The Merits of Flat-Cut Junk Rig Sails by Kurt Jon Ulmer
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The Merits of Flat-Cut Junk Rig Sails by Kurt Jon Ulmer Cambered sails are better than flat ones. An iPad is better than a Linux netbook. A diesel auxiliary, better than an electric motor. But I’m writing this on an old Linux computer, in the pilothouse of a flat-sail junk rig yacht with electric propulsion. Why, when I could have... all the best? Converting mehitabel to Junk Rig ‘Practical Junk Rig’ and my own brief study and common sense were all the resources I needed to create the junk schooner rig for mehitabel 10 years ago. We still use our first set of junk sails, and they’re lasting well. First set of battens too, with the original scantlings. Our top batten just below the yard is now doubled, as a preventative. The only-ever bend was minor, caused by my over-sheeting while hove-to for several days. Same yards, but I had to lengthen them because I ignored Hasler & Kurt Jon Ulmer McLeod on that detail initially. I cheated Hasler & McLeod for the sake of sail area on a Sail planform of mehitabel. Now that’s flat... couple of other points, and each has shown up as a mistake we live with. New booms, a gift from Paul Thompson. New fendering, since leather is abrasive and polythene is better. I’ve made few other changes, and never had any breakages nor the urgent necessity to repair anything at all. (How far? How hard? How long? Approaching 6,000 junk sea miles, after about 10,000 under Bermudan cat schooner rig. Gales, yes. Lived aboard 17 years. In constant refit of something or other, but not the rig.) By the time I was planning mehitabel’s rig, Arne Kverneland had shared the details of his cambered panel sails, and other inventors had documented a few bend-and-stop batten devices. Why didn’t I go for a then-state-of- the-art junk rig with some form of added camber? I resisted the temptation because: Boats had sailed Well Enough on all the open oceans with flat-cut sails; I had no mentor for making the cambered panel rig offshore-reliable, while I had Hasler & McLeod for the flat-cut option; I could easily have gotten it wrong and then needed to re-sew the sails to put it right; The camber seemed so compromised by Kurt Jon Ulmer distortion at lifts and mast, that I wondered, “But is this flat?” ‘Why bother?’; I wanted no flogging, flapping or fluttering problems; I had learned that strains were distributed in junk rigs, and I thought loosening up the fabric would result in point loading; I had only a few months before an offshore trip; Finally, I could foresee expenses, complexity and time going beyond what we were ready to commit. Also, I saw a way to add camber in the future, by retrofitting and perfecting bend- and-stop battens. This gave any over- ambition an easy way out. The change later on wouldn’t require new sails, wouldn’t point-load the spars so, wouldn’t lead to flogging. The battens could be phased in and taken out experimentally. ‘Bend-and-Stop’ sketches led me to ‘Smooth-Curve-and-Stop’ ideas - an intriguing design problem for idle hours, but I put off any extra work until I reckoned we needed added camber. Later. It is later. The sails are still flat. Flat-cut, that is. David Tyler Twisty full sails, close-reaching in very light air, with camber enough Cambered Panels Now and battens, breaking of battens, things by pulling harder than sails banging when rolling in a before on certain points, ignores In 2012 there are excellent seaway, qualms about motor- the fact that it’s the distribution of resources to get one started sailing behaviour, and batten ends strains in the junk rig that makes it cambering. With study and fouling sheetlets because of innately robust even with weaker common sense there’s no reason negative stagger when reefing and individual parts. someone can’t make good-as-can- furling. They’d be called serious be cambered sails today. The Fays Putting skinny slick tyres onto a on mehitabel, that is. None of them did, for Ti Gitu; Anthony mountain bike gives instant happen. Swanston, for Wild Fox; Annie Hill results. It goes faster, rolls for Fantail; Graham Cox for Arion; They are products of departing smoother, steers easier. You David Thatcher for Footprints; from the tried and true, which wouldn’t like it in winter in David Tyler for Tystie. always invites difficulty - now Canada. Risky on jumps. And it we’ve defined the word adventure still won’t win a road race. There are many others, of course, pretty closely. and also several methods besides To some people, a mountain bike is adding camber to each panel. Less The problems of cambered sails a whole concept, an organism discussion is heard these days will be solved. That’s what almost. Evolved to be something, about hinged battens, pre-formed humans do. In the process of with its own integrity; best if curved battens, wingsails of perfecting their rigs, JRA members uncompromised. If a mountain various kinds, etcetera. But we can are lucky. They get the benefit of bike isn’t Good Enough at be sure there is still considerable each others’ sea trials in real time, something important, well, there ‘messing around,’ some of it with and from all the oceans at once. are other bikes. success. This is a very cool and useful My primary aims for this long bold Association. Some of the people mentioned article are to argue for the above, have had serious problems. But to react with heavier scantlings functional integrity of the basic They include frustrations with sail as solutions, is to use brute force ancient junk rig, and to elevate the setting, severe bending of yards instead of natural toughness. To fix strange idea of Good Enough. Topical Thoughts Genoas and Dipping Lugsails Gorgeous camber, a fine clean leading edge, smooth tailored curves undamaged by the press of mast or lifts - why aren’t we talking about these? We can discount dipping lugs because wonderful as they are, they don’t make for an easy, general-purpose rig. Although some of us would enjoy the lift genoas can provide, sometimes, and some of us would like to win races against them, they offer nothing to compare with the handling advantages and versatility, and the inherent robustity, of the well-sorted junk sail. Theresa Ulmer Junk sails have one huge advantage Reefed fans - more effective than they ought to be over genoas. No, two. They can Nothing happens. Motor-sailing, of lifts and mast, it suffers present a large area of sail, high up rolling in a sloppy sea, anytime the deformations. Excuses can be made and pulling, when a genoa will flop sheets are let go, nothing. that the air skips over the dents pitifully. And they don’t need such and bumps, deceived, and nothing More power from cambered sails strong corners. But there’s more. is lost, but I don’t buy it. Smooth is induces more heeling, all else being Self-tacking, reefing without going smooth, or glider pilots wouldn’t equal. Not only more heeling, but all baggy, sheeting without wax their wings. more changes in heel angle with winches... changes in the wind, self-steering We can hardly praise the junk rig Camber Itself corrections, speeding and slowing for having no standing rigging and over swells, etcetera. On a sport- praise the kind of junk camber I see Imagine that we hang two sailing day nobody minds a little in many photos, in the same breath. bedsheets on a line some breezy excitement. On passage I don’t After all that careful broad-seaming day, one a fitted sheet and one welcome it particularly. There or shelf-shaping, don’t you just plain. Pin the plain one with 8 pins might be a cake in the oven. want to let the lifts go slack? Ah, evenly spaced along the but this is a junk rig, so it’s not clothesline, and the fitted one with It makes sense to position the sheet usually done. It would be more 1 pin, or 4 pins if you like, only at over to windward when hard on work. each of two corners. No, that’s not the wind with cambered sails, in fair. Cambered panels are attached order to make best use of the Yards and Battens to their battens much the same as different, improved entry angle at It's a tough life! Yards press and flat ones. It’s from then on that they the sail’s luff. Athwartships horses then bang against the mast and the behave differently. You may use 8 or other inventions are useful if lifts, and get gusted around pins, then, spread along the edge. you sail that way a lot. A big hook unpredictably, gybe roughly But be ready to catch them. Which on a purchase to the weather rail sometimes, and may even get sheet will unpin itself or tear itself, might be the Chinese answer, and a pulled hard and unfairly against a in a gusty afternoon sea breeze? crew member to manage it. forgotten sail tie. Occasionally. I’m All analogies limp, but I’ll venture Flat-cut sails are more tolerant of getting better. Battens suffer from one more point from that one. The sheeting angle when sailing to sheeting forces that are inevitably plain sheet can feather itself with windward, and don’t need an too-much-downward, from the wind, while the fitted one has answer.