M1 Series tanks 3D Model incorrect

[TheRealSteve]

Hello.

It’s been about 8 months since I created the bug report regarding the turret ring model of the M1 tanks. The report was acknowledged, and forwarded to the developers as a suggestion.

You can find my bug report here:
https://community.gaijin.net/issues/p/warthunder/i/hn6WHPVB7r3K

Additionally, some other major Abrams damage model discrepancies were addressed in additional bug reports (not made by me) in regards to the frontal fuel cell bulkhead model and thicknesses. One individual that made a report on this actually posted a picture inside the hull of an M1 as proof, which can no longer be seen by a viewer since the report is closed. The corrected fuel cell bulkheads would offer much greater frontal hull protection than what we currently see in game.

Those bug reports can be found here:
https://community.gaijin.net/issues/p/warthunder/i/xK4GPBS59dUL
https://community.gaijin.net/issues/p/warthunder/i/Y2HnjTv8kNAG

Currently in game, an impact to the lower hull to the left or to the right of the driver would look like this: 32mm RHA → 360mm NERA → 101mm RHA → Fuel → 19mm RHA.

-and an impact to the upper front plate to the left or right of the driver currently looks like this:
38.1mm RHA at 82* → fuel → 19mm RHA.

Adjusted for the correct fuel cell bulkheads, a penetration to the lower hull to the left or right of the driver would look like this:
32mm RHA → 360mm NERA → 101mm RHA → 25.4mm → fuel → 25.4mm.
Approximately a 10% increase in protection.

-and an impact to the upper front plate to the left or right of the driver would then look like this:
38.1mm RHA at 82* → 25.4mm RHA at 82* → fuel → 25.4mm RHA.
When considering the LOS calculated thicknesses of the angled plates, this offers a WHOPPING approx. 40% INCREASE in protection for the left and right thirds of the UFP.

This, in combination with a correctly modeled turret ring, would offer a HUGE INCREASE in frontal area protection for the M1 series of vehicles… about half of its entire frontal surface area.

I created this thread hoping to raise awareness to this, discuss the significance that these changes may bring, and perhaps remind Gaijin of the issue.

If you see this, please go ahead and click on the links above and hit the “I have the same issue!” button to remind them that these are issues the player base still cares about and would like resolved as soon as possible.

And if any moderators see this, please out of respect of the time I put into my research just TELL ME if they’re working on it or not XD!!!

[BasherBenDawg8]

Well done on your research and kudos to you for putting all this time and effort into it. Hopefully they actually do something about this as it’s quite frustrating how much they ignore and seemingly forget about bug reports… (some go for years without changes or anything done, fingers crossed this won’t be the case for these)

[TheRealSteve]

Thank you! Although I am an Abrams enjoying American and may have some bias in me, I just want vehicles to be fairly and accurately modeled from the information that we have available to us in certainty, since Gaijin expressed no interest in buffing the lower front plate, this is an alternate solution…

And to be honest with you, I think I’d rather have these issues fixed than have a DU hull.

[SPANISH_AVENGER]

I really hope this is corrected and implemented ASAFP.

The improved hull composite for SEPv2 and AIM is a lost cause… so at least these matters could significantly improve the Abrams without having to resort to classified matters.

And these improvements would make the tank WAY better than many people would realise.

The fuel tank areas would become stronger.
The turret ring would no longer be vulnerable to autocanons.
The turret ring would also protect significantly better against (unrealistically) UFP bouncing APFSDS shells.

[TheRealSteve]

Thank you for pointing that out. It is important for people that are just seeing this to understand that the improve turret ring will not reliably protect the vehicle from high caliber APFSDS shells, though it may make it more likely to have an unlucky shatter here and there.

What is important about the turret ring is to protect the vehicle from small caliber cannons from IFVs and SPAAs. This would be an AMAZING buff!

And yes, shells that have bounced off the upper front plate shouldn’t have enough momentum (or the proper angle) to penetrate this improved turret ring as well.

Thanks for the support

[Caernarvon02]

With how poorly done challenger is done I cant give you more than a well done on your research

[SPANISH_AVENGER]

@TheRealSteve

What is important about the turret ring is to protect the vehicle from small caliber cannons from IFVs and SPAAs. This would be an AMAZING buff!

Indeed. Being frontally killed by BMPs, PUMAs, Gepards and Chunguskas is so… anti-climatic.

With the fix on the other hand, the ring would be able to withstand even 2S38s!

@TheRealSteve

Thanks for the support

Thank you for making these great reports! Every step taken to make the WT Abrams tanks as great as their real life counterparts counts.

It’s sad to see how the WT iterations are artificially relegated to being barely “average” because of issues like these.

o7

[Константинович7]

@BasherBenDawg8

Hopefully they actually do something about this

[RemoveCASfromGRB]

@TheRealSteve

-and an impact to the upper front plate to the left or right of the driver would then look like this:
38.1mm RHA at 82* → 25.4mm RHA at 82* → fuel → 25.4mm RHA.
When considering the LOS calculated thicknesses of the angled plates, this offers a WHOPPING approx. 40% INCREASE in protection for the left and right thirds of the UFP.

38.1mm x 1.0(RHA) / cos(82°) → 25.4mm x 1.0(RHA) / cos(82°) → Fuel → 25.4mm

38.1mm / 0.139 → 25.4mm / 0.139 → Fuel → 25.4mm

274.1mm → 182.73mm → Fuel → 25.4mm

Total Effective thickness: 482.23mm L/R UFP

[TheRealSteve]

Sorry, are you correcting me or just adding on?

Those numbers sound familiar to what I did, though I don’t think I want to go through that again.

It’s also important to note that these are general estimates since the impact angles may have slight inconsistencies and I also do not know what the effective thickness of the fuel is.

[RemoveCASfromGRB]

Adding on.

You don’t show the calculation in your post. People will not believe in that 40% increase without showing your work

;)

[TheRealSteve]

Yes you’re right, thank you.

[STGN]

You made a few mistakes here.

First, the Angle of the UFP is 83 degrees not 82. This is clear from drawings:

And more importantly its gives the 1.5" UFP a LOS thickness of 312mm which is very close to the protection requirement of 322 mm when the hull was redesigned from in 1975(frontal protection on Chobham armor part was likely increased to 370-380 for production). LOS of 1,5" @ 82deg is only 273mm, way below requirement.

Second, the fuel tanks bulkheads only have significant additional protection on top

The sides and rear of the bulkheads appears to only be .25" max or 6.35mm or less. We can see that the welds indicate only thick plate on top and that plate appears to be 1.5" aswell for a total of 3" protection over the fuel tanks:

Which again corresponds well with protection requirements against CE, LOS of 3" @ 83degrees is 625mm, close to the 636mm requirement.
So, the UFP is currently underperforming considerably in WT, but the Chobham armor part is pretty close. The fuel bulkhead is not 1" on all sides, they are thin except for the top and provides only ~0.25" of additional steel protection and probably only towards the crew compartment not towards the front and exterior sides. The fuel tanks themselves are again ~.25 thick and are made of Lexan so not a whole lot of protection.

Third, the turret ring is made from cast steel not RHA

I have just made a Issue report: M1 Abrams tanks turret ring and sight roof plate wrong material. // Gaijin.net // Issues

[BasherBenDawg8]

So the UFP angle could be even more extreme? Heck yeah! When gaijoobles!

[Well_iJosh]

It’s already 83 degrees in game :)

[CodeNameColdWar]

So any source about fuel tank bulkheads thickness ? other than photos ?
Gaijin surely need more than photos and word.

In his bugreport it clearly state “steel bulkheads 25.4mm” in document.
Good source on changing RHA to CHA though

[STGN]

No, I don’t have a source for bulkhead thickness other than the photo, but it clearly disproves the 1" thick bulkhead text. Sometimes even government documents have bad info in them, if you research a lot like I have done you start seeing it happen rather often. But Gaijin will do what they think serves the game best anyway they will pick and choose if they believe sources on a whim anyway. Like I used secondary sources and images showing that the M247 can’t depress to -10 only -5 contrary to what some manuals say it can. And gaijin was like, it’s on paper, shut up. The same manual said the gun could depress to -3 over the hull which I then bug reported using the manual and a picture and then Gaijin said, it can’t shoot through the hull it has to be 0-degree depression over hull, shut up. So, there is a large degree of arbitrariness in whether a source will be followed or not anyway.

[CodeNameColdWar]

It is what it is. iirc as they said that they couldn’t just adjust that from picture alone. They would need at least measurement to be present in the picture. Else they would have to measure bulkhead thickness themself. If they ever get the change. (like they did measure M1 Abrams armor at the museum)
So document will have to do for now. At least that document are official.

[STGN]

Well, I am more of a LARPer so I don’t think they should add 1" of armor which is clearly not there and especially not twice (exterior plate where the armor hull allready exists), the MK1 eyeball is a better source than any document.
When I meet a discrepancy between what I am seeing and what I am reading I start thinking what could be the reason for the discrepancy?
Here are a few possiblilities:

1. The text might just be misleading because the Abrams does indeed have 2 fuel tanks behind a 1" bulkhead, namely the 2 engine tanks, which sits behind a 1" bulkhead protecting the driver, as these tanks are in the engine compartment they are not protected by the main armor like the frontal fuel tanks.

2. Its old information that never got corrected which made its way into the design handbook. If you look at this drawing of an early Abrams interior:
   
   It is indeed drawn as having realitvely thick plates next to the driver, and it is no secred that the Chrysler had initally planed to use the fuel system as armor for the original 1974 model, here is the concept Chrysler first sugested in 1972:
   

   
   and here is the prototype hull:
   
   Notice the thick front UFP plate, not alot of room for Chobham and is instead used for fuel to cover so having the fuel tanks as extra amor was nessesary.
   Here we have the drivers compartment of the prototype notice the lack of complex shapes, likely because it has thicker fuel bulkheads.
   
   

However as the XM1 armor matured was focused towards the front going from 320mm to 370-380mm KE protection so why not take the weight used for fuel tank bulkheads and put it in the front amor instead and you have more volume for fuel aswell?

Of cause both are speculation as to what happened and why the text is that way when photos show that the steel actually used in production vehicles was quite thin:

Look at all those curves on the right and a very thin weld line which means this is thin steel again probably max .25".

[CodeNameColdWar]

Again as i said before. Without proper document or source It would be inappropriate to adjust them from just the picture or eyeballing.
That leave us with what we got. Unless you or Gaijin can go and measure bulkhead thickness and take a picture.
That way Gaijin could adjust them more accurately. Or maybe there are declassified doc that contain this information that we haven’t found yet.