Anti-tank rockets useless

[Wolfie]

...keeping in mind that the gun's very job is to kill M1's, not fluff pillows.

 

Lets see some proof of that. After all, the gun can supposedly only pierce about 60-70mm RHA at 500 meters. Hint: M1 side armor about 6 - 700mm RHA? Frontal: Above 800mm RHA? Even if you knock out its track on one side, maybe damage periscope, etc., its weapons are probably still functional, and you are now very much in its weapons range, which can include .50 machine guns, proximity fused HE shells, canister rounds, etc. As long as the crew, and some weapons function, its not dead. And a well trained crew is not going to abandon it, but wait for reinforcements and repair, if at all possible.

 

Personally, I don't think the gun can do more than take out APCs. Mavericks, rockets, etc. are what is made for taking out modern tanks. And thats why we need a realistic armor system in this sim.

[maturin]

For perspective, the RHA penetration of most 80ish mm HEAT rockets is 300-500mm. That's many times more than the GAU-8 at point blank.

 

But back on topic, I don't think an 80mm HE rocket would even scratch a tank. It's really just a little charge designed to throw fragments around, knocking over cinderblocks and infantry.

[Wolfie]

HE, no. AP, now that's another thing.

 

But yeah, modern tanks laugh at HE, unless it happens to break the periscope windows or mangle an antenna. Then you have some angry tankers.

 

I think the Arma forums have some really good discussions on armor values and penetration by various weapons. I keep meaning to check it out. I know the ACE2 team made a pretty good armor system for the vehicles vs. all kinds of weapons. I believe a guy named King Homer did it for them. He seemed to know what he was talking about.

[Eddie]

Both correct. The GAU-8 should not be able to kill an MBT such as the M1 as it can in the sim, a mission kill is the most you can hope for.

 

Wolfe, don't underestimate the value of a mission (mobility/weapon system) kill. Of course it's likely that the tank could be repaired, but the fact that that bit of kit is out of action for a few hours can indeed make a difference, in fact a few mission kills can be more effective than blowing them to pieces. You're keeping other assets occupied taking care of casualties and/or repairing damaged equipment. Something with only happens with trained military forces, the average insurgent doesnt really seem to care about such things.

 

The bulk of this arguement, which keeps coming up, seems to hinge on the different definitions of "kill" people have. All I'll say is that what counts as a kill in the sim and what counts as a kill in reality are not the same. And furthermore what counts as a kill in the sim is something that isn't that common in reality, you also don't get the clear feedback when you kill your target IRL, as you do in the sim.

 

Hopefully in the future the damage and weapon model will be improved and we'll see more varied ground unit and structure damage and things like fragmentation which would make things like MPSM rockets and air burst weapons available, as well as make the current weapons more effective.

[slug88]

Hint: M1 side armor about 6 - 700mm RHA? Frontal: Above 800mm RHA?

 

That's nice, how about the top armor? As in the part that would actually get shot at in a gun run by an A-10?

[maturin]

I have heard (not from an authoritative source) 20mm for thickness of Abrams roof armor, but this is surely absolute thickness, rather than RHA equivalency. Parts of the roof have a chance of withstanding RPG warheads that penetrate 300mm RHA. Also, the effective thickness would be greatly increased because of the angle of incidence of rounds, plus danger of ricochets.

 

Edit: The ACE2 mod for ArmA 2 estimates 40mm RHA equivalency for roof armor, so conceivably vulnerable to the A10 at short ranges.

[marcos]

I've been considering the heating effects of a 2s burst and stopping 160 DU rounds weighing 1lb each and travelling at 1070m/s + the speed of the diving aircraft. That would probably start a skin fire and may force the occupants out. Not sure about how they ventilate themselves either.

 

There's no way it would penetrate the armour but as regards destruction resulting from a fire and subsequent overheating, I'm open to argument.

[159th_Viper]

After all, the gun can supposedly only pierce about 60-70mm RHA at 500 meters. Hint: M1 side armor about 6 - 700mm RHA? Frontal: Above 800mm RHA?

 

Forgetting the roof armour, eh? Do you have any idea how weak said roof armour is? Try 50mm. Not to mention the hatches and other soft spots on the roof. And then there's the engine compartment which is relatively weakly armoured: 50-100 rounds in the engine block and all you're left with is an expensive paperweight.

 

When I said the A-10 will clean a M1's clock I was not referring to a 30-degree side/frontal gun-run ;)

[OutOnTheOP]

Regarding the 30mm vs rockets in anti-armor use, consider:

 

1) that the RHA equivalents of any given armor layout are *not* the same for both KE and HEAT. Generally the modern composite armors are 50%-100% more effective against HEAT than against KE, so a KE weapon with 100mm RHA penetration is just as effective in most cases as a HEAT one with 200mm penetration. Reactive armor- ubiquitous on Russian designs- makes the comparison even harder, as it's extremely effective against HEAT but does almost nothing to KE

 

2) the 30mm has essentially no chance of killing a tank from the front. However, even modern tanks like the T80U and M1A1HA generally have between 60-90mm RHA on the hull rear; the engine deck is generally understood to have less than that, but finding numbers is tough (and of course any numbers you find are suspect). A 45* or steeper diving attack onto the rear quarter of a tank can indeed find plenty of places- even on a modern tank- where 30mm AP can penetrate. Perhaps not into the fighting compartment, but certainly into the engine compartment. On the other hand, the front quarter (and turret sides) of even the old T54 were NEVER considered valid targets for the GAU8, even when it was first designed. Don't expect frontal attacks on tanks to work. But don't assume that this means tanks cannot be destroyed with GAU8.

 

3) I seem to recall an M1A1 that was disabled (not destroyed) by 25mm fire from a Bradley to the rear of the engine bay; it may not be a catastrophic kill, but perforating the engine bay and messing up the engine is going to take a day or two to recover- and you only keep so many spare engines laying around. ....and that's assuming the engine doesn't catch fire, in which case you may well lose the entire vehicle.

 

4) Obviously Maverick is going to be the better option. But you can only carry so many, there are only so many available, and they're expensive and hard to make and more difficult to transport compared to a couple hundred rounds of 30mm AP.

[OutOnTheOP]

M1 side armor about 6 - 700mm RHA? Frontal: Above 800mm RHA?

 

Wait, turret sides have armor almost as heavy as turret fronts?

 

Not from what I've seen; M1 turret side armor is more in the 300mm RHA (vs KE) range, even in the latest versions. Which is still a good sight better than the T72/T80/T90 family, with closer to 150-200 RHA. M1A1(HA) turret FRONT is in the 850-950mm range, while M1A2 SEP is closer to 950-1000.

 

All numbers are, of course, from open source media, and rather doubtful (but the best available), though these numbers do make sense: they are roughly equivalent of what turret FRONT armors were in the 70s, before the advanced armor packages were put in. Side armor generally doesn't include the thick arrays of advanced composite armors.

[marcos]

Regarding the 30mm vs rockets in anti-armor use, consider:

 

1) that the RHA equivalents of any given armor layout are *not* the same for both KE and HEAT. Generally the modern composite armors are 50%-100% more effective against HEAT than against KE, so a KE weapon with 100mm RHA penetration is just as effective in most cases as a HEAT one with 200mm penetration. Reactive armor- ubiquitous on Russian designs- makes the comparison even harder, as it's extremely effective against HEAT but does almost nothing to KE

You sure about that?

 

http://www.economicexpert.com/a/Composite:armour.htm

 

 

That aside, you do wonder why they don't put more armour around the engine. And what was a Bradley doing fighting an M1?

Edited August 26, 2012 by marcos

[ShuRugal]

That aside, you do wonder why they don't put more armour around the engine.

 

hard for a radiator to dump waste heat when it's wrapped in a steel box with no airflow. It'd also be a puzzle to work on an engine that was behind a slab of armour.

 

And what was a Bradley doing fighting an M1?

mistaken identity and/or shitty aim on the gunner's part.

[Wolfie]

@OutontheOP - Oh, I somewhat agree with you on KE and Chem values, but ERA is effective against kinetic - the explosion tends to fracture the spike and/or force it off course, causing a glancing blow. Though yeah, it probably isn't as effective as it is against chem.

 

Also, I found an interesting table.

 

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

 

As for top armor, that's pretty hard to find. All I can find so far is about 40 to 50mm (KE? Chem? Actual?) estimates for M1 top armor. The Army seems to want to keep this value a good secret. Now we have to consider its a glancing blow, probably at about 30 degrees.

Edited August 26, 2012 by Wolfie

[OutOnTheOP]

You sure about that?

 

http://www.economicexpert.com/a/Composite:armour.htm

 

 

That aside, you do wonder why they don't put more armour around the engine. And what was a Bradley doing fighting an M1?

 

Sure about what? That any given armor may have higher or lower RHA equivalencies depending on whether it's hit by KE or HEAT? Even the link you sent supports that.

 

Or do you mean sure that ERA is largely ineffective against KE, which, well, it IS: it's certainly going to provide SOME protection- but then, so would strapping phone books or feather pillows to the side of the turret. Point is, ERA is MUCH more effective against HEAT than KE. And the Russian's claims of their "secret sauce" ERA's effectiveness against KE must be taken with a grain of salt; they're trying to SELL this stuff. That aside, they've pretty much out and out admitted now that Kontact doesn't work against the M829A2 or M829A3 long-rod penetrators. If ERA was going to work well against ANY KE round, you would expect it would be against projos with a high length-to-diameter ratio. (*edit* because it's easier to tumble or break them than short, squat rounds)

 

Also, that link doesn't address side nor rear armor values (to which I'd note my earlier comment was a fairly generous assessment of turret side strength... there's plenty of open-source out there indicating that the T72 series has parts of the side (mostly lower hull sides, around the running gear) as thin as 20-30mm RHA equivalent.

 

*edit* Wolfie, I'm pretty sure that table is pretty SWAG estimate, and I'd guess it was made by an American or Brit (westerner, anyhow) with no military background: it vastly underestimates some of the Russian armor values (well, the early stuff, anyhow. It still falls in the trap of huge estimates to T90)

 

...though not as badly as Marcos' link OVER estimates the T80U and T90. Seriously... T90 is just a trade name for the T72BM. It's JUST a fancied-up T72. I find it hard to believe that at a mere 40 tons, and without having armor so overinflated that it looks like the Staypuft Marshmallow Man, it's supposed to have 4 times the protection level of the baseline T72. Not to mention, better turret frontal KE defeating performance than the Leo 2A6 and M1A2SEP? Highly doubtful. HIGHLY doubtful.

Edited August 26, 2012 by OutOnTheOP

[OutOnTheOP]

hard for a radiator to dump waste heat when it's wrapped in a steel box with no airflow. It'd also be a puzzle to work on an engine that was behind a slab of armour.

 

 

mistaken identity and/or shitty aim on the gunner's part.

 

 

Exactly; never said it was INTENTIONAL, just that it happened. I suspect it was close-in city fighting, with the two vehicles VERY close together (like a tank length or two): the roof-mounted sight may have had a clear line of sight over the M1, but the cannon did not. But that's spectulation; either way, a Bradley hit an M1 and knocked out the engine.

[WildBillKelsoe]

It took only 6-7 with the MK151s. Killed 3 tanks with 20 rockets.

 

The best method seems to be to spam ripple pairs rather than ripple singles because it increases the chance of a hit.

 

Also to minimize sway in case you shoot one side only. try doing it in the mustang to know what I mean.. I usually set DSMS to RPL PRS quantity 2.

[marcos]

Sure about what? That any given armor may have higher or lower RHA equivalencies depending on whether it's hit by KE or HEAT? Even the link you sent supports that.

I was looking at your argument that newer Russian tanks have virtually no ability against KE. Frankly I have no hard evidence but I suspect that others don't either. Weight and RHA are only linked when discussing the same type of armour.

Edited August 26, 2012 by marcos

[maturin]

I'm not terribly skeptical about Russian claims of new ERA effectiveness against KE rounds. That stuff is getting advanced, with radar-controlled pre-detonation and such.

 

The Israelis say that their ADS systems can knock down sabot rounds, after all.

 

But this is rather moot, since ERA will be next to useless against the GAU-8, which is going to hit dozens of times, finding the gaps in coverage and hitting blocks twice.

[Wolfie]

 

*edit* Wolfie, I'm pretty sure that table is pretty SWAG estimate, and I'd guess it was made by an American or Brit (westerner, anyhow) with no military background: it vastly underestimates some of the Russian armor values (well, the early stuff, anyhow. It still falls in the trap of huge estimates to T90)

 

...though not as badly as Marcos' link OVER estimates the T80U and T90. Seriously... T90 is just a trade name for the T72BM. It's JUST a fancied-up T72. I find it hard to believe that at a mere 40 tons, and without having armor so overinflated that it looks like the Staypuft Marshmallow Man, it's supposed to have 4 times the protection level of the baseline T72. Not to mention, better turret frontal KE defeating performance than the Leo 2A6 and M1A2SEP? Highly doubtful. HIGHLY doubtful.

 

Lol, yeah, we really need to find an expert on this. I did a few hours of research so far on google, and its really hard to find anything solid, especially top armor. Plus, we have to understand what normally happens when the bullets hit at sharp angles ( which is the usual ), and does the mass attack of 70 rnds/sec increase damage in of itself ( heating / softening, fracturing, etc. ). Hopefully, ED can pry some information out of someone ( or we can just wait for data from the coming Iran War :music_whistling:).

[marcos]

I imagine that defence ministries aren't terribly eager to release information on their MBT's weak points.

[maturin]

Armor estimates are easy to find, but rear and top armor is a pretty big mystery. The most detailed estimates are for the professional tank sim Steel Beasts.

 

Ain't no auto cannon getting through that side armor, except to pick at that tiny spot in the hull.

http://www.steelbeasts.com/sbwiki/index.php/Image:M1A1_HA_frontLOS.jpg

On the other hand the commander's hatch looks quite vulnerable, once you close within 1000m.

http://www.steelbeasts.com/sbwiki/images/3/30/M1A1_HA_sideLOS.jpg

 

The T-72's top armor actually looks like a pretty tough nut.

http://www.steelbeasts.com/sbwiki/images/3/34/T72Barmour.jpg

 

Now let's refer to the coloring book, which claims that the top armor of the hull is too thick to penetrate. And it also mentions that trying to track a tank with what is technically just a big firearm is a dumb idea.

http://s207.photobucket.com/albums/bb48/hamm172/WORLD%20OF%20TANKS%20STUFF/?action=view&current=T-62_CB_page7.gif

Edited August 26, 2012 by maturin

[luza]

IIRC Mk5 = HE, and MK151 is Anti armor. :megalol:

[Eddie]

IIRC

 

You do not. Mk-5 is HEAT and M151 is HE fragmentation.

[marcos]

You do not. Mk-5 is HEAT and M151 is HE fragmentation.

I have a theory that they may be the wrong way round in the game. Untested as of yet.

 

M247 is AT according to this:

 

http://en.wikipedia.org/wiki/Hydra_70

 

Almost no google hits on M5 at all.

Edited August 26, 2012 by marcos

[luza]

You do not. Mk-5 is HEAT and M151 is HE fragmentation.

 

mybad :D