[PSUBS-MAILIST] Re: KEN MARTINDALE (was Big Motor..)

["Michael B. Holt" <mholt@richmond.edu>]

Captain Nemo wrote:
> I'd like that, thanks!  And I think it would be cool copyrightwise, because
> to my understanding, the reproduction of a small part (one page) of a book
> on a limited basis for the non-commercial and educational dissemination of
> information is acceptable under "fair use".

That's my understanding of the "fair use" idea.  I felt no qualms about
using the formula, with proper credit, in my work.  (All I did, from
my perspective, is translate Busby.)


> "(It did tell me that the Nautilus in the book would need 4400 HP to move at
> 15 knots.)"
> 
> Yow!  I haven't seen Busby's book, but that must be one BIG Nautilus: maybe
> the SSN 571?

I looked back in my annotated "20,000 Leagues Under the Sea," to get the
numbers Verne used.  In Prof. Aronnax's first private interview, 
Captain
Nemo privides all the number in metric.  That Nautilius displaced 1500
tons, was 228 feet long and cruised at 15 knots.  Quite a respectable 
psub.  
 
> "I'm working through a table-load of books about ship design, trying to use
> the classic formulae to determine horsepower.  So far I've tried four
> appraoches, on a spreadsheet, and the accuracy is not good.  I have two more
> formulae to test.  More, as it happens."
> 
> Yeah Mike, I see what you're saying.  For my purposes, I kind of bypassed
> this aspect of it.  My sub was an experiment to see if I could design and
> build one; and then I went off on an "ornamental tangent" making it look
> like the Disney Nautilus.  

You did a magnificent thing,m creating that boat.

> It was never intended for serious travel; if it
> worked at all that was good enough for me; and so figuring the exact
> performance relative to thrust and horsepower didn't seem necessary at the
> time.  

What I see in my exploration is that most smaller boats would not
benefit from too much mathmatics.  Five horsepower is quite enoough.
I suspect that some of them have much more horsepower than they can
absorb. 

> Plus, in the case of my boat, I think the many extreme variables in
> hull geometry would make the calculation process especially complicated and
> hard to do accurately.

I have three-views and sections of Disney's Nautilus.  It must be 
seen as a work of engineering art.  Working up the numbers on that
shape would be daunting.   Some day I'm going to print out the plans
onto parchment, 11x17, and frame it on the wall to my library.  (I'm
setting up, in a 1890 townhouse, a Vicotrian gentleman's residence.
To finish it properly, I'll need also a reproduction of the skull of 
Piltown Man.)

> (I mean, it's probably a matter of comparing motive
> power output, propellor efficiency, and resultant useable thrust; versus the
> size, shape, mass, displacement / buoyancy, and drag coefficients of the
> hull; and the unusually ostentatious exterior features of my hull would
> probably make that process extremely difficult to determine with any real
> accuracy.) 

That's exactly it.  I've just not been able to work out how to
relate the elements.  I'm hampered by training that conentrates on
accounting and computers, education that centers on the mind of man
and old textbooks which were not written a reference books.



Mike Holt