Motoryacht project?

Discussion in 'Boat Design' started by capt_jack, Jun 14, 2010.

  1. apex1

    apex1 Guest

    A sailboat cannot recover energy by spinning a prop /gen setup! It can convert energy from speed to el. but that on a very inefficient level only. It makes no sense to slow a boat down that way and carry all the weight.
    How would a motoryacht have a benefit?
    We had that discussion here quite several dozen times, it is not feasible. period

    The CPP mentioned is the right solution to have a reliable and affordable propulsion that operates in different conditions. look here:
    That will give you a deeper insight on such system (though there are many premature comments, in the end you will see the light)

    Which boat in the range you were talking does a hull speed of 11knots? let alone 14.... right, none.

    What I say.

  2. eric le marin
    Joined: Jun 2010
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    eric le marin naval architect

    Even more generally, the best way to improve a system is usually to find the worst part of it, and focus on this part.

    Screws have a very bad efficiency, coøpared to the rest of the boat. So, it is THE thing where to put money. But that is also a very complex issue...
  3. apex1

    apex1 Guest

  4. capt_jack
    Joined: Jun 2010
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    capt_jack Junior Member

    Do you have any drawings of the process or the shape of the hull prior to the final step of sealing the ends? I think I understand how it was done now, my only concern would be the amount of stress placed on the "bend" and possible metal fatigue issues.

    I may have a couple of ideas on programs which could be used to predict the required shape needed to accomplish a desired hull but I need to make sure I understand what your starting point was prior to making the bends and welds.

    I have my own ideas about a modified composite build technique that has a similar tact in that it would be economical for a home builder but probably not offer much in the way of incentives to multiple unit construction. I still plan to follow the path of buy used / build custom later but I'd still like to experiment with some on shore scale models.
  5. EuroCanal
    Joined: Jul 2010
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    EuroCanal Junior Member


    Joli bateau. Chapeau ! Merci d’avoir partagé l’histoire et vidéo de la construction – c’était fascinant.
  6. kerosene
    Joined: Jul 2006
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    kerosene Senior Member

    because your claim that markets and manufacturers are against progress is false. There are plenty of innovations or green tech that is being sold for purely emotional reasons - not because the product is a good practical solution.

    I was reading about small windmills (<10kw) when visiting my parents farm in Finland. They are the new hot thing and being marketed by several companies very aggressively for rural homes and farms. 25K euro windmill has a payback time of 30+ years assuming no repairs is needed and this with current super low interest rates.

    I really like the idea of creating your own energy but if a system that provides few hundred euros worth of electricity per year costs 25,000 the solution is not ready.

    Hybrid is hot due to the big benefit it traffic but boats are very much unlike cars. Take a modestly powered 1.6l corolla and try to drive it at 80% power output for an hour. You cannot do that except on a race track or pulling trailer uphill. Boats do that every day. Hybrid provides nothing in a system where close to max power is used.
  7. mydauphin
    Joined: Apr 2007
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    mydauphin Senior Member

    Buying a used boat is much cheaper than building, it is the way to go but beware of fine looking boats fixed with Bondo or motors just rebuilt. There are many scammers that will sell you a boat that is falling apart and you can't tell. A good surveyor will be able to tell - well worth the money.
    Joined: Oct 2002
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    Location: Conn in summers , Ortona FL in winter , with big d

    FAST FRED Senior Member

    My suggestion is to go to "Boats and Harbors" and find a good hull.

    The hull is much of the work , almost all the risk, and can usually be purchased cheaper than you can build one todat.

    My favorite (which I own) is a US Navy 50 ft Utility boat.

    These are superb military GRP construction with fire retardant resin and full foam flotation.

    The interior is as an open boat , but a couple of hours with a sawsall and grit blade will open it up .

    They can be found with no engine and running gear (UGH) for as little as $5000 to $10,000 , complete with low time (say 200 hours) ready to drive away for about $35K.

    You can build the deck and deck house of your dreams with close to house style construction , so cheap that IF it takes 3 times to "get it right" the cost is still minor.

    50loa about 15ft beam 20,000lbs hull 45,000 loaded.

    With our antique WWII Detroit 6-71 3x1 reduction and 32 square prop we get under 3gph at 7 or so K.

    Get one with an engine and install a 30-35 ft Airstream and your cruising almost instantly.

    The yacht purists may balk but it gets a complete cruiser for almost nothing.


  9. apex1

    apex1 Guest


    Forget about Diesel electric, there is no sense on a yacht. We handled this issue already to death here............

    But you might consider a CPP being a real advantage on a passage maker.
    Read Kasten´s comments on CPP´s!

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