Accuracy of tanks firing on the move.

[sandy]

Very impressed with your test methodology - thanks for your hard work

[akd]

I would think that perhaps for LOS purposes and small arms direct fire purposes this statement is correct, but even then it must be abstracted as you physically cant see these ruts and irregularities.

But as far as affecting the "to hit" chances of tanks firing while moving over it, the mechanical effects of any of these "abstracted" dips/ruts/irregularities seem to be generically abstracted separately in the "to hit" calculation somehow. Further, I would go on to say that this "abstracted to hit while moving fudge factor" DOES NOT change based on what terrain title the tank is moving on, as my tests seem to indicate.

ie. any abstracted effects on targeting while moving over "grass" terrain (with it's abstracted dips and irregularities) seems identical (or not significantly differnt to) what it is for moving over what is meant to be "rough" terrain (that really would/should affect the "to hit" calculation more significantly).

Keep in mind that if CMBN actually DID take in to consideration the abstracted surface a tank is moving over while calculating it's probability to hit a target, then it would be one of the first games to my knowledge, PC or boardgame, (not even ASL considers the surface type a tank is moving on when determining its "to hit modifiers" for moving fire) that does so. I would consider the implementation of model such a feature in any game as just another small step towards a more realistic battlefield simulation (basically more goodness under the bonnet).

Basically ALL games seem to disregard the surface a vehicle is moving on when determining "to hit" penalty modifiers. All movement, across ANY abstracted terrain type, is just counted as "Moving fire" with possibly a generic modifier maybe simply related to "speed". Would factoring in the current terrain type be that difficult? I don't see a reason why it would be.

I agree, and I don't believe abstract terrain has any effect on firing on the move. Just pointing out that if it did, "grass" would not be our base line for a "smooth" surface.

[dieseltaylor]

I thought this interesting given the nature of the exceptional quality of the Panther gun and the test at 1700+ metres with the MkIV and the Sherman. The Panther was sighted to 3000metres.

In all cases, the great range of the gun should be exploited to the

fullest. Fire can commence at a range of 2000 meters with considerable

accuracy. The majority of hits were accomplished at a range of 1400 to

2000 meters. The ammunition expenditure was relatively low; on the

average the fourth or fifth shot found its mark, even when using HE

shells.

Spielberger. Panther & Its Variants page 160

French experience with the Panther were put to paper in the report

"Le Panther 1947", published by the Ministre de la Guerre, Section

Technique de L'Armee, Groupement Auto-Char,

[ClarkWGriswold]

It was certainly reassuring then to find that the Shermans moving over this terrain, firing at the same rate as before, actually seem to have ABSOLUTELY NO CHANCE of hitting the target downrange when moving. I have yet to detect even ONE hit!

The perfect argument why tanks should not be firing on the move in the first place.

Nice work with doing these tests. It's nice to see that actual changes in the mesh of the terrain cause aiming problems. However, it just seems to underscore the fact that tanks shouldn't be shooting on the move anyway, certainly not in rough terrain or at anything other than very close distances. What sort of hit percentages did you see when firing on the move over grass and dirt? I wish I had the game here at work, because I'd also love to try firing on the move while traveling laterally to the target. Firing while approaching the target is one thing, but firing while moving sideways would be an incredibly difficult shot for any WWII tank to make, but I'd wager that the tanks in CMBN easily score hits after their first or second shot.

[ClarkWGriswold]

I thought this interesting given the nature of the exceptional quality of the Panther gun and the test at 1700+ metres with the MkIV and the Sherman. The Panther was sighted to 3000metres.

I don't think anybody is questioning the accuracy of the guns themselves (especially the Tiger and Panther guns, with their flat trajectories). The problem is the accuracy of the human firing the gun, when that human is on a moving, vibrating, bumpy platform. Imagine how hard it would be to sight in a target using a little eyepiece, rotate the turret to the correct angle using foot pedals, raise the barrel to the correct elevation, etc. while someone else is driving the tank (most likely in a direction other than the one the barrel is pointing) hitting bumps, varying speed, etc.

The chances of getting off a shot under those conditions is very slim, even with a very close and stationary target. With targets 500 - 1500 meters away and moving.... no way you could make a shot like that. If you could, they wouldn't have bothered with gyrostabilized guns, computer range finding, etc. that are found in modern tanks.

[Erwin.Rommel]

I don't think anybody is questioning the accuracy of the guns themselves (especially the Tiger and Panther guns, with their flat trajectories). The problem is the accuracy of the human firing the gun, when that human is on a moving, vibrating, bumpy platform. Imagine how hard it would be to sight in a target using a little eyepiece, rotate the turret to the correct angle using foot pedals, raise the barrel to the correct elevation, etc. while someone else is driving the tank (most likely in a direction other than the one the barrel is pointing) hitting bumps, varying speed, etc.

The chances of getting off a shot under those conditions is very slim, even with a very close and stationary target. With targets 500 - 1500 meters away and moving.... no way you could make a shot like that. If you could, they wouldn't have bothered with gyrostabilized guns, computer range finding, etc. that are found in modern tanks.

During the ww2 era especially in the actual combat even shooting the stationary target can not be very accurate.here is the famous experts lorrin bird's caculation about the accuraccy of the ww2 tank.

FIRST ROUND ACCURACY OF GERMAN GUNS

The following hit percentages are taken from German ballistic tables

(capped AP) and refer to the case where the range is known to a

stationary 2m high by 2.5m wide target, and the random dispersion is

doubled to model battlefield conditions:

RANGE..50L60...75L48...75L70...88L56...88L71

500m........100.....100.....100......100.....100

1000m.... ...95......66......97.......93......85

1500m........68......33......72.......74......61

2000m................16......49.......50......43

2500m.................8......29.......31......34

3000m.................5......18.......19......25

Relative dispersion in the above table follows some unexpected

patterns, with 75L70 being less scatter prone than 88L56 out to

1000m, but after that range 88L56 is slightly more accurate in terms

of repeatability. With regard to 88L71, the scatter pattern is more

diffuse than 75L70 and 88L56 at ranges out to 2000m but then attains

a superior performance at 2500m which increases with range.

German data for their use of the captured Russian 76.2mm L51.5 gun

showed dispersion patterns similar to the 75L48 when APCBC was

fired., with similar hit percentages with a known range.

The 50L60 and 88L71 data applies to both the tank gun and towed

weapons, while the 88L56 figures are limited to the tank gun. Review

of data for the 88mm L56 Flak suggests that that weapon may have

possessed greater dispersion than the tank gun.

The marked inferiority of 75L48 scatter to the other guns is

unexpected., since the 75L43 was used to knock-out T34’s at ranges

above 1000m. It would be interesting to see if 75mm L46 Pak 40

dispersion had the same general values as the 75L48, which came along

at a later date.

It has been written that the introduction of the 50mm Pak in Africa

greatly extended the range of direct fire combat for tank and anti-

tank gun units, and the relatively close scatter pattern and

excellent gun sight quality for that weapon would be superior to the

2 pdr anti-tank gun in both respects.

Using the German figures for doubled random dispersion and assuming

an average range estimate error of 25% with a bell shaped error

distribution (typical results for average crew, based on British and

American firing trials), the following first round hit percentages

were computed against a stationary 2m high by 2.5m wide target:

FIRST ROUND HIT %

RANGE...50L60...75L48...75L70...88L56...88L71

500m...........81......75.....88.......79.....94

800m...........36......34.....51.......39.....61

1100m..........17......15.....28.......21.....34

1400m...........9.......7.....16.......12.....19

Muzzle velocities are 835 m/s for 50L60, 750 m/s for 75L48, 935 m/s

for 75L70, 780 m/s for 88L56 and 1000 m/s for 88L71. All rounds APCBC

except APC for 50L60

A 2m x 2.5m target size was used by the Germans as a reasonable model

for the front view of a typical target tank, which simplified the

calculations. Those dimensions simplify the complex variations in

target width with height (T34 turret front is narrower than hull and

has sloping sides, T34 hull width varies with height, etc.), and

probably assume that ground rolls and folds blocked out some of the

lower tank area.

The above stated estimates for first round hit percentage probably

represent the high side of what would be expected from average troops

in battle, since “nervous and/or fatigue” origin errors were not

considered during the calculations. Under the stress of combat,

people can forget intermediate steps and see things on the gun sight

that are not there. Discussions on the AFV News forum site have

brought out the possibility that unquantifiable human errors may

account for a good share of the reported misses at “sure thing”

ranges.

Regarding second shot corrections after misses, the Germans advised

that bracketing should be used at ranges above 1200m using 200m

increments below 2000m and 400m above that distance. At or below

1200m, "fire for effect" corrections to the initial shot would be

made using various methods that would result in a more accurate

change in shot placement than adding or subtracting 200m.

An American gunnery manual for the Sherman indicates that bracketing

is to be used at ranges over 1000 yards due to gun sight limitations

which restrict the crew ability to make fine adjustments to the gun

setting.

[slysniper]

FIRST ROUND HIT %

RANGE...50L60...75L48...75L70...88L56...88L71

500m...........81......75.....88.......79.....94

800m...........36......34.....51.......39.....61

1100m..........17......15.....28.......21.....34

1400m...........9.......7.....16.......12.....19

These are numbers that could be used to see how the game compares, as to a stationary shot. I bet the game is very close. but as a moving unit, the game really needs to adjust it to a low capability. plus in general, they should just program the tanks to generally stop, take aim and fire. Sometimes I see them stop but they fire ln less than a second after that. that needs adjustment.

[dieseltaylor]

Am I correct in that all test firings are using a fixed gun. Anotherwords the tests do not simulate what the effect is of having these mounted in tanks. To me this is quite an important question.

And going to combat records, and bearing in mind that the Tigers have 93-100% accuracy at these ranges

The 13.(Tiger) Kompanie, of Panzer Regiment Großdeutschland, reported on the armor protection of the Tiger: "During a scouting patrol two Tigers encountered about 20 Russian tanks on their front, while additional Russian tanks attacked from behind. A battle developed in which the armor and weapons of the Tiger were extraordinarily successful. Both Tigers were hit (mainly by 76.2 mm armor-piercing shells) 10 or more times at ranges from 500 to 1,000 meters. The armor held up all around. Not a single round penetrated through the armor. Also hits in the running gear, in which the suspension arms were torn away, did not immobilize the Tiger. While 76.2 mm anti-tank shells continuously struck outside the armor, on the inside, undisturbed, the commander, gunner, and loader selected targets, aimed, and fired. The end result was 10 enemy tanks knocked out by two Tigers within 15 minutes" (JENTZ, Thomas L.; Germany's TIGER Tanks - Tiger I and II: Combat Tactics; op. cit.).

So ignoring the armour - two Tigers kill 10 tanks in 15 minutes. That does not sound that impressive does it if you are 93-100% accurate at stationary targets and have the ability to track and lead targets. So is there a fudge factor between shooting range figures and RL. It is a shame there are no details on the terrain, cover, and number of shells fired.

Russian hits on Tigers 20+ which say there are average 20 tanks means they are hitting once each in 15 minutes of firing.

Tiger crews were probably the best trained tank crews with very high requirenments for gunners but they did have the advantage of a very much larger and heavier tank as a gun platform.

[futon river crossing]

Thanks dieseltaylor for the links, read them both. In one of the links Captcliff gives a link back to the year 2000 and it was interesting. A much milder Steve, I'm sure that if you are an administrator these forums will wear on you, of Battlefront made several posts and they were interesting and informative to read. I read Steve's post in this thread but he didn't address the "firing on the move" question.

Come on Battlefront - let's have your response the "firing on the move question".

[dieseltaylor]

I think[hope ] it is included in v 1.01

[acrashb]

refer to the case where the range is known

While there was some ability to estimate range, WWII was remarkably absent laser range finders with sub-second +-1% accuracy.

Stadimeters are dependent on precise knowledge of target silhouette size for relatively accurate ranging.

[ClarkWGriswold]

I think[hope ] it is included in v 1.01

I've seen nothing so far to indicate that is the case. Until we hear definitively from BFC, there's no reason to believe this is slated to be fixed (though I certainly hope it is).

[Lt Bull]

I have since created, run and observed quite a number of different variant tests on my firing range all related to understanding "moving tank gun firing accuracy". Again I have just focused on the US Sherman tank moving fire (haven't done any comparative tests using other tanks).

I have modified my standard "FLAT" elevation firing lane to create variants on the "0deg target bearing" series of moving fire tests:

- "constant slope" firing range (testing accuracy of moving fire when tanks move DOWNHILL firing at stationary target down hill, and move UPHILL firing at stationary targets UPHILL. This is to understand if there is any influence on moving fire accuracy when target is uphill/downhill or level with firing tank. Not that each of these situations (apart from the need to adjust aim to account for gravity, less when firing down hill), each one of these examples present would present the same kind of "aiming" challenge to the gunner. Essentially just adjusting the elevation of the gun (to account for range variation) as you got closer.

NOTE: the maps don't really have a totally "smooth" incline. They have slight bumps, so if anything you might expect the tanks having a harder time hitting targets downrange (compared to the flat level earlier tests).

SLOPE UPHILL

SLOPE DOWNHILL

- a flat firing range with the target elevated on a ledge at the end. This in theory should present itself as a greater challenge for the gunner to hit the target from a tank moving closer towards it. The need for greater gun elevation adjustment (not just for range adjustment) is needed the closer the tank approaches the target. (note: it was this example where I noticed that tanks have no gun elevation/depression limits). They can fire their main gun at targets sitting above their turrets if needed.

LEDGE

NOTE: Finding a firing solution when travelling DIRECTLY TOWARDS (or away from) a stationary target (ie. target bearing 0deg, or 180deg) (like the tests I have conducted so far) is the least challenging scenario for a gunner in a moving tank. Trying to aim and hit a target that is not in the direction of the tanks motion (a target bearing of 90deg being the most challenging) is much more challenging, as both the vertical and horizontal (this one not being so much a factor when moving directly towards/away from the target) gun adjustments to hit the target are constantly changing. I plan to test moving tank gun accuracy in these more challenging situations later (they just take a bit more work to set up).

Based on observation alone in these "0deg target bearing" moving fire tests which anyone can duplicate by downloading and running the "ready to go from start" saved file games of each test (no need for any numbers dedicated statistical study at this early stage), the moving fire accuracy of the Sherman tank (I have only tested this tank) at ranges even BEYOND 1000m seems to be HIGHER that what I expected. "0deg target bearing" moving fire accuracy around ~1000m could even be 50%.

Feel free to delve in to a more detailed statistical analysis using the "ready to go" save files available in this thread.

Will try to now do some "90 deg target bearing" moving fire tests.