StuG BS discussions

[Yoozername]

My current theory is that when they went to 80mm solid armor for hull and 'loaders' side front, they also went for superstructure 80mm.  Eh, maybe photos show?

[Mobius]

Reading through the text of Spielberger's StuG book I came across a passage where it said "After the basic frontal armor of all Sturmgeshutz had been increased to 80mm thickness, the one remaining weak point was the gun mantle." This is some time prior to November 1943 when the cast gun mantle was introduced.

I did come across another upgrade. June 1944 they began adding 30mm plate to the 80mm driver's plate. The factory would add by using bolts. In the field this could only be done with welding the plates on.

[Mobius]

ORIGINAL: Yoozername
Armor Piercing rounds have a trait of 'bouncing' downward once they make it through angled armor. The Soviets called it 'normalizing' but can be generally understood as something taking the path of least resistance. This applies mostly to full-bore sized projectiles. Its even seen when a handgun bullet passes through a windshield that is sloped. The bullet makes it through easily but is defledted downward.

In the case of the sponson, the Soviet round might make it through, but is then attacking the next plate at a downward angle. The cap has been stripped from the penetrator and it is possibly destabilized and cracked after hitting face hardened armor.

This would work against the StuG armor complex. The 30mm plate probably wouldn't change the path very much but even if changed by just 4-5 degrees it would work against the 50mm plate behind it. This plate at about 15 degrees would be impacted at only 10-11 degrees from the path of the deflected shell.

[Edit] I don't know if ogive shaped shells do normalize. I have some strobe shots of armor penetrations in my old Military Technology magazines. Most show modern long rod penetrators normalizing (a little). But I don't recall any ogive shells doing it.

[Edit2] Well running a 76.2mm ogive through my Naval Ballistics program does result in it normalizing. A 2000fps impacting 30mm at 51-degrees show that it exits the plate at 42.6 degrees at 1393fps. So theoretically it normalizes it by 8.4 degrees.

[WilliePete]

hey Yoozername, just out of curiosity please give us a shot of the full vehicle, front and side. This Stug was lovingly restored and would like to see what it looks like overall. Thanks!

[Yoozername]

http://www.archive.org/stream/Panther-fibel-BetriebUndKampfanleitung/Panther-fibel-BetriebUndKampfanleitung1944119S.Scan#page/n19/mode/2up

The Panther Bible has some fast film of AP 'normalizing' after penetrating sloped armor of 45 deg.

I believe those photos come from the Littlefield collection. BTW, Littlefield has passed on.

http://svsm.org/gallery/StuGIII-family

[Ratzki]

The problem with just comparing thickness in mm's of armour is that different types of construction yeilded very different armour toughness and brittleness. Forged steels may approach twice the strength as cast in the same thickness, and the differences are huge around curves, unlike fabricated plate. Cast plates require a lesser technology to fabricate and the process is faster and can be performed at smaller factories, but protection would be very much determined on the size of the metal grains in the poor rather then the thickness of the poor. The grain size can vary considerably and would have probably increased as the war went on and production speed won out over quality. Even comparing rolled steel is not a straight forward look at mm thickness, it is again controlled by final grain size of the steel being used, also the hardening proccesses that it went through, there is also the nickel percentage in the steel as well as a whole list of other factors that would make severe differences in the protective values per mm of thickness, and would not be consistent from one vehicle to the next as sources would vary from part to part, specially as the war went on. Thickness, brittleness, grain size, welding process, alloy composition, hardening technology used, and the list can go on.

[Yoozername]

Forged Steels?  Do you mean Rolled Homogenous Armor?

[Yoozername]

Note above the gun's recuperator there is a 'inverted U' bar (painted white). It is bolted on by the two bolts seen in the picture to its left, and two other bolts not seen but on the right. This bar 'tops' the gun once its installed. It connects the superstructure along the front also. In front of this bar is the mantlet. The mantlet actually overlaps this bar and some of the superstructure. Again, note the thickness of the bar.

[Yoozername]

Carefully inspect the bolted on armor around the visor. The plates do NOT lay directly on each other. The bolts themselves have conical sections that are in between the plates. That lifting eye is actually a side plate that is welded in and prevents viewing these bolts conical sections.

The other side shows that the bolted on armor IS laying on the armor underneath. This is is a good shot of the 'box' mantlet. Note the front plate is welded to the barrel protector. The gun's barrel actually recoils back into that thick cylindrical section. The vertical 'V' shaped piece at the front of the box mantlet is held on by the bolts that attach it to the 'box'.

[Yoozername]

[Yoozername]

Sorry about that pic size.  but it demonstrates the overlap of even the box mantlet with the superstructure.

It also shows the 'toe-in' from the vertical 'shields' on either side of the mantlet area.

[Yoozername]

Excellent photo showing how StuK40 weapon was changed out. Note the 'U-Shaped cross bar' laying on vehicle front near visor. It would seem roof had to be removed, cross-bar removed, gun carriage unbolted and then the old weapon was removed and new weapon installed.

Again note superstructure armor and the mantlet, once installed, overlapping that armor.

[Prince of Eckmühl]

Now, I understand. You've haven't been describing a "late-model" Stug.III, but rather, the "Bob Fleming" vehicle:"

http://www.andreaslarka.net/ps531016/ps531016.html

What total tripe Lewis.[8|]

Is your sole intent to simply confuse your readers, or is this the continuation of your Jabberywocky/Snark routine by other means?

In "Mr Tittles" honor, let me post an image of the Stug's true source of invincibility, CONCRETE:

[Yoozername]

Pat yourself on the back prince.  You are the texas-troll on a saturday night!

Eh, no hot-dates lately? That's Ok, I see that yappy lapdog in the picture and feel I know everything about you.

Edit: I have to be honest, your trolling, while desperate and obviously 'long' thought out has me puzzled. Try to explain to me, using your extensive texas education, what you think you are saying, what you think it accomplishes, and how anyone would care. Thanks. Troll.

[Mobius]

ORIGINAL: Prince of Eckmühl
let me post an image of the Stug's true source of invincibility, CONCRETE:

From that photo it looks like the source of invincibility would be the white stars.

[Yoozername]

Yeah white stars.  Nice one Mobe.  US forces used captured StuG in 44 and 45.  What that picture, and 'lapdog-texan's' rant has to do with the discussian of the StuGIII and Soviet t34/76mm can only be explained by a texan.  With a lapdog?

[Yoozername]

ORIGINAL: Mobius
[Edit2] Well running a 76.2mm ogive through my Naval Ballistics program does result in it normalizing. A 2000fps impacting 30mm at 51-degrees show that it exits the plate at 42.6 degrees at 1393fps. So theoretically it normalizes it by 8.4 degrees.

I suppose 2000 fps might represent a T34/76 firing at approx. 200 meters or so? Its interesting that your results show the shell has lost over half its energy from striking the first plate. I would assume this plate is face-hardened armor.

[Mobius]

ORIGINAL: Yoozername

ORIGINAL: Mobius
[Edit2] Well running a 76.2mm ogive through my Naval Ballistics program does result in it normalizing. A 2000fps impacting 30mm at 51-degrees show that it exits the plate at 42.6 degrees at 1393fps. So theoretically it normalizes it by 8.4 degrees.

I suppose 2000 fps might represent a T34/76 firing at approx. 200 meters or so? Its interesting that your results show the shell has lost over half its energy from striking the first plate. I would assume this plate is face-hardened armor.

That test was on remake of M79apclc, Okuns rolled plate penetratrion program. Sadly it doesn't match most actual test results so I would not use it for game data. It does give interesting engineering info on penetrations. I did run the same shell vs. face hard armor and got similar results.

[Mad Russian]

ORIGINAL: Yoozername

Sorry about that pic size.  but it demonstrates the overlap of even the box mantlet with the superstructure.

It also shows the 'toe-in' from the vertical 'shields' on either side of the mantlet area.

It doesn't demonstrate anything. It's too big to see anything.

Resize it.

Good Hunting.

MR

[Mobius]

For some reason the angled armor is over rated in engineering formulas vs actual tests. I don't know the reason why. But as can be seen in some photos the Germans put tracks over the 70 degree high angled superstructure armor to add protection where it shouldn't be needed.

During the early 1950s (maybe 1953) The Yugoslav army had access to vehicles, guns and ammo from several WWII participants. They made side by side test of guns on various targets. In one case a T-34/85 was used as a target for a US 76mm gun and German Pak40 gun.

Code: Select all

T-34/85: Hull 46@60° 350BHN, Turret 90mm rounded.
 Yugo standard penetration is 50% of shell weight passes behind armor.
 
 76mm M1 (from M4A3E4 tank) firing AP and HVAP.
 M79 AP penetrates glacis @ 1100m
 M53 subcalibre penetrates glacis @ 1200m
 
 M79 AP penetrates front turret @ 900m
 M53 subcalibre penetrates front turret @ 1500m
 
 Yugoslav Pak40 vs. T-34/85 renamed German ammo to 'M' code.
 
 75mm M40 PaK40 firing AP, HVAP.
 M39 AP (PzGr.39) penetrates glacis @ 1300m
 M40 subcalibre (PzGr.40) penetrates glacis @ 1200m
 
 M39 AP penetrates front turret @ 1000m
 M40 subcalibre penetrates front turret @ 1250m

Theoretically the rounded 90mm turret would be penetrated at far longer range than the high angle 45mm glacis. But it doesn't.
As the saying goes:
"In theory, theory and practice are the same. In practice they aren't."