24ft Bluewater cat sketch

Discussion in 'Multihulls' started by dsigned, Dec 18, 2018.

  1. Mr Efficiency
    Joined: Oct 2010
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    Mr Efficiency Senior Member

    If all I have read is to believed, the OP's "blunt" bow would not really be a resistance issue, but combined with the plumb stem, would create a wonderful fountain at speed !
     
  2. guzzis3
    Joined: Nov 2009
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    Location: Brisbane

    guzzis3 Senior Member

    Schooners predate the USA I think. Yes early boats tended to have shorter fore masts but somewhere along the way someone figured out equal length was more efficient, and then of course the ketch came along. The problem with classifying boats is it is variable. I have always loved the cosine wherry, but it is absolutely not a wherry. Every historical reference to wherrys (wherries ?) that I have found have some degree of flat bottom. Nevertheless the designer called it that and the name will stick.
     
  3. guzzis3
    Joined: Nov 2009
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    Location: Brisbane

    guzzis3 Senior Member

    The blunt bow probably isn't a problem as far as pushing water aside, cats have narrow hulls. IMO the problem is where that water goes next, into a limited tunnel where it runs into the wave from the other bow. There would be tremendous turbulence from relatively low speeds. Cats tend to hobbyhorse so high prismatic coefficient is desirable, but as I said before one design aspect can't be considered in isolation. Stuff has consequences.
     
  4. guzzis3
    Joined: Nov 2009
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    Location: Brisbane

    guzzis3 Senior Member

    I downloaded these photos years ago on the multihull forum. This was built for a tiki 26 but it illustrates teh swing wings I ahve been talking about for a folding system on a trailer for a cat to 30' ish...I wouldn't copy the engineering on this but the idea is sound.

    trailer5.jpg trailer4.jpg trailer3.jpg trailer2.jpg trailer1.jpg trailer1.jpg trailer2.jpg trailer3.jpg trailer4.jpg trailer5.jpg
     

  5. Niclas Vestman
    Joined: Aug 2017
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    Location: Malmoe, Sweden

    Niclas Vestman Junior Member

    Yup, love the simple but very fast easy handling principle. One thing I would definately change is the trailer side frames. No need for a full lengths box that will prabably hit the road as soon as the car goes up or down hill. Like when leveling out after leaving a steep driveway. Or raising the booty when the rear wheels pass a speed bump. With long overhangs like that, I would definately taper the side frames like upside down triangular roof trusses. Would also shave off some weight.
     
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