Isigny Panther

[EKB]

FYI,

I found a photograph and source that might be of interest. Picture #4 is the full frame of photo #1 which I had posted in another thread. This appears to be the same tank as in photo #2 and #3 used for U.S. Army shooting trials in Normandy. The remarkable increase in size of the hole was caused by additional hits or delayed structural failure from previous hits. The man standing in front of the Panther is Dr. Erbes of 3rd Battalion / 67th Armored Regiment. No date on the image but it was probably made during the staging for Operation Cobra.

[Simon H]

The same Panther before it was modified;

[Avalancheon]

A few weeks ago, I found an interesting document about the performance of the 75mm M3 and 76mm M1 guns against German tanks. It mentioned the Isigny tests against the Panther. The authors extrapolate from all the available data in order to estimate the effective ranges against various aspects of the Tiger, Panther, and panzer IV. I was impressed to find that they used three different equations to make their range tables: The Lambert-Zukas, Thompson, and BAL65 equations.


THE 76-MM GUN M1A1 AND M1A2: AN ANALYSIS OF U.S. ANTI-TANK CAPABILITIES DURING WORLD WAR II

https://apps.dtic.mil/dtic/tr/fulltext/u2/1045347.pdf

[Mobius]

THE 76-MM GUN M1A1 AND M1A2: AN ANALYSIS OF U.S. ANTI-TANK CAPABILITIES DURING WORLD WAR II
https://apps.dtic.mil/dtic/tr/fulltext/u2/1045347.pdf

The researchers had to create the ballistic data of the 76mm HVAP? While they did this study at the Picatinny Arsenal, New Jersey, they did not find the July 1948 edition of TM 9-1907 which did have the ballistic graph of the M93 HVAP. The TM 9 1907 manual is not available at the dtic.mil site but N4636C is and that also includes the ballistic graph of 76mm T4E17 / T4E20 (M93).

[Richard Anderson]

It was also already discussed at length here viewtopic.php?p=2120742#p2120742

[Mobius]

The biggest mystery I think is how did they get funding to study US WWII tank guns vs tank armor in 2018? I could understand if World of Tanks funded it but the US Army?

[critical mass]

It looks to me like a M.A. or B.Sc./B.A. study, not exatcly sth in need of funding. I can ask Dr. Carlucci, though.

[Avalancheon]

One thing you don't usually consider in these situations is that armor vs weapons is a probability game. The authors use the Lambert-Zukas equation to calculate the V50 of the 76mm M62 APC shell against various tanks from various aspects. At the V50 range, 50% of shots will break up, and 50% of shots will penetrate.

If you're firing at a target from a range that exactly corresponds with the V50 of your shell, then your odds of actually punching through the armor are pretty poor. Statistically speaking, you'd need to fire alot more than 2 shots to guarantee a penetration.

[critical mass]

Most of the time, that´s at least my experience, we lack the necessary informations to approach this question from a frequentist perspective.
You need a huge and equal sample size.
F.e. the crit V/50 may be useful, but only in case You now the sample size for the data (and there will be individual datapoints with hundreds, even thousends of informations and other velocity / obliquity conditions which altogether are absent with zero data). Then You need not only the V/50 but also a measure of variance, such as the standart deviation -and that´s only if You presume the background distribution to be normal (that is unimodal and symmetrical).

Instead, I strongly prefer bayesian statistics. That allows You to include hinsight information (like actual datapoints from conflict assessment), it´s not constrained by the frequently too small sample size of datapool and it allows You to vary the unknown priors until Your posterior solution does closely match the observed data. Which in turn, tells You something about the likely and unlikely priors.

[Mobius]

I've saved this from another's post.

The USA method for determination of BL(N) would be to employ an “up and down” firing method until 3 complete penetrations (CP) and 3 partial penetrations (PP) are obtained within a velocity spread no greater than 100-fps (in some documents 120-fts). Or; If the zone of mixed PP and CP results is greater than 100-fps, “fire additional rounds to obtain a minimum of 3 CP and 3PP in the mixed zone. Or; If no mixed zone is obtained, average the velocities of the lowest CP and the highest PP. Or; If the mixed zone is less than 100-fps, average the velocities of the 3 lowest CPs and three highest PPs. Or; If there are an uneven number of PPs and CPs within the mixed zone, than one of two weighted averages is employed to determine the limit velocity. The first weight average applies if the number of PPs in the mixed zone exceeds the number of CPs in the mixed zone:

EQUATION 1
BL = VA + [((Np – Nc)/(Np + Nc)) x (Vhp – VA)

VA = Average of all velocities in the mixed zone
Np = the number of PPs in the mixed zone
Nc = the number of CPs in the mixed zone
Vhp = the velocity of the highest PP

The second weighted average applies if the number of CPs in the mixed zone exceeds the number of PPs in the mixed zone:

EQUATION 2
BL = VA - [((Nc – Np)/(Nc + Np)) x (VA – Vlc)

VA = Average of all velocities in the mixed zone
Np = the number of PPs in the mixed zone
Nc = the number of CPs in the mixed zone
Vlc = the velocity of the lowest CP

[Yoozername]

I believe there is video online of this test. It seems at close range also.

[Michael Kenny]

https://www.youtube.com/watch?v=QFQhFTq ... x=131&t=0s

[critical mass]

Anymore ideas about the details of these PANTHER firing trials? in particular terminal velocity and projectile type used?

[Yoozername]

Some notes:

It is very close range. If you look at the video, you can see a dust cloud (from the gun) after the projectile strike on the right side of the video.

It appears to me to be a M82 projectile. A M77 would not show the explosive effect (it is solid). Watch the video part that shows slow motion, and you can see the strike area (near the stenciled words), and a HE detonation higher up. Evidently exploding after a ricochet.

The armor did not crack. Even the welds, often times seen cracked and distorted, did not appear too damaged with a strike on them.

I believe there is another video of this also. I recall a incredulous person after the shoot.

[Michael Kenny]

This very trial was discussed extensively on Tank Net and there is a multi-page thread there with all these photos and many more.