Dangers of ERA

[2-pies]

I have been reading several topics recently concerning ERA.  It seems to me that the concept of explosive defensive munitions is dangerous to both the exposed vehicle crew and dismounted troops nearby.

For example, I was watching video of T-72s in action in an urban environment - the camera was fixed to the turret top behind the ERA boxes, and it occured to me that if the TC had his head out the cupola and the ERA detonated this would not have a happy outcome.  It may not be shrapnel wounds, but close proximity detonations can cause burst ear-drums and detached retina for example.

Another example is the talk of fitting IFV/APCs with ERA.  I see two problems here - one is ERA exploding in close proximity to friendly dismounted troops.  The second problem is the relatively light construction of these vehicles and subsequent shock/personal damage.

I have three questions:
1. Is there a Master Arm switch to de-activate the ERA ?
2. Is it tactical practice to operate ERA equipped vehicles always buttoned-up  i.e. all hatches closed ?
3. Are the ERA effects on personal modelled in Steel Beasts ?

Tactically, I see the side using ERA would be tactically disadvantaged from the start by being forced to operate with restricted awareness.

[Damian90]

1. No, there is no master arm switch, ERA as name suggests is reactive, it's a explosive material in between steel plates (in it's most conventional form) which detonates when ERA module is hit by large enough projectile which can apply enough pressure on explosive material to make it detonate.

 

2. Not really and it depends on ERA type and it's placement, I seen US M1A1/M1A2 tanks equipped with ERA that had it's turret hatches opened. On the other hand Russians preffer to operate with hatches closed.

 

Also you need to understand that for infantry around vehicle it does not matter of this vehicle have ERA or not. If it's struck by RPG, ATGM or HEAT, there will be enough fragments flying around that it will kill any infantry nearby. Besides ERA in reality does not use lots of explosives, sometimes significantly less than projectiles against it needs to protect. You see explosive in ERA is not there to provide protection, it's there to provide violent and quick reaction to move steel plates (or other protection solutions) inside modules to disturb shaped charge jet or bend/break long rod penetrator.

 

As for lightweight vehicles, special ERA types are designed, which besides smaller amounts of explosives, use various types of other materials to provide sort of isolation for vehicle hull from the shock caused by explosive material detonation.

 

And in the end there are various types of different ERA types with various design features.

 

For tanks and similiar heavier vehicles you have ERA like ARAT-1, ARAT-2, 4S20 Kontakt-1, 4S22 Kontakt-5, 4S23 Relikt, Malachit, Knife, Duplet, ERAWA-1, ERAWA-2, BRENUS, ROMOR-A, Blazer, etc.

 

For lighter vehicles you have BRAT-1, BRAT-2, SRAT-1, SRAT-2, 4S24, Knife-L, Rakietka, CERAWA-1, CLARA etc.

 

These types of ERA have various properties, offers various protection levels, and so on.

[Ssnake]

17 minutes ago, 2-pies said:

For example, I was watching video of T-72s in action in an urban environment - the camera was fixed to the turret top behind the ERA boxes, and it occured to me that if the TC had his head out the cupola and the ERA detonated this would not have a happy outcome.  It may not be shrapnel wounds, but close proximity detonations can cause burst ear-drums and detached retina for example.

 

Well, the question is whether the close proximity impact of an RPG WITHOUT the involvement of ERA would be so much healthier to an unbuttoned crew member. If the answer is that the damage would be equal or worse, just that the RPG/missile warhead perforates the armor in one case and leaves the vehicle intact in the other, case closed.

 

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Another example is the talk of fitting IFV/APCs with ERA.  I see two problems here - one is ERA exploding in close proximity to friendly dismounted troops.  The second problem is the relatively light construction of these vehicles and subsequent shock/personal damage.

 

Again, would the nearby infantry be better off standing next to a non-ERA protected vehicle while an RPG/missile warhead detonates, or is the risk to life and limb comparable. If the latter, case closed.

 

 

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I have three questions:
1. Is there a Master Arm switch to de-activate the ERA ?
2. Is it tactical practice to operate ERA equipped vehicles always buttoned-up  i.e. all hatches closed ?
3. Are the ERA effects on personal modelled in Steel Beasts ?

Tactically, I see the side using ERA would be tactically disadvantaged from the start by being forced to operate with restricted awareness.

 

1. No.
2. You button up under just the same conditions. Buttoning up makes you "feel" safer, but does not necessarily make you safer due to the loss of situational awareness.
3. No.

[12Alfa]

I believe the way to go is in the form of cages, there are a few types you can Google. They are people friendly, easily to mount, and a lot more inexpensive. And they work without placing explosives on your AFV and effective.

 

That said, I been in such a AFV and survived a RPG attack so I'm a big fan, if it were Any type of ERA the civies near us would not be walking on this planet right now.

Of course a expert may chine in as usual , just wait for it

Edited September 27, 2016 by 12Alfa

[Damian90]

Of course cages have advantages, they are cheaper, and do not use explosives.

 

However cages are only effective against relatively simple, single warhead RPG granades, and even then efficency is only 50% at best, which means sometimes cage will work, sometimes not.

 

Cages however are completely ineffective against tandem warheads, ATGM's or HEAT rounds fired from tank guns.

 

So it's something for something.

 

And the reason why cages are ineffective against some threats it's because how they work.

 

Their purpose is to damage the warhead of RPG and thus break connection from the fuze to the warhead thus preventing detonation, or damaging the warhead in such way that shaped charge jet won't form properly.

 

The problem starts with HEAT rounds, they have much harder, solid shell, thus cage won't work well against them, with ATGM's the problem is that main charge is mostly placed closer to the rear of the missile body, thus it won't reach the bars of the cage, before it's detonate, while tandem RPG's will do the same as ATGM's or even if main charge will be crushed, there is still smaller precursor charge capable to pierce through armor of lightweight vehicle.

 

So there is no perfect solution, which is unfortunate, but that's reality.

[12Alfa]

Source (from this reality Plz) ?

[Damian90]

http://www.globalsecurity.org/military/intro/armor-slat.htm

 

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Slat armor's efficiency is lower than that of dynamic protection, but slat armor is much easier to produce and cheaper. These metal grids help protect military equipment from cumulative grenades, something that especially matters during an urban combat when a vehicle can be fired upon from any direction. It is worth noting that although slat armor is effective against incoming missiles, it doesn't offer complete protection, given that about 50 percent of missile impacts remain unimpeded by the slat design.

 

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Existing technologies for RPG or missile defeat systems include application of slat armor to the military vehicles. The principle of slat armor is to stop the missile before it strikes the body of the target, to crush the missile and short circuit its electric fuze, or to cause shaped charge detonation at a standoff distance, rather than directly on the body of the vehicle. Steel grille armor is said to destroy and interrupt the electrical energy produced by the piezoelectric crystal in the firing head of the RPG. Bar/slat armor is also designed to dud an RPG.

 

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The slat armor is in the form of a rigid grid disposed in a predetermined distance from the vehicle, so as to allow the armor to come in contact with the cover of the RPG in order to neutralize it before the trigger hits the vehicle's body. The distance between the grid and the body of the vehicle is known as the standoff. The slat armor can include a flexible mesh having rigid elements spaced from one another in such a way as not to allow an RPG warhead to hit the mesh without contacting at least one rigid element. Thus, the rigid element neutralizes the devastating effect of the warhead by deforming the conical liner and/or by short-circuiting the fuzing mechanism.

 

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Disadvantages to slat armor are that it adds significant weight to the vehicle, and sacrifices maneuverability. The standoff distance it provides in case of predetonation is too short to be of significant benefit.

 

I will find more of course.

[Damian90]

http://www.defenseindustrydaily.com/baes-lrod-cage-armor-03473/

 

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Those of you thinking that screens aren’t 100% certain to prevent warhead detonation, depending on the angle at which the piezo-electric crush fuze hits it, are correct. Andres also points us to Russian equipment manufacturers external link who tout cage protection against PG-9S grenades, which use much the same concept. Claimed protection is “0.5 probability [DID: 50%] in the areas covered by grill screens.” A protection level of 50% is still preferable to 0% protection, of course, and certain composite armors and other techniques can improve the odds further.

 

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In general, one can expect cage armor or RPG screens to turn only some incoming rounds into duds, or otherwise prevent the explosive from forming a proper shaped-charge jet. If that works, even an RPG full of technically “detonated” explosives that splatter against the vehicle in glops and bang/burn, probably isn’t going to do much damage. Preventing a properly formed shaped charge jet involves a lot of specific science, math, and engineering; suffice to say that there are a number of approaches, and that this is a popular field for additional research.

The offense is also busy, of course. New RPG designs are introducing 2-stage tandem warheads, whose 1-2 punch makes many attempts at passive defense much more difficult. Meanwhile, cage armors will continue to be a popular defensive option against the most prevalent single-warhead RPG threats.

 

We can also look at drawings.

 

So this is the most perfect situation for slat armor, where it will either short fuze the RPG or crush it's warhead thus even if it will detonate, shaped charge jet won't form properly.



And this is how avarage RPG warhead looks like, it have a very thin delicate shell that can be crushed by slat armor.

However tank HEAT rounds have much thicker shell.

 

Which means it's less vurnable to slat armor defeating mechanism.

 

When it comes to ATGM's, many, especially more modern ones have main warhead in the rear of the missile body, thus it will most likely detonate before slat armor will be able to crush the warhead.

 

Here as example Kornet ATGM.

 

Same with tandem RPG warheads.

 

So either precursor charge will be crushed but main warhead will detonate, or main charge will be crushed but precursor charge will detonate uninterrupted.

In tne end ERA, NERA, NxRA, passive composite armor or active protection system will offer better protection against all spectrum of threats than slat armor, of course slat armor will be cheaper and simpler. As I said, no perfect solution to the problem.

[12Alfa]

We used this type. After the atk we clr'd the area and then checked the results. The complete unit had been shredded, tip to tail. My estimation is that a ATGM(even with dual warhead/in tail) would have a difficult time also getting through the wire, but that just first hand knowledge.

[Damian90]

RPGNet is a completely different thing than slat armor. We also use them on our Rosomak APC's. However would RPGNet stop ATGM? It depends, if ATGM would detonate, sorry, nothing will help such lightweight platform, other thing is if ATGM would not detonate, which is possible but a greater standoff would be needed to avoid it touching vehicle main body and thus get detonated.

 

Also these metal elements in RPGNet might cause warhead to detonate, they are there to do exactly the same thing as in case of slat armor, to crush and short circuit single stage RPG warheads.

 

As for first hand knowledge, did insurgents fired at you only from RPG's? Did they used RPG's with tandem warheads like RPG-29? Did they used modern ATGM's like Kornet?

 

There are various types of first hand knowledge, and first hand knowledge can be deceptive, wrong, or not equal or better to theoretical/scientific knowledge. Remember that these protection solutions are made by engineers that in most cases have absolutely no first hand knowledge from battlefields, and all these projects start simply as theoretical works that are slowly moved in to realm of reality.

 

In general I would not put to much faith in to slat armor or RPGNet, these are simple solutions designed to face simple threats within certain limits of requirements, and it's not a wonder that in many cases slat armor is being replaced by ERA for example. A great example here is US Army Stryker, where slat armor is being replaced by SRAT-1 and SRAT-2 ERA.

 

 

Of course ERA is not a perfect solution, but it's good enough, and combined with active protection system, like Trophy, can really significantly increase protection levels of heavy, medium and light weight platforms.

[12Alfa]

various types of first hand knowledge, and first hand knowledge can be deceptive, wrong, or not equal or better to theoretical/scientific knowledge

 

WTF!!!

 

 

Now back to this side of reality.

 

 

I used logic, same as you do, however seems it only works for you,

I need to find anther kind of logic and first hand knowledge it seems

[Damian90]

What kind of logic you used?

 

And first hand knowledge is not always correct, I completely understand from where comes your praise of RPGNet, but your opinion is not necessary correct one.

 

But hey, if you are so sure about RPGNet being able to protect M-ATV or similiar vehicle against ATGM's, you would definately agree for live fire test with you inside? Right?!

 

I would not be so sure if I would be you.

 

Especially considering there are various types of shaped charge munitions with vastly different characteristics, and neither slat armor nor RPGNet were designed to protect against all of such threats.

Edited September 27, 2016 by Damian90

[12Alfa]

but your opinion is not necessary correct one.

 

That works both ways in my world.

[Damian90]

Ok, but can you use something like argument, backed up by at least some source, or scientific backup like projectiles design, protection design, mechanisms within they work and how the interact with each other?

 

Or it will be only like "but I seen it worked against RPG, so it must work agains everything"? 

 

Besides look at Saudi Arabian forces in Yemen, they have some M-ATV's with similiar protection, and this protection is absolutely ineffective against ATGM's.

 

Not to mention that manufacturer itself, QinetiQ says clearly that RPGNet protects only against RPG's, just like it's name suggest.

 

https://www.qinetiq.com/services-products/land/platform-protection/Documents/Qnet.pdf

 

I do not see there anywhere, ATGM's mentioned.

 

And there is more empiric evidence that such kind of protection is designed to protect only against single threat type. RPGNet is not used on MBT's, IFV's, even Strykers got their slat armor replaced by ERA.

 

And there is good reason why, simply ERA or other types of more solid armor provides greater protection against vast spectrum of threats.

 

Of course there is also good reason why they are not used on vehicles like M-ATV, and primary reason are weight limitations.

 

On the other hand RPGNet might be soon become obsolete and be replaced simply by active protection systems, like Trophy-LV or AMAP ADS or Iron Curtain, as they provide much more compact, yet more reliable protection than any kind of slat armor or net armor.

[2-pies]

Thank you all - much food for thought there.

[dejawolf]

the thing with the RPG-7 is that it's warhead is easily defeated by short-circuiting the cone. 

as long as the nose fuse doesn't hit anything, the RPG will be defeated. 

[12Alfa]

Zackley

 

My point was the wire will and does shread light/thin materials, but this it seems lost on a few 

[MDF]

On 9/27/2016 at 0:13 PM, 12Alfa said:

. . .

That said, I been in such a AFV and survived a RPG attack so I'm a big fan [of cage armor], if it were Any type of ERA the civies near us would not be walking on this planet right now.

Of course a expert may chine in as usual , just wait for it

 

On 9/27/2016 at 4:45 PM, 12Alfa said:

various types of first hand knowledge, and first hand knowledge can be deceptive, wrong, or not equal or better to theoretical/scientific knowledge

 

WTF!!!

 

?

[Hedgehog]

I seem to recall the USMC fitted their M60s with an inert version* of the Israeli Blazer Armour, for Op Desert Storm/Granby

Also the Challenger 1 sent there were fitted with a extra Nose Armour pack.

Whether this was ERA or inert, I'm not sure.

 

Think ERA without the noisy filling.

 

Here's a rumour later ERA developments continue to provide protection as the base plate can remain in place after the filling has been "Consumed".

As a .5" thick plate mounted 3, 4, 5 inches away provides up to 5.5" of extra armour. (is about 140mm)