50ft Fast Cruiser

Discussion in 'Boat Design' started by Fil49er, Oct 24, 2013.

  1. Fil49er
    Joined: Jan 2013
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    Fil49er Environmental Architect

  2. eyschulman
    Joined: Jul 2011
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    eyschulman Senior Member

    Looks like all the other modern sailboats lots of competition out there.
     
  3. Fil49er
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    Fil49er Environmental Architect

    Yes you are right. I tried to put unseen elements on it. Usually these elements are placed on bigger boats.
     
  4. dskira

    dskira Previous Member

    How do you know she will be fast?
    Did you tank tested models or did some self propelled model?
    The word "fast" always puzzle me for a sail boat.
    What means fast for sail boat before she is built and tried?
    50' in length give you natural performances due to the size than a smaller craft, but even the most beautiful design can be a real dog.
     
  5. Fil49er
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    Fil49er Environmental Architect

    Yes, U r right. For a definitive result u have to do tests or build the boat. In any case when u design a hull u have to consider different coefficients, eg. CP, WA, Hull form etc.
    Every parameter, if considered, can give u infos about ur design.
    I choose to design it not only for regattas but also for a confortable interior.

    Doing examples.. It isn't a Swan but it's more similar to an Ice yachts.
     
  6. daiquiri
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    daiquiri Engineering and Design

    Again, very nice work there.

    I don't like the idea of piezoelectric sails, which is an unnecessary complication with almost no practical benefits. The current best nanotechnology-based piezoelectric generators can give 20-30 mV at 3-4% efficiency. And they work by applying a continuous motion to the structure which hosts them (in this case, a sail). But the sails don't work that way. Once in tension under the wind pressure, the gross part of the sail area will not move and will not generate the current. In order to let the generators work, the sails would have to continuously flutter. It happens on well-trimmed sails only when close-hauling under significant winds, and only near the leech (the trailing edge of the sail). The available mechanical energy due to flutter is very small, because sails are very lightweight (flutter under modest aerodynamic forces) and the fluttering area is very small. The piezoelectric conversion efficiency is ridiculously small, hence the combination of the two gives an almost neglectable generated power. It is definitely not worth the costs, the technical complications and maintenance problems.
    I'm pretty sure you are very aware of it, but please let me say it - let's never forget that we are dealing here with things (sails) which will occasionally be exposed to very harsh ambient conditions. When designing a sailboat, it is sometimes better to have in mind tractors than airplanes. For this reason, avoiding any unnecessary technical complication is always a wiser choice.
    Cheers!
     
  7. TANSL
    Joined: Sep 2011
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    TANSL Senior Member

    The boat is beautiful and I can not do anything but praise its design.
    From the technical point of view, from an angle of heel of about 18 degrees (this is an approximation as I have no the body plan) the vessel undergoes a sharp and rapid decline of KN values​​. Have you taken into account this feature and have any significance?
    Congratulations for the rendering.
     
  8. michael pierzga
    Joined: Dec 2008
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    michael pierzga Senior Member

    Also consider that fast and lightweight boats dont work as cruising platforms. After a few months you hate your boat

    I spend my life chugging around at half power because speed is simply to stressful.

    By stressful I mean that cruisers are operating very close to the shore, inside the reefs, nearly on the beach, with suspect charts .
    Go fast and you must be glued to the nav station, thinking way ahead, while hoping for the best. Not fun, not fun at all.

    A perfect cruiser has a very powerful sailplan to take advantage light wind, superior upwind performance, enough displacement and storage to accomodated a massive pile of supplies and liquid, a keel that is designed to withstand punishment, contruction that stays tight and stiff for decades, an underwater profile that can be blocked up without a cradle...........

    lightweight go fast designs miss every detail
     

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  9. Fil49er
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    Fil49er Environmental Architect

    I agree with u.. really agree!! It was a sort of future provocation..
    I would insert a piezo plate on my skis http://www.filippocima.com/1#!cftiwood-skis/c21ta and i get infos about it. It's a good technology if u have strong and intense vibrations. I choose it to haven't batteries onboard, or to have few of those, feeding immediately components onboard. Unfortunately too young technology..
     
  10. Fil49er
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    Fil49er Environmental Architect

    It's an interesting observation.. I would understand more about. Can you explain it better?
     
  11. Fil49er
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    Fil49er Environmental Architect

    It is a tipical Mediterranean see design. The stern is low and the hull isn't so "fat" to support Ocean crossing. It could do that because it is very strong but It's a different experience compared to a cruiser sailboat. It's more similar to an imoca 60, with a hull designed for downwind
     
  12. TANSL
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    TANSL Senior Member

    I'm afraid you have not taken into account any aspects of naval architecture of your ship. If so, and I would like to be wrong, it makes no sense to try to explain what is the KN because it would be difficult for you to understand me. If you already know what is the KN, please be more specific about what are you not understanding and I'll try to explain.
    Not meant to bother you, but to help.
    Cheers.
     
  13. Fil49er
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    Fil49er Environmental Architect

    yes I took every aspect in consideration.. my question is about 18°. How can u say that looking a picture.
     
  14. michael pierzga
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    michael pierzga Senior Member

    Sure...its lightweight, lightweight boats surf. After you have enjoyed surfing and have to come back home...... oh my !

    And that low transom removes very much valuable storage space. when you eliminate this storage your crew end up sleeping with the boats fenders and using pillow cases full of garden hoses as cushions..

    Its a shame that authentic racer cruisers went out of fashion. At one time Swan built the finest...now they follow fashion and produce boats that no one loves.

    Those old fashion Swans are still around, still cruising, still winning races.
     

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  15. tom28571
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    tom28571 Senior Member

    True, true.

    I cannot understand the fad for open transoms on other than racing boats and would not personally have one on a keelboat, ever. IN this case the open transom is the same height as the bridge deck. What's up with that?
     
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