"1/285th scale WW2 Tank vs Tank in the Laptop/WiFi era" Topic

We have been using the Panzer War tables – panzer-war.com – to resolve our tank vs tank combat due to its decent accuracy determining penetrations. It works well in the 15 tanks per side range but for larger games we need things to move faster. Currently our level of detail to resolve combat is;
1) Roll for hit using the gun/ammos hit probablity at range/target.
2) Roll for the hit location
3) Roll for the adjustment to penetration (accounts for angles, edge effects, etc)
4) Compare the adjusted penetration to the armor to see if it is a kill/moblity kill/no effect

We would like to "dumb things down" and get it down to one roll of the dice, after inputting just the range, target (including aspect), and firing gun/ammo.
It seems to me that in the age of portable laptops (connected by Wifi to the internet) someone might have done something similar? Or there may be a different computerized rules set or online tool that can do this?
If nothing exists I may have to input all his tables and write some code to get it all in one roll…
I would hate to reinvent the wheel of something similar is already out there.

If you can read Python, I have a bunch of scripts that will

1. Calculate projectile velocity decay over range given a projectile mass, calibre, and ballistic coefficient, or back-fit a ballistic coefficient for a projectile of specified mass and calibre give a velocity decay history. It includes the usual Gavre drag curves, but you probably only need G1 and G7.

2. Given an angle of fall and a striking velocity, an estimate of projectile dispersion in each axis, and the dimensions of a rectangular target, produce the probability of a hit assuming Gaussian errors.

3. Calculate expected penetration of semi-infinite targets at normal impact for non-deforming projectiles of specified mass and striking velocity using any of 11 different empirical penetration formulae, the best of which I think is Dehn's formula (which needs you to specify the ultimate tensile strength of the target plate).

4. Calculate expected penetration of semi-infinte targets at impact angles up to 80 degrees by eroding projectiles, using the Lanz-Odermatt equation (not needed for WW2, this is only applicable for very high velocity long rods).

I have been vaguely intending to glom all these scripts together in a grand ballistic toolkit (including other handy things like a couple of personnel incapacitation models), but have never got a round tuit.

However, if you fancy doing the integration work yourself, you would be most welcome to copies of the Python source code.

All the best,

John.

Thanks for the offer John.
I'm probably too time constrained to learn Python.
I started an MS Access DB to try and do this… see how that goes.

What on earth do you need a database for?

A spreadsheet I could just about understand…but a database?

All the best,

John

You could do it either way – I am more familiar with Access and had the key data already in table form.

Got it all done and it works well. Enter your tank, gun/ammo and range and it uses a VBA Random derived number to help determine the result. Found some nice sound effects for miss/kill/immobilized. Actually I'd like to use the ones from WOT but can't convert them. Gonna be much quicker than rolling the dice 3 times per shot!

One table I don't have is something to account for the T/D ratio when determining the penetration. Any thoughts on if its effect is significant enough to warrant an adjustment to a penetration calculation for WW2 tanks (1939 – 1945)?

The empirical penetration equations I am used to normally have their results interpreted as depth of penetration into a semi-infinite target. While it is known that the dynamics of penetration and perforation differ between thin, thick and very thick targets, I have never seen any empirical formula take this into account.

The only time I believe T/D ratio matters at all in practice is where you have a thin plate ("thin" being defined as less than the shot calibre) under attack at an angle, and the main plate failure mode is by petalling. In this case I believe the plate will perform less well than one would otherwise expect. For WW2 I would not expect these conditions to apply most of the time, as one expects an armour-piercing round to perforate a good deal more than its calibre, so the plates being attacked are by definition seldom "thin". Where they are, things are probably so badly against the plate that there is no need to make things any worse. And a lot of thin (in the everyday, rather than ballistic, sense) platefitted to armoured cars was homo-hard, and therefore more likely to fail by plugging or shattering than petalling.

So my recommendation would be to ignore it.

All the best,

John.

I wouldn't worry too much about the T/D thing. That sort of over-engineers things. I have data on real gun vs. tanks tests and the results are not in line with straight T/D factors. There are a lot of other factors that confound the whole process, so concentrating on one factor is a fool's errand.

If one had the entire engineering data of the shell, shell hardness, nose cap armor hardness and quality one might get the results of a formula to fit in some curve but that doesn't happen.

Nathan Okun's Face Hard ballistic formula and M79APC armor formula takes T/D into account. But again major factors are the shell, cap and armor quality. Comparing the results of this to real worlds tests only gets to +/- 15% of the real results.

Thanks all. That makes complete sense. And less work for me!