German WWI Armor Piercing Shells?

[Ulrich Rudofsky]

Here is a known sample: A 16 inch US super-heavy shell and a 5'11.5" person; 2700 lbs vs 212 lbs
It is very difficult to measure and extrapolate the shells on the WW1 photo, but you can use me for target practice.

[marty1]

Is that a Detroit Tigers Hat your wearing Ulrich? You're not really a Tigers fan are you?

That's a big bomb. I think I'd dislike being on the receiving side of one of those things.

[marty1]

I disagree, the shell base is more or less in line with his toes so he's in line or a little behind the nearest one.

Unless he's a giant, the fact that the one nearest him comes to his waist makes it about 40-in tall unless he's very, very tall. So it's either 30.5-cm APC or 28-cm Spgr. The caps on the APC in the background are very apparent, the ones in the foreground clearly don't appear to have them so that suggests they must be Spgr. You should also be able to scale both the man and the shell fairly accurately from the rifle, again unless he's a giant it's a carbine (43-in) not a rifle (49-in) and it's a little longer than the shell so the answer is the same.

Mike

Hi Mike:

You could be right. It's tough for me to tell. I don't have any Wk1 German Naval 280mm psgr or spgr images or drawings to go off of. What I have are two scale drawings of German 305mm psgr and spgr from J.Campbells work on Jutland. See attached.

I am of the opinion that 280mm psgr and spgr (and 380mm for that matter) are simply scaled down (or scaled up) versions of the 305mm shells. But I don't know this for certain, and would therefore like to find images or better scale drawings of 280mm psgr. I am interested in accurate information on WK1 280mm psgr and spgr projectile length, nose geometry, and driving band diameters.

Best Regards
marty

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[Ulrich Rudofsky]

Is that a Detroit Tigers Hat your wearing Ulrich? You're not really a Tigers fan are you? .

Sorry to disappoint you. It's the US Rowing Association: I row a single and double scull.........

[mike1880]

I am of the opinion that 280mm psgr and spgr (and 380mm for that matter) are simply scaled down (or scaled up) versions of the 305mm shells. But I don't know this for certain, and would therefore like to find images or better scale drawings of 280mm psgr. I am interested in accurate information on WK1 280mm psgr and spgr projectile length, nose geometry, and driving band diameters.

Not exactly scaled down, they're slightly different lengths (3.2 cals vs. 3.4). Sounds as though you want to feed it to mcdrag?

I don't know of any detailed diagrams though (and I've found that a lot of what look like scale drawing aren't). IIRC there's a diagram early in GKDOS of 4 APC shells from various periods which gives an ogive radius for whatever calibre it is (I would guess they're all 28-cm because that's the only calibre that was in continuous service, but it is only a guess). But apart from that I don't think I've seen anything more detailed than the Campbell diagram.

Have you got driving band diameter for ANY shell of this period?

Mike

[marty1]

Not exactly scaled down, they're slightly different lengths (3.2 cals vs. 3.4). Sounds as though you want to feed it to mcdrag?

I have played with it, but no. I develop specific Cd curves based upon projectile shape and pressure distribution around the projectile as various speeds. It's a bit more reliable than trying to guess at form factors and drag functions. May I ask where you are deriving the 3.2-cal vs. 3.4-cal information from?

I don't know of any detailed diagrams though (and I've found that a lot of what look like scale drawing aren't). IIRC there's a diagram early in GKDOS of 4 APC shells from various periods which gives an ogive radius for whatever calibre it is (I would guess they're all 28-cm because that's the only calibre that was in continuous service, but it is only a guess). But apart from that I don't think I've seen anything more detailed than the Campbell diagram.

Have you got driving band diameter for ANY shell of this period?

Mike

Yes I've seen the KDOS drawings. These appear to be generic shapes, thus my theory that 11" psgr was simply a scaled-down version of 12" psgr.

I have driving band diameter information for most of the large caliber RN projectiles of the period. An additional source of drag. Equally important is actual projectile diameter vs. nominal diameter.

Best Regards
marty

[mike1880]

I develop specific Cd curves based upon projectile shape and pressure distribution around the projectile as various speeds. It's a bit more reliable than trying to guess at form factors and drag functions. May I ask where you are deriving the 3.2-cal vs. 3.4-cal information from?

It sounds like a challenge finding enough info on projectiles from this period. I'd be interested in hearing more about the methodolgy though, it's obviously more modern than anything than I've used. But do the results outweigh the extra effort involved in finding orders of magnitude more data?

I originally got 3.2 vs 3.4 from Facehard itself, but the basis for the list there is probably US Naval Technical Mission in Europe Report 393-45: "Service Major Caliber Projectiles of the German Navy" (which is little more than a list of names unfortunately).

Mike

[mike1880]

From the above mentioned report: "Restricted letter from US Technical Mission in Europe to CNO (OP-16-PT) of 27 August 1945, serial 850, forwarded blueprints of starred projectiles shown in Fig. 1". The the 28cm L3.2 is marked with an asterisk so there are (were) blueprints in the US archives...

Mike

[marty1]

It sounds like a challenge finding enough info on projectiles from this period. I'd be interested in hearing more about the methodolgy though, it's obviously more modern than anything than I've used. But do the results outweigh the extra effort involved in finding orders of magnitude more data?
Mike

Hi Mike

I've actually been able to find very good information from UK Archives on RN shells of the period. It's possible there is similar information out there on German Naval Projectiles of the Period. I'm in it for the long haul. It may take awhile to track down this sort of thing. Course by that time I may have tracked down schusstafeln and will not need detailed shell information But I've already tracked down decent information and scale drawings on German WWI Naval 280mm spgr. Now I just need to find psgr.

Regarding the extra effort -- it is a subject of interest to me, so it's less an effort more like dinking around with a hobby.

Best Regards
marty