Transition sails from Richard Dryden

Discussion in 'Sailboats' started by Pericles, Mar 13, 2008.

  1. Pericles
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    Pericles Senior Member

  2. CT 249
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    CT 249 Senior Member

    I've looked at it several times over the years, and still never seen any advantage to the rig.

    Yes, it can be folded away, but so can a conventional gaff or gunter. It claims that in a yacht you could possibly fold the whole rig below when not sailing - but how complex would that be and why would you bother?

    The compression loads and engineering and weight problems in the joints worry me, when compared to the other way of flattening a sail - mast bend. And he admits that there is no cloth that will work like the animal wings he uses as inspiration.

    The planform for most of the rigs seems to be totally against all theory and practise. And rigs already work elastically and already respond to the breeze.

    I find this a common thought; "believe that this direct contact with sail forces, together with the relatively small size which encourages experimentation, is why the pace of rig development in windsurfing has been so rapid compared with sail development in other branches of sailing."

    But is it true? The modern windsurfer sail, with its full battens that load against the mast, the pocket luff, the roach, and the twist, is very similar in concept to the Moth rigs of the 1960s. And a modern windsurfer rig has its own performance problems and restrictions. Sure, what they do well they do very well, but what they do badly they do very badly. They're different from boat rigs but whether they are better is another question entirely.
     
  3. Hansen Aerosprt
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    Hansen Aerosprt Junior Member

    Just curious, what do they do badly? What restrictions do you see?

    CT249 wrote:
    <<And a modern windsurfer rig has its own performance problems and restrictions. Sure, what they do well they do very well, but what they do badly they do very badly.>>
     
  4. CT 249
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    CT 249 Senior Member

    Area for area, weight for weight, they seem to create significantly less lift/power in light winds than a sail with more draft and a tighter upper leach. I've actually had this confirmed by a performance prediction guru who tested a bunch of modern rigs for a major builder and then threw in an old rig as a comparison and was shocked by the result. It's also been confirmed numerous times sailing when we race longboards. The UK Raceboard scene is dominated by a tighter-leach higher-aspect design for this reason.

    Personally, I think the fact that the modern sails stress low drag for top-end speed so much really has an effect on sailing, because we end up chasing strong winds too much despite the fact that wider boards allow us better light wind speed. Sigh.

    Sure, you can then use a bigger sail as guys like Barry Spanier say, but that's a problem in itself because the whole damn thing gets to be so heavy when manoeuvring or uphauling. Handling on is one thing in a nice steady breeze in open water, it's another in a typical light and shifty location in 4-9 knots. And as one of the nation's top FW sailors says, "its a slow and brutal process on an 11.8m compared to uphauling a 6.2m." Good, strong sailors find an 11.8m brutal, sailors who are weaker in skill find even an 8.5 to be difficult, especially when the luff pocket fills up.

    IMHO an "old style" more powerful tight-leached sail of smaller area is a lot easier to handle in confined waters and gusty winds in some ways - get a sudden knock and it's less likely to backwind and easier to trim to the new direction.

    I sail the '80s update of the original Windsurfer more than anything else these days, and I'm interested in the way it performs at extremes - when it really blows hard we can allow the sail to backwind and survive in conditions where raceboard sails invert. In light and fluky winds, the lighter and softer sail is easier to handle and faster to react. Sure, the modern sails are vastly faster in medium to strong winds in terms of top-end speed.

    Because the modern rig is designed to sail with aft rake and the foot gap closed, you cannot move the CLR much further back when you want to tack. Therefore tacking becomes much less slower and you lose a lot of the tactical avenues. And in light winds I find having to hold the sail in a raked position to be quite cumbersome and annoying.

    It seems to me that many of these problems (like the difficulty of uphauling a large but flat sail with a large luff pocket) open up the gap between people of different skill levels and strength; one example perhaps being the tiny number of women who race boards these days. Sure, they work for the world cup guys, but most people aren't WC sailors (I used to race against the top guys in earlier years, I know how differently they sail to Joe Average).

    Monofilm's durability can be a problem, and rigging a fully battened cambered sail is normally much harder than rigging a simpler sail. And of course, battens and cambers and extra area all equal extra $$$$, complication and weight.

    On dinghies, the rigid fully-battened sails can be hard to handle ashore in conditions British sailors sail in. They often have long and narrow ramps down to the water, and the fact that the rigid sails have no "neutral" makes life hard - RS have gone away from rigid sails to a floppier type.

    Dinghy/skiff rigs that have to be rigged laying down can be a disaster in some ways. When the 12 Foot Skiffs moved to rigs that had to be set up with the boat capsized, they lost half their fleets - because half the clubs didn't have enough room for boats to be on their side.

    Similarly, lots of our clubs have very crowded rigging areas. If we have to rig our boats on our side, there would be major problems.

    One of my classes has gone to film sails and some of the best are very disappointed with their durability. I still have a club-racing mainsail from about 1980; the new sails are lasting about 2 seasons. For club racing, the old dacron sails can be great.

    I like modern rigs, I own a bunch of them (from my carbon Canoe mast, to slalom gear, to the wing masts on our F16 cat and Tasar) but i have to admit I'm intrigued by the way sails that are as simple as a Laser or Windsurfer OD rig can also perform very well and be very practical and easy to operate. It's not just a case of "modern sails good, old sails bad" as sometimes put.
     
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  5. Hansen Aerosprt
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    Hansen Aerosprt Junior Member

    CT:
    You points are well-made.

    Seems your prime criteria is lift/power-per-unit area in light winds rather than use-able wind range. In this case, Formula racing rigs being highly specialized have indeed become extreme. But, we've managed to reclaim much of the low-end with the 'compliant leech' which allows a fuller, tighter-leeched sail to progressively flatten and twist off automatically under load in gusts, etc. This technology is equally applicable to the more generalized sails you describe. I don't agree that categorically, boardsails suffer as severely as you say. There are plenty of lightweight, powerful and stable sails available. They would not win a Formula race but they would do well on a longboard in light wind.

    <<Area for area, weight for weight, they seem to create significantly less lift/power in light winds than a sail with more draft and a tighter upper leach.>>
     

  6. CT 249
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    CT 249 Senior Member

    Thanks, Bill.

    By "modern windsurfgs" I was meaning FW, slalom, etc rigs. I actually like sails with a wide useable wind range, but it does seem to me that many windsurfer sails do rather tend to ignore the bottom end of the wind range, as well as simplicity, swing weight, etc.

    I may have over-stated the case, but that's partly a reaction to the fact that I often feel the case for modern rigs is over-stated in some ways. These days I'm more concerned about accessibility, simplicity in the light winds most places normally get, etc and the way that some people promote "modern" rigs (which aren't very different in some ways to the ones that were old when I had my first Moth) seems to ignore the benefits of other rigs. The Byte CII seems to be a case where (as I understand it, and I may be wrong as I;ve only sailed one once and looked at yardsticks) the supposed huge superiority of the modern rig just isn't borne out in reality. I think it's more of a "horses for courses" deal than simple superiority either way.


    The complaint leach looks cool, as do all your sails
     
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