CMSF2 RPG-7 & Warheads, Slat & ERA Armor - Capabilities and Limits Player Guide

[tpr]

Rule Number One:You never can judge the threat of a RPG-7 without taking its warhead into account. While the launcher system appears almost unchanged for many decades, warheads evolved over the time and in CMSF2 you will encounter many different ones with penetration values ranging from 280mm up to 700mm RHA.

Starting with the PG-7V and the PG7VL, these are simple HEAT rounds whith the VL being the improved more powerful version. They come with the iconing mortar/rifle grenade shaped warhead everybody knows from movies, games, and photos. It´s basically the most widespread warhead on the world and saw widespread use in Afghanistan and Iraq which prompted the Coalition forces to issue "up-armor kits" for their vehicles with addon armor systems like ERA blocks or the Slat/Cage Armor (which was already introduced in a smiliar fashion by German Forces back in WW2.) Both armor systems have the goal to "pre-detonate" the HEAT grenade before it can make contact with the main hull and inject its charge into it. You will see in this test that both systems work although success is definitely not guaranteed thus don´t "count" on them. Even may these armor systems look imposing and bulky they are just raise the survivability odds in situations you never wouldn´t like to find your vehicle in the first place. Also naturally the grenade can always hit parts that are not covered by both systems. You will also see that the impact angle contributes to the system´s effectiveness.

However the Syrian Forces and also the UNCON forces in CMSF2 evolved and now possess warheads that can overcome these two systems like the PG-7VR which comes with a Tandem warhead that has the ability to defeat counter measures first with a smaller charge before the main charge makes contact with the main hull of the target. Furthermore they even more powerful than previous warheads also against conventional armor. In other words ERA or Slat is pretty useless against them (ERA at least is able to substract of its penetration value). The vastly different shaped PG-7VR is a very lethal threat to almost any vehicle in CMSF2.

Furthermore there are the HE and Thermobaric Warheads which are designded for anti-personnel or attacking fortifications. So in CSMF2 you want to use them against infantry, especially in buildings. You can engage unarmored or very light armored vehicles but other than that they are quiet ineffective against defeating the armor. However they can damage optics and other systems outside of vehicles with their HE effect. It may also cause crew interference due to psychological stress and could trigger retreats (inexperienced, nervous crews). So it may be a viable option to use these against heavier targets via the target command to degrade their combat effectiveness.

Also in the second video when firing from distant ranges you may notice a complexity of CMSF2 that isn´t represented in many games. While the RPG is quiet unprecise at greater ranges, the AI soldiers aren´t bricks, they "learn" with every suceeding shot and thus accuracy isn´t calculated always from the scratch (this is true for all weapon systems by the way). What I often did (better said not did) is that when I heard the sound of flash of an AT being fired towards my vehicles which then missed, I found myself relieved thinking "missed, everything fine again" but especially with RPG teams being able to carry alot of ammunition you may consider to reposition your vehicle as these shots may become more precise pretty quick maybe the 2nd shot already will be enough.

Also keep always in mind: When the enemy AI fires something at you it does that most of the times because it thinks it can hurt you and achieve this with a considerable precision. So when unknown AT ordnance impacts beside your Abrams it may be able to hurt that Abrams and that the threat may be close by. The chances that this was just a guy who found an old ineffective HE warhead in his basement went to the streets and casually fired it towards your Abrams from 600m just to return to home after that is very slim.

 

Edited December 18, 2018 by Captain Reyes

[MikeyD]

Quote

Both armor systems have the goal to "pre-detonate" the HEAT grenade before it can make contact with the main hull

Actually, that's technically incorrect.
The (real world) purpose of the slate cage is to dent the sheetmetal cone of the incoming RPG warhead and short out the electrical connection from the piezoelectric fuse in the nose to the warhead base, causing the warhead to fail. That's why the slats are spaced a bit less than the width of an incoming RPG round. Pre-deployment tests demonstrated that slat cage had a roughly 50% success rate. The very first RPG round to hit a Stryker slat cage in Iraq detonated against the forward cage and pierced the front hull between the MEXAS ceramic tiles, severing engine cooling lines.

When Chinese-made RPG rounds began appearing in Iraq that was the beginning of the end of the slat cage. Because the Chinese round doesn't have the fusing flaw of the original RPG round. You'll notice US Stryker in Iraq during the most recent battles to oust ISIS lack the slat cage.

See the illustration of RPG warheads. That Chinese 'airburst' warhead is interesting. All it is is a delay fuse and a metal ring around the nose of the projectile which causes it to skip and tumble on hitting the ground instead of penetrate.

 

[HerrTom]

I also believe the explanation of ERA is also slightly incorrect. ERA is an explosive sandwich, with metal plates on both sides. When triggered, the plate is forced into the metallic jet from the HEAT warhead, causing it to deform and break up, reducing it's penetration ability (a fact which makes me wonder how effective ERA actually is on thin skinned vehicles like the BMP-3). So ERA doesn't really pre-detonate the incoming warhead, it's usually triggered by it!

This is the mechanism which allows ERA to also be effective against kinetic rounds too.

[IICptMillerII]

35 minutes ago, MikeyD said:

Pre-deployment tests demonstrated that slat cage had a roughly 50% success rate.

This is one of the main reasons the slat cage armor was short lived. It wasn't overly effective, and was more of a stop gap before ERA was more widely introduced on lighter vehicles like the stryker and Bradley. ERA was slower to be adopted partly because of the extra weight added, and a focus on defeating IEDs instead of RPGs.

23 minutes ago, HerrTom said:

a fact which makes me wonder how effective ERA actually is on thin skinned vehicles like the BMP-3

Very much depends on the warhead. Single warheads stand a pretty decent chance of being defeated by ERA, whereas more modern tandem HEAT warheads are designed to defeat ERA, and top attack designed to avoid it all together. Though it's not impossible for ERA to defeat tandem heat warheads. I've seen a javelin missile or two defeated by the top turret ERA on a T-72 in SF2. I think the logic behind applying the ERA is that even if it only improves you chances of survival by 10% (or some other marginal percentage) it's certainly better than nothing. 

That said you can certainly make the argument that the added weight from ERA degrades other functions of an IFV to make it not worth it. For example, some IFVs that are amphibious lose that capability once ERA is applied. ERA maintenance is also a pain, and adds a larger workload for the crew. 

[tpr]

If you really interested into the matters do your own research at best with military academic resources for example like this one: https://apps.dtic.mil/dtic/tr/fulltext/u2/a567418.pdf but you definitely will find more and better ones.

Edited December 18, 2018 by Captain Reyes

[HerrTom]

6 hours ago, IICptMillerII said:

Very much depends on the warhead. Single warheads stand a pretty decent chance of being defeated by ERA, whereas more modern tandem HEAT warheads are designed to defeat ERA, and top attack designed to avoid it all together. Though it's not impossible for ERA to defeat tandem heat warheads. I've seen a javelin missile or two defeated by the top turret ERA on a T-72 in SF2. I think the logic behind applying the ERA is that even if it only improves you chances of survival by 10% (or some other marginal percentage) it's certainly better than nothing. 

Indeed this may be true, but I think the key thing is that even traditional (i.e. non-tandem) warheads aren't really defeated by ERA, just diminished. I found a (wicked cool) shadowgraph showing the instability of the jet as it passes through an ERA panel.

There is still kinetic energy there - just less.  My speculation was whether you could plant a panel on a BMP-3 that is both A) Powerful enough to disrupt the jet such that it can't penetrate the Papier Mache that the designers call "armour" and B ) isn't so powerful that it caves in the hull.

Edited December 19, 2018 by HerrTom
Edit, because it posted instead of letting me edit!

[IICptMillerII]

38 minutes ago, HerrTom said:

warheads aren't really defeated by ERA, just diminished.

I agree, diminished is a better choice of word than defeat. 

[Erwin]

Very useful info.  Thanks...

[LuckyDog]

The impression I got from the Gulf War 2 exhibit at Bovington Tank Museum was that the slat armour on the Warriors was doing a pretty good job of catching incoming RPGs - they cited a case where 14 (I think) were removed from the slats on on vehicle! They didn't mention what happened if it hit the slat directly and detonated. I have no idea of how representative this was of reality.

[Combatintman]

34 minutes ago, LuckyDog said:

The impression I got from the Gulf War 2 exhibit at Bovington Tank Museum was that the slat armour on the Warriors was doing a pretty good job of catching incoming RPGs - they cited a case where 14 (I think) were removed from the slats on on vehicle! They didn't mention what happened if it hit the slat directly and detonated. I have no idea of how representative this was of reality.

14 seems to be a magic number or my memory is faulty (more likely) but I seem to recall we had a Viking with bar armour in Afghanistan during my first tour in 06-07 that shrugged off 14 RPG strikes.