Biplane rigs

Discussion in 'Multihulls' started by cutawaycafe, May 15, 2013.

  1. cutawaycafe
    Joined: May 2013
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    cutawaycafe CutawayCafe

    I know that Bernard Rhodes tried a biplane rig for his cat 'Flying carpet'? and there have been a few others before and since.

    But has anyone on this forum sailed a biplane rigged cat and have an opinion? And/or, does anyone have an opinion on what seems to me the best aspect - the de-stressing of the centre of the crossbeam by placing the masts outward.

    In my own design, I'm considering the masts as pivoting on a point obove the main crossbeam but on the very inside of each hull. This to provide as much lateral distance as possible for the outer shroud while still allowing the force of the mast to sit on the hull/beam, and not beam alone. Also, in place of a inner shroud to have a solid brace across from mast to mast.

    Thanks, Dan
     
  2. Corley
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    Corley epoxy coated

    Do a search on the forum members list and contact via pm the member cat2fold he has a biplane rig on his folding catamaran and seems to like it.
     
  3. Gary Baigent
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    Gary Baigent Senior Member

    Only have experience on trimaran but very much the same thing as catamaran in that the masts were placed proportionately apart similar to a catamaran's beam.
    Malcolm Tennant drew a 6.5 metre cat with bi-plane rig with them set on the beam but on the outer gunwhales (you need to get as much width apart as possible) - also if the boat got knocked over, the sealed masts would stop it inverting.
     

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  4. redreuben
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    redreuben redreuben

  5. Cat2Fold
    Joined: May 2012
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    Cat2Fold Junior Member

    Cat2Fold's Biplane rig

    Yup...I absolutely love my biplane rigged cat.
    It is SO easy to sail! It has a very low center of effort. I always feel very safe.
    Is it the perfect sail plan? No. There are pros and cons to everything.
    Is my boat gonna fly a hull at 20 knots like I watched the Sig 45, Vamanos!, do during the Banderas Bay Regatta? Nope.
    Has my boat ever given me the feeling like we might fly a hull and/or flip over sideways? Not even in the slightest.
    Does my boat easily do 10 knots in absolutely dry, comfortable conditions all the while feeling safe, having a HUGE view forward and aft, great views of the sails, with no sheets to pull while tacking upwind? YES!!!
    Speaking of upwind, Cat2Fold goes to weather better than almost any boat I've sailed with/against.
    I couldn't be happier with my decision to own a biplane rigged cat.
    Now if I could only find a sponsor/financier to help fund the building of some soft wing sails. I have the vision...just no money. :(
     
  6. Herr Kaleun
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    Herr Kaleun Junior Member

    So what are the opinions on a schooner biplane using free-standing wing sails?
     
  7. cutawaycafe
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    cutawaycafe CutawayCafe

    'A schooner biplane using free-standing wing sails'. Could take it further and add 'footless' (if that would be an adequate way to describe a wishbone arrangement? Or not?)

    I was not planning on going stayless, but am open to the idea (if the materials can stand it safely)

    Very much liking the comment on sealed masts providing an anti-turtle function. With four, this would be more.

    No 'experience-led' comments back yet on four masts.

    I'm very interested in how much sail area could be achieved and how short the masts may be. My whole purpose is to reduce the chance of capsize, regardless of the sea state and wind. The cat I am planning will be much lighter than a cruising cat. I am not intending to race, but want to have a good turn of speed possible when (for example) there is weather to be avoided.

    I also realise that when living aboard, the vessel is stationary for the vast majority of time. Having four masts at four corners of an open bridgedeck sounds, well, practical in so many ways. They could offer internal fresh-water storage with pressure. Four points an awning could be slung from. Hammock points. Four points for support of solar panels across the main space.

    And at sea - redundancy in case of mast failure. Lower CoE. More sail configuration options. Imagine a goosewinged cat downwind, sails out and in.

    The price is complexity, when under way. That is the main factor to consider.

    Very positive to see the biplane comments so far!
     
  8. Herr Kaleun
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    Herr Kaleun Junior Member

    Well dude, thats why I'm here... Coz I want to design a rig along those lines, yep loose-footed maybe, but imagine if the sails were made of solar photo-voltaic fabric as well[!?!], I'm working on it...

    In fact I have loads of old insulating block foam and I will be building an RC model of the vessel to see how the concept pans out [kinetically]. Will test it on a local reservoir which is used for sail training and well choppy at times.

    The idea came to me, as they do[serendipitiously...?] , by realising that I wanted a decent [frigate style] bridge/wheelhouse, which would be a problem on a standard schooner cat [Like the Wharrams Islander class, which has quiet low, loose-footed wingsails and dumpy little masts.], then I realised that the biplanar rig was possibly the answer. Like having twice the boat for almost the same money, by having a cat, having four wing sails will surely add to the energy factor [make em SKS and even more so...].

    Then add some trick hybrid engineering [for when the wind drops...] fed by those SKS sails/fuel cells/DE system and away you'll go.

    Every Little Helps...
     
  9. Herr Kaleun
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    Herr Kaleun Junior Member

    You mused over the cat downwind in goosewing config, then add the square spinnaker between the two foremasts... In fact I thought tonight, that one could construct a lightweight [carbon fibre comp] catwalk between the masts, that could hold antenna, small aerogens, radar, even a lookout...] And no, I don't think I'm taking this too far... You gotta push the envelope when designing, but above all communicate in open-source attitude, thats why we're here, I would hope...
     
  10. ImaginaryNumber
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    ImaginaryNumber Imaginary Member

    A disadvantage with any multi-sail sailboat is that on certain points of sail one sail will adversely blanket another sail. With a tandem biplane sail configuration it seems there would hardly be any point of sail in which at least one sail wasn't being blanketed.
     
  11. Corley
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    Corley epoxy coated

    Michael has just launched his Schionning Wilderness 1230 with bi rig. Freestanding carbon rotating masts. The slight bow down trim is caused by the amount of gear from the build still in the front of the boat awaiting use and clean out.
     

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  12. RHough
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    RHough Retro Dude

    I'll vouch for C2F's upwind performance ... it is damn near jaw dropping for mono-hull guys.

    Great boat and great crew.

    R
     
  13. Gary Baigent
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    Gary Baigent Senior Member

    In reality, IN, not so. On Misguided Angel the only time the leeward rig was slightly blanketed was on a true 90 degrees AW reach ... and to counter that you either head up or down only a few degrees.
    Talking about two una rigs with wing masts on a fast and light boat here, which always dragged the apparent wind forward. On such a boat, you can virtually say blanketing doesn't exist.
     
  14. cutawaycafe
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    cutawaycafe CutawayCafe

    I am so in favour of practical experience speaking. Thanks Gary. Very keen to hear ideas and then hear who has tried it out. Even if they failed. Or not :)
     

  15. T0x1c
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    T0x1c Junior Member

    The carbon masts for the Schionning Wilderness 1230 have costed 70 kAUD (booms excluded?)
    Even if they work well, I think it is enough to understand why we don't see more of them.
     
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