Re: [PSUBS-MAILIST] Through Hull Connections

[Ian Roxborough <irox@ix.netcom.com>]

Hi,

I would be exercise caution with the wireless network inside the
hull.  I don't believe the radio waves from the wireless network
would penetrate the metal hull (or the water if you have s non-metal
hull).  Most of the radio waves will probably bounce around the
inside of the hull until the tx/rx equipment gets overloaded and
fails (maybe minor fire risk in the failure).  You will absorbe
some other radio wave energy bouncing around the inside of the hull
(not sure if this is going to be very healthy for you).

I would consider placing a wireless network antenna outside the
hull, on the p-scope say, so I could have a high bandwidth link
to a support vessel (somebody with a wireless laptop in a boat)
when on the surface.

I've always wonder what would happen if you put a small radar on
top of the p-scope and turned it on when under water...

As far as networks and computers go, it's going to be a good idea
to have heavy redundancy.  I was thinking of having the availity
of running all major systems off a water proofed PalmPilot if
everything fails

Ian.

On Thu, 01 May 2003 15:50:47 +1000
mckellar@earthlink.net wrote:

> Excellent (opto-electronics), thx :)
> 
> I had already decided to keep as much as possible outside the hull - 
> especially since reading the posts about batteries exploding/starting fires 
> inside the hull.
> 
> Obviously I will need some power inside the hull, but I should be able to 
> keep the demand fairly low.  The thing that concerns me the most is the 
> requirement for over 100hrs life support.  without something to pump air 
> over the scrubber and monitor and control essential systems, any other 
> 'failsafes' (eg lots of air/oxygen) become next to useless.  do i put a 
> bicycle type driven fan or generator on-board? (i jest, but it has some merit).
> 
> Which brings me to another question.  I'm assuming with joystick control, 
> various sensors, cameras etc more than one computer is really required for 
> control etc.  Is the solution to make everything dumb except the laptop/PC 
> or do you run a lan?  if a lan, wireless or cabled?
> 
> If cabled to things outside the hull, the same sealing problems occur.  if 
> wireless, that avoids thru hull connections, but how far is the signal 
> likely to transmit through saltwater (given that different manufacturers r 
> likely to have different broadcast strengths)?  then of course i have 
> to   have a client out-board to control thrusters, trim etc 
> <sigh>.  <warning: hopelessness and despondency follow :) > so many 
> problems at every turn :(  my speadsheet with specs is huge and still 
> nothing I'm really happy with.  The AutoCad 2000 solid modelling im 
> dabbling with is like a kids scribble :(
> 
> cheers
> peter
> 
> At 08:29 4/30/03 -0700, you wrote:
> >So I guess this begs the question of how the submersibles that actually do use
> >an acrlic sphere pass wires and the like. Do they drill holes and have plates
> >through bolted? I know some have spheres that are clamped together, and likely
> >everything is inside with no penetrations. Peter, how about using the 
> >sphere for
> >the human occupancy part only, and have the batteries, motors, etc. 
> >outside. You
> >could have optoelectronic controls which wouldn't need any holes.
> >
> >This is a good question for Phil, or someone really in the know.
> >
> >Jeff
> >
> >Quoting mckellar@earthlink.net:
> >
> > > Hi Warren and Dan,
> > >
> > > d@mn!! - this half-hearted attempt at self-censorship is a major concession
> > >
> > > - im aussie and the expletives flow naturally :)
> > >
> > > I really had my heart set on acrylic, even recognising that some components
> > >
> > > would likely end up metal :(  my 'ABSOLUTELY MUST BE' generally gets warped
> > >
> > > so much its bears no similarity to the original intent :)
> > >
> > > but, back to the ridiculous and unreasonable - could induction be used to
> > > pass a current thru the hull without the heat buildup issues?
> > >
> > > the differential expansion problem seems equally intractable :(  Even more
> > > so than the problem of hull penetration.  I had considered imbedding  some
> > > components permanently in the hull, despite the replacement and upgrade
> > > considerations, im going to have to think this one thru too :( -
> > > suggestions welcomed :)
> > >
> > > all assistance appreciated
> > > peter
> > >
> > >
> > >
> > >
> > > At 18:05 4/29/03 -0700, you wrote:
> > > >Be careful with acrylic. A metalic onject embedded in
> > > >acrylic with shrink and expand at a different rate,
> > > >and that can cause acrylic to fail explosively (when
> > > >under pressure).
> > > >
> > > >Warren.
> > >
> > >
> >
> >
> >--
> >Jeff Post
> >
> >Everything can be inherited except sterility.
> 
>