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Flat cut # sides sails [bolger] Sharpie sprit-boom leg-o'-mutton sail twist control

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  • Chief Redelk
    I fully agree with a 4 sided sail I got a LOT better results with them cut to shape and darts...BUT,,in high winds I had one that would NOT point.. It got me
    Message 1 of 1 , Jan 7, 2014
      I fully agree with a 4 sided sail I got a LOT better results with them
      cut to shape and darts...BUT,,in high winds I had one that would NOT
      point.. It got me into trouble. I believe it had to much camber.. I
      cut a flat 4 sided sail and it was not good either.. BUT the 3 sides
      sail I am using now is working great. However I must sail it much
      differently than a sail with camber.. My flat cut 3 sides sail loves a
      LOT of camber and I just let slack out on the spirit boom and the sail
      billows out..

      As far as pulling the sail in line with the middle of the boat that
      was the ONLY way I could get it to point really close to the wind. I
      do not do that with a professionally build 3 sides sail..BUT my flat
      cut sail will out sail my professionally made sail with camber build
      into it.. I am not sure why..

      I did have to learn HOW to make my flat cut sail work but I love it
      and it's working well..

      Later I may find I can improve on it by adding a dart... I am still
      experimenting at this time and loving the sail as it is..

      Making this boat sail was much different than a PDR or my skiff but I
      think all boats may sail differently..

      I am happy with the flat sail and have made one for my Skiff and will
      give that a try when I get time..

      I would say, don't be afraid to try a flat 3 sided sail.. I do not
      believe a flat 4 sides sail is worth my time. In fact there was a time
      Sprit sails were my favorite. Those days are behind me now as I move
      into 3 sides sails. Flat cut for now, maybe cut some roundness into
      one later and see how it works.. Good night, Chief....

      On 1/5/14, mason smith <masonsmith@...> wrote:
      > Anent this subject of flat vs shaped sails I have had some interesting
      > experiences. First with respect to lug sails. According to my
      > understanding,
      > the wisdom around WoodenBoat was that lug sails, as for the Nutshell Pram,
      > should be flat, and, according to my understanding, Robin Lincoln made them
      > flat for the Nutshells. When I rigged my earliest Goodboats for sailing, I
      > had Robin make standing lugsails for me. They were, I believe, utterly
      > flat.
      > When I needed sails sooner than Robin could supply them, I got some from
      > Douglas Fowler, who put about 8 inches of draft in my approximately 72 sq.
      > ft. sails. In identical boats and crews, they literally sailed circles
      > around the flat sails.
      > In sailing my Micro, with sprit-boomed leg-o'mutton sails, as in sailing my
      > Goodboats with their standing lugs, I find that lots of draft is usually
      > good, even in surprisingly strong winds, so I set the snotter just hard
      > enough to keep the luff full. These sails reshape the wind even in their
      > lower parts, so that they themselves alter the apparent wind greatly, at
      > the
      > luff. There's more forward vector in the resultant force and less heeling
      > moment. As for sheeting, I have never found a set of conditions where the
      > Micro likes to be sheeted anywhere near the centerline.
      > PCB has pointed out how much the cut of the sails affects the performance
      > of
      > 4-sided sails. How do you tell? I have wondered whether the Whalewatcher I
      > built for Pat Connor had the benefit of really well-cut sails. They are
      > pretty, and that boat sails very well, but how well cut are the sails, and
      > how well could it sail? There's only the one example.
      > I have some experience in sailing the decked sailing canoes of the late
      > 19th
      > century, especially Rushton Vespers. In them, the various spars of the
      > antique bat-wing or "modified Bailey rig" are stiff. They are apparently
      > intended to make the sails as flat as possible. Those old boats do sail,
      > and
      > are great fun to sail, but it would be charming to see what they would do
      > with airfoils in place of inclined planes for sails.
      > Can't resist a comment on boomless loose-footed sails. I have had two
      > Drascombe Luggers, which sport this kind of sails in gunther yawls and have
      > a great reputation. On both of them I was so annoyed by bad, baggy sail
      > shape off the wind that I rigged sprit-booms, for safety and performance.
      > Spritbooms are not really convenient on gunthers but I rigged them and they
      > were worth the inconvenience. On the second one, I laminated a curved
      > sprit-boom that I called a half-wishbone. Instead of a snotter it was
      > fastened to the mast with a little connector and a vestige of the other
      > half
      > of the wishbone, if you can picture that. This juncture wrapped around the
      > front of the mast and was held by a lashing that went around the after side
      > of the mast, as on a windsurfer. The draft was controlled by an outhaul
      > near
      > the clew, easily reached at the helm. So rigged, with decent sail shape on
      > reaches and runs, my Lugger easily beat the fleet at the North American
      > Drascombe meet and in match races against all comers including the much
      > longer Longboats. I was given the trophy somewhat reluctantly.
      > That don't prove anything about the flat vs cut sails argument but I would
      > say that the shape a flat sail takes up when the snotter is loose is
      > nowhere
      > near optimal. It'll sail, agreed, but it will not yield the "supplementary
      > clean gain" that a well-cut sail will. I don't consider good sail shape a
      > luxury on a sailboat, and even if I made my own sails out of Tyvek, I'd
      > build shape into them, and rather more than less, for the kinds of slowish,
      > smallish boats I sail.
      > From: bolger@yahoogroups.com [mailto:bolger@yahoogroups.com] On Behalf Of
      > Chief Redelk It'll Sent: Saturday, January 04, 2014 2:33 AM
      > To: bolger@yahoogroups.com
      > Subject: Re: [bolger] Sharpie sprit-boom leg-o'-mutton sail twist control
      > I've recently experimented with a FLAT cut Leg Of Mutton Sprit boomed
      > Sail..This was my FIRST flat cut sail but I had read that someone was
      > doing it so I wanted to give it a try...
      > This is what I learned...First,, the wind was about 10 to 15 miles per
      > hour and my snotter is adjustable from the cockpit.. I always do that
      > no matter on all my boats. So I was confident with the adjustment.
      > The boat sailed crappy and would not point well at all. In fact I was
      > being blown lee so I tossed out an anchor and played with the rigging.
      > First. I thought it was the lee Board so I swung it back and forth but
      > no sail would not p
      > From my experience in Sprit Sails with darts I felt the camber was
      > right if not on the TO much side so I tightened the sail some then
      > some more and finally flat. NOPE. Did not work..
      > Finally I decided to let TO MUCH sail out and see what happens. The
      > sail began to pull..
      > I was off the wind and zooming along at a nice heel. The boat was
      > surprisingly active and fun.
      > Then I went down wind right up into a cove came about into a head wind
      > and began to tack out.
      > On each tack the boat moved well giving me the illusion I was tacking
      > back into the open waters BUT I realized I was NOT making good head
      > way. In fact I kept arriving almost at the exact spot on the shore
      > line with each tack so I realized something was amiss and I tossed out
      > the anchor again and started playing with the rigging..
      > Lee Board swung aft did not work so I swung it forward yet nothing was
      > working..
      > Then I remembered how I had to let out TO MUCH slack on the snotter to
      > get it moving so I said, WHY NOT try that..
      > Then I let out a LOT more camber than I would normally consider and
      > pulled the sheet in line with the center line of the boat and that did
      > the trick..
      > She pointed close to the wind and when I once again hit the open lake
      > she heeled over steeply and sailed like a dream. In fact I was moving
      > faster now with all that big camber than before..
      > Here, all this time I had always had to TIGHTEN my sprit sail to point
      > into a stiff wind but now with the flat cut sail I was sailing
      > windward with a VERY Loose Snotter....
      > The trick to point into the wind on this flat cut LOM seems to be to
      > have a LOOSE sail creating lots of camber and the boom sheeted near
      > the center line..
      > I was on the far side of the lake when the wind dropped late in the
      > evening like it does most of the time on this lake.. I moved forward
      > so the boat sit on the rocker and sailed her flat. The sail was
      > cleated off and the rudder tied off. The boat moved slowly along but
      > very predictable. Then I made a turn for the landing with a light tail
      > wind.. The boat seemed to be bogged down and it was getting late in
      > the evening so I sat on the same side as the sail heeling the boat as
      > far over as was safe.. The light tail wind filled that big ole loose
      > sail and we moved nicely along reaching the distant shore long before
      > the sun disappeared..
      > What I liked about the Flat Cut sail is it's FAST and EASY to make.
      > Sailing it was DIFFERENT but once I caught on it worked great..
      > I am not sure IF I will continue to use Flat triangle sails or not but
      > I did learn they can be made to work if you fly the snotter as loose
      > as you can given the wind conditions..
      > Good night, Chief..
      > On 1/4/14, c.ruzer@... <c.ruzer@...> wrote:
      >> How about those traditional sharpie "simple but sophisticated
      >> sprit-boomed
      >> leg-o'-mutton rigs"? I knew the trick to adjust draft in the sail, make
      >> it
      >> fuller in light wind for more power or flatten it when the wind gets up
      >> to
      >> de-power it by working the snotter on the sprit-boom. I've read about
      >> that
      >> just about evrywhere these sails are written of too. The benefits from
      > being
      >> a self-vanging sail, done so simply, and eliminating twist without the
      >> bother of a mult-part kicker on the boom is often mentioned too.
      >> But of course there's going to be a little bit of give and stretch here
      > and
      >> there in the rig, and the usual prescription is to tension the snotter as
      >> necessary to minimise the twist - but there's always still going to be
      > some
      >> give - and you might be flattening the sail more than you want for best
      >> performance. So what to do? Well it's so easy and elegant, and if I've
      > read
      >> or heard of it I've never taken it in before:
      >> "If we rig the snotter so that its height on the mast can be changed
      >> while
      >> underway, sail twist can be adjusted (ie. dialed in or dialed out). This
      >> simple adjustment can increase speed and dampen rhythmic downwind
      > rolling."
      >> Your expensively cut modern bermudan mainsail and rig uses all those
      >> dollars and complicated highly tensioned mechanisms to adjust twist, but
      >> for the sharpie just use any simple way to alter the height of the
      >> snotter
      >> on the mast. Brilliant! I look forward to trying it.
      >> Twist, the right amount at the right time is good. The windspeed and
      >> underway the apparent wind angle too increase significantly with height
      >> above water. A sail that's twisted right with the head falling off just
      >> so
      >> presents an appropriately changing angle of attack to the changing wind
      >> angle and develops more power, is more efficient. When running minimise
      > the
      >> twist to minimise oscilating vortices, no death rolls, and efficient.
      >> Is this trick of altering the snotter height mentioned in 103 Small Boat
      >> Rigs? That's a book I'm putting off getting - some say the best one (save
      >> the best till last;). I've not seen PCB or Chapelle write about this. In
      > one
      >> of his books Dynamite comments on the low angle of a sprit-boom as drawn
      >> saying it would be better at tensioning the foot if it bisected the clew
      >> angle. He was thinking only of how much more he could flatten the sail
      > with
      >> less effort applied to tensioning the snotter and said he'd mention it to
      >> PCB. I think all those 59sqft LOM sails afterward are shown with more of
      > the
      >> sprit-boom angle Dynamite was after.
      >> Anyway there's a few more good sharpie sail tips here:
      > http://groups.yahoo.com/neo/groups/bolger/files/Shoal%20Draft%20Sharpies%2C%
      > 20and%20Bolger%20on%20lugsail%20peak%20halyards/
      > http://groups.yahoo.com/neo/groups/bolger/files/Shoal%20Draft%20Sharpies%2C%
      > 20and%20Bolger%20on%20lugsail%20peak%20halyards/
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