection level as much more than 300, and that middle graph suggests there was a subsequent averaging 450 tops). I'd say "wimpy tank" fits with original armor and "next wimpiest" tank fits with the first armor upgrade. If "wimpy tank" was the Leo-2A4 armor upgrade, then even my estimates are too high! 

 

I think you might be misreading the graph. It shows the protection level in relation to the percentage of the surface area that achieves such a protection level. If you take a look at a photograph of a Leopard 2 taken from the front or at a scale drawing from the front and then take a look at the armored surface area excluding the tracks, you'll get 100% of the protected area. At 50% of this area, the very first production model of the Leopard 2 achieves a protection level equivalent to 300 mm steel armor or more against KE penetrators. Now given that the we know the armor thickness of the Leopard 2 - it has been measured, we know that at certain areas physically cannot reach a protection level of 300 mm or more against KE. We also know where the armor is thicker and thus most likely reaches more than 300 mm protection against KE. @Laviduce has done a lot of work on this topic, you can find it here and in the Leopard 2 thread.

 

If you take a look at the turret front - where the Leopard 2 has the thickest armor - you'll see that it covers about 18% of the armored surface area. Reading the graph at 18% leads to a protection level of about ~430 mm steel-equivalent protection against KE rounds.

 

2 hours ago, Olds said:

It was designed for a roughly similar spec as the XM1, whose final numbers met that spec. The US found the Leo-2 armor inferior--and possibly not just in coverage.

 

I am not a big fan of repeating myself multiple times; this topic has been discussed excessively and sources have been posted here and in the Leopard 2 topic.

 

The official reports from the Comptroller General and the congressional hearing on the Leopard 2AV testing pretty much say that the biggest reason for the Leopard 2AV being considered worse protected was the armor coverage: the late XM1 prototypes had 86% more surface area covered by special armor. The Leopard 2AV also had somewhat poor armor protection, because the hull was hastly redesigned to accept special armor and Germany never had designed a hull for this type of armor previously. Some officials from the United States suggested that it was a clever idea to incorporate fuel tanks into the frontal hull armor, thus the Leopard 2AV had reduced special armor volume in the hull and a rather inefficient frontal hull armor array (replacing the fuel tanks with composite armor allowed to reach an equal or higher level of protection at a much lower weight).

 

 

The Comptroller General mentions that both the FRG and the United States weighed the protection of the perceived threats differently - given that the US Army valued protection against shaped charge warheads very high, that pretty much leaves only the optioon that Germany was more focused on protection against KE rounds. This is supported by the official protection requirements for the Leopard 2K including no protection against shaped charges (at a time when the United States were experimenting with various armor arrays to protect against shaped charge warheads) and the requirements for the Leopard 2(AV) - the Leopard 2(AV) was designed with protection against a 96 mm shaped charge (MILAN warhead) instead of a 127 mm warhead, but also against a tungsten-cored APFSDS round apparently fired from a high-pressure 105 mm smoothbore gun as fitted to the earliest ten Leopard 2(K) prototypes.

 

 

The Leopard 2K already had more than 300 mm vs KE at the turret front when hit straight on. I.e. the turret front was formed by a 38 mm high-hardness steel and a 84 mm armor steel sloped at 25° - that's 280 mm steel along the line of sight, which due to the high-hardness frontplate and spaced configuration will provide a noteworthy boost in armor protection.

 

 

Why do you think that the XM1 with three metric tons less weight, a greater frontal surface area, more armor weight & volume distributed to the flanks and with an overall physically larger size would have a higher level of KE protection?

 

2 hours ago, Olds said:

The 1978 UK chart--accurate in other respects--gives the Leo-2 a mere 300 'frontal protection.' Could it have ended up a tad higher? Sure, but not by 100+mm I'd say.

 

The UK chart is interessting, but reading too much in a single number alone doesn't make sense. The same document clearly states that the Leopard 2's armor protection was "imbalanced" and lists the effective hull armor thickness of the Leopard 1, T-62 and Centurion... "Imbalanced" could very well mean "imbalanced protection between hull and turret", which is something that can be found on the Leopard 2K and the Leopard 1 tanks with upgraded armor (Leopard 1A1A1, Leopard 1A2, Leopard 1A3). Going back to the graph leaked with the Swedish presentation and doing an analysis of the surface area of the Leopard 2 front - as done by Laviduce - leads to a hull armor protection of 280 - 340 mm vs KE on the hull; I'd call that reasonable close!

 

It is also noteworthy that the Leopard 2 hull was still being redesigned and might have included little to no special armor (as in case with the Leopard 2AV) at that time.

 

2 hours ago, Olds said:

Even Rolf Hilmes slippery slide refers to the updated (turret armor) package I think, not the original armor (obviously there was no Leo2A4 in 1979).

 

No, that is incorrect. The slide from Dipl.-Ing. Rolf Hilmes' presentation at the DPM does say Leopard 2A4, but it also lists the weight of the tank at 55.2 metric tons, which means that it refers to a Leopard 2A4 from the early production batches.

 

The Leopard 2A4 was produced with three different armor packages:

1. the original armor package was used on all Leopard 2A4 tanks produced between 1985 and 1988. This is identical to the armor package adopted on the first production variant ("Leopard 2A0") from 1979 (Germany did not pay attention to upgrading the armor until a 1986 program by the BWB).
2. the second generation armor package (in C-technology) was adoped in the middle of the sixth production batch in 1988 and was kept for the seventh batch.
3. the third generation armor package was adopted in 1991 and utilizes (D-technology). It was used on only a few tanks, all of which were later split-up, the hulls were used for the Leopard 2A5, while the turrets were mounted on some of the oldest hulls

Why does this matter? Because beginning with the adoption of the second generation armor package the weight of the tank was raised from 55.2 metric tons to 56.5 metric tons. Hilmes' citing a weight of 55.2 metric tons hence means that he either mixed up data from different variants (which would be stupid) or that he refers to the original production batches of the Leopard 2A4.

 

2 hours ago, Olds said:

It'd be hard to interpret the Krapke 1986(?) chart as approaching those high values--row 7 is especially damning. A value in the low 300's would fit however. 

 

I think you posted a wrong link, because that is refering to an article on Andrei's website about Rheinmetall's 105 mm gun. Maybe you meant this graph from Krapke's 1986 book?

 

 

This shows the KE protection of the turret armor of various German and Soviet tanks in relation to the armor penetration. As you can see, the Leopard 2 is meant to survive a 125 mm APFSDS at 1,500 m distance; the Brits estimated a penetration of 445 mm at 1,000 m distance for the Soviet tungsten-cored APFSDS in 1978 and 460 mm for the DU APFSDS round. That would fit nicely to a protection level of ~430 mm at the turret front. At this time the Soviets had adopted the 115 mm BM-28 APFSDS with a certified penetration of 380 mm at 2,000 m distance, which - if this or a similar estimation was used for the 115 mm APFSDS in the graphic - would again fit to a protection level of ~430 mm...

 

Unfortunately I don't even think that this graph is very relevant, because it seems that the values are taken from the article "Panzerwaffen: Feuerkraft und Panzerung im Vergleich" published in the Swiss defence magazine "Allgemeine schweizerische Militärzeitschrift" in 1980. After finishing the Leopard 2 project, Paul-Werner Krapke retired and moved to Switzerland, where he worked on his book and published a number of articles in the very same magazine. While he did not publish this article, he might have fallen back to the values (or is it a coincidence that all of them match? I don't believe in this coincidence). The values are estimations according to the article.

 

 

According to the article, the 115 mm APFSDS used as example is made of WHA (not steel with tungsten-carbide slug), has a length of 545 mm and a diameter of 48 mm. It can penetrate a NATO tripple heavy target at 2,000 m. I don't think such an APFSDS was ever accepted in Soviet service.

 

2 hours ago, Olds said:

P.S. FWIW, my impression is that initial German "Chobham"--such as it was--was inferior to contemporary UK & US work. It seems to me the US got the better of the armor technology deals, and the UK was more cautious in sharing with Germany during the FMBT collaboration. 

 

I'm sorry, but that is just pure bollocks. Got any source for your impression? Because according to declassified documents available in the UK National Archives,  Germany was the first choice as partner on tank and armor development for the UK. The FRG got access to the full Chobham armor technology three years before the United States (from the British perspective, the US was too much focused on Vietnam and therefore an unreliable partner for defending Europe). The UK and Germany started developing a common tank for both countries in 1972 (to replace the Chieftain and the Leopard 1), which was protected with a Chobham armor variant specifically optimized to meet the German requirements. This armor was known as Buckhorse armor. The co-development ended in 1977, because of different opinions on the conception (Germany didn't want to design a second Leopard 2, when they already were making the Leopard 2; the UK wanted a conventional tank like the Leopard 2).

 

 

2 hours ago, Olds said:

Long story short: Leo2A0 <=350 KE! Leo2A4 <=450 KE! But don't take my word for it, even the Germans knew the 80's Leo-2 and everything about it was overrated.  OK, that was going too far! Nonetheless, I do get the feeling that what fragmentary statements we have (these and a few others) correlate more probably with the low values rather than the high ones. 

 

Based on the official data leaked by the Swedish trials, the Leopard 2-2A4 (1979-1987) had ~300 mm hull and ~430 mm turret armor protection against KE ammo, which matches with the other available sources and basic physics (more mass per area = better frontal armor protection). The Leopard 2 also made use of high-quality steel with ~380 BHN for the base sturcture, which lies above what is supposedly used on some other tanks (and specifically a lot better than the 270 BHN cast armor used on Soviet turrets). There is a Russian book which claims that according to a Soviet intelligence report from the 1970s, the "German Chobham" follows the same concept as the US variant, but uses a different sandwich structure: the illustrations of the Abrams' armor array show sandwich plates in a symmetrical configuration - front and rear plates of the sandwiches are rather thin. According to the Soviet report, "German Chobham" uses much thicker front plates (25 mm) made of high-hardness steel with very thin rear plates (3 mm). This would offer improved protection against APFSDS rounds (thinner steel plates like used on the Abrams are less efficient against APFSDS rods, while high-hardness steel improves protection), but would offer - at least per weight - less protection against shaped charges.

 

When it comes to the Leopard 2(A0) and the M1 Abrams, I think the easiest way to see why the Leopard 2 should have a higher level of frontal protection is to take the following things into account:

• the Leopard 2 is physically smaller than the Abrams; it has a shorter hull, a shorter turret, a narrower turret and - if we exclude skirts - also a narrower hull. It has greater ground clearance, but is a bit taller. Overall the frontal profile is 10-15% smaller.
• the Leopard 2 focuses all its special armor on the frontal section; in case of the Abrams much more armor is used to protect the hull sides and turret bustle
• the physical armor thickness is greater on the Leopard 2
• the armor of the Leopard 2 seems to be more focused on KE protection based on previous requirements and available sources

 

 

 

The side skirts of both tanks manage to perfectly illustrate the design differences: the Leopard 2 has short but heavy ones, while the M1 Abrams has very thin ones, that cover a larger surface area.

 

Edit: Also Hans Rühle is a troll, who will say everything to reach his goal of Germany producing his own nuclear weapons. Accepting DU would be a first step in his opinion.

[Olds]

 

[Olds]

I think too much speculation is necessary to argue purely based on weight--small errors could result in large armor estimation differences so I find it to be a bit of a rabbit hole. We've all seen a million speculative assumptions that tank armor "had to be this" because of some weight or measured depth--and yet they usually end up being wrong. I certainly give your speculation more weight than average because it's well informed, but it's still speculation and it's outweighed by what (few) official docs we have for any of these vehicles.

 

Quote

I think you might be misreading the graph. It shows the protection level in relation to the percentage of the surface area that achieves such a protection level.

I understand that. But I think it might be relatively easy to end up with 20% protection well over 300 on a tank whose practical protection level was 300 (or 325 or whatever). Not because the turret was 400, but because there are plenty of frontal shot paths--especially against the turret--that go through large swaths of oblique armor (turret sides, etc.).

 

But, hey, I accept that I could be overestimating those marginal areas and the diagram reflects a stronger turret as you say. That would certainly fit better with it's label as a 2A4, right? And if that's true, then it would support my low estimate of the 2A4 (a turret in the low 400's, a hull in the low 300's). Or do you have reason to believe that "Leopard 2A4" refers to the original armor? I don't see why they wouldn't have labelled it "Leopard 2" then.

 

Quote

Based on the official data leaked by the Swedish trials, the Leopard 2-2A4 (1979-1987) had ~300 mm hull and ~430 mm turret armor protection against KE ammo, which matches with the other available sources and basic physics (more mass per area = better frontal armor protection).

OK, I see you read it as the original armor for some reason. Hmm, I'll read the posts again and see if I missed something there... No, it was just a guess. Maybe you found something in the German book which identifies Pakete B as being pre-upgrade armor?

 

Quote

I think you posted a wrong link, because that is refering to an article on Andrei's website about Rheinmetall's 105 mm gun. Maybe you meant this graph from Krapke's 1986 book?

Sorry about that, you are correct--that's the chart I was looking for. However, I find it easy to interpret quite differently:

• As you know, NATO allies did not have a uniform set of threat estimates--so it's tricky to assume because the British determined a KE threat, the Germans shared that, but...
• NATO estimates for the 115mm gun were very consistent for a long time (360mm at 0km by the UK via Taylor, 330 @1km by the US via TRADOC #1 & 10, and so on).
• The 115mm gun was perceived by NATO as penetrating no more than the low 300's at 1km. (And that's what matters, not some premium round the Soviets had in somewhere in stock that NATO appears to have been ignorant of--you've made this same point more eloquently than I in this very thread).
• Keep in mind this same gun is shown penetrating the Leo-1 at 1.8km. I honestly haven't researched the Leo-1 improved turrets, but you're not saying they were in the high 300's are you?
• As for the 125mm gun, it seems that the Germans (or this one German) simply didn't rate it as high as the Brits. Otherwise it would also be shown penetrating the Leo-1 at a heck of a lot more than 3km. (This chart likewise underestimates the T-72's armor for that matter).

 

Quote

...hence means that he either mixed up data from different variants (which would be stupid) or that he refers to the original production batches of the Leopard 2A4.

That's exactly what I think he did (intentionally or not--those mistakes happen quite frequently in presentations, so I don't think it's "stupid" regardless). After all, he's got a "Leopard 2A4" stretching back to 1979, so the versions are definitely mixed up. As I said, the slide is muddled by design or by mistake. At the very least, I'd say "it's not clear" which version he's referring to.

 

Quote

The UK chart is interessting, but reading too much in a single number alone doesn't make sense.

Official charts with protection levels are rare and valuable. I feel I must give them a lot more weight than any of our amateur 'calculations' (mine included of course). Where on earth did they get that number? Their allies weren't lying to them and the US had clearly (and correctly) indicated the M1 spec. I'm not saying that makes me right--but I wouldn't trivialize such a document--I wish we had more like it!

 

Quote

I'm sorry, but that is just pure bollocks. Got any source for your impression? Because according to declassified documents available in the UK National Archives,  Germany was the first choice as partner on tank and armor development for the UK. The FRG got access to the full Chobham armor technology three years before the United States (from the British perspective, the US was too much focused on Vietnam and therefore an unreliable partner for defending Europe). The UK and Germany started developing a common tank for both countries in 1972 (to replace the Chieftain and the Leopard 1), which was protected with a Chobham armor variant specifically optimized to meet the German requirements. This armor was known as Buckhorse armor. The co-development ended in 1977, because of different opinions on the conception (Germany didn't want to design a second Leopard 2, when they already were making the Leopard 2; the UK wanted a conventional tank like the Leopard 2).

Whoah, take it easy!  My source here is this excellent Polish article (Google Translate helps...).

• Rather limited information was shared with the Germans in 1970, "more" in 1972. It's not clear how far this extended into construction methods, however (p.119)
• In contrast, in 1973, the US received "full" information. (p.116)
• Germany was not "the first choice". While the US was approached very soon after the discovery of (NERA) in 1965, Germany was not until the early 70's--and only b/c the US had temporarily cooled in it's reception: "In the early seventies, the British realized that the fate of the Chieftain Mk.5/2 was uncertain, and the entry into service of a full replacement would take many years. Further attempts to interest the Americans in "Burlington" seemed not to be producing any results, and as a result British policy makers made contact with the Federal Republic of Germany." (p.118)

Something the Germans had in the late 70's was stolen by the Soviets and (presumably) incorporated into projects like the T-72B. I may be incorrectly interpreting that as inferior, but the US didn't seem too concerned with it as special armor (or the "Enigma" variant that showed up in the Iraq). And AFAICT, NATO has not pursued that "style" of NERA. Just a hunch though--could be wrong or unfairly impugning 'German Chobham'.

 

Anyway, I don't want to dwell on a side argument, as I respect the many well thought-out opinions here. I like my interpretation and you like yours and that's fine. Maybe some future docs will come up and clear the matter up!

 

P.S. Thanks for the great German article link, buried in there is this: ""The turret and hull [of the Leo-2A0] are equipped with state-of-the-art special armor, which provides almost unlimited protection against shaped charge projectiles and reduces the penetration power of Russian [KE] shells from the T-72 by about half compared to the Leopard 1." Guess that's subject to interpretation, but a rough idea anyway.

 

[Andrei_bt]

Suppose they had plans for ERA and "reflecting plates" also -

 

 

 

[Xlucine]

23 minutes ago, SH_MM said:

 

The Leopard 2K already had more than 300 mm vs KE at the turret front when hit straight on. I.e. the turret front was formed by a 38 mm high-hardness steel and a 84 mm armor steel sloped at 25° - that's 280 mm steel along the line of sight, which due to the high-hardness frontplate and spaced configuration will provide a noteworthy boost in armor protection.

 

 

The mantlet has considerably less protection than that, perhaps the thickness of the turret cheeks is driven by the extremes of the frontal arc instead? There's a sizeable area of mantlet with <150mm protection, which is odd for a tank with a design thickness of 280mm

[SH_MM]

30 minutes ago, Andrei_bt said:

Suppose they had plans for ERA and "reflecting plates" also -

 

 

 

Do you have the full document from where these pictures a taken? If so, can you post it?

 

This is very interesting and probably reflects the state of German armor development in 1973-1974, when the decision was made to improve armor protection. This lead to the T14 mod. turret (Leopard 2K turret that was modified with special armor).

 

There is also a photo that was posted in an English book which shows a Leopard 2K prototype with add-on armor on the hull.

 

18 minutes ago, Xlucine said:

 

The mantlet has considerably less protection than that, perhaps the thickness of the turret cheeks is driven by the extremes of the frontal arc instead? There's a sizeable area of mantlet with <150mm protection, which is odd for a tank with a design thickness of 280mm

 

Well, the mantlet is always a weak spot. But you are right, the slope is caused to provide maximum protection along a 30° arc. At 15° impact angle, the frontal armor will have a slope of 40° and an effective material thickness of 189 mm. The required protection was to stop a 105 mm APDS at 800 m distance. According to US documents, a 105 mm APDS penetrates 254 mm steel according at 1,500 m distance.

But we were ignoring the fact that tanks are not designed with protection from the direct front only in the previous discussion, thus I don't really see a big difference. The Leopard 2 would also have less than ~430 mm protection when hit at an impact angle of 30°.

 

[Andrei_bt]

yes of course, it is a german patent, I will find it's number tomorrow and post, as I remember it was early 90-s

[Olds]

6 hours ago, SH_MM said:

Well, the mantlet is always a weak spot. But you are right, the slope is caused to provide maximum protection along a 30° arc. At 15° impact angle, the frontal armor will have a slope of 40° and an effective material thickness of 189 mm. The required protection was to stop a 105 mm APDS at 800 m distance. According to US documents, a 105 mm APDS penetrates 254 mm steel according at 1,500 m distance.

But we were ignoring the fact that tanks are not designed with protection from the direct front only in the previous discussion, thus I don't really see a big difference. The Leopard 2 would also have less than ~430 mm protection when hit at an impact angle of 30°.

I wasn't, which explains some of the discrepancy. I try to stick to some sort of generic 'frontal protection level'--so, yes, typically the minimum protection for the turret (often 30 degrees to each side--obviously not by coincidence). The minimal hull protection is, of course,  almost always 0 degrees, being unsloped when viewed from above.

 

So the original M1 is about 350 KE minimum (hull and turret)--but of course the turret from 0 degrees is more like 400. I generally assume those charts do the same--the British one from 1978 certainly does: armor protection "at [the] normal". So a "300mm" Leo-2 turret would be 350 at 0, and so on.

 

Brief interruption, carry on with the 2K discussion.

[SH_MM]

8 hours ago, Olds said:

So the original M1 is about 350 KE minimum (hull and turret)--but of course the turret from 0 degrees is more like 400. I generally assume those charts do the same--the British one from 1978 certainly does: armor protection "at [the] normal". So a "300mm" Leo-2 turret would be 350 at 0, and so on.

 

You previously wrote I would speculate too much on the weight of the tanks, yet you are making even more speculations. Your sources are inconclusive and thus one should be careful with trying to make any statements based on them.

 

First of all, the British document states that the KE protection for the Abrams would reach a level of 320 to 340 mm protection against APFSDS rounds along the protected frontal arc. Given that the hull front has its minimum armor thickness of the frontal hull  is at 0° (while the side armor wasn't altered), it should not have a protection level of "350 mm KE minimum". In fact the M1A2 offered to Sweden has a protection level of 350 mm along the frontal arc of the hull - this tank has no DU armor, but that doesn't matter because only five Abrams tanks were ever created with DU armor protecting the hull. We know that the M1IP  and the M1A1 feature upgraded hull armor, which can be seen by looking at the location of the weight demonstrators. This leads to the conclusion that the M1 Abrams did not have 350 mm KE minimum for the hull, but rather 320 mm.

 

The table from the British documents lists a single value for armor protection for the Leopard 2, you are speculating what this value exactly means. First of all, "at [the] normal" can refer to the armor modules - as suggested by you - or to the tanks. Hitting a tank at normal means hitting the "front side" at perpendicular angle (the side of the tank not being affected by the shape of the armor). Against your assumption speaks the fact that the Centurion, Leopard 1 and T-62 are not listed with the respective armor thickness values they'd have when the armor was hit at the normal from within the 60° frontal arc (Leopard 1 for example would have some 50-70 mm thickness, the T-62 some ~150 mm). This implies that "at normal" means "hitting the tank directly from the front".

You are assuming that this values would refer to the turret armor; but there is no proof for this. The document doesn't say anything about the table being limited to the turret, in fact it lists the hull armor of the Centurion, the Leopard 1 and the T-62! So even if this would refer to "hitting the armor modules at normal", it still could be a value for the hull being hit at 0°.

 

Do I think that the Leopard 2 must have a protection level of 400 mm or greater at the turret when hit from a 30° angle? No, I don't think it has to. It might have a protection level in the high-300s; but I think we should find sources before making assumptions. We however know for fact that the Leopard 2 has a protection level of ~430 mm steel against KE rounds at the turret when hit directly from the front, because this value is derived from an official table by the manufacturer. So your "350 at 0" is already a false premise. You seem to be eager to "prove" that the Leopard 2 has worse frontal armor than the M1 Abrams; you are ignoring some facts, which speak for the Leopard 2 having better frontal armor (such as the greater armor weight and thickness alocated to the turret front) and you are basing everything on a single source, which leaves too much room for interpretation. As I previously stated, it seems to refer to the protection of the hull front - this would match the data from the Swedish leaks and the physical armor thickness (the hull armor of Leopard 2 and M1 Abrams has nearly identical thickness) and is supported  by the values of other tanks matching their hull armor thickness.

 

The data from the Swedish leak is inconclusive regarding the protection level of the Leopard 2, when attacked from various angles:  

As you can see, the surface area with a protection level of 400 mm or more is always larger when attacking the tank from angles other than 0°. The only question that remains is: Which places reach this protection level? The document doesn't tell anything about that, it also doesn't specify wether the area (100%) is limited to the crew compartment or not. If the latter is the case, it seems easily possible for the turret frontal section to also to be part of the protected area. Most likely the hull frontal armor reaches a protection level greater than 400 mm when hit at 20° or 30°, if the frontal hull armor is actually included in the relevant surface area.

 

The Leopard 2's turret armor has a frontal armor thickness of about 860 mm at the left turret cheek; given that the turret front is sloped at 34° in the horizontal plane, it will have a greater armor thickness when hit at 30° angle than the hull armor at 0° - overall the armor thickness might be comparable to that of the Abrams of 0° (unfortunately nobody has published proper measurements of the Abrams, but supposedly the early production model had some 700 mm physical thickness when hit at 0°). You should keep in mind that the Leopard 2(AV) was designed to resist the 105 mm smoothbore gun firing APFSDS ammo (i.e. the same projectile as used on the 120 mm DM13 with lower velocity) from unknown range. This round has a slightly higher MV and a longer & thicker tungsten penetrator than the M735 APFSDS, which is claimed to penetrate more than 300 mm steel armor.

 

 

___

 

Moving back from the armor and more to the general topic:

 

Something regarding mobility:

According to the French topic, the Leclerc squeezes 1,143 effective hp out of its 1,500 hp engine. The M1 Abrams reaches a1,232 hp net output of its AGT-1500C gas turbine, also some older discussion suggest that it might have only ~1,000 hp at the sprokets. The Leopard 2 seems to be less efficient in this regard, managing to get only 1,070 hp to the sprockets according to W. Spielberger. Leopard 1 gets 630 out of 830 hp to the sprockets. Maybe that is why the German army wishes for a 1,200 kW engine on future Leopard 2 models; however the published acceleration data suggests that the Leopard 2 beats the Abrams to 32 km/h. 

 

Regarding FCS:

In 1987 the Saudi Arabian Kingdom tested the AMX-40, the Challenger 1, the M1A1 Abrams and the EE-T2 Osorio tank. The EE-T2 Osorio was fitted with a French 120 mm smoothbore gun from GIAT and a fire control system developed by the British company Macroni. It included a 16 bit microcontroller and a SAGEM MVS 580 optic with integrated thermal imager for the commander (the same sight was later fitted to the Challenger 2E, which underwent trials in Greece). According to claims made by a Brazilian source, the Osorio was the only tank capable of hitting a stationary target in 4,000 metres distance. Against moving targets (at distances of 1,500, 2,000 and 2,500 metres), the Osorio supposedly hit eight with twelve shots. The Abrams hit 5 with twelve shots, while both of the other tanks managed to hit only a single target. The fuel consumption of the German engine was 200 g/kWh, which allowed it to travel a distance of 400 kilometres, further than any of the other three tanks.

 

In 1992 the M1A2 Abrams and the Challenger 2 were tested in Kuwait. During the tests numerous results were leaked by American representatives in order to prove that the Challenger 2 was the worse tank. In a statement made to Jane's Defence Weekly, British sources suggested that General Dynamics didn't tell the whole truth. Both tanks failed to climb a 50% slope, because it consisted of loose sand and chalk. The Challenger 2 had to be towed after driving 80 km on flat ground. Maximum speed achieved by the British tank was 50 km/h, while the Abrams managed to reach 65 km/h. The brakes of the Challenger 2 worked too slow in the opinion of the Kuwaiti officials, needing between 50 to 70 metres to come to an halt.

 

When trying to hit a T-55 tank at a distance of 4,000 metres, the M1A2 managed to hit one out of two shots (apparently it used APFSDS rounds); the Challenger 2 fired six HESH rounds at the same target, all missed. Firing at unarmored targets at distances smaller than 4,000 metres was easy for the Abrams. It hit 10 out of 10 targets, while the Challenger 2 hit only 7. Shooting on armored targets, the Challenger 2 hit four out of four shots, while the Abrams hit nine out of nine. General Dynamics' tank was also better at firing on the move; the Abrams hit three targets at a distance of 2,000 metres with three shots, while the Challenger 2 hit one out of three. In hunter-killer operations, the Abrams required 32 seconds to destroy four targets with fourt shoots; the Challenger 2 hit 3 targets out of four in 66 seconds. Accuracy when firing during night and fuel consumption had still to be measured, but Vickers believed to have an advantage there (at least in fuel consumption).

 

http://btvt.info/1inservice/abrams_vs_chelly.htm

 

 

Challenger 2 ARV towing an Abrams, which failed to climb a dune.

[SH_MM]

On 4/8/2018 at 3:31 PM, Laviduce said:

This also makes me believe that the turret "cheek" armor protection of the Challenger 1 is 500+ mm RHAe against subcalibre KE threats. The Armed Forces Journal estimate of 580 mm RHAe and the British CR1 engineer "rumor" of 620 mm RHAe seem indeed plausible.

 

 

(posted by Wiedzmin on the Tank-Net)

 

The Challenger 1 has enough armor to stop a 125 mm APFSDS at about 1,000 metres distance. Given that the British estimated a penetration performance of 475 mm steel armor at 0 metres for a 125 mm tungsten-cored APFSDS round, it seems likely that the Challenger 1 has 400-450 mm protection vs KE; this also would match the statement that the Challenger 1 has protection roughly equal to a T-64BV, T-72AV or T-80BV tank.

 

The Challenger 2 design - not necessarily identical to the production model - at some point of time was to have improved hull armor; there is no mention of upgraded turret armor (at that time).

 

 

That leads to:

• XM1 Abrams - resists 115 mm APFSDS at 800 - 1,200 metres (official requirement), penetrated by 125 mm APFSDS even at 4,000 metres (British claims)
• Leopard 2 - turret resists 115 mm APFSDS at 1,000 metres & 125 mm APFSDS at 1,500 metres (Swiss estimates)
• Challenger 1 - turret resists 125 mm APFSDS at 1,000 metres, hull weaker
• Challenger 2 - turret and hull resist 125 mm APFSDS at 1,000 metres (design specifications)
• Chieftain with Stillbrew - turret resists 105 mm APFSDS point blank and 120 mm APFSDS at 1,000 metres

[Laviduce]

5 hours ago, SH_MM said:

 

 

(posted by Wiedzmin on the Tank-Net)

 

The Challenger 1 has enough armor to stop a 125 mm APFSDS at about 1,000 metres distance. Given that the British estimated a penetration performance of 475 mm steel armor at 0 metres for a 125 mm tungsten-cored APFSDS round, it seems likely that the Challenger 1 has 400-450 mm protection vs KE; this also would match the statement that the Challenger 1 has protection roughly equal to a T-64BV, T-72AV or T-80BV tank.

 

The Challenger 2 design - not necessarily identical to the production model - at some point of time was to have improved hull armor; there is no mention of upgraded turret armor (at that time).

 

 

That leads to:

• XM1 Abrams - resists 115 mm APFSDS at 800 - 1,200 metres (official requirement), penetrated by 125 mm APFSDS even at 4,000 metres (British claims)
• Leopard 2 - turret resists 115 mm APFSDS at 1,000 metres & 125 mm APFSDS at 1,500 metres (Swiss estimates)
• Challenger 1 - turret resists 125 mm APFSDS at 1,000 metres, hull weaker
• Challenger 2 - turret and hull resist 125 mm APFSDS at 1,000 metres (design specifications)
• Chieftain with Stillbrew - turret resists 105 mm APFSDS point blank and 120 mm APFSDS at 1,000 metres

Thank you for your response, I appreciate the effort. I hope more information gets released and found.   It seems quite a few tanks protection capabilities have been overhyped.

This makes me believe that the protection requirement estimates  in the Chieftain book by Richard Taylor are referring to the protection offered at 1000m and not point blank range.

 

Questions:

 

1) At what distance does the Challenger 2 turret (cheeks?) and glacis offer protection against the 125 mm rounds of the T-72?  Is it at 1000m and above or at point blank distances? In the image i could not see the distance given for the Challenger 2.

 

2) From what document does this information come from?

 

3) How old is this document?

[SH_MM]

On 3/18/2018 at 12:22 PM, Laviduce said:

Updated volume model:

 

 

According to the following drawing, the gun mantlet armor is actually a lot thinner, because the 420 mm thickness are also the trunnion of the main gun!

 

 

 

The Type 90 tank seems to be rather poorly protected.

[Laviduce]

On 5/7/2018 at 12:02 PM, SH_MM said:

 

According to the following drawing, the gun mantlet armor is actually a lot thinner, because the 420 mm thickness are also the trunnion of the main gun!

 

 

 

The Type 90 tank seems to be rather poorly protected.

 

The mantlet drawing in the first image must be wrong. The vertical movement axis seems to be further back.  The 420 mm that i got  are maximum values. My first estimate for the actual mantlet not including the trunnion was around 380-400 mm. I was told that the mantlet was thicker than that. I will not name names.

 

Also the mantlet in your image that is labelled as ~200 mm should be more like 270-280 mm. The part labelled as trunnion? is about 260 mm thick. This would give us LOS thickness of about 540 mm. 

 

After having taken a closer look at the mantlet setups on the Leopard 2 and Leclerc tanks, i have come to the conclusion that the trunnion of the Type 90 could be located right above the turret ring  edge.

 

If we have position the 200 mm thick trunnion block according to the available drawings and models (i.e.Tamiya), this would leave us with about 390 mm of space to work with for the actual trunnion thickness. I will make the changes.

 

--------------------------------------------------------------

Small update with change:

 

 

[SH_MM]

 

 

 

From the Strong Europe Tank Challenge 2018. The dispersion of five round fired by a Swedish Strv 122 (at just 500 metres distance).

 

 

Interim results... note that Romania is missing (no show?).

[Alzoc]

46 minutes ago, SH_MM said:

Interim results... note that Romania is missing (no show?).

 

Romania?

 

Spoiler

 

Were they supposed to come?

[SH_MM]

52 minutes ago, Alzoc said:

 

Romania?

 

  Hide contents

 

Were they supposed to come?

 

Yes, they were originally meant to participate. But it is not the first time that some country had to cancel, the Czechs did that already in 2016.

[Alzoc]

Too bad I guess.

I would have liked to see one of their modified and modernized T-55

[SH_MM]

19 hours ago, SH_MM said:

 

Interim results... note that Romania is missing (no show?).

 

Apparently one of the T-84 tanks had a fire control system malfunction resulting in the low score. T-64s with upgraded FCS managed to get 329 points last year.

[Lord_James]

Britain doesn’t appear to be doing very well... I wonder why 

[Alzoc]

20 minutes ago, Lord_James said:

Britain doesn’t appear to be doing very well... I wonder why 

 

Well it's their first time in the competition, so they are probably simply unfamiliar with how the scoring system works (Although the same apply for the Swedes).

I've read that last year the pistol shooting range was quite unexpected for our tankers for example.

 

Also comparing the scores of that edition to the previous one it is possible that scoring became harder this year:

 

Spoiler

 

[Ramlaen]

Sweden, Austria and Germany have a distinct lead in offensive scoring, in comparison the defensive scoring had a small spread.

 

[LoooSeR]

Ukraine have low score. AFAIK there are problems with T-84s.

[SH_MM]

13 minutes ago, LoooSeR said:

Ukraine have low score. AFAIK there are problems are with T-84s.

 

Yes, even their ministry reported that:

 

Quote

During the first day, the Ukrainian tank platoon executed the offensive task and had to accomplish a range of manoeuvres.

This day was not successful for our team: tactical actions got the highest mark; meanwhile, firing task was failed due to technical problems. The result was 208 points. There are 12 more phases to improve the situation.

 

http://www.mil.gov.ua/en/news/2018/06/05/strong-europe-tank-challenge-2018-offensive/

[Lord_James]

On 6/6/2018 at 1:38 PM, Alzoc said:

 

Well it's their first time in the competition, so they are probably simply unfamiliar with how the scoring system works (Although the same apply for the Swedes).

I've read that last year the pistol shooting range was quite unexpected for our tankers for example.

 

Also comparing the scores of that edition to the previous one it is possible that scoring became harder this year:

 

  Reveal hidden contents

 

 

I was more implying their choice of (subpar) weaponry. ‘cough’ rifled main gun ‘cough’