Ok someone asked me (Jim) where I?m going with this so here is the concept broken down by area so far. Group input is solicited and greatly appreciated.
As I read more and look into the subject, I can see that modern epoxy-ply boat building techniques and a dry ambient pressure design are a match made in heaven for my intended application. As to the question of size, I am working out several options each with it?s own set of compromises. In any case, the project will be a significant investment in time and money.
If I want to keep in scale with the Disney - Goff boat and have some degree of comfort, it looks like with frames / stations spaced at around two feet, this would be something in the order of 36? L.O.A. (rough estimate). That is trying to keep her less than 10,000 lbs surface displacement if possible; again I have yet to do the calculations. The idea is a submarine cabin cruiser with some pretty serious panache, and if I can?t make it work, accidentally sink her, or get too old for diving (45 now I?ve got time I hope), the whole shebang can be converted to strictly surface use still with the underwater view ports. Really nice options here.
If I can?t keep her to scale and have to take a little ?creative license?, the one requirement is to have 6? standing headroom in the pilothouse for two; sitting for too long can be dangerous (peripheral circulation) and uncomfortable. In the main saloon area one may have to duck through in order to keep scale and the size reasonable. A convertible dinette to starboard and a galley to port, each centered under the round Plexiglas view ports and Victorian era décor right down to fake rivets on the interior. A porta-potty finds a home somewhere.
One problem that I see for me with this hull design is draft at D.W.L. is looking to be about 5 feet. If I run propulsion at an angle out of the bottom I could ballast her higher and lower in the water at will but I lose the efficiency of the straight shaft as well as the spirit of the design.
Another option is to go tiny, shrinking the cost and complexity as well but forget about any family members feeling comfortable about it and that?s no fun. This vessel as conceived, would be suitable for long distance surface travel throughout the Florida Keys and maybe even an occasional ?patrol? to Bimini to sink a fishing smack or two. :)
At that weight she would require a little diesel in the order of 25 hp to move her at hull speed (maybe a little more with all that drag), I have no idea what the electric motor requirement would be at this point (group input here) and I envision some type of coupling system to the main shaft so both motors can take their turn. I don?t need too much underwater endurance (motor wise), just some degree of control as I envision putting the boat on the bottom (sandy patches), most dives.
The little motor might not turn a big enough alternator to charge the battery requirements (group input) so a small gen-set may or may not be required. Then there is the question of charging the air cylinders and you see a real engine room emerging. And in Florida, in a black / gray submarine with a grand total of two hatches topside, a 5000 btu marine air is a requirement on the surface. The design has to work the first time out, flood her and everything has to be torn down for rebuilding. Did I mention time and money?
Batteries (non-gassing)an lots of em, need to be as low in the hull as possible and may possibly be split into two banks fore and aft if not in the bilge centerline, depending on ballast tank arrangements.
I intend to follow the technology of the WWII fleet boats and await the NAVPERS manuals I ordered from www.history-on-cdrom.com which are quite detailed. The Nautilus hull appears to lend itself nicely to the same conceptual arrangement however, the problem of size (beam) arises here. I do not yet know the size requirements of the ballast system; its relationship to interior volume, and more research is needed in this area.
The same goes for the high-pressure air requirements and placement of those bottles may pose a problem for Nautilus depending on size and quantity. All controls run to a manifold in the pilothouse controlling both ballast and life support with one isolated secondary safety system having sufficient capacity to surface the boat. I do not yet know if a drop weight system is to be incorporated or not. The system may be sufficiently complex enough to require two crewmembers to control the boat when diving.
I noticed that the fleet type boats placed their bottles low in the hull and this may pose a problem for me configuration wise. There would be some space under the top deck (not much) but this would be too high for stability reasons. Perhaps in the ballast tanks themselves, this still needs to be worked out.
Some type of pressure relief valve(s) is required to vent cabin air overboard and keep Davy Jones at bay. I do not yet know where these are available, how many, flow capacity requirements (group input) or how they function (mechanical or pneumatic). Some manner of precise cabin airflow regulation is also required.
Here again more research is needed. I want to get away with as minimal possible hull material and still maintain a reasonable margin of safety and sea keeping ability. I see her going together on a strong back, plating over frames and bulkheads, standard stitch and tape epoxy construction, chine logs, butt blocks, etc. Lloyds certified marine ply throughout saturated with epoxy and exterior surfaces either glassed with GRP or another material I believe is called Dynel. Interior surfaces saturated with epoxy and painted to suit.
Someone mentioned to me "oil canning" of the hull and started me thinking about a lag in pressure compensation going both ways. The Gorgean brothers have done extensive research and stress analysis of marine plywood and cycling stresses so that work in conjunction with what I learn about ambient pressure hull design, will determine the specifics of materials and framing. I envision something like four bulkheads at this length among the frames with longitudinal requirements yet to be determined.
The exterior will be in keeping with the spirit of the design, right down to the 19,000 or so fake rivets on the hull. Did I mention time and money? In fact, I don?t need to bother hiding the glass tape on the panel joints either, take a good look at this surface. http://www.vulcaniasubmarine.com/The%20Eleven.htm A whole lot of wetted surface but I don?t care about going fast and the diesel will be efficient enough despite this.
In all my years of diving, I have never felt the desire to do saturation diving nor is that likely to change. I have plenty to see at less than 50 feet. The boat would never submerge unless those aboard are scuba certified, pony bottles would be secured to the bulkheads clearly marked and lit. She would never initiate a dive in greater than 25? and never venture where the bottom is greater than 50?.
And finally in the event there is a failure of the ballast tanks to blow or some other failure, a provision to flood the boat and exit one of two hatches would be made. Static stability would be designed to ensure that those hatches remain upright. The hatches themselves would be robust enough (Freeman) to ensure that any potential warping of the hull leaves them operational. As a last resort, the transporter could just ?beam? you ashore! (Just kidding?maybe:)
So there it is, my very own mad scientist project! I even have my own version of Vulcania as a building location.
Regards
Joe
From: Jim Pesanka <jpesanka@yahoo.com>
Reply-To: personal_submersibles@psubs.org
To: personal_submersibles@psubs.org
Subject: Re: [PSUBS-MAILIST] Nemo's Nautilus
Date: Fri, 28 Oct 2005 00:39:10 -0700 (PDT)
Hi Joe,I replied to you earlier, but it posted under the heading "another nutcase" so you might have missed it. Would you tell us how big of a Nautilus you are contemplating? Knowing that seems necessary to answering the questions you asked.Cheers!Jim
Joseph Perkel <joeperkel@hotmail.com> wrote:************************************************************************ ************************************************************************ ************************************************************************ The personal submersibles mailing list complies with the US Federal CAN-SPAM Act of 2003. Your email address appears in our database because either you, or someone you know, requested you receive messages from our organization. If you want to be removed from this mailing list simply click on the link below or send a blank email message to: removeme-personal_submersibles@psubs.org Removal of your email address from this mailing list occurs by an automated process and should be complete within five minutes of our server receiving your request. PSUBS.ORG PO Box 311 Weare, NH 03281 603-529-1100 ************************************************************************ ************************************************************************ ************************************************************************
I would like to thank the group for the responses I have received which have been both encouraging and informative. I will be responding to individuals shortly however, as predicted, hurricane Wilma has knocked out our power and wreaked a bit of havoc here yet again, so I am writing this from work where priority services have been restored (a hospital).
Thank you
Joe
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