M1A2 Armor

[Guest jaja]

Most sources on the M1A2 give its armor at at least approxamatly 900mm at approxamatly 80 degrees for kinetic energy.

[Guest MajorH]

Please name those sources.

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Best regards, Major H

majorh@mac.com

[minmax]

Do those figures include Reactive Aromor and the thin aluminmum mounting plates?

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M. L. Johnson

TAOC DAWG

[Trooper]

Reactive armour?!

Can't say I've heard much over 600 myself. The problem with Jane's is that it just says "Classified." Cheaters.

NTM

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The difference between infantrymen and cavalrymen is that cavalrymen get to die faster, for we ride into battle!

[Allan Wotherspoon]

No reactive armour on the M1.

In terms of the effective armour thickness, in 20 or 30 years we may know for sure. 900mm may well be correct, or it may be less or more.

There's been considerable speculation on Tanknet.org with respect to the armour thicknesses of various tanks, the M1 included. Check out this URL for the most recent thread:

http://www.tanknet.org/ubb/Forum1/HTML/000080.html

Based on the speculation there, 900mm KE protection may not be unreasonable for the M1A2SEP.

Allan

[Guest jaja]

My sources include Steel Beasts for precise information, and books such as Company Team (I think that's what its called) by John F Antal (I think that's his name) for general information (they say the front is immune to any OPFOR current weapon). I used TankNet as well.

[Carter]

In published sources I've read that the composite armor of the M1A2 has 600mm of kinetic energy protection and 1300mm of chemical energy protection.

That is consistent with the AFJI (Armed Forces Journal International) estimates for the M-1A1HA listed on the tanknet.org site.

> Most sources on the M1A2 give its armor at

> least approximately 900mm at approximately

> 80 degrees for kinetic energy.

The glacis of the Abrams is sloped at 80 degrees. Off hand I'm estimating that an 80 degree slope would give a 156mm RHA sheet of armor the equivalent of 900mm of protection. Easily done, but that's only the glacis. The turret is another matter entirely.

Maybe the Abrams has more protection than is publicly known. Maybe the brand new M1A2 SEP has advanced composite DU armor. (The Russians must have some reason to want to go to a monster 152mm main gun when the 125 mm 3BM32 DU Penetrator is said to penetrate 680mm RHA at 2000m). But the M1A2 SEP isn't modeled in TacOps.

And I think it's best to go with established sources rather than internet speculation

I've also read that the Abrams _can_ mount reactive armor. I've never heard of this being done in practice. It already has a huge amount of chemical energy protection due to its composite armor. . . although the latest reactive armor could provide extra SABOT protection as well.

[This message has been edited by Carter (edited 02-02-2001).]

[Guest jaja]

The turret and hull have 80 degrees slope too (since the turret is double sloped).

[Carter]

80 degrees is near horizontal. Almost flat.

The glacis and underside of the turret are sloped close to 80 degrees, but the front facing appears to be more like 30 to 40 degrees.

Sloping multipliers are:

30 degrees = 1.155

40 degrees = 1.305

80 degrees = 5.759

A little bit of armor goes a long way at 80 degrees, but the turret armor needs to be much thicker.

[Guest jaja]

The armor on the turret is not only sloped toward the back of the tank. It is also sloped to the side (like sidal armor would be). John F. Antal confirms that the turret armor is also 80 degrees.

[Carter]

Thanks for pointing out the 2 axis slope, I hadn't thought of it, it should have been obvious to me. However . . .

A 40 degree pitch in two directions does not equal a single 80 degree slope.

40 degree double slope = 1.305 x 1.305 = 1.703

Which is still a lot less that the 5.759 multiplier for 80 degrees

I believe tanknet.org shows a similar calculation for the Abrams double slope using a more conservative 35 degrees by 40 degrees.

Note that this double slope value is only valid for a front turret centerline "head on" shot.

[This message has been edited by Carter (edited 02-05-2001).]

[This message has been edited by Carter (edited 02-05-2001).]

[Guest jaja]

Well, if that is the correct mathamatics, it seems strance to have such good armor on the hull and glacis and much poorer armor on the turret.

[Mike Robel]

Lets just say that the armor on the turret, while it doesn't have much of a slope, is REALLY thick. When my battalion got IP M1s, you could see the weld where the additional armor was welded.

No, I don't remember how much thicker, but it was really thick. I am not sure anyone on the forum really needs to know how thick, even if I did remember.

[Carter]

I asked my good friend Vladimir, and he gave a figure of approximately 600 mm thickness for the forward turret. (Sorry, had to tease a little bit)

The question is . . . How much RHAe does that composite armor thickness give?

There are several estimates on the tanknet.org link listed above. (Look for VanDerBob's giant post)

BTW I'd like to thank Mike Robel for writing his article about TacOps and BCT on strategypage.com. His article really got me interested in playing TacOps. I just hope he's not regretting it now.

[Mike Robel]

I like writing about wargames almost as much as I like playing them. Sadly, there are few wargames I like to play anymore, so writing has dried up a litte....

[Determinant]

Something that's always bothered me about the photos that I've seen of the Abrams (never seen one in the flesh): It always looks to have a bad shot trap under the main gun mantlet (cf Leopard2 and Challenger2). I note Carter's quote about under turret armour (but it can't be meant to deflect kinetic attacks onto the top deck or into the turret ring surely?) - it all leaves me v. confused.

[Guest jaja]

I think the shot trap on the Abrams (and more notably the Merkava) just deflects the shot to the hevily armored hull.

Here's my conservative estimate for M1A2 armor (and rounded signifagantly down after all calculations). When planning or estimating I always like to be conservative if possible for obvious reasons. If anyone can get exact thicknesses for the armor please do so. It will allow us to refine our estimates to a higher degree.

M1A2 glacis and hull:

100mm of armor at 80@ for 575mm equivalent thickness. This gives 850mm of kinetic and 1400mm of chemical protection.

Turret:

375mm of armor at 40@ by 35@ for 550mm equivalent thickness. This gives 825mm of kinetic and 1375mm chemical protection.

I use the ratio of 3mm of steel equel to 2mm of composite for kinetic energy protection. I use this ratio to account for depleted uranium, titanium, special steel alloy, etc.

I use the ratio of 5mm of steel equel to 2mm of composite for chemical energy protection. I use this ratio to account for ceramics, glass fiber, lamanation, etc., and the above factors.

The 600mm equivalent steel seems to be more appropiate for the origanal M1. That is the figure my books give for Western tanks of that era, and it seems to make sense when compared to the 300mm M60 figure. Why would the US build a completly new, heavier, more costly tank for only a small speed increase and a ~100mm equivalent armor increase?

If there are any specific problems with my estimate or reasoning please point them out.

jaja

[Mike Robel]

Your estimates are probably too conservative. The M1A1/A2 are probably pretty impervious to fire from anything on the front slope and many on the flanks. The only M1s killed in the Gulf were by other M1s.

[Allan Wotherspoon]

Originally posted by Determinant:

Something that's always bothered me about the photos that I've seen of the Abrams (never seen one in the flesh): It always looks to have a bad shot trap under the main gun mantlet (cf Leopard2 and Challenger2). I note Carter's quote about under turret armour (but it can't be meant to deflect kinetic attacks onto the top deck or into the turret ring surely?) - it all leaves me v. confused.

The shot trap on the M1 and other modern tanks is not as bad as it looks. Modern APFSDS rounds are designed not to richochet. Instead they turn inwards and dig into the armour. If they don't penetrate they tend to break up. Only at very shallow angles to they tend to ricochet. It is very unlikely that a round that hit that area would be deflected downwards into the hull.

Allan

[Guest jaja]

Originally posted by Mike Robel:

Your estimates are probably too conservative. The M1A1/A2 are probably pretty impervious to fire from anything on the front slope and many on the flanks. The only M1s killed in the Gulf were by other M1s.

Even with my conservative estimates the M1A2 is still impervious frontally to any weapon used by OPFOR. Even Steel Beasts, however, rates the M1A2 flank armor as not nearly as good as the front.