Affordable, long-term liveaboard?

Discussion in 'Projects & Proposals' started by Filmdaddy, Aug 4, 2005.

  1. Sailor Alan
    Joined: Mar 2014
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    Location: Gig Harbor WA

    Sailor Alan Senior Member

    You are asking the wrong person on this. I not only didn't listen during chemistry, i rarely attended, so any material above atomic level i am woefully ignorant of.

    There are several ways to separate water from seawater that i know of.

    The first, and most common, is boiling, and subsequent condensation. The biggest issues with this is getting rid of the salt concentration. I assume efficiency can be increased by reducing pressure above the water surface?

    The second is freezing, though we see it rarely. Technically, fresh water freezes at a much lower temperature than salt water, so fresh water could be skimmed of that way too.

    The third is electrolysis, where passing electric current through salt water, you get hydrogen and oxygen as gasses. Submarines use this method.

    The forth is osmosis, where pure water will pass through minute capillaries that impurities cannot pass through. From personal experience Kevlar, Noamex, and other nylon derivatives will osmote water just fine, and i suspect if there is a partial vacuum on the non water side, they work even better. Why do they call it 'reverse osmosis" when it is actually osmosis? Can you put cut celery in salt water and expect it to osmote up only fresh water?
     
  2. Yobarnacle
    Joined: Nov 2011
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    Yobarnacle Senior Member

    Only thing I know about celery, other than it tastes good and is good for you, is smells good. The perfume is much nicer than the odor of boiling shrimp or crabs in my house. So we always throw a stalk of celery in the boiling pot, for the "white noise" perfume it emits.
     
  3. NoahWannabe
    Joined: May 2014
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    NoahWannabe Junior Member

    Modified Dory Hull, Proteus WAM-V, Ram Wing and Solar Turbine

    Lotek: Other than dory looking hull, it doesn't have any features I am looking for. It doesn't have true dory flat section on the bottom of the hull. I need flat bottom on rear half of the main hull(s). It need sea bright hull type of keel for engine mount and propeller protection. Bartender like full transom to prevent porpoising. AND most importantly, adding retractable lifting strakes or lifting foils during high speed cruise.

    Proteus: I have heard of this boat when they first announced it years ago. It doesn't have dory hull to increase displacement with minimal draft change. 30 knots top speed is just being logical for modern scheduling requirement. Being sea-sick friendly is smart for allowing majority of population to be on ocean when they need to without building up sealegs. WAM-V, Wave Adaptive Modular Vessel is not new. The Aleut Iqyax had this flexible frame for skin-on-frame kayak (SOF) designs for millenia. SOF frame pieces move with shape of the wave for safer and efficient maneuvering.

    The coastal passage (cheap cat construction): I agree completely. Most popular designers such as Richard Wood and Bernd Kohler all use similar build techniques. Good marine plywood hull with strong fillets covered with glass fabric and epoxy is time tested construction method. I would vary with hybrid foam/strip core for complex curve sections. Foam for rigidity and/or insulation is still being considered.

    Ram Wing: I need more research on this. I don't need much lift, just enough to reduce drag to get my top speed. There must be some compromise point where I can reach my top speed, but headwind doesn't cause the boat to flip or lose control. Or it can be done with Ram Wing and lift foil, so either one by itself doesn't get into trouble, but combined it produces enough drag reduction for my top speed requirement.

    Solar turbine generator: So it is a thermal collector with condenser on backend. Basically a turbo jet engine in solar energy version. Thermal expansion and phase contraction to produce push-pull pressure to drive a alternator. I like it! :) Find a optimal phase medium and it should work fine. I like this version much better than 3 phase alternator and conversions. This sounds much more practical than my solar thermal stierling engine concept. There is some familiar technology here. It isn't same but there was some invention few years ago using some similar concepts. you should pursue this one. This isn't as fun as a sail wing flying boat, but much more practical and money potential.
     
  4. NoahWannabe
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    NoahWannabe Junior Member

    Celery in the crab pot sounds good. i will give that a try :)
     
  5. Sailor Alan
    Joined: Mar 2014
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    Sailor Alan Senior Member

    I apologize. The inclusion of the Lotek, and the Proteus were jokes, like the burning fuel under the bride deck for thrust.

    I’m glad you like the Coastal passage construction process, one of my favorites.

    I’m getting the idea now i hope. Ram Wing for speed, catamaran for stability. We need to go back to the dawn of catamarans, CSK for instance, for inspiration for this kind of hull.

    With a length of about 38-40’, we need a beam of 16-18’. Smaller works too, 36’ X 14’ perhaps. The hulls will be dead flat bottom, no rocker, with 5 degrees flair on the outside, and 30 degrees flair on the inside. The maximum WLB of each hull will be 2’ at full load heavy. The minimal flair on the outside increases the basic stability for sailing and no seasickness. The great flair on the inside will give a small difference between full load, and light load WL, and assist in focusing air under the bridge deck. The hulls will be double ended, with NO dagger boards, center boards or foils of any kind. The bridge deck bottom front will be 5’ above the LWL at rest, about 4-5’ from the bow proper. The lower bridge deck (bottom) will curve down, then run straight at a slight angle to the stern, finishing about 24”-30” above the LWL at rest, about 4-5’ from the hull stern. Longitudinal stringers will be external, i.e. underneath, outside on the bridge deck. This bridge deck will lift the boat during high speed running, relieving nearly 40% of the boats weight.

    Accommodation will be spread around the hulls, and include standing headroom at the rear of the bridge deck anyway. Actual layout TBD. Suggestions please! As a starting point, i suggest a double bed in the stern of each hull, and a bathroom in each bow, both hulls the same, mirror images. The bridge deck holds the galley right aft (standing headroom) with a dinette and table forward. Like all catamarans, reducing weight will be very hard work. To get them strong enough and still light enough is very difficult, though Plywood over stringers and bulkheads works very well indeed.

    Sailing, the hulls will be fairly deep draft, so no need for CB’s etc. As it powers up, the draft will reduce, but never actually leave the water, so no pounding. The hulls will never ‘plane’ as all lift will be provided by the “Ram Wing”. Note; this is important as air leaking out the ‘side’ would destroy the ‘ram’ effect.

    Electric motors and propellers will be provided at the stern of each catamaran hull, with some batteries for auxiliary drive, and maneuvering. These can be additive for high speed, perhaps 25+hp each, and the OB merely 250hp.

    A mast and rig will be provided for sailing, though its height will severely limit overall speed under power. I suggest a deck stepped mast, or “Norfolk Broads” (see Bolgers AS series) type mast lowering system so the mast lays flat for speed. I also suggest a Gunter Lug ketch/schooner rig so the spars and masts are all short and easily stowed for high speed.

    Now a separate boat will be built, preferably narrow dory (Pacific Power Dory) style, flat or ‘warped’ bottom, 5’ WLB, 7’ beam at the gunwale, 22’ long, with a gunwale tapered to match the underside of the bridge deck. See Payson’s Diablo Grande http://www.instantboats.com/diablog.htm
    This open, or partially decked, center console, auxiliary boat will have a 250-300hp OB on the transom. Latched securely under the bridge deck, it will power the whole rig; separated, it will provide mind blowing performance as a fishing or auxiliary cruiser.

    Note; i would prefer a shallower or flatter bridge deck, and a ‘flap’ system to adjust ride height, and so the aux boat can have higher sides, but the above measurements will work.

    Incidentally, a boat like this would be quite comfortable to live on, and very comfortable at sea. I would take it offshore, but not everyone would. Offshore, i would stow the OB, and stow the aux boat somewhere, possibly having folding sides and stern on a flat, sealed bottom, (like Dynamite Paysons sail board) to do so.
     
  6. Yobarnacle
    Joined: Nov 2011
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    Yobarnacle Senior Member

    While standing headroom in bridgedeck houses is difficult to achieve in less than the largest catamarans, the bridge deck seems ideal for installing bunks, double or single, accessed from the hulls, where standing headroom is possible. An extra wide double berth could reach completely across the bridge deck and be accessible from both hulls.
    A master cabin of great breadth, equal to the beam.
     
  7. NoahWannabe
    Joined: May 2014
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    NoahWannabe Junior Member

    I do like Proteus even if you meant it as a joke. It has many features I am looking for. It just wasn't as original as it claims to be imo.

    One of the key requirement is trailerability/transportsbility. I still like trimaran concept with 8' wide hull and standing headroom in the main helm without wave slaps. Trimaran with retracting amas and sail between the akas should provide reef-able aerodynamic lift.
     
  8. Sailor Alan
    Joined: Mar 2014
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    Location: Gig Harbor WA

    Sailor Alan Senior Member

    The original catamarans by CSK had very deep hulls and very high bridge decks, to reduce wave slap as much as possible. Standing in their hulls, you could hardly reach into the bridge deck, so these designs (Sea-smoke for example) tended to have separate hull and bridge-deck accommodations. The early British, and most early French catamarans tended to have lower hull depth, and much lower bridge decks, far too low in my opinion. These boats did tend to have standing headroom in the hulls, and bunks, or double beds really in the bridge-deck.

    In this case, the hulls have to be quite deep so the ‘air cushion’ remains trapped under the bridge deck, whilst the front of the bridge deck needs to be quite high above the waterline, and the stern of the bridge-deck must be fairly low. This stern of the bridge deck can be made just as high as the front, and a ‘flap’ substituted for rather quieter sea operations, but this suffers from diminished bridge deck headroom.
     
  9. Sailor Alan
    Joined: Mar 2014
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    Location: Gig Harbor WA

    Sailor Alan Senior Member

    What a good idea, i had not even considered it before now. In fact to make it work, the ama hulls would need to be very deep and extremely narrow, to reliably trap the air cushion whilst the whole hull set lifted up as the displacement (weight) was offset by the aka’s lift. Ill think about it.

    Along the same theme, a catamaran with 90” total hull height, and a max 18” wide flat bottom, max 22” wide at the WLB, 36-39’ long, and a maximum width per hull of 72-76”, could be made into a pair of demountable hulls, with the bridge deck mostly sailcloth as you describe. Unfortunately the bottom of the bridge deck is subject to quite large forces per square foot (not at all like a wing) so will need a lot of support, for and aft battens in pockets in the sailcloth for instance. With the above dimensions, such a vessel could be demounted, and one hull turned upside down, and the whole stowed in a container, or on a low loader truck. Hardly ‘transportable’ in the classic trailer to home style, but workable none the less.

    This would probably need two prime movers, OB's or the like, as there is not really room in the container for the center boat.

    Consider this as inspiration.

    http://www.ikarus342000.com/DUO900page.htm

    This is too small, but can be used as inspiration and scaled up. The inner hull side would be angled inwards quite a lot more then this, perhaps 40 degrees. The bridge deck would be somewhat similar, but rather longer and further forward so the lift is distributed correctly, and the coachroof contributes to lift, rather than destroying it (as here). The rig would be more suitable for cruising as well, probably two masts. The bridge deck would need a double skin of textile, upper and lower, both supported fairly closely with flow-wise battens, but as you say, could be reefed as well.

    I’ll include a cartoon in a few days.
     
  10. CAPT D
    Joined: Feb 2015
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    CAPT D Junior Member

    Hello Guys, Is There Anymore Information About The "affordable- Long -term-liveaboard Vessel Shown Above,

    It Looks Similar To What I Am Putting Together, It Would Be Nice To Talk To The Designer/owner

    Thanks For Any Help You Could Offer
     
  11. Kai Rabenstein
    Joined: Jan 2019
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    Location: Hastings, UK

    Kai Rabenstein Junior Member

    Currently in the very early stages of a commission for a 12m/40ft aluminium trawler catamaran - probably going to be a variation of Francois Lucas' Jxx38 design (I am negotiating with him about changes or a new design). Intended as both a liveaboard and green technology demonstrator. Comments/discussion would be welcome.
     
  12. Dejay
    Joined: Mar 2018
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    Location: Europe

    Dejay Senior Newbie

    Hi Kai,

    from what I've learned aluminium is (way) too heavy for a boat that is driven by green energy. The most lightweight boat per length I've seen so far is the 15m harry proa (10m windward hull) with 2t lightship presumably because of FEA engineering and very light fiberglass on 20mm foam core. It also features some very intriguing ways (at least to me as a novice) to build using simple melamine molds and vacuum infusion (learning curve but overall seems manageable and cheaper / lighter / faster).

    I'm also interested in building a solar powered liveaboard cruiser for coastal cruising along the shores and in the rivers of Europe. Thanks for reviving this thread I guess I have to read all 15 pages now!! :) There are a lot of people interested in this but not much proven builds.

    From my very preliminary findings something with a 42m² solar panel surface (big already) and a 4t and 12m LWL displacement catamaran, you would have a solar harvest of 41kWh per day in summer (in the north sea / London / Hamburg) and could run 87 nautical miles a day at 6 knots with 2.84 kW motor input power (assuming 50% propulsive power efficiency). Interestingly you can also get about the same range in the summer in Reykjavik but in the winter you'll need to migrate to the mediterranian or go very slow or use a generator. 8 knots would also be possible in the summer in the mediterranian (66 NM range at 7.3kW power).

    But from what I've learned weight is the most important thing followed by enough length to have low enough drag at 6 knots. But it depends on your use profile and your budget for batteries.
     
  13. Kai Rabenstein
    Joined: Jan 2019
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    Location: Hastings, UK

    Kai Rabenstein Junior Member

    Thanks for your input Dejay - if you are at a similar stage than it might be good to keep exchanging ideas! There are certainly plenty of handy tips in the preceding 14 pages of this thread ...
    My projected boat would rate about 7.5 tons lightship, and so I reckon I would need 2 x 50kW main engines which in turn will require substantial battery capacity.

    I provisionally chose aluminium in part because the boat will have a blue water “A” rating, in part for the ease of repair or adaptability, and in part so that even as a wreck it would still retain material value.

    Otherwise it is meant to be akin to a smaller version of the Swiss SolarWave boat (which logged a round-the-world equivalent mileage as a 10 ton fossil-fuel free craft with 38 sq.m. of solar panels), to show that almost anybody who is prepared to forgo speed can indeed go green ...
    Kai
     
  14. Dejay
    Joined: Mar 2018
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    Dejay Senior Newbie

    Yeah, my ideal would be to find others to cooperate. Either just on the design and engineering, or even with building. If you would build 2 boats of the same type with 2 people it would be much easier than building alone. More people even better, you could share costs for design and engineering and space to build and buying things in bulk. Problem would be finding people who want the same kind of design!

    Have you looked at the flatcat solar? It's closest to what I want, but no plans available to buy. I'm also looking into trimaran (less structure less weight?) or proas (even less structure) and considering crazy ideas like a hydrofoiler or swath hybrid.


    I would love an aluminium boat as well especially unpainted with that natural olxidized gray silver look. I've looked into it for the same reasons you did, it's a great material but I think just not right for solar power. I'm not trying to disparage, just my thoughts on this.

    Especially if you're looking for long range cruising. My use case is staying in one spot for a few days near a city or harbor an anchor and recharge, then go on a trip. In that use case a large expensive battery can compensate for increased power use, but for long range cruising it doesn't (because you mention blue water rating).

    Of course twice the weight will only translate into something like 1 knot less or so. Maybe that is fine. But it's not "ideal". There are also disadvantages, I believe the "intelligent infusion" will be cheaper and less work to do. Aluminium is not that easy to learn to weld. With aluminium you end up with lots of stringers and bulkheads and the interior finishing and insulation will be more work than a foam core hull.

    There is also a story about someone who build his own aluminium boat, supposedly unsinkable with watertight compartments. Then one night there was a "clonk" and the boat sank pretty quickly (nobody got hurt luckily). A foam core boat you can saw in half and it will still float.

    You'll have more maintenance with painting the hull but repairability is probably at least equal. Just carry 10 liters of resin, some fiberglass and some sandpaper to repair anywhere in the world.

    The last point is that I want to build the boat in parts in my back yard and then transport it, so I believe lighter weight makes it much cheaper to transport and assembly might be easier in parts with fiberglass.
     

  15. Kai Rabenstein
    Joined: Jan 2019
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    Location: Hastings, UK

    Kai Rabenstein Junior Member

    Your parameters and preferences are clearly a little different from mine Dejay - but as you indicated, a polished but unpainted aluminium hull does not require much annual upkeep and can look quite smart ...

    Regarding long distance passage making I intend to rely to a large extent on kite sails (and besides the solar panels on wind turbines as well as a regenerative propulsion system to keep the batteries topped up)!

    My boat is going to have to be built in a commercial yard with perhaps some DIY contribution to the internal outfitting - expensive but necessary. Regarding foam core hulls that is a brilliantly safe and cheap idea but sacrifices the hull space for accommodation purposes, hence would not suit me ...
     
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