How much travel does a Traveler need?

Discussion in 'Multihulls' started by Jetboy, May 27, 2015.

  1. Jetboy
    Joined: Feb 2012
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    Jetboy Senior Member

    I've been asking a lot of rigging questions lately and I have another. How wide must a traveler be to work properly and be useful?

    I've got a traveler track that's about 72" long. And I can either mount a 28" section of it directly on the cross beam in the rear of my trimaran, or I can make aluminum risers, add a support beam, and mount the traveler in full width. What would you do in my scenario?

    Here's a pic of the rear beam to give you an idea of where it would go.
     

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  2. waikikin
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    waikikin Senior Member

    Hi Jetboy,

    Well, travellers can never be too long, but they can be too short... so within a greater range of positioning options combined with sheet tension a a joyful symphony of sail control can be achieved, this will tell the tail & should be the leech of your expectations.

    Jeff.
     
  3. gonzo
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    gonzo Senior Member

    The perfect traveller would be an arc of a circle that allows the sheet to always be vertical.
     
  4. John Perry
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    John Perry Senior Member

    does seem a pity to have a 72" traveller then cut it down to 28". Looks straightforward to mount it onto the side decks. Is it too late to cut away/recess the side decks so that it could go directly onto the aluminium tube right across with top of traveller about flush with side decks? How will the tiller/tiller extension interact with the traveller/mainsheet - will there be an ergonomically satisfactory helming position sitting aft of the rear cross beam and will this allow in a suitable length tiller? Hard to tell from the picture. Many of the Farrier trimarans have the traveller on a sort of elevated 'bridge' so that the tiller can swing underneath the traveller and the helmsman sit forward of it, but that might look ugly on your boat. Alternative could be to have the tiller pivoted somewhere near, or on, the aft beam and link it to the rudder through two levers joined with a push/pull bar. Just thoughts. Looks an interesting trimaran.
     
  5. Jetboy
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    Jetboy Senior Member

    I had intended it to work something like the astus 18.2 with a curved tiller arm that goes over top of the traveler.
    [​IMG]

    It's probably pretty late in the process to modify the seats, but I have the tools to weld aluminum so I can make a few brackets and add a section of some smaller tube to run along the top of the seat decks and tie structurally into the cross beam for additional support easy enough.

    After reading the responses I think this is my best course of action to create the best sail control options. And it will tend to move the traveler car further off center making room for tiller movement. Unfortunately it will still require the tiller be moved around the sheet like you do on a beach cat. I had kind of anticipated that being required, so not really a big deal.

    The picture might be deceiving. This is only an 18' long trimaran so seating position is kinda important to balance of weight. I intended to steer from a seat position ahead of the cross beam most of the time.
     
  6. pogo
    Joined: Mar 2010
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    pogo ingenious dilletante

    having a straight traveller , u can add a track under the boom to compensate.

    Have a close look, notice the straight 6m traveller track and the 1m black track under the boom :

    http://imageshack.com/i/3qtt025j

    pogo
     
  7. tom28571
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    tom28571 Senior Member

    Just about "that much". Maxwell Smart
     
  8. rcnesneg
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    rcnesneg Senior Member

    Full width definitely. I would say for your boat, 8 feet would be perfect, but since you can't do that, just do as wide as you can get it without it interfering with the folding/separating/whatever system.
     
  9. daiquiri
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    daiquiri Engineering and Design

    As rcsneg said, the maximum you can get without interfering with other systems, like tiller.
    A long traveller will give you a wide range of trimming possibilities, while a too short traveller will put a lots of load on sheets and on the deck structure. You can use this guide by Harken to calculate loads on your traveller system: http://www.harken.com/article.aspx?id=16233
    Cheers
     
  10. waikikin
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    waikikin Senior Member

    I concur, this is an ideal compromise & can leave the control lines much tidier than the "perfect arc" scenario, although I'd opt for the simplicity of a round boom strap arrangement that acts to clew/outhaul/mainsheet & also ideally strikes an average behind/in front of traveller track at mid/set down settings..
    Jeff.
     
  11. Jetboy
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    Jetboy Senior Member

    I've got two booms for this boat. Not sure what to use yet. Planning to go with the Nacra 5.2 boom. Oddly enough It has a traveler track on top of the boom for the outhaul on a loose footed main sail. I don't totally understand why you'd want that rather than just use a normal outhaul?

    So it would be pretty easy to just swap that to the bottom of the boom and have a 18" or so traveler on the bottom of the boom. It's the same extrusion and car as the main sheet traveler.

    My intention longer term is to have a new set of sails made and go boomless. Much like the F22 is. I think particularly for that scenario a long traveler may be more useful as well.
     
  12. teamvmg
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    teamvmg Senior Member

    There's nothing like the feeling when you ease the traveller in a gust and feel it hit the stop when you would rather it kept going!
    The trailering width of the boat is your limit.
     
  13. aussiebushman
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    aussiebushman Innovator

    Gonzo is surely right about the arc arrangement - that is precisely like the one on my old A-Class.

    I'd like to use that track on the new inshore cruising catamaran but I would want to include a system to control the position of the car - the arrangement I have used before (see picture). Has anyone worked out how to add control lines to a curved track? Those lines would require some complicated geometry and probably get in the way of the tiller and aft cockpit seat
     

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  14. tspeer
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    tspeer Senior Member

    Instead of a traveler, my cruising tri has a block mounted at the end of each beam. A continuous vang/preventer goes from the boom to one block, across the boat through clutches on the inboard ends of the beams, out to the opposite block and back to the boom. Being continuous, it minimizes the extra tail in the cockpit. The mainsheet goes to a block fixed on the centerline.

    One pulls on the leeward vang to reduce the twist in the mainsail. It's kind of like a Cunningham for the main. If you need to to ease the main, you can do that with the sheet and it will twist off the head as well. But one does need to ensure both clutches are open when jibing.

    You could do a similar arrangement on your boat, with cleats mounted to the gunwale near the aft beam. It would be lighter and cheaper than a traveler, and allow you to control the twist over the whole range of motion of the boom.
     

  15. tspeer
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    tspeer Senior Member

    It pulls down on the clew as the outhaul is eased, so the clew moves horizontally along the boom. Otherwise, the clew will rise up and change the twist.

    It also reduces the load on the outhaul significantly, making it possible to adjust the outhaul much easier. The track reacts most of the leech tension, and only the horizontal component of the load has to be taken by the outhaul.
     
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