Has anyone ever sailed a catboat with a balanced rig?

Discussion in 'Boat Design' started by misanthropicexplore, Jul 9, 2018.

  1. misanthropicexplore
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    misanthropicexplore Junior Member

    I don't really care if it was a balanced lugsail, a junk rig or a balestron. I just wonder if the balanced rig undoes the lack of pointing caused by the lack of a jibsail.
     
  2. messabout
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    messabout Senior Member

    Absence of a jib sail is not the determinant for pointing ability. Monosails of the right sort can go to windward very well. The typical rig on a classic catboat is not particularly good at windward work. It will certainly go to windward but not like some of the more sophisticated mono rigs.
     
  3. philSweet
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    philSweet Senior Member

    The catboat has a problem transferring heeling torque to the boat because there isn't much of a box beam structure to work with right up in the bow. So the running rigging tends to be designed to relieve the mast of some of the heeling moment. This is exactly the opposite of what a balanced sail is intended to do - namely transfer all the strain to the mast and ease the running rigging loads. Look at the layout of the traditional working luggers. The masts are set back a fair bit and well stayed.

    [​IMG]
     
  4. misanthropicexplore
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    misanthropicexplore Junior Member

    Ah, that makes perfect sense.
     
  5. misanthropicexplore
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    misanthropicexplore Junior Member

    So would a torsionally stiff catboat with a rigid mast has basically the same windward performance as a sloop? The mast forward nature itself, and/or the lack of a jib isn't the real issue?
     
  6. philSweet
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    philSweet Senior Member

    There are some practical concerns, but there isn't really any physical reason why not. At least not on a smooth sea in good, stable air.

    The ride tends to be rougher going to windward cutting waves; and a mast up in the bow is going to bounce around more than one nearer the middle. These perturbations detract from performance. More weight and inertia forward don't help either.

    You also have to worry about where the sail's fore/aft center of effort is. In order to get it far enough aft, you either need a divided rig and mizzen mast to be able to use high aspect sails, or you need a low aspect rig on one mast. Neither can compete with a high aspect sloop in absolute pointing ability - Not that it matters much except on the race course.
     

  7. LP
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    LP Flying Boatman

    A balanced sail does nothing to improve pointing due to the lack of a jib (headsail). Pointing is typically improved with a higher aspect rig and balanced sails tend to be of lower aspect ratio. The head sail improves the efficiency of the rig or more correctly, the mainsail improves the efficiency of the head sail. With these gains in efficiency, pointing can be improved.

    You also have some losses with a balanced sail as you have the "bad tack" where the lift producing, leeward surface is dirtied by the mast.

    You didn't mention split rigs which are commonly and/or sometimes associated with balanced type sail plans. There are also pointing losses associated with these plans which may be outside the scope of your questioning.
     
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