Re: [PSUBS-MAILIST] spec qustions

[Coalbunny <coalbunny@vcn.com>]

What I am thinking right now is a half sphere welded onto the hull and
then make like a false shell similar to what the USN did during WW2. 
This would provide the opportunity to have a streamlines shape specific
for my needs.  If I go into a lake or ocean, I can use one type of false
shell and if I go into the rivers I can use a special one.
Carl


> "Dale A. Raby" wrote:
> 
> Well, I'll give you my half-cent worth on part of this.  Streamlining
> is streamlining regardless of size.  a "fish" shaped hull will give
> you (a) greater speed for the propulsive force applied, and (b)
> greater range of travel for the availble power/fuel supply.
> 
> How important these features are depends upon the intended purpose for
> the machine.  Navy subs are streamlined for both of the above
> reasons... as well as stealth, I believe, to some degree.  Their
> intended purpose is to go on long patrols where they may have to
> maintain speed with some very fast surface vessels, not to mention
> escaping from enemy vessels, so streamlining makes sense for them.
> 
> It might make sense for yours as well, though if speed is not a major
> concern and you don't intend to travel very far, other shapes might
> work just fine.  The sphere, I gather, makes the most sense as far as
> maximum crush depth is concerned, i.e.: the Trieste's passenger
> compartment and the old bathysphere design.  Spheres do not lend
> themselves well to streamlining, however.
> 
> Hull design is always a compromise between streamlining, and other
> factors.  WWII military subs had a veritable forest of antennae on
> their conning towers by the end of the war, which was very bad for
> streamlining, but they needed such things for command and control, so
> the forest was not harvested until after the war.  I belive that the
> Polaris class were the first really streamlined designs widely
> adapted, though the Hunley and the Holland designs were remarkably
> streamlined, considering that the concepts were not well understood at
> the time.  Bushnell's Turtle was not especially streamlined, but it
> didn't have to be, it only needed to travel a short distance to a ship
> at anchor in a harbor, attach a bomb and make an escape.  That it
> failed in its mission was not due to it's hull design, but rather the
> inability of the attachment screw to penetrate the copper sheathed
> hull of the enemy vessel.  In the case of the Hunley, with a spar
> torpedo that had to penetrate the hull and pull away detaching the
> spar, and given only human muscle power for propulsion, streamlining
> was quite important to attain the speed so that the spar would stay
> stuck in the hull of the target.
> 
> I've always thought that a teardrop shape might be the way to go as it
> is more or less a streamlined sphere.  The aft section would not even
> have to be pressurized, though it probably would need some kind of
> trim tank.
> 
> On Thu, 2003-01-09 at 06:20, Coalbunny wrote:
> 
> > In a sub that is designed for a working dpeth of no greater than 120
> > feet, I presume the designed crush depth would be no less than 240 feet,
> > correct?
> >
> > What would the proper alloy and diminsions of the ribs be?  I presume a
> > ring with the annulus of 6", 1/4" thick.  The external diameter of the
> > rib would be 5' and the internal diameter would be 4'.  Is this correct
> > or am I designing this wrong?
> >
> > Also, on a small sub, would it be beneficial to have a streamlined hull
> > like that on the USN SSBNs or because of the size, does it not matter?
> > My preference is using this in rivers, with some use in lakes and
> > possibly in salt water.
> > Carl
> >
> 
> 
> Dale A. Raby
> Editor/Publisher
> The Green Bay Web
> http://www.thegreenbayweb.com

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