anti KE reactive armor

[Mighty_Zuk]

Rafael has showcased its Armor Shield KE, or ASPRO-KE.
An Israeli defense website published an interview with a Rafael official, so I'll post the main points:

1. The only system said to fully deal with KEPs is Iron Fist, an active system. But Rafael takes a different approach, saying even a deflected penetrator would inflict damage. They prefer using the APS for anything other than KE, and absorb the KEP with reactive armor.

2. Rafael's main competitor is the US Army which develops for itself, but considers itself a global leader in this field.

3. The weight is still prohibitive and suitable for MBTs, at up to 750kg/m2 for turret front, 400kg/m2 for turret side, and 375kg/m2 for hull front.

 

4. The effect versus APFSDS is tremendous - up to 54% in simulations, and roughly 50% reduction in penetration power in live tests.

5. Defeats existing 125mm APFSDS and said to work against KEPs of any caliber.

6. The ERA shatters the KEP into fragments and prevents penetration of the outer layer of the armor.

7. The KEP activates the ERA with its heat and friction, triggering it when a real threat is identified, preventing false activation.

8. Hundreds of tests were made, and the blast does not endanger nearby troops.

9. The ERA module will work on multiple threats so long as two different shells are not hitting the exact same point, as in "shoot through a hole", which is true for any type of armor ever. This is indeed a very significant development.

10. The IDF has yet to purchase this armor, and Rafael is marketing it abroad for now.
 

 

 

 

I cannot exaggerate the importance of this. In the past, an entire module that was shot through, was gone. Here, you have an ERA module with the weight of conventional ERA and its single hit effectiveness, with the multi-shot survivability of completely passive armor.
This is the best of both worlds, so to speak, and a lightweight, survivable ERA against KE will give western tanks a protection capability against the most advanced Russian and Chinese APFSDS.

[methos]

You are exaggerating this quite a bit. Obviously Rafael will pretend that its new ERA is some sort of breakthrough in design and technology, but in reality it seems to be nothing really special. It is just not casette-based and uses insensitve exposives. In reality multi-hit capability will still be far lower than that of a fully inert reactive armor and the fact that it is not casette based  (or rather it has an exterior cover plate, the figure in the slide clearly shows an ERA casette) means that repairing/replacing the ERA modules will be more cumbersome. This is a choice made to reduce fragmentation.

A reduction of 50% in penetration power might sound massive, but in reality that is a 250-300 mm reduction in penetration power for a weight of 700 to 750 kg (equvialent to a 95 mm steel plate). That's a mass efificiency of 3.15 at best - good, but certainly not unheard of, specifically for ERA.

17 hours ago, Mighty_Zuk said:

9. The ERA module will work on multiple threats so long as two differ ent shells are not hitting the exact same point, as in "shoot through a hole", which is true for any type of armor ever. This is indeed a very significant development.

Not according to Rafael's presentation at IAV 2021.

 

[Mighty_Zuk]

1 hour ago, methos said:

means that repairing/replacing the ERA modules will be more cumbersome. This is a choice made to reduce fragmentation.

The entire module is meant to be replaced, not a single casette. 

Damaged modules can be repaired in a depot so the actual difference to maintenance and logistics isn't great.

1 hour ago, methos said:

A reduction of 50% in penetration power might sound massive, but in reality that is a 250-300 mm reduction in penetration power for a weight of 700 to 750 kg (equvialent to a 95 mm steel plate). That's a mass efificiency of 3.15 at best - good, but certainly not unheard of, specifically for ERA.

Those are not representative numbers. One can skew them in a way that gives the module a mass efficiency of 10. 

How? A module for the hull front weighs 350kg, including mounting and all. Why the difference in weight? Because the turret front module weighs twice as much as a hull front module.

A nearly meter long 125mm penetrator might pierce anything up to 900mm. Half that would be 450mm. 

450mm reduction for the equivalent of a 45mm plate is 10:1 weight efficiency. 

So if you are trying to make a case here, improve it.

1 hour ago, methos said:

Not according to Rafael's presentation at IAV 2021.

I haven't seen the presentation. But I have an interview a Rafael official gave about it.

Seeing that you have not actually specified anything about the presentation at IAV, you haven't seen it either.

[methos]

4 hours ago, Mighty_Zuk said:

Damaged modules can be repaired in a depot so the actual difference to maintenance and logistics isn't great.

The differnce "isn't great"? You just need a crane to lift the armor modules rather than letting the soldiers install the ERA casettes by hand!

4 hours ago, Mighty_Zuk said:

Those are not representative numbers. One can skew them in a way that gives the module a mass efficiency of 10. 

No, these are pretty representative numbers, because the ERA's performance is not independent from the type of the round and the thickness of the ERA. The figures I provided are based on the IAV 2021 talk done by Rafael, i.e. Dr. David Gershon's presentation "Vehicle Survivability & Defeating Long Rod Penetrators" where the new Armouur Shield KE ERA was first showcased.

The simulation showing a 56% decrease in penetration was done with a computer-simulated turret ERA module. The actual test firings showcased by Dr. Geshron (as slow-motion video footage) were a reduction in penetration performance of 48-50% was achieved were also conducted against a simulated turret front with the heavy ERA solution. The lighter hull ERA won't reach the same level of performance.

Btw. this is how the turret armor module looked after two hits with APFSDS rounds:

Unfortunately the enconding of the IAV livestream is not of perfect, so please apologize for the blurry image. This ERA module contains four casettes (internally mounted) with Rafael paying attention to shoot different ones.

The exact weight of this test configuration was 725 kg/m² according to the slides.

I also didn't choose the penetration figures randomly; while Dr. Gershon was no willing to disclose the exact type of APFSDS used, the stated muzzle velocity of 1,740 m/s suggests it was the DM43/KEW-A1/OFL F1 APFSDS round, which will only penetrate ca. 550-600 mm of unsloped steel armor (as used for measuring residual penetration during the test). This also matches the penetrators visible in the slow-motion videos:

5 hours ago, Mighty_Zuk said:

A nearly meter long 125mm penetrator might pierce anything up to 900mm. Half that would be 450mm. 

They didn't use a nearly one meter long penetrator for tests. The penetration reduction would be lower for a longer penetrator; based on the simulation shown during the IAV 2021 livestream, the Armor Shield KE module bends the frontal section of the longrod penetrator and applies yaw (ca. 2.7° in the simulation) to the whole rod. Weighing as much as 95 mm of steel armor, it also will provide a decent amount of "passive protection".

The impact of the first mechanism (bending) and of the "passive protection" will be lower the longer/the more powerful a penetrator gets, as more of it will remain unaffected by it.

5 hours ago, Mighty_Zuk said:

Seeing that you have not actually specified anything about the presentation at IAV, you haven't seen it either.

I have watched it and I have a recording of it.

[Mighty_Zuk]

Then if you have it recorded, please show it. Posting these images instantly made your case stronger.

[Interlinked]

I second what methos said. This is pretty unremarkable.

[Mighty_Zuk]

Except Methos has yet to provide a link to the presentation so there is still doubt. I'm willing to correct myself if needed, but the evidence is yet to be presented.

[methos]

I have not gotten permission to post the video and due to local laws I could be penalized for doing so (copyright infringement and recording).

 

However someone else (presuambly from a country with relaxed copyright laws...) has uploaded the video and most other IAV talks on Vimeo.

[P Lakowski]

I  could not up load anything  from that Vimeo link.

[P Lakowski]

duplicate please delete

 

Edited April 14, 2022 by P Lakowski
please delete

[KV7]

Does anyone have any material on anti KE NERA ? I think in the 1970's there were experiments with steel rods or perforated plates sprung or in elastomer in the centre of some cavity.

[P Lakowski]

That sounds like the armor added to the LEOPARD 1A1A1 in the late 1970s , and the follow on armor added to the MARDER 1A1....RAFAEL published some papers on STEEL- NERA STEEL  targets struck by long rod penetrators , but there were not any vs perforated plate.

Edited April 17, 2022 by P Lakowski

[methos]

On 4/14/2022 at 5:47 PM, P Lakowski said:

I  could not up load anything  from that Vimeo link.

It seems that Vimeo changed its pricing plans and terms & conditions, so the user deleted that video. I've made plenty of screenshots that I can share if desired.

9 hours ago, KV7 said:

Does anyone have any material on anti KE NERA ? I think in the 1970's there were experiments with steel rods or perforated plates sprung or in elastomer in the centre of some cavity.

From what I know, any modern anti-KE NERA will look just like normal NERA, but with thicker metal plates & also thicker interlayer material. This is at least suggested by research papers from Germany, the Netherlands and Switzerland.

There were also designs tested in West-Germany, which had an "indented" coverplate - i.e. a perforated plate, which didn't completely reach through. E.g. one example consisted of a 25 mm steel plate with 10 mm deep indentations, a 6 mm rubber layer and 1 mm backplate.

Apparently this design did not work better than normal NERA - or provided only a minimal gain in protection that was not worth the effort - so that the Leopard 2(AV) used conventional NERA consisting of a 30 mm front plate and a 4 mm back plate., somewhat similar to the T-72B's turret NERA consisting of 21 mm front and  3 mm backplates.

Edited April 17, 2022 by methos

[Mighty_Zuk]

23 minutes ago, methos said:

It seems that Vimeo changed its pricing plans and terms & conditions, so the user deleted that video. I've made plenty of screenshots that I can share if desired.

If you have any beyond what's been posted here, please share.

[Mighty_Zuk]

8 hours ago, P Lakowski said:

RAFAEL published some papers on STEEL- NERA STEEL  targets struck by long rod penetrators , but there were not any vs perforated plate.

Can you share this material please?

[Sardaukar]

Maybe this?

https://patents.google.com/patent/US7360479B2/en

[P Lakowski]

4 hours ago, methos said:

It seems that Vimeo changed its pricing plans and terms & conditions, so the user deleted that video. I've made plenty of screenshots that I can share if desired.

From what I know, any modern anti-KE NERA will look just like normal NERA, but with thicker metal plates & also thicker interlayer material. This is at least suggested by research papers from Germany, the Netherlands and Switzerland.

There were also designs tested in West-Germany, which had an "indented" coverplate - i.e. a perforated plate, which didn't completely reach through. E.g. one example consisted of a 25 mm steel plate with 10 mm deep indentations, a 6 mm rubber layer and 1 mm backplate.

Apparently this design did not work better than normal NERA - or provided only a minimal gain in protection that was not worth the effort - so that the Leopard 2(AV) used conventional NERA consisting of a 30 mm front plate and a 4 mm back plate., somewhat similar to the T-72B's turret NERA consisting of 21 mm front and  3 mm backplates.

yes it was declared from the first model that the holes in the plate had to be fine tuned to a targeted rod diameter. So in the LEOPARD 1 A1A1 Side turret plates the holes were visibly smaller than the holes in the front turret plates. I will keep digging . isn't   TK CIAR [sp] around he used to have most of the IJIE material uploaded to the net?

 

 

BTW EXCELLENT THREAD AND LINKS, I'VE BEEN AWAY TOO LONG.

Edited April 17, 2022 by P Lakowski

[Mighty_Zuk]

4 hours ago, Sardaukar said:

Maybe this?

https://patents.google.com/patent/US7360479B2/en

That one is unrelated to Lakowski's comment.

[methos]

11 hours ago, Mighty_Zuk said:

Can you share this material please?

There isn't much more on the Armor Shield KE (though a lot more was said than shown), but here are the slides. Worth noting that the obstrusive QR code was from the Vimdeo video uploader, it leads to some kind of Firefox add-on that can be used to record live streams... it wasn't there during the actual video conference.

Agenda

https://imgur.com/ISTFM4w

1. Passive Armor

2. Active Protection

3. Reactive Armor

4. (Defeating) Long Rod Penetrators

Just some re-hashing of Armor Shield P marketing material. I don't remember anything new being mentioned there.

SPINEL transparent armor, at the time a new/revent product of Rafael. Basically just transparent ceramic armor, various similar products are already available on the market.

Only slide of the second chapter. Very briefly mentioned a few things about APS design.

Overview on Rafael's reactive armor product, IIRC nothing specific was mentioned. The list on the left is covered by different types of ERA, not one. Interestingly he didn't mention any anti-tandem developments.

The MTAP ERA, fielded as part of the US Army's Urban Survivability Kit III on the M2 Bradley (only the lowermost row on the side skirts). Specifically designed to also defeat EFPs.

First really interesting product, reactive roof armor. Again just a bare overview of the system's concept.

Proposal to field optimized ERA solutions designed to be used together with APS. Large weight-savings possible, but it is not exactly stated how these can be achieved on the M2 Bradley (as the Bradley's ERA doesn't stop ATGM or HEAT tank shells). IMO the Bradley is just used as placeholder graphic and the actual weight reductions can only be achieved on tanks.

 

[methos]

Fourth section of the presentation, starts with a focus on APS.

Conclusion by Rafael: APS currently cannot reliably defeat longrod penetrators (in case of interceptor-based systems) or does not offer enough performance (in case of wall-mounted systems)

Design of the reactive element of Armor Shield KE. We already discussed relevant details earlier.

Simulations of Armor Shield KE interacting with a longrod penetrator. The penetrator stays intact and is bend & slightly yawed.

Set-up for the test firings. Two projectiles (IMO two shots with KEW-A1/DM43)

First test shot. Performance is a bit worse than predicted.

Second test shot, performance again is a bit less than predicted, so roughly what Russia claims for Relikt (but without any anti-tandem capabilities).

Last slide, basically Dr. Gershon saying "as we see, Rafael provides protection solutions against everything" and that a combination of different systems is required for optimum protection. After that there was five minutes of Q&A, but I cannot remember anything interesting.

 

[methos]

7 hours ago, P Lakowski said:

yes it was declared from the first model that the holes in the plate had to be fine tuned to a targeted rod diameter. So in the LEOPARD 1 A1A1 Side turret plates the holes were visibly smaller than the holes in the front turret plates

The Leopard 1A1A1's add-on armor was designed against 100 mm APHE at the front and 20 mm APCR at the sides, which explains the different size of the holes and the different plate thickness.

[P Lakowski]

The original specification for LEO-1A1A1 , Was to raise A1 armor  to the A2 levels, ERGO open to interpretation .The KE figures could be 100mm APBC @ 1600m  ,

which are 85mm @ 54o  and 157mm @ 0o. ....   157mm to 161mm ; roughly 16cm     or      more accurately 6".  i'll crunch some shaped charge numbers.....

 

 

 

 

 

Edited April 18, 2022 by P Lakowski

[methos]

Paul, your old estimates are outdated. In the recent years a lot of declassified documents containing relevant informations have been dug-up - a lot of excerps have been posted on TankNet.

4 hours ago, P Lakowski said:

The original specification for LEO-1A1A1 , Was to raise A1 armor  to the A2 levels, ERGO open to interpretation .The KE figures could be 100mm APBC @ 1600m  ,

With the Leopard 1A1A1 armor upgrade, the protection is on par with the Leopard 1A3 & 1A4 models which featured the new welded turret with built-in spaced armor. The Leopard 1A2's cast turret was thickened compared to the 1A1 model, but only at the sides. The side armor of the original Leopard 1A1 only managed to meet the required level of protection (stopping the 20 mm DM43 APCR round) when taking the turret's shape into account; when hit from an elevated position (or when the tank was on very uneven ground) so that the slope of the turret side armor was nullified, it still could be penetrated by the DM43 APCR round. The Leopard 1A2's turret was protected against it even in such a case.

Turret protection levels of Leopard 1A1, Leopard 1A2, Leopard 1A3, first generation Leopard 2 prototype (pre-1973) and Leopard 1A1A1.

The 1A1 and 1A2 turrets could be defeated by 100 mm APHE at ranges shorter than 2,500 m and by 57 mm APCR ar 2,000 m distance. The Leopard 1A3 and 1A1A1 reduced the range at which 100 mm APHE could defeat the frontal armor to 1,000 m (and increased the frontal arc from 0° to 10°) while providing immunity against 57 mm APCR ammunition. With that the frontal turret provided equal protection to the M60A1's.

The 1A3 turret was also successfully tested against 90 mm HVAP (APCR) which on paper has a higher penetration than 100 mm APHE.

4 hours ago, P Lakowski said:

i'll crunch some shaped charge numbers.....

There was no requirement for the Leopard 1 turrets to stop shaped sharge warheads (except for the never adopted 1A6 model). As far as I know, there weren't any tests with shaped charge warheads against the 1A2 and 1A1A1 turrets, because it was assumed that 73/76 mm HEAT-FS was already more than enough to defeat them.

Edited April 18, 2022 by methos

[methos]

On 3/27/2021 at 4:36 PM, Mighty_Zuk said:

How? A module for the hull front weighs 350kg, including mounting and all. Why the difference in weight? Because the turret front module weighs twice as much as a hull front module.

Btw. the answer for this question is most likely the (assumed) slope. The frontal hull is likely sloped, so when the ERA applies yaw to the penetrator, the path of travel will increase even further, as it will travel through the sloped plate. Meanwhile the turret front is assumed to be flat, hence a heavier module will be required to achieve the same level of protection.

[P Lakowski]

 

What is the reference penetration figures at range for the .....

100mm APHE round?

90mm APCR shot?

20mm HVAP SHOT  more specifically dm43 @ 100m @ 20o

What is the ballistic criteria in these test figures ?