Panther Fibel Discussion of Range Estimation

[Mr. Tittles]

Rexford

Do you use the gun height in your battlesight calcs? The Panther and Tiger I and II all had a gun that was about 2 meters off the ground to begin with. StuGs and Jagdpanzer had lower guns and battlesight methods would work better with them.

[rexford]

While much has been said about the high accuracy range measurements possible with the T.F. 14 scissor scope, no real numbers have been put forth regarding the expected first round hit probabilities. So I sat down and cranked through the numbing numbers using trajectory analysis and German data for random scatter.

The following stats apply to the 75L48 and 75L70 guns firing APCBC rounds at a 2m high by 2.5m wide target, and look at the expected first round hit percentages at 2000m and 3000m under the following conditions:

1. scissor scope distance between lenses is either 90cm, 45cm and 30cm

2. random ammo scatter equals one or two times the German test data

3. practical errors posted by Daniel are used as average values from bell-shaped normal distribution curve: 48m at 2000m and 108m at 3000m for 90cm objective distance

4. range finding function assumed to work with non-horizontal arms, which is possible but has not been proven beyond a doubt (at least to this Doubting Thomas who probably will be proved wrong in short orfer)

Practical error at lens separation distances other than 90cm assumed to be proportional to 90cm divided by the lens distance.

The first round hit probabilities are predicted to be:

90cm Lens Distance

===================

75L48 APCBC

Single Scatter: 31% at 2000m, 6% at 3000m

Double Scatter: 13% at 2000m, 3% at 3000m

75L70 APCBC

Single Scatter: 58% at 2000m, 16% at 3000m

Double Scatter: 40% at 2000m, 10% at 3000m

45cm Lens Distance

===================

75L48 APCBC

Single Scatter: 19% at 2000m, 3% at 3000m

Double Scatter: 9% at 2000m, 2% at 3000m

75L70 APCBC

Single Scatter: 35% at 2000m, 8% at 3000m

Double Scatter: 27% at 2000m, 5% at 3000m

30cm Lens Distance

===================

75L48 APCBC

Single Scatter: 13% at 2000m, 2% at 3000m

Double Scatter: 7% at 2000m, 1% at 3000m

75L70 APCBC

Single Scatter: 24% at 2000m, 5% at 3000m

Double Scatter: 21% at 2000m, 4% at 3000m

Notes:

German publications suggest that twice the test scatter be used in calculations to model battlefield conditions.

It would be good at this point to find definitive information and a reference showing the ability of the scissor scope to measure range when the lens arms were not horizontal, which appears to be the case in most, if not all pictures depicting use of the T.F. 14 scissors.

The above hit estimates assume that the crew works like in a highly trained and precise manner , where the commander correctly and clearly tells the gunner which range setting to use and the gunner accurately sets the range and carefully aims the finely aligned gun.

Discussions on the AFV News site suggested that “errors” unrelated to range estimation or measurement might account for a good percentage of the misses, which would lower the theoretical hit probabilities presented earlier in this post.

Note to Mr. Tittles: regarding the previous discussion on another thread regarding whether rounds bouncing off the pavement would detonate, the Sherman 75mm used ricochet fire to bounce HE off the ground and have the HE detonate above troops in trenches. The HE fuze had to be set to delay to avoid near instantaneous bursting.

Since 88mm APCBC bursters will be set off by a 7mm plate, it isn’t that obvious that rounds bouncing off the street wouldn’t detonate.

[rexford]

Originally posted by danielh:

I found some interesting info in Schneider's "Panzertaktik"

In Tankerschool (end 1943) the crews had to fulfill the following:

1st Exercise:

Using HE on a target at unknown range but less than 1200 meters. Own tank stationary target stationary (size of AT-Gun)

Criterion to pass: 1 Hit out of 4 rounds

2nd Exercise:

HE on a target at range greater 1200m, six HE rounds authorized (target the same as in 1)

Criterion to pass: 1 Hit

3rd Exercise:

AT round on a (stationary, frontal) tank target at greater than 1200m. 4 rounds authorized

Criterion to pass: 1 Hit

4th Exercise:

AT round on a moving (ca. 20km/h) tank target across the field of vision at 800 - 1200m. 3 (!!!) rounds authorized

Time: 30 sec. Firing time, target moves 150 m

Criterion to pass: 1 Hit

Notice: No Examination on tanktarget stationary below 1200 m !! (Because a first round hit is almost certain)

The book also in detail describes the firing procedures. It notes that for armored targets at ranges less than 1200m no aquisition firing is made (bracketing and the like), but instead immediate fire for effect is done. It starts with a 200m addition to the estimated range. If the first round is over the target (Gunner observes tracer of the AP-round), then 200m are substracted. If the first round is short the aim-point is corrected, if the next is also short then the error is much greater and the target is at a range greater than 1200m, therefore bracketing has to be used (Aquisition firing).

During exercise, firing is normally directed by the commander, however out in the battle the Gunner will engage targets of it's own. As soon as a target is identified by the gunner, he immediately calls out "Panzer", takes aim, warns (Achtung!) the crew and fires.... This is done by the Gunner until the Commander overrides (He can actually order the Gunner after the calling out "Panzer" and "Achtung!"(before actual fire).

So the firing procedures were straight forward and flexible.

Further as a rule always an AP-round was loaded in the gun on entering the battle, and the range set at 800m or 1000m.

Greets

Daniel

There are some statements that may not be on the mark.

First round hits at ranges less than 1200m are not certain, especially with 75L48 and 50L60 using AP type ammo (APCBC or APC). Please explain the basis for the above conclusion.

Secondly, the Panther Fibel indicates that a 200m addition/subtraction is used for the second bracketting shot at targets over 1200m.

The Panther Fibel and Tiger Fibel clearly show that one estimates the range to the target, adds half the perceived height in mils time 100m to the initial range estimate, and uses that adjusted range with aim at target bottom for the FIRST shot.

[rexford]

Originally posted by Mr. Tittles:

Rexford

Do you use the gun height in your battlesight calcs? The Panther and Tiger I and II all had a gun that was about 2 meters off the ground to begin with. StuGs and Jagdpanzer had lower guns and battlesight methods would work better with them.

We looked into the gun elevation issue and it does not matter. We ran ALOT of trajectory programs to explore the idea, since dug-in ATG would really benefit, and the trajectory is the same along the line of fire regardless of elevation.

The Panther Fibel shows drawings where the trajectory is measured with regard to a line from the gun to the aim point, so gun height is not a consideration.

[rexford]

Originally posted by danielh:

Rexford,

I wrote in first post:

I don't see any error in my initial calculation of the "Nabelvisier" (aiming at the bottom then adding range to hit in the middle). From Pantherfibel:

Their the formula is (pg 22 of Pantherfibel):

Estimated range + Targetheight in Strich ( or mils) x 100 = Nabelvisier for Armor piercing rounds.

The Fibel also mentions that shot "climbs" only 1/2 Strich (or Mils) for every 100m range added on the ladder.

What do you think ?

Greets

Daniel

The Panther Fibel math seems to suggest that one half the perceived height times 100m is added to the initial range estimate to obtain the adjusted aim at the target mid-section. Tiger Fibel definitely shows the one-half the perceived height times 100m as the range estimate adjustment.

Page 22 in the Panther Fibel, an 8 mil high target at 500m results in an adjusted range setting of 500m + 400m = 900m. Zielhohe is the desired height of the round, which is halfway up the target height.

The Panther Fibel drawings on page 22 show the bottom of the T34 at 500m and top at 1300m, aim setting equals estimated range (500m) plus one half the perceived height (1/2 x 800m, for 400m). For 900m aim.

[ August 09, 2004, 08:07 AM: Message edited by: rexford ]

[Mr. Tittles]

http://www.deutscheoptik.com/rangefinderinstruction.htm

This is data for a coincidence type rangefinder. It is very similar to the ones used by German lt. flak and was found in a Tiger tank in North Afrika.

[Mr. Tittles]

SF as rangefinders;

No conclusive proof has been shown I will admit. The only thing that is certain is that they ARE rangefinders. Anectdotal evidence (StuG commanders adjusting them with a level) and long range shots (4Km by a Hornet on one case), shows that long ranges are being determined accurately.

I have reviewed most of my photographic sources and StuGs definetly had them as standard items. The fact that StuGs are artillerymen (usually) and the use of SF by arty units and FO WOULD know how to measure range makes me lean towards actual range measurement with them.

There seems to be evidence of a smaller size and a larger size also. A hand held model 6 x 30 and the larger 'tripod' type.

As far as a small percentage of people being able to use them, the US Army found that 70 % of existing trained gunners could use them. While they did not like this, it does show that it was not a minority.

[Mr. Tittles]

http://www.europa.com/~telscope/mil`ger#.txt

A good list of German 1944 optics. Tank sights, rangefinders, binos, etc

1029 Scherenfernrohr (Em) SF (Em)

1030 Scherenfernrohr 14 Z SF 14 Z

1031 Scherenfernrohr 14 Z mit Gitterplatte SF 14 m Gi

1032 Scherenfernrohr 14 Z mit Gitterplatte (mot einheiten) SF 14 m Gi (mot E)

[Mr. Tittles]

Originally posted by rexford:

Note to Mr. Tittles: regarding the previous discussion on another thread regarding whether rounds bouncing off the pavement would detonate, the Sherman 75mm used ricochet fire to bounce HE off the ground and have the HE detonate above troops in trenches. The HE fuze had to be set to delay to avoid near instantaneous bursting.

Since 88mm APCBC bursters will be set off by a 7mm plate, it isn’t that obvious that rounds bouncing off the street wouldn’t detonate.

Uh yeah, it was discussed there. maybe you should go back to that thread and catch up.

[Mr. Tittles]

Heres an example of a rangefinder (coincidence type) that was found in early Tigers in North Afrika.

The later Tigers had the improved copula that had a mount for a scissors scope.

[danielh]

Rexford,

Thx, for the hit prob. for the 75/L48 & L75/70 when using SF-Sight !

To the discrepancies of Schneider's "Panzertaktik" in Training- and Battle- Drills to the ones described in the Panther- and Tiger-fibel i don't know.

To the examination excercises: I assume that atleast less than 3 rounds were needed for stationary targets below 1000m because the crew had to hit a moving tanktarget at 800-1200m within 30sec. and 3 shots. I also expect that a good crew would need less than 3 shots for the moving target, and even less for a stationary one (tank). Of course this is no "hard" evidence, but none the less logical.

Greets

Daniel

[ August 09, 2004, 02:04 PM: Message edited by: danielh ]

[rexford]

Originally posted by Mr. Tittles:

Heres an example of a rangefinder (coincidence type) that was found in early Tigers in North Afrika.

The later Tigers had the improved copula that had a mount for a scissors scope.

We have a coincidence rangefinder at work which I keep in my overhead cabinet. Every once in a while I take it out and use it, and the results are not that bad.

We also have laser rangefinder nocs which are easier to use, effective range out to 1200 yards. They are able to remove the irregular effects of rain drops and the like from the results, and tell you how good the quality of the target reflection is.

[rexford]

Originally posted by danielh:

Rexford,

Thx, for the hit prob. for the 75/L48 & L75/70 when using SF-Sight !

To the discrepancies of Schneider's "Panzertaktik" in Training- and Battle- Drills to the ones described in the Panther- and Tiger-fibel i don't know.

To the examination excercises: I assume that atleast less than 3 rounds were needed for stationary targets below 1000m because the crew had to hit a moving tanktarget at 800-1200m within 30sec. and 3 shots. I also expect that a good crew would need less than 3 shots for the moving target, and even less for a stationary one (tank). Of course this is no "hard" evidence, but none the less logical.

Greets

Daniel

If a target is at exactly 1000m and the triangles are used, assuming 3m height or 3m width, the height comparison will result in an overestimate of the range (very few real combat targets will show up as 3m in height) and using the width will result in an underestimate of the range (some tanks exceed 3m width.

If the target hull is angled by as little as 10 degrees to the firer, the effective frontal view width of a tank with a frontal width of 3m and side length of 6m increases to 4.0m, 33% wider than the actual frontal width. So a 10 degree target hull angle to a panzer results in a 25% underestimate of the effective range.

If a T34 is expected to look 3 mils wide at 1000m on a frontal view, then a 4 mil wide view of the enemy tank front width suggests a range of 750m (1000m x 3 mils/4 mils). Target looks 25% closer than actual.

The above explains why triangles do not result in a very high hit percentage at all ranges to 1200m.

[rexford]

Does anyone have a picture of a scissors scope that is good enough to estimate the distance between the objective lenses? Maybe by comparison with a soldiers head size or some other odd dimension that can be estimated reasonably well (I have a big fat head so won't use mine as a standard). )

I calculated three hit percentages with the T.F. 14 (90cm, 45cm and 30cm separation) to allow a curve to be drawn which would allow hit % estimates for lens separation inbetween the three points or slightly outside the outer points.

[rexford]

Originally posted by Mr. Tittles:

</font><blockquote>quote:</font><hr />Originally posted by rexford:

Note to Mr. Tittles: regarding the previous discussion on another thread regarding whether rounds bouncing off the pavement would detonate, the Sherman 75mm used ricochet fire to bounce HE off the ground and have the HE detonate above troops in trenches. The HE fuze had to be set to delay to avoid near instantaneous bursting.

Since 88mm APCBC bursters will be set off by a 7mm plate, it isn’t that obvious that rounds bouncing off the street wouldn’t detonate.

Uh yeah, it was discussed there. maybe you should go back to that thread and catch up. </font>

[Mr. Tittles]

It was addressed very well, you just don't understand it very well. Perhaps it has nothing to do with this thread, which is my point now. If you will go to the other thread and restate your question there, I will again explain to you the same thing as before. I have also uncovered new info regarding 90mm fuzes for AP.

Also...

I don't think you quite grasped what I was getting at when I wondered about the wierd German habit of needing to add onto range. Did any other WWII participent do anything like this?

The fact is, that there is no real way to field zero a AP type weapon to land exactly at a range.

[ August 09, 2004, 03:22 PM: Message edited by: Mr. Tittles ]

[rexford]

Originally posted by Mr. Tittles:

http://home.arcor.de/thuernagel/sf14-e.htm

I read through the above web site and there is one interesting comparison of the SF 14 site at two different positions, with arms near horizontal and the other with arms close to vertical.

Ready.

When the arms are close to vertical it is referred to as the "Periscopic mode". When the arms are almost horizontal it is referred to as the "stereoscopic mode".

This suggests to me that horizontal might be for range measurements via stereoscopic use, and vertical is limited to use as a periscope.

ALL of the pictures that are captioned as "stereoscopic mode" show the arms close to horizontal, and none of the pics with the arms close to vertical indicate stereoscopic mode.

The initial write-up for the web site piece states that the SF 14 could be adjusted either for periscopic or stereoscopic use.

This seems to raise a few questions regarding the use of the SF 14 when the arms were raised up through the top of a vehicle or up and over the shield on a Nashorn.

[Mr. Tittles]

http://home.arcor.de/thuernagel/sf14.htm

Same site in German. I believe the author is German? In any case, he mentions there is no manual included. I would be very impressed by some manual for this device. In other words, the author of that website does not know exactly how to use the device. From the description, it does not sound like this piece of equipment even works.

[ August 09, 2004, 03:47 PM: Message edited by: Mr. Tittles ]

[Mr. Tittles]

http://home.arcor.de/thuernagel/sdn.htm

Interesting cross sectional view

[Mr. Tittles]

http://www.eugeneleeslover.com/USNAVY/CHAPTER-16-F.html

good tutorial on rangefinders

[c3k]

Gents,

Why the Germans added to the range estimate: (Note that this is MY OPINION.) Obviously, when targeting an enemy, clear visibility is highly prized. Any kind of reticle would obscure a target. (At 1,000 meters, how wide would the lines of a the German targeting triangles appear?) To keep the target highly visible, AND to utilize a POINT target, the tip of the center triangle would be nice to use. To keep the tip from obscuring the aimpoint, the technique of putting the triangle point at the base of the target and adding to the range estimate (so the shell strikes ABOVE the triangle tip) would be a useful technique.

Thanks,

Ken

[flamingknives]

For what it's worth, putting the tip of the foresight below the target was how I was taught to use iron sights.

[rexford]

In an earlier post I asked about an explanation of how a stereoscopic rangefinder worked, and no answer was forthcoming. The following site lays out the basics of coincidence and stereoscopic rangefinding, which suggest that the TF 14 would not find ranges in the periscope position:

http://www.eugeneleeslover.com

Go to the Gene's U.S. Navy link and then volume 2 of naval ordnance and gunnery. Chapter 16 is what you want to look at, radar and optics.

Rangefinders work by measuring the angle needed to bring the view into a desired position, and the rotating range scale that one uses to adjust the view is tied into the distance between the lenses when they are horizontal.

See the bottom of the paragraph to the immediate left of figure 16F8 for an explanation of stereoscopic rangefinder adjustment and what it is actually doing:

"The operator adjusts the line of sight until the reticle image appears to lie at the same distance as the target image. The rangefinder has then measured the angle, and its scale indicates the range."

So, if the range finder is near vertical the distance between lenses is not consistent with the turnable range scale, and the range finder will NOT correctly read or determine range. The determination of the range to the target is a trigonometric function of base length and angle, and if the base length is not the same as the horizontal arms condition the range scale is not going to work.

Since the stereoscopic rangefinder works by measuring the horizontal angle needed to bring the view into compliance, if the arms are close to vertical they no longer are measuring horizontal angles when the range is adjusted. Another point to consider.

Scaling off pictures of the TF 14 rangefinder/periscope, the distance between the center of the two lenses appears to be 24.8cm, which seems further than the distance one obtains by scaling off the picture of the SF 14 protruding above the JagdTiger superstructure top.

With a base length of less than 25cm, the TF 14 would NOT provide the precise range measurements needed for a high percentage of first round hits at long range with the 128mm gun, or even the 88L71, even if it did work in periscope position.

Now we have two sites that suggest that the TF 14 will not measure ranges in the near vertical position.

Based on what I've seen, my view is that a near vertical TF 14 or SF 14 is not going to measure any ranges. Until someone brings up something to the contrary.

p.s. I posted this just prior to seeing Mr. Tittles post with the same web site as noted above. We both came upon the same stuff at the same time.

[ August 11, 2004, 01:44 PM: Message edited by: rexford ]

[rexford]

If a 2.4m T34 is at 800m range and a StuG IIIG estimates the range as 800m, the following range would be set on the gun:

800m initial range estimate

target appears to be 3 mils high so add 3 x 1/2 x 100m or 150m to the range estimate, for 950m.

Place triangle on target bottom but raise gun for 950m distance.

Trajectory of shot places round 1.28m above target bottom at 800m range, close to middle of target (Elvira's navel).

Tiger spots 2.4m high T34 at 1000m and estimates range as 1000m. T34 appears to be 2.4 mils high, so adjustment to range estimate equals 2.4 x 1/2 x 100m or 120m. Set gun for 1120m shot with triangles at bottom of target.

Trajectory places round 1.17m above target bottom at 1000m range, right around the target mid-point.

Panther spots 2.4m high T34 at 600m, estimates range as 600m. T34 appears to be 4 mils high, so range adjustment is 4 x 1/2 x 100m or 200m.

When gun is elevated for 800m shot at bottom of target round lands 0.8m above target bottom, a little low.

If Panther crew range estimate of 600m was adjusted by perceived height of T34 times 100m, result would be 600m + 4 x 100m or 1000m.

75L70 aimed at 1000m range and bottom of target places round 1.6m above target bottom at 600m.

I have read where the Germans aimed for the turret ring on KV and T34 tanks for disabling hits with light guns (even 37mm peashooters on 38t's could do it!), and 37mm Pak gunners were given pamphlets showing the vulnerable locations on the T34 front aspect which could be aimed at.

So it appears that the triangles were not always placed on the target bottom with the hope that a hit would occur anywhere on the target.

[Redwolf]

If anybody wants to buy scissor binoculars to play with them, some dude at the MIT tech flea market had two for sale the last times I have been there.

They were Russian, but looked exactly like the WW2 German models.

I made photos in case anyone wants to see them.