[Date Prev][Date Next] [Chronological] [Thread] [Top]
RE: [PSUBS-MAILIST] Welder with Vision

To: personal_submersibles@psubs.org
Subject: RE: [PSUBS-MAILIST] Welder with Vision
From: robertbatta@comcast.net
Date: Wed, 31 Dec 2003 15:12:13 +0000
Cc: Dewey Mason <drmason2001@yahoo.com>, personal_submersibles@psubs.org

Dewey,

Thats a really interesting concept, is this method used somewhere ?  NASA ?  It would be a lot easier to build, less metal work.  

The "grain silo" is what I was going for - my mistake for saying cone - I do not plan on using a cone, my earlier description was focused on the conning tower, I should have been more detailed.

Thanks,

Rob
> Rob,
> Have you considered a composite? Either FRP over or
> under steel, or a metal outer, monolithic concrete
> inner hull structure? Even a multi-faceted hemisphere
> would be stronger than a cone, I would think. With as
> many as 20-30 plates. Like the tops of grain silos are
> done. I have a friend in materials design at NASA, and
> he and I have discussed the possible merits of a metal
> outer, from lighter gage steel or aluminum, with an
> injected plastic liner, say 1-2" thick. The
> possibilities are many, and different hull materials
> might be easier to work with and considerably stronger
> than steel. 
> Dewey
> --- robertbatta@comcast.net wrote:
> > Alec,
> > 
> > Exactly what I was looking for - thank you for your
> > insight. 
> > 
> > Rob
> >  
> > > Rob,
> > > 
> > > When you think of basic shapes applied to pressure
> > vessels, what you
> > > might call a "desirability rating" in
> > best-to-worst sequence is as
> > > follows:
> > > 
> > > 1) Sphere
> > > 2) Cylinder
> > > 3) Cone
> > > 4) Flat surface
> > > 
> > > That is, a sphere is more efficient than a
> > cylinder, etc. Things like
> > > elliptical cylinders or elliptical endcaps would
> > fall somewhere in
> > > between. Of course you see all sorts of flat
> > surfaces or odd shapes on
> > > submarines from the outside, but I'm talking of
> > the pressure hull
> > > proper, on 1 ATM boats.
> > > 
> > > So I have two suggestions:
> > > 
> > > For the endcaps, the ideal would be hemispheres
> > instead of "flatter"
> > > cones. However if you find hemispheres of the
> > desired measurements to be
> > > non-standard and thus expensive (this happened to
> > me), then try for
> > > elliptical endcaps, which are still a better
> > approximation to a
> > > hemisphere than a cone is.
> > > 
> > > Second, you might consider two vertical cylinders
> > for the coning tower
> > > instead of a half pipe. The reason spheres and
> > cylinders are efficient
> > > at resisting pressure is because the forces
> > created on the surfaces are
> > > evenly distributed. There must be a more elegant
> > way to put it, but if
> > > you think of a sphere, the force on any point has
> > an identical opposing
> > > force on the opposite side. This is true of a
> > cylinder too, but it is
> > > NOT true of a half pipe. Plus, with the half pipe
> > you have the challenge
> > > of closing the ends, and especially of providing a
> > hatch seat, in what
> > > would be a curved surface. That is if you're
> > planning a hatch on top of
> > > the coning tower.
> > > 
> > > Hope that helps, and I apologize in advance if
> > I've stated things that
> > > might be too obvious.
> > > 
> > > Thanks,
> > > 
> > > Alec
> > > 
> > > 
> > > -----Original Message-----
> > > From: robertbatta@comcast.net
> > [mailto:robertbatta@comcast.net] 
> > > Sent: Tuesday, December 30, 2003 4:45 PM
> > > To: personal_submersibles@psubs.org
> > > Subject: Re: [PSUBS-MAILIST] Welder with Vision
> > > 
> > > Thijs,
> > > 
> > > That is the design I had in mind.  My last sub was
> > a single occupant in
> > > the prone position, I am looking to "upgrade".
> > > 
> > > I realize the design is complex, Im hoping to get
> > feed back from you all
> > > on this.  To answer your question, yes, this is
> > the design I had in
> > > mind, two occupants, one in front of the other. 
> > > 
> > > Thanks,
> > > 
> > > Rob
> > > 
> > > > Rob,
> > > > 
> > > > What you discribe makes me think of a Perry
> > Cubmarine (If you don't
> > > know
> > > > what that looks like have a Google image search
> > for "PERRY
> > > CUBMARINE".) A
> > > > design like that gives you the opportunity to
> > have 2 people sitting
> > > upright
> > > > in a small sub. I fear that it is complicated to
> > design (stresses!)
> > > and
> > > > build. Is this the concept you have in mind?
> > > > 
> > > > Geatings,
> > > > Thijs Struijs
> > > > The Netherlands
> > > > ----- Original Message -----
> > > > From: <robertbatta@comcast.net>
> > > > To: <personal_submersibles@psubs.org>
> > > > Cc: "Carsten Standfuss" <MerlinSub@t-online.de>;
> > > > <personal_submersibles@psubs.org>
> > > > Sent: Tuesday, December 30, 2003 8:59 PM
> > > > Subject: Re: [PSUBS-MAILIST] Welder with Vision
> > > > 
> > > > 
> > > > > Not as of yet, I will send them when complete,
> > I may even hand draw
> > > > something to get my questions answered.  I am in
> > the process of moving
> > > from
> > > > one home to another, once settled in, I plan on
> > building a cardboard
> > > mock up
> > > > to nail down the measurements.  The pressure
> > hull is nothing more than
> > > a
> > > > pipe with end caps (30 or 45 Degree Cones), the
> > pilot and passenger
> > > are in
> > > > the sitting position, their upper bodies and
> > head are in the conning
> > > tower.
> > > > >
> > > > > For the conning tower, I plan to cut in half a
> > length of pipe
> > > (smaller
> > > > diameter), and mate it to the main pressure hull
> > - am I making sense ?
> > > > >
> > > > > I plan on using pipe flanges for view ports -
> > here's my question:
> > > With
> > > > the forward end cap on the conning tower ( that
> > is cut in half or
> > > shaped to
> > > > match the surface of the pressure hull ) can I
> > mate a pipe flange to
> > > that -
> > > > given all the angles ?  Am I asking for a
> > fabrication nightmare ?
> > > > >
> > > > > Again, my little knowledge of metal works -
> > The end cap is already
> > > coned
> > > > and cut to match the pressure hull, is it
> > feasible to cut a hole in it
> > > to
> > > > accept the pipe flange for a forward view port ?
> > > > >
> > > > > Please keep in mind, this is conceptual, I
> > appreciate constructive
> > > > criticism.
> > > > >
> > > > > Thanks in advance.
> > > > >
> > > > > Rob
> > > > >
> > > > >
> > > > >
> > > > >
> > > > >
> > > > >
> > > > > > Is a DWG or DXF file available ?
> > > > > > Or a scan of the drawing as JPG ?
> > > > > > What kind of questions about the welds ?
> > > > > >
> > > > > > regards Carsten (Naval Architect)
> > > > > >
> > > > > > irox schrieb:
> > > > > > >
> > > > > > > Hi Rob,
> > > > > > >
> > > > > > > unforunately I can't recommend anybody to
> > review your design,
> > > but I do
> > > > > > > hold some of your concerns.   Mainly -
> > will people think we are
> > > nuts
> > > > when
> > > > > > > we ask professionals to review our
> > designs?
> > > > > > >
> > > > > > > Has anybody had/hired a professional
> > engineer (in the
> > 
> === message truncated ===
> 
> 
> __________________________________
> Do you Yahoo!?
> Find out what made the Top Yahoo! Searches of 2003
> http://search.yahoo.com/top2003
Follow-Ups:
- RE: [PSUBS-MAILIST] Welder with Vision
  - From: Dewey Mason <drmason2001@yahoo.com>
Prev by Date: RE: [PSUBS-MAILIST] Welder with Vision
Next by Date: RE: [PSUBS-MAILIST] Welder with Vision
Index(es):
- Chronological
- Thread