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#1 Gman

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Posted 25 July 2017 - 1815 PM

I was wondering if anyone has any specific details available online for comparisons of M1 (original) Abrams, IPM1, Leopard 2A3, T64, T72A and T80 for resistance from KE and CE rounds ? Looking at comparisons for basic armour packages if possible.

 

I understand Lakowski was previously highly regarded but heard there is some doubts since ?

 

As I understand it the original Soviet ERA also had minimal to nil effect upon KE rounds ?



#2 rmgill

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Posted 25 July 2017 - 2139 PM

Much of that data is going to be covered by classification rules still I'll bet. 



#3 Gman

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Posted 26 July 2017 - 0010 AM

Thanks rmgill.

 

I know that Lakowski has written extensively but have heard many negatives about him on this grate sight.

 

Was curious as I searched here and found very little on the subject.  Pretty sure not much is still secret about T64/T72/T80 now and no one has used M1 or IPM1 for a good 20+ years. Even the Leo2A3 is long out of currency for most countries..



#4 Stuart Galbraith

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Posted 26 July 2017 - 0245 AM

Paul seems a pretty nice guy actually. He was very helpful to me on a couple of things I was working on.

 

I never personally dont recall any complaints here about accuracy on his part, the only part I disagreed with him over was he had something of an over optimistic opinion of the cladding on the inside of British tanks, determining it would be helpful against behind armour effects like spalling. In fact when Ive looked at it in the Bovington back lot, it seemed to be just what British crewmen said it was, to stop them bumping their head with minimal effects on spall.

 

Now information moves on, I know that there is new information that has come out since 2000 on the efficacy of Soviet armour, but that doesn't mean he was wrong to make the calculations he did with the data that was available.


Edited by Stuart Galbraith, 26 July 2017 - 0246 AM.


#5 bojan

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Posted 26 July 2017 - 0742 AM

His estimates were groundbreaking, but are heavily dated - wrong dimensions of armor, wrong composition etc. They can be taken as very rough ballpark figure, but for better you would have to dig more, and a lot of stuff is still classified.



#6 methos

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Posted 26 July 2017 - 0820 AM

Well, first of all using steel equivalency is a rather bad idea. The interaction between each armor type and penetrator type are unique, trying to shoehorn the provided protection into one single value vs all different types of APFSDS ammo doesn't work. There are research papers that have shown the flaws of RHA equvaliencies, the company Rheinmetall has stated - publicly and also in documents not available to the public - that RHA values are useless to represent modern armors, APFSDS ammunition isn't even tested against RHA anymore unless a customer demands it.

The values from Paul Lakowski are very questionable, I wouldn't rely on them. The assumed armor layouts, weight values and armor thickness values are completely off, most tanks are better/worse protected than others, simply because he assumed that the armor itself will provide more protection per weight.

 

 

That said a lot of older documents from the Cold War were completely focused on RHAe values. One document from the CIA/US Army, which has been declassified via the Freedom of Information Act, mentions that "one version of the M1 turret is rated as 750mm RHA against chemical munitions and 400mm RHA against kinetic energy munitions." Based on the age of the document (M1A1 had not entered service yet), this means that the data should be based on the basic M1 Abrams. Rheinmetall included a graph with armor and penetration estimations in one of its presentation, which put the M1 Abrams' armor at 350 mm vs KE (not mentioning if this is the turret or hull; also not mentioning the angle of impact). S. Zaloga has used the same value in one of his older books, also stating a protection level of 700 mm RHA vs CE.

 

During the late 1970s the British Army was developing a tank known as the MBT80, which was canceled in favour of adopting the Challenger 1 (that was originally meant to be an export tank designated FV4030/3 "Shir Iran" for Persia). There are documents from a computer simulation comparing the armor protection of the MBT80 and the XM1 Abrams. Based on the photos of the 3D models used in this simulation and the age of this simulation, it appears that the XM1 Abrams was the late FSED prototype from Chrysler, which was identical with the first production model of the M1 Abrams.

The simulation estimated that the probability to penetrate an XM1 with a KE round is 73%, with an ATGM is 50% and with an RPG is 25%. Hull down this drops to 53% (KE), 23% (ATGM) and 17% (RPG). The MBT80 was better protected with a simulated probability of only 65% penetrating the fully exposed tank with a KE round, but 58% and 30% with ATGM and RPG respectively. The hull of the vehicle was apparently not well armored against shaped charge weapons, because in hull down the probability of penetrating the MBT80 was only 28% with an APFSDS round, 21% with an ATGM and 11% with an RPG!

How much this says about the Challenger 1 is hard to say, as it wasn't a related development.

 

The Leopard 2's frontal armor has an areal density of about 3.5 metric tons per square metre according to German sources, which is equal to about 450 mm thick steel. It is not specified wether this is the average weight (suggesting the hull armor might have slightly less areal densit, while turret armor has slightly more), maximum armor weight or whatever else. The Leopard 2's turret armor package weighs 8 metric tons. Given that composite armor is designed to provide more protection per weight (the Leopard 2's armor has been claimed to include high-hardness steel, ceramics and/or tungsten by different sources), one should assume something in the area of 500-550 mm RHA vs KE.

This figure also is supported by other sources. In a book from 1986 written by Paul-Werner Krapke, originally leitender Baudirektor (~ project manager) of the Leopard 2 development, it is claimed that the Leopard 2 frontal armor resists a 125 mm APFSDS from 1,500 metres distance (for comparison, the original M1 Abrams was designed to resist 115 mm APFSDS from 800 m); this would again point to something in the area of ~550 mm RHA vs KE based on the penetration data of existing Soviet APFSDS ammo, and German APFSDS rounds (120 mm DM13, 120 mm DM23) that could have been used to simulate 125 mm APFSDS rounds.

The Leopard 2AV was designed to resist a 105 mm APFSDS round from 800 m (believed to be a round fired by the smoothbore gun of the Leopard 2K prototypes with 38 mm core diameter) and the MILAN ATGM with 600-650 mm penetration. The series Leopard 2 had better armor (at least in terms of coverage), which was kept until the Leopard 2A4.

 

On Soviet protection levels, there are multiple estimates available from declassified CIA documents, aswell as old Soviet/Russian documents. Harkonnen has published nice articles on his websites in the past, you need Google translator or other software to them however. In general the protection level of T-64A/B, T-72A and T-80B is believed to be in the area of 450-550 mm RHA vs KE and 500-600 mm RHA vs CE.



#7 Stuart Galbraith

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Posted 26 July 2017 - 0956 AM

Methos, do you know what study that was? Ive one on a comparative study of different tank configurations to replace Chieftain, but ive not seen that one.



#8 methos

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Posted 26 July 2017 - 1029 AM

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#9 EasyE

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Posted 26 July 2017 - 2336 PM

Well RHA values are roughly estimated. Soviet tanks of the time mostly had a steel-textolite mix. T-72B had a NERA set up. Nato tanks had their own NERA arrays, perhaps with some ceramics, Leo-2 it is suspected had a perforated steel and or German NERA array.

 

Turret Values from head on thickest LOS.

 

M1-400 420 KE -750mm 800mm CE

iPM1- 550-600mm KE 800-1100 CE

 

Leopard 2A3- 450-500mm KE ~800mm CE

 

Russian tanks because of the geometry of the turret can have some very high values near the edges of the turret corners.

 

T-64B 400-450mm KE 500-550mm CE

 

T-72A 420-450mm KE 450-500mm CE

 

T-80B 450-500mm KE 500-550mm CE

 

These are very rough values and not a golden rule about which round will kill what tank. VS KE most of the tanks converge on the same values, with the outlier being the IPM-1 with BRL-2 armor package with about 900mm LOS thickness.

 

For example APFSDS design can strongly decided if you defeat an armor package or not.  A monoblock DU round like the M-833 will do far better against a composite armor package then say BM-26 with a steel body and tungsten plug construction. A NERA set up will bend, yaw, and cause misalignment of parts of the round likely causing critical failure during the penetration process.  Both rounds introduced around the same time would defeat roughly the same amount of a steel target at reasonable angles and ranges.

 

Translated into the real world...BM-26 might have a tough time against the turret front of the M1 Abrams where the M-833 would probably have little trouble. I have doubts about Soviet APFSDS to be effective against the armor packages of most heavy western armor packages. The compromises required to make a non monoblock APFSDS in mass, created rounds with poor performance against complex armor packages.

 

Lakowski published values a while ago and some of the assumptions were not even close to reality. He has provided revised values to ESim games and their Steel Beasts game as far as I know.

 

"As I understand it the original Soviet ERA also had minimal to nil effect upon KE rounds ?"

 

Near Zero...K5 was effective, although not as much as many claim. A thin round traveling less then 1550m/s had a good chance of not initiating the reaction IIRC.



#10 EasyE

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Posted 27 July 2017 - 0009 AM

Well, first of all using steel equivalency is a rather bad idea. The interaction between each armor type and penetrator type are unique, trying to shoehorn the provided protection into one single value vs all different types of APFSDS ammo doesn't work. There are research papers that have shown the flaws of RHA equvaliencies, the company Rheinmetall has stated - publicly and also in documents not available to the public - that RHA values are useless to represent modern armors, APFSDS ammunition isn't even tested against RHA anymore unless a customer demands it.

The values from Paul Lakowski are very questionable, I wouldn't rely on them. The assumed armor layouts, weight values and armor thickness values are completely off, most tanks are better/worse protected than others, simply because he assumed that the armor itself will provide more protection per weight.

 

 

That said a lot of older documents from the Cold War were completely focused on RHAe values. One document from the CIA/US Army, which has been declassified via the Freedom of Information Act, mentions that "one version of the M1 turret is rated as 750mm RHA against chemical munitions and 400mm RHA against kinetic energy munitions." Based on the age of the document (M1A1 had not entered service yet), this means that the data should be based on the basic M1 Abrams. Rheinmetall included a graph with armor and penetration estimations in one of its presentation, which put the M1 Abrams' armor at 350 mm vs KE (not mentioning if this is the turret or hull; also not mentioning the angle of impact). S. Zaloga has used the same value in one of his older books, also stating a protection level of 700 mm RHA vs CE.

 

During the late 1970s the British Army was developing a tank known as the MBT80, which was canceled in favour of adopting the Challenger 1 (that was originally meant to be an export tank designated FV4030/3 "Shir Iran" for Persia). There are documents from a computer simulation comparing the armor protection of the MBT80 and the XM1 Abrams. Based on the photos of the 3D models used in this simulation and the age of this simulation, it appears that the XM1 Abrams was the late FSED prototype from Chrysler, which was identical with the first production model of the M1 Abrams.

The simulation estimated that the probability to penetrate an XM1 with a KE round is 73%, with an ATGM is 50% and with an RPG is 25%. Hull down this drops to 53% (KE), 23% (ATGM) and 17% (RPG). The MBT80 was better protected with a simulated probability of only 65% penetrating the fully exposed tank with a KE round, but 58% and 30% with ATGM and RPG respectively. The hull of the vehicle was apparently not well armored against shaped charge weapons, because in hull down the probability of penetrating the MBT80 was only 28% with an APFSDS round, 21% with an ATGM and 11% with an RPG!

How much this says about the Challenger 1 is hard to say, as it wasn't a related development.

 

The Leopard 2's frontal armor has an areal density of about 3.5 metric tons per square metre according to German sources, which is equal to about 450 mm thick steel. It is not specified wether this is the average weight (suggesting the hull armor might have slightly less areal densit, while turret armor has slightly more), maximum armor weight or whatever else. The Leopard 2's turret armor package weighs 8 metric tons. Given that composite armor is designed to provide more protection per weight (the Leopard 2's armor has been claimed to include high-hardness steel, ceramics and/or tungsten by different sources), one should assume something in the area of 500-550 mm RHA vs KE.

This figure also is supported by other sources. In a book from 1986 written by Paul-Werner Krapke, originally leitender Baudirektor (~ project manager) of the Leopard 2 development, it is claimed that the Leopard 2 frontal armor resists a 125 mm APFSDS from 1,500 metres distance (for comparison, the original M1 Abrams was designed to resist 115 mm APFSDS from 800 m); this would again point to something in the area of ~550 mm RHA vs KE based on the penetration data of existing Soviet APFSDS ammo, and German APFSDS rounds (120 mm DM13, 120 mm DM23) that could have been used to simulate 125 mm APFSDS rounds.

The Leopard 2AV was designed to resist a 105 mm APFSDS round from 800 m (believed to be a round fired by the smoothbore gun of the Leopard 2K prototypes with 38 mm core diameter) and the MILAN ATGM with 600-650 mm penetration. The series Leopard 2 had better armor (at least in terms of coverage), which was kept until the Leopard 2A4.

 

On Soviet protection levels, there are multiple estimates available from declassified CIA documents, aswell as old Soviet/Russian documents. Harkonnen has published nice articles on his websites in the past, you need Google translator or other software to them however. In general the protection level of T-64A/B, T-72A and T-80B is believed to be in the area of 450-550 mm RHA vs KE and 500-600 mm RHA vs CE.

 

If I recall correctly from a conversation I had a few years ago with a tanker in the USA who was on the M1 in the early 1980s, western intel thought that the USSR was able to produce in mass APFSDS at the same level or better technology that the west was introducing at the time. Ie monoblock with similar LD ratios...the advice given to them was, "don't get hit"

 

I have to wonder if that went into assumptions about the survivability of the XM-1 etc.



#11 Stuart Galbraith

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Posted 27 July 2017 - 0353 AM

Thanks Methos, thats really very interesting. I know when Bob Griffin was trying to find information on MBT80 some years ago, it was rare to nonexistant, so they must be really opening the archives up on that period now.



#12 methos

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Posted 27 July 2017 - 0540 AM

EasyE, the US Army had underestimated the capabilities of the Soviet tank guns by quite a bit, that's why the M1 Abrams turned out to be rather under-armored for its time. To quote the 1982 report from where I took the values (400 mm RHA vs KE, 800 mm RHA vs CE):

"The study that recommended development of the M1 Abrams MBT stated that the T-72 would have a 115mm main gun capable of penetrating 147mm RHA at 60° obliquity at 1,000M and 120mm of RHA at 60° obliquity at 2,000M. In justifying the predicted retention of the 115mm gun (although a caveat was included that other reported calibers might include 122, 125, and 130mm), ITAC stated that the penetration design could be improved. The gun chamber volume and tube length could also be increased. In fact, the weapon developed was a 125mm gun capable of penetrating 161mm RHA at 60° obliquity at 2,000M. Again in 1981, it was forecast that the NST (T-80) and FST (T-80 FO) would retain the 125mm gun, but have an improved projectile and increased chamber pressure."

 

The US Army understimated the Soviet tank development and assumed that the 115 mm gun would remain the main threat for tanks. NATO at the time (at least the USA and West-Germany) did still believe that the T-80 would enter service somewhere during the mid-1980s. Even in 1982, the penetration power of the Soviet APFSDS was still underestimated. Considering what the US believed to be the state of Soviet tank development, demanding protection only against 115 mm APFSDS from 800 m distance seemed to be a good idea; unfortunately NATO/the United States didn't knew enough about Soviet weapons at the time, in case of a war in 1980, NATO would have been suprised quite a lot. Even in 1982 penetration levels were far below of what Soviet APFSDS was capable to do.

 

Well, the original Leopard 2 design with spaced armor (protection against 105 m APDS at 800 m distance along a 30° frontal arc) was obiously worse, but the relatively late armor re-desgin (three years after the US adopted Burlington armor) + a second redesign after US tests of the Leopard 2AV) seems to have paid off. 

 

From what I know, the "perforated armor" of the Leopard 2 seems to be a myth spawned by some internet users. I have not seen any German language source suggesting anything, no official document, no mention in a book and also no patent. German armor seems to be NERA mainly, but might follow a different layout compared to US/British armor based on what I have heard/read. The Abrams' armor shouldn't really provide much greater protection against a BM-26 APFSDS or similar designs; in order to be effective against APFSDS ammo, NERA requires thick plates and/or high-hardness steel as material. The NERA array used on the early Abrams, at least at the places for which we have data, seems to be based around very thin steel plates only. This such provide no additional protection over homogenous or spaced steel plates according to literature.

 

 

Stuart, unfortunately I don't know anything further about what is available in the archives and since when. This was posted to another forum, I simply remembered having seen it. But it would be nice to find out some more about the MBT80 and the protection level of the Challenger 1.


Edited by methos, 27 July 2017 - 0541 AM.


#13 Rick

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Posted 27 July 2017 - 0600 AM

From memory, wasn't there a German Army tank gun test against some ex-East German tanks shortly after the reunification?



#14 bojan

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Posted 27 July 2017 - 0844 AM

If I recall correctly from a conversation I had a few years ago with a tanker in the USA who was on the M1 in the early 1980s, western intel thought that the USSR was able to produce in mass APFSDS at the same level or better technology that the west was introducing at the time.

 

Well, they did introduce monoblock DU BM-32 in 1985 which was slightly better than original M829.

It is still a big unknown how much west knew about Soviet APFSDS ammo, since most samples acquired, even in 1991. Iraq were pretty old ones.


Edited by bojan, 27 July 2017 - 0845 AM.


#15 Wiedzmin

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Posted 27 July 2017 - 1507 PM

what study that was? 

http://discovery.nat...ils/r/C11426898



#16 EasyE

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Posted 28 July 2017 - 1208 PM

EasyE, the US Army had underestimated the capabilities of the Soviet tank guns by quite a bit, that's why the M1 Abrams turned out to be rather under-armored for its time. To quote the 1982 report from where I took the values (400 mm RHA vs KE, 800 mm RHA vs CE):

"The study that recommended development of the M1 Abrams MBT stated that the T-72 would have a 115mm main gun capable of penetrating 147mm RHA at 60° obliquity at 1,000M and 120mm of RHA at 60° obliquity at 2,000M. In justifying the predicted retention of the 115mm gun (although a caveat was included that other reported calibers might include 122, 125, and 130mm), ITAC stated that the penetration design could be improved. The gun chamber volume and tube length could also be increased. In fact, the weapon developed was a 125mm gun capable of penetrating 161mm RHA at 60° obliquity at 2,000M. Again in 1981, it was forecast that the NST (T-80) and FST (T-80 FO) would retain the 125mm gun, but have an improved projectile and increased chamber pressure."

 

The US Army understimated the Soviet tank development and assumed that the 115 mm gun would remain the main threat for tanks. NATO at the time (at least the USA and West-Germany) did still believe that the T-80 would enter service somewhere during the mid-1980s. Even in 1982, the penetration power of the Soviet APFSDS was still underestimated. Considering what the US believed to be the state of Soviet tank development, demanding protection only against 115 mm APFSDS from 800 m distance seemed to be a good idea; unfortunately NATO/the United States didn't knew enough about Soviet weapons at the time, in case of a war in 1980, NATO would have been suprised quite a lot. Even in 1982 penetration levels were far below of what Soviet APFSDS was capable to do.


 

From what I know, the "perforated armor" of the Leopard 2 seems to be a myth spawned by some internet users. I have not seen any German language source suggesting anything, no official document, no mention in a book and also no patent. German armor seems to be NERA mainly, but might follow a different layout compared to US/British armor based on what I have heard/read. The Abrams' armor shouldn't really provide much greater protection against a BM-26 APFSDS or similar designs; in order to be effective against APFSDS ammo, NERA requires thick plates and/or high-hardness steel as material. The NERA array used on the early Abrams, at least at the places for which we have data, seems to be based around very thin steel plates only. This such provide no additional protection over homogenous or spaced steel plates according to literature.

 

 

 

 

That I don't dispute. I am not referring to the guns really but being very specific about ammunition design. One things that has become very clear to me during my study of this topic is that against complex armor arrays the term APFSDS is far from all encompassing so statements from the literature unless specified are not totally useful in this context. Rounds like the BM-26 and the M883 have different penetration mechanics against steel armor, similar performance. When it comes to the penetration mechanics against spaced arrays and complex arrays with NERA, the comprise in the design of early 125mm ammo start to result in a very sharp drop off in performance. Bm-22/26 don't perform well against spaced armor arrays, so there is little reason to think that a ~700mm array with 4 NERA plates "could" not be effective. Even thin plates will introduce asymmetric loading in a projectile with multiple components of different densities and dimensions. The steel body after some penetration acts as a support to the Tungsten slugs, in effect ensuring they have a lateral pathway through the rest of the armor. Against sandwich type arrays (like the ones the Soviets assumed would be the armor layout of western designs this still works reasonably well.

 

Still depends on a great deal of unknowns when it comes to defeating the armor package of the M1. Almost certainly a NERA set up for the turret, what type of steel is used (HHS?) is there a ceramic backing plate? as there appears to be on the turret side. I could see a Bm-32 having no problems, BM-22/26...hmmm I disagree with you here, very specific designs against a very specific target type, and too easy to cause critical failure of the round. Not saying it isn't possible to defeat the M1 armor package. Seems like armor and ammo were at the limits of what each could handle with regards to each other.

 

Zero doubt the Leo-2 could manage better. As far as perforated armor goes, I have vague memories of reading about it in the past as a German French approach.. but have seen no evidence of it further then that.



#17 EasyE

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Posted 28 July 2017 - 1313 PM

 

If I recall correctly from a conversation I had a few years ago with a tanker in the USA who was on the M1 in the early 1980s, western intel thought that the USSR was able to produce in mass APFSDS at the same level or better technology that the west was introducing at the time.

 

Well, they did introduce monoblock DU BM-32 in 1985 which was slightly better than original M829.

It is still a big unknown how much west knew about Soviet APFSDS ammo, since most samples acquired, even in 1991. Iraq were pretty old ones.

 

 

How was it better then the M829?

 

It is shorter, 530-540mm vs 380mm

 

Worse LD ratio 22:1  vs 16:1

 

It does weigh slightly more 4.3kg vs 4.8kg.

 

It slows far more rapidly and only is 50m/s faster out of the muzzle. 1650 vs 1700 m/s

 

Alloy is less advanced and I have read nothing regarding Nickle Zink alloyed with DU giving better characteristics for a penetrating rod, especially against complex armor arrays.

 

Penetration figures I see..250mm vs 280- 60 deg at 2km. Matches closely what I calculate.

 

What am I missing here?

 

I think that in the USA once the defense budget was in full on Reagan mode, they just felt more freedom to assume the worst and adjust their budget accordingly.



#18 methos

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Posted 29 July 2017 - 0546 AM

From memory, wasn't there a German Army tank gun test against some ex-East German tanks shortly after the reunification?

 
Yes, there were tests of five T-72M1 against German guns and ammunition in the early 1990s. However more exact information are hard to find, because the only source of this were a few photos published on the website of Jörg Siegert, a former ex-East-German soldier. Since a few years the photos (and the few lines of description) are gone, maybe the traffic was too much as people tended to hot-link the photos on other sites, or he decided to included the photos in one of the books he has written in the past few years.
 
There really isn't much shown aside that unknown ammunition managed to penetrate the T-72M1, while other unknown ammunition had issues (i.e. sometimes HEAT rounds, but one cannot see if all APFSDS also penetrated). Here are a few of the photos:
hc4wfHj.gif5tJe1rX.gifXJHYYHh.giflNpH935.gif
 
 

That I don't dispute. I am not referring to the guns really but being very specific about ammunition design. One things that has become very clear to me during my study of this topic is that against complex armor arrays the term APFSDS is far from all encompassing so statements from the literature unless specified are not totally useful in this context. Rounds like the BM-26 and the M883 have different penetration mechanics against steel armor, similar performance. When it comes to the penetration mechanics against spaced arrays and complex arrays with NERA, the comprise in the design of early 125mm ammo start to result in a very sharp drop off in performance. Bm-22/26 don't perform well against spaced armor arrays, so there is little reason to think that a ~700mm array with 4 NERA plates "could" not be effective. Even thin plates will introduce asymmetric loading in a projectile with multiple components of different densities and dimensions. The steel body after some penetration acts as a support to the Tungsten slugs, in effect ensuring they have a lateral pathway through the rest of the armor. Against sandwich type arrays (like the ones the Soviets assumed would be the armor layout of western designs this still works reasonably well.
 
Still depends on a great deal of unknowns when it comes to defeating the armor package of the M1. Almost certainly a NERA set up for the turret, what type of steel is used (HHS?) is there a ceramic backing plate? as there appears to be on the turret side. I could see a Bm-32 having no problems, BM-22/26...hmmm I disagree with you here, very specific designs against a very specific target type, and too easy to cause critical failure of the round. Not saying it isn't possible to defeat the M1 armor package. Seems like armor and ammo were at the limits of what each could handle with regards to each other.
 
Zero doubt the Leo-2 could manage better. As far as perforated armor goes, I have vague memories of reading about it in the past as a German French approach.. but have seen no evidence of it further then that.

 
I think you are making a mistake by assuming to know the exact behaviour of each round just because you know the general type of the penetrator layout. There have been very different statements on the performance of rounds with a similar general penetrator layout, but important and specific differences. For example the Rheinmetall claimed that the German 120 mm DM13 APFSDS for the Leopard 2 was capable of dealing with more complex armor arrays than other types of similar APFSDS designs. The DM13 was a tungsten penetrator with steel sheathing, but has been claimed to penetrate targets armored with multiple spaced steel plates without a major reduciton in penetrator power - something not possible with earlier/simpler APFSDS rounds with sheathed tungsten/DU penetrators such as the M735(A1), BM-15, BM-22, etc. These could penetrate simply spaced armor to some extend, but suffered froma  heavy loss of penetration power against multiple spaced armor layers. A lot of time and research was invested in developing the DM13 APFSDS (XM827).
 
Early US ammunition (M392, M735 and M774) all suffered from core break-up, that considerably diminished the penetration capabilities. Even the XM829 (M829 prototype) demonstrated this behaviour. So even the penetration values for the US ammunition didn't have to represent the real life penetration performance of said rounds.
 
The BM-26 APFSDS is a very unique design, the only APFSDS round, at least the only I know where the tungsten penetrator is located at the rear section of the projectile. It also was the first Soviet APFSDS specifically designed to counter special armor arrays - it seems unreasonable to assume that it will showcase the same bad performance of the earlier rounds, which were only designed to deal with homogenous armor. Due to its construction, the steel body most likely won't act as a support for the tungsten slug as claimed by you. Monobloc penetrators are not perfect, that's why there aren't used anymore - at least in some countries. Jacketed penetrators for example have shown to retain more of their original penetration compared to monobloc penetrators when used against spaced armor targets. This doesn't mean that the BM-26 will perform as good as a monobloc penetrator against spaced armor/NERA targets, but it could be possible... who knows what the exact reference target during the development of the BM-26 APFSDS was? The Soviets supposedly knew about NATO working with NERA arrays since the late 1970s.
 
 
As for the M1 Abrams armor, I think the most reasonable thing is to assume that the frontal turret armor will look similar to the frontal hull armor and the gun mantlet armor module. In the end the frontal armor is designed to resist the same threats and hit with roughly the same probability (ignoring the difference in hull vs turret hits at least). This would mean that it consists of spaced NERA sandwich plates as well as thick steel walls, no ceramic material or HHS (proper HHS at the time was not suited for welding and thickness was limited, so it could not be used for sturctural parts such as the interor walls of the turret). 
It is however possible that the turret frontal armor for some unknown reasons looks completely different - but why would that be? It was designed with the same protection level as the hull. 
There is no proof that there is any ceramic in the Abrams. There is some unknown material, that might be ceramic, in the turret bustle, but the turret bustle is very different from the rest of the turret (it has three to four inches thicker armor and is apparently designed to resist RPGs/older ATGMs from perpendicular impact, while the rest of the turret side armor is designed to protect along the frontal arc when hit at angles up to 30°). If the material is actually a type of ceramic is not confirmed, there are at least two reasons to question that: bolts are going through the material (something not really possible with ceramic tiles but the drawing might be inaccurate/simplifyied) and the material is not completely confined (debris of shattered ceramic material would fall out at the top and bottom, also the protection level of the edges would be much lower). In actual ceramic armor modules of modern construction (such as MEXAS), the ceramic tiles are confined within a metal frame to reduce the weakness at the edges and debris/material falling away after impact.
 

How was it better then the M829?


I also doubt that it should reach a better or the exactly identical level of penetration based on its dimensions; the rod is just too short. But it has a few advantages. The lower L/D-ratio allows a higher efficiency (the greater the L/D ratio, the lower the penetration per given length), also the impact velocity might still be identical or higher, depending on the exact deceleration of each round.



#19 Wiedzmin

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Posted 29 July 2017 - 1243 PM

 

 

 

How was it better then the M829?

 

It is shorter, 530-540mm vs 380mm

 

 

380 for 3BM32 it's core  length IIRC not projectile(480mm) 

 

and M829 core without fins and cap is how long ? same 380-400mm ? 

 

I'm not saying that 3BM32 better than M829, but interested in real lengths etc 



#20 methos

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Posted 29 July 2017 - 1247 PM

M829 has a total length of 627 mm and an estimated penetrator (core) of 530-540 mm length.






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