Re: [PSUBS-MAILIST] Hello Everyone

["Sean T. Stevenson" <cast55@telus.net>]

Bryce, welcome to the list.  You obviously have a lot of questions.  Many of 
these can probably be answered with some further research.  Aside from 
scouring the internet for answers, a few good places to start would be:

Rules for Building and Classing underwater vehicles, systems and hyperbaric 
facilities, ABS

Safety standard for pressure vessels for human occupancy, ASME

Concepts in submarine design, Burcher and Rydill

Manned submersibles, Frank Busby

and of course, everything on the PSUBS website.

To address a couple of your specific questions off the top of my head - active 
sonar is an indispensable tool for underwater navigation, and there are many 
units available for a wide variety of applications.  Radar is only really 
practical on a large sub with significant height of antenna - where this 
makes sense, you can simply pressure compensate it.  As for through hull 
linkages, you can achieve linear motion, but it is usually better to stick to 
well constrained rotary motion and convert that as necessary outside the 
hull.  Depth determination by sonar, typically referred to as an altimeter, 
is not robust.  Depth determination is usually performed with a pressure 
transducer.  While there are few if any rules that pertain specifically to 
recreational submersibles, they are watercraft and as such are subject to the 
International Regulations for the Prevention of Collisions at Sea.  The FBI 
is aware of PSubs.  Your responsibility as a designer is merely to be as 
prudent as possible - while you may not certify your sub to ABS or equivalent 
standards (an arduous and expensive process), it couldn't hurt to design to 
those specs wherever possible.  The safer we are, the better chance we have 
at staying deregulated.  Radio does not propagate well through water, except 
at extremely low frequencies.  GPS will not work when submerged.  Underwater 
navigation is achieved in most PSubs simply by a combination of sonar and 
dead reckoning.  In more advanced systems, an inertial measurement unit can 
provide position estimated based on accerations integrated over time - such 
position estimates are subject to integration error (inversely proportional 
to the cost of the IMU), and must be corrected occasionally.  There are many 
different CO2 scrubbing systems - check the list archives.

Good luck!

-Sean


On October 3, 2007 20:34:42 Bryce Yarbrough wrote:
> Hi Everyone!
>
> My name is Bryce, Jon thought it would be a good idea for me to
> introduce myself to all 500 and something of you. I am 19 and based
> in Los Angeles, and am in the design phase of my submarine. (Jon also
> thought it would be a good idea to make sure I can at least post to
> the mailing list because for some reason, my email system is
> different then everyone else's on here and he wants to see if it
> works or not. So hopefully it goes through). Other then that, here is
> the first post I planned on putting up to the mailing list several
> days ago, but because I just have to be different, I got rejected
> several times because of my email layout, so here goes...
>
>
> Hello Everyone!
>
> I am knew to this mailing list and site, but not that new to the
> world of submarines and robotics. I have been actively involved in
> robotics throughout high school and have been working with them for
> over 6 years now. I also built a small R/C Submarine, and have
> decided that a goal of mine is to build a submarine. With the help of
> my high school (we are doing it through the robotics club as a
> project, great way to get materials, electronics, and money donated
> to the submarine) we are going to build a sub. We are looking at
> about 30 Feet long with a 5 or 6 foot beam. I have run into several
> questions, that even despite my research, I cannot answer at this
> time, so I am turning to you guys :-). (btw I am 19, just to let you
> know). My questions are (at the moment that I can think of):
>
> -How do you seal up a hole in the pressure hull that contains any
> such motors to control the dive planes or rudders, if the linkages
> move forwards and backwards through the hole, instead of just turning
> (any other ideas on the subject would be great)
>
> -We have decided that we want to use a Life Support System involving
> scrubbing the CO2 out of the air, and releasing O2 into the air when
> needed.
> 	-- Anyone figured out a great system to do this with yet?
> 	--Anyone have sensors and such equipment yet?
>
> -To recharge the ballast tanks, we want to use an onboard electric
> air compressor (I just don't like the thought of fuel onboard the
> ship), anyone have any suggestions on which ones to use, things to
> look out for?
>
> -Navigation/Electronic Equipment:
> 	-- Sonar:
> 		---Any systems that anyone USES for their subs, how well they work,
> etc?
> 		---Hydrophones yet?
> 		--- Active Sonar Systems?
> 	--Radar:
> 		---Does anyone use radar for when they are on the surface?
> 		--- How do you keep the radar antenna safe when you dive?
> 	--Radio:
> 		---I am assuming that any radio designed for marine purposes will
> do, but how do you protect the antenna, any suggestions?
> 	--GPS:
> 		---I know some of the complete sonar/navigation/radar systems
> utilize GPS (which is a great thing I think)
> 		--- BUT.. again, how do you protect the antenna, and does it work
> underwater?
> 	--Depth Gauge:
> 		--The fish finder sonar systems tell you how deep the water is, but
> not how deep you are
> 		-- So how do you know how deep you are ( I would prefer to stay all
> digital, because then things can be run by the computer for
> autonomous modes and various exercises) ?
>
> Sorry its alot of questions, I know. :-)
>
> -Any laws that pertain to the use of personal subs for recreation? I
> know after the N.Y. incident the FBI is taking subs a bit more
> seriously, any tips as of yet? (We are based out of Los Angeles)
>
> I know there are some subs out there that utilize windows based PC's
> that run the navigation equipment and monitor equipment and systems
> on board the ship, so I was wondering if there was anyone who had/has
> such a system or knows what they use or how they do it, I would
> appreciate it.
>
> BTW, when I speak in terms of robotics, we do all remote control
> based robotics, so there is no actual computer interaction involved,
> its all radio based.
>
> Anything else you want to add I am MORE then welcome to take in all
> the information you guys can through at me.
> Anything involving, materials to build the hull out out(looking at
> Carbon Steel i.e. Mild Steel), viewports, hatch systems, safety
> systems, ballast systems, surfacing systems/procedures for knowing
> when its safe to surface/etc. I cannot really think of anything else
> at the moment, but I am inviting ALL forms of advice (especially from
> Peter Madsen (Kraka is my inspiration, absolutely amazing vessel!)
>
> That is all I can think of, Hopefully you guys can help me out!
>
> -Bryce Yarbrough
> byarbrough@mac.com
> +1-(818)-324-1521 if you live in the U.S. (I cant afford
> international rates, well I think it just takes away from my minutes,
> so sure, go ahead and call me from foreign countries, it will be fun!



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