"Sicily - Sherman vs PzIVg/h Armor" Topic

I'm doing some work on mid-1943 comparisons between Shermans (UK and US) vs PzIVs (for late-g and early-h variants).

I have good info on the relative performance of the guns, but most of the info I have on performance comparison comes from data compiled at Normandy. So in terms of an overall Armor rating, I am undecided whether to rate the Sherman slightly higher than a PzIVg/h.

So in terms of an overall front armor rating, what are thoughts. Let's assume a PzIIIn as a 7, PzIIIm as a 6-7, thoughts on the PzIVg/h and Shermans used in Sicily and Italy in 1943?

Hi Duke,
These should help. Note: the later versions of the MkIV (G and H) were surprisingly tough customers frontally versus the 75mm Sherman.

B

Battle-scarred and Dirty: US Army Tactical Leadership in the Mediterranean Theater, 1942-1943
Go here – link

- – -

Vulnerability Tests of German Tanks
Go here – link

From a quick search to refresh my memory, they're pretty close.

The Sherman has better frontal armor thickness wise, and slightly better side armor too, though once spaced armor is added to the sides, the ratings are about the same.

I think you'd be fine with rating the Sherman a bit better than the Pz. IVs – just slightly, like you are proposing for the Pz IIIs.

Armor penetration ratings are about the same for the German L43 gun vs. the Sherman's L40 gun.

Blutarski,
Good reference. Below is what I have:

Panzer IV showing armor with compound angles figured in. It may still need some work.

Sherman armor for "WWII Armor and Ballistics" book.

The Panzer IV current frontal armor was only about 50mm thick, bad idea.

Wolfhag

The only caution I would suggest relates to armor penetration statistics. German AP table data assumed a 30deg angle of obliquity, while US AP table data can be assumed to represent penetration at 0deg obliquity (unless otherwise specified) – it makes a difference.

Also, US cast homogeneous armor (for the same nominal thickness) was equivalent to about 85pct of <<<typical>>> RHA. Another issue was that early US cast armor was often not of the best quality (see the "Flawed" notations in Wolfhag's inserted data page above).

Re the frontal armor of the German Mk IVG/H/J, the 90mm and 85mm ratings both included added 30mm post-production applique armor kits.

That is as far down the rabbit hole as I am willing to venture.

B

So in terms of an overall front armor rating, what are thoughts. Let's assume a PzIIIn as a 7, PzIIIm as a 6-7, thoughts on the PzIVg/h and Shermans used in Sicily and Italy in 1943?

I haven't looked at this sort of thing for a while but using a similar sort of scale to what you are talking about, Firefly rules (Rea-Taylor) employs the following armour ratings (F/S/R):

M4, M4A1 – 6/4/3
M4A2, M4A3 – 7/4/3

Pz IIIM – 6/2s/2
Pz IIIN – 6/2s/2
Pz IVG – 5/3s/2
Pz IVH – 6/3s/2

Just one example – lots of other rules with variations on similar rating systems.

The Sherman may have had thicker armour than the later Pz IV, but the gun penetration of each was in no way comparable. The German long 75 had a much higher armour penetration than the 75L40 so a Pz IV could destroy a Sherman at 1600m, whereas despite the thinner armour, a Sherman needed to be within 1200m to destroy a Pz IV (frontally). At normal combat ranges of 1000m or less it didn't make much difference of course.

I think Martin has it about right. Although I think if both were hull down the Sherman would have a thicker turret armor (depending on where hit) and a slight chance of a ricochet because of rounded surfaces.

What I feel is the most researched and historically accurate armor and penetration tables are on the Panzer War website.

Here is a nifty armor and penetration calculator to see the result of a German 75L48 against a Sherman. Use the Advanced Options to see for yourself: wwiiequipment.com/pencalc

What I've done is take the true armor thickness and decreased it 10%-15% if it was cast or had flaws like many early war armor did as Blutarski noted. Then I run it through this calculator for 5 different horizontal angle aspects:
link

The end result is a more historically accurate armor value of the thickness without the player needing to do any calculations. If the calculator gives a compound angle >= 70 degrees the round would most likely ricochet.

I do all of the calculations so the player does not have to so it's just as easy as any other game. It does not need to be painful.

Wolfhag

That is true of the German L48 gun, though the Pz IVG has the weaker, L43 gun, which is generally similar to the performance of the Sherman's L40 gun.

Hi Thresher,
The reference books that I have in hand suggest that the German 75mm L43 was actually a considerably better performing weapon than was indicated in your post.

"Panzer IV" by Thomas Anderson -
By November 1941 the Waffenamt (ordnance office) recorded adoption of the new 7.5cm PaK L/46 in the turret of the PzKpfw IV. Initially called the Pak 44, this weapon should have entered production as the 7.5cm Pak 40 by April 1942. But the weapon's long cartridge (716 mm) prevented installation in the PzKpfw IV turret. For this reason, the rifled Rheinmetall Pak 44 barrel was combined with the breeach of the Krupp L/41 gun, which used thicker but shorter cartridges (495 mm) designed for installation in and armoured superstructure with restricted space.

Analogous to the Pak 44, the new weapon was called the KwK 44. The development sheet quotes the calibre length with L/43, and later an L/48 barrel would follow. This was to simplify production; the early L/43 barrel showed an irregular angle of twist ranging from 6 degrees to 9 degrees; the longer barrel had a ciontinuous twist of 7 degrees.

The KwK 44, now renamed to KwK 40, entered the PzKpfw IV's production line in March 1942. The decision to adopt this new gun for the PzKpfw IV led to cancellation of the Ausf F production but only after issuing 470 instead of the 500 ordered (the number of vehicles produced varies in different sources, though the deviations are only small).

Owing to the situation immediate production of the new long-barrelled version was begun. At the beginning the L/43-armed PzKpfw IVs were designated as Ausf F/2, subsequently all older L/24-armed Ausf F were renamed Ausf F/1. However, soon the name of the new production run became Ausf G. The changeover led to a short loss of production in March 1942, but in April 80 machines were built. The L/43 gun was in production until April of 1943. Initially, a ball-shaped muzzled brake was used, which was soon replaced by a double-baffle muzzle brake.

<snip>

The 7.5cm KwK 40 fired the following ammunition:
7.5cm SprGrPatr 34: this was the standard HE round fitted with impact fuze AZ 23 to be firedwith or without delay.
7.5cm PzGrPatr 39: This was the standard APCBC shell to combat tanks.
7.5cm PzGrPatr 40: As with the 3.7cm and 5cm tank and anti-tank guns , a Sondermunition (special ammunition) with tungsten core was available for the 7.5cm KwK 40 Hartkern (HVAP – high velocity, armour-piercing).
7.5cm GrPatr 38: Hohlladungs-Geschosse, shaped-charge projectiles (HEAT) were an effective and cost-effective shot, though accuracy was reduced by the slow muzzle velocity and high trajectory.
7.5cm NbGrPatr: This round was used for smoke firing.

Technical Characteristics of the 7.5cm KWK 40 L/43
Calibre- – – – – – – – – – 7.5cm
Length of Gun Barrel – – – 3,218mm (L/43)
MV (GrPatr 34) – – – – – – 550 m/s
MV (GrPatr 38 [Hl/B])- – – 450 m/s
MV (PzGrPatr 39) – – – – – 740 m/s (2428 fps) ***
MV (PzGrPatr 40) – – – – – 990 m/s
Rate of Fire – – – – – – – 10-20rpm

*** This lesser MV value is taken from Jentz, "Panzer Truppen". He cites the same PzGr39 MV for both the L/43 and L/48 versions of the KwK40 gun.

By comparison, the Sherman's 75mm gun fired both the M61 APC-T and the M72 AP-T (solid shot) at 2,030 fps.

More later.

B

75mm KwK L/43 – PzGr39 @ MV 2428 f/s
Penetration RHA @ 30deg obliquity
500 m -- 91mm
1000 m – 81mm
1500 m – 72mm
2000 m – 63mm

By comparison ( link ), the US M3 75mm gun, firing an M61 APC @ MV 2030 f/s, had a best penetration @ zero degrees obliquity of 2.8in (71mm) RHA at 1,000 yards. At the same range and obliquity, the M72 AP Shot would penetrate a maximum 3.1in (79mm). A 30deg difference in striking obliquity (US test standard versus WaPruef test standard) is pretty meaningful. Based upon the AP graph for the M61 APC in TM9-1907 Ballistic Data Performance of Ammunition, penetration of 2.8in RHA requires a striking velocity of ~1640 ft/sec at 0deg obliquity; at 30deg obliquity, the graph indicated 2040 ft/sec required, which is 10fps greater than the gun's MV.

If I have done my math correctly …..

FWIW.

B

My reading is that the IVh didn't start rolling off production lines until some time between March and June 1943. By Salerno would they be IVh or g? Units showing up at Salerno, particularly 16Th Pz had been recently refitted. I read the same for HG PzG and others with AFVs at Salerno, as tanks were largely lost in Sicily and just being replaced

Skirts or no skirts at Salerno?

Hi Duke,
From what I can glean fgrom my reference books -

Early 1942 – The Ausf F introduced with hull front and turret front armor increased to a 50mm basis.

4 June 1942 – Hitler demands immediate increase of Mk IV armor to 80mm.

29 June 1942 – Hitler recommended only a limited number (about 20pct of production) to be fitted with the upgraded armor.

8 November 1942 – 50 percent of production was to be fitted with "Vorpanzer" applique armor kits, 30mm face-hardened plates welded to hull front and front superstructure; the turret front remained at 50mm armor basis. Later on, bolt-on kits appeared (still no added protection to turret front). Welded kits deemed standard as of June 1943 and bolt-on kits were discontinued.

The Ausf H entered production sometime in Spring 1943, with front hull and Front superstructure at 80mm single plate armor basis.

Panzerschurzen seem to have been first introduced to the production line in Spring 1943. Special kits were also apparently manufactured and shipped to the front for Mk IVs (and StuGs) preparing for Citadel. My guess is that the H's were the first model to to ferature schurzen as fully standard kit.

Hope this helps.

B

I've always been quite surprised that the IV had its hull armour upgraded but not the turret. Had I to guess, I would have guessed that the thicker armour would be on the turret, where it is helpful when firing hull down.

A propos. Years ago I used to get frustrated by the AP performance stats you often found in books, where they often only give it at one or two different ranges. If you wanted to know AP performance at 100 metres, how do you work it out if you've only got it at 500 yards and 1,000 yards?

It turns out it's quite easy: it's virtually linear. Gravity finally causes the shell to fall to the ground. If firing at 0 degrees elevation, it takes exactly as long to do so as one you have just dropped from breech height, rather than fired. This is such a short period of time that the shell has barely decelerated. So if you plot AP performance over range, it's near enough a straight line.

4th Cuirassier, I think you are on the right track.

My gun accuracy tables use the time of flight for accuracy using 100m increments. With all things being equal, they will have the same accuracy.

So a gun with an MV of 1000mps might have a 75% chance to hit at 1000m and a gun with an MV of 700mps would also have a 75% chance to hit at 700m. A gun known for above accuracy might get a +100m modifier and one known for being inaccurate -100m.

Wolfhag

Regarding the Panzer IV turret:
I think it was a matter of balancing the turret and the tank being nose heavy after adding frontal hull armor. The commander sat directly behind the gun so it needed to have the trunnion mounts outside the turret protected by the rounded cheek armor on the left and right side of the mantlet. The barrel length increase from 43 to 48 made it worse too.

They could not mount the gun inside the turret like the Tiger I. They may have been able to mount it like the Panther but then again more armor = more weight. The Panther had a problem traversing the turret if it was on a slope because it was so unbalanced which is why the radioman had a crank to help it traverse.

The Panzer IV was an interwar tank that had reached the very end of its design life. The tank's suspension had not been upgraded (Upgrading a leaf spring suspension essentially designs a new tank), so every single addition of armor or gun weight was a precarious choice. This was a tank that had gone from 18 tons at the design to 23 tons in 1941. The H variant increased that weight to 25 tons.

Tanks design is all about mission and tradeoffs.

Wolfhag

Interesting tidbit: In the book "German Tank and Antitank" by Hoffschmidt & Tantum there is a photo image of a Mk IV tank mock-up armed with the Panther's 75mm L71 gun.

Also a diagram of PzKpfw 38(t) with a MkIV turret and 75mm L/48 gun.

Can't believe this book is now 54 years old. I still remember when and where I bought it.

B

Duke wrote -

My reading is that the IVh didn't start rolling off production lines until some time between March and June 1943. By Salerno would they be IVh or g? Units showing up at Salerno, particularly 16Th Pz had been recently refitted. I read the same for HG PzG and others with AFVs at Salerno, as tanks were largely lost in Sicily and just being replaced

Skirts or no skirts at Salerno?

OK, tracked down some additional information in "German Tanks of World War II – The complete illustrated history of German armoured fighting vehicles 1926 – 1945" by F. M. von Senger und Etterlin:

"On 19th March, 1943 a Pz Kw IV with additional apron armouring was introduced. This was the Model H (Type 9/BW) (Sd Kfz 161/2), which was in production at that time, fitted retrospectively with this 5mm apron armour. It had 85mm front armour and the long tank gun.
<snip>
Some of these modified vehicles had an anti-aircraft MG fixed to the commander's cupola and were given "Zimmerit" protective coating.
<snip>
Vehicles of the "H" series had no vision slits for the loader and aimer; such slits would have been pointless because of the additional 8mm apron armor which was fitted round the turret. The commander's cupola hatch was no longer double flapped, and was closed by a one piece round cover.

Note – the final Model J appeared in March 1944.

B

@ Wolfhag

Yes, basically if you have AP performance at two ranges, you subtract the figure for the further from that from the nearer, and divide this by the range difference. This gives you a number for AP performance change in mm per unit of range. If you've got the figures for 500m and 1,000m but you need the value for 300m, you just multiply this value by 200, add it to the figure for 500m, and voila, that's the AP performance at 300m.

It even works passably well if you've only got an AP value at one range. As long as you know the muzzle velocity, you just have to find another weapon with a similar MV and where you do have two figures for AP effect. You then just assume a similar slope for both guns, which gives you the answer. When I've done this pro tem and later got hold of more detailed figures my interpolated AP effects have usually been about right.

I wish I'd known this when I was 14.