AFV tactic puzzler

rexmonday · Post by **rexmonday** » Thu Sep 21, 2000 2:59 am

Here's a question for one of the mathematicians out there that has a good grip of the new penetration system:

In earlier versions of SP the best defense for an AFV when confronted by another AFV was to turn and face it - this brought the thickest armour (normally the frontal plates) to face the enemy - thus giving the best chance of success.

However, the new penetration modelling has modifiers for angle of attack, does this mean that it is no longer a good idea to face the enemy head-on? Or is it better to pivot the AFV so that any incoming shells will not impact at 90 degrees to the armour plates, but instead will hit either the front or the side plates at between 30 and 60 degrees?

Warhorse · Post by **Warhorse** » Thu Sep 21, 2000 3:31 am

Yah, try to give 'em the 30 degree, makes for some serious richochet's!!!

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Mike Amos
Meine Ehre Heisst Treue

Tombstone · Post by **Tombstone** » Thu Sep 21, 2000 3:40 am

Is 30 degrees on front armor worth the risk of hittin side armor? Even at an increase in slope? That probably depends on the tank. Also, you cant control the turret as precisely so you have to live with it facing head on. I would imagine that tanks with significant side armor would benefit from this tactic, whereas a Panther for example might lose out in the math.

Tomo

rexmonday · Post by **rexmonday** » Thu Sep 21, 2000 5:38 am

The 30-60 degree figure is just a guess, but I think that is how it would work out given that we are playing on hexagons. I would have been able to frame the question better if I had been able to recall the word 'perpendicular' when writing it.

Yeah, I see that for some tanks like the Panther with tin plate sides, then the last thing you want is a side hit, but if we take a 'generic tank' (although there ain't no thing...) which has moderately good armour all round, with a reasonable increase in thickness to the front, then does it make sense to go for increased angle of incoming away from the perpendicular over relying on plain heavy metal between you and them.

I guess we would have to take into account the slope with respect to the vertical of the side and front plates as well.

I definitely do not know the answer - that is why I am asking if it makes any sense.

Warhorse · Post by **Warhorse** » Thu Sep 21, 2000 6:29 am

This seems to work rather well, with little instance of side hit, that I've seen, sometimes, yes, but generally this will save your skin;-) That is 30-60 to the fellah you DO see, now his buddy you don't see, who is now lookin at your juicy side aspect....uh-oh!! Have fun guys!!

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Mike Amos
Meine Ehre Heisst Treue

Grisha · Post by **Grisha** » Thu Sep 21, 2000 7:37 am

I prefer to just take a defense stance, and go hull down.

Grok · Post by **Grok** » Thu Sep 21, 2000 11:44 am

On advance or attack, I usually just "shoot n scoot"...Using the leap frog method, I approach known enemy positions with a combination of smoke and at an angle, if possible. Otherwise it's a straight line approach.

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understanding requires patience

Grok

Grumble · Post by **Grumble** » Thu Sep 21, 2000 7:08 pm

FWIW,
It was doctrine for German crews to always attempt to attack at an angle to defenders instead of perpendicular to their line. Approaching at a slight angle is an historical tactic, besides making good game sense.

Paul Saunders · Post by **Paul Saunders** » Fri Sep 22, 2000 4:19 am

Originally posted by Tombstone:
Is 30 degrees on front armor worth the risk of hittin side armor? Even at an increase in slope? That probably depends on the tank. Also, you cant control the turret as precisely so you have to live with it facing head on. I would imagine that tanks with significant side armor would benefit from this tactic, whereas a Panther for example might lose out in the math.

Tomo

I don't think so, provided you keep the side at a sharp angle. Whenever a shell hits the info box tells you which part of the tank was hit, the penetration number of the shell and the "effective" armour thickness (taking the angle into account). You'll need to set the message delay quite slow to have time to read all this.

Do some tests, design a simple scenario, arrange some tanks at various angles, then take pot-shots at them and read the messages. Side hits at sharp angles come out with a huge effective thickness, you may be surprised. It's usually easier to penetrate the front armour at the gentler angle.

If the shell penetration is higher than the armour thickness number but the tank isn't destroyed, that means the shell penetrated the armour. You've probably done some internal damage, even if you can't see what it is, but then again, maybe the crew got lucky and the shell went straight through without hitting anything.

mogami · Post by **mogami** » Fri Sep 22, 2000 4:24 am

I just turn the tank head on. As for slope doen't the front armour on good tanks have "Slope" I thought they were built so the armour was not flat.

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I'm not retreating, I'm attacking in a differant direction!

rexmonday · Post by **rexmonday** » Fri Sep 22, 2000 6:34 am

ahhh... but some tanks also have a pretty good slope on the side which can mean that they come out with a pretty good effective armour rating

Paul Saunders · Post by **Paul Saunders** » Fri Sep 22, 2000 6:52 am

Originally posted by Mogami:
I just turn the tank head on. As for slope doen't the front armour on good tanks have "Slope" I thought they were built so the armour was not flat.

Varies from tank to tank. T-34s have excellent front sloped armour, just try hitting one of those on a hilltop above you.

mogami · Post by **mogami** » Fri Sep 22, 2000 10:09 pm

Ah yes I love my T-34's, I am experimenting now with paratroops too. I wonder how big a transport I'd need to move a T-34? I noticed also that the Soviet 57mm AT has a higher penetration rating then their 76mm.

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I'm not retreating, I'm attacking in a differant direction!

rexmonday · Post by **rexmonday** » Sat Sep 23, 2000 2:37 am

Here's my attempt at the maths.

Assumptions:

1. Both the firer and the target are at the same level: there is no difference of elevation between them. Thus there is no modifier for the vertical angle of impact, other than that provided by the slope of an armour plate. An incoming shot is treated as one which flies parallel to the ground.

2. If a target is angled to the firer, then hits are distributed across its visible faces according to the angle they present. Thus a tank is treated as a cubic mass. When one plate is perpendicular to incoming fire it shall receive 100% of hits; when at 60' it shall receive 67% and the side at 30' shall receive 33% of incoming fire; and if an angle of 45' was presented on both faces then an equal distribution would occur.

3. All hits are assumed to strike the body of the tank. The same mathematics could be used to calculate the effective armour of the turret, however, then a distribution between turret and hull would be required to be calculated. Similarly, top hits (which I believe can happen very infrequently on the level(?)) are ignored.

4. Ricochets do not occur. See CONCLUSIONS at the end of this post for further discussion.

5. The angle is taken to be 60' on the front and 30' on the side.

Steps:
1. calculate effective armour for both side and front armour. This is given by:
thickness/cosine(slope)

2. modify this by the angle of incidence of a shell on each of the faces. This is given by:
thickness/{cosine(slope)}{sine(incidence)}

3. calculate the average effective armour which is presented to the firer on the basis of the ratio fo angles of incidence:

frontal angle(thickness) side angle(thickness)
------------------------ + -----------------------
90{cosine(slope)}{sine(incidence)} 90{cosine(slope)}{sine(incidence)}

Results:

T34:
frontal armour 47mm slope 60
side armour 40mme slope 40

If the front is struck at the perpendicular it shall receive 100% of all hits and shall produce:
effective frontal armour 94mm

If angled so that the frontal plates are at 60' from the perpendicular, then the side plates are at 30'. This is taken into the calculation:

effective frontal armour 108mm
effective side armour 104mm

Thus average effective thickness, taking into account the ratio of frontal to side hits (ie. 2 hits to the front for every side hit) becomes:

106mm

This can be seen to be a benefit of +13% over a face on confrontation.

Pzkdfw-Vd (Panther)
Front at 90' = 139mm
Front at 60' = 161mm
Side at 30' = 104mm
Average = 142mm
Conclusion: an insignificant 2% increase

Sherman III
Front at 90' = 77mm
Front at 60' = 111mm
Side at 30' = 76mm
Average = 99mm
Conclusion: a 16% increase

Comet I
Front at 90' = 69mm
Front at 60' = 80mm
Side at 30' = 50mm
Average = 70mm
Conclusion: a 1.5% increase

Conclusion:
It seems that any increase in angle will provide, on average, some benefit. The much feared side armour hit is not as dangerous as might have been assumed, because any strike against it should have to travel through it at an angle along the plates, thus noticeably boosting the protective value. This is further modified by the assumption that hits shall be equally distributed according to the angles that the plates present to the firer.

For both the Panther and the Comet as calculated above there seems to be an insignificant increase in average effective armour, however, here be tigers - the Comet risks an incoming shell having to penetrate only 50mm of side armour instead of 69mm of front armour. The Panther can suffer a hit against 104mm instead of 139mm.

A ratio could be worked out to determine whether any benefit could be generated by angling any given tank, one which depends upon the ratio between the effective front and side armours as hit at 90' and is then modified by the faces they present to the firer.

One should of course note that the average as calculated above is a suspect one - having a good average doesn't help if it opens up the possibility of an easy penetration should an unlikely side impact occur.

What has also been ignored is the fact that tanks rotate when giving their first shot of OP fire. This would bring the frontal plates back to perpendicular to the line of impact. The new OP fire routines in version 4 mean that this can be declined by the controlling player, in order to retain angles of incidence. I have only had version 4 for a short while and can't really comment on this.
What has not been taken into consideration is the occurence of ricochets. The likelihood of a ricochet increases with the angle away from the perpendicular to the plates. Thus both shells impacting on the front and side plates of an angled tank should generate more ricochets. This may be enough to alleviate the dangers which are present in a side hit: a sharply angled side should generate a lot more ricochets. I do not know how the mechanism of ricochets operates. (and indeed, most of the maths above is highly suspect...)

Similarly, one should be aware that 'tailpipe' hits can occur. A shell of just about any calibre can knock out a big heavy tank. I have had the honour of having Wittman's Tiger shot out from under me by a Stuart... I did laugh though. I believe the SP2 code had one method of generating such critical hits, but that SPWAW operates on a different basis.

The formula above will probably come out screwed when I post this...

Paul Saunders · Post by **Paul Saunders** » Sat Sep 23, 2000 8:53 am

Very interesting. I'm no expert on this but I'd just like to add a few points.

1) As you suggested, the greater the angle the greater the chance of ricochet, so a side hit at 30 degrees is far more likely to bounce off. I think this more than compensates for the thinness of the armour.

2) APCR, in spite of having a higher penetration potential, has a much higher chance of ricochet. Tanks armed with this tend to use it first in a battle making the initial contact with enemy tanks more dangerous. Because of this it's even more important to angle your tanks in the early stages of a battle. Later on, when they've run out of APCR, angling becomes less important for tanks with thin side armour.

3) Whilst your calculations seem fairly sound, bear in mind that the game throws in a random factor to the angle. This is to represent the fact that moving tanks won't always be at exactly the same angle, due to undulations in the ground, small directional changes etc. Even stationary tanks are assumed to make small positional changes.

Also, a 50 metre hex is a pretty large area and a tank could occupy any position within that hex (the actual size of the tank is much smaller than the icon suggests - the scale is wrong). Different positions within a hex would mean different angles.

Additionally, slight changes in your aim would result in hitting a different part of the tank, which again would mean a slight difference in angle.

Anyway, the upshot of all this is that if you fire at the same tank at the same angle repeadedly, you'll notice (if you look at the hex info box) that the effective armour thickness changes each time you hit the target.

This prevents the whole business of armour penetration becoming the exact science that your post implies. Whilst your mathematics are very useful as a guideline, the random factor allows for "lucky" shots, so it's best not to take the maths too literally.

My experience is that the random factor tends to produce more non-penetrations and ricochets rather than damaging hits, so it tends to work in the target's favour.

Having said that, it can sometimes be a good idea to fire repeatedly at a strong tank even if you have little or no chance of penetrating the armour. This is partially due to the small chance of a critical hit, but mainly due to the fact that external systems can be damaged - optics, guns, radio masts, suspension etc. and also the crew can be stunned etc.

I've tried repeatedly pounding King Tigers with Shermans until many were damaged to the point that they were no longer effective as fighting machines. Of course I lost a lot of Shermans in the process...

The moral of this story is that there's more to AFV tactics than just working out the maths. The maths are certainly interesting and a good guideline, but remember bouncing APCR, the random factor, critical hits and external systems damage.

rexmonday · Post by **rexmonday** » Sun Sep 24, 2000 6:40 am

Paul, I take all your points on board.
The game introduces a random angle into any shot, but I think this will still be effected by the angle the tank presents, so that it might be actual angle of incidence +/- 20'.
I am aware that the maths are no real use in individual instances - it is just that I had been thinking about the old tactic of _always_ keeping the front armour pointed straight at the target. It seemed to me that this was fine for all the other versions of SP, but might be questionable in SPWAW.
I had never really considered the expenditure of APCR early in the game. I shall go away and think about this one the next time I play with tanks.

Paul Saunders · Post by **Paul Saunders** » Sun Sep 24, 2000 9:38 pm

I first realised the importance of conserving APCR in one battle against the Russians. I wasted all my APCR on the T-26s and T-34s that first appeared.

Then the KVs appeared!!!

Charles22 · Post by **Charles22** » Mon Sep 25, 2000 5:53 pm

I may be mistaken here, but if you have a variety of tanks, and Gerry certainly does, if that's what we're talking about in going up against the Russian stuff, you'll find that some 'types' don't have APCR and some do. Of course all of them have slots for those shells, but at various stages I would suggest the various variants get fluctuating APCR. What I'm trying to say, is that if you're trying to conserve APCR, perhaps the easiest way to do it, is to limit your early fire to variants which have none, or at least not fire with all the units that have them, then later, if you get the KVs you were expecting, you can have those units concentrate specifically on those tanks (and of course have the non-APCR tanks help out in order to suppress them too).

What you'll find, unless I'm mistaken again. is that the PZ35T may have APCR for a few monthes, and then at another stage it does not. I also think that if you find one tank with APCR, then ALL the tanks of that same variant will. The PZIVC doesn't have any ACPR in '39, but the PZIVD may very well have in 10/39. I don't know if the APCR is being loaded onto tanks for the variant type or the gun type. In other words I don't know if you kept the PZIVC well into '41, if it would receive APCR, just because the latter variants of the PZIV were getting them.

Paul Vebber · Post by **Paul Vebber** » Mon Sep 25, 2000 6:28 pm

Each seperate unit defined in the OOB's have a distinct ammo loadout. Depending on the dates of avialabilty, different ammo loadouts are possible for a given vehicle type (depending on how many "units" have been defined representing the same unit - ie 6 lbers with and without APDS). Also the "reduced ammo loads" option will sometimes make a unit with a small number of special shells have none.

[This message has been edited by Paul Vebber (edited September 25, 2000).]

Charles22 · Post by **Charles22** » Mon Sep 25, 2000 6:51 pm

Thanks Paul. If I understand you correctly, excepting limited ammo, the same platoon may have a tank with no APCR, while the others do, correct? That's done by tank type and time, isn't it? In other words a tank platoon may get APCR for some of it's members from '39-'43, but not thereafter (for those few who have that long a life), or not get it in '39-43, but the later years?