Latest News: Forums Technical Efficient Use of Jib as Alternative to Genoa Luff Spar

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  • #4433
    Fundoctor
    Member

    Dear Farers

    Attended the recent Cruising Conference and working through the aftermath for boat and bank account. One general view seemed to be need to get luffspar to allow reefing of genoa. My Wayfarer mentor (Chris Yerbury) has always cruised with a furled jib fixed to his foredeck. This and the genoa have gated hooks which quickly swop on the wire halyard when it is time to reef (the genoa remains in position furled on foredeck). My boat came with a nearly new jib and I am keen to try out Chris’s system before investing in spar kit. Two questions then:

    a) Do people have experience of this jib system and is it OK and any suggestions for refinement – main concern is speed changing the sail.
    b) Chris has D-rings bolted to the wave-cheater thing on the foredeck that lead the jib sheets back to the jib cleats at a more advantageous angle. (Attempting to attach photo of same from another boat). My boat is 3-way owned and very hesitant about attaching anything without very solid reasons. Do these d-rings make a real difference to jib efficiency and if so where is the best place to put them?

    Many thanks

    Trevor
    W9002 (Mk2)

    [attachment=0:1wxetqe9]197.jpg[/attachment:1wxetqe9]

    #10803
    Bob Harland
    Participant

    We have never had a “luff spar” on the genoa. We carry a genoa, jib, and often a storm jib.
    It does take time to swap over headsails and it is a job for the strongest crew member.
    I think the most difficult part is hoisting the new sail – particularly the last bit when you have to get the wire halyard eye over whatever tensioning device you have.
    Having the spare sail ready tacked on the foredeck helps a bit – but however you do it there is no getting away from the hoisting the sail.
    There is a small performance hit of the luff spar – under full sail I find we can steadily pull away on a beat. But otherwise it is easy to see why the reefing luff spars are popular.

    For the jib sheet lead it may depend on your boat and sails. We have always use the same genoa sheet lead – perhaps adjust the position of the block on the sliding track, but that is all. If that is not enough you could consider a short wire strop on the tack – and reduce the length of the wire strop on the head. (that’s assuming you have a wire strop there).

    If you are going to be swapping headsails underway then do go and practice in some sheltered waters on a quiet day first.
    hope that helps.
    bob

    #10804
    Swiebertje
    Participant

    I have made some quick sketches to explain the extra sheet fairleads on the breakwater.

    Let us assume that the mean position of a fairlead is somewhere on the extended line that runs from the clew to the luff and meets the luff at a square angle.
    [attachment=2:2zlosoob]Genoa.jpg[/attachment:2zlosoob]When a Genoa is furled (the white area), the fairlead position doesn’t change. In real life we do move the fairlead but that is because we want to adjust our sail shape, it is not caused by furling the Genoa.

    Here is the same sketch but it now depicts a Genoa (Grey) and a Jib (white).
    [attachment=0:2zlosoob]Jib.jpg[/attachment:2zlosoob]When we apply the same rule (the fairlead is on the extended line from the clew to where it meets the luff at a square angle) it is clear to see that the line meets the deck much further forward compared to the Genoa sheet. This is why you need an extra set of fairleads for a jib or a storm jib (dotted).

    If you use one of those storm jibs that is cut high above deck (to drain water quickly and to avoid it being led to the cockpit) the clew may be on the same line as the Genoa’s. If that is the case you don’t need the extra fairleads on the breakwater for your storm jib, you may just as well use the Genoa fairleads.
    [attachment=1:2zlosoob]StormJib.jpg[/attachment:2zlosoob]
    It is all about geometry.

    Instead of extra fairleads a barberhauler can be used or one can be jury rigged with some rope with a bowline around the sheet. Maybe you should have a look at how some of us use a barberhauler on the Spinnaker sheets. I see no reason why a similar solution shouldn’t be used on Genoa/Jib sheets.
    On the other hand, having separate fairleads allows the use of a separate jib sheet avoiding the need to move it from one sail to another.

    hope this helps.

    #10805
    Fundoctor
    Member

    Thanks to you both for considered replies. I noted that jib was cut very high off the deck and to my untutored eye was setting well. I need to fly it again and take another look. Is there a good way of checking if the sheeting angle is correct? I guess moving the jib cleat slider forward would be a good idea in any case?

    Kind regards

    Trevor

    #10806
    Swiebertje
    Participant

    Fairlead forward: More pull on the leech, less pull on the foot –> fuller sail
    Fairlead aft: Less pull on the leech, more pull on the foot –> flatter sail.
    Even further aft –> Little or no pull on the leech causing the top to open and spill wind.

    The geometry I showed earlier is only good enough to find a starting point, but the best fairlead position is found while sailing and watching how the sail and the boat behave. The fairlead position is adjusted again and again, depending on wind wand wave conditions of the day. Mike macNamara wrote some very good essays about it, they are on the UKWA web site somewhere.

    Maybe you should put the sails flat on the a floor some day and check the geometry and sheet angle with a plank? It should give you some idea how the sheeting of the storm jib compares to your other sails.

    Please note that no exact answer can be given as sails may differ in shape, depending on their age and sail maker (ideas about the perfect sail shape have changed over time). The “magic numbers” you find on the web site and with several sail makers are valid only for brand new racing Genoa’s. And even those require an adjustable fairlead.

    Sailing is not an exact science. Go out and experiment. Keep a log so you can compare the effects of your trim settings. Sew one or several thin yarns through the sheets as a reference so you can log and compare your sheeting. I have used self adhesive rulers on the boom and next to my muscle box. Make notes about:
    – Sheeting
    – fairlead position
    – Sail used
    – Kicker tension
    – Outhaul tension
    – Basic rig tension (without kicker and outhaul).
    – Mast rake
    – Spreader length and angle
    – Where did the crew sit?
    – Was the crew hiking out all the way?
    – etc. etc.
    – And moist important: Note your feelings: Did it feel faster beating/running? Was it more stable? Were you in control?

    It is a lot of work but it is a good educational experience. And never be afraid to try something new. Sticking to the old never made a winner.

    But the best: Have a chat with your fellow sailors in your club and ask them what they do, and look at their boats. I have not met a Wayfarer sailor yet that has secrets about their set-up, Au contrare, every sailor loves to talk about his boat and his set-up. 😉 Give him a beer and get ready for an afternoon full of free information….

    #10807

    I carry a small job as well as a genoa, and often find myself swapping sails whilst underway.
    As I sail a World, the spinny chute comes in handy for quickly stuffing the spare sail down under the deck.
    I have fairleads fitted on the aft end of the foredeck that I use when flying the jib- otherwise the foot flaps like crazy. As Sweidbert says, it will depend on the cut of your jib!

    My usual tactic for a sail change is to, ideally, have anticipated the need to do so and have the other sail already clipped on at the bow. Then get your crew to swap the windward (slack) sheet onto the spare sail. Put in a tack, and drop the working sail from a hove-to position. This helps stop it falling into the water. Tidy it up, swap the remaining sheet and the halyard, and then let the sheets go as you haul it up.
    I use a muscle box and don’t normally have any problems getting the hook on, although I can struggle to get really good tension on the luff if the main is flying, but there’s not much you can do about that.

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