mini schooner dinks

Discussion in 'Sailboats' started by nota, Sep 28, 2012.

  1. nota
    Joined: Sep 2012
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    nota Junior Member

    I am building my second dink schooner
    on a cape dory 10 copy hull

    I had a 16 ft ply rowboat that I rigged as a schooner
    my trick is to sheet the top of the foresail to the main mast
    a local rigging shop owner commented a small rig can do that
    BUT it will nor scale up as the force on the main mast top is too big

    no jib was used bald headed schooner dink

    the top sheet cuts the twist to a minimum on the foresail
    I use a ripped up main bottom for the foresail
    just turned the boltrope across-ed the top of the sail and sheeted to the main mast
    bottom of the foresail had a small lap on the main
    and was the only sheet that needed to be handled on a tack
    no booms gaffs or battens just two sheets on the foresail
    with no adjustments to the top sheet on a windward tack
    it could be eased to run or reach

    the boat was use as a dink to get to a anchored liveaboard vessel
    and pointed very well and was fast for a dink

    anyone seen a similar rig in use ?
    or how big can such a rig be
    before the force on the top of the mainmast gets tooo big ?
     
  2. Doug Lord
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    Doug Lord Flight Ready

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  3. nota
    Joined: Sep 2012
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    nota Junior Member

  4. sharpii2
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    sharpii2 Senior Member

    Is the top sheet holding the top corner of the sail up?

    If so, adding a sprit to hold the top corner up would improve the rig dramatically.
     
  5. nota
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    nota Junior Member

    yes

    why
    the sail curve is controlled by tension on the upper sheet
    now off the wind maybe it would project more
    but going to windward NO
    plus weight aloft and more strings drag ect
     
  6. sharpii2
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    sharpii2 Senior Member

    Because, as you let out the 'top sheet' (peak vang). The peak will sag downward, causing the trailing edge to to bow out to leeward, destroying any decent sail shape. Much of the sail would be simply fluttering to leeward like a flag. Pulling it in with the sheet and peak vang will have the upper and lower corners of the sail sheeted in too far, so they are flat to the wind. Either way, you may end up with a lot more drag than driving power.

    With the peak held up with a sprit or gaff, the only way it can move is sideways. In other words, the sprit or gaff keeps the trailing edge of the sail (the leech) reasonably straight.

    If you don't want to bother with a sprit or gaff, you can treat your peak vang as a halyard. Just leave it snugged up and only let the bottom corner of your sail (the clew) out. Doing this turns your foresail into a 'fisherman's stay sail'.

    Not very efficient, as a 'fisherman's stay sail' needs to be designed as such, but probably better than what you have in mind.
     
    Last edited: Sep 28, 2012
  7. nota
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    nota Junior Member

    well maybe the first boat got very lucky
    or a little sag gives a fuller sail off the wind
    but I can report it worked fairly well
    perfect maybe not BUT

    IT WAS AN ALL WEATHER GET BACK OUT TO THE BOAT RIG
    THE BOAT RAN AND REACHED WELL
    AND POINTED VERY WELL MOST IMPORTANT
    FOR A GET BACK HOME RIG
     
  8. sharpii2
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    Location: Michigan, USA

    sharpii2 Senior Member

    Thanks, Doug, for showing me this. This is the kind of innovation i like.
     
  9. sharpii2
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    sharpii2 Senior Member

    Was the fore sail for your 1st boat cut flat?

    If it was, that could explain some of your success. As an originally flat sheet, it's more likely to form a cone section, not a bag, as the top and bottom corners (the Clew and the Peak) sag towards each other. That's the same kind of shape i would be looking for, if I tried designing a fisherman's.

    Even if you are getting maybe slightly better half as much drive out of the sail as you could by using a sprit. Slightly better than half is better than nothing. And you don't have to mess with the sprit (yet another spar).

    It would be an interesting experiment to try the rig with and without a sprit and see just how much the sprit improves things.

    If the sail is just a flat sheet, the improvement may be quite modest. Maybe 60% vs 50% efficiency. But that's only as a flat sheet. With the sprit, it may be possible to give the sail some 3D shape, by taking out a dart in a strategic location. Then the improvement made possible by having the sprit might be 75 to 85% efficiency.
     
  10. nota
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    nota Junior Member

    sail was an old mizzen that had ripped
    I just sewed the boltrope across the top
    and tied that to the halyard

    on that boat the main mast was a bit higher then the top clew on the FS
    so no real sag was noted

    I may use a full upper batten on the 10ft boat
    did make a pocket sleeve when I sewed the sail for one

    major problem at the moment is finding bronze flat stock
    to make seat brackets [I could use SS or al but like the look of bronze]
     

  11. Doug Lord
    Joined: May 2009
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    Location: Cocoa, Florida

    Doug Lord Flight Ready

    ================
    You're welcome!
     
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