Main Battle Tanks and Armour Technology

[hest]

Soviet APFSDS were tested to measure performance, apart from typical 60 degree RHA element, against composite armour block.

For example in 80s they were tested against P-11 block by NII Stali. Target consisted of multi-layered semi-reactive composite structure, 7 layers at angles of 30 and 60 degrees, and 3 spaced semi-reactive layers at angle of 65 degrees, to represent Abrams frontal and turret side armour.

ATGMs were tested also against composite, with addition of imitators of Western ERA, with dimensions from 250 to 500 mm.

So projectiles' design has semi-reactive effects in account, so composite structure may be less effective, relying on that effect.

 

[Damian]

Yes, but why do you think that such mechanism will work with such effectiveness against more modern projectiles ? Fact is that situation with projectiles of 70s was completely different, they were more subject to destabilisation, deformations, so it just cannot serve for making estimations.

It may be the case that many secondary effects of interaction are innefective, or even not achievable against modern APFSDS.

In fact these estimations were made already by specialists, having in account modern rounds, most modern composite armour based on principle of using energy of projectile, will not surpass equivalence with RHA in thickness, potential of semi-reactive principle is more limited than perforation growth of projectiles and their improved design.

Actually the modern APFSDS ammunition might be even more vurnable to yaw, bending and breaking due to rather high L : D ratio.

This is why Americans increased diameter in their penetrations to around 20-25mm, so penetrator is less vurnable to these defeating mechanism, other penetrations do not have this feature and have smaller diameter.

Base of composite block is mostly layer configuration, as you showed for example for hull armour, constituted 500 mm of 600-650 max.

Problem is that drawings are not completely correct and estimations based on them are mostly underestimations. I have a strong base to think that front hull armor is thicker.

This is simple example of steel plates and self forming projectile. Yes, steel hardness and space makes difference, but you should consider that composite armour is not based mostly of steel, it is lighter and there is significant space between layers, with usage of less dense material among others to achieve semi-reactive effect mainly against CE, so in fact, given

- Composition based on spaced layers
- Relation of steel to weight

Without account of semi-reactive effect (that is destabilisation of round, etc), passive protection equivalence is lower than RHA of same thickness. Account of semi-reactive effect, given it is more limited in performance against modern APFSDS, will not compensate to the point of equivalence, less to surpass it (surpass is needed to achieve protection given thickness limitation, 600-650 mm of hull armour), which is just not probable. And layered composition makes about 500 mm...

Two problems here.

1) As I mentioned, besides American penetrators that have bigger diameter and German solutions to make penetrator bend but not break, 99% of rest APFSDS ammunition, even modern is vurnable to defeating mechanisms.
2) We do not know thickness of layers and exact composition.

Yes, but it is just not representative, effect on old projectiles, and it is not valid as reference at all.

Soviet APFSDS were tested against composite block, better in characteristics than armour with effects which you describe, comparable to actual armour. So they considered semi-reactive effect Western structure, thus it will be less effective. And I would not talk about structure of modern Russian projectiles.

Increase in lenght and decrease in diameter in generall will lead to better performance against steel, but of course it would be more vulnerable to semi-reactive or reactive effect, bending, etc. So they are designed with compromises to achieve optimal performance, more complicated.

1) You do not know if Burlington variant described in sources used by Militarysta was the final version used in mass manufactured tanks.
2) You do not know if soviet armor test package was indeed better.

Important is usage of volume by armour, it may be, most likely spaced configuration not fully effective if we take as reference visible thickness.

Tarasenko conclussions are based on his belives, and are too fast, he did not seen complete armor package but only fragments of outerlayers. Long time ago I made several arguments (valid ones) against his conclussions.

This is rather funny statement. And Kontakt-V will protect against rail-gun projectiles

Seriously, it was added to increase protection against growing performance of 125 mm APFSDS and ATGM.

AFAIK some western sources said that it was intended against possible future threats from more powerfull ATGM's and armament of percived future soviet tanks like Object 477.

First, forget about ratio of 70s armour and projectiles because it is not valid.

Second, is that protection equivalence is known. It was showed with combat experience. On it's upgrade participated several companies, including NII Stali, to provide side turret protection against 500 mm perforation warheads, while they finally added simple ERA. Given CE equivalence to 400-500 mm and that it is composed mostly by layers, KE protection corresponds with stated value of more than 200 mm from normal.

Too many fast conclussion without complete data on armor packages.

Here are two types of examples, those which are speculation, and those which do not answer to statement, that composite armour does not reach equivalence with RHA in thickness against KE.

Ballistic tests on Leopard 2, and F-F incident with Challenger 2 are well known facts.

 

[Damian]

Soviet APFSDS were tested to measure performance, apart from typical 60 degree RHA element, against composite armour block.

For example in 80s they were tested against P-11 block by NII Stali. Target consisted of multi-layered semi-reactive composite structure, 7 layers at angles of 30 and 60 degrees, and 3 spaced semi-reactive layers at angle of 65 degrees, to represent Abrams frontal and turret side armour.

ATGMs were tested also against composite, with addition of imitators of Western ERA, with dimensions from 250 to 500 mm.

There are valid questions that need to be asked first.

1) What is the source.
2) To what M1 armor configuration P-11 test array was designed as comparrision mean.

 

[militarysta]

Yes, but why do you think that such mechanism will work with such effectiveness against more modern projectiles ? Fact is that situation with projectiles of 70s was completely different, they were more subject to destabilisation, deformations, so it just cannot serve for making estimations.

So I used them only to ~1986 level. - so 8 yers older then 1978 when some Burlinghton performances where describe in text about this armour.
And when we use known facts about burlington we can see some facts. I posted them erlier:

To remember:
In this two greate articles about erly Burlinghton:
http://www.wceo.wp.mil.pl/plik/file/WBBH/PH-W/PHW_4.pdf
http://www.wceo.wp.mil.pl/plik/file/WBBH/PHW3_tresc.pdf
We have some dates (with bibliography of course). In 1978 Burlinghton special armour had mass Efficiency like 1,5 vs APFSDS and 3 vs HEAT in compared to homogeneous armor steel of the same weight.
So 1kg Burlinghton armour shoud offer protection like 1,5kg homogeneous steel armor vs APFSDs and 3kg homogeneous steel armor vs HEAT (of course it is only example).
But it;s not the poit.
Most important: In russian article are given values whit relatio 1:1,27, but in article about burlinghton we have some facts based on found documents in UK:
In middle 1970 there was dependence between protection against APFSDS and HEAT
430 and 585mm RHA (1 to 1,36), but Increased armour protection against HEAT to 850mm RHA resulted with a decrease in armour protection vs APFSDS to "only" 405mm (1 to 2.09)

So relatio in this article is incorrect when we consider knowed facts about burlinghton form middle 1970.
So there are two options for M1A2:
a) 1:1,36 ratio:
vs KE - 500-550mm RHA
vs CE - 680 -750mm RHA

b) 1: 2.09 ratio:
vs KE - 500-550mm RHA
vs CE -1050-1150mm RHA

IMHO first option is more possible (500-550 vs KE, 680-750 vs CE), and means that M1A1 was safe against 3BM42 on bigger then 600-800m distance, and against 3BM32 on bigger then 1000m distance. Fr the other side when we consider fact thats SC warhed must have +150mm RHA perforation more then armour level (to kill crew or ignit ammo) then M1A1 can widstand HEAT warhed with perforation at least 830-900mm RHA
Quite impressive when we consider that those estimatous and base on relatio for Burlinghton armour from decade earlier then M1A1....

In fact Leppard-2A4 armour can give protection not in 1:2.09 ratio but in 1:1.36 ratio. In that case it will be ex:
540mm RHA vs APFSDS and ~740mm vs HEAT
It's really interesting becouse in "orgins of the burlinghton" those ratio was given

(...)

I know for erly Leopard-2A4 gun mantled mask volumen, armour weight and others. And what?
Dimensions leopard-2 gun mantled mask are known, the same dimensions of blanks for L-44, FERO, and MG. And we know mass of gun mantled mask - 630kg. Rest is rather simple math base on qustion- how thick will be homogeneous steel armor block "inside" gun mask dimensions if it will be weight 950kg (630kg x1,5 vs APFSDS) and 1890kg (630kg x3 ve HEAT). The answer is:
a) 272 mm
b) 542 mm

So this protection offer by gun mantled mask should be:
a) 270 mm vs APFSDS
b) 540 mm vs HEAT
For 42cm thick gun mantled mask -it's weight (630kg) is only 7% whole leopard-2A4 turret "special armour" (8900kg)!
And try to consider if double thick (84cm) front armour on turret can be as 540mm vs RHA and 1084mm vs HEAT - becouse mass is fully posible in that volumen like in Leopard-2A4 turret. And if you have any doubt if so hight protection level against HEAT was avaible then go back to the article and ratio between KE and CE protection. Secon value was 1: 2,09 and as we can see -it's fully possible for leopard-2A4. For lower ratio mentioned in article for 1978r it was 1: 1.36 so protection can be like 540mm RHA and ~750mm vs HEAT as lower values.
And propably ineffectiveness Soviet HEAT warhed was reson why thre was rapid growth penetartion possibilities soviet AT weapons in late 80s -and it's very easy how APFSDS and HEAt warhed developers try to catch up the growth of armor protection:

Leo2A1; 1979- november 1984
380 (I batch) + 450 (II batch) + 300 (IIIbatch)

APFSDS since 1976 to 1984.
115mm:
3БМ28 - 380mm RHA
ЗБМ21 - 330mm RHA
125mm:
3BM22 (1976) - 380mm RHA
3БМ26 (1982) - 410mm RHA
3БМ-29(1983) - 430mm RHA

ATGM's, and GLATGM's:
9М 111-2(Fagot -1975) - 460mm RHA
Konkurs (1974) - 600mm RHA
9М111М (Fagot 1983) - 600mm RHA
9М112М (Kobra GLATGM ppk 1976) - 600mm RHA
9M112M (mod. Kobry from 1985) - do 700mm RHA

In this period propably Soviet inteligence haven't bigger idea about burlinghton - perforation level enought for APFSDs was around 450mm RHA (for typical 1300m max fire range) and for HEAT warhed about 600mm RHA (-150mm RHA up armor level necessary to kill tank) so 450-500mm RHA vs HEAT.
That protection level was expected by Soviet developers. But it was propably very underestimated against HEAT wathed (different specificity Burlihton armour then all older armours) -for the other side - protection level vs KE is in accordance with the fact what we know aboit erly M1 and Leopard-2 armour.

But propably after ~1984 some infos went to the east and we can see very fast and huge growth penetartion possibilities for Soviet AT weapons -the same we can assume that soviet developes finds how really good was Burlinghton armour and they try to catch up those problem after miss a of them:

Leo2A3;december 1984-december 1985
300 (IV batch)
Leo2A4; december 1985-marc 1992
370 (1985-1987 marc; V batch)
150 (1986-1989may; VI batch)
100 (1989-1990 april;VII batch)
75 (january 1991-marc 1992; VIII batch)

APFSDS since 1985 to 1990:
3BM32 (1985) 500mm RHA
3BM42 (1986) 450mm RHA
3BM48 (1990) 600mm RHA

ATGMs and GLATGM's since 1985 to 1994:
9M120 (1985) 800-950mm RHA
Wichr-M (1990) 1000mm RHA
9M115-2 (1992) 980mm RHA
9M133-1 (1994) 1200mm RHA

In that level on typical distance in western europe soviet developers suspected to find western tanks whit about more then ~550mm RHA vs KE and more then 850-1000mm RHA vs HEAT.
Hmm it looks that those value looks simillar to thats values:
??
All is connect with each other - knowing leopard-2A4 (erly) mass and Burlinghton evectivness, Soviet AT weapons perforation etc.

And If we consider angle and LOS thickness then protection for that Leopard2A3 and 2A4 (erly) will be as ~430-480-540mm vs KE and 850-954-1084mm vs HEAT (turret sides at 30. and hull front - turret front ad 30. - turret front at 0.)
For 2A4 since 1986 it will be slighty bigger:
500-550-630mm vs KE and -1000-1150-1300mm vs CE ((turret sides at 30. and hull front - turret front ad 30. - turret front at 0.)

And If you think that more then 1300mm vs HEAT was impossible then remember about case when AGM114 hit M1A1HA turret during ODS. SC warhed whit perforation bigger then 1100mm (170mm diamtere x 6,5) was unnable to perforate those armour.
In 1991.

It may be the case that many secondary effects of interaction are innefective, or even not achievable against modern APFSDS.

Yeah -but test whit M322 on Leo-2A5 nacked (without wedges) shown smth. diffrent... the same DM43 on Leo-2A4.
Burlinghton whas hight effective againts APFSDS.

In fact these estimations were made already by specialists,

Russian ones?
C'mon - most of them are made for marketing reson or fratricidal fight between russian and ukrainian industry.
Remember those patetick article about Leopard-2A4 vs T-64 Bułat on btvt? Tarasenko wrote that shit during rywalization between second hand Leo-2A4 and Bulat in southern Asia.

Base of composite block is mostly layer configuration, as you showed for example for hull armour, constituted 500 mm of 600-650 max.

Well it this what I estimatous based on known fact about Burlinghton in 1978. And known test on leo-2A4. In reality it can be better. I just give smallest possible values.

This is simple example of steel plates and self forming projectile. Yes, steel hardness and space makes difference, but you should consider that composite armour is not based mostly of steel, it is lighter and there is significant space between layers, with usage of less dense material among others to achieve semi-reactive effect mainly against CE, so in fact, given

Not exatly - eacht know burlinghton layers looks the same: RHA plate + smth between + RHA plate or others so more or less big part of this armou is made from HHS steel thin plates. Look again at those M1A2 side armour on photo.
And those active reaction can be (and is) in resule better then "non used space" between layers.

Without account of semi-reactive effect (that is destabilisation of round, etc), passive protection equivalence is lower than RHA of same thickness.

But it's bigger due to using HHS plates than cast steel turrets in soviet tanks. As I mentioned - even 80mm thin stack HHS plates whit hight HB will be like ~200mm cast steel...
But it's not the point -we can't separate semi-reactive effect for armour.

Account of semi-reactive effect, given it is more limited in performance against modern APFSDS, will not compensate to the point of equivalence,

It's limitetd due to what? And You claim that passive armour or RHA plates are better aganst modern APFSDS then semi-active armour?
fascinating...

Those examples do not serve to explain how composite armour in thickness can be equivalent to RHA against APFSDS.

Well they are some facts...as I mentioned:
40mm HHS + 60cm special armour + 40mm HHS + 40mm HHS stop DM43. So 620mm armour stop APFSDS whit 560-620mm perforation.
Front Leo-2A5 turret without NERA (740-840mm LOS) was able to stop CL M322 (650mm RHA). CR-2 turret front 750-760mm LOS was able to stop (whit unkown angle...) M829A2 (650-710mm RHA) etc

It is aknowledged that semi-reactive effect (NERA) is limited in growth, and not sufficient to cause significant damage and destabilisation to modern projectile.

And in KWS program between 1989-1994 exatly NERA modules where developed. The same in M1A2 side armour they are NERA layers. So armour developers have diffrent opinnion then You.
In fact NERA modules are sufficien vs KE - and developers in Ge and USA are consider in that solution.

Soviet APFSDS were tested against composite block, better in characteristics than armour with effects which you describe, comparable to actual armour. So they considered semi-reactive effect Western structure, thus it will be less effective.

Hmm known armour in T-72B and T-80U is is not " better in characteristics" so about what are You talking?

And I would not talk about structure of modern Russian projectiles.

Becouse? They are very modern and wery western in style ;-)
Composite sabot, L ratio like in DM53, monoblock penetrator whit big L: D ratio. In fact between 1990-2010 this round are very simmilar to western ronds. So erlier way where not enought (BM32, BM42).

It will be less effective than steel of same thickness against APFSDS.

Hmm known NERA modules have bigger efectivness then steel and the same thickness. ERA -the same (and bigger), SLERA- again. In fact all active and semi-acive solutions had better efectivenss then steel at the same thickness.
So mayby slighty less active Burlinghton, but whit 3 main working mehanism in the same time will be simmilar?
Do you consider that?

This is rather funny statement. And Kontakt-V will protect against rail-gun projectiles

Oh really? As I rememer in both - German and Russian articles perfromances modern Sniviets-1/2 and DM53/63 roud are the same like non-existing developed in 1980. erly 140 and 152mm rounds...
So maybe it's not so strange statsment?
Maybe Methos can wrote more about KWS and German sources about KWS.

Seriously, it was added to increase protection against growing performance of 125 mm APFSDS and ATGM.

Yes it's true -but in the same times KWS program was developed against bigger thread - erly 140 adn 152mm rounds.
And If you will read articles about modern now APFSDS then You will see that in ost of them peformances now modern round: M829A3, DM53/63, Snivets, Cl M338 are given like for never-exist erly 140/152mm ammo.

First, forget about ratio of 70s armour and projectiles because it is not valid.

Why? Even using them I shown that most of those all estimatous used on wladimir, btvt and others are bullshit when relato between KE and CE protection is not OK. it's therribly underestimated.
Used known fact about erly eopard-2A4 armour mass and gun mantled mask I shown that this tank prtotection just must be better then whole estern sources claimd.
So using those ratio have sens. For 1980-1990 period of course.

Second, is that protection equivalence is known. It was showed with combat experience. On it's upgrade participated several companies, including NII Stali, to provide side turret protection against 500 mm perforation warheads, while they finally added simple ERA. Given CE equivalence to 400-500 mm and that it is composed mostly by layers, KE protection corresponds with stated value of more than 200 mm from normal.

When You consider known fact from Iraq about M1A2 sides at 90 it's bullshit. Sorry.

 

[hest]

So I used them only to ~1986 level. - so 8 yers older then 1978 when some Burlinghton performances where describe in text about this armour.
And when we use known facts about burlington we can see some facts. I posted them erlier:

Getting values from 1978 armour and projectiles and using them out of their context is just wrong !! Perhaps I should take Kontakt-5 performance against "Zakolka" and apply it to DM-53 ??

Yeah -but test whit M322 on Leo-2A5 nacked (without wedges) shown smth. diffrent... the same DM43 on Leo-2A4.
Burlinghton whas hight effective againts APFSDS.

You are taking as example test of APFSDS with nominal penetration value significantly lower than armour thickness of turret.

There is situation, hull side of 600-650 mm, so again, show me that composite armour will protect against APFSDS with perforation value higher than it's thickness (Today when average perforation value is more than 700 mm). Composite armour does not surpass equivalence with RHA.

Russian ones?
C'mon - most of them are made for marketing reson or fratricidal fight between russian and ukrainian industry.
Remember those patetick article about Leopard-2A4 vs T-64 Bułat on btvt? Tarasenko wrote that shit during rywalization between second hand Leo-2A4 and Bulat in southern Asia.

Institutes, and not only. In fact it is supported by usage of reactive armour, and addition of NERA wedges on Western tanks as Leopard.

That is, unless you believe in unrealistic values.

But it's bigger due to using HHS plates than cast steel turrets in soviet tanks. As I mentioned - even 80mm thin stack HHS plates whit hight HB will be like ~200mm cast steel...
But it's not the point -we can't separate semi-reactive effect for armour.

Fact is that you cannot talk about steel when you have configuration of spaced layers whose steel in relation to thickness is minority.

It's limitetd due to what? And You claim that passive armour or RHA plates are better aganst modern APFSDS then semi-active armour?
fascinating...

RHA is more reliable indicator of KE protection.

And in KWS program between 1989-1994 exatly NERA modules where developed. The same in M1A2 side armour they are NERA layers. So armour developers have diffrent opinnion then You.
In fact NERA modules are sufficien vs KE - and developers in Ge and USA are consider in that solution.

NERA wedges are mounted with significant space to achieve destabilisation effect before interacting with composite armour, it is different function, similar to ERA, but more limited effect against KE (relatively).

It also proves fact that just composite block is insufficient.[/QUOTE]

 

[Damian]

Getting values from 1978 armour and projectiles and using them out of their context is just wrong !! Perhaps I should take Kontakt-5 performance against "Zakolka" and apply it to DM-53 ??

I think You do not understand the point. The point is that Burlington from the very beggining had good protection characteristics against KE ammunitions, and that through it's further evolution and with later armor designs that replaced Burlington, these values are still very good, sufficent to protect against all current KE ammunition.

This is the point, not that the original Burlington can protect against modern ammunition. Now You understand?

You are taking as example test of APFSDS with nominal penetration value significantly lower than armour thickness of turret.

There is situation, hull side of 600-650 mm, so again, show me that composite armour will protect against APFSDS with perforation value higher than it's thickness (Today when average perforation value is more than 700 mm). Composite armour does not surpass equivalence with RHA.

Show me any RHA armor that will protect against modern APFSDS ammunition, and that can be placed on vehicle.

Institutes, and not only. In fact it is supported by usage of reactive armour, and addition of NERA wedges on Western tanks as Leopard.

That is, unless you believe in unrealistic values.

Why unrealistic values? Besides this we can also call values for T-xx series as unrealistic? Why we should not?

Fact is that you cannot talk about steel when you have configuration of spaced layers whose steel in relation to thickness is minority.

Ah but You do not know how thick are plates, You do not know the exact configuration of the frontal armor. You just now base only on your faith.

RHA is more reliable indicator of KE protection.

Not for composite armor.

NERA wedges are mounted with significant space to achieve destabilisation effect before interacting with composite armour, it is different function, similar to ERA, but more limited effect against KE (relatively).

It also proves fact that just composite block is insufficient.

There is no reason to belive that advanced NERA will be less efficent than ERA. Neither it proves that composite block alone is insufficent. Especially that most countries actually do not use any addon armor, but just improves base armor.

We can also made a point towards controversiall theory.

Perhaps some designers were capable to design better composite armor that offer better protection on it's own, other were unable or unwilling to do so because of significant weight increase as an example, thus they opted for lighter addon armors in form of ERA or outer NERA.

Simple, controversiall, yes indeed, but not immposible.

 

[methos]

Yeah -but test whit M322 on Leo-2A5 nacked (without wedges) shown smth. diffrent... the same DM43 on Leo-2A4.
Burlinghton whas hight effective againts APFSDS.

Not really. It depends on how much you exactly know about the German tests and how much is your/our theory. For example do we know when these tests were made? Is this the real 120 mm DM 43A1 ammunition (which in my opinion penetrates more than 600 mm RHA at 2,000 m) or just a development stage (DM 43 was qualified in 1996)? Do you really know that the 10 cm thick steel layers had a hardness of only 220 HB or is this part of your theory about it's design? Do you know that the steel plates used to replace them have a thickness of 40 mm or could it be 50 - 60 mm? Are there single steel plates or layered steel plates with a total thickness of 40 - 60 mm?
The 120 mm DM43 penetrated the whole special armour box (50 cm according to you) and more than two steel layers (10 cm each) with partial perforation into a third one. There is a huge difference between mass efficiency and thickness efficiency. If they used "soft" steel (like 200 - 220 HB), then the total equivalency of ~25 cm steel with a hardness of 200 -220 HB would still offer protection somewhere around 200 mm RHAe. Then the 50 cm "special armour" would be equivalent to some ~400 mm RHAe (assuming 600 mm perforation). That would be pretty good... but if the steel would be "normal RHA", then the "special armour" would only have a protection of ~300 mm RHAe on it's own (for armour used in 1988 - 1989). 300 mm RHA could be replaced by some more advanced triple hardness steel (THS) on the production model, i.e. the Leclerc's THS is said to offer 1.78 times as much protection than RHA (for armour used first in 1992), so the Leopard 2A4 might feature THS in the armour with a EM and TE of 1.65 - 1.75.
So three 50 - 60 mm thick triple hardness steel layers would be effective enough to offer 300 mm RHAe protection.

If you can clarify something about the tests (e.g. steel hardness, exact thickness or type of ammo used [prototype or real ammo]), then please post it.

We also have no clue what hardness is used as reference when it comes to RHAe values. Some people on TankNet for example calculate armour penetration values with 230 - 235 HB steel, which is less than the average Soviet tank used. I prefer 270 HB, because this is said to be the hardness of the Soviet cast armour used on the turrets. The real definition of RHA (MIL-something) in the U.S. does not specify a general hardness but makes it depending on thickness - thicker armour, less hardness (as done in WW2). Also the U.S. changed their steel composition for the M60A1/M60A3 tank after 1973 according to TankNet.

What I also find important is the question "what is Burlington". Yes, this might sound a little bit funny at the first moment but: Does Burlington or "Chobham" really refer to the whole armour layout or just to a single part (e.g. the special armour box)? I doubt that "Burlington" generally means "NERA + THS + ceramics + polymere". I mean look at some British tanks: Chieftain 900, FV4211, MBT80 (ATR1 & ATR2), etc. all had cast steel turrets just with boxes of special armour fitted to them... does this boxes really contain "NERA + THS + ceramics + polyemere" or do they just contain parts (i.e. NERA). The Warrior IFV when fitted with "Chobham" (at least C. Foss calls it "Chobham") does probably not have THS in the boxes - the Polish guy who wrote the article (the one with the name impossible to remember for me) assumed that they would only use NERA there.
The Challenger 1 and 2 also have a imo thick cast steel turret, then some "special armour boxes" and then further steel bolted to the front (implying THS) - can we be sure that the boxes contain "NERA + THS + ceramics + polymere" or do they contain less?
The Valiant and Vickers Mk.7, both tanks made without cast turrets however do not feature the outer two steel layers of the Challenger 1 and 2 - IMO this could imply that the Valiant and Vickers Mk. 7 use THS inside the armour, while the Challenger 1 and 2 do not have it inside the armour boxes. But who nows.
I think speaking about Burlington (developed in the 1970s) and then refer to more complex arrays like that of the M1A1HA or the Leopard 2A4 (both tanks made after 1988) is somehow faulty. Maybe Burlington is only a part of the modern tank armour and not a general layout utilizing multiple elements. German sources, although all use different terms to refer to the Leopard 2 armour, sometimes speak about the Leopard 2 armour as hybrid between Schotttpanzerung and Verbundpanzerung.
Maybe the early Leopard 2, M1 and Challenger 1 had far less complex armour than today's tanks?

It's limitetd due to what? And You claim that passive armour or RHA plates are better aganst modern APFSDS then semi-active armour?

Per thickness it is less effective against APFSDS than RHA or layered steel without gaps. It depends on how the armour exactly looks - if they use ductile steel, with a type of very energetic rubber in the best possible layout (meaning the NERA sandwiches are aligned at different angles), then the amount of air/empty space inbetween the sandwich plates is very big. If they use just simple steel/rubber/steel sandwiches with rather thick layers of harder, less ductile steel, with all layers paralell, then the space will be smaller (but the armour will be less effective per weight).

 

[Damian]

What I also find important is the question "what is Burlington". Yes, this might sound a little bit funny at the first moment but: Does Burlington or "Chobham" really refer to the whole armour layout or just to a single part (e.g. the special armour box)? I doubt that "Burlington" generally means "NERA + THS + ceramics + polymere". I mean look at some British tanks: Chieftain 900, FV4211, MBT80 (ATR1 & ATR2), etc. all had cast steel turrets just with boxes of special armour fitted to them... does this boxes really contain "NERA + THS + ceramics + polyemere" or do they just contain parts (i.e. NERA). The Warrior IFV when fitted with "Chobham" (at least C. Foss calls it "Chobham") does probably not have THS in the boxes - the Polish guy who wrote the article (the one with the name impossible to remember for me) assumed that they would only use NERA there.
The Challenger 1 and 2 also have a imo thick cast steel turret, then some "special armour boxes" and then further steel bolted to the front (implying THS) - can we be sure that the boxes contain "NERA + THS + ceramics + polymere" or do they contain less?
The Valiant and Vickers Mk.7, both tanks made without cast turrets however do not feature the outer two steel layers of the Challenger 1 and 2 - IMO this could imply that the Valiant and Vickers Mk. 7 use THS inside the armour, while the Challenger 1 and 2 do not have it inside the armour boxes. But who nows.
I think speaking about Burlington (developed in the 1970s) and then refer to more complex arrays like that of the M1A1HA or the Leopard 2A4 (both tanks made after 1988) is somehow faulty. Maybe Burlington is only a part of the modern tank armour and not a general layout utilizing multiple elements. German sources, although all use different terms to refer to the Leopard 2 armour, sometimes speak about the Leopard 2 armour as hybrid between Schotttpanzerung and Verbundpanzerung.
Maybe the early Leopard 2, M1 and Challenger 1 had far less complex armour than today's tanks?

Good question.

The problem is that the armor itself do not have any codename in reality, it is just caled Burlington or Chobham for ease, while Burlington reffers to the whole armor research and development program codename.

Przezdziecki wrote that in documents under that program not a single type of armor was developed, but plenty of different types, from spaced to NERA like arrays and even build in ERA.

The whole problem just makes to be more and more complex when some new facts are found in declassified documents.

Hmmm, perhaps the special armor array is like the Germans describe it, a hybrid armor with part of the layers as NERA like array and part thicker, densier and more passive? The question is also what % of armor in such configuration could be NERA and what % would be more passive?

It is hard to say without actually seeing complete documentation and photographs of armor arrays.

 

[hest]

US Army Awards GD $395 M to Begin Engineering Development for Abrams Modernization

A steady and conservative modernisation approach to 2020.

 

[Damian]

Good, weight reduction by redesigning electronics and mechanical components, and survivability improvements in armor.

The interesting thing is they mention ECP1, I had somewhere or seen somewhere, that it was mentioned in documents, it also means possible further ECP versions in future.

Well hopefully we will see new M1 version technology demonstrator soon.

A steady and conservative modernisation approach to 2020.

We will see. I would rather be very careful with any opinions before any photos or even graphics/drawings of the new version will be officialy presented.

Besides this, it is only ECP1, there might be ECP2 and so on. I think that they are currently focusing on the most important aspects, that are needed to be solved, it means redesigning internal components of tank, and improving protection, any further improvements are actually solved, L3 company offer allready with GDLS new suspension and powerpack for M1, that can be installed even on currently existing variants.

However as I said, let's wait to the first official presentation of the vehicle, before making any too far ahead conclusions. I'am really interested if they will change the outer apparance of the vehicle.

Also in fact such steady and conservative upgrades are very normal. T-90MS for example, there was nothing radical in the upgrades, T-84M, the same pattern, Leopard 2A7, also.

And I think that considering todays economical problems, it is a good approach to the problem of upgrading tanks before the next generation will be ready.

 

[Damian]

An M1A1 Main Battle Tank fires from its main gun Sept. 26 during a practice shoot for the 2012 Tiger Competition aboard Camp Lejeune. The next day, a crew from 2nd Tank Battalion, 2nd Marine Division, consisting of Sgt. Linh Ngo, tank commander; Cpl. Ryan Hanna, gunner; Lance Cpl. Delio Linares, loader; and Lance Cpl. Domenic Kalaski, driver, defeated crews from 1st Tank Battalion and 4th Tank Battalion to win the tournament and capture the Gunnery Sergeant Robert H. McCard Cup.

This is probably the first photograph of modernized USMC M1A1 with new commander cupola SCWS.

Below, Idaho ARNG unit recive it's new M1A2SEP v2's.

Idaho National Guard senior leaders examined and fired the new M1A2 Abrams tank with system enhancement package version 2 at the Orchard Combat Training Center south of Boise, Idaho, Sept. 27. The 116th Cavalry Brigade Combat Team received the new weapons systems earlier this summer making it the first fully-modernized Army National Guard unit in the country.
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Idaho Maj. Gen. Gary Sayler, adjutant general, sits in the M1A2 Abrams tank with system enhancement package version 2 at the Orchard Combat Training Center south of Boise, Idaho, Sept. 27. The general and other command staff spent the day learning and testing the capabilities of the latest in armored weaponry. The 116th Cavalry Brigade Combat Team received the new weapons systems earlier this summer making it the first fully-modernized Army National Guard unit in the country.

 

[313230]

I wonder how a normal bomb would do to a tank, e.g a 250kg one? How much RHA is needed to survive such an explosion?

 

[Damian]

I wonder how a normal bomb would do to a tank, e.g a 250kg one? How much RHA is needed to survive such an explosion?

It depends where it explodes. If under a tank, and tank do not have additional belly protection, then there is more than probabale that belly plate will break and interior will be massacred.

If at side of a tank, most probably only suspension, tracks, all vehicle components outside will be damaged or destroyed, but crew will survive.

And messuring protection against bombs or big explosive devices in RHA is a misunderstanding, nobody do that.

 

[Damian]

I wonder how a normal bomb would do to a tank, e.g a 250kg one? How much RHA is needed to survive such an explosion?

It depends where it explodes. If under a tank, and tank do not have additional belly protection, then there is more than probabale that belly plate will break and interior will be massacred.

If at side of a tank, most probably only suspension, tracks, all vehicle components outside will be damaged or destroyed, but crew will survive.

And messuring protection against bombs or big explosive devices in RHA is a misunderstanding, nobody do that.

 

[methos]

A 250 kg IED will take out even a tank with additional anti-mine protection like a M1 with TUSK or a Leopard 2A6M. When dropped from an airplane a 250 kg bomb has enough kinetic energy to overcome any type of current roof armour, while the explosion itself could be survived by tanks with thick roof armour.

 

[militarysta]

Not really. It depends on how much you exactly know about the German tests and how much is your/our theory. For example do we know when these tests were made? Is this the real 120 mm DM 43A1 ammunition (which in my opinion penetrates more than 600 mm RHA at 2,000 m) or just a development stage (DM 43 was qualified in 1996)? Do you really know that the 10 cm thick steel layers had a hardness of only 220 HB or is this part of your theory about it's design? Do you know that the steel plates used to replace them have a thickness of 40 mm or could it be 50 - 60 mm? Are there single steel plates or layered steel plates with a total thickness of 40 - 60 mm?

Methos, some infos are unpossible to given on public forum. Other ones can be given:

1. in 90s' but until 1996
2. almoust sure in development stage
3. tomato
4. yes, 40mm
5. 1 plate 40mm + "special armour" + 2 plates.

The 120 mm DM43 penetrated the whole special armour box (50 cm according to you) and more than two steel layers (10 cm each) with partial perforation into a third one. There is a huge difference between mass efficiency and thickness efficiency. If they used "soft" steel (like 200 - 220 HB), then the total equivalency of ~25 cm steel with a hardness of 200 -220 HB would still offer protection somewhere around 200 mm RHAe. Then the 50 cm "special armour" would be equivalent to some ~400 mm RHAe (assuming 600 mm perforation). That would be pretty good... but if the steel would be "normal RHA"

What I know: "late 2A4 armour model, whit minor changes in steel plates due to financial reasons". As I understand - cheaper steel plates where used whit smaller HB but thicker to achive protection. And it was not armour test but amunitions.

We also have no clue what hardness is used as reference when it comes to RHAe values. Some people on TankNet for example calculate armour penetration values with 230 - 235 HB steel, which is less than the average Soviet tank used. I prefer 270 HB, because this is said to be the hardness of the Soviet cast armour used on the turrets.

The best example You have in WITU material - they use not NATO methodlogy but taken from WarPac and CCCP. So DM33A1 had guaranteed only 470mm RHA at 2000m and DM43 only 560mm RHA at 2000m. Using NATO norm both rounds have mucht better performances (DM33 more then 500 and DM43 more then 600).

Does Burlington or "Chobham" really refer to the whole armour layout or just to a single part (e.g. the special armour box)

Well I think it's rather only single part of armour then whole part. But on the other hand - some known working mehanism in Burlinghton are possible for more known layers not only "spacial armour box".

assumed that they would only use NERA there.

not exatly. There is problem about ideas " how Germans came to special armour".

I think speaking about Burlington (developed in the 1970s) and then refer to more complex arrays like that of the M1A1HA or the Leopard 2A4 (both tanks made after 1988) is somehow faulty

Well I use them only to show that 90% russian estimateus are taken from space and using known fact about erly Leo2A4 Vol. armour mass, part armour mass, thickenss, and data about Burlinghton efectivness in 1978 I show that protection (especially against CE) just must be bigger then most "sources" on est claim now. And what is funny -when ussaly protection against APFSDS is (IMHO) given more or less good then protection against HEAT is highly underestimated.

Maybe Burlington is only a part of the modern tank armour and not a general layout utilizing multiple elements.

good question.
On LKE I test those "late 2A4 armour model" had only ~50cm "special armour" rest- ~34-36cm is passive protection.
Photos whit open M1A1 sides shown that about 60-70% is semi-active "sandwich" and rest are conventional passive plates.
Merkava Mk.IV had whole modules semi-active and pasive only 5-8cm thick inner plate (citadele).

But I have strong doubts -what if only whole armour work using those 3 known mehanism? (plate blending, whistle effect, debrits).


Damian

Hmmm, perhaps the special armor array is like the Germans describe it, a hybrid armor with part of the layers as NERA like array and part thicker, densier and more passive? The question is also what % of armor in such configuration could be NERA and what % would be more passive?

I's simple:
50cm active
34-36cm passive
or this what I take as passive is active

 

[313230]

Thank Damian and methos,

Modern armor is designed to concentrate on small area impact. A bomb maybe cant penetrate front armor by penetration ability but can shake the whole tank or break the armor structure in a different manner. From some pictures of very big IEDs, even the turret was blown but it seemed the structure was not much damaged. Bomb is not a dedicated anti tank, so its penetration is limited, but what I want to discuss is the ability to resist a big explosion like that. Any estimate how thick armor is needed to overcome a bomb? Is there any major difference in concept of protection against big explosion like HE vs KE?

My guess, submarine at deep sea may has more than ten centimeters of steel to resist pressure, a bomb's pressure is much higher than that and shrapnel travels at high speed, several km/s. Maybe several dm of steel?

Regards

 

[Damian]

As far as I know the biggest problem is not possible penetration of thinner armor, it was overcome by installing addon armor for the belly of the hull.

The problem is what happens with crew inside, in reality IED does not even need to damage or destroy vehicle, but can hurt a crew, this is very problematic.

 

[Damian]

Perhaps a bit different kind of information.

Few days ago to my country, Poland, arrived two tanks for museum of the ground forces in Poznan. These are M48A5 and M60A1 that were withdrawn from service in the Greek armed forces. Tanks are fully operational and in very good shape.

Videos:

 

[militarysta]

TF I ask:

მოკლე ანალიზი ოპერაცია ,,თავისუფლება ერაყს 2003''- ში ჯავშანტექნიკის გამოყენებაზე.
....

(yes -my small provocation Damian "love" that stuff)