88mm KwK 36 L/56 accuracy test and some ideas

[Guest machineman]

More rangefinder info:

The longest recorded distance for optical rangefinder controlled gunfire, successfully firing on a moving target from a moving battleship, is 26,400 yards, achieved in 1940 by the British. These rangefinders were designed around a particular gun, and the distances at which they were accurate were determined by the range of the gun. In the U.S. Navy, the Mark 41 (1930s) and Mark 75(1950s)had objectives eleven feet apart, a near focus of 1200 yards, and maximum useful range of 20,000 yards. These were made by Keuffel & Esser, weighed about 1200 pounds, and had 147 glass elements, including lenses, prisms, wedges, reticles, mirrors, and frosted elements.

[Guest machineman]

And yet more:

"Subject of stereo rangefinders for military use. Fact: Stereo R.F. is more accurate than coincidence but the operator of the stereo system must be carefully selected. We have experienced how easy it is for some to review a stereo pair, while very difficult for others. This screening was missed early on."

"I recall the following story of the WWI naval battle of Jutland in which the British, using coincidence rangefinders confronted the Germans using stereo R.F.s. The first salvos demonstrated the superior accuracy of the stereo systems, but as the battle progressed the tide changed and the stereo ranging fell apart. In subsequent analysis as to why stereo was best at the beginning but terrible during the heat of battle revealed the loss of stereo perception by the stereo users. Under stress they saw 2 images rather than the fused images of a depth scene. Of course the coincidence users were not rendered useless by the stress."

[PzKpfw 1]

<BLOCKQUOTE>quote:</font><HR>Originally posted by Paul Lakowski:

John , I think what this thread also shows is that while we all know a thing or two about armor and penetration, enough to question games that model this poorly....the truth is we know 'diddly' about the real question about whether you can even hit the target let alone penetrate. Robert just related to us that the 17 Lb could kill at 2-3 km s but couldn't hit much beyond 1km.

<HR></BLOCKQUOTE>

Agreed Paul below is what Robert suplied the Tanker's list with tonight its an excelent read note the error in estimation & the comment on precise aiming at weak points:

A little looking into the accuracy of the 17 pdr has turned up the following, as alluded to previously:

"We constantly tested and adjusted gun and sight and tried to get a hit first shot, especially at short range where the blast [obscuration]problem was acute." -- Douglas Gardner, loader of Firefly Nottinghamshire Yeomanry, Normandy 1944, as told to George Forty in _M4 SHERMAN_ Blandford Press, 1987

"Gunnery practice was common and many knocked out German tanks which littered the area were gradually reduced to scrap as accuracy improved."(referring to gunner practice in the field by the 1st Hussars Regt. a Canadian unit in Normandy, following their taking of heavy casualties shortly after D-Day, AFV-NEWS May-Aug.'88.

From the above one can infer that gunnery could be poor due to lack of training and practice, and that the sights were in need of constant adjustment. The latter is likely true, as Tom points out, for any high

velocity tank weapon.

Here's a bit from AORG Memo No. 514:

The errors made in sight adjustment on a distant object have been ascertained. These p.e.s. obtained were 0.9 mins in elevation for the 6 pdr, and 1.9 mins. for the 17 pdr. These figures are based on 12 readings for the 6 pdr, and 11 readings for the 17 pdr, and express the variation of sight adjustment under varying conditions by A tk Nos. 1

[gunners] who had recent operational experience in NW Europe on present equipment. [report goes on to suggest that the statistical sample may be too small to conclude that the 17 pdr sight alignment is really that much worse than the 6 pdr].

"In the case of the 17 pdr the maximum range for hitting the tank (1000yards) is less than the maximum range for effective penetration, which is on the order of 2000-2500 yds in the case of the PzKw VI [Tiger I]. Even at 1000 yds the dispersion of the weapon is not sufficiently small to allow the accurate pin-pointing of aim on to known weak spots of the armour." -- Ordnance Board Investigation No. 659, Dec '44, referring to "17 pdr on Land Service mounting firing AP." The paper goes on to say that the error in accuracy was primarily due to poor ballistics, that

is, erratic flight path. The paper supposes this may have been caused by projectile yaw brought on by excessive clearance between projectile body and gun bore, and/or by muzzle vibration while firing. The paper urges that the innaccuracy of the 17 pdr be investigated.

Further data on the BALLISTIC DISPERSION, of head-on tank targets is presented:

6 pdr APCBC/1200 yds: 30%

17 pdr APCBC/1200 yds: 36%

75mm Q.F. APCBC/1200 yds: 19%

This is just about the opposite of what I would expect, but there it is. The 75mm QF is the lowly M3, 40 caliber gun as found in most Shermans. The above figures include an estimated 17% range estimation error, considered a typical combat condition.

Pure ballistic dispersion is given, without range error:

6 pdr Mark IV APCBC: 1.5 minutes

17 pdr APCBC: 1.0 minutes

75mm APCBC: 0.9 minutes

For the mathematically inclined, one minute is equal to 0.296 mils.

<BLOCKQUOTE>quote:</font><HR>

One other thing it shows me is that when you guys are pushed you can do research too Too many times I see these debates being a battle of mere hearsay , with debates of 'how many angles on the head of a pin'.

Its a very sobering thing to wake up one day and realize you know next to nothing about something you value so much...at least it was for me <HR></BLOCKQUOTE>

Yes Paul it is we all learn thats the good thing on these threads.

Regards, John Waters

------------------

"We've got the finest tanks in the world. We just love to see the

German Royal Tiger come up on the field".

Lt.Gen. George S. Patton, Jr. February 1945.

[This message has been edited by PzKpfw 1 (edited 11-16-2000).]

[Guest Big Time Software]

Machineman wrote:

<BLOCKQUOTE>quote:</font><HR>Isn't it possible that the big jump in accuracy came from better crew training in long distance gunnery, better optics, and high powered rangefinder use? All stuff the Germans had at least on the 88's? What other factors could there be?<HR></BLOCKQUOTE>

You are overlooking the most obvious possible difference -> the gun. The average US TANK gun (as opposed to TANK DESTROYER) in WWII ETO was the short, low velocity 75mm gun. The 76mm certainly started to show up in large numbers towards the end of the war, but I suspect they were still way less than half. But what was it in Korea? The high velocity 76mm and 90mm guns. Big difference.

This is why we have to be VERY carefull to NOT go around quoting a few numbers as if they actually mean anything specific. That is what has kept this discussion going so long Stuff like the number of hits from WWII, Korea, and later are useless unless we know EXACTLY how those numbers were derrived. Guessing in the dark about their origins isn't good science.

Steve

[This message has been edited by Big Time Software (edited 11-16-2000).]

[Paul Lakowski]

An oldie but a goody...the old Panzer Battles board game came with the following info on US gunnery

% first round hit with APDS ammo vs tank size target standing target[static]

<PRE>

500m 1000m 1500m 2000m 2500m 3000m

WW-II 76mm 87% 21% 5% 3% 2% 2%

Korea 90mm 90% 65% 31% 14% 6% 5%

Today 105mm 95% 87% 55% 26% 14% 10%

</PRE>

Today would be 1979 so I guess thats M-60A3 level Lazer Rangefinder, while Korea would be coincidence rangefinder plus analogue computer[??] and WW-II would be visual estimation [maybe assisted by pltn leader with stadi binoculars[??].

Robert makes the comment about ± 25% accuracy on range estimations for the Brits Vs ± 10% for the germans. Ogorkiewcz notes that visual estimation is ± 25-30% [ intensive training can reduce this to ± 20%], while stadi is ±15-20%. I remember hearing that the Germans trained extensively on speed and accuracy of shooting ....that would start with good range estimation.I'll have to ask Robert about this.

[Guest Big Time Software]

Paul,

That is an oldy

Assuming that these numbers are even close to correct, check out the 2000m+ numbers for each weapon vs. the numbers below. It would appear that the combo gun and "sights" (including everything used to aim the gun here) improvements hugely increased the sub 1000m accuracy, greatly improved 1000-2000m accuracy, but then the improvements start to taper off.

For example, there is a 10 fold improvement in accuracy for a 105mm gun at 1500m vs. the 76mm, but only a 5 fold increase in accuracy at 3000m. This is especially significant because 2% for the 76mm leaves a LOT of room for improvement, yet the 105mm only scored 10%. Interesting

But of course, the same basic questions about what these numbers mean still remains. Still, if the numbers are even in the right ballpark they do indicate how hard it is to hit at long ranges even with far better guns and sights than what were available to ANY side in WWII.

Steve

[This message has been edited by Big Time Software (edited 11-16-2000).]

[Paul Lakowski]

<BLOCKQUOTE>quote:</font><HR>Originally posted by Big Time Software:

Paul,

That is an oldy

Assuming that these numbers are even close to correct, check out the 2000m+ numbers for each weapon vs. the numbers below. It would appear that the combo gun and "sights" (including everything used to aim the gun here) improvements hugely increased the sub 1000m accuracy, greatly improved 1000-2000m accuracy, but then the improvements start to taper off.

For example, there is a 10 fold improvement in accuracy for a 105mm gun at 1500m vs. the 76mm, but only a 5 fold increase in accuracy at 3000m. This is especially significant because 2% for the 76mm leaves a LOT of room for improvement, yet the 105mm only scored 10%. Interesting

But of course, the same basic questions about what these numbers mean still remains. Still, if the numbers are even in the right ballpark they do indicate how hard it is to hit at long ranges even with far better guns and sights than what were available to ANY side in WWII.

Steve

[This message has been edited by Big Time Software (edited 11-16-2000).]<HR></BLOCKQUOTE>

Yes this is true, As my Serb friends figures suggest, the bulk of the gunners would have difficulty on a real battle field even though they did alright 'home on the range'...But theres one guy in every company whos a 'super gunner' ...

So when your reading an account of shooting accuracy in battle , is it the 'average guy' or the 'super gunner '? Whos going to use accounts of the guy in the company who never can hit anything?

[PzKpfw 1]

<BLOCKQUOTE>quote:</font><HR>Originally posted by Paul Lakowski:

But theres one guy in every company whos a 'super gunner' ...

So when your reading an account of shooting accuracy in battle , is it the 'average guy' or the 'super gunner '? Whos going to use accounts of the guy in the company who never can hit anything?<HR></BLOCKQUOTE>

Good question Paul, IIRC the US referred to these crews in Co's as 'sniper tanks' the crews in a plt who stood out above the others I believe their was even as report done by the US Army on the feasibility of enhanced training to get all crews to the sniper level but it was inconclusive.

Speaking of modern ranges one of the key advantages US tanks has reportedly had vs Soviet/Warsaw Pact tanks was that our tanks could engage at long range Ie, 2500 - 3000m due to our superior FCS while the Soviet tank LR engagement capability was only 1500 - 2000m with guns and longer ranges with tube launched wire guided munitions.

Tank gunnery ranges, despite the current FCS's has not increased that much since WW2 as 2000 - 2500m is still considered a LR hit, and even the longest range kills in the Gulf were under distances achieved in instances by German WW2 tank & TD crews.

Even the M1A2 Abrams FCS can not shoot the b@lls off a fly at 2000m, as even it can't target an specific area to fire on a vehicle with pinpoint accuracy , Ie, you wont shoot an aerial off a BDRM 2 or aim for that hatch etc, though you will have an better chance then say in a Panther of getting close to your mark.

Concerning WW2 optics Robert Livingston's recent post on the Tanker's list concerning US & German optics is relevant to this thread as well as previous optic threads IMHO as it affected accuracy:

<BLOCKQUOTE>quote:</font><HR>

In my opinion, it was not the "stadiametric" quality of the German sights which helped, but the optical quality, so the gunner could

actually see the target clearly. The target was magnified more, sharper, and in a larger field of view than in Allied sights.

This made all the difference, in my opinion. It should also be pointed out that US sights had markings of a standard size, against which objects of known size could be measured, as outlined in US training manuals. I don't think this was stressed as a method in US training. In my opinion, the US training manuals give better info,on the whole, on how to estimate range than the German Tiger and Panther fibels. I think it was mainly a hardware problem which held back US tankers: lousy quality optics.

<HR></BLOCKQUOTE>

Regards, John Waters

------------------

"We've got the finest tanks in the world. We just love to see the

German Royal Tiger come up on the field".

Lt.Gen. George S. Patton, Jr. February 1945.

[This message has been edited by PzKpfw 1 (edited 11-16-2000).]

[Conall]

Steve et al,

Here's some reasonably good empirical evidence that you might find interesting. Please note that the ranges are not known for the first shot, but they do appear to assume that it is known for subsequent rounds (a little optimistic IMO 3-4 rounds seems to have been required to establish range on average).

<BLOCKQUOTE>quote:</font><HR>

WO 291/180, "Accuracy of anti-tank gunnery."

Ranges in yards, target assumed to be Pz VI size.

Probability (%) of hitting static hull-up target with first round:

<PRE>

GunOK for...500 1000 1500 2000 2500

6 pdr line 100 100 96 87

range 87 33 13 3

both (hit) 87 33 12 3

17 pdr line 100 100 100 98 93

range 98 46 20 10 5

both (hit) 98 46 20 10 5

</PRE>

Probability (%) of hitting static hull-up target after first round:

<PRE>

Gun 500 1000 1500 2000 2500

6 pdr 100 86 59 41

17 pdr 100 94 71 50 36

</PRE>

Probability (%) of hitting moving target (direct-crossing at 15 mph) after first round:

<PRE>

Gun 500 1000 1500 2000 2500

17 pdr 86 48 26(e) 16

</PRE>

Probability (%) of hitting hull-down target with first round:

<PRE>

Gun 500 1000

17 pdr 59 18

</PRE>

Probability (%) of hitting static hull-down target after first round:

<PRE>

Gun 500 1000 1500 2000 2500

6 pdr 85 43 22 14

17 pdr 88 51 29 18 12

</PRE>

Comments and corrections

These values are those plotted on the graphs in the report; the value marked (e) is interpolated from other data points. The overall shape of the fitted curves in each case is sinusoidal.

This report recommends that the maximum range of engagement for 6-pdr and 17-pdr ATk guns be considered 800 and 1000 yards respectively. The criteria stated for maximum range of engagement for a statically-sited ATk gun are:

50% chance of first-round hit on a static hull-up target;

90% chance of subsequent rounds hitting a static hull-up target;

50% hits on a hull-up direct-crossing target moving at 15 mph after MPI roughly corrected;

50% hits on a static hull-down target after MPI roughly corrected.

The first table clearly shows that errors in range have a much more important effect on accuracy than errors in line.

Penetration ranges against Pz VI for each gun (ammunition not specified) are stated as being 800 yards for 6-pdr on the front, 1600 yards on the side, and 2000–2500 yards for 17-pdr. Hit probability is therefore regarded as a more important limitation on maximum engagement range than penetration.<HR></BLOCKQUOTE>

regards,

Conall

[This message has been edited by Conall (edited 11-17-2000).]

[Jeff Duquette]

Conall:

Great stuff...infact I posted that info several pages back on this thread. With your seemingly easy access to Bovington Archieves is it possible to get the entire write-up on this particualr War Office Study? The comments provided are actually John Salt's I beleive. It would be interesting to see the War Offices commentary on this...if there is infact any supporting documentation.

[Jeff Duquette]

Just an added question...we have Tigerfibel, and FM 17-12 as potential sources of contemporary gunnery info. Does anyone know what the British Armys equivelent field manual might be for WWII tank gunnery training?

[PeterNZer]

Is this the dark side? The evil side of Peng? Seems so! Feel the size!

Anyway

just reading good old 'Panzer Leader' and interested that Guderian notes that in the extreme cold on the east front the Mk4's sights were useless, (no creme stuff to keep them working.. whatever that means, fogging i guess), and that the first run of Panther's had terrible sights

There! Some good hard data for you

tee hee

PeterNZ

[Paul Lakowski]

<BLOCKQUOTE>quote:</font><HR>Originally posted by PzKpfw 1:

In my opinion, it was not the "stadiametric" quality of the German sights which helped, but the optical quality,so the gunner could actually see the target clearly. The target was magnified more, sharper, and in a larger field of view than in Allied sights.

This made all the difference, in my opinion. It should also be pointed out that US sights had markings of a standard size, against which objects of known size could be measured, as outlined in US training manuals.I don't think this was stressed as a method in US training. In my opinion, the US training manuals give better info,on the whole, on how to estimate range than the German Tiger and Panther fibels. I think it was mainly a hardware problem which held back US tankers: lousy quality optics.

<HR></BLOCKQUOTE>

Geeez that must be the reponse to my question, can't wait till I get home to read it

[Jeff Duquette]

PeterNZer:

<BLOCKQUOTE>quote:</font><HR>Anyway just reading good old 'Panzer Leader' and interested that Guderian notes that in the extreme cold on the east front the Mk4's sights were useless, (no creme stuff to keep them working.. whatever that means, fogging i guess), and that the first run of Panther's had terrible sights.<HR></BLOCKQUOTE>

Interesting. I am in the middle of a book called "Commanding the Red Armies Shermans" by ?Loza? Recently interpreted into English. Loza relays a story in which he ambushes a lagered platoon of Tiger I's in February of 44. The German crews had apparently placed cloth or leather covers over their sights and periscopes to keep the snow off\out and prevent the optics from fogging. Needless to say Loza's Shermans got the best of these blind Tigers.

[Guest Big Time Software]

Oh boy. I think you guys are now starting to understand how difficult it is to do a simulation

The one fact that has come out from this disucssion is that there are few facts. Or at least few that can stand on their own without similar facts calling them into question.

First of all, as we have all seen here, reliable and non-contradictory evidence about [insert variable mechanical/physics thingy here] is pretty tough to do. And that is for the more well known things. But toss something like the likelyhood of optics fogging and oh boy, ain't we got fun

If we were talking about modeling to the nth degree everything in, say, three or four different AFVs... that is one thing. But Combat Mission has so many AFVs that this is simply not a possibility.

So what we need to do is work with factors that are more generalized. We can't spend our time simulating the x different models of sights on y differnent tanks, depending on model or date of production. The data for this isn't there to begin with, but we certainly don't have the time to muck around forever with these details.

What does this all mean? Abstraction. If we can find a general way to lessen the abstraction, while maintaining the overall balance it provides, we are all ears. Or in the case of this BBS, eyes But we must be VERY carefull to not give this or that system a bonus/penalty without doing so for every system based on some pretty decent reasoning.

Specifically, in this thread the argument for applying an accross the board accuracy increase for German tanks vs. Allied ones of the same period (i.e. in CM) is still questionable. Some evidence suggests that such a change would be correct, other evidence suggests that it would be incorrect. Since our standards for making changes like this are high, a much stronger case still needs to be presented before we change one line of code. If such a case could be made, I can assure you that Charles would be more than happy to change the code around.

So please understand that the resistance to change is not based on any sort of unwillingness to make alterations to the way the game works. Quite the contrary, we have a very long and well established record for changing stuff based on good cases for change. And that is something we intend to keep on doing until the day we stop making games.

Steve

[Conall]

Steve,

I agree with your stance on the issue & overall I think you've done a superb job in CM. I think part of the problem here with complaints that the German guns don't seem accurate enough is that some people are confusing accuracy with spotting. IMO accuracy involves all the factors required to hit a target once it has been spotted i.e the crew's ability (not least to judge the range), the combat situation (are they already under fire?) the optical quality of the sights, the quality of the ammo (it's ballistic characteristics, notably trajectory & average dispersion at a given range), environmental factors etc. (I could go on ad nauseam, it's a very long list ). From what I've seen of the game you've done an excellent job of this. As you say no model will ever be perfect & compromises have to be made & I think you've done that very well.

Where I have some doubt is in the initial spotting aspect, specifically at ranges over 1000m. This is mainly determined once again by crew ability & whether they're buttoned up or not, target size, and the optical quality of the sights/binos. The last of these principal factors can add a huge advantage - one which the Germans historically possessed throughout most of the war. Their sights although having a magnification similar to those of the Allies 2.5x (exception Tiger I L, Panther A, G & Tiger II, all had dual power 2.5x & 5x), had almost double the field of view (25 degrees) & far better optical clarity. This allows you to pick up targets far more easily, not least because you have to move you own sights less which allows you to spot enemy vehicles much more easily, especially if they're moving. This is why I find the ability of the Stuart to spot a Tiger I @2000m-1500m without being spotted (see tests posted earlier) somewhat disturbing. Given the state of the optics in the Stuart (dreadful M38 sights - Jeff could you post an image of them?) I think that the opposite situation is rather more likely despite the relative size discrepancy. This of course doesn't mean that the Tiger should then have an almost mystical ability to hit the Stuart, as spotting has little bearing on accuracy (except for the ability to judge the fall of shot as John's quotation from Robert Livingston suggests). I don't think anything I've said is a compelling reason to change what you've written into the game but I do think that it raises enough issues that if you have time it might at least be worth reconsidering the game's spotting mechanisms rather than deciding simply to leave it unchanged. Apologies if you've already heard all this on the board before and thank you for so patiently listening to our concerns.

Jeff, I've emailed David Fletcher at Bovington and he's looking into those War Office Documents, if they're in the library he'll make me a copy otherwise I'll try the PRO.

regards,

Conall

[This message has been edited by Conall (edited 11-16-2000).]

[Jeff Duquette]

Conall:

Here is the image you wanted. Thanks for contacting Dave F. Should be interesting to see what he can scrounge up.

M38 Stuart Optics (another image provided to me by Conall)

A footnote to my Stuart LOS quirk. I replayed the same “range test” except substituted Comets for the Stuarts. I got the same effect in that Comets could see and fire at the Tiger I, but the Tiger I was unable to see and fire at the Comets. Average range approx 1550 meters. The Comets showed up only as roundels. Technically not anything to do with accuracy or optics…simply a side effect noted during a test scenario.

Steve:

With regards to getting a show of hands on aspects of CM design…I personally am not interested in attempting to change the CM Engine. I don’t have a clue about what goes into computer wargame design. Maybe if I really had a clue I would get off my ass and go design a game of my own. My chief interest in this particular thread is discussing bits and pieces of WWII history. CM simply acts as the catalyst for such discussions. Playing Wargames without studying history is like eating French fries without Ketchup. Totally uncivilized behavior.

I personally think BTS has done a fine job with CM, and I get a big kick out of playing it. I think it’s an excellent model of WWII tactical combat given the constriants of hardware\software etc. and abstractions required in any wargame. I’m not seriously suggesting BTS model German tank crews who put leather covers over their optics.

What impresses me most about BTS is there good natured approach to discussing players bitches and moans. “How come the game isn’t more like the way I want it to be” seems to be paramount in many bitchie posts. Rather than some attempt to dig into the question (ala Paul, John and Machineman), we read one reference that implies “such and such” than we wield “reference such and such” like a sword…never going beyond the possibility that there may be other information that contradicts “reference such and such”.

Having said this I wanted to add that I have been a long time poster\lurker on several Close Combat forums (I know…I know…Close Combat is a heathens game). When game related disscussions arose on these forums ATOMIC’s reps (I wont mention any names…DW) always responded very rudely and defensively. The designers really turned me off about a game that I enjoyed. They are certainly entitled to say we are full of ****…just say it in a diplomatic manner.

I’m relatively new to this forum, but I am impressed with the tact that BTS tends to use in their responses to customer bellyaches and moans. Makes me feel like the money I have invested into CM is going to basically good folks (I shelled out for two copies…one for me…one for my brother...2nd I.D. Korea...has his own Tank Battalion now...urah big bro).

[This message has been edited by Jeff Duquette (edited 11-16-2000).]

[Guest Big Time Software]

Conall wrote:

<BLOCKQUOTE>quote:</font><HR>This is why I find the ability of the Stuart to spot a Tiger I @2000m-1500m without being spotted (see tests posted earlier) somewhat disturbing.<HR></BLOCKQUOTE>

Ah... but were the tanks unbuttoned? No tank commander would use his targeting optics for seeing what is out on the battlefield unless enemy fire compelled him to do so. The TC would use binocs (probably 10x plus easier to use) and the bare eye to direct the actions of the tank and turret so as to engage the enemy target. Then the gunner would use the optics that we have all been discussing to engage the enemy vehicle. So all discussions of spotting using optics from an unbuttoned tank is misplaced since it is irrelevant.

I will say this though... there is a bug in spotting model (or at least I think there is) for ranges over 2000m IIRC. It should affect all vehicles/units equally though, so I don't think this is cropping up as an issue here. I'll double check with Charles, but I believe this has been fixed for 1.1

Jeff, thanks for the further discussion and the heaps of praise. Customer support and feedback are what makes CM so great.

This is an interesting topic even if we don't feel the need to change the model. And who knows. Maybe there will be some changes made based on this discussion for CM2. So far I don't really see anything that we should change, but with all this info being dug out... you never know

Steve

[This message has been edited by Big Time Software (edited 11-17-2000).]

[Guest machineman]

I'll second Jeff's points. I use the forum as a place to chew over and learn about various WWII 'iron' (I do like machines, I do), and I come here because I find the info people bring up really interesting. If BTS choses to incorporate any of it in the game, then fine, but that is up to them. It's their game after all and as Steve keeps saying, they have to balance all the issues. It's always easier to back seat drive.

[Simon Fox]

<BLOCKQUOTE>quote:</font><HR>There is one story told somewhere about a 2 pdr AT gunner hitting a German armored car in the desert, at some ungodly long range which was beyond his sight reticle, like 2400 yards or more.<HR></BLOCKQUOTE>

On 23rd March 1941 British/Australian recon force operating west of El Agheila encountered a mixed German force of armoured cars, light tanks and trucks. In the ensuing engagment a 2pdr AT gun from the 16th Australian infantry anti-tank company under the command of a Cpl Kennedy knocked out at first two vehicles at 1000yds and finally 1 vehicle at 2,500yds. The 2pdr was only calibrated to 1,800 yds. Clearly for CM3 Australian AT gunners should have some positive modifier

<BLOCKQUOTE>quote:</font><HR>Robert makes the comment about ± 25% accuracy on range estimations for the Brits Vs ± 10%

for the germans.<HR></BLOCKQUOTE> I think the comment specifically referred to german Tiger gunners. Were Tiger gunners indicative of the 'average' german gunner?

In addition to the x3 sight posted for the 17pdr earlier I understand there was also a x6 sight as well. Any info on that?

On the subject of binoculars/spotting: you can rest assured that if allied tankers felt their binos were inadequate vis a vis the germans they would have rapidly acquired a pair. Try modelling that!

[Conall]

<BLOCKQUOTE>quote:</font><HR>Originally posted by Simon Fox:

In addition to the x3 sight posted for the 17pdr earlier I understand there was also a x6 sight as well. Any info on that?

<HR></BLOCKQUOTE>

There was a x6 optional eyepiece that could be fitted (not in thye heat of battle I suspect). It was the No.43 Mk 3 & Mk 3/1, which had a magnification of 3x with a FOV of 13 degrees or 6x with a FOV of 9 degrees (again Jeff may have the piccie). I suspect from anecdotal material that most gunners opted for the 6x scope despite the loss of FOV. Incidentally Firefly gunners/commanders were taught to blink at the moment of firing to prevent temporary blindness from the muzzle flash (made spotting fall of shot difficult).

regards,

Conall

[This message has been edited by Conall (edited 11-17-2000).]

[Paul Lakowski]

<BLOCKQUOTE>quote:</font><HR>Originally posted by Simon Fox:

Robert makes the comment about ± 25% accuracy on range estimations for the Brits Vs ± 10%

for the germans.<HR></BLOCKQUOTE> I think the comment specifically referred to german Tiger gunners. Were Tiger gunners indicative of the 'average' german gunner?

In addition to the x3 sight posted for the 17pdr earlier I understand there was also a x6 sight as well. Any info on that?

On the subject of binoculars/spotting: you can rest assured that if allied tankers felt their binos were inadequate vis a vis the germans they would have rapidly acquired a pair. Try modelling that!

Simon the point is that he thinks that it wasn't the stadimeteric system or the training asmuch as the quality of the lenses being superior...they were very clear and had big field of view. Thats why Robert makes the comment about the Sherman gunners being unable to identify who was shooting at them.

How do you quantify lens clarity and quality?

[Jeff Duquette]

Nothing really new here. Some Jentz info for the Panther.

I did find a photo in a study on the Jagdtiger depicting a pair of scissors type periscope protruding through the TC hatch (TSF1 spotting periscope presumably). The TC’s hatch had some sort of smaller hatch specifically for the TSF1 (TZF1) periscope to stick through. The periscope apparently had graduated lines or stadia lines. Range finding with this periscope was based upon a mil scale and range would be estimated similar to the Ziess site (i.e. the viewer needs to have some knowledge of the targets actual dimensions).

Apparently the Tiger Ie and Panthers A,D and G TC's hatches did not have the small hinged hatch for the TSF1. TSF1 would not have been "usable" while the TC was buttoned. The Panther F was apparently to have small TSF1 (TZF1) hatch: "The commander's cupola on the Schmalturm was lower, had a hinged hatch, and was drilled so that a TSF1 spotting periscope could be raised without opening the commander's hatch."

Panther Gun Accuracy 75mmL70 Pzgr39/42 Test (bold)…Practice (in parentheses)

500 meters 100 (100%)

1000 meters 100 (97%)

1500 meters 100 (72%)

2000 meters 92 (49%)

2500 meters 73 (29%)

3000 meters 55 (18%)

Jentz provides his favorite comments regarding the above figures:

<BLOCKQUOTE>quote:</font><HR>The 7,5 cm KwK42 L/70 was a very accurate gun capable of first round hits at ranges exceeding 1000 meters. The estimated accuracy is given as the probability (in percentage) of hitting a target 2 meters high and 2.5 meters wide, representing the target presented by the front of an opposing tank. These accuracy tables are based on the assumptions that the actual range to the target has been correctly determined and that the distribution of hits is centered on the aiming point. The Test data show the accuracy obtained during controlled test firing of the gun to determine the pattern of dispersion. The Practice data include the variation expected during practice firing due to differences between guns, ammunition, and gunners. Both data were reported in the accuracy tables from an original report on the 7,5 cm KwK42 L/70 as shown in the Accuracy table. These accuracy tables do not reflect the actual probability of hitting a target under battlefield conditions. Due to errors in estimating the range and many other factors, the probability of a first round hit was much lower than shown in these tables. However, the average, calm gunner, after sensing the tracer from the first round, could achieve the accuracy shown as the Practice data.<HR></BLOCKQUOTE>

Images of Panther Gunners Optics TzF12 and 12a. Very similar to the Tigers TzF9

[This message has been edited by Jeff Duquette (edited 11-18-2000).]

[Paul Lakowski]

You know its really great having an 'old man' whose both a Scientist and an Ophthalmologist, but when he's also crazy about lenses and was in the German army......

OK a short course in lenses....The function of a lens is to bring light rays into focus . A lens can be seen as a back to back prism that attempts to bend as little as possible while the light that passes through the lens. Concave lens result in 'barrel distortion' that tend to bend the rays towards the periphery while convex lenses tend to bend the rays towards the middle or 'pin distortion'.

But the distortion of light is different depending on where the light is chromatic or monochromatic,the best quality of lenses are those that deal with both these types of distortion.Depending on the quality of design, each lens in a series will lose 8-10% energy and while its possible to build multiple lenses by the time you hit half a dozen lenses you have great undistorted magnification but the human eye can't pick out much cause you've lost more than 1/2 the light energy. Any focusing device therefore becomes a series of lenses and a balancing act ,and you can imagine there's a very fine line in quality and the demands on production quality are very, very high.

OK a short History lesson. By the end of the 19th century [ 1890s] the design of choice for a focusing device was a 4 x element lens that was composed of back to back concave lenses sandwiched between two convex lenses . This generally resulted in a 28-35% 'loss of vision' but allowed the kind of magnification used on telescopes and guns sights etc etc. The Germans recognizing the importance of lenses were world leaders in the research and development of lenses and discovered that 'Lanthanum' in the glass improved the clarity of the lens, suggesting there figures on loss would be below the 30% level

.Just before WW-II in the late 30s they discovered that if you are able to deposit a thin layer of Argon gas on the lens this reduces the distortion per lens to around 3-4% ....no one else in the world could do this until well after the war. What this meant was that German lenses used in WW-II could successfully use 4-6 element lenses to achieve greater magnification with out distortion and a much less overall loss of vision [15-22%] and thus much larger clearer lenses for the same magnification or much greater magnification for the same field of view.

[Jeff Duquette]

Interesting Paul. I just found several WWII GI Tanker related tales regarding the mythical superiority of German Tank optics. I will post later.

A couple of interesting images from: “Panzer Page” by Eric Reits. URL: http://www.geocities.com/ereits/

I am guessing that this is the infamous TS1R or TZ1R spotting periscope...or the TSR1 was very similar in appearance to this scope. The photo is actually from a STUG III. Note the similarity in the device relative to the photo I posted of British Tanker Lt. Bill Cotton holding a captured German periscope (taken from either a destroyed MkIVh or MkVIe in Villers Boccage).

Another interesting image from the same web site

Flak 88 in an anti-tank role. Note the observer well to the left of the gun position outside potential flash and dust plume zone; Somewhat easier to observe his guns fall of shot from this position.

[This message has been edited by Jeff Duquette (edited 11-18-2000).]