A source with inside knowledge of the issue sent me this today and I thought I’d share it with you:
Armor kits to deal with the EFP threat to MRAPs is already in production and some kits are in the shipment/installation pipeline to units in Iraq.
The problem with high tempo military operations is that those on the cutting edge will not turn in their current equipment for upgrade when the alternative is using armored Humvees while the existing MRAP vehicles are being upgraded.
Now, we’re still working on finding out what this armor could be — or do — and how many are being shipped. But this is truly an important, and intriguing, development.
– Christian
EFP armor? That’s a hypervelocity copper slug formed by an explosion.
Well, the front armor of the M1 is Chobham composite with dense Depleted Uranium — a mix of layers of metals and ceramics — and that can take a full hit from a tank round. But the weight of that package would be prohibitive.
What about water? Water is notoriously incompressible; a low-weight composite network filled in with water (or some other fluid in some manner) might take the shot and dissipate the energy throughout a long panel.
Imagine kicking a jug of water, where much of the energy is dispersed through water exiting the container.
All I can think of.
I thought I saw somewhere that some form of bullet resistant glass was an effect design against EFP threats. Not sure of anything else but I remember reading about it somewhere.
Actually, I like that idea (water as armor). Here’s why: In the last thread, Christian put out the possibility of slat armor to spall the EFP, but slat armor leaves too much open space the EFP can exploit, even if it could destroy the projectile (which is dubious).
However, there are several projects in the works for concentrated water jets to destroy IEDs: explosions focus a pool of water into a stream which instantly destroys the entire bomb set up, flinging away charges, etc.
Also, because EFPs are copper projectiles, they are relatively weak metal and going extremely high speed. Modern bullets, such as NATO standard, will spall within inches of entering water. An add-on armor could (possibly) break the EFP between a layer of fluid and two ceramic plates: EFP goes right through first layer, slows, hits incompressible fluid, disintegrates, fragments impact second ceramic layer and maybe penetrates with less energy, bottoming out on the actual armor.
It could be a reverse water jet charge, taking in the force instead of thrusting it out.
Or maybe another type of reactive armor, similiar to the waterjet or even a DIME bomb (Dense Inert Metal Explosive, a type of explosive that uses metal dust instead of full shrapnel), where the explosive reaction generates a tremendous outward blast to destroy the projectile.
“I thought I saw somewhere that some form of bullet resistant glass was an effect design against EFP threats.“
That’s interesting.
I remember reading about ‘metallic glass’ which had interesting properties, but I don’t think that was ready for primetime quite yet. Glass has an interesting structure, basically like an infinitely-slow moving fluid.
A glass or glass composite might be a better alternative than my idea. Bravo, sir!
Educational material.
http://www.defense-update.com/features/du-3–07/mrap_counter_ap06.htm
http://www.defense-update.com/products/s/shieldall.htm
http://www.defense-update.com/newscast/0207/news/010207_efp.htm
http://www.defense-update.com/features/du-3–04/feature-light-armor.htm
Roy,
I’ve seen pictures of the prototypes for the new trucks you mentioned. They are being developed along the same lines as the JLTV. They are long haul cargo trucks, fuelers, FMTVs, and troop carriers.
If the army truly has an armor kit they think can stop an EFP, great. The briefing I got in Iraq late last year suggested the only known ways to stop them were impractical for regular use (they involved water, sand, and glass).
Maybe we might not want to speculate too much. Do the hooah’s a favor, yeah?
Joe, besides importing professional military hardware, I don’t think there is another ante for the insurgents/Iranians.
I’m not sure if knowing this information would help the enemy (although there is always the possibility).
Brad there is definitely room for greater ante, as you put it. There are Iranian manufactured ATGMs, MANPADS and more. Basically, the arsenal of Hezbollah could be found in Iraq, should for instance a hot war take place between the US/Israel and Iran.
Mark, you’ll note that I left the option “professional weapons” in there, which covers the ATGMs and manpads.
And if they go that route, knowing about this armor (at least in generalities, not a diagram of weaknesses like the press put out about the Interceptor armor) probably won’t hurt.
Also, though better weapons will make combat more lethal, it will also allow us to strike the sponsor states (unless Obama wins it, then we walk) which could rapidly close off the war by cutting the supply routes to the insurgents/Mahdi/al Qaeda.
This may sound like a stupid idea,but it seems like the best way to avoid EFP IEDs is to stay off of the streets.If maybe when our troops were in the countryside,if they would go off road,& try to avoid the same paths,vary their travels,it could work against the terrorists planting these bombs.Put some MATTRACKS on HMMWVs,& maybe they could operate better off road like our tracked vehicles.Having to use same country roads over & over again just invites IEDs(I understand that it is impossible to go “off-road” in urban areas).
Jeff,
You are correct, bullet resistant glass can be used to counter EFPs but as TB indicated, it is impractical for regular use (you basically have to cover all sides, INCLUDING the bottom).
I know of developements of “electric armor” as part of the Future Combat Systems that distrupts the formation of HEAT jets (very sci-fi, think “deflector shields”), I wonder how well it would work vs EFPs…
>“I thought I saw somewhere that some form of bullet resistant glass was an effect design
>against EFP threats.“
Brad, you damn idiot! Keep your mouth shut if you don’t want soldiers to risk their life for your mouth.
Oops. I meant Jeff. Keep your mouth shut.
I’m sure strapping several tons of tempered glass to each MRAP is going to do wonders for their handling and acceleration.
Maybe the design is a bunch of recycled water bottles, empty of course. In its basic essence, an EFP is nothing more than a larger version of a shaped charge warhead similar to a HEAT round or an AT version of the RPG-7. If they do similar to the Stryker, with a slat armor, it would effective to a point, but others mention the weight factor. Yes the weight does make a difference, but then again these MRAPs were designed for more weight than the HMMWV is.
All you need to do with an EFP is increase the time to contact with the main hull. Just about anything can help with that. Perhaps something the likes of putting a plastic trash can over the vehicle would do wonders. If it can slow down and dissipate the stream of molten copper, it will minimize the damge and it would be cheap enough to take off and replace rather quickly.
I covered the water-as-add-on-armor story here -
http://blog.wired.com/defense/2007/06/urban_legend_ar.html
But an EFP is a kinetic projectile. You can make it more powerful just by scaling it up. Current insurgent EFPs are the size of coffee cans, but they are epxerimenting with much bigger ones. There is no simple answer.
Roy,
You’re almost there, the only way to defeat IED/EFP is to patrol on foot, as the COIN manual suggests. I certainly don’t see how strapping any more armor on these already bloated pigs is the answer.
HEAT/HEAP warhead, a shaped charge warhead focused by a copper or some other metal liner, forming the accellerated superheated gas (plasma) to a focal point. Most warheads of this type have to be an exact distance for maximum effectiveness against armor. This is why TOW missles have the long probe out front, and the warhead of the RPG-7 is actually in the back of the “head” (forward conical part of the RPG-7 is mostly hollow with a pizoelectric detonator in the very tip: Dirt cheap/simple standoff device for a shaped charge). Slat armor either catches or causes premature detonation away from the hull of the vehicle, placing that focal point of the plasma somewhere away from optimal position. THere is a dual charge RPG that is supposed to cause reactive armor to spend itself or blow a hole in slat armor allowing the main warhead to reach optimal position.
An EFP or explosively formed projectile is almost the reverse. Yes it has a minimum effective distance, but slat armor will not protect because the hyper velocity slug will either miss the slats, or blast right through them (not to mention that if it comes from underneath, there IS no slat armor). Instead of having a cone of material helping shape the blast to a point, the material is in front of the shaped charge. WHen the charge detonates the concave disk of metal is shoved forward by the pressure and heat, forging it into a teardrop shape which then continues on at an extremely high velocity (not all that stable, but it doesn’t need to be at the ranges that they are employed). This hot, instantly heat treated, forged projectile cuts through the armor like the old KTW solid copper, teflon coated bullets used to. Its not as effective as a sabot round out of a 120mm smooth bore, but it defeats armor better than HEAP warheads and suffers fewer of the standoff impact issues.
It CAN be defeated, but just like with armor vs. small arms, its a trade off and an arms race. Any armor can be defeated with a big enough gun (battle ship cannon vs. battleship anyone?) and any projectile CAN be defeated given enough armor (ignoring practical applications…Cheyanne Mountain can be considered “Nuke resistant armor” but it certainly isn’t mobile). It all depends on armor tech vs. gun tech, and right now the gun tech has a bit of an edge.
This is one way to defeat EFP attacks found by troops in Iraq:
http://www.strategypage.com/dls/articles/200761622568.asp
Accidental Discovery Aids In EFP Protection
by James Dunnigan
June 16, 2007
Everyone knows explosively forged projectiles (EFPs) are an effective weapon against vehicles in Iraq. However, troops in the field have noticed that although EFPs go through metal armor, often glass laminate armor (aka glass ballistic laminate armor) will stop them. Troops report that the EFPs would not go through the bullet proof windows, which are made of glass laminate. However, the glass laminate only works once. When an EFP strikes the glass, the glass “spiderwebs” (shatters laterally and vertically) but it stops the penetrator. Of course it only needs to work once
Trent,
That looks like the article that I read. Thanks for finding that.
Once again I am disgusted with our “technology folks,” DARPA, ONR, etc. Bah!
Lets keep this simple. Chobham Armor quite frankly is vastly inferior to ANY glass.
The reason is the difference between hi velocity and hyper velocity. The “break point” is 2000fps.
I can put a penny through an inch of stainless at 3700fps.
I don’t want to “teach tango’s” jack.… But be aware that the “ladder of armor” is quite simple.
In last place, Metals
In 2nd place, Ceramics (which are in fact glass.)
In 1st place, Glass.… Glass does not “melt” so to speak like the last and second places. Anything over the Hyper, you need glass.
When I was “trained many moons ago,” we were taught to use manhole covers. yep, thats right, whats gonna stop that? hmmm? why do you think the SS Welds them shut when there is a motorcade?
Anyways, I have already Patented two hand in hand systems to defeat not only detonation shearing forces, but over and underpressures. The second one specifically deals with efps.
**Note– If you mount 3 inches thick laminate glass to that beast (which I truly, truly hate!) I’d be surprised if it even moved! How much cost in fuel alone (not to mention the “sticker price”) is gonna just get chucked out there?
The Mrap is stupid, plain and simple. Ive been saying it for a long time, and now were gonna mount about what? 25K Pounds of Glass on it as well? What the heck are we thinking? No wonder were not “quite” the super power we used to be.
Between fuel, cost for glass, etc, etc.…. why not build something that just WORKS!
Best, David
FYI from MSNBC, the cut in of improved armor variant MRAPs is being reported on from Kuwait:
>Upgrades readied for battle
>
>Meanwhile, at Camp Arifjahn in Kuwait, the
>military is reinforcing some of the
>blast-resistant with additional side armor
David Woroner,
Your contentions are not supported by the facts on the ground in Iraq.
MRAPs save lives and in their role as troop transport thay are superior protection than anything else on the battlefields there — up to and including a 63 ton Abrams — in protecting them from the IED threat.
In addition, the usefulness of glass laminate in stoping high explosive shapred charges and EFPs have been proved on Iraqi battlefields multiple times.
The following are links to photos of battlefield damaged Abrams, Humvees, MRAPs and a glass laminate armor protected D-9 bulldozer.
1. The picture at this link shows a 63 ton Abrams tank destroyed by a large IED in Iraq.
http://www.freerepublic.com/focus/f-news/1602087/posts?page=9#9
2. The picture at this link shows a 63 ton Abrams takn destroyed by an “IED Daisy Chaign” of 152mm artillery shells:
[REMOVED BECAUSE LONG LINK CAUSED FORMATTING ISSUES: Editor]
3. The pictures at this link show an armored Humvee hit by a large IED and a RG-31 MRAP hit my a similar sized IED:
http://www.freerepublic.com/focus/f-news/1602087/posts?page=1#1
4. This link is to a series of pictures of the glass laminate armor of a D-9 Bulldozer struck by a RPG high explosive shaped charge warhead. Similar results have been noted on glass laminate armor by EFP hits:
http://www.liveleak.com/view?i=5ea323d564&to_friend=1
This is the text that went with that photo:
>D9 CAT Takes RPG Hit and Lives
>In early 2003, the U.S. bought nine 62 ton D9
>armored Caterpillar bulldozers into Kuwait for
>the Iraq campaign. The D9s, and their Israeli
>made armor kit, were purchased because of the
>Israeli success with the dozer in urban warfare
>against Palestinian terrorists. America had used
>the D9 during the 1960s in Vietnam, but after
>that only used the smaller (35 ton, with armor
>kit) D7. The D9 was not needed for urban fighting
> in Iraq during 2003, but was found very useful
>(much more so than the smaller D7) for combat
>engineering tasks. The D9 quickly cleared
>highways of debris and built temporary roads for
>combat vehicles. One D9 was thought to be as
>useful as four D7s, and there is a lot of
>enthusiasm among combat engineers to keep the
>D9s, and get more of them. In 2004, the D9s were
>used for combat operations in places like
>Fallujah.
>Photos by LTC Norm Root
5. The photos at this link shows a US Marine 6x6 Cougar MRAP struck by a 200-300lb IED in western Iraq. None of the crew was killed in this attack:
http://eureferendum.blogspot.com/2007/08/imagine-this-was-snatch.html
Your contentions about MRAPs and the protective properties of glass laminate armor are not supported by the facts anyone can find using a google search engine.
You will find this YouTube Movie useful.
Abrams-in-Iraq
http://youtube.com/watch?v=EP3G2bHs6Ys
Badly need your help. A physicist is an atom’s way of knowing about atoms.
, Thaddeus.
I am from Gabon and also now am reading in English, please tell me right I wrote the following sentence: ““
Best regards
Dear Christian,
I must share some armor developer’s comments“
1) An EFP is not a “bullet”, it is a piece of copper formed by an explosion rather than hammer forging or casting. Copper simply splashes on the surface of harder materials unless it’s mass is great enough to distort the structure of the ceramic or glass. We have all seen lead or copper bullet impacts on steel and this is the same effect.
2) To stop a bullet you de-spin it and deform the point to cause greater resistance to passing through the armor material. To stop a shaped charge or EFP you splash the “jet” or forged fragment on glass or ceramic and then absorb the mass related force with steel or S2.
One guy said he stopped .45 slugs with marbles…a form of vehicle armor which contained hundreds of marbles was patented and went away. I have stopped 5.56mm ball with two layers of bathroom tile and some sheet metal backing. These are perfect examples of 1 and 2 above.
Carry on, you are very knowledgeable…nobody can know everything, not even me on the subject of armor and we own high speed cameras, thermal imagers and accel test rigs.
Very truly yours,
Howard D. Kent
ARMOR Development GROUP, LP