affect of mast on offset sail

Discussion in 'Sailboats' started by Timothy, Mar 3, 2009.

  1. messabout
    Joined: Jan 2006
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    Location: Lakeland Fl USA

    messabout Senior Member

    The mast and offsetting components on the Hoyt rig gotta be hell for strong. He has a nightmarish set of forces in play, what with cantilevered attachment points and resulting bending load on the mast, in addition to compression load. Add the torsional load to the poor mast while we contemplate the structural requirements.
     
  2. Autodafe
    Joined: Jun 2008
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    Location: Australia

    Autodafe Senior Member

    The Hoyt rig does seem a step backwards structurally.

    I've been toying with an offset junk rig, where each batten is offset from the mast by a half wishbone yard. Think dynarig offset to one side a bit and used as a fore and aft sail.
    The use of yards as well as battens is to improve the often poor sail camber of junk rigs. The yard holds the ends of the battens, which now exist only to maintain the sail shape in light air.
    I am tempted to use the mast to take torsional loading, as this eliminates the traditionally complex sheeting arrangement on junk rigs. It does make twist adjustment hard though.
     

  3. masalai
    Joined: Oct 2007
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    Location: cruising, Australia

    masalai masalai

    How about this from John Hitch - a boat he designed and built called "X-IT"... In a chat about his sail plan and how it worked in summary, both main genoas work on every point up to about 35 deg into apparent wind - - EXCEPT 90 deg apparent (dead beam on) - so to fix that, pull up a little into the apparent wind and as speed picks up, you make better vmg to the mark... Wind over 13knots, start reefing windward, then leeward genoa, leaving the little fully battened "blade/storm-sail".... Never sail downwind head off about 30 degrees and go a lot faster in vmg downwind... - I think I have that bit down OK.... seems like a very easy rig to manage, and very effective and very simple.... Just what I want...

    John's boat is nice, yes?... about 52 ft loa, 32 ft beam, hulls are 2 ft wide.... he sails single handed - pretty good at 67YO, and boasts a top speed over ground of 23.99 knots....
     

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