Kurt Jon Ulmer wrote:
Slieve McGalliard wrote:
I still don't understand why home builders and sailmakers have continued to build flat sails after you demonstrated such a simple way to get good bangs per buck.
Hello to all,
It's clear why people look to improve the sails recommended in Practical Junk Rig. There are a few things, (well, actually one thing) they don't 'perform' superbly at.
I constantly admire inventiveness. The WingSails, Fantails, Split Rig, Cambered Panels, AeroJunk, etc... are impressive even without controlled trials. I think I made a couple of good tweaks myself. Good on me! (ahem...)
But Slieve, there are reasons. Not intensely exciting, as in 'bangs per buck.' Still, I wrote about mine in JRA Newsletter 61, titled 'The Merits of Flat-Cut Junk Rig Sails.' It's also in the Technical Articles section, possibly out of place somewhat, but a great honour nonetheless. Surprised me. It doesn't even try to solve the 'one thing' mentioned above.
I used the phrase 'Good Enough' in favour of robustness and simplicity. Little reponse to the ideas on my little flat grey placard (well, one 'Flat-Earther' joke...) Actually, maybe a couple of new sails were made flat. I don't know.
Anyway, 'Hey Richard, Here's what you do...' (only kidding)
Cheers, Kurt
Hey Kurt,
Just for the record, my first junk sail was a cambered sail made from Odyssey 111. When it fell apart after 4 years, I was inspired by your example to build a flat-cut sail, though it too turned out to be flattish, rather than "barn-door flat". I have three fanned panels and put 20mm of rounding along the battens in those panels. The four lower panels are parallel, in classic HM style, and are cut flat, but they have deep hollows in the leach, which tends to flatten out the aft end of each panel, while the straight luff allows some scalloping in the forward part of each panel. Thus the panels end up with a tiny amount of camber. Also I have a short yard which allows the top batten (unsheeted) to fall off a little, adding camber to the top panels, which in my opinion are the powerhouse of a sail to windward. I am delighted with the light air performance of this sail in smooth water. In a chop, my fat hull was always somewhat sedate. One thing I have noticed is that the boat is slower to accelerate out of each tack than it was with the cambered sail, so a short-tacking duel would put me at a disadvantage. Nonetheless, I love the robust simplicity of my sail, the way it stacks perfectly even at 0300hrs on a dark, squally night. It really is a "fully automatic" sail, to quote Blondie Hasler.
I am a bit impatient with those who sneer at flat-cut sails without qualifying their argument. I understand that if you mostly sail around enclosed waters, or race, you might become obsessed with windward performance, but the sort of cruising that interests me entails avoiding windward work mostly. Also, flat-cut sails are very simple and robust, and I consider it beyond doubt that they spread the loads more evenly throughout the sail. For offshore cruising, these qualities mean more than windward efficiency. Anyway, one of the joys of cruising, for me, is to abandon time constraints. Once I stop wondering when I am going to get there, I slip into a delightful harmony with life, colours become more vibrant, all my senses come alive. I am currently researching an article about Kris Larsen on Kehaar. Kris has sailed more than 70,000 miles in the last 30 years with flat-cut sails made from all sorts of throw-away materials, without an engine, and demonstrates beyond doubt that the concept of "good enough" works very well for voyaging yachts with junk sails.
PS: I might add that cruising without a primary focus on windward performance need not be limited to ocean voyaging. My most delightful sailing really is just mooching around in sheltered waters, not caring how long it takes to get somewhere, knowing I can just drop the anchor whenever I feel like it in a nearby anchorage. I'm also interested in the work of those developing cambered junk rigs and watch their work closely. My only criticism is that cambered rigs, for all their potential advantages, do not render flat-cut junk sails obsolete.