Power Multi Hull Shape

Discussion in 'Boat Design' started by tropostudio, Jun 16, 2021.

  1. tropostudio
    Joined: Dec 2014
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    Location: St. Paul, MN, USA

    tropostudio Junior Member

    I get it. The Hughes hull shape would take some work to locate an inboard into. Not dissimilar to the challenge of fitting the inboard electric system into the small proa in the first photos. Paired outboards on a small power cat is a much more 'natural' solution than building pods port and starboard off a tri main hull.
     
  2. tropostudio
    Joined: Dec 2014
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    Location: St. Paul, MN, USA

    tropostudio Junior Member

    Here's a power tri design by Laurie McGowan that uses a variation of the Tennant shape. He mentions the main hull is based on a tank-tested hull for an earlier 65' catamaran design. The spray rail is actually a deck at the DWL that forms both cabin sole and deck above the canoe body. Designed for 14 knots cruise, 8 knots maximum-range speed Seems like there would be a large wetted area drag penalty at the lower speeds.

    I'd be curious as to how Ghost would compare to the BW Pacific Zulu, with its stern deck raised well clear of the DWL, and to the Hughes Tri Trawler hull shape. All three boats scale to similar LD, FN and power/displacement ratios.

    Design brief: Ghost https://mcgowanmarinedesign.com/Ghost.html
    Video: https://mcgowanmarinedesign.com/Ghost_files/Ghost small 2.mp4


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  3. tropostudio
    Joined: Dec 2014
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    Location: St. Paul, MN, USA

    tropostudio Junior Member

    24m (78') Power tri Ady Gil (nee EarthRace). This is a little closer to what I'd think the underwater portion of the Hughes Tri Trawler looks like, although I'd bet his design has a narrower stern section.
    Hughes uses 2 outboards in faired pods port and starboard. Ady Gil doesn't look like a good shoal-water vessel, with the spade rudders and large, exposed props. Guess it was designed for an ocean record.


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    Also looks like a really wet ride, with a lot of expensive, sculpted structure.

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    More pics: Earthrace / Ady Gil - Power trimaran motor yacht by LOMOcean Design | NauticExpo https://www.nauticexpo.com/prod/lomocean-design/product-33511-223001.html
     

  4. Bob Oram
    Joined: Jun 2009
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    Location: oz

    Bob Oram Junior Member

    Sorry All, nothing to do with this thread, but I'm just letting people know that there is some scammer that has started a website that has the address Boboramdesign.com.au. This is a scam and absolutely nothing to do with me, it has zero legitimacy.
    Most will know I have retired.
    Please advise others.
    With regards to all.
    Bob Oram
     
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