The RPG-7V1 Threat

StrategyPage.com ^ | May 2, 2004:

[Cannoneer No. 4]

May 2, 2004: The American Stryker Combat Vehicle is seeing its first war in Iraq. As the Army’s newest armored combat vehicle, the Stryker has endured its share of criticism, some of which is not without substance.

The Stryker has some major advantages over its predecessors, the M113 Armored Personnel Carrier and the M-2 Bradley Fighting Vehicle, such as speed and its ability to fire its heavy weapons from controls inside of the vehicle. However, its biggest weakness, ironically, is a new version of the four decade old Russian RPG-7 anti-tank weapon.

The Stryker was designed to be a well-protected vehicle capable of fighting in 21st century battlefields. Its armor is composed of a hard steel body enhanced with panels of ceramic/composite armor produced by a Germany company. The end result is armor that is far better than the original M113 APC armor, which was composed of aluminum and gave comparatively poor protection. The baseline Stryker armor gives all-around protection against heavy (up to 14.5mm) machine gun bullets as well as mortar and artillery fragments. An optional “appliqué” armor kit upgrades the armor and enables the Stryker to withstand RPG-7 rounds (just as the same additional armor does for the M-2).

A vehicle capable of stopping RPG-7 rounds sounds like every soldiers dream come true. This certainly proved to be the case for troops using the M-2 Bradley during the 2003 invasion of Iraq. However, all is not as it seems. It is true that the appliqué armor would stop a warhead from an RPG-7. However, it would not be capable of stopping a high-explosive warhead from an RPG-7V1 and 7VR, the latest model of the RPG series of anti-tank weapons. The RPG-7V1 fires three types of ammunition and is arguably the most power[ful] handheld anti-tank weapon on the market. The plain high-explosive warhead is capable of penetrating 600mm of steel armor (twice as powerful as an RPG-7) and the tandem warhead (designed to penetrate explosive reactive armor on tanks) is even more powerful. If hit by either warhead, a Stryker Combat Vehicle would be risk being completely demolished. RPG-7V1s are highly favored by guerrilla fighters and terrorists alike and don’t be surprised if a few Strykers in Iraq fall victim to this weapon in the coming months. The Bradley is also vulnerable to the RPG-7V1, as are M-1 tanks, if hit in the side or rear.

Cheaper copies of the tandem warheads are made in both Iran and China. Two years ago, a cargo ship called the Karine-A was boarded by Israeli commandos who found 50 tons of weaponry destined for Palestinian guerrillas. Among the arms found were large quantities of RPG-7V1s with tandem warhead, which would have significantly boosted the operational capabilities of Palestinian terror groups. The RPGs and their warhead, along with all of the weapons captured, were manufactured and purchased from Iran. Israel had been able to lean on the East European governments to stop most armaments shipments to Palestinian terror groups, but the Iranians consider it their sacred duty to do whatever they can to destroy Israel.

[XEHRpa]

Actually, jet velocities can range, depending on design, from 4 to 11 km/s. The upper limit is governed by a sonic criterion, kind of like the Mach 1 barrier of the liner's metal (the sound speeds in metals are significantly higher than in air). It varies from material to material.

You are right that jet temperatures are measured on the surface, not in the core, but I am confidant to a reasonably high level that code computations corroborate that interior temps are still sub-melting.

And indeed, you are corret that the best way to defeat a shaped charge's jet is to either prevent initial formation (e.g. standoff bar armor, or active armors) or disperse the concentration of the penetrating element after jet formation (reactive or special armors). However, for bullets, as opposed to jets, there are armor designs of ceramic that attempt to resist (rather than disperse) the force of the impact, literally turning the bullet into a flat pancake on the surface of the armor.

[SauronOfMordor]

There's also Chobham armor, consisting of layers of ceramic and steel. Although the exact details of Chobham are still classified, it seems there is something about the shattering effect of the penetrator on the ceramic that dissipates the energy.

I'm not convinced the explanation in Wikipedia has any grounding in reality, though. I'm suspecting that perhaps the passage of the jet thru the shattered ceramic layer experiences an effect similar to the plastic armor used in WW-II on British merchant ships. Consisting of sharp granite stones suspended in an asphalt matrix, it reportedly was pretty effective in protecting against strafing by up to 20mm shells. It appears to have worked by inducing keyholing of the bullets

Which brings me back to my original thought, of what would happen to a shaped-charge jet should it encounter very hard objects (I suggested tungsten carbide particles, but perhaps bits of DU would work better) suspended in an ultra-light matrix that would allow a lot of depth without hugely weighing down the vehicle

[XEHRpa]

I could tell you, but then I'd have to kill you. LOL!

[SauronOfMordor]

However, for bullets, as opposed to jets, there are armor designs of ceramic that attempt to resist (rather than disperse) the force of the impact, literally turning the bullet into a flat pancake on the surface of the armor.

The metallic inserts attempt to do the. The ceramic inserts absorb the energy by shattering, and in the process breaking the bullet into fragments which are then absorbed into the backing Kevlar. See here. The effect is dependent upon the speed of sound in ceramic ( > 10,000 m/sec ) being much higher than the velocity of the bullet it's trying to stop

[Doe Eyes]

Damn Jimmah Cartar/Sen Intel. Comm....w/ their destruction of the intel. services during Cartar's term. :/

We've only have 24 years to fix it. Those Demorats really burn me.

[LibKill]

Armor protection can only do so much for us. We may be approaching the point where the only protection our armored vehicles have anymore is mobility and dead anti-tank gunners.

Mobility is always good. Rome and the Mongol Horde made good use of mobility long before any of us were born.

"Dead anti-tank gunners".

It's time to realize that we cannot allow someone to kill our troops and surrender immediately afterwards. The penalty for killing a U.S. trooper should be immediate execution and desecration of the dead body.

[XEHRpa]

My slow link hung trying to download the PDF you cite. But what I am referring to is (I think) different, and along the lines of that described on pp. 5-6 of

http://216.239.51.104/search?q=cache:h__BuSwY-s4J:www.ahpcrc.org/publications/archives/v13n1.pdf+ceramic+dwell&hl=en

or else

http://www.stormingmedia.us/93/9305/A930593.html

[SauronOfMordor]

Yes, the ceramic dwell phenomenon does occur with a thick ceramic target being hit with a rod at a velocity below a certain threshold, as in the leftmost pic below from this article:

Past the threshold, you start getting penetration (the other pics) and you need a mechanism for dispersing the energy of the projectile over a wider volume of the target

When you started referring to bullets on ceramic armor, I started thinking of the ceramic plates in Level IV body armor rather than tank armor. Yes, there are different effects on ceramic armor that can be as thick or thicker than the length of the penetrator, versus the thinner ceramics for body armor, that necessarily have to be thin and light enough for human wear

[XEHRpa]

True enough. Given vastly different constraints for body vs. vehicle armor, the approaches are, naturally, different.