"Armor Effective Thickness" Topic

Back some 20 years ago, I had a a formula I used in Excel that would convert Armor thickness to Effective Armor Thickness. Something involving cosine….

But I don't have that anymore. Anyway, I just bought "Anthology of Tanks" and the data for the Panther Tank doesn't look right to me. Can anyone give me the front Armor thickness and angle for the Panthers (A, D, G) and tell me what that translates to in effective thickness.

I can't figure out how he came up with his armor for the upper hull. Seems way to high…even for sloped armor. But I'm not sure.

He lists for Panther G
Hull as 60mm@55 degrees
Superstructure 80mm@55 degrees
Turret 110@11 degrees
Mantlet at 100mm@round

Some of you guys are walking encyclopedias…figure you might be happy to share in the data.

I often go to the WWII Vehicles site. They use various established publications for stats. They do break down the various models of Panther as far as the stats you are requesting.

wwiivehicles.com

Their Panther G page

link

55 degree is close to 60 degrees.

At 60 degrees, line of sight armor thickness is doubled, so…..

Check Google Images – there are charts for Sine and Cosine values, which you can then use to multiply vs. armor thicknesses for LOS protection.

Sounds about right if the Hull means lower hull. Superstructure would be glacis. Of course those are spec thicknesses. Actual measured thicknesses are a few millimeters more.

Just multiply by 1/cosine as that gets you in the ball park. Effective thickness over 1/cosine is determined by shell type. HEAT penetration is almost the same. Effective armor vs. an ogive shaped shell is higher but then complications come into the picture when compound angles are involved. So it is better to attach the variation or multiple over 1/cosine to the shell and not the armor.

Panthers front armor is equivalent to ~140 mm

There's formulas for working out LOS armor here:

link

The wiki entry on Panthers lists them as all having the same front armor, not sure how accurate that is.

The effective slope changes if the firer is higher or lower than the target, or if the target isn't completely level, and whether or not the shot comes directly from the front or at an(other) angle.

Calculating the thickness of sloped armour using the cosine method has virtually nothing to do with predicting the effective resistance of sloped armour. There are many sites around which will explain in detail the reasons for this.

If you want a simple set of armour numbers which take into account slope effects and various other factors and where somebody has already done the work for you, I recommend the AFV stats used in ASL. Last time I looked these were also freely available…

The slope increases the effective thickness, but there is also a chance the round will simply bounce off. Then of course you have to consider what the armour is made of and any special processes (like face hardening) that have been applied.

The variations of 'real world' hits are catered for by the dice.

"The variations of 'real world' hits are catered for by the dice."

….. True. But only true if the rules in fact make allowance for such things. Many rules take a simplistic 'yes/no' approach to armor penetration issues.

It is without question a sticky issue to deal with – consider the counter-intuitive issue of the 2-pounder AT versus German tanks with face-hardened frontal applique armor in the earlier part of the desert campaign.

B

Armor quality differs as well. Rather than merely stating the effective armor thickness better sources will give the Rolled Homogeneous Armor equivalent allowing one to compare not only thickness but quality and protection or penetration.

Here are a couple of calculators. I can't vouch as to how accurate they are:
link

wottools.net

Cast armor is about 85% and if the armor angle is > 70 degrees it may bounce off unless …………

Mantlets can make it even more complicated. A 110mm curved mantlet is going to be cast armor. However, since it is curved there are going to be areas it is 30-70 degrees sloped.

What is the quality and brittleness?

The point I'm trying to make is that it is very hard to come up with a definitive value and then you have different issues with the AP shell type and design. It depends how far you want to take it.

I've looked at Anthology of Tanks and their references. I'd say they've done an excellent job for a wargamer to use.

Wolfhag

Yes i agree with all of your comments. Which is why I take a hard look at how wargame rules come up with their armor ratings. Of course a lot of rule sets blend the armor rating into a single factor, others use one for the hull and one for the turret. Some are incredibly simplistic like battlefront WWII and others pursue extreme accuracy such as Panzer War. In defense of BattleFront WWII a tank on the board is 2-3 tanks so the use of basic armor ratings is understandable.

I recently purchased Micro Melee and Armor Anthology by Bennett P. Lacey. I looked up the Panther Armor and couldn't understand how he came up with such a high number for the Panther upper hull (270)

I used the website that @zoneofcontrol recommended and I also came up with 140mm. If you use the website and put in a second compound angle you end up with a rating that is closer to what the author is using. So it's possible that the tank data used in both publications is all flawed based on a mathematical formula error?

Cast armor is about 85%
It looks like the British Ordnance Office changed their test armor quality from MQ (280 BHN) to 115,000 tensile strength (237 BHN) US standard somewhere between 1943 and 1944. The equivalent effective difference of 90% of MQ.

PDF of study of small scale test on equivalent armor protection based on armor quality:
PDF link

This site has a free calculator for dealing with compound angles: you input the armor thickness, the primary angle, and the secondary angle, and it give you the relative thickness.
link

Thanks Don, that is the sight that I used.

Another factor to keep in mind is that net obliquity is not solely a function of armor slope. Horizontal obliquity of the line of fire relative to the target vehicle itself is also a material influence. I know that German tankers were trained to utilize a slightly slanting approach to take advantage thereof; other nations presumably did so as well. German Wapruf AP tests incorporated an obliquity component of 30deg (judged to be the average in combat) to reflect that fact.

And, yes, the quality of US cast armor was inferior to that of regular RHA.

B

Yes. A lot of armor-pen. data incorporates a 30-degree angle, so that you have to retro-calculate from that to get the penetration for a straight head-on hit -- THEN figure in the actual angle(s) for this particular shot!

expanding on donlowry

the British armor tables which I am familiar with and i think the most common use armor at 30 degree angles and IIRC average penetration of 5? shots
BTW it changes what can penetrate what by quite a bit if the right angle can be achieved

This is from a source I would trust to determine the compound angle (horiz + vertical).

[URL=http://s1276.photobucket.com/user/wolfhag/media/compound%20angle%20table_zpso7aitouj.png.html]

Wolfhag