6.5 to 7.5 metre performance/cruise multihulls

Discussion in 'Multihulls' started by Gary Baigent, Feb 27, 2015.

  1. Gary Baigent
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    Gary Baigent Senior Member

    Have been reading Joe Farinaccio's very excellent "More Small Trimarans" and impressed by the Mailiette, Granger, Henseval and especially the Waters designs - plus the earlier postings here of the very neat 6.5 trimaran from Patterson - and seeing that any multihull under 20 feet is. imo, inadeqaute in length/size to fulfill the combination of decent performance and reasonably decent accommodation ... so ... new thread. Have redone some ideas for a 6.5. Two versions here of the main hull. The float/foils will be angled at 45 degrees like the Holtom foiler, beam will be single, accommodation in the main hull, for me, is luxurious!
     

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  2. Doug Lord
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    Doug Lord Flight Ready

    The 60' tri in the picture below was very similar to one I was designing about 1973 when I met the owner and builder-Gene Walker. Mine was wider but both had the enclosed wheelhouse and side cockpits. I've done some doodles of a performance cruiser 24' LOA that has a similar layout with an over square beam, 2 stage ama(like the Fire Arrow),planing main hull and lifting foils. The preliminary numbers look like it might work and even be trailerable with the side cockpits folding or removable. What do you think?
    click-
     

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  3. Gary Baigent
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    Gary Baigent Senior Member

    Thats a big, big boat, Doug (but notice it doesn't have dopey huge windows like a Gunboat). You'll have to post your doodling if you've scaled this big tri down. In a way, if reduced, it would be similar to the Patterson 21?
    And the Patterson 21 main hull is very much like a slightly smaller Jan Gougeon's Splinter. Which is understandable because he worked with the company.
    My idea with the single beam is to rotate it fore and aft (with fixed float/foils connected) to trailer the small boat. Similar to early ideas with Sid. Working on some new drawings.
     

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  4. Doug Lord
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    Doug Lord Flight Ready

    Yeah, it would be similar to the Patterson-but Genes boat made smaller is what I saw when I first looked at the Patterson. She'd be sailed from the side cockpits.
     
  5. Corley
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    Corley epoxy coated

    I agree Gary to me 20' is just that bit too small. Some really nice accommodation options open up once you add 5' if you did a double shuffle type main hull like Kurt's designs you would get a tiny bit more sole space which would be handy in a small boat.
     
  6. Doug Lord
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    Doug Lord Flight Ready

    I'm exploring the Serena concept at 24' X 24' more or less..
     
  7. Gary Baigent
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    Gary Baigent Senior Member

    Here's an early sketch of "Bad Insect" - with the plan form open for sailing and closed for trailering.
     

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  8. redreuben
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    redreuben redreuben

    Gary, I reckon the Patterson looks like a small Verbatim !
     
  9. Gary Baigent
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    Gary Baigent Senior Member

    Definitely the Crowther-like bow, yes, but the rest of the Patterson design is very Jan Gougeon ... whose work I've always admired. Not so sure about some of the aesthetics of Strings though.
     
  10. Doug Lord
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    Doug Lord Flight Ready

    Fire C 24

    This is a rough doodle of a boat that has a lot of inside space and two side cockpits with windscreens. It uses the 2 stage ama as on the Fire Arrow test model. Would be designed to be built very light and have great performance potential if not loaded too much. She would be designed for primarily intercoastal fast sailing and up to a 2 week "cruise" and might be suitable for limited close in ocean sailing.
    Both the main hull and amas would be planing and both would use lifting foils.
    Foils would be configured for the type of area that the boat would primarily be sailed in-that means they could be configured to work in relatively shallow water(2-3') if necessary. She would probably be trailerable when disassembled or folded.

    click--
     

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  11. Gary Baigent
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    Gary Baigent Senior Member

    Couple more sketches of the Bad Insect (we have a dangerous fruit fly problem here in Auckland at the moment, could destroy our orchards).
    This is a somewhat fatter (fruit fly) version of what I normally do. Meaning more room, have to force myself to cut down on the minimalist stuff. Still a small boat though and the juggling act is tricky.
    LOA 6.5 m
    BOA 7 m
    wing mast height 9.5m
    SA total 20m2
    reacher 7m2
    weight 140 kgs?
    Your design is interesting, Doug - too many foils though. Just joking.
     

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  12. Doug Lord
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    Doug Lord Flight Ready

    Thanks, Gary!
     
  13. Gary Baigent
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    Gary Baigent Senior Member

    It's interesting the rocking motion your overpowered model exhibits. On Sid, before i reduced the foil depth, did this too - which felt wrong but the boat still travelled at same speed. Once the foils were shortened (lifting J foil area stayed the same) this disappeared - because the windward foil was now clear of the water surface. Figure that out. The only time Sid rocks to windward now is if there is an abrupt wind change and we're caught aback, like behind a headland.
    Bad Insect is just a simple foil stabilized design ... although I'd expect it to fly in breezy conditions.
     
  14. Doug Lord
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    Doug Lord Flight Ready

    The last video( when the boat was not overpowered) it rocked twice on a broad reach in quartering waves-it's not not endemic to the design-watch the foiling just before that-straight ,level, "no rocking motion"(no quartering waves).
    The only reason the boat rolled at all in the last 15 seconds was because of the powerboat wake that combined with the other left over waves. If you were in constant conditions like that simply lowering the leeward foil a bit would eliminate any roll but I'm not going to go thru the hassle of doing that on the model but it was always planned to be a possibility on the full size boat. If I had headed up or down that would have nixed the roll as well. The roll was not a problem and as soon as the wake went by she was perfect.
    -------
    Take a look at this video at 24 sec in to 33 sec in on port tack-straight level, no pitch, no roll then watch the rest of it carefully and you can see the powerboat wake come thru. That would have caused any three foil foiler to roll in a similar way-but no pitching in either sequence. Keep in mind the wind was only 5mph....
    Tacking was poor because of the radio set up, but if you watch the long version she tacked most of the time.

    https://www.youtube.com/watch?v=7Mok3d4KiMI
     

  15. Sparta
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    Sparta New Member

    Hi. I'm new here.
    I have visited often but don't have much spare time for posting, but thought I would post in this topic. I recently built a KD650 catamaran. 6.5 metres long, can sleep 4. A bit more cruiser than racer but still goes ok. I made a blog about the build and boat here http://kd650.blogspot.co.nz/
     

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