Search found 797 matches

by Bill Jurens
Mon Sep 13, 2021 2:00 am
Forum: Naval Weapons
Topic: Questions regarding to the performance of German 20.3cm guns
Replies: 3
Views: 271

Re: Questions regarding to the performance of German 20.3cm guns

@ Cobralion. My thanks for posting these equations, but they are not of any practical use unless unless variables and units are specified, or unless one has ADM213/951 at hand, in which case the equations are actually redundant. It's nice to know, for example, that m = 0.5 +Bx, but not very handy un...
by Bill Jurens
Fri Sep 03, 2021 2:50 am
Forum: Bismarck General Discussion
Topic: The so-called "GKdos100"
Replies: 12
Views: 558

Re: The so-called "GKdos100"

Very nice work. Thank you Jose.

Bill Jurens
by Bill Jurens
Sun Aug 15, 2021 11:34 pm
Forum: Bismarck General Discussion
Topic: Sinking of the Hood- did all the magazines explode?
Replies: 28
Views: 1257

Re: Sinking of the Hood- did all the magazines explode?

Mr. Mercer wrote: "One thing that puzzles me is the implosion of a ship due to water pressure as it gets further down, I can understand why the stern of Titanic is completely wrecked as it presumably broke off near the surface and did not have anything to stop it spiraling down with water press...
by Bill Jurens
Fri Aug 13, 2021 3:33 am
Forum: Bismarck General Discussion
Topic: Sinking of the Hood- did all the magazines explode?
Replies: 28
Views: 1257

Re: Sinking of the Hood- did all the magazines explode?

There are certainly a number of cases where magazines have when large warships capsize. HMS Audacious and Barham are two good examples of this. These explosions seem to usually happen when the ship is still on, or very near, the surface. The probability of magazine explosions after the ship has subm...
by Bill Jurens
Mon Aug 09, 2021 6:13 pm
Forum: Bismarck General Discussion
Topic: Sinking of the Hood- did all the magazines explode?
Replies: 28
Views: 1257

Re: Sinking of the Hood- did all the magazines explode?

@ Paul Mercer: I am pretty sure that the turret explosion you referred to occurred on USS Iowa, not New Jersey. This sort of thing did not occur on Iowa, as the breech door was never closed in the first place, i.e. the explosion there occurred during the loading process itself. There are only a few ...
by Bill Jurens
Mon Aug 09, 2021 6:31 am
Forum: Bismarck General Discussion
Topic: Sinking of the Hood- did all the magazines explode?
Replies: 28
Views: 1257

Re: Sinking of the Hood- did all the magazines explode?

My thanks to those who have submitted comments on the so-called 'forward magazine explosion' hypothesis. The original formulation of this, was even more bizarre than the version(s) still in circulation, i.e. they claimed -- believe it or not -- that the forward magazine explosion not only took place...
by Bill Jurens
Sat Jul 24, 2021 3:08 pm
Forum: Bismarck General Discussion
Topic: Sinking of the Hood- did all the magazines explode?
Replies: 28
Views: 1257

Re: Sinking of the Hood- did all the magazines explode?

It appears that someone is still flogging that old ITN Channel 4 "documentary" on the loss of Hood, or something very similar. I noticed one recently, i.e. about five years ago, where a search team rediscovered -- with apparently some surprise -- that the rudder was actually over on the st...
by Bill Jurens
Wed Jul 21, 2021 3:26 am
Forum: Bismarck General Discussion
Topic: Paintwork Query
Replies: 17
Views: 657

Re: Paintwork Query

Thank you Jose: As I hardly ever read my own work, I frankly didn't notice. Using that information, I may be able to find out a bit more about precisely where that image was taken. The white material may -- and I have to emphasis the MAY -- be some sort of mold. There is a lot of that scattered at v...
by Bill Jurens
Mon Jul 19, 2021 9:42 pm
Forum: Bismarck General Discussion
Topic: Paintwork Query
Replies: 17
Views: 657

Re: Paintwork Query

It's almost impossible to decipher these sorts of things from a single image. (I can tell you from experience that it's often quite difficult even in real time to determine anything with a high degree of certainty. Do you have any other images in the sequence? Often, if you take two closely-spaced i...
by Bill Jurens
Thu Jun 24, 2021 11:36 pm
Forum: Movies, Films, Documentaries and Games
Topic: Atlantic Fleet battles
Replies: 4
Views: 788

Re: Atlantic Fleet battles

I would concur. The most mechanically meticulous effort I've ever seen was embodied in the Maneuver and Fire Rules. But they are very difficult to work through by hand -- although it IS possible to do so -- and, although there have been attempts to computerize them, at the time this was done, contem...
by Bill Jurens
Fri May 28, 2021 10:43 pm
Forum: Bismarck General Discussion
Topic: Famous picture showing Bismarck down by the bow
Replies: 9
Views: 677

Re: Famous picture showing Bismarck down by the bow

My own opinion is 'no'. There is some damage on the portside forward which appears as though some material might have been welded in place, and there are a few holes and damaged areas on the starboard side which may (or may not) correspond with an exit hole (or holes) close to what would have been t...
by Bill Jurens
Fri May 28, 2021 6:00 pm
Forum: Bismarck General Discussion
Topic: Famous picture showing Bismarck down by the bow
Replies: 9
Views: 677

Re: Famous picture showing Bismarck down by the bow

I just did a bit more photogrammetric work on the photo in question. If you take the horizon to be horizontal (a reasonable assumption given the sea conditions), you will find that the masts come out to all intents and purposes dead vertical, which would suggest the ship is hardly trimming at all. A...
by Bill Jurens
Fri May 28, 2021 5:13 pm
Forum: Bismarck General Discussion
Topic: Famous picture showing Bismarck down by the bow
Replies: 9
Views: 677

Re: Famous picture showing Bismarck down by the bow

I suspect that you are essentially correct. My feeling has always been that the photographer 'snapped' the photo when the ship was in one of its most extreme positions, i.e. one that was visually the most interesting, and that photos taken at random would not show nearly so much apparent trim by the...
by Bill Jurens
Thu Apr 22, 2021 8:46 pm
Forum: Bismarck General Discussion
Topic: Raumotters to the Rescue
Replies: 26
Views: 1295

Re: Raumotters to the Rescue

Trying to synchronize propeller thrusts, rudder forces (which were probably uncertain and variable depending upon how much rudder was actually there, etc.), wind forces, sea forces, and paravane thrusts (which would seem to be difficult to regulate with precision) would probably be impossible, espec...
by Bill Jurens
Mon Apr 19, 2021 2:44 am
Forum: Bismarck General Discussion
Topic: bismark-after torpedo hit
Replies: 203
Views: 15333

Re: bismark-after torpedo hit

I haven't done any calculations, but my suspicion is that paravanes even if streamed at speed would not be able to exert enough transverse force to make any significant difference. They were, after all, only intended to move minesweeping wires outboard and to support a fairly light cable to cut the ...