1.65.1.118 ID:0053583 31/Jan/17 M48A1 Turret Face Armor Incorrect, Doesn't maintain 177.8mm LOS

[Conraire 5,721]

Vehicles Effected:

90mm Gun Tank M48A1 Patton III

 

The Issue:

Currently the armor model for the M48A1 does not match what is listed in historical sources.  Currently the majority of the Turret face is only 127mm thick, which does not maintain a Line of Sight/LoS thickness of 177.8-178mm or 7inches, as listed in most historical sources referring to this tank. 

 

The Solution:

Unfortunately the UI at present doesn't display lateral construction angle.  Which makes it difficult to predict how thick the armor should be past the initial square on sections that are around the gun shield.  Thankfully we do have the Chrysler casting diagram for the turret, to give us a basis of what the thickness should be. 

 

This is page 14 from the manual, TM 9-718B Aug 1952, 90mm Gun Tank T48 (designation of the M48/M48A1 before standardization based on cupolas)

As you can see it lists a thickness of 7inches for the turret front at 0degree's.  Interpreted literally many people including myself thought that meant 7inch actual thickness for the entire turret face.  That unfortunately is incorrect as well, which the Chrysler diagram displays quite well.  What it actually means is the turret front has a LoS thickness equal to 7inches across the entire turret face.

 

The same thing can be seen from Hunnicutt's Patton book, from the datasheets there.

Again many have misinterpreted this to mean actual thickness. 

 

Which brings us to the Chrysler Diagram for the turret front

This clearly displays what they really mean, that the turret front is designed with a 7inch LoS thickness basis.  And since in game I can use direct view of the armor, it gives a 5.5inch basis for 1R and 3L, and a 5inch basis for 2R and 4L.

          

 

Which gives us a picture like this, as to what the Turret armor of the M48A1 should look like.  Notice other than the direct turret face around the Gun shield, how close this actually comes to to what the M60 currently has.  This is based on trying to maintain a LoS thickness basis of 178mm across the turret face, while trying to take into account compound angles.  While also trying to follow the Chrysler casting diagram as closely as possible.  Unfortunately this is the best I can do, until some time in April or later when I can get my thickness gauge onto a real M48/M60 Turret, to measure the actual thickness's for sure. 

 

Ultimately it also depends on how complex you want to model the turret armor, as you could easily use a simplified version of this for the outer turret face area.

 

To Correct and list the area's, going by in game constructional angle display

 

Band 2R

LoS Thickness of 5in/127mm

Upper: 83.2mm @ 49 deg

Mid: 105mm @ 34deg

Lower: 119.4mm @ 20deg

 

Band 1R

LoS Thickness of 5.375in/136.5mm

Upper: 88.9mm @ 49deg

Mid: 115.8mm @ 32deg

Lower: 132.4mm @ 14deg

 

Band 3L

LoS Thickness of 5.5in/139.7mm

Upper: 91.5mm @ 49deg

Mid: 114.5mm @ 35deg

Lower: 135.5mm @ 14deg

 

Band 4L

LoS Thickness of 5in/127mm

Upper: 78.2mm @ 52deg

Mid: 100mm @ 38deg

Lower: 119.4 @ 20deg

 

And of course this is the diagram from Chrysler that the above cuts are taken from.

 

[KnightoftheAbyss 3,385]

Hi Conraire,

                   This is very close to the report ID:0048913.   Certainly is using the same references.

 

I will consult with the Developers and get back to you soon.

 

Thanks for the report.

 

Cheers

[Conraire 5,721]

18 minutes ago, KnightoftheAbyss said:

Hi Conraire,

                   This is very close to the report ID:0048913.   Certainly is using the same references.

 

I will consult with the Developers and get back to you soon.

 

Thanks for the report.

 

Cheers

 

Yeah, I already asked Smin about that one, and the other one.  They were both rejected by the devs for more or less the reason that while the sources list the 7inch thickness, they aren't 7inch actual thickness on the turret face, which is what the previous reports were asking for. 

 

Quote

It is necessary to take into account that at the Detroit tank arsenal casting blueprint drawing indicated given the thickness of armor, rather than the thickness of the normal, who are exposed to reserve areas in the game. 
The same applies to Hunnicutt, apparently, regarding the tower. He indicated 178mm inclination of 0 degrees with the forehead of the tower, while the tower armor practically everywhere has a slope of zero, so the thickness is reduced, but not normal thickness.

 

Both previous reports using these sources were more or less incorrect due to that.  None of the previous reports used the sources to determine actual Line of Sight thickness for the turret face though.  The Chrysler diagram when used previously was being translated into actual thickness instead of Line of Sight, which is clearly what it's showing.  I made the same error on that as well before.  But you'll notice due to going by line of sight for each section the some area's get stronger while others are weaker. 

 

But like I pointed out, this does put it very close to what the M60's turret is, sans the area right around the Gun shield, which according to the diagram should be thicker.  I may be using the same available sources, but, the suggested fix solution is different from what has been reported previously. Unfortunately these are the best sources I have until spring when I can get out and get the actual measurements.  I figured that though the data was there in previous reports, the approach at fixing things was wrong, which is why I can understand why those were rejected.

[KnightoftheAbyss 3,385]

Thanks for the further explanation.  I will seek further advice.

 

Cheers,

 

[Conraire 5,721]

On 1/28/2017 at 7:07 PM, Conraire said:

To Correct and list the area's, going by in game constructional angle display

 

Band 2R

LoS Thickness of 5in/127mm

Upper: 83.2mm @ 49 deg

Mid: 105mm @ 34deg

Lower: 119.4mm @ 20deg

 

Band 1R

LoS Thickness of 5.375in/136.5mm

Upper: 88.9mm @ 49deg

Mid: 115.8mm @ 32deg

Lower: 132.4mm @ 14deg

 

Band 3L

LoS Thickness of 5.5in/139.7mm

Upper: 91.5mm @ 49deg

Mid: 114.5mm @ 35deg

Lower: 135.5mm @ 14deg

 

Band 4L

LoS Thickness of 5in/127mm

Upper: 78.2mm @ 52deg

Mid: 100mm @ 38deg

Lower: 119.4 @ 20deg

 

I added this to the original post, since I'd previously forgotten to compensate for vertical construction angle on the lower segments of the bands.  I just need to update the picture to reflect that. 

[KnightoftheAbyss 3,385]

Thanks for that and for your effort on this issue.  It is very much appreciated.

 

Your information has been forwarded to the developers and the tracking number is: ID:0053583      

 

This thread will remain unlocked for one week (7 days) so that anyone with additional information\evidence\examples will have a place to post.  
After this time the report will remain active but will be archived.

 

It will also serve as a place where the developers will post questions for you to answer so please keep up to date here.

 

Cheers mate

 

 

 

[Conraire 5,721]

Been meaning to get to this earlier, but I've been busy with out of game stuff. Just a bit more fine detail on the direct turret face directly around the gun shield, Rather than just the flat 154mm at 30 deg.  Hunted down my protractor and did some angle measuring on the turret assembly diagram for the turret face.

 

 

 

[KnightoftheAbyss 3,385]

Thanks

[KnightoftheAbyss 3,385]

Archived