Sherman 75mm Effectiveness

[rexford]

One of the interesting aspects of German armor is that many tanks have face-hardened armor and some are limited to homogeneous armor, so one penetration figure does not cover both types.

Sherman 75mm APCBC penetrates 81mm homogeneous and 95mm face-hardened at 500m, based on TM9-1907.

PzKpfw IVH has face-hardened 85mm front hull, Tiger has 82mm homogeneous side armor.

Panther has 40mm face-hardened side hull on A and D models, StuG III probably has 30mm homogeneous side armor while PzKpfw IVH has 30mm face-hardened.

Tiger II with early turret has 100mm face-hardened mantlet and one side of turret is face-hardened, Tiger I is completely homogeneous armor.

This issue will come up big time in CM2, since PzKpfw III and IV use lots of face-hardened armor (most of the front armor), and Panther D not only has face-hardened side hull armor but the first 850 Panthers have face-hardened glacis plates. And Russian data for face-hardened penetration does not appear to be obtainable, based on our searches.

Russian ammo did not use armor piercing caps, so it would be less effective against face-hardened armor. The theory is that the Germans viewed Russia as the major threat, so armored their vehicles to defeat rounds without armor piercing caps.

Face-hardened armor would also be good in North Africa where the British didn't recognize that armor was in use until way into 1942. But Allied use of armor piercing caps left face-hardened armor in a weaker position relative to homogeneous armor.

As much as I hate to admit it, putting face-hardened armor on PzKpfw IVH front hull made the darn thing even more vulnerable to Sherman 75mm hits in France and Germany, and Panther side hull on A and D models is easier to beat with those low velocity Sherman hits due to the armor used.

[Iron Duke]

Rexford,

do you have any figures on the 37mm gun vs Face hardened and homogenous? Just curious because I am sure everyone here has played a QB where a Greyhound KO'd an Uber tank of some sort. Was there ever any "HVAP" ammo made for the 37mm? Was the gun any different on the Stuart as compared to the M8?

You da man rexford.

And when can I expect to buy your book?

[PzKpfw 1]

<BLOCKQUOTE>quote:</font><HR>Originally posted by rexford:

As much as I hate to admit it, putting face-hardened armor on PzKpfw IVH front hull made the darn thing even more vulnerable to Sherman 75mm hits in France and Germany, and Panther side hull on A and D models is easier to beat with those low velocity Sherman hits due to the armor used.<HR></BLOCKQUOTE>

An interesting AA report:

On the morning of 20 November 1944 I was tank commander of a Sherman medium tank mounting a 76mm gun. The Germans staged a counter-attack with infantry supported by at least 3 Mark V tanks.

Ordering my gunner to fire at the closest tank, which was aproximently, 800 yards away, he placed one right in the side, which was completely visible to me. To my amazement and disgust, I watched the shell bounce off the side.

My gunner fired at least six more rounds at the vehichle hitting it from the turret to the track. I was completely suprised to see it moveing after recieving 7 hits from my gun.

Sgt. F.W. Baker, 2nd Armored Div.

So either the above was an Ausf.G or the rounds just failed vs the side armor completely.

Regards, John Waters

[ 07-03-2001: Message edited by: PzKpfw 1 ]

[PzKpfw 1]

<BLOCKQUOTE>quote:</font><HR>Originally posted by rexford:

PzKpfw IVH has face-hardened 85mm front hull, Tiger has 82mm homogeneous side armor.

<HR></BLOCKQUOTE>

Lorrin where are you getting the 85mm thickness on the PzKpfw IV? Jentz, Zaloga, & Speilberger all put the hull front at 80mm as does CM. I also noticed you had the Tiger II TF at 189mm in another post yet Jentz etc, puts it at 180mm.

Regards, John Waters

[ 07-03-2001: Message edited by: PzKpfw 1 ]

[Blenheim]

You guys are crazy grogs !!! Totally crazy !!!

BUMP. Keep posting. (I love these threads... )

[Iron Duke]

**Bump**

[Vanir Ausf B]

<BLOCKQUOTE>quote:</font><HR>Originally posted by PzKpfw 1:

An interesting AA report:...

(snip)

<HR></BLOCKQUOTE>

I can't help but wonder if those rounds were hitting the side at a oblique angle. 76mm vs. Panther side at 800m should be no contest if the shot is perpendicular to the target.

[Jeff Duquette]

Aberdeen Proving Ground testing of 37mm vs. homogeneous and FH armor is laid out in TM9-1907. AP as well as APC rounds. I know Rexford has a copy of this because he references this Tech manual all the time.

[Dan Robertson]

<BLOCKQUOTE>quote:</font><HR>Originally posted by PzKpfw 1:

I also noticed you had the Tiger II TF at 189mm in another post yet Jentz etc, puts it at 180mm.

Regards, John Waters

<HR></BLOCKQUOTE>

He was talking about the original tiger II turret which was less well aroured on the front but the sides took up more of the frontal protection in this case.

[Jeff Duquette]

<BLOCKQUOTE>quote:</font><HR>John Said: Lorrin where are you getting the 85mm thickness on the PzKpfw IV? Jentz, Zaloga, & Speilberger all put the hull front at 80mm as does CM. I also noticed you had the Tiger II TF at 189mm in another post yet Jentz etc, puts it at 180mm.<HR></BLOCKQUOTE>

Didn’t the Germans have manufacturing specs\tolerances indicating plate thickness shell not be less than X millimeters and shell not exceed X millimeters. So manufacturing tolerance of MkIVF drivers front plate is listed as 50mm is FmvonSenger, yet a Watertown Arsenal report on a captured MkIVF indicates drivers plate thickness was 52mm. Infact just about all the plates of the captured MkIVF subjected to test measurements in the Watertown Report exceed minimal tolerance.

[Jeff Duquette]

John: You see same tolerance exceedence for plate thicknesses indicated in a report by British Army on test firing against a captured Tiger I hull in Tunisia. Report No. M6816A/4 No.1 dated 30 Oct 1943. See Jentz pg 15 "Tiger I & II Combat Tactics"

[Username]

The Panzer IV had spaced armor. Could the outer 30mm knock off the cap/disrupt the shell so that the inside 50mm would defeat the round?

The germans kept making Panzer IVs this way the whole war didnt they? Why not just move to an 80mm solid plate?

Inquiring minds want to know..

Lewis

[PzKpfw 1]

<BLOCKQUOTE>quote:</font><HR>Originally posted by Dan Robertson:

He was talking about the original tiger II turret which was less well aroured on the front but the sides took up more of the frontal protection in this case.<HR></BLOCKQUOTE>

No Dan the Tiger II 189mm refrence is from another thread, this thread concerns the Porshe turret thickness. I put in here to save myself a post a post .

Regards, John Waters

[PzKpfw 1]

<BLOCKQUOTE>quote:</font><HR>Originally posted by Username:

The germans kept making Panzer IVs this way the whole war didnt they? Why not just move to an 80mm solid plate?

Inquiring minds want to know..

Lewis[/QB]<HR></BLOCKQUOTE>

They did Lewis the Ausf,H & J used a single 80mm plate.

Regards, John Waters

[PzKpfw 1]

<BLOCKQUOTE>quote:</font><HR>Originally posted by Jeff Duquette:

John: You see same tolerance exceedence for plate thicknesses indicated in a report by British Army on test firing against a captured Tiger I hull in Tunisia. Report No. M6816A/4 No.1 dated 30 Oct 1943. See Jentz pg 15 "Tiger I & II Combat Tactics"<HR></BLOCKQUOTE>

Yes Jeff that wasn't my point the Tiger E's side armor was 80mm @ 0^, the Brit's have it as an 82mm rateing during their tests. The refrences list the PzKpfw IV H front hull as 80mm, & the Tiger II TF as 180mm @ 10^.

The reason I was curious as according to Lorrin the thickness's should be 85mm & 189mm. Which means both tanks in CM are incorrect in their plate thickness & resistance.

On a side note I just took out a Tiger II with an Firefly APCBC round at 1,180m with a turret front penetration.

Regards, John Waters

[Jeff Duquette]

<BLOCKQUOTE>quote:</font><HR>John Said: On a side note I just took out a Tiger II with an Firefly APCBC round at 1,180m with a turret front penetration. <HR></BLOCKQUOTE>

Nice shootin’ Tex :eek:

I had a Tiger I get a tunnel punched through its mantlet by a Stuart once. Had to replay the turn 5 times to make sure my eyes weren’t deceiving me. Sergeant Jeb Stuart and the Haunted Tank?

[rexford]

PzKpfw IVG had 30mm on top of 50mm, both face-hardened. Only the PzKpfw III carried spaced armor.

IVH had 80mm design thickness but German armor tended to be oversize, Panther glacis measures 85mm most of time, Tiger side armor is usually a few mm over 80mm, many British analyses use 85mm for IVH front.

Panther nose is 60mm design, British measurements put it at 65 to 75mm. Isigny test report on Mycenius site included an actual Panther nose armor measurement, it was 67mm.

189 for Tiger II turret front includes angle, 185mm at 10° slope equals 189 at 0° against 90mm APBC.

We use 85mm for Panther glacis and PzKpfw IVH front hull areas (driver plate and upper nose). 82mm for Tiger side and 102mm for Tiger front.

Our book has a discussion of armor design specs versus what was actually measured, which includes measurements by Robert Livingston at Aberdeen Proving Grounds and other locations. Robert also measured angles, and we have a neat drawing of the M4A1 upper hull front with a detailed layout of angles and thicknesses. He found an M4A1 at a Legion Post on his way back from Pennsylvania, and stopped to measure angles.

M4A1 upper hull front was one piece cast, which was 13% less resistance than rolled armor when 2" thickness hit by 75mm rounds. And American cast armor built prior to late 1943 tended to be flawed, so cut the resistance some more.

And M4A1 is less than 56° that you find on rolled armor glacis Shermans, so decrease resistance some more.

And M4A1 has those big driver and MG hoods at low angles.

Zaloga wrote in one of his books that American tankers refused to use M4A1 when rolled glacis Shermans were available. Is it any wonder?

The advantage of the M4A1 hull front is that the outside areas are sloped vertically and to the side, so hit the outside areas and ricochets will probably occur due to effective resistance.

We looked at 76mm hits bouncing off Panther side armor many times. The comment about angled hits is on the mark.

Armor is sloped at 40° vertically and say it is hit with side angle of 55° (35° from front hull facing). The resultant angle is 64° and armor resists like 120mm at vertical.

76mm APCBC penetration at 800 yards is 112mm, so rounds could all bounce off.

37mm APCBC penetration against face-hardened and homogeneous follows:

100m

78mm homogeneous, 73mm face-hardened

500m

69mm homogeneous, 67mm face-hardened

1000m

59mm homogeneous, 57mm face-hardened

There is British data which shows that 6 pounder APCBC shatter failed against face-hardened armor that is should have been able to penetrate. The larger difference between 37mm APCBC penetration against face-hardened and homogeneous at 100m could be due to nose failure at higher velocities.

[Username]

<BLOCKQUOTE>quote:</font><HR>Originally posted by PzKpfw 1:

They did Lewis the Ausf,H & J used a single 80mm plate.

Regards, John Waters<HR></BLOCKQUOTE>

So the omly Panzer IV with the spaced plate was a G? I imagine earlier F's could have been upgraded also.

Perhaps the tracks could perform this function also. The tracks were hardened steel.

Lewis

[rexford]

PzKpfw IVH generally used one single plate of about 85mm thickness. PzKfw IVG started out at 50mm front and later added 30mm bolted or welded to 50mm. I am not sure about the bolting cause most pictures seemed to show welds, but it has been a long time since I looked.

When two face-hardened plates are bolted or welded together, the total may be more resistance than the sum of the thicknesses.

When PzKpfw IIIH put 32mm face-hardened on top of 30mm face-hardened, the resultant resistance of the two plates was 69mm of face-hardened armor prior to slope effects.

This result is based on analysis of firing tests in North Africa using 37mm, 40mm, 57mm and 75mm ammunition (AP and APCBC).

The usual assumption is that two plates bolted or welded together are less resistance than a single plate with same thickness, many British test results show layered armor can be more resistant.

This is in our book along with spaced armor and edge effects.

[rexford]

Several posters on other sites have speculated that German armor was oversize so it would pass inspection. If the tank armor was a few millimeters short the whole output might be rejected, so make it a few mm too thick on average and make sure it passes.

A StuH welded mantlet that was supposed to be 50mm thick actually measured out at 65mm!

Robert Livingston measured several SU 100 glacis plates that were supposed to be 75mm thick, and they were all less than 75mm and some were under 70mm.

We used figures that were accepted in many sources. Russians, Americans, British all use 85mm for Panther glacis calculations during many, if not most, of their analysis. And 65mm for Panther nose.

Germans said 80mm and 60mm for Panther front hull, most penetration studies use 85 and 65.

[Andrew H.]

<BLOCKQUOTE>quote:</font><HR>Originally posted by rexford:

37mm APCBC penetration against face-hardened and homogeneous follows:

100m

78mm homogeneous, 73mm face-hardened

500m

69mm homogeneous, 67mm face-hardened

1000m

59mm homogeneous, 57mm face-hardened

<HR></BLOCKQUOTE>

There's a brief account in MacDonald's "A Time for Trumpets" of a Stuart driving out of some woods toward a road (presumably to avoid encirclement), encountering a Panther, and knocking it out with a short range side shot.

Which is not really a surprise to CM players (actually, the surprise is that it didn't happen more often), but it's nice to know that some improbable things that are theoretically possible actually occurred.

[Jeff Duquette]

Andrew...whats page number for this account. I only read about 1/2 the book (not that its not a good read).

[PzKpfw 1]

<BLOCKQUOTE>quote:</font><HR>Originally posted by rexford:

We used figures that were accepted in many sources. Russians, Americans, British all use 85mm for Panther glacis calculations during many, if not most, of their analysis. And 65mm for Panther nose.

Germans said 80mm and 60mm for Panther front hull, most penetration studies use 85 and 65.<HR></BLOCKQUOTE>

Yes Lorrin but why doesn't Jentz etc use these xtra mms in their works?, it also makes me wonder why ppl like Doyle, & Jentz etc,who have crawled over every German tank left from WW2, missed the xtra mm thickness on the plates & went with the official 80mm etc.

It also affects CM as CM models 80mm on both the PzKpfw IV H, J front hulls & Panther glacis, which by your findings are missing 5mms of armor. Unless you mean the Hull front's & glacis was 85mm @ 0^ as you meant with te Tiger II turret front.

Regards, John Waters

[ 07-03-2001: Message edited by: PzKpfw 1 ]

[PzKpfw 1]

<BLOCKQUOTE>quote:</font><HR>Originally posted by Jeff Duquette:

Nice shootin’ Tex :eek:

I had a Tiger I get a tunnel punched through its mantlet by a Stuart once. Had to replay the turn 5 times to make sure my eyes weren’t deceiving me. Sergeant Jeb Stuart and the Haunted Tank?<HR></BLOCKQUOTE>

ROFL I used to have a buncha those comics.

I thought my Firefly was dead, as I let the 2 dual it out stationary head to head the Vet Tiger II crew missed like 11 times, the Firefly killed it on the 6th shot. I re watched it 4 times ....

Regards, John Waters

[ 07-03-2001: Message edited by: PzKpfw 1 ]

[rexford]

85mm thick plates on Panther glacis and PzKpfw IVH front hull. 65mm thick plate on Panther nose, sometimes up to 75mm.

We don't know what others found or used, but we went through firing test data, what was actually measured by others or Livingston, and what Russia, Britain and U.S. used in their calculations.

We saw a trend towards more than 80mm thickness on Panther glacis plate and more than 60mm thickness on Panther nose plate, and it seemed that most studies assumed the greater thickness.

Just about every Russian analysis of Panther armor on The Russian Battlefield says 85mm thickness Panther glacis. Look through John Salt site for the many analyses of penetration ranges against Panther glacis armor, how many assume 80mm armor thickness? Very few use 80mm.

Since 85mm at 55° resists penetration like a much thicker vertical plate due to slope effects, when I refer to 85mm Panther glacis it is plate thickness.

Tiger II example was just a shortcut that I neglected to explain. The book lays out all the assumptions and math so readers won't be confused.