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Sturgeon's House

Fucking NERA everywhere


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Just now, Sturgeon said:

Oh no, you did offend us. See, here we don't get offended by nazi memes or unpopular political opinions, we get offended by retard non-contributors coming in here swinging their dicks around and acting like their opinions are all that needs to be said.

Referte aut morimini, bitch. Opinions don't trade. Ya ken?

So when I provide sources that are unpopular, you feel offended, this is the case? Just be strait with it, or if you don't like what I post just simply ban me. Because I see where it goes, I defended the US made design, provided the sources, but all the sudden you came here, and you say I do not provide sources good enough. Ok, that's okay with me, it's your opinion, but if you do not like my contribution, simply be open about it.

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Just now, Damian said:

So when I provide sources that are unpopular, you feel offended, this is the case? Just be strait with it, or if you don't like what I post just simply ban me. Because I see where it goes, I defended the US made design, provided the sources, but all the sudden you came here, and you say I do not provide sources good enough. Ok, that's okay with me, it's your opinion, but if you do not like my contribution, simply be open about it.

I don't like your contribution. It's WoT Forums level shit, complete with bizarre white knighting for a tank.

The M1 isn't gonna let you fuck it, bro, no matter how hard you defend it on the Internet.

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15 minutes ago, Damian said:

Object 187 upper glacis is the same RHA below 100mm thickness... so again what is the point?

 

This is why you shouldn't believe wikipedia about the technical aspects of tank design.  Wikipedia articles about tanks are often written by people that have no idea what they're talking about.  Also, I have heard rumors that they are occasionally vandalized by hooligans.  Does it make any sense to you that a tank designed to replace the T-64, T-72 and T-80, all tanks that had composite hull armor, would itself lack composite hull armor?

Moreover, even if the Object 187 prototypes didn't have the composite modules actually installed (no way to be sure), the clearly had provisions for advanced armor on the hull and turret.  Here's a picture of one of them with hull ERA installed:

iKBRiH4.jpg

and here is a picture of the turret composite armor package:

3yGBNN2.jpg

Also, what makes the Object 187 glacis design so good isn't the specific armor package that was used in it, it was the shape.  Unlike every other modern tank it lacked the weak point around the driver's position.  But you should know this already, you wrote an article on it once.

I'm beginning to get the impression that you simply enjoy arguing.

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Taking the Object 187's glacis as a basis for frontal hull layout, combined with the T-14s and from what we learned about composite armor, how well do you think this would work?

tfOyOoh.png

Black - RHA.
Grey - NERA plates.
Orange - High Hardness shatter plate (ex. DU).
Yellow - Lighter High hardness shatter plate (ex. ceramics).
Dark blue - Backing plate (ex. HHS, HH aluminum alloy.)
Light blue - Absorbing material (ex aluminum).
Green - Liquid cell.

 

Front layout is similar to the Leopard 2, with a thinner LFP, but not massively thinner like on a T-64. A sloped roof plate like on Object 187, with a closely grouped NERA plates and ceramics to shatter and take out LRP and stop top attack munition.  On the the flat part of the roof, the liquid cells are used instead to provide maximum protection against top attack CE.  The bottom of the crew capsule is covered with a absorbing layer against landmines and IEDs. 

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Hypothetically, convincing everyone that your cheap, disposable MBT is super-duper well armored and nigh impenetrable is a great way to get them to spend a bunch of money on anti-armor systems, especially if you've already determined that it would be impossible to completely protect against any such future technology. Make 'em waste the time and effort, even though your armor never justified it.

Just sayin'. Hypothetically.

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On ‎09‎/‎11‎/‎2015 at 8:56 PM, Collimatrix said:

What about it suggests that it's NERA?  If there's some clue I am missing it.

 

The majority of "special" armor does seem to be NERA though.  So many authoritative sources said that special armor was ceramic-based in the 1970s and 1980s, while polymer/steel composite structures have proven to be the most common.  I strongly suspect it was a deliberate misinformation campaign.

I think I finally have an answer to this old post.

Looking at the availble DTIC documents, research and patents; it seems that glass/ceramic armours really were the secret sauce for a long while. You can actually test this by looking at penetration in glass, normalising ME and TE to RHA and then multiplying the two. Even though glass has only 60% of the TE of RHA, it has a whopping 6 times ME. Which means that, overall, it is 3.6 times as efficient as RHA.

This is amazing, given that magic titanium alloy has only 1.8 times the efficiency. Even better; glass is cheap and easilty castable. I can't test harder ceramics directly, but my guess is that they'd be better still. And that's just against long rods - ceramics are even more effective against shaped charges.

 

So far, so good. However; even with this comparative advantage over steel you're still looking at an areal density of something like 2000kg/m^2 to stop a modern APSFS round. To the scientists working on this stuff, then, ERA/NERA must have seemed like a quantum leap in effectiveness. So my guess is that the second they had got the data in all the research on NERA was locked up tight. The glass/ceramic sandwich stuff, which had seemed like the answer a short while ago, was now allowed to dribble into the public domain due to irrelevance. The only information about NERA that made it through to the public was in the form of garbled rumours about arrays of special plates suspended inside the armour package. From there on, simple extrapolation (and a bit of cod logic) gets you the honeycomb laminates and super-ceramics that we heard about in the 90's.

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3 hours ago, Sturgeon said:

Hypothetically, convincing everyone that your cheap, disposable MBT is super-duper well armored and nigh impenetrable is a great way to get them to spend a bunch of money on anti-armor systems, especially if you've already determined that it would be impossible to completely protect against any such future technology. Make 'em waste the time and effort, even though your armor never justified it.

Just sayin'. Hypothetically.

The idea that no modern tank can achieve protection across more than a limited frontal arc jives well with the fact that modern tanks do well when crewed by competent soldiers and die in droves when crewed by Saudis or Iraqis. If your magic armour only works from the front (and then only in certain spots) you need to be good at your job to stop people from flanking you.

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For a side-note triplepoast: the limitations of the longrods calculator still allows you to test a few interesting things.

For instance; tooth enamel has about 2.5 times the effectiveness of RHA against APDSFS (3.8ME; 0.7TE). Which means that Godzilla could actually do pretty well against tanks if he had thick enough scales and sub-dermal plates (about 40cm thick each) of the correct type.

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3 hours ago, Toxn said:

I think I finally have an answer to this old post.

Looking at the availble DTIC documents, research and patents; it seems that glass/ceramic armours really were the secret sauce for a long while. You can actually test this by looking at penetration in glass, normalising ME and TE to RHA and then multiplying the two. Even though glass has only 60% of the TE of RHA, it has a whopping 6 times ME. Which means that, overall, it is 3.6 times as efficient as RHA.

This is amazing, given that magic titanium alloy has only 1.8 times the efficiency. Even better; glass is cheap and easilty castable. I can't test harder ceramics directly, but my guess is that they'd be better still. And that's just against long rods - ceramics are even more effective against shaped charges.

 

So far, so good. However; even with this comparative advantage over steel you're still looking at an areal density of something like 2000kg/m^2 to stop a modern APSFS round. To the scientists working on this stuff, then, ERA/NERA must have seemed like a quantum leap in effectiveness. So my guess is that the second they had got the data in all the research on NERA was locked up tight. The glass/ceramic sandwich stuff, which had seemed like the answer a short while ago, was now allowed to dribble into the public domain due to irrelevance. The only information about NERA that made it through to the public was in the form of garbled rumours about arrays of special plates suspended inside the armour package. From there on, simple extrapolation (and a bit of cod logic) gets you the honeycomb laminates and super-ceramics that we heard about in the 90's.

Toxn, I think you are making a wrong conclusion. While glass can have a very high thickness and mass efficiency in laboratory testing, it won't have such an efficiency in actual applications. Glass is one of the weird materials (much like ceramics vs KE ammunition) that losses efficiency when sloped. You can see how the thickness efficiency of different steel-glass-steel sandwiches is influenced by the slope in "Glass Armour and Shaped Charge Jets" by Dr. Manfred Held. The most effective glass and steel sandwich plate provided a thickness efficiency of about 3 when not sloped, but sloping the armor at 60° resulted in a decrease of TE to only ~1.1. This value was however measured against "jet guns" (extremely unoptimized shaped charge warheads (e.g. something comparable to WW2 quality) at only 10 inches (254 mm) standoff distance.  

TU6sRon.png

Based on assuming that the tested glass has the average density of standard civilian glass, this would result in a mass efficiency of up to 5.47 when not sloped, but only 2.0 when sloped at 60°.

p8BJ4P2.png

The biggest issue with such experiments and laboratory testing is however that the TE and ME are always exaggerated as a result of the test setup. An nice example is the different glass armor tested by Dr. Held against a 115 mm Milan K (Milan-2) warhead with a standoff distance of 345 mm. The reference plate was spaced 16 calibres (1840 mm !) away from the the glass armor module, in order to allow making high-speed radigraphic photos of the distrubed shaped charge jet. The huge distance between armor module and reference plate affects the TE and ME drastically, as the disturbed shaped charge jet losses much more penetration power than in a regular armor layout. 

aiE7fJq.png

This can be somewhat seen in another test by Dr. Held, where "conventional" NERA consisting of a 2 mm steel plate, a 20 mm Dyneema plate, and a 4 mm steel plate were used as NERA sandwich against a Milan K warhead. The warhead was placed 350 mm in front of the armor, which was sloped at 60°. The distance to the reference target was 1700 mm. This armor reduced the penetration of the 115 mm shaped charge by 400 mm, i.e. the thickness efficiency (not accounting the empty space) would be 7.7! Given that  the Dyneema has an extremely low areal density (21 kg/m²) the ME would be 23.4! This is an incredible level of protection per weight, but cannot be achieved on actual tanks, due to the limitations to the armor volume and the need of layering the armor.

Glass armor and ceramics have a very different defeat mechanism. Glass has a bulging effect (a result from glass locally changing it's density during penetration), thus can be used as an interlayer material for NERA. Ceramic armor on the other hand does not have such a behaviour, Chinese tests of aluminium oxide against shaped charges show a TE of ~1.0-1.1 and a ME of ~2.2-2.3.

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Thanks for the detailed post!

However; I'm not assuming anything about slope or the real limitations of ceramics. I'm simply laying out what I think is a plausible story for why glass or ceramic sandwiches got into the public domain while NERA didn't.

 

My argument is that researchers really were working on glass and/or ceramic arrays (the DTIC documents confirm this) and were very excited about them at some point. But, as you just pointed out, NERA arrays are much better than sandwich arrays (4X efficiency in tests compared to 20X efficiency). So my guess is that, having discovered NERA, the researchers were then very hush-hush about disclosing it. The older sandwich array designs, however, got discussed and slowly leaked into the public domain.

 

Now, you're a reporter and you know something about glass sandwich arrays. But you also know that the work going on that you've heard about was a decade ago. So, having heard almost nothing about new tanks with fantastically effective new armour arrays, what is your assumption?

My guess is that you put together what little you can find out (something about special plates inside the armour package) and add it to what you already know (the layered composite arrays). Add in a few hints about fantastic materials (super-ceramics, advanced polymers, depleted uranium) and you end up with the story about composite armour (honeycomb arrays, supermaterials, plates 'turning' inside a polymer matrix) that we all got told up until a few years ago.

 

TL;DR - Secrecy and the unexpected nature of the advance in technology is what lead to all the stories about fantastic sci-fi materials used in modern tank armour. All along, however, the real secret sauce was in attacking the problem from another angle.

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2 minutes ago, SH_MM said:

That sounds pretty reasonable. I wouldn't be surprised if the same "glass/ceramics are super" myth has repeated itself with other technologies (I am looking at you, heavy metal alloys in armor!).

Reporters again. The idea of tempering goes straight over, but the fact that there's 0.01% tungsten in there sticks.

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21 hours ago, Collimatrix said:

Also, you can see from that image that the hull protection on the Abrams, even accounting for the fuel cells, is not spectacular.

This is a flaw shared by many Western MBTs, sadly.

 

edit:  and most Soviet ones, come to think of it.

Hull armor was never more, or even, as important as turret armor, because the turret is exposed far more frequently, thus more susceptible to being hit. Explaining why turrets have traditionally better armor than tanks' hulls.

The exception would be the T-14, which chooses to rely solely on an APS for its turret's protection. A bad call I believe. While the turret is no longer manned, it is definitely just as much exposed to hostile fire. 

20 hours ago, Collimatrix said:

Not on the upper glacis it isn't.

We're getting off topic, but basically all MBTs have a weak spot around the driver's position.  The Challenger 2 is the worst offender, 

I wouldn't say "all". At least the Leclerc and Merkava, who share a rather similar protection scheme, don't have that weak spot. 

20 hours ago, Damian said:

That's your problem, first I never seen a hit in the M1's upper glacis, because it's so small target, second thing is, there is still big chance of a bounce due to angle. You don't like it, well, find a better design... oh wait, there isn't a better 3rd generation designs. So yeah, this is a pointless discussion.

Pretty sure that somewhere in the AW forums, in one of the threads that I cannot recall its name, there were pictures of an M1A1/2 (don't remember which) pierced in its UFP by an ATGM which IIRC was a Konkurs. 

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There's plenty of discussion of glass in armour arrays in hunnicut - IIRC it was considered for M60 or T95

On 15/02/2017 at 3:32 PM, Renegade334 said:

I surmise then that filling spaced armor cavities with fluids (fuel or otherwise) is not worth the trouble, compared with just leaving air between the plates, since it'd cause a rather consequent increase in weight?

I remember (from AW's forum, some time ago) some Soviet tanks having those turret cavities filled with some sand/concrete-like matter. Does it merely absorb shockwaves or slow down KE projectiles, or does it have some sort of abrasive effect on penetrators (whittling it down or simply deforming it) and such?

Density of diesel is about 1/10th that of steel, so if it's 7 times less effective on a thickness basis then you're still ahead

2 hours ago, Mighty_Zuk said:

The exception would be the T-14, which chooses to rely solely on an APS for its turret's protection. A bad call I believe. While the turret is no longer manned, it is definitely just as much exposed to hostile fire. 

It does have a much lower frontal area than any MBT with a manned turret, so hits to the turret will be less likely

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I don't think that's really an argument. Soviet tanks were designed with the principle of being smaller to minimize chances of being hit (though largely also because of bad infrastructure), and look where that got them - it cost the users a great deal of lives, cost them capabilities, and eventually they abandoned it. All that anyone ever had to do to counter this design feature was make a digital FCS (not those funky Chally stuff) that is reliable enough. Surely even a narrow turret isn't much of a problem nowadays. 

I know there's a whole debate surrounding this, about whether the T-14 (or any future MBT) is going to sacrifice mobility to get better protection, or sacrifice protection for better mobility (current state). Doctrine-heavy.

Russia could have gotten that sweet spot in between by at least making a turret that is ready to accept various configurations, including a modular armor on short notice, but it didn't. They went instead with having a wholly modular turret, which means they can still change it (and it's a very good future-proofing decision) but they will not be ready on short notice. 

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Digging back into the earlier posts, the tests seem to show that a single rubber NERA array plate expands to about 5X its original thickness when hit by a shaped charge.

 

My question here is what effect does stacking the plates closer together have on effectiveness? Presumaby sticking the plates too close together will limit their effectiveness, but at the same time you want to stack them quite closely to maximise the amount of material the penetrator has to go through.

 

Follow-up question: is there a penetration calculator for shaped charges comparable to the longrods calculator?

 

Yet another question: does anyone have TE values of unusual materials against APFSDS and/or shaped charges? I just ran some speculative numbers on reinforced concrete, and the results against long rods should actually be pretty good (0.6 TE) according to calculations. Which makes me think that the calculations are off somehow.

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Hi everyone. This is my first post! I'm the guy behind the Tankograd blog https://thesovietarmourblog.blogspot.com/ Mike E, which I think is a familiar name to some of you, used to help me out there.

I've done some research into NERA armour in order to better understand the armour of the T-72B, but I definitely don't pretend to know all about it. I've posted some stuff on NERA in my blog's T-72 article, but I'll repeat the most relevant bits here. According to Rolf Hilmes, adding a heavy armour plate in front of the NERA plate boosted the overall effectiveness against KE projectiles. No idea how true this is, but the guy that said it is a world expert on the topic, so hey. As far as I can tell, the heavy plate presumably contributes by fracturing or chipping part of the projectile before it enters the NERA plate, where it is further damaged, but to be honest, I don't know the exact mechanism.

Comparisons between independent research involving NERA plates of the same configuration but with different bulging plate hardness has shown that the hardness of the bulging plates directly affects the ability of the NERA armour to disrupt shaped charge jets. So using titanium or aluminium is actually very counterproductive. It is better to use high hardness steel sheets. We must not forget that even though titanium and aluminium may sometimes have better ME than steel, you need quite a large thickness to achieve the same relative armour thickness. When we are talking about bulging plates, thick = bad. Thick plates are very stiff, and that makes it difficult for it to be bulged by the interlayer. But this is not a problem if the objective is to feed as much material as possible into the path of the projectile, right? The thing is...

 

4 hours ago, Toxn said:

My question here is what effect does stacking the plates closer together have on effectiveness? Presumaby sticking the plates too close together will limit their effectiveness, but at the same time you want to stack them quite closely to maximise the amount of material the penetrator has to go through.

 

... the point of NERA probably isn't to feed material for the projectile to penetrate. It is to impart lateral forces. With that in mind, I think that it is better to have more space. This enables you to impart forces on a bigger area of the projectile.

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41 minutes ago, Iron Drapes said:

I've done some research into NERA armour in order to better understand the armour of the T-72B, but I definitely don't pretend to know all about it. I've posted some stuff on NERA in my blog's T-72 article, but I'll repeat the most relevant bits here. According to Rolf Hilmes, adding a heavy armour plate in front of the NERA plate boosted the overall effectiveness against KE projectiles. No idea how true this is, but the guy that said it is a world expert on the topic, so hey.

Source? Because he says pretty much directly the opposite about the T-72B's (T-72M1M's) armor in his book "Kampfpanzer heute und morgen: Konzepte - Systeme - Technologien", page 382.

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52 minutes ago, Iron Drapes said:

Hi everyone. This is my first post! I'm the guy behind the Tankograd blog https://thesovietarmourblog.blogspot.com/ Mike E, which I think is a familiar name to some of you, used to help me out there.

I've done some research into NERA armour in order to better understand the armour of the T-72B, but I definitely don't pretend to know all about it. I've posted some stuff on NERA in my blog's T-72 article, but I'll repeat the most relevant bits here. According to Rolf Hilmes, adding a heavy armour plate in front of the NERA plate boosted the overall effectiveness against KE projectiles. No idea how true this is, but the guy that said it is a world expert on the topic, so hey. As far as I can tell, the heavy plate presumably contributes by fracturing or chipping part of the projectile before it enters the NERA plate, where it is further damaged, but to be honest, I don't know the exact mechanism.

Comparisons between independent research involving NERA plates of the same configuration but with different bulging plate hardness has shown that the hardness of the bulging plates directly affects the ability of the NERA armour to disrupt shaped charge jets. So using titanium or aluminium is actually very counterproductive. It is better to use high hardness steel sheets. We must not forget that even though titanium and aluminium may sometimes have better ME than steel, you need quite a large thickness to achieve the same relative armour thickness. When we are talking about bulging plates, thick = bad. Thick plates are very stiff, and that makes it difficult for it to be bulged by the interlayer. But this is not a problem if the objective is to feed as much material as possible into the path of the projectile, right? The thing is...

 

 

... the point of NERA probably isn't to feed material for the projectile to penetrate. It is to impart lateral forces. With that in mind, I think that it is better to have more space. This enables you to impart forces on a bigger area of the projectile.

Welcome!

 

Look at some of my previous posts - I mentioned the application of lateral force.

What greatly puzzles me is how the actual NERA arrays we have pictures of seem to contradict what little coherent theory we have about how they work. If you go over the pictures posted earlier, you find arrays with very small gaps (or no gap), arrays with thicker front plates than back plates and arrays were a lot of the NERA plates are orthogonal to the axis of the penetrator rather than at an oblique angle. I'd love to know why.

 

I agree with you that NERA plates should be further apart (again, see my earlier posts), as the brute physical reality is that the only way to seriously lower the penetration of a long rod or shaped charge jet is to somehow disrupt it or break it up.

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Second hand source, unfortunately: http://below-the-turret-ring.blogspot.my/2017/01/early-m1-abrams-composite-armor.html

"A common design principle according to Dipl.-Ing. Rolf Hilmes, who formerly worked at the German BWB, and according to a presentation from the British Defence Science Technology Laboratory (DSTL), is to incorporate a further heavy layer in front of the armor array, which servers to disrupt (shatter/break) the projectile, before the fragments enter the NERA array."

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Slight erratum: I realised that my calculation for ME was wrong, and replaced it. The results make MExTE comparisons much less spectacular, as most things only get a bit over RHA overall.

 

I also ended up with enough stuff to stick into excel and made a solver for arrays to stop long rods. So far, the results seem to show that magic quatz would be the way to go, but the picture becomes much more complicated once you adjust it to a realistic sandwich array.

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