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by Bill Jurens
Mon Jan 29, 2024 9:05 pm
Forum: Hypothetical Naval Scenarios
Topic: Redesigning Bismarck
Replies: 45
Views: 31517

Re: Redesigning Bismarck

I take it you are referring to the capacity to provide steam for 'hotel' services in addition to that used for propulsion. That's a tough one to answer as these services represent a variable --and sometimes ill-defined -- load which can, in combat, often be diverted to propulsion, e.g. there is no n...
by Bill Jurens
Sat Jan 27, 2024 2:49 am
Forum: Naval Propulsion
Topic: Asymmetric Propellers
Replies: 9
Views: 12915

Re: Asymmetric Propellers

The terminology can be confusing. Usually, an asymmetric propeller is considered to be one that has blades of different sizes and shapes. The ultimate example is a one-bladed propeller, essentially a two-bladed propeller with one blade cut off and the hub somewhat reworked and counter-balanced so as...
by Bill Jurens
Sat Jan 27, 2024 1:43 am
Forum: Hypothetical Naval Scenarios
Topic: Redesigning Bismarck
Replies: 45
Views: 31517

Re: Redesigning Bismarck

Further to the earlier question, I am not sure exactly what might have been meant by the oil purification system either. It could be that Langsdorff felt that many fuel oil tanks had been contaminated with salt water due to leakages caused by near-misses during the action. The same might be said bec...
by Bill Jurens
Sat Jan 27, 2024 1:33 am
Forum: Hypothetical Naval Scenarios
Topic: Redesigning Bismarck
Replies: 45
Views: 31517

Re: Redesigning Bismarck

The best bet in this case would be to read a copy of my paper in Warship. My general sense of it is that this purified-oil problem has been somewhat over-emphasized. In reality, none of the damage details would have mattered very much; with the whole Royal Navy on the job, there was essentially no w...
by Bill Jurens
Thu Jan 25, 2024 8:00 pm
Forum: Hypothetical Naval Scenarios
Topic: Redesigning Bismarck
Replies: 45
Views: 31517

Re: Redesigning Bismarck

Alan Zimm and I did a very comprehensive treatment of the damage to Graf Spee in Warship 2018. His part was a tactical analysis. My part, "Under the Guns" was a technical analysis of the damage.

Bill Jurens
by Bill Jurens
Sun Jan 21, 2024 2:13 am
Forum: Bismarck General Discussion
Topic: closing up bismarck during daylight action
Replies: 10
Views: 2513

Re: closing up bismarck during daylight action

It appears that for whatever reasons, nobody is interested in tackling this. While I am not certain of the precise details of the portholes themselves -- i.e. I am not in the least suggesting I'm any kind of expert on the subject -- my suspicion would be that while at sea in wartime the metal extern...
by Bill Jurens
Fri Jan 12, 2024 5:28 pm
Forum: Bismarck General Discussion
Topic: 3-shaft propulsion
Replies: 128
Views: 91387

Re: 3-shaft propulsion

In a very general sense, one larger propeller turning slowly will be more efficient than any larger number of propellers turning more rapidly. The optimum number of propellers, and their size, is largely driven by issues of geometry -- draft is limited after all -- and the perceived need for redunda...
by Bill Jurens
Sat Jan 06, 2024 10:03 pm
Forum: Hypothetical Naval Scenarios
Topic: Redesigning Bismarck
Replies: 45
Views: 31517

Re: Redesigning Bismarck

Dunmunro wrote: "We have the example of USS Intrepid (Essex class carrier) being able to steer with her props after a jammed rudder via a torpedo hit..." Yes. I'm aware of cases like this, which is why I qualified my statements, e.g. "'...In general, it's impossible, or nearly so ...&...
by Bill Jurens
Fri Jan 05, 2024 4:40 am
Forum: Hypothetical Naval Scenarios
Topic: Redesigning Bismarck
Replies: 45
Views: 31517

Re: Redesigning Bismarck

Regarding steering issues, two main principles apply: a) In general it's impossible, or nearly so, to 'steer' with propellers only as to do so would require constant 'riding' of the propeller speeds etc. in order to adjust to slight variations in wind and wave. In the same way that one typically has...
by Bill Jurens
Thu Dec 07, 2023 3:57 am
Forum: Bismarck General Discussion
Topic: Bismarck and European battleships vs.US battleships - hull shape and seakeeping qualities.
Replies: 32
Views: 59031

Re: Bismarck and European battleships vs.US battleships - hull shape and seakeeping qualities.

As a start, I'd begin by examining the curve of sectional areas of each design, plus the movement of the longitudinal center of buoyancy with changes in displacement, plus the initial values, and changes in the longitudinal moment of inertia of the waterplane area. This is stuff that is perfectly ro...
by Bill Jurens
Tue Dec 05, 2023 6:53 pm
Forum: Bismarck General Discussion
Topic: Secundary guns turrets
Replies: 26
Views: 24145

Re: Secundary guns turrets

Re the Arizona explosion, I wrote one of a series of very detailed articles -- my recollection is there were three in the series -- on this particular subject. i.e. the mechanics of the explosion about fifteen years ago, published in Warship International. You should be able to find them in the Wars...
by Bill Jurens
Mon Dec 04, 2023 6:20 pm
Forum: Bismarck General Discussion
Topic: Secundary guns turrets
Replies: 26
Views: 24145

Re: Secundary guns turrets

There is some variance regarding the number of charges that might be ignited at any particular time, the type of propellant being used, the enclosed volume of the handling (note, in the RN this was 'handing') room, and the venting of the space -- accidental or otherwise -- vary from case to case, bu...
by Bill Jurens
Wed Nov 01, 2023 7:41 pm
Forum: Hypothetical Naval Scenarios
Topic: Fast Battleship League Table
Replies: 169
Views: 79022

Re: Fast Battleship League Table

Frank Simon wrote: If I recall correctly, you also intended to write a follow up on "Common Ground on Shifting Sands", or am I mistaken? No. You are correct. It's being written as an aid to predicting armor penetration, tentatively called "Predicting the Past". I would expect it ...
by Bill Jurens
Tue Oct 31, 2023 5:14 pm
Forum: Hypothetical Naval Scenarios
Topic: Fast Battleship League Table
Replies: 169
Views: 79022

Re: Fast Battleship League Table

My thanks for this information, which must have taken some time to compile. It does help to indicate where fact fades into supposition, e.g. regarding the number of guns in salvo, lie. Your observation regarding dispersion vs range is basically correct; at short ranges most dispersion is due to vari...
by Bill Jurens
Tue Oct 31, 2023 5:31 am
Forum: Hypothetical Naval Scenarios
Topic: Fast Battleship League Table
Replies: 169
Views: 79022

Re: Fast Battleship League Table

To Mr. Simon: You are certainly employing an interesting analysis procedure here, but without -- at least so far as I know -- revealing any data about exactly how some of your input values, e.g. true mean dispersions, were derived. Along similar lines, your computations for range error due to rangef...