German tank vulnerability

[MikeyD]

I remember saying this back when we were having the very same debate in CMAK, and it goes double for CM:BN. One of the great pleasures of this game is creating test maps and actually testing out our hypohesese. A Stug 700m from an M10 with the hull angled at 10 degrees - A kill or not? Lets test it out! A full-hull PzIV or a hull down PzIV at 800m - whose more likely to survive three round of 75mm fired at it, on average? Let's test it out!

[Battlefront.com]

As a follow up to my last post...

A really good crew is given is a turret to shoot at, then that's what he's going to aim for (obviously). But the opposite assumption is not necessarily true, which is that if the crew is given a full profile shot that the crew will elect to shoot for the turret. The reasons for that have been discussed in this thread.

Put another way... the best of the best of the best crew in the best of the best of the best tank will likely take a center mass shot under most combat circumstances most of the time, regardless of what its theoretical non-combat results might produce.

Steve

[Vark]

Did tankers have the equivalent of the small arms Mozambique technique, (double tap/hammered pairs, centre mass then one to the head) used for a definite take down or when confronting opponents who might have body armour. I'm thinking along the lines of crews getting off some rapid centre mass shots to buy time for a more carefully aimed 'killer' shot at a known vulnerable spot (like the PzIV Turret, Char B1 ventilation grill etc)

[Bastables]

24/7 is not true from the allies perspective. I am sure they were on the lookout 24/7 but fortunately the Germans did not have enough armour for each allied tanker to be spotting a tank once a day.

It was uncommon. I might try and find a couple of diary like first hand accounts that I know of and count how many tanks each of them saw to put it in better perspective.

Especially considering that the German Panzer units where deployed against the British until the Mortain counter attack ( the very end of the Normandy battle). Meaning the US were facing attached StuG's marders and Jadgpanzers Of infantry divisions and corps for the majority of their time in Normandy.

[MikeyD]

Meaning the US were facing attached StuG's marders and Jadgpanzers Of infantry divisions and corps for the majority of their time in Normandy.

Which coincidentally were the very vehicles the German staff reported were ineffective in Normandy dut to their low-mounted gun having to content with raised bocage bases.

[Txema]

I think of a situation where it would be probable that a gunner would aim at a specific point, and that would be when he sees his previous shell hit the target, but not killing it.

Confident of his aiming point (though probably very nervous), he might then adjust a bit to go for the turret or other weak point.

Did tankers have the equivalent of the small arms Mozambique technique, (double tap/hammered pairs, centre mass then one to the head) used for a definite take down or when confronting opponents who might have body armour. I'm thinking along the lines of crews getting off some rapid centre mass shots to buy time for a more carefully aimed 'killer' shot at a known vulnerable spot (like the PzIV Turret, Char B1 ventilation grill etc).

Steve,

Any comments on these situations? I think they could be reasonably common in CMBN...

Txema

[Battlefront.com]

I really don't know how many more times or more ways I can answer the same question, no matter how it is phrased. Center mass is the best chance of scoring a hit, scoring a hit is the best chance of affecting a positive outcome. Therefore, tankers would go for center mass except under near ideal circumstances. We do not feel those sorts of ideal circumstances would come up frequently enough in a CM battle to warrant the effort necessary to make sure exceptionally aimed shots would be restricted to only the specific conditions that a tanker would attempt such a thing.

As for being "confident of his aiming point"... even if the gunner actually correctly identified where his shot went (and that is definitely an iffy assumption to make), remember that gunnery is not an exact science. Even assuming that both shooter and target remained 100% motionless before, durning, and after the first shot (which would be required under this scenario)... the range of error inherent in a single shot can be quite insignificant. Let's say the gunner aimed for the turret and the shot hit the frontal armor. Should he raise the gun on the assumption he aimed too low? Or should he keep the gun where it is and hope the next round's propellent is a little more true to specs?

And what if he aimed center mass and saw the round bounce off center mass. Should he assume that if he raises the aim point a little bit that the gun is still 100% sighted the same as the first shot?

The answers could definitely be such that the gunner does decide to slightly adjust his aim. But in doing so he inherently lowers his chances of striking the target and therefore affecting a positive outcome for the shot fired. Therefore, under what conditions would the gunner decide to roll the dice on a riskier, but potentially better, result? The answer to that is in the previous posts.

Steve

[Battlefront.com]

Did tankers have the equivalent of the small arms Mozambique technique, (double tap/hammered pairs, centre mass then one to the head)

Not that I'm aware of. At least not in a fluid situation. Remember that unlike small arms the number of seconds that go by between tank rounds flying is significant enough to change the entire dynamic of the engagement. By the time that third round is loaded the Tank Commander (or Gunner) should have a pretty good idea about how well the engagement's going. First two rounds might have missed completely, so the taking a riskier third shot would be pretty dumb. First two shots strike, but don't appear to cause any damage, then it's probably that either target and/or shooter are going to be moving because firing two shots tends to attract attention. Etc.

We can all imagine scenarios in our heads where a preconceived solution would fit nicely. But one needs to take that and try to remember how battlefields work... they don't really like being predictable or ideal

Steve

[MikeyD]

All this talk about tank gunnery got me curious so I did a little test. The Sherman's coaxial gunsight was x3 magnification with a 12 degree(+) field of view. I thought 'Hey, I could recreate that in the game!

So I placed a Panther at exactly 500m from my camera, zoomed in x3, then cropped the picture to roughly match a 12 degree field of view. Then I overlayed a Sherman aiming reticule on top of it. 500m is considered pretty much 'point-blank' for AP so the crosshairs would rest right in the center.

See the picture. This, if my estimates and the game engine is close, is how large a Panther would be in the aiming reticule. There's precious little wiggle room between the lower bow, upper bow and turret front. The "center of mass" appears to be about the size of a small kidney bean.

I fully expect someone to hop on my test with a "Not even close!" That's part of the fun of testing things out.

[Elmar Bijlsma]

So if I get this right, Redwolfs point is that for example versus a hull up Sherman an elite PzIV crew shooting at centre of mass might consistently keep hitting the glacis, wheras a green crew is more likely to spread the hits around, on the less angled (but admittedly thicker) turret for a greater chance to penetrate.

But Steve is in a better position to judge if this is an issue, us not knowing what the spread of an elite PzIV might be. I reckon that at all but point blank ranges the spread should still wide enough for even an elite gunner to spread the hits around.

Nor is it likely to be very important from a gameplay POV as players are unlikely to be able to use this to their advantage. As the recipient of fire this would require them knowing what the oppositions skill is. As the firing party it matters not much as you will have to make do with what you've been given to shoot with and at.

But it is indeed something that should be kept an eye on in case it is skewing results after all. So far the AARs don't have me alarmed. We'll see for ourselves soon.

[Magpie_Oz]

OK here's a thing.

The longest range tank v tank shot ever performed was by a Challenger 1 mounting an L30 rifled gun. I forget the exact amount but the range was over 5000m.

Although it is not something that is done very often, I know that the L30 can group 3 rounds in a circle 300mm across from 1000m, on a range, stationary, known environmentals, level ground, target and shooter same height, modern FCS etc.

Wind the clock back 70 years and place the tank in combat and I reckon the group of a WW2 tank gun would be lucky to have the entire tank as the mean point of impact rather than any specific part, regardless of the experience of the crew. To hit the tank was the objective if you managed to hit a particular weak point all well and good but there is no way you can place a round "within 2 inches" or on the mantlet or any other such thing.

I would think that an Elite crew would be better at estimating the various factors that effect the shot thus giving them a higher chance of a hit, rather than a tighter group. The Wittman gunner, Bobby Woll, would leave his sights set at 800m and the estimate the offset required from there, simply by his greater experience. This meant he could fire sooner and more accurately than a gunner who had to muck about setting the sights etc. Combat experience shows the tank to fire first is usually the victor

[Michael Emrys]

That's my thought as well. I think the advantages of a superior crew would be to be better able to estimate range, thus a higher chance of a first round hit, and speed of getting the gun reloaded and corrected for a second and subsequent shots.

Michael

[jjhouston]

This, if my estimates and the game engine is close, is how large a Panther would be in the aiming reticule.

So the aiming circle is 10 mils in diameter. The gap between the circle and the horizontal stadia lines is 5 mils. The apparent sizes of the target forms in your screen shot compared to the reticle is about 7 mils for the Panther giving its side and about 3.5 mils for the Panther showing its frontal aspect.

Coincidentally, the hull length of a Panther is just short of 7 meters, its width is a little less than 3.5 meters. Accordingly, the apparent range is about 1000 meters.

At 500 meters, the apparent length of a Panther should be about 14 mils, perhaps about like this:

[Vark]

Just a though, reading another forum, what happens if the gunner fires centre mass but deliberately over-estimates the range (the example in the forum was a WWII trick of 700m when you know it is 500m). The round gets fired off quickly but is more likely to hit high, perhaps targetting a known weakness (turret thinner than hull). The comments by seemingly well-read members all stated it was a technique only experienced crews used so perhaps this could be modelled?

[Claymore]

That's my thought as well. I think the advantages of a superior crew would be to be better able to estimate range, thus a higher chance of a first round hit, and speed of getting the gun reloaded and corrected for a second and subsequent shots.

Michael

Dropping in to agree. When working in the CMSF timeframe the weapons platforms of the modern era did not require consideration of range finding. In the WWII timeframe however crew quality should be a major consideration when calculating hit percentages.

That's why I also want to take this chance to remind the BF gods that my thread regarding LOS and range recalculations is feeling mighty lonely.

Cheers

MRD

[Wrath of Dagon]

It seems logical that an experienced PzIV gunner would aim a little above center mass at close range (< 500 m) knowing he's likely to be facing a Sherman. If he doesn't, then we might have the result that being hull down is worse than hull up and at an angle, which seems ahistorical. I guess we can test that out once the game is available.

[Thomm]

I fully expect someone to hop on my test with a "Not even close!" That's part of the fun of testing things out.

At a range of 500 meters, the Panther hull with a length of 6.87 meters should cover roughly 6.87 / 500 = 0.0137 rad = 0.787 degrees of the view field. Magnified by a factor of 3 this gives 2.362 degrees. Given a total field of view of 12 degrees, the Panther hull should cover 100 * 2.362 / 12 = 20 % of the field of view. In your image it is only about 6 %.

Best regards,

Thomm

[WineCape]

Currently have a take on 1-hit chance % for regular crews, at 400m stationery, both head on & non-hull down (M4A3 versus PzIV(H). Time will tell what Charles/Steve will make of my results, whether they are bang on target or outliers

[Battlefront.com]

Elmar BijlsmaSo if I get this right, Redwolfs point is that for example versus a hull up Sherman an elite PzIV crew shooting at centre of mass might consistently keep hitting the glacis, wheras a green crew is more likely to spread the hits around, on the less angled (but admittedly thicker) turret for a greater chance to penetrate.

Yes, that's his point. In theory it has merit, but in practice it only matters if the degree of accuracy and surrounding circumstances combine to affect a noticeable outcome. So noticeable, and might I add predictably reproducible, that the crews would even try for it.

As I've said, I totally agree that there are circumstances that could crop up where a very good crew would aim off center mass. But I disagree that those type of situations would come up very often during the course of a normal battle. I've already stated the conditions that I think it would happen and why they don't pertain to CM.

Having said that, if we had endless amounts of development time to burn I would support a detailed modeling of when a crew might shift aim point off center mass and purposefully try to hit a specific major component of a tank. Aiming for tiny weak points is just silly, so that's not even up for consideration ever

I would think that an Elite crew would be better at estimating the various factors that effect the shot thus giving them a higher chance of a hit, rather than a tighter group.

Correct, and that's what CM focuses on. The biggest advantage an experienced crew has is the speed of an effective engagement. Take a Regular crew on a shooting range, tell them they have 20 minutes to get a shot off, and I bet they could do almost as good as an Elite crew at typical combat ranges. But tell the Regular crew to do this in 10 seconds... well, let's just say I'd expect there to be a little difference in results when compared to the Elite crew

The Wittman gunner, Bobby Woll, would leave his sights set at 800m and the estimate the offset required from there, simply by his greater experience. This meant he could fire sooner and more accurately than a gunner who had to muck about setting the sights etc. Combat experience shows the tank to fire first is usually the victor

This is what is called "battle sights" for American tanks. It allows for very quick and accurate range estimation at normal engagement ranges. Or more importantly, ranges where the variables are more likely to change rapidly AND the threat of retaliation (i.e. the chance of being seen, hit, etc.) is quite serious. Kinda like how if you're in a fight with pistols at 20m having a bulky scope mounted will likely be a liability.

So yes, the point you (and others) make is absolutely what I've been saying all along, though not explicitly in terms of engagement times. So I will amend my pervious statement:

The tank that shoots first has a distinct advantage over a target that hasn't shot back yet. The tank that hits first has a distinct advantage over a tank that misses since any hit has more potential benefit than a miss. Aiming center mass both speeds up engagement as well as increasing the chance of a hit. Therefore, aiming center mass is the way to go almost all times in all combat situations.

Just a though, reading another forum, what happens if the gunner fires centre mass but deliberately over-estimates the range (the example in the forum was a WWII trick of 700m when you know it is 500m).

The problem again comes down to the granularity of accuracy being asked of the gunner and gunnery systems. The gunner is already "winging it" even under the best of circumstances. He's guessing wind speed/direction, he's guessing range, he's guessing how well his gun is boresighted, he's guessing relative speeds, he's guessing where true center mass is (an oblique target might not be so obvious), he is probably guessing at what the target is in the first place, etc. Now you're suggesting adding yet another guess which is "at x range how much will y adjustment affect impact location". Each guess decreases the chance of success, so keep that in mind.

Look at a modern tank fire control system. The computer knows EXACTLY how many meters (probably centimeters for all I now!) the target is, what the wind speed and direction are, what the temperature is outside, how hot the barrel is (I assume), and a host of other factors that even the most experienced WW2 gunner would have to almost blind guess at. So yes, it's logical for an Abrams to aim at a turret or something instead of center mass, but there again you're missing the point of why "overmatch" capability has been such a long sought after attribute -> if you can penetrate an enemy tank anywhere you hit, then there is no need to aim for anything other than center mass.

It seems logical that an experienced PzIV gunner would aim a little above center mass at close range (< 500 m) knowing he's likely to be facing a Sherman. If he doesn't, then we might have the result that being hull down is worse than hull up and at an angle, which seems ahistorical. I guess we can test that out once the game is available.

Yup, you can test it out for sure. But just remember that the theory that's been proposed here is extremely unsound to start out with. So even if the results come back "suboptimal", that doesn't mean they would be any better with some sort of "super sniper aimpoint" feature in play.

Steve

[Wrath of Dagon]

It could be tested against say a 10% offset from center, of course that test would have to be internal.

[Vark]

With you to a point Steve, but a Veteran crew would know what the likely deviation would be if you over-estimated range and if in a defensive position, or using crude range finding techniques, know the rough range to target. At 500m there is going to be a negligable ballistic drop, for even the 75 L40, so a centre mass aim point would more likely hit the turret, not guarantee it, but be more likely to hit it. I cannot remember where I read it but analysis of KO'd tanks in WWII and post-war engagements showed 2/3rds of the rounds struck the turret because gunners were prone to over-estimating the range.

Finally found the good link about German tank optics I'd been hunting for:

http://www.weaponsofwwii.com/forum/viewtopic.php?t=2296

And for the PDF file link found in the above link

http://www.75thguards.com/ww2online/downloads/Zheriz_Ziess_Sight_Guide.pdf

[akd]

There was also something about firing HE with a fuse delay at the ground in front of dug in personnel in the hopes of getting a ricochet airburst above the intended targets. No idea how often this was attempted or what the success rate would have been.

Michael

Hey, that's in the manual...

(from US '43 Tank Gunnery Field Manual)

[Magpie_Oz]

"At 500m there is going to be a negligable ballistic drop, for even the 75 L40,"

Muzzle Velocity of a 75mm Pak 40 : 933m/s = 500/933 = 0.5359s to 500m

(This is ignoring a whole stack of other variables as well, the big one being air resistance that will slow the projectile and thus taking longer to get to range and hence dropping more.)

"Ballistic Drop" or just simply the drop due to gravity = 0.5 x g (Gravity 9.8m/s/s) x Time Squared.

= 0.5 x 9.8 x 0.5359^2

= 1.407 m (!)

Let's say we are shooting a Sherman, 2.74m high, aim at the centre and you are aiming at a point 1.37m off the ground or 1.37 down from the top of the turret which ever way you look at it.

If you set your sight as if the range is 700m you will be expecting a drop of 2.758m, more than the height of the target so you would need to aim into the ground to hit it, aim at the centre and your shot will miss by 1.4m

[JasonC]

Magpie Oz - but the arc of the shell is a parabola (up to air resistence), so it is only falling from the apex reached in flight for half of the total time of flight. At 500 meters, the total time of flight is 2/3rds of a second, but the time of fall from the apex is only 1/3 of a second. (Before then the shell is rising on the arc caused by firing with the barrel elevated from the horizontal). t squared is thus 1/9, and the fall from the apex of flight is only 16/9 = less than 2 feet.

Basically, shots out to one second of total flight time are "bowling" (tracking in the height dimension basically irrelevant because the drop from the apex is so small). Shots at 2 seconds of flight time, thus one second of fall from the apex, 16 feet, are "golfing" (need to get the range right as well as the direction). In between, it transitions from one to the other.

For the 75L48, that means 750 meters and under, no problem; 1500 meters and above, very hard; in between, range estimation starts to matter, and by the 1500 meter distance it is the overwhelming difficulty in making the shot successfully.

[Magpie_Oz]

No the shell is falling from the instant it leaves the barrel, it has to there is nothing holding it up anymore.

It inscribes a parabola because of gravity accelerating the shell downwards. i.e the further it goes horizontally the faster it goes vertically down.

Yes the barrel is elevated and that is to allow for the 1 to 2 meter drop calced above, air resistance will slow the projectile thus taking longer to reach the range and therefore falling further.

If you do the calcs for all ranges:

100m 0.056m

200m 0.225m

300m 0.506m

400m 0.901m

500m 1.407m

As you say it is a parabola and you can see in the first 100m it only drops 0.056m in the last it drops 0.506m, 10 times more !

Check out this link http://en.wikipedia.org/wiki/External_ballistics#Bullet_drop there is a groovy table (if Physics is able to be groovy?) there that shows the varying drop due to drag calculations and comparing that to empirical radar measurements. They show similar results to my basic calculations