Main Battle Tanks and Armour Technology

[militarysta]

It's looks like this but error margin is 10% so eacht value I incerese on about 15%
Repeat: eacht LOS tchickness I incarase on 15% to reduce error (it's better to overestimated then understimated).

And I don't buy Chneese desingne MBT"s.

In thicker part LOS is pretty good - <940mm LOS, but rest turret have "Merkava illnes" and LOS is therrible small - smaller then on Russian tanks - in fact upper half of turret hight hae LOS under <650mm.

And I have doubt if chineese ERA is even in half good as Relikt. I doubt.

 

[methos]

Glacis plate - 50m@80-82 degrees = ~300mm + fuel tanks = ~200mm + additional 5 plates inside fuel tanks, each 50mm@10 degrees from horizontal = ~287mm protection for each plate, then You can achieve... 1,935mm of protection equivalent! It is a bit insane, but possible and should not add too much weight.

You mixed up angles. If the outer glacis is 50 mm at 80 - 82°, then the inner 50 mm plate at 10° should offer protection equivalent to 50.7 mm (nearly no increase in performance). I doubt that the M1 does have such a armour structure inside the fuel tanks, because the projected weight limit lead to at least two redesigns during development. Your figures would probably increase the armour weight by 60 to 150 % compared to the Burlington armour.

 

[Damian]

Meanwhile in Turkey.

 

[Damian]

You mixed up angles. If the outer glacis is 50 mm at 80 - 82°, then the inner 50 mm plate at 10° should offer protection equivalent to 50.7 mm (nearly no increase in performance). I doubt that the M1 does have such a armour structure inside the fuel tanks, because the projected weight limit lead to at least two redesigns during development. Your figures would probably increase the armour weight by 60 to 150 % compared to the Burlington armour.

It is because this damn calculator (Relative armour thickness calculator).

And guess what, there were actually at least two redesigns of hull during development phase of the XM1/M1. You can see it on drawings and photos in Hunnicutt book where front hull section was changed.


Early prototype and production vehicle, both turret and hull designs changed significantly. My theory is then not unreasonable, and high protection levels can be achieved against both KE and CE threats for glacis plate.

 

[methos]

Early prototype and production vehicle, both turret and hull designs changed significantly. My theory is then not unreasonable, and high protection levels can be achieved against both KE and CE threats for glacis plate.

The high protection level is only achieved by a very high weight. It is not very mass-effective armour.

 

[Damian]

The high protection level is only achieved by a very high weight. It is not very mass-effective armour.

There is allways something for something, there are no perfect solutions. Still Dr. Gilbert Harvey tested such armor configuration for light tanks with great success, and Americans achieved full access to all developments. We should remember that Burlington was not developed from ceramics research and development but spaced armor and fuel tanks as armor applications R&D programs. Also the whole concept of M1 front hull fuel tanks as encased in separated compartments suggests that the armor structure there do not only use fuel as additional protection, but the whole array is close to spaced armor arrangement.

Another problem is that we do not know what weight americans provide for their tanks, if this is dry weight or combat loaded weight.

 

[militarysta]

(link to the same picture: ImageShack� - Online Photo and Video Hosting)

Very interesting part of bigger article from NII Stali about ERA, NERA and NxRA. I placed on the picture parts whit jet shape after countr-working.

But here is one small missunderstand - I haven't idea what kind of "NERA" is present in those article -propably very simple reflecting plate - but it's performances looks even whorse then very simple NERA tested in western europe (I gave results erlyier). In fact those picture have nothing common whit modern NERA panels used on west. That kind of modern NERA (or NxRA) are show the last set of pictures.
Anyone can compare the results for german double NERA(or NxRA too) module and for new russian NxRA. Time is almoust the same 90 vs 100 and 200 vs 194.7 Only questionable part is used SC warhed. In Germans test it was 136mm CD and 950mm RHA perforation.

And maybe Im blind but I can't see single one advance russian NxRA in compare to the german NERA/NxRA. In fact photos shown that single NxRA is less effective (what is obvious) then doubble module.
But if german double module have CP= >91% (in fact around 95%) then russian double NxRA should have simmilar performance. And it's really interesting becouse agianst tandem warhed those russian NxRA works like 500mm RHA.

 

[hest]

Very interesting part of bigger article from NII Stali about ERA, NERA and NxRA. I placed on the picture parts whit jet shape after countr-working.

But here is one small missunderstand - I haven't idea what kind of "NERA" is present in those article -propably very simple reflecting plate - but it's performances looks even whorse then very simple NERA tested in western europe (I gave results erlyier). In fact those picture have nothing common whit modern NERA panels used on west. That kind of modern NERA (or NxRA) are show the last set of pictures.
Anyone can compare the results for german double NERA(or NxRA too) module and for new russian NxRA. Time is almoust the same 90 vs 100 and 200 vs 194.7 Only questionable part is used SC warhed. In Germans test it was 136mm CD and 950mm RHA perforation.

In article there is comparison of different types of armour for lightly armoured vehicles contrasting protection and safety. Thus NERA, ERA and NxRA are compared with same circumstances (dimension, mounting arrangement).

They have similar thickness and they are tested against same warhead at same angle of incidence. Relative performance which NERA reflects (that applies to all NERA) compared to ERA is lower, inherent consequence of working principle.

NxRA is completely different thing than NERA, as described to exploit material properties to cause reaction with greater effectiveness. It is used as part of 4S24.

And maybe Im blind but I can't see single one advance russian NxRA in compare to the german NERA/NxRA. In fact photos shown that single NxRA is less effective (what is obvious) then doubble module.
But if german double module have CP= >91% (in fact around 95%) then russian double NxRA should have simmilar performance. And it's really interesting becouse agianst tandem warhed those russian NxRA works like 500mm RHA.

No, you just made totally wrong "comparison". You show test in different conditions, with double, thicker NERA layers, and different angle, which obviously will give better result than single, thinner layer (increase number of layers how you like to get increase in performance, but it is wrong for comparison )

Problem is that there is no correct reference. For example modern ERA in same conditions will give much superior performance (thus you cannot say it is as effective) and set up of this test will not be replicated in reality as vehicle protection due to volume, arrangement limitations.

Also, how it will be against modern warhead... and what is the measuring standart.

Against tandem warhead this russian NxRA will not work as 500 mm, that is achieved with different configuration and in different way, also, NERA and NxRA are two different things.

 

[militarysta]

Thus NERA, ERA and NxRA are compared with same circumstances (dimension, mounting arrangement).
They have similar thickness and they are tested against same warhead at same angle of incidence.

The circumstances are obvious not the same in all cases. And in the article there is no sigle mentioned about "same circumstances" or smth else. Only the angle can be simmilar:
fig.7 1983; ~36 degree (or 54 if you want)
fig.8 2003; ~31degree (or ~60 if you want)
fig.9 2009; ~33 degree (or ~57 if you want)
fig.10 2009 and 2005 (or 2009) (30 degree (or 60 if you want)
and the nex only common thing can be warhed CD and nothing else, becouse even optimum detonation distance is depend on copper inside angle and CD. And the yers of tested are diffrent.
In both German NERA we have 25 degree (or 65 if You want).

Relative performance which NERA reflects (that applies to all NERA) compared to ERA is lower, inherent consequence of working principle.

Only russian NERA in this russian article have for single NERA layers whorse relative performance.
And on west nobody use single NERA layers.
As I said - in Leopard2 A5-A7 turret wedges - 2-3 NERA layers. Front hull - 2 nera layers. Only upper glastic plate have single layer -propably for slopped reson (at 83 degree).
And in this article NERA is mentioned in context "reflecting plates".

NxRA is completely different thing than NERA, as described to exploit material properties to cause reaction with greater effectiveness. It is used as part of 4S24.

1. Basic principle NERA and NxRA is simmilar. And modern NERA (IBD for example) works closer to the NxRA then older NERA. It's first problem.
2. Shape of working casette and exsplosion (or rather reactive working) in fig.10 (russina NxRA) and germans double NERA layer is almoust the same. It's obvious diffrent from ERA (fig.7 and 8) and for this weak NERA (or rather reflecting plate) from fig.9.
And when we compare rest of copper jet after NxRA and NERA working we can see that jet is more shredded and broken into small parts on germans photos. Of course it can be explain by double NERA modules, but as above we can't say that NxRA from fig.10 works better then double NERA based on IBD insert materials.

Problem is that there is no correct reference. For example modern ERA in same conditions will give much superior performance (thus you cannot say it is as effective) and set up of this test will not be replicated in reality as vehicle protection due to volume, arrangement limitations.

I doubt if single ERA casette is the same effective as double NERA module. For example at Leopard-2A5-A7 wedges. And angle of NERA on Leopard-2 famii is close to the optimum in turret front, glastic and upper glastic plate thema.

 

[militarysta]

Smth. to our Indian friends:

Inconsistent Performance of a Tandem-shaped Charge Warhead
S. Harikrishnan and K.P.S. Murthy
Armament Research and Development Establishment, Pashan, Pune -411021
ABSTRACT
Tandem shaped charge warhead is one of the efficient methods to defeat the explosive reactive armour
(ERA) protected main battle tanks (MBT). In this concept, two shaped charges mounted in the same missile
are initiated one after the other with certain time delay. First shaped charge jet would remove the ERA and
the second jet would penetrate the bare armour. Both these explosive charges are mounted close to each other
most of the time due to severe space constraints in the system. It is necessary to protect the second charge
from the blast effects of first charge, during the time delay between the initiations of two charges. Blast effect
of precursor charge on main charge is understood to have detrimental effects on the performance of warhead
system.This paper presents a case study of an investigation into the inconsistent performance of a tandem
warhead for a third generation antitank missile. The warhead generated a crooked jet resulting in inconsistent
penetration performance. Typical crater profiles were observed when the penetration performance deteriorated.

http://publications.drdo.gov.in/ojs/index.php/dsj/article/viewFile/335/196

 

[militarysta]

DEFEATING THE RPG7 THREAT BY USING ELECTRIC POWER IN REACTIVE ARMOUR APPLICATIONS
http://www.mater.upm.es/isb2007/Proceedings/PDF/Volume_2/Vol.II(35)TB87.pdf


STUDY ON TANDEM SHAPED CHARGES TECHNIQUE
http://www.mater.upm.es/isb2007/Proceedings/PDF/Volume_2/Vol.II(43)TB20.pdf

Penetration Behaviour Simulation of Shaped Charge Jets in Water Filled Targets
http://proceedings.ndia.org/1210/11910.pdf

Very good basic padf when interaction between hiht velocity penetartor (KE and CE) and moving armour parts:
http://hvis2012.org/images/uploads/HVIS2012-Agenda-2-1.9.13.12.pdf

 

[militarysta]

From "Ceramic armour" pdf about T-80 hull armour:



T-80B ?

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

pdf whit how to defeted ERA casette using non inintiating precursor:
http://ciar.org/ttk/mbt/papers/lakowski.2006-09/paper142p.pdf

Advances in Multipurpose Warhead Technology:
Hellfire Integrated Blast Fragment Sleeve (HF IBFS) Warhead
for the Hellfire R Missile System
Very interesting presentation when new Hellfire warhed is present:
http://www.dtic.mil/ndia/2011gunmissile/Tuesday11756_Thomas.pdf

 

[militarysta]

.................................................

 

[hit&run]

Have a break for few minutes,


please continue.............

 

[hest]

The circumstances are obvious not the same in all cases. And in the article there is no sigle mentioned about "same circumstances" or smth else. Only the angle can be simmilar:
fig.7 1983; ~36 degree (or 54 if you want)
fig.8 2003; ~31degree (or ~60 if you want)
fig.9 2009; ~33 degree (or ~57 if you want)
fig.10 2009 and 2005 (or 2009) (30 degree (or 60 if you want)
and the nex only common thing can be warhed CD and nothing else, becouse even optimum detonation distance is depend on copper inside angle and CD. And the yers of tested are diffrent.
In both German NERA we have 25 degree (or 65 if You want).

There is no practical difference (this is error of perspective).

Only russian NERA in this russian article have for single NERA layers whorse relative performance.
And on west nobody use single NERA layers.
As I said - in Leopard2 A5-A7 turret wedges - 2-3 NERA layers. Front hull - 2 nera layers. Only upper glastic plate have single layer -propably for slopped reson (at 83 degree).
And in this article NERA is mentioned in context "reflecting plates".

NERA in general will be worse under same conditions, because it is an inherent feature, use of energy of projectile to counter it will be less effective than energic reaction.

I do not see logic on your point. You say that bigger amount of NERA layers will give better protection than single layer, that more is needed to approximate single ERA element ? It is what your comparison tells. But if you talk about relative performance (what is better in similar conditions) you cannot say anything with your example, it is better explained in NII Stali article.

1. Basic principle NERA and NxRA is simmilar. And modern NERA (IBD for example) works closer to the NxRA then older NERA. It's first problem.
2. Shape of working casette and exsplosion (or rather reactive working) in fig.10 (russina NxRA) and germans double NERA layer is almoust the same. It's obvious diffrent from ERA (fig.7 and 8) and for this weak NERA (or rather reflecting plate) from fig.9.
And when we compare rest of copper jet after NxRA and NERA working we can see that jet is more shredded and broken into small parts on germans photos. Of course it can be explain by double NERA modules, but as above we can't say that NxRA from fig.10 works better then double NERA based on IBD insert materials.

It is not similar. NERA uses energy of projectile to defeat it, NxRA uses chemical energic reaction from material, these are two very different things and it is either one or another.

2 It is only guess and wrong comparison.

You do not know whether any reactive material is used (and it is referred as NERA...) and any deduction is incorrect because better apparent performance may be just result of bigger amount of material employed, number of layers, angle, which will say nothing about relative performance.

I doubt if single ERA casette is the same effective as double NERA module. For example at Leopard-2A5-A7 wedges. And angle of NERA on Leopard-2 famii is close to the optimum in turret front, glastic and upper glastic plate thema.

NERA needs greater amount of material, layers and space to approximate ERA in performance, it also implies that it can only be used in certain frontal parts, and cannot provide broader protection. ERA cassete placed at same angle (for example in hull) will give superior performance, howewer protection needs to be universal (KE, tandem warhead) and on this aspect advanced ERA cannot be matched.

 

[Damian]

howewer protection needs to be universal (KE, tandem warhead) and on this aspect advanced ERA cannot be matched.

The problem is that neither You, neither NII Stali understands that world do not want advanced ERA, world do not want ERA at all. ERA is just obsolete method of vehicle protection based on explosive material. Puting explosives on vehicle is a problematic issue, why even do this?

There is no future in ERA as this is just a one hit armor, neither it is capable to protect against advanced types of KE ammunition designed to defeat it.

The future is in composite armors made from very light yet very strong nanomaterials, like fullerene's or aggregated diamond nanorods (ADNR), actually these materials are the strongest materials known to humanity, stronger than diamond, besides also flexible not brittle compared to diamonds or ceramics. In some tests layers of such nanostructures proved to be capable of something we can call self regeneration.

When mass and relatively cheap production of these materials in form of plates will be possible nobody will need such obsolete protection like ERA.

And applications as armor of these materials gives incredible possibilities, imagine not only relatively light yet incredibly well protected armored fighting vehicles, but also increased survivability of ships, helicopters, planes, as well as individual soldiers.

But this is only possible in a countries where scientists and engineers do not have obsession about single type of protection method, where are people that are seeing possible future alternatives as well as there is proper financing of the R&D programs... well such country definetly is not Russia.

 

[hest]

There is no best method, just evolution

Passive - Semi active, use of energy of projectile to defeat it (NERA) - Active, use of energic reaction to defeat projectile (explosive, chemical, electric, etc)

Without release of energy it is not possible to provide sufficient protection.

Yes, in perspective there are different kinds of reactive armour than explosive, that is what you will see on future tank, atleast Russian. In terms of efficiency, explosive still gives very high performance especially in modern arrangement, higher than anything now deployed.

If you like the term obsolete, then you should apply it to NERA first, and only then to explosive reaction.

 

[Damian]

There is no best method, just evolution

Passive - Semi active, use of energy of projectile to defeat it (NERA) - Active, use of energic reaction to defeat projectile (explosive, chemical, electric, etc)

Without release of energy it is not possible to provide sufficient protection.

Yes, in perspective there are different kinds of reactive armour than explosive, that is what you will see on future tank, atleast Russian. In terms of efficiency, explosive still gives very high performance especially in modern arrangement, higher than anything now deployed.

If you like the term obsolete, then you should apply it to NERA first, and only then to explosive reaction.

ERA is obsolete, period, deal with it. NERA, not so much, mainly because of it's multihit capability.

Also if You didn't notice, I didn't say anything about reactive armors. I was talking about new materials like fullerene's or aggregated diamond nanorods (ADNR), I know that in Your country with primitive science such things are not known, but maybe read something about nano materials.

Both of these mentioned above are strongest materials known to humanity + they are also very light. When only issues with manufacturing them cheap, in hige quantities and in form of plates will be solved, most probably we will not need any sort of reactive armors, when even relatively thin armor made from these materials will provide higher protection.

Of course most probably it will still need to be encased inside a cavity made from steel plates, but there will be possibility to make it less bulky, less heavy, and just better due to characteristics of these materials.

I know that in Russia and especially Bellaruss with non existing R&D programs on nano technology it is difficult to even imagine, but today there are several countries allready working on implementation of nanotechnology in to armor making like USA, Germany, Japan, and some of them allready slowly inducting this in to service (Germany - IBD, Japan - rumors about such tech in Type 10 MBT) opelny, and some still most probably keeping it in secret (USA).

Besides this ask Yourself why none highly developed country use solutions developed in soviet union?

Argument that soviet designers were smarter is just lame. It is simple, different solutions were designed, and nobody even bothered to take the same way, besides why to stick with people that have obsession on ERA and completely ignore alternatives?

I preffer to stick with these that are aiming at making progress, not redesign for eternity obsolete solution like ERA.

 

[hest]

Re: Arjun Main Battle Tank (MBT)

As I remember You asked how mucht bigger will be penetration at almoust 0m distance in modern APFSDS rounds.
Those data are taken from official polsih 10TkBde (Leopad-2A4) data about amunition in Poland, Germany & USA, and enemy (ex Soviet). It's using during trening material so I suppose it was prepared using OPSPEC sources and others.
Data:
3BM42 -P0:580 P2500:460
DM33 -P0:600 P2500:490
M829A1 -P0:700 P2500:560

3BM42M -P0:630 P2500:510
DM53(L44) -P0:670 P2500:560
M829A2 -P0:770 P2500:660
PRONIT -P0:560 P2500:460

I wouldn't be so confident on values given in army manuals as they have "motivations" and they are not necesarily real, some of these values are higher than those of actual performance.

PRONIT has worse characteristics than Mango ?

(and T-90S as I understand) windstand about 550-560mm RHA APFSDS perfoation. It NATO circa about 1984-1986 level.

It is not correct about "NATO 1984-1986 level"

 

[Damian]

I wouldn't be so confident on values given in army manuals as they have "motivations" and they are not necesarily real, some of these values are higher than those of actual performance.

You might not belive, it does not matters, Militarysta had good sources, better than You will ever have. And this should be enough for You.

It is not correct about "NATO 1984-1986 level"

It is very correct, just accept facts that NATO in many terms due to better R&D financing, lack of stop in R&D, just left Russia behind in many things relatd to military.