Official documents for real life armor values for 80s Abrams tanks are really inconsistent ...

[Bobjack1240]

Its a good thing the devs probably used the Steelbeasts '79  M1 Abrams armor values instead of using real life documents because I've looked at real life documents and using real life documents would have been inconsistent as hell.

 

This is especially true pertaining to their ke protection values. A British Army evaluation from 1982 ("Future Main Battle Tank from 1-3-82 to 3-28-83)  rated the '79 Abrams as "slightly less than the Challenger 1" in ke protection. If this is true, then the Abrams would be slightly less than 500mm vs ke. We know this wasn't an M1IP or M1A1 prototype because before those entered service (the IP entered service in '84 and the A1 entered service in '85), both of those carried the prototype designation M1E1. The vehicle in the British evaluation is just called M1 Abrams. 

 

Slightly less than 500 would also imply the '79 Abrams would have been tested to withstand West German DM-13 (penetrates 450mm at 1km) which was more powerful than the Soviet BM-22 we have in game.

 

A CIA document from 1982 ("PROPOSAL FOR INTERAGENCY INTELLIGENCE MEMORANDUM ON SOVIET ARMOR PROGRAM") rates one version of the Abrams as "400mm rha vs ke and 750mm rha vs heat".

 

Another CIA document from 1987 ("NEAR EAST AND SOUTH ASIA REVIEW") rates the M1A1 as 380mm ve ke attack and 900 vs heat. 

 

 

 

The firepower and armor protection results for the Future Main Battle Tank Evaluation

 

 

A British MOD brochure from around the same time (the very early 80s).

 

 

 

The 1982 CIA document

 

 

 

XM1 Vulnerability Analysis 1977

 

 

 

XM1 British Trial March-April 1978

 

Edited December 19, 2021 by Bobjack1240

[MikeyD]

When building the model for the M1 in the game the model maker had to slice off a considerable amount of frontal armor from the basic CMSF M1A1. Its telling that the Pentagon felt the need to significantly boost the armor of the turret front a couple years after Abrams was first fielded.

 

[Bobjack1240]

That's really interesting now that you bring that up. Didn't the Shock Force A1 also have depleted uranium or was it a Chobham M1A1 because if it was DU, they would have had to slice even more armor off?

 

Edited December 19, 2021 by Bobjack1240

[dbsapp]

31 minutes ago, Bobjack1240 said:

Its a good thing the devs probably used the Steelbeasts '79  M1 Abrams armor values instead of using real life documents because I've looked at real life documents and using real life documents would have been inconsistent as hell.

 

This is especially true pertaining to their ke protection values. A British Army evaluation from 1982 ("Future Main Battle Tank from 1-3-82 to 3-28-83)  rated the '79 Abrams as "slightly less than the Challenger 1" in ke protection. If this is true, then the Abrams would be slightly less than 500mm vs ke. We know this wasn't an M1IP or M1A1 prototype because before those entered service (the IP entered service in '84 and the A1 entered service in '85), both of those carried the prototype designation M1E1. The vehicle in the British evaluation is just called M1 Abrams. 

 

Slightly less than 500 would also imply the '79 Abrams would have been tested to withstand West German DM-13 (penetrates 450mm at 1km) which was more powerful than the Soviet BM-22 we have in game.

 

A CIA document from 1982 ("PROPOSAL FOR INTERAGENCY INTELLIGENCE MEMORANDUM ON SOVIET ARMOR PROGRAM") rates one version of the Abrams as "400mm rha vs ke and 750mm rha vs heat".

 

Another CIA document from 1987 ("NEAR EAST AND SOUTH ASIA REVIEW") rates the M1A1 as 380mm ve ke attack and 900 vs heat. 

 

 

 

The firepower and armor protection results for the Future Main Battle Tank Evaluation

 

 

A British MOD brochure from around the same time (the very early 80s).

 

 

 

The 1982 CIA document

 

 

 

XM1 Vulnerability Analysis 1977

 

 

 

XM1 British Trial March-April 1978

 

Thank you, a lot of interesting information.

Strange, that you call you findings "inconsistent". 380, 400 and less than 500 against KE sounds pretty coherent. Seems like the number is somewhere near 400, maybe slightly less.

M1 in Combat Mission is absolutely game breaking asset that literally overpowered boyond any reasonable simulation or realism standards. In CMCW early version of Abrams withstands RPG hit to the sides.

[The_Capt]

1 hour ago, dbsapp said:

Strange, that you call you findings "inconsistent". 380, 400 and less than 500 against KE sounds pretty coherent. Seems like the number is somewhere near 400, maybe slightly less.

M1 in Combat Mission is absolutely game breaking asset that literally overpowered boyond any reasonable simulation or realism standards. In CMCW early version of Abrams withstands RPG hit to the sides.

Sigh, oh how I have missed this.  No, it is not an "absolutely game breaking asset" [aside: when did this become a thing?  Back in the day, if a game was hard you found a way to beat it, not run to social media and declare it "broken!! OMG...END OF DAYZ!!"  Whatever.].  So if the M1 105mm version is rolling with about 400 KE then the BM 22 which has penetration at point blank range of 440mm (http://www.steelbeasts.com/sbwiki/index.php?title=3BM22) is going to be challenged at range to penetrate the M1 frontally.

What is interesting is that the US appears to be more afraid of HEAT than KE, which given all the Soviet ATGMs makes sense. 

 

[chuckdyke]

Yom Kippur War introduced the world to the Sagger (Media) and the M60 and Centurion became obsolete overnight. Yes HEAT ruled for a while. So they needed a better tank. Good thing they made one, it makes a good topic on social media which didn't exist at the time. 

 

Edited December 20, 2021 by chuckdyke

[Codreanu]

3 hours ago, dbsapp said:

M1 in Combat Mission is absolutely game breaking asset that literally overpowered boyond any reasonable simulation or realism standards.

Good thing seeing them at all in CMCW is awfully rare, massed 125mm fire even from the front will severely degrade it's spotting ability and will easily punch through the mantlet if it can hit it and take out the gun too.

1 hour ago, The_Capt said:

So if the M1 105mm version is rolling with about 400 KE then the BM 22 which has penetration at point blank range of 440mm

Are those the actual in game stats of them though? Haven't tested it exhaustively but in the one scenario that pits the T-80 versus the Abrams, 3BM22 didn't seem to want to penetrate the Abrams frontally, but angle could have been a factor to that, generally not a big deal though because like I said to db, massed fire and a hit to the mantlet deals with them just fine.

[MikeyD]

The problem with attempting to assess 'special armor' is we don't have the clearest picture of what exactly we're talking about. Oftentimes penetration estimates are exactly that - estimated. Numbers plugged into an algorithm. I've seen multiple cutaway drawings of Abrams side armor on the web but none of them looked like this (see below). 

[Artkin]

1 hour ago, Codreanu said:

Good thing seeing them at all in CMCW is awfully rare, massed 125mm fire even from the front will severely degrade it's spotting ability and will easily punch through the mantlet if it can hit it and take out the gun too.

Are those the actual in game stats of them though? Haven't tested it exhaustively but in the one scenario that pits the T-80 versus the Abrams, 3BM22 didn't seem to want to penetrate the Abrams frontally, but angle could have been a factor to that, generally not a big deal though because like I said to db, massed fire and a hit to the mantlet deals with them just fine.

Ive had a T-64B penetrate an Abrams turret at ~250m

[The_Capt]

12 hours ago, Codreanu said:

Good thing seeing them at all in CMCW is awfully rare, massed 125mm fire even from the front will severely degrade it's spotting ability and will easily punch through the mantlet if it can hit it and take out the gun too.

Are those the actual in game stats of them though? Haven't tested it exhaustively but in the one scenario that pits the T-80 versus the Abrams, 3BM22 didn't seem to want to penetrate the Abrams frontally, but angle could have been a factor to that, generally not a big deal though because like I said to db, massed fire and a hit to the mantlet deals with them just fine.

We don’t know what the actual stats are for in game, BFC keeps that pretty close hold.  I have run a few tests and am seeing T80s able to penetrate and KO the M1 in the front turret at 500m with BM22, so I do not think based on what we have been able to glean that the in-game M1 frontal armour is too far off the 400mm KE.  

[Bobjack1240]

And we don't actually know if the 400 number is correct. Here's the 1987 CIA document about the M1A1 which had better ke protection.

Edited December 20, 2021 by Bobjack1240

[Bobjack1240]

Intelligence documents can be very inconsistent because the other document from 1982 was probably meant to be interpreted as the Abrams '79 as that was the only variant in service at the time.

 

Edited December 20, 2021 by Bobjack1240

[Bobjack1240]

Because of this, for an official "cannon answer" I would go with official army evaluations. In this case, I would have gone with the British 1982 evaluation and compensated by equipping the T-80s with BM-26.

BM-26 entered service in 1982 (so it would have technically been within the game's time period) and would have had similar performance to the American M833 which wouldn't come out until 1983, and isn't within the game's time period. Nothing in service at the time would have been safe from BM-26.

Edited December 20, 2021 by Bobjack1240

[FinStabilized]

The consistency of the documents can't be determined just by comparing the raw numbers. There are a ton of factors at play.

-US protection values are frequently at an angle but it might not be cited in some documents. This happens all the time.

-Hull protection is not consistent, the fuel tanks add to it on the outer 3rd.

-Hull protection varys by threat, and I don't mean heat vs ke. Abrams armor value vs 115mm rounds will be different than 125mm rounds. There will even be differences within caliber due to differences in ammo design. There can be huge variances here, especially since Abrams hull armor is NERA. Equivalency to RHA is only a semi-valid estimate. It will be more consistent in some cases than others.

 

[Amedeo]

On 12/20/2021 at 2:36 AM, Artkin said:

Ive had a T-64B penetrate an Abrams turret at ~250m

It's not uncommon to obtain frontal penetration against an Abrams with 3BM22 armed tanks even at 2000m range in CMCW. And T-80B/T-64B tanks are kinda able to shrug off most M774 hits at that distance; the problem is that the M1 will likely obtain a "lower hull hit" after a couple tries, and no Soviet tank is likely to survive such an hit.

[BeondTheGrave]

On 12/20/2021 at 5:14 PM, FinStabilized said:

The consistency of the documents can't be determined just by comparing the raw numbers. There are a ton of factors at play.

-US protection values are frequently at an angle but it might not be cited in some documents. This happens all the time.

-Hull protection is not consistent, the fuel tanks add to it on the outer 3rd.

-Hull protection varys by threat, and I don't mean heat vs ke. Abrams armor value vs 115mm rounds will be different than 125mm rounds. There will even be differences within caliber due to differences in ammo design. There can be huge variances here, especially since Abrams hull armor is NERA. Equivalency to RHA is only a semi-valid estimate. It will be more consistent in some cases than others.

 

Also working against the consistency of documents is that theyre spread across multiple US and non-US agencies. It needs to be stressed that the CIA is not the Army, they dont do Army stuff, and they dont really care about Army stuff. One might as well ask the Air Force or the Navy what they think about the Abrams armor layout is. This is especially important because classified information like this would certainly be compartmentalized. Versions of reports and documentation shared outside of the Project and its direct chain of command would have to be sanitized of any information the Army didn't want to share or didn't want let out into the wild. Protection data would be one such example. British MoD docs would again be written from even cleaner reports and vauger estimates, when the Army stamps something NONFORN they mean it. What data the Brits got, how they could use it, what they could publish with it, and most importantly for us what the procedure for storing and releasing that data would all be controlled by a framework agreement between the two countries. For example the Kennedy era information sharing framework set up for the MBT-70 and other early 60s dev projects soldiered on into the 1970s. Not sure if it was replaced in the 1980s, but I dont think it was. Meanwhile the framework for sharing with the Israeli government was very limited and controlled meaning exchanges often had to be 'informal' in nature. Regardless the data that we have access to from the MoD may not be the be all end all and have to be considered in a limited, contextual way. 

I would suspect that there really arn't any docs that dish on the M1s tested armor protection or about the tank's actual armor layout. If you wanted to get the authoritative set of docs you'd need to check the XM1 program files which IIRC are at the National Archives in DC. Last I checked though, those detailed project files were still classified for the MBT-70 program. Probably these days you could get some of the overall planning documents, but the technical data was likely marked SECRET or higher. Meaning were probably on the 60 year declassification track for some of this juicy stuff, and then only if the M1 is replaced by then or the armored layout has fundamentally changed since the XM1 days.