Boomless Gaff "Wharram type soft wing"

Discussion in 'Sailboats' started by mark in nj, Jul 26, 2006.

  1. mark in nj
    Joined: Jul 2006
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    mark in nj Junior Member

    Boomless Gaff: Do I need a boom?

    I began experimenting with boomless sailing last weekend between races on my Lightning Sailboat. It actually seems to work pretty well for just cruising around. I had it sheeted to the stern spinnaker gear at about 45 degrees from the clew, and could move the sheeting from port to starbord.

    Anyway, as I said, it seemed to work pretty well, and I am considering playing around with this concept on my cruising boat: Sovereign 17 (similar to Com Pac 16).

    The main behaved kind of like a big jib, boomless during my test, but I realized that it may not be that good going downwind because it may kind of collapse and flop around without a boom or wisker pole to hold it out.

    Annyway, I was thinking a gaff rigged sail may work better on different points of sail, because the gaff will hold the sail out to the side downwind. I am thinking of trying to make somethig with a small gaff, like a "Wharram type soft wing" with the exception of it sliding it onto a regular aluminum mast with a luff rope in place of his wing mast sleeve.

    Boomless looks like a-lot of fun for cruising around, without ever having to worry about the boom hitting you in the head, or rigging a vang, and depending on how you do your downwind work, there may not be any accidental jibes either.

    So, what do you all think of my boomless ideas.

    Mark M from NJ USA
     
    Last edited: Jul 26, 2006
  2. messabout
    Joined: Jan 2006
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    messabout Senior Member

    Boomless mains have a definite attraction to those whose head has met a boom in an unkind encounter. There are some boomless sails that have one or two full length battens positioned in the lower third of the sail. That seems to work pretty well. The battens also help stack the sail when dousing it.

    Another scheme with more merit than it is generaly accorded, is a sprit boom rig. The simplicity of it is most welcome for casual sailing. There is only one string to adjust( the snotter) and you can make the sail full or flat at your pleasure. The boom intrudes into the cockpit only at the clew end. The disadvantage is that there is a good tack and bad tack when the sprit contacts the sail. In my experiece the bad tack does not do as much harm as one might presume. This is probably not a preferred rig for passagemaking as chafe can become a factor. For casual sailing it's no problem.

    You can tinker with the sprit rig by using a jib in place of the main. You need a light air jib to fiddle with this notion. The light air jib will have less negative luff allowance, so it will set better than a jib cut for heavy air.
     
  3. mark in nj
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    mark in nj Junior Member

    boomless

    I for one think boomless is worth a shot. A jib is a usefull sail, and what is a boomless main other than another jib with a vertical luff. That is my $.02

    Most "cruising types" only cut the motor if conditions are completely ideal. Who are we fooling anyway, and who really drives their corvette at 135.

    I see no problem with a less than perfect rig if you aren't racing, and enjoying it. Everyone should take a look at historic and international boat design to realize that the marconi sloop is not the only way to move a boat through the water with wind power.

    Mark
     
  4. Crag Cay
    Joined: May 2006
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    Crag Cay Senior Member

    Boomless mainsails have a problem. If hit by a gust, it's sometimes handy to be able to 'dump a bit of mainsail' by cracking the mainsheet. With a well vanged boom this quickly depowers the main and the boat comes back on its feet. With a boomless main, slacking the mainsail causes more camber to develop in the sail and therefore become more powerful, just when you were hoping for the opposite.

    Bascially, boomless only really works when the mainsails leech is as vertical as possible. Sprits are perfect for this, as are gaffs. They also help hold the sail out when off the wind.

    Where the leech runs forward (eg, windsurfer / Freedom bermudan or Nigel Iren's Lug) you need something else to stop this powering up. It's the wishbone on the original Freedoms and several full length battens in the lower part of Nigel's sails that achiev this.

    The Wharram soft wing would not appear at first sight to have a long enough gaff to work well in this regard, but remember they are fitted to catamarans where even a simple block out on the gunwhale can be effectively used as a traveller to maintain foot tention whilst opening the leach.
     
  5. dskira

    dskira Previous Member

    You have a very good point.
    I like the boomless on a gaff rig, with the gaff quite horizontal, and a vang controling it.
    The leech being quite vertical.
    It is easy to reef, can be brail against the mast in no time.
    I find it very flexible. As for the head, carefull of the heavy blocks at the clew flying over on a tack, can be deadly. But the people comming out of the companionway are safe on a boomless, which is very good thing.
    Cheers
    Daniel
     

  6. david@boatsmith
    Joined: Aug 2008
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    david@boatsmith Senior Member

    Gosh the only real reason to have a boom is to control sail shape. Learn to control sail shape and you will sail more. Our current cat is a Wharram Tiki 30 with the luff pocket gaff wing sail. The two new cats we are building we have bought full battened big roach mains with booms. No boom means very little control over sail shape. We joke that if the main is up it's trimmed. It doesn't get trimmed by inches, it gets trimmed by feet. Plus it's easy to stow a sail on a boom as opposed to wadding it up into a bag. My nickels worth. David www.boatsmithfl.com
     
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