How do I control both sheets from one rope?

Discussion in 'Sailboats' started by miniman, Jun 8, 2009.

  1. miniman
    Joined: Jun 2009
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    Location: scotland

    miniman Junior Member

    Hi all,
    I hope someone can help me out here.

    I own and sail a 23 foot keelboat, called an "E-Boat" See this website for more info--- http://www.e-boats.org.uk/

    I sail her on my own most of the time, as I can't get regular crew, and in im a very isolated area of Scotland.
    I mainly sail her on just the mainsail because she is quite tender, and the need to play the sheets to keep her on her feet is important.
    I have now cut down an old genoa, and im making a self tacking jib, on my own design boom, just the same as the RC race yachts.
    This will hopefully allow me to use a smaller jib when im out sailing, and hopefully get a bit more speed/fun.

    I will sheet the jib using one single sheet, round a block at the mast base, and back to the cockpit. This means less hasstle for tacking etc singlehanded on a tender boat.
    This will still require me to use two sheets,(one for main, and one for jib) but I'd prefer to have just one rope in my hand to work both sails sheeting, leaving the other hand for the tiller!!:)

    Any ideas how I can rig this to get it to work, or any better ideas to make my sailing more easy?
    Remember the tight Scotsmans budget as well please!!!;)

    Thanks.
     
  2. PAR
    Joined: Nov 2003
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    PAR Yacht Designer/Builder

    The EBoat is a performance lifting keel sailor. It's not especially tender for her class. She'd does best if sailed flat footed as you've gathered.

    Reducing the size of the headsail will not improve performance, but will decrease it a substantial amount. Cutting down an old genoa to become a 90-95% boomed jib, requires the panels be recut or the draft of the sail will be too far aft to set well in it's new configuration.

    As far as the sheets, you could rig up a proportional cascade sheet system, but it would be problematic at best. As you likely know the jib will not trim in or out the same as the main, so a cascading type of system is required, but figuring out how much will be daunting to say the least.

    You have to trim each sail one at a time anyway, so trim the jib, cleat it, then trim the main. Once trimmed properly, steer to your tell tails so you don't have to fool around with the sheets much. When single handed I usually steer to the mainsail and trim the jib or just steer to the tells. This keeps the boat in the groove, moving well and you're not playing sheets like crazy.
     
  3. Doug Lord
    Joined: May 2009
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    Doug Lord Flight Ready

    The Swift Solo singlehanded trapeze skiff uses a main and jib rigged to one sheet. It has the facility to adjust the slot separately. Great system and I used it on my first foiler. I'll see if I can find a sketch or you might google the Swift Solo class association to see if you can get a copy. It was also published in Sailing World around 2002. I'll get back to you if I find anything... I found it-click on image:
    Here is the text:
    ------------------------
    Self-tacking, self-trimming jib system-designed by Bram Dally-fromDecember 2001-January 2002 Sailing World

    A jib system that's self tacking and trims along with the mainsheet has many benefits that could be applied on other boats. The jib and main remain synchronized when eased for gusts or for reaching. The self-tacking jib is of proven value on most of Bethwaites skiffs and the synchronized-sheeting feature is not difficult to install. The mainsheet/jibsheet is led from the trimmer's hand directly to the boom block and cleat, turns forward to the mast where it turns 180 degrees through a ratchet block and enters the boom. It then splits with one end going out the aft end of the boom to the transom bridle. The other leg goes to the aft end of the boom and turns 180 degrees back to the mast where it turns downward to the foot of the mast and then forward to a standard 49er jib sheeting system. The jib "relativity" control system, or fine tune, is used to set the main and jib for various wind conditions.
    Synchronization between sails is largely a function of the bridles triangular base and height, and the purchase of the two systems.
    Because jibs are cut differently on various boats, I can't provide any hard and fast formula, but with a little high school geometry and trigonometry you can figure it out.
     

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  4. gggGuest
    Joined: Feb 2005
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    gggGuest ...

    Before you go to all the work of making a jib that adjusts with the main I suiggest you try without... The combined system has been tried quite a number of times on International Canoes and always abandoned as providing no benefits: with a blade jib it sees to be better in most circumstances to have it sheeteed consistently rather than played, at least in smaller boats.

    If you do decide to have one the Swift Solo system is probably a good bet.
     
  5. Doug Lord
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    Doug Lord Flight Ready

    I think this system can be modified for use on mid boom sheeting system and by sometimes controlling the main with the traveler it can be adjusted w/o adjusting the jib. I'm about to find out but I haven't tried it yet.
     
  6. wet feet
    Joined: Nov 2004
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    wet feet Senior Member

    I discussed this concept with a friend in the early eighties.What we arrived at was the possibility of using the principle of drawing an ellipse using a piece of string wrapped around two pins.We proposed using a loop of rope passing round the mast to an adjustable block on the underside of the boom.The forward end of the loop would have been connected to a single rope passing through a block on the foredeck and attached to the jib boom.The operation would have involved adjusting the attachment points on the jib boom and main boom to establish the correct ratio of adjustment and when optimised,hauling in the mainsheet would simultaneously bring in the jib.If it was felt necessary to revert to individual control of the jib,we would have run a line from the block on the boom aft for a distance and then taken it into the boom and forward.At the forward end of the boom we would have brought it down to deck level and to a swivelling cam cleat.
     
  7. miniman
    Joined: Jun 2009
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    miniman Junior Member

    Thanks for the words of wisdom guys.
    The jib I have cut down and re-sewn is an old reefing jib, with the max camber set well forward anyway, and a high set clew. Ive been using it for the last year, giving good results. You must also remember that im not racing, or pushing for max speed. Im just out for the pure enjoyment of sailing.
    Im still going to be trying out the boom concept, and a seperate single sheet for the jib. This will make it easy for me to play the jib if needed, and also make it easier to tack singlehanded.
    The wind here in Northern Scotland can be very gusty, and certainly very unpredictable, hence the need to play the sheets. I must admit to also being a little nervous about heeling over too much. Ive heard all these knockdown stories, especially about the E-Boat (since I have one!), and it continually plays on my mind.
    I once got the genoa clew caught on the spinnaker boom mast attachment during a tack, and she heeled way over, scaring me a wee bit. My crewman had to go forward and un hook it very quickly. Maybe this is the source of my worries!!??
    When I have a crew member, I use the full genoas to full effect, and the E-Boat is a great fast wee boat. I have so far had her doing 9 knots on a beam reach, and it was fun!
    Im going to have a better look at the swift solo arrangement and see how I get on.

    Thanks.
     
  8. EdgewaterMD
    Joined: Jun 2009
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    EdgewaterMD Junior Member

    I misunderstood your question -
     
    Last edited: Jun 14, 2009
  9. miniman
    Joined: Jun 2009
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    Location: scotland

    miniman Junior Member

    Hi all,
    I have now made up my jib boom, and have it ready for initial trials.
    I am still having a few issues with the kicker (vang) , as the clew is so high, the boom is also at a high angle, and the normal kicker is just no use. I cant get the downward purchase that it needs to stop the boom lifting. (But maybe thats good in the gusts!!?)
    I was thinking of trying a rope track, with the sheeting point to a pulley that can slide accross the deck, and see how that works out.

    Any other ideas? It does look as if two sheets instead of three is the answer though!
     
  10. gggGuest
    Joined: Feb 2005
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    gggGuest ...

    Back in the day the standard arrangement for a jib boom was to have the take off down to the deck fitting a fair bit back from the sail tack so that the halyard load went partly down the leach and no kicking strap arrangement was necessary.
     
  11. miniman
    Joined: Jun 2009
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    Location: scotland

    miniman Junior Member

    Aye, We do the same with the model racing yachts.
    I will have to have a better look at how she is rigged. The tack is set very low, in a recess in the bows, but im going to have to raise it up anyway so that the boom will clear the handrail better.
    I have added a stainless ring-bolt onto the boom to try moving the tack pivot point already, but havent been down to the boat again to try it out yet.

    Cheers.
     
  12. miniman
    Joined: Jun 2009
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    Location: scotland

    miniman Junior Member

    Hi Guys,
    I have now got a fully operational self tacking jib on a boom!
    The kicker problem was solved by using the sheet as a horse!
    One end of the sheet was tied to the stbd toe-rail, and led through a single sheave block on the aft end of the jib boom. This in turn led to another block on the port side toe rail, and off to the cockpit for sheeting control, creating a slack rope horse.
    The more the wind pushes against the jib, the more the leech is pulled down by the rope horse. The adjustment is great, and sheeting control is perfect for me sailing single-handed on those windier days.
    I was out testing it the last two days, and im very impressed with its operation.
     
  13. Crag Cay
    Joined: May 2006
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    Crag Cay Senior Member

    Good news, but just remember to keep those washboards in and think of sealing the centre board case!
     
  14. miniman
    Joined: Jun 2009
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    Location: scotland

    miniman Junior Member

    Aye, the lower wash-board has been glassed in place, and is now the mount for the compass/instruments! FAR safer!
    As for the keel case, it is watertight. I made up a new keel top-pan, and fitted a foam-rubber gasket round the edges. The case can now pump dry and stay that way all season!
    She also has foam flotation added, much more than necessary.
    I do use her in days that would make most E-Boat owners cringe, but I must say that she is a good dry boat in all but the worst days.

    Cheers.
     

  15. miniman
    Joined: Jun 2009
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    Location: scotland

    miniman Junior Member

    My next job is to make a better/more watertight hatch. The top washboard has already been renewed, and it seals tight against its own gaskets. The original sliding hatch/garage could do with being beefed up a bit though, and made more "Scottish weather proof!"
     
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