6.5 to 7.5 metre performance/cruise multihulls

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

  1. pogo
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    pogo ingenious dilletante

    Having the drifting angle in mind, i think the boat benefits more from the "planing lift" than from dynamic lift of a totally submerged foil, thus the enormous spray in the second pic.
    Similiar in the first pic, drifting angle causes wake at foil's bow.

    Sorry for my bad english.

    pogo
     
  2. Gary Baigent
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    Gary Baigent Senior Member

    I agree, Pogo, more a planing float design than a foiler, hence all the spray. A daggerboard in the main hull would have radically changed this boat's beating performance - and probably would have reduced all the lee float fuss too.
    Interestingly Noel Fuller sailed this little, square boat, around 11 feet, (no. it was over square if I remember correctly) from Auckland to the Bay of Islands, 120 odd miles.
    In lighter winds the windward float/foil hooked the water - and according to Noel, held the boat flat and allowed good performance to windward. He might have thought so - but I didn't when I sailed Sabrina. There are many who believe in this windward hooking performance ability. They are delusional - I say in my impolite and undiplomatic manner.
    Your English is fine.
     
  3. waynemarlow
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    waynemarlow Senior Member

    Wasn't there a foil recently UK patented that was a water planing foil, it was fitted to a number of boats and was said to be the next big foil thingy ?
     
  4. Gary Baigent
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    Gary Baigent Senior Member

    Have been watching way too much World Cup cricket (and the bloody Aussies won - actually they deserved to, however cruel and difficult that is to swallow) - but have been, in between matches, building the "epicentre" of the 6.5 metre.
    The double ring frame, height and hull beam is larger than 8 metre Sid's - so when finished, there will be absolute freedom and gracious living below deck on the 650?:p
    Been re-thinking the rotating main beam; Jacques suggested, instead of bolts to lock it in place, to use block and tackle to cleats, spread the loads at the attachment high pressure points with carbon. The system could be inside or outside the beam and hull - but internally would be neater.
     

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  5. patzefran
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    patzefran patzefran

    So the ring frame will be a piece of the male mold for strip planking the main hull ?
    Red cedar and Polauwnia are same the price as gold here in Europe !
     
  6. Gary Baigent
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    Gary Baigent Senior Member

    Yes, becomes a permanent part of the male (and female mould/frames) if I go to paulownia strip planking. Paulownia is not that cheap here either - although I know a certain bloke down country.
    But it is possible to build the same convex/concave cross section shape in 3mm ply - so at the moment I'm leaning that way.
    Just ripped down and into some 4 metre lengths of 10x10mm thick oregon for stringers and gunwhales and a 20mm square thickness for the keelson.
    My old friend Don Gifford jeers at me for building multihulls in sticks and string.
     
  7. patzefran
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    patzefran patzefran

    The stringer and gunwhale size is much smaller than hard chine stringer and frame, interesting ! Keep us informed about 3 mm ply planking.
     
  8. Gary Baigent
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    Gary Baigent Senior Member

    Roughed out (very crudely) what the 6.5 main hull might look like, checked proportions and angles; will look okay. Need to make forward bulkhead and a couple of ring frames for bunk supports, then can begin assembly.
    But as already mentioned, backyard is illegal and out of bounds.
     

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  9. warwick
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    warwick Senior Member

    I thought it would make a good starting point Gary
     
  10. oldsailor7
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    oldsailor7 Senior Member

    Buccaneer 24 = 7.4M. Qualifies for new 8.5M class.
     
  11. Gary Baigent
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    Gary Baigent Senior Member

    Getting serious. Lifted back shed to be level with main shed and cut two big holes through the metal walls with screaming grinder. Lucky the critical partner was visiting friends in Coromandel.
    A fait accompli?
    Will have to widen back entrance to get the Lethal Insect's main hull out. Here's very early stage. Wide on deck, narrow waterline. Contortionist skills required in the tight confines while construction commences.
     

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  12. oldsailor7
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    oldsailor7 Senior Member

    Wow! That really is a "Tight" space. :eek:
     
  13. Gary Baigent
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    Gary Baigent Senior Member

    20mm lens makes it look coffin-like. Is not so bad in reality.
     
  14. Gary Baigent
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    Gary Baigent Senior Member

    Here you are OS7, about as much room in my 2 into 1 shed as down below in Sid. Gifford says all my boats are like living under a table. But anyway some more progress. I know, I know, once you design one boat, all the rest look the same.
     

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  15. patzefran
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    patzefran patzefran

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