HEAT warhead parameters (OA)

Hello there guys,

With the release of Operation Arrowhead, ArmA2 ammunition now has a new parameter available: penetrability.

This new addition prevents small calibers to penetrate armor thus killing the crew of the vehicle, the destruction of a battle tank with 200 low caliber rounds, etc. It also allows bullets to go through a brick wall if its speed and caliber allow it, just to let you know an example of how this new feature works.

However there is an issue with High Explosive Anti Tank (HEAT) warheads. Currently this type of ammunition does not have a value for penetrability: it explodes at the lightest armor without damaging the targeted vehicle. You can compare this behavior to a grenade launched from a rifle grenade launcher. The only parameter used by these shells is the speed at which the warhead is fired.

It would be good and constructive if someone with some good knowledge of how this ammunition works could help BIS.

1. What should the penetrability of an HEAT warhead be compared to a SABOT one? 50% ? 25%?

2. How does it behave in older tanks such as the T-55 or T-34? Whats the penetrability of the HEAT fired from these tanks since they have smaller main guns? And for the more modern ones such as the M1 or the T-72?

All information will be extremely helpful to allow for a better simulation of tank warfare in the game.

HEAT rounds from tanks behave differntly to a HEAT projectile fired from say a launcher.

I believe the HEAT round from the early T-55's had a 100mm rifled gun, but a rifled barrel will have a negative effect on the performance of the HEAT projectile when it hits the target.

The HEAT round from early T-55's had to be specialy adapted for the rifled barrel.

I think if I remember right that the T-55's Heat round would travel at around 1000 m/s..

A SABOT round is by design far more accurate and uses kinetic energy to simply punch its way through armour using a far higher MV and is far superior in its ability to penetrate..

It's been a while since I served on tanks so will have to look up a few of my old manuals to get something concrete..

Edit, quick check tells me that the T-55's main ability today would be mainly effective against light to medium armour.

It's HEAT round had a max range of 2000-2500 m.. and could penetrate about 380mm of standard armour at 1000m.

I'm not seeing this ineffectiveness. Just loaded up in the editor an M1A2, and 12 T-55s. HEAT rounds defeated all armor arcs within 2 hits. Usually 1 hit and the crew baled, 2nd hit was a catastrophic kill every time. Seems pretty effective to me.

You can get as complex as you want, but I think it would be more efficacious to simply compare penetration statistics vs. RHA and the RHA rating of vehicles. Ceramic, laminated, spaced, etc have different properties vs. different types of projectiles, just like there are factors between different types of rounds and their system of delivery that impacts the result. I would be happy with a simple working scale of armour protection for vehicles and destructiveness for penetrating ammunition, not even taking into account any of those obscure factors.

Likely, the missing of that config entry for HEAT ammo was not by design and is simply an oversight or the result of some other problem.

I'm not seeing this ineffectiveness. Just loaded up in the editor an M1A2, and 12 T-55s. HEAT rounds defeated all armor arcs within 2 hits. Usually 1 hit and the crew baled, 2nd hit was a catastrophic kill every time. Seems pretty effective to me.

There's already a video demonstrating that a T-55 is not able to destroy a simple HMMVEE even at close range. I will try to find it...

EDIT:

Here it is:

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Likely, the missing of that config entry for HEAT ammo was not by design and is simply an oversight or the result of some other problem.

It has been confirmed to me that this problem is indeed a bug.

Heres a great resource for this. Gives frontal armour values and at the bottom weapon penetration values from APFSDS to HEAT to 50 cal.

http://collinsj.tripod.com/protect.htm

Some HEAT rounds can penetrate similar or better than KE penetrators, what makes them less effective is that it is easier to make armour that resists cumulative energy based threats.

1. What should the penetrability of an HEAT warhead be compared to a SABOT one? 50% ? 25%?

Performance depends on caliber, liner material (i.e. steel, copper, tantal) and cone angle, explosive filler .. With the metal jet reaching velocities in excess of 7000 m/sec, penetration performance for HEAT projectiles does not decrease over distance, unlike the case for KE rods. Sabre already wrote about the disadvantage of HEAT vs APFSDS against modern MBT armour. Another drawback not related to penetration; HEAT projectiles are slower than AP(FS)DS, which translates into higher trajectories and increased lead when shooting at moving targets. For 100mm BK5 (UBK-4 HEAT) time to target difference is about +1.7 sec @ 2000m, or +3.6 sec at 3000m, when compared to 100mm BM-8 APDS.

2. How does it behave in older tanks such as the T-55 or T-34? Whats the penetrability of the HEAT fired from these tanks since they have smaller main guns? And for the more modern ones such as the M1 or the T-72?

100 mm UBK-4 HEAT-FS

Vasiliy Fofanov's Modern Russian Armor Page

Interesting:

HEAT-FS rounds were also substantially more accurate than APFSDS (which might also be surprising to a Western reader). This is reflected in the Soviet deviation criterion, which was more strict for HEAT rounds (0.21 mil) than for APFSDS rounds (0.25 mil). However, in practice HEAT-FS rounds were even more accurate. As control trials of a random mass-production T-64A held in the 70s (the details of which were made available to the author) indicated, while APFSDS rounds hugged the outer bounds of acceptance criterion, HEAT-FS rounds actually demonstrated the average deviation of well under 0.1 mil!

Very nice data TangoRomeo.

I would also like to ask people to check the HEAT ammo behavior on every vehicle that uses it. While the M1 seems to be working properly, the T55 does not seem to be having the same performance. Other tanks might also have this problem, check it out.

Suggestions:

Go to the editor, place the vehicles that use HEAT rounds and several lightly armored and unarmored vehicles as targets. Fire from different angles, test all vehicles and report the results there.

(I do not have Operation Arrowhead to conduct the tests)

in RL no one should survive in that humvee with side hit by 100mm T-55 cannon loaded with HEAT round. Humvee would probably open up like a tin can. Fragments would kill the occupants and very thick armor doesn't provide any security at all against such round.

Hopefully this will get fixed in one of the upcoming patches. There are numerous studies on HEAT/Sabot rounds, also available on net.

I've blown up tanks with FIM-92F Stingers. (well, not blown up, but the crew decided to evac)

Mind you, it wasn't a very modern tank (T-34).

It has been confirmed to me that this problem is indeed a bug.

:butbut::butbut:

oh well,we have a bug right there.BIS.....fix it plz :o

And give us proper armour/penetration system please....

How do I use this penetrability? Is it used in configs or .bisurf files?