Balanced Lug Sails

[T. Traddles]

I'm thinking about adopting one for my present boat. Does anyone know what percentage of the sail area falls fwd of the mast? Thanks.

[StevenBauer]

Wouldn't it depend on the balance of the boat in question? Play around with it until it feels right. That's one of the beauties of the rig. In different conditions you can make small adjustments to where you tie the halyard to the yard and where you attach the boom to the mast.
Or just wait until Todd chimes in with the real answer. :D

Steven

[keyhavenpotterer]

This picture of my Lymington River Scow gives you some idea of the proportion forward of the mast. The downhaul is positioned about 10" back from the front of the boom.

http://farm4.static.flickr.com/3230/2821243592_a13a748979.jpg

Look to have the luff in line with the mast. Michael Storer uses a halyard attachment from the 1890's. Fix halyard at front of yard, round the mast to a block at 50% of yard length, then up to the mast sheeve. This sets the sail well but also keeps it setting well when a reef is put in. Our Scows set the halyard at about 40% along the yard, but the halyard attachment has to be moved when reefing.

You will find you can adjust the amount forward of the mast depending in what order you apply the controls. Kicker first will pull it forward, downhaul first ( if you fasten the downhaul at the front of the boom) will pull it back so it's only just in front of the mast.

Mainsheet tension may pull it forward or aft depending on take off position.

As I let off downhaul and kicker racing off the wind, the boom will come across the mast more and make it even more balanced downwind, avoiding using the helm as much as possible. Then stear by healing the boat, helm in the middle and bob's your uncle, your flying downwind.

Sure Todd will be along soon.

Brian

[Ian McColgin]

Gary Hoyte has an innovative variation on the balaced lug with a good third of the sail area ahead of the mast. Some other interesting winkles as well.

[T. Traddles]

Brian, I love the looks of the scow!

Paul Gartside has an arrangement on his balanced lugsails whereby a boom jaw is attached to the boom and rotates around the mast. This keeps the boom off of the mast, but it would seem to render any adjustment to the sail impossible (e.g., those mentioned by Brian in his post). Any advantage to such an arrangement?

[Songololo]

Some good info on Michel Storer's home page regarding the lug rig. Here is the GIS's sail plan:

http://www.storerboatplans.com/GIS/gissailplandwg.jpg
See his FAQ page here (http://www.storerboatplans.com/Faq/tradrigperformance.html)for more details.

[john welsford]

On a performance boat I might use as little as 7 or 8 % which puts more tension on the luff, but on a dayboat where the boat might be sailed lazy and gybes without thinking will happen, I'll go up to maybe 15%. The difference being the more area you have ahead of the mast the more gentle the gybe, the lighter the sheet tension and the easier the sail is to manage.

This rig is very tuneable, easy to rig, gentle to manage, more efficient than most think and well suited to knockabout sailing.

John Welsford

I'm thinking about adopting one for my present boat. Does anyone know what percentage of the sail area falls fwd of the mast? Thanks.

[Woxbox]

I've got one on my Whisp, and for me it was a matter of trying different things until the sail set properly. My boom is light and springy, so I couldn't get good luff tension without placing the downhaul well forward. The halyard is maybe 25% up the yard. So the luff is not parallel to the mast, but it does work fine, and reefs well, too. Keep in mind the position of the sail affects the balance of the boat too. It's a very flexible rig, and it pays to tinker with it.

If you get creases or wrinkles across the sail, of course you're way off and the first job is to get the canvas to set cleanly. You can figure that part out before the boat goes into the water. After that, trial and error will get you there.

[Todd Bradshaw]

You guys are doing just fine. Obviously, there is always the caution when changing rigs that winding up with the Center of Effort for your new rig in a substantially different location or altitude from the original plan's CE can cause trouble, but for balanced lugs, as noted, there are a lot of variations possible (and in use) in terms of the amount of mast overlap present.

There are, however, a few specific and inter-related things that need to happen in order for the lugsail to work properly. To start with, all balanced lugs have booms. The angle of their luffs are generally parallel to the angle of their masts (or pretty close to parallel though I'm not sure this is particularly critical). Masts may be plumb or raked, with luffs to match. Since the luff edge is flying out in space, ahead of the mast and not attached to a spar to keep it straight, we have to rely on tension generated by the forward end of the yard pulling up on the luff and the forward end of the boom pulling down on the luff to keep the luff tight and prevent it from flapping or wandering from side to side.

Here are a couple of balanced lugsails.

http://webpages.charter.net/tbradshaw/!SOLOBOP.jpg

We tie the halyard to the yard at a spot forward of the yard's center point (it can vary, but I usually shoot for a spot 40%-45% of the yard's length aft of its forward, heel end). We want the yard to be "tail heavy" and pivoting on the halyard tie-off point (generating force "A" in the drawing) this helps force the forward end of the yard upward (labeled "C", which is one of the forces we need for generating good luff tension, as mentioned above). The weight of the boom at its aft end (and that of the sail itself) also contribute downward force (B). These forces tend to make the entire sail/yard/boom assembly want to rotate, pivoting in profile on the halyard tie-off, dropping the boom's tail to the deck and also forcing the boom forward (D). To counteract this rotation and stabilize the whole assembly, we use some sort of downhaul pulling in the opposite direction (downward and aft on the boom, shown at"E"). In some cases, the "pulling aft" part of this job can also be shared or taken over by a boom jaw bearing against the aft side of the mast. It tends to limit your ability to adjust the rig somewhat, but makes a very solid "rotation stopper". Force E, pulling down and aft against all these other forces which are trying to rotate the whole assembly is what pulls the front of the boom downward and finally generates the luff tension we need (F).

So we have, in profile, manufactured a situation where A,B,C, and D are trying to rotate the sail assembly in one direction, and poor little E has to create enough counter-rotation to stop it and stabilize the attitude of the sail. When we add mainsheet tension on occasions when the sail is sheeted in tightly, it adds even more rotational force in the ABCD direction, and needless to say, the mechanism at E needs to be pretty sturdy.

Two problems that can arise and mess up our plan are (1) locating the halyard tie-off point too far aft on the yard (so that the yard is not tail-heavy enough) and occasionally (2) designing our sail with a peak angle which is too steep (though I know of no specific guideline for just where the limit is because it varies due to other factors involved). These problems tend to reduce our ABCD rotational force too much. As long as mainsheet tension is high, the sail will be stable, but as soon as you ease the sheet to initiate a tack, the yard's heel droops as the yard tries to go vertical and you lose luff tension and sail shape at about the worst time possible. The tail-heavy configuration on the yard needs to be extreme enough that the yard wants to droop at its aft end at all times, not its forward end. This, working against the downhaul makes sure that your lugsail keeps its proper profile with all its spars at the designed angles whether there is wind in the sail or mainsheet tension or not at any particular moment. So whether you have 5% of the sail area out ahead of the mast or 25%, the rotation/counter-rotation issue is at play and can't be ignored. What will work best out on the water for a particular boat is often the product of experimentation while out enjoying your boat. It's a tough job, but somebody has to do it.

[T. Traddles]

Thanks to all who have posted here. I am appreciative of all of your insights. You have given me much food for thought. Gracias Amigos!

[wtarzia]

... The tail-heavy configuration on the yard needs to be extreme enough that the yard wants to droop at its aft end at all times, not its forward end. ...

--- So in such rigs, perhaps there is little point in going for light booms? And in fact, a reasonably heavy boom is useful? (and its weight is low, any way). Sometimes I wonder if I ought to have used solid booms on my standing lugs rather than the light glass 2 inch dia. windsurfer masts that I used to save building time. -- Wade

[Todd Bradshaw]

I don't think a reasonably robust boom will hurt anything (other than adding a little more weight to the whole boat and making a bigger dent in your cranium if you forget to duck) but you might have to go to extremes to make an awful lot of difference in the way the rig sets up. A heavy boom can also somtimes hinder light-air performance, the same way super-thick jib sheets can suck the life out of a jib on those light-air days. I've had a few jibs come in for repair over the years where you just shake your head and chuckle. Here will be some tiny little 4 oz. jib with eight pounds of 5/8" yacht braid attached to the clew ring. It makes you wonder how many knots of wind it takes just to lift the sheets of the deck, let alone fill the jib.

[keyhavenpotterer]

We have had an interesting development recently in our little Scow racing world. The picture I posted above is a Lymington River Scow. Another local variant is the Keyhaven Scow, a grp clinker version. Here I am in KS249, 4 seconds before the gun racing Lymington Scows all around me. Note my black carbon spars!

http://farm4.static.flickr.com/3038/2799141427_3620e6f760.jpg

The Keyhaven version had always been held to be slower than the Lymington version, and was allowed time, racing off .98 against 1.00 for the LRS.

When we produced my boat and similar ones we race now off 1.00 as well.

Then last winter the Rogers family wanted some Scows and borrowed the Keyhaven moulds. This is Jeremy Rogers, of Contessa 32 fame,

http://www.jeremyrogers.co.uk/ and son Simon Rogers top local naval architect. http://www.rogersyachtdesign.com/

They were bound to come up with something interesting for their lug rigged Scows. Their Scows are so quick for a while the Lymington Scows refused to race them. Now resolved by the Rogers boats racing off 1.1. So the Keyhaven Scow has gone from .98, to 1.00 to 1.1 as it is improved.

Sorry setting the scene takes time. And their rig development? They went for a standing lug rigged in a way I have not seen before. The boom is fixed to the mast. So how do they tension the lug yard. They have a free line running up inside the luff of the sail, fixed to the front of the yard.
So the halyard pulls the yard up and tensions the luff, and the downhaul goes straight up to the yard, raised the head and tensions the sail the leach. It gives a very high peaked lug. They claimed very strongly to me the other day that the sail area is the same, but to me the higher peak is giving more area.

With very nice foils and a beautifully cut jib (jig is used for two up sailing), they are going very well and looking great. Ken who makes the Keyhaven Scow is now preparing to make more Rogers variants!

Brian

[wtarzia]

...The boom is fixed to the mast. So how do they tension the lug yard. They have a free line running up inside the luff of the sail, fixed to the front of the yard.
So the halyard pulls the yard up and tensions the luff, and the downhaul goes straight up to the yard, raised the head and tensions the sail the leach. It gives a very high peaked lug. ...

--- I do not understand then how the luff gets adequate tension. It has been my understanding that, in most cases, the halyard is not adequate to tension the luff alone on a standing lug....? -- Wade

[keyhavenpotterer]

Good point Wade. I will have to do some more snooping next time I see them launching! Remember though the pull down on the front of the yard and the luff tension have been separated. The yard is very vertical so perhaps it is high enough on the halyard for the downhaul to be tensioned enough. The free luff can be as full as the sailmaker wishes?

Brian

[Dryfeet]

What is the largest size that might be reasonable for a boat? (Sail area) It seems that with a few, ahem, adjustments, it might work for bigger boats. Typically, that's when junk rigs start to be seen but I'm interested in the balanced lugs, perhaps with battens. Thoughts?

[Todd Bradshaw]

I think the biggest balanced lug that I've built was about 130 sq. ft. for a sharpie, but I generally specialize in small sails these days and don't go after the larger sail market. I'd feel a little more comfortable with a big standing lug than with a big balanced lug. The reason is that you can usually induce more upper-sail twist to leeward when desired on a standing lug. This gives you more ability to depower the rig in high winds, as well as a bit of a built-in shock absorber in gusty conditions. The balanced lug configuration doesn't do these things as well. On the other hand, it will most likely work better than the standing lug on a run because it spreads the sail area out more evenly, port and starboard of the mast. I suppose it would boil down to how much sail area you have vs. how tender or stiff the hull is in high winds.

You can obviously make some darned big lugsails without going the Chinese Lug route and this "Stack-O-Lugs" idea would make for a really interesting boat.

http://lh6.ggpht.com/_3hVz19OqxTQ/SJDF9KKtOdI/AAAAAAAACzA/FnOSMW6fEHQ/s640/A9469-BREST%202008-CANCALAISE-web.jpg

[keyhavenpotterer]

And this new design by Francois Vivier 144 sq m

http://www.vivierboats.com/Img/paimblotine.png

Lots more here

http://www.vivierboats.com/html/heritage_decked.html

Brian

[wtarzia]

... On the other hand, it will most likely work better than the standing lug on a run because it spreads the sail area out more evenly, port and starboard of the mast. ...

--- The balanced lug then might be a great choice for a motor-sailer, whose skipper might motor to windward and to maneuver but enjoy sailing on other points? (And I recall Phil Bolger writing that a dipping lug, close cousin to the balanced lug, made a good choice for a motor-sailer). -- Wade

[Loose Moose]

I often wonder if anyone has really sailed with a proper Balanced Lug rig on anything larger than a dinghy...Because so much of the advice, comments and info is just so off base.

We sailed thousands of miles with a Bolger designed Balanced lug rig sharpie and it is most certainly not a rig just for motor sailers...

Fact is it can be a great rig and very weatherly if the person designing the rig has a clue and you luck into a sailmaker who actually knows how to cut and sew a proper lug.

More so it is just about the best bang for the buck that you can find in terms of performance for investment on what is a very docile and easily handled rig.

Bob

http://boatbits.blogspot.com/
http://fishingundersail.blogspot.com/
http://islandgourmand.blogspot.com/

[Clinton B Chase]

I'd feel a little more comfortable with a big standing lug than with a big balanced lug. The reason is that you can usually induce more upper-sail twist to leeward when desired on a standing lug. This gives you more ability to depower the rig in high winds, as well as a bit of a built-in shock absorber in gusty conditions. The balanced lug configuration doesn't do these things as well. On the other hand, it will most likely work better than the standing lug on a run because it spreads the sail area out more evenly, port and starboard of the mast. I suppose it would boil down to how much sail area you have vs. how tender or stiff the hull is in high winds.


I think this point Todd makes is the essence of standing and balance lug sails. One way to deal with the fact that a BL is harder than a SL to twist off to depower is to make sure the yard is not to stiff. If it allowed to bend, it will spill some air a loft. Someday maybe we can pool our experiences/experiments to come up with a flex test result that we can use to compare rigs. For now, the yard should be just right flex wise. I recently did one for a Goat Island Skiff. I felt it was too flexi with the Spruce I was using and plan to beef up the dimensions. The trick is by how much.

I think SL's are great in small boats that are tender like dinghies and dories and the like because they are tender and to depower quickly is key to stability. I think Todd made a great point.

Clint

[wtarzia]

...We sailed thousands of miles with a Bolger designed Balanced lug rig sharpie and it is most certainly not a rig just for motor sailers...

--- I don't think anyone said it was just for motor sailers. I suggested it might be a good choice for one, though. -- Wade

[Todd Bradshaw]

Likewise, I don't think anyone is bad-mouthing balanced lugs. However, there are some well known differences between the in-use characteristics of the different varieties of lugsails and it would be foolish to ignore them. Each type is a compromise of some sort and none is perfect for all applications. If we really wanted to ignore their weaknesses and concentrate only on their strengths, then we would probably all be using dipping lugs because of their greater efficiency once you get the darned thing dipped.

As for spar bend, it's a matter of making choices and doing your best to match the sail to the spars. There is no generalized "correct" amount of bend, just as there is no correct amount of head round to deal with bend. We start with the assumption that the spars are, and will stay, completely straight in use. The sail is designed with allowances and seam-shaping to provide the proper draft amount and draft location for straight spars. However, if we actually build the sail that way, it will most likely be a performance failure. When our real life spars start bending from wind pressure, mainsheet tension, etc. the first thing that this bending will do is eat up the allowance we built in for draft, making the sail completely flat. For most purposes, we want our sail to have it's designed draft in moderate conditions, so we build-in an additional allowance that will allow moderate spar bend yet still maintain proper draft. In heavy air, or conditions where we are sailing upwind and sheeted in tightly, more bending force is applied to the spars, they bend more and eventually eat up both the draft allowance and most of our bend allowance, again flattening the sail. In those conditions, we actually want a flatter sail, so this is good. However, if the forces bend the spar too far (beyond the combination of our designed draft allowance and the bend allowance) the sailshape quickly goes down the tubes. It will usually manifest itself in a big, tight, vertical wrinkle running up and down the center of a 4-sided sail and excessive looseness along the luff and leech. The sailshape has essentially turned inside-out - no draft in the middle and floppy edges instead of firm edges and draft in the middle.

If we know that a sailor usually sails in a windy place, or in sheltered, light air conditions, then we can adjust the bend allowance to try to match his typical sailing conditions. The heavy-air sailor will get more allowance to handle more wind and spar bend and the light air sailor will get less because his sailing conditions won't usually create as much bend. The "I don't know yet" or "I'll sail in all conditions" sailor will usually get a medium bend allowance. None of these three sail cuts (heavy-air, light-air or all-around) will be perfectly cut for all conditions and the more whippy your spars are, the harder it is to predict how much bend allowance to add. This is the reason that if you order a sail kit from a place like Sailrite, they will ask you about the wind and water conditions that you are most likely to be sailing in. They're not just curious, they want to get some sort of feel for how much draft and how much bend allowance they need to punch into the computer to make the best shape compromise for your particular situation. It's not unusual for the amount of round added to a sail like a lug along its head edge to be a combination that's about 25% for draft creation and 75% bend allowance to try to maintain that draft.

This is by far, the most tricky part of cutting a good sail - especially for small boats where some of the spars may not be much more rigid or substantial than a hunk of closet pole. There is no question that the boat will sometimes be sailing in conditions that don't match the sail's bend allowance and the sailshape will suffer for it. Whether you cut the sail by eye or with the best computer design systems and plotters, the spar bend allowance can only be an estimate. One thing that will normally help generate good sailshape is tapering your yards and booms at their ends. This has the effect of proportionally stiffening their middle (the place where bend is most prominent and usually least desirable). Another is avoiding mid-boom sheeting, which tends to bend booms in the middle and can reduce designed draft on a laced-footed sail and increase it on a loose-footed sail. No matter who cuts your sail though, understand that the shape and bend allowance are a compromise and always will be, and the better they match up with the particular spars for that boat, the better your all-round performance will be.

If you ever get a chance, go sailing on a Starboat. The mainsail has a fairly large luff curve and the mast is a 30+ foot-long noodle. They combine these with uppers, lowers, spreaders, a mast ram under the deck, jumper stays, dual adjustable headstays, a big radial boom vang with traveler cars, a mainsheet traveler and upper and lower running backstays on tracks running fore and aft on the deck - and all these are controllable through banks of cam cleats at your fingertips. Star sailing is all about spar bend control and your ability to tune it in or tune it out in micro-increments is just amazing. The mains are very large, but don't have reef points. If you need to depower, you adjust power out of the main using mast bend and sail twist. You can be sailing along and think "Gee, I'd like to have about 1/2" more mast bend for a slightly flatter sail and I'd like it to be just in the top third of the mast". Pull a couple strings and you have it. Round the next mark, ease them and pull something else and you can create a totally different shape. My old Starboat was in many ways, a total pain in the ass to own and launch - but once you got it off the ramp, out of the harbor and into open water, it was truly amazing to sail and an awfully good learning platform. It's no wonder that so many of the America's Cup skippers and mainsheet trimmers spent a good deal of time in the Star class. It's like a masters class in sail shaping.

[Thorne]

Not to muddy the waters, but you could always "split the difference"...
http://www.luckhardt.com/marshall3.jpg

Great thread, thanks Todd and you others for stuff like this!

[Loose Moose]

Forgive me if my post last evening sounded a bit harsh...The oft and mis-used damning with faint praise quote by Phil Bolger is something of a trigger for me...

Bolger was a huge proponet of the various Lug sails and it galls that I am often met when mentioning Lug rigs with responses like "But even Phil Bolger says its only good for motor sailing and you can't tack etc."

Which of course is not what Phil Bolger said... ever. But I hear it time and time again from a lot of people who really should know better.

The other trigger for my knee jerk reaction is that sails get real different when they get bigger and once you start using sails of 300 square feet and over they simply become different animals. So do the boats you put them on...

The minute I read this thread yesterday I knew that today I would wake up to at least three emails from "friends" telling me that I should check out the forum because there was a thread that supported their Lugs just don't make sense agenda...In fact I had five emails this morning telling me just that.

So anyway no offense meant simply ongoing frustration of being huge fan of lug rigs both big and small...

Bob

http://boatbits.blogspot.com/
http://fishingundersail.blogspot.com/
http://islandgourmand.blogspot.com/

[Todd Bradshaw]

Thorne, that split lug is really neat. I could easily spend the rest of my life building unusual sail types like that one, just to see what they would do out on the water. The problem is always the time and cost involved building proper boats to hang them on. I'd still like to try something along the lines of this concept on a canoe or dinghy some time to see what it does. There is a wild and crazy group of Australian sea kayak sailors who sail in high winds and big surf and I saw a photo of one using a similar rig. From what I could gather, they pretty much set it, cleat it, hang a high brace out to windward to "hike out" and steer with the brace.

http://webpages.charter.net/tbradshaw/LUGV%20copy.jpg

Loose Moose, welcome to the forum. I just scanned through this entire thread again, wondering what it was that you seem to find so offensive. Perhaps I'm "battle-hardened" around here, but my overall impression is that the thread is for the most part quite complimentary to lugsails, their performance and their versatility. I'm certainly not seeing anything which in any way resembles a "lugs don't make sense agenda" or could even be twisted into one and am wondering where you came up with that idea??? If you think this thread reflects any sort of harsh criticism, just stick around, you ain't seen nothin' yet.

You have made two posts on the forum. The first one basically said that the rest of us don't know what we're doing. The second one is tilting at windmills and attributing statements like the agenda and Bolger comments, presumably to someone in this thread - when no such comments exist, or were even hinted at in the thread. If what you're reading here is causing some sort of "knee-jerk reaction" and an off-the-wall post or two, then perhaps there is something wrong with your eyes or your knees :) and at this rate, you probably won't last long around here. A goodly number of the folks who have contributed to this thread (and those you insulted with your first post) actually own and sail boats with lugsails. Some may even have far more experience with them and with the various types of lugs than you do. To a couple of us, like John W. and myself, putting people in lugsail equipped boats that work properly has been an integral part of our businesses for many years.

The original poster on this thread posted his question because he is interested in learning about lugsails and the possibility of using one on his boat. I don't believe anyone has said anything to discourage him. If you have something to share in detail from your sailing experience that might help him or technical expertise to contribute, we're all ears. He would probably appreciate the help and it might contribute to an interesting discussion. So far though, you're 0 for 2 and any "frustration" you're feeling is of your own manufacture. Just a hint...but folks who tend to jump into threads around here out of the blue and do little more than make a couple of quick, insulting comments often earn a reputation as blow-hard jerks and get put on the ignore lists of the other forum members (sub-hint - the old "I have one and it works fine" with no additional data offered doesn't usually make a very convincing argument in support of a product, since it can often be easily countered with a simple "compared to what?"). We would all welcome any thoughtful, helpful or interesting contribution you would like to make to the thread, but to be honest, the forum already has more than enough whacko posters who do nothing more than jump in, make a couple quick insults and leave the rest of us wondering WTF is up with that guy?

[JimD]

http://webpages.charter.net/tbradshaw/LUGV%20copy.jpg



Todd, that is too cool. Can it be reefed?

[slidercat]

Speaking of dipping lugs, has everyone seen this amazing little video?

http://www.youtube.com/watch?v=Y-Gp71JdmPs&feature=channel

Evidently this technique was and is used by luggers from the town of Beer in Devon. This ingenious guy adapted the idea to his own small boat.

Here'a hotlinked pic of an original Beer lugger, which I hope the Devon promoter will not mind.

http://www.beer-devon.co.uk/BeerHeritage/BeerHeritageSite/VillageSite/pictures/Lugger1.jpg

It's an interesting rig. The luff seems to be laced to a spar (vo'g'rd) that's hinged to the yard in the old Beer luggers-- maybe this helped with the unusual tacking technique, but I don't really know.

Expect to have to watch the video more than once to figure out what's happening here. It took me several run-throughs and it made my brain ache a little. But it's brilliant, and would make the use of this beautiful and powerful sail much more practical.

[T. Traddles]

That gentleman's boat was featured in Watercraft magazine a few years ago. I would love to see a drawing of the arrangement that makes that possible. I've watched that video several times and still cannot tell how he does it precisely.

Also, and just as an aside, I have a copy of Leather's Spritsails and Lugsails and there is no detail drawing or discussion of this arrangement as far as I can tell. This is just too bad.

Finally, the split lug above has little peak to it, while Oughtred's balanced lugs have a very high peak. What are the ratios (eg., luff to foot, etc) that determine the sails shape and which ratios are optimal for the balanced lug?

[Todd Bradshaw]

Jim, I haven't really pondered the design much and simply made a quick sketch of the concept a couple years ago in case I lost the photo (I see that I left out the downhaul, which I would assume to be similar to that on any balanced lug and a rather simple, but critical, part). Top of my head, I'd think that you could run a reef line across both sails at the same level above the main boom, tie them in and hoist the yard to a lower altitude to reef it.

For a dinghy, canoe, kayak, or maybe even a small, traditional-looking iceboat rig, the sails would have pretty tiny additions for draft and I guess, some sort of forward-weighted-yard-bend-allowance for the "mainsail" portion and a tiny, mid-weighted bend allowance along the "jib" portion's head. They could probably be cut dead flat from polytarp or Tyvek with nothing more than the bend allowances added as head-round just to try out the concept. If it worked, the draft could be calculated for a more sophisticated version from better fabric later. It's just one of those designs that grabs your attention because it looks like something really clever and worth trying - and anyone who owns a balanced lugsail already has a set of spars that would probably fit the bill for testing with the addition of a couple of sticks for the jib yard and boom.

As for optimum peak angles for lugsails, I'm not sure that there are any specific guidelines, though getting the peak angle too far toward one extreme or the other is most likely going to result in decreased performance or problems keeping the configuration in the proper shape once it's hoisted and you're out on the water. Sailmakers are usually building to a profile given to us by a designer. Our job is simply to make sure the construction and 3-D translation of the plan works. On a one-off with no designer's sailplan or a design-from-scratch situation, we generally stick pretty closely to a profile that we know has worked well in the past on similar boats. Making a sail once and then having to take it apart and rebuild it to a different shape because one got a bit too creative in the design phase is a lousy way to make money. Over time, you develop your own favorite profiles that seem to have a combination of good all-round performance and a pleasing look.

I don't know whether John, Iain Oughtred or other designers who turn out a lot of lugsail-rigged designs have any specific guidelines that they follow for peak angles on their lugsails or not.

[gert]

I don't know whether John, Iain Oughtred or other designers who turn out a lot of lugsail-rigged designs have any specific guidelines that they follow for peak angles on their lugsails or not.

Let's hope they do :) otherwise I'm in trouble :eek:

Which begs the question:

Would a sailmaker know if a sail plan was "right"? And would he correct it if it wasn't?

After reading this thread I'm going home to fiddle with my lug; it's always had a loose luff, partly because (I beleive) it's on a goose neck and I depend on the halyard for tension; and that's just not enough. I think I'll try a side jaw and downhaul.

[Woxbox]

Todd -- That trick balanced lug-with-a-jib looks like it would be self-tacking, right? On a bigger boat, just have it sheeted amidships and put the tiller down to tack?
It comes across as an early but simpler version of the Aerorig, which carries jib and main on one long rigid boom that's fixed to a rotating mast. I see all sorts of advantages -- the sheet load would be minimized, for example. Hmmm.

[Daniel Noyes]

Forgive me if my post last evening sounded a bit harsh...The oft and mis-used damning with faint praise quote by Phil Bolger is something of a trigger for me...

Bolger was a huge proponet of the various Lug sails and it galls that I am often met when mentioning Lug rigs with responses like "But even Phil Bolger says its only good for motor sailing and you can't tack etc."

Which of course is not what Phil Bolger said... ever. But I hear it time and time again from a lot of people who really should know better.

The other trigger for my knee jerk reaction is that sails get real different when they get bigger and once you start using sails of 300 square feet and over they simply become different animals. So do the boats you put them on...

The minute I read this thread yesterday I knew that today I would wake up to at least three emails from "friends" telling me that I should check out the forum because there was a thread that supported their Lugs just don't make sense agenda...In fact I had five emails this morning telling me just that.

So anyway no offense meant simply ongoing frustration of being huge fan of lug rigs both big and small...

Bob

http://boatbits.blogspot.com/
http://fishingundersail.blogspot.com/
http://islandgourmand.blogspot.com/

feel free to let loose with both barrels :)

I am trying to figure out the appeal of the Lug

As the wind pressure on a lug increases it tends to bow the mast, as the mast bows this slackens the uphaul/downhaul tension on the sail causing the sail to bow and belly, the extra shape that is allowed into the sail just as the wind gust hits allows the sail to become more powerfull and generate even more heeling power just at the wrong moment.
Hence the need to reef these sails early and often.

compare a lug of 120 sq ft to a Leg-O Mutton dory rig, evolved over several hundred years in conjunction with a light narrow hull.
the dory sail has no reefs the lugg will have 2 or even 3 reefs!

The modern lugs mentioned above for use on light narrow craft are really quite modern. carbon fiber spars, dacron sails, and multiple purchases on the down haul, all these innovations help flatten these sails and controll this powerfull but potentially unrully sail.

But... it seems like a lot of work to force a lug to do what other traditional rigs do so easily.

The rig for a cat yawl with modern (1990's-2000) Lug has 6-7 spars (how many linear ft. of hollow or composite spars?) and uses extreme internal tension and 2-3 sets of reef points to keep the sails manageable. (double and even tripple purchase down haul) and relies on the wonderfull characteristics of modern sail cloth to resist the extreme forces working to pull the sail out of shape.

The dory rig well over 100++ yrs old uses 2 spars (30 +- linear ft. of simple solid wood spars) down haul tension is a simple line cleated and no reef points. to set a similar amout of sail area with a similar degree of controll and seaworthyness and sailing performance.

[RodSBT]

I'm still learning; which lug rig would this be?

http://www.youtube.com/watch?v=KnEBACCkI-g&feature=related


And thanks for all the great info.
Lots to think about.

[David G]

I'm still learning; which lug rig would this be?

http://www.youtube.com/watch?v=KnEBACCkI-g&feature=related


And thanks for all the great info.
Lots to think about.

That one appears to be a standing lug - where the forward end of the boom only reaches as far forward as the mast.

[David G]

I am trying to figure out the appeal of the Lug

As the wind pressure on a lug increases it tends to bow the mast, as the mast bows this slackens the uphaul/downhaul tension on the sail causing the sail to bow and belly, the extra shape that is allowed into the sail just as the wind gust hits allows the sail to become more powerfull and generate even more heeling power just at the wrong moment.
Hence the need to reef these sails early and often.

compare a lug of 120 sq ft to a Leg-O Mutton dory rig, evolved over several hundred years in conjunction with a light narrow hull.
the dory sail has no reefs the lugg will have 2 or even 3 reefs!

The modern lugs mentioned above for use on light narrow craft are really quite modern. carbon fiber spars, dacron sails, and multiple purchases on the down haul, all these innovations help flatten these sails and controll this powerfull but potentially unrully sail.

But... it seems like a lot of work to force a lug to do what other traditional rigs do so easily.

The rig for a cat yawl with modern (1990's-2000) Lug has 6-7 spars (how many linear ft. of hollow or composite spars?) and uses extreme internal tension and 2-3 sets of reef points to keep the sails manageable. (double and even tripple purchase down haul) and relies on the wonderfull characteristics of modern sail cloth to resist the extreme forces working to pull the sail out of shape.

The dory rig well over 100++ yrs old uses 2 spars (30 +- linear ft. of simple solid wood spars) down haul tension is a simple line cleated and no reef points. to set a similar amout of sail area with a similar degree of controll and seaworthyness and sailing performance.

Mr. Noyes,

I own two small boats - both with balanced lug rigs. One is 85 sq. & the other is 105 sq.

I'm not a sailmaker, but can speak a bit about the appeal of Lugs.

First - in contrast to the picture you paint, the traditional lug rig is one of the simplest there is. And, as a result, quite inexpensive to set up. It does require a mast and two other spars, but the hardware is quite minimal, and the lines as well.

Second - it's powerful. You can get a lot of drive for the size of boat.

Third - it's less inclined to overpower a boat. The center of effort is lower than most.

Fourth - versatility. It's quite easy to reef. This allows you to set a lot of canvas, and sail in light airs - or go with a full spread, and really rip it up - or reef when it starts to be a bit much.

Fifth - safety. The same easy reefing also encourages recreational sailors to reef when necessary, as opposed to reefing when it's a bit too late, and you're under duress. Also - because of the geometry of having part of the sail forward of the mast - gybing is less harrowing and tipsy.

Sixth - laziness. There are very few lines to tend. The downhaul makes it substantially self-vanging - eliminating another complication. Bolger describes the balanced lug as "...docile and effective broad-reaching and running... light to sheet and self-trimming from tack to tack" He says it holds a good shape on all points of sail.

Seventh - spar length. Generally, all the spars for this rig will fit inside the boat. As I'm sure you can imagine, that's handy in a lot of ways.

Eighth - looks. Aesthetics are very individual, but I love the look of a balanced lug. The only thing that tickles me as much is gaff rig.

A well-designed lug rig does NOT power up at exactly the wrong time, as you describe. In fact, if the yard is the correct thickness and taper, it can be engineered to depower in a gust.

For more, I'll repeat Songolo's suggestion to check out Michael Storer's writings and designs:

http://www.storerboatplans.com/Faq/tradrigperformance.html

You might also be interested in Bolger's book comparing a wide variety of small boat rigs.

http://www.abebooks.com/servlet/SearchResults?an=phil+bolger&sts=t&tn=100+small+boat+rigs&x=86&y=17

[Todd Bradshaw]

RodSBT
It's a cross-cut, loose-footed Standing Lugsail. That's a great video if for no reason other than that a hell of a lot of non-lug users probably have no idea that a lugsail can work so well and move a light boat that fast. It's spreading a goodly amount of sail area in a fairly low, short-masted package, yet getting a good deal of that area up high, where the wind is. The rig is nicely matched to the hull and can sail with full sail up in good sailing winds and move the boat well, while the sailor can still balance out the heeling forces with the tiller and moderate hiking. Combine that with a rig that can drop the main to the deck nearly instantly if needed, and you have a pretty efficient and fun sailboat.

Pause the video at about 38 seconds and look at the mainsail shape. Notice that he is using upper yard and sail twist to leeward as a shock absorber and to de-power the top of the sail somewhat (most likely by tightening up the rope traveller and then easing the mainsheet a bit, but I can't tell for sure). This type of induced twist would be less possible on most balanced lugs, as they tend to swing more like a barn door, with their yards and booms usually staying pretty close to parallel. This twist control, as I mentioned above, is one of the things that standing lugs do quite well. In order to do so, they sacrifice the self-vanging nature that the balanced lug configuration offers (helps keep the boom's tail down and the entire sail working from top to bottom at all times by preventing twist) but every sail type has it's strengths and concessions.

Now pause at about 1:00. The traveller would now seem to be eased somewhat and the mainsheet tightened, but pulling down farther outboard. As you can see by looking up and down the leech, the sail twist to leeward is now nearly all gone as a result. You will also notice in this area of the video that much of the shock absorbency that the twist was offering is gone and the boat tends to rock more severely in puffs. It's one of those spots where you have to decide whether your boat moves faster by sailing smoother, with less rocking by putting in some twist, or by allowing it to rock a bit more in the puffs, but keep more sail area pulling hard all the way up and down the sail by eliminating twist. Keep in mind that it's pretty much impossible on any sail to eliminate 100% of the twist up high - which is actually a good thing because the wind itself is twisted a bit at the top of the mast, compared to its direction at the boom.

I love the little reaching spinnaker. The mainsail leech is a little tight off the wind, but obviously, the boat is moving along quite well. I mentioned to Loose Moose this afternoon, off forum, that a lot of modern sailors seem to think lugsails are some sort of out-dated, quaint antiques that couldn't possibly perform very well. The folks who own lugsail-equipped boats usually have a very different perspective on the issue and a video like this might open some eyes of the non-believers. They certainly aren't the hands-down choice for every sailboat, but they can be quite capable on the right one.

Gert,
The designers may have a formula for peak angle, though I suspect it's more likely that they generally stick pretty close to profiles that have a proven track record. I'm not a yacht designer, but I get the feeling that making some comparisons to known boats and their performance characteristics is often an integral part of designing many recreational boats. No need to re-design the wheel if your intent is just to polish it a bit and tweak the styling.

Q: "Do sailmakers know whether a sailplan is right and change the design if it isn't?"
A: In most cases, we have to trust most of what the designer has done in terms of rig details, plan profile, balance, etc. We don't have all the figures to determine some of these aspects - heeling characteristics of the hull, for example, and often even the location of the CLP. We have to assume that the designer knows what he's doing and that somebody, somewhere has actually tried the boat or at least run the numbers on it and it works, or should work, pretty much as advertised.

Construction details for the sails are a different story. There are often questionable details on the sailplans of even some of the best boat designers (bad panel layout schemes, improper corner designs, etc.) Designers aren't usually sailmakers and have more important things to worry about. If I find something like that, I'll notify the boat's owner of the problem and explain to him why it needs to be changed. Usually it's a matter of "this detail isn't strong enough to last" or "this threadline/panel layout is going to stretch out the leech quickly" and the fix is pretty painless. So far, in 29 years of making sails, I haven't really run into a plan where I felt there was something totally, crazy-wrong and not fixable which would totally screw up the boat's ability to sail.

Wox,
Yes, the little sloop-on-a-stick rig should be self tacking. Also, if the main boom was lengthened a bit in front (enough to allow the jib's downhaul/tack-to-main-boom lashing to be attached around 20%-25% of the jib boom's length from its forward end, then the jib would also be self-vanging - like the jib on a radio-controlled model sailboat. This helps eliminate boom lift and excessive sail twist on a sail where you don't have anything more than a single sheet controlling its trim and sailshape. This also brings in another interesting possibility. The RC sailboat-style, self-vanging jibs were also used on full-sized Ice Scooter iceboats. The jib was the rudder and the boats were steered by trimming or easing the jib, allowing the driving forces and the rig's C.E. to pivot around the mast as jib trim changed. On a little boat like a dinghy or canoe, it might be possible to do most or even all of your steering with jib trim alone. As I said, it looks like it could be a very interesting rig to play with.

[wtarzia]

Speaking of dipping lugs, has everyone seen this amazing little video?....

--- I watched it over and over and couldn't figure it out. I did think I wanted to see the wind pressing the sail up against the mast Iie, real world) and see the technique completed. -- Wade

[T. Traddles]

I'm still learning; which lug rig would this be?

http://www.youtube.com/watch?v=KnEBACCkI-g&feature=related


And thanks for all the great info.
Lots to think about.

That is a nice video. I think the boat is a Joel White PoohDuck Skiff, and she is really moving along nicely. Isn't it unusual to fly a foresail when flying a lug main on small boats? Also, did you notice the wrinkles of the sail at the clew of the main? Is this a problem with regard to the set of the main?

[keyhavenpotterer]

Fairly normal to have a foresail around here! Note the front of the boom is strapped, with a loop of line, to the mast when using a jib. This prevents the jib constantly catching on the front of the boom when tacking.

http://www.johnclaridgeboats.com/SCOWS/sCOW2-1.JPG?0.8235178291227618

Brian

[T. Traddles]

Fairly normal to have a foresail around here! Note the front of the boom is strapped, with a loop of line, to the mast when using a jib. This prevents the jib constantly catching on the front of the boom when tacking. Brian

Brian, looking at the scow's rig and seeing that there is little sail area before the mast at boom level, the rig seems more like a standing lug rather than a balanced lug. And this appears to be the case even when not flying the jib. So, what do you folks consider the sail to be?

Also, how effective is flying the jib from the unstayed mast. From the pictures I've seen, the mast seems stiff enough to be able to maintain a fairly taught luff on the jib.

Whoops, my bad! Looks like there are stays. Powers of observation waning, must drink more beer!:-)

[Daniel Noyes]

--- I watched it over and over and couldn't figure it out. I did think I wanted to see the wind pressing the sail up against the mast Iie, real world) and see the technique completed. -- Wade

Me too,
imagine tacking a jib on a sloop rig by hauling the jib around infront of the forestay...


David G
First - in contrast to the picture you paint, the traditional lug rig is one of the simplest there is. And, as a result, quite inexpensive to set up. It does require a mast and two other spars, but the hardware is quite minimal, and the lines as well.

I agree with that but lots of lugs being discussed/ built now are these ballanced/standing lugs wich seem to be more complicated (ie hollow masts, multi purchase down haul, modern low streach lines, etc)
I dont think a lug is any simpler than a traditional lateen, sprit, Leg-O-Mutton, etc.


Second - it's powerful. You can get a lot of drive for the size of boat.

Point taken, this would seem to be a big advantage in centuries past when good sail cloth was extremely expensive and the maximum drive for the expenditure on cloth may have been a consideration.


Third - it's less inclined to overpower a boat. The center of effort is lower than most.

Do these modern lugs have a lower center of effort than a gaff, sprit, or L-O-M rig? the sails seem quite narrow and tall... hence the need for reefs?
The dory rig I sail (L-O-M) sets 150 ft. on a 19.5' mast but the boom is 18'... the center of effort is only about 8-9 ft above the mast step, 6-7 ft up from the bottom of the sail.

Fourth - versatility. It's quite easy to reef. This allows you to set a lot of canvas, and sail in light airs - or go with a full spread, and really rip it up - or reef when it starts to be a bit much.

How is it lowering the yard to reef? can the sail act wild as the spar comes down and the sail looses tension?, most sails are attached to the mast and will just flap like a flag as they are lowered, the lug is more like a jib wich can flog in the wind.

Fifth - safety. The same easy reefing also encourages recreational sailors to reef when necessary, as opposed to reefing when it's a bit too late, and you're under duress. Also - because of the geometry of having part of the sail forward of the mast - gybing is less harrowing and tipsy.

More a question of Seamanship, skill and judgement than the effect of a particular rig?



Sixth - laziness. There are very few lines to tend. The downhaul makes it substantially self-vanging - eliminating another complication. Bolger describes the balanced lug as "...docile and effective broad-reaching and running... light to sheet and self-trimming from tack to tack" He says it holds a good shape on all points of sail.

Most main sails are self tacking... an exception being the dipping lug.


Seventh - spar length. Generally, all the spars for this rig will fit inside the boat. As I'm sure you can imagine, that's handy in a lot of ways.

I like to get the spars out of the boat as much as possible, makes more room for crew etc. I can fit the spars inside the dory but seldom do... would this be a consideration in rig choice.

Eighth - looks. Aesthetics are very individual, but I love the look of a balanced lug. The only thing that tickles me as much is gaff rig.


There all beautifull!

[T. Traddles]

In Bolger's 103 Sail Rigs, he mentions that the standing lug is at least as effective as a gaff rig, but then notes that the balanced lug has a better driving shape than the standing lug. Would this not make the balanced lug a better sail than either the standing lug or gaff?

[slidercat]

--- I watched it over and over and couldn't figure it out. I did think I wanted to see the wind pressing the sail up against the mast Iie, real world) and see the technique completed. -- Wade

I haven't looked at a frame by frame of the video to be sure, but here's my take on what's happening: In essence, the sail is turning inside out. As the sheet drags the clew over the luff, the leech pulls the top of the yard around the mast.

David mentioned in another forum that there's a bit of skill and timing involved in tacking the sail, and that it may hang up and have to be shaken loose if you don't pay attention. This would worry me a little, especially in a larger boat, but the Beer luggers are pretty substantial boats and set a lot of sail, so it must be possible to tack pretty reliably.

I've always been drawn to the dipping lug. It's a powerful and beautiful sail, sets a lot of area on short spars. If you don't have to dip it, it becomes a very attractive alternative to other lugs. Of course, it isn't self-tending, a drawback. But on the other hand, it's probably no more trouble than tending jib sheets, and a lot of us put up with that. That it's boomless is another issue. I've wondered if, with a beamy boat like a cat, if you couldn't put the tack of a dipping lug on a traveler and make the sail more efficient off the wind.

Another interesting thing I've seen by looking at pictures of the Beer luggers is that they brail the sail up to the joint between the forward end of the yard, and that odd spar that the luff is laced to. It seems a very good working boat rig.

The burning question is: is it still a dipping lug if you don't have to dip it?

[wtarzia]

In Bolger's 103 Sail Rigs, he mentions that the standing lug is at least as effective as a gaff rig, but then notes that the balanced lug has a better driving shape than the standing lug. Would this not make the balanced lug a better sail than either the standing lug or gaff?

--- On one tack, it is close to the dipping lug, but on the other with the front part aback against the mast?

Of course, the standing lug has mast interference problems of its own, especially when spoiling the wind on the more sensitive lee-side of the sail. I know some people "dip" the yard around the mast with a dipping line on the yard heel to always get mast to windward. I've tried it a few times, but when the sailing is any good at all, it wasn't worth the time and disaster potential (I sail an outrigger canoe, which is stable, but the "bandwidth" of its safety margin is narrower than that of a monohull; perhaps dipping is OK on a slow day).

But there always seems to be a "however." A fellow on my other sailing discussion group has done windtunnel research at a German university, and he claimed that when the mast is on the lee-side of a standing lug, it remains safely within the lee leading-edge circulation bubble for the most part, so its detriment is not too bad. Perhaps this finding might apply to balanced lugs, in that, on the sail-aback tack (mast to lee), the pressure side of the sail is less sensitive to disturbance, and on the sensitive lee (suction) side, the mast already dwells in a somewhat disturbed zone? -- Wade

PS -- Wandering aside to the sprit rig -- I have always heard (from pro and amateur alike) that a sprit sail sprit, when it cuts the sail on the lee-side, "does not affect performance too badly" or "doesn't make as much difference as you might think" and etc. I still do not understand why even if "it is just that way." I suppose the peak is in the zone of bad air anyway, and the some of the tack-end is close to the bad air near the mast, but there's that primary power zone of the sail cut across on the bad tack.

I used a home-made sprit briefly -- loved the way it brailed up and stowed, one of the most kindly set-up/take-down/tame it sails I have used....but that diagonal slash disturbed me. (Since a mizzen sail is generally operating in disturbed air any way, I wonder if a sprit is a good choice for that position?). (The Polynesian sprit gets around this problem (if it exists) by cutting away the sail under the sprit, making the sprit into a boom, so that as the sail tacks, clean airflow always exists on the lee side as the sail bellies past the sprit-boom. But you can't reef it easily.) --wt

[Captain Blight]

Great thread. A couple questions come to mind for this tugboat deckie:

(1) There seems to be a clear family line from the traditional squaresail to the dipping lug to the balanced lug to the modern flat-headed jib; I'm sure the lateen fits in there somewhere but I wouldn't know where to place it in the continuum. So how much of the question of which boat gets what rig is dictated by hull design/design parameter, and how much of the hull design is informed by the rig?

(2) I recall reading something on the Boatdesign.net forum about a modern variant of the lug rig that used a masthead offset, just a short, right-angled masthead piece about a foot long, to place the upper yard well to one side of the mast. It seems to me that this would offer a number of advantages, primarily keeping the belly of the sail well clear of the mast (on one tack) and out of the mast's draft (on the other... well, maybe both tacks). Anybody know what I'm talking about here? Anybody have experience with this?

[wtarzia]

[quote=Captain Blight;2318183... I'm sure the lateen fits in there somewhere but I wouldn't know where to place it in the continuum. So how much of the question of which boat gets what rig is dictated by hull design/design parameter, and how much of the hull design is informed by the rig? ... I recall reading something on the Boatdesign.net forum about a modern variant of the lug rig that used a masthead offset, just a short, right-angled masthead piece about a foot long, to place the upper yard well to one side of the mast. ... [/quote]

--- As for the lateen, I would guess it evolved from the square sail (or rather the rectangluar sail?) of the ancient world, just as the ancient Northern square sail evolved into dipping lug and gaff, etc. Sail evolution always makes good chat, and I wish I could be face to face with fellow speculators and a pot of beer. The evolution of the Polynesian "crabclaw" sail occupies the last part of of Horridge's excellent "Outrigger Canoes of Bali and Madura, Indonesia" and is a good model to explore (I am a true believer in cross-fertilization).

Now, the relationship of the Northern European square sail to the ancient world is interesting. I do not believe we have evidence of masts in the Northern area until quite late (7th century? Later? Early lapstrake boats do not seem to have had true keels or mast-steps; that is not to say that some more flexible mast set-up didn't exist that would leave little trace on boat structure [picture a bipod mast lashed to gunwale or thwarts], but again, not aware of evidence for that) so most people would say that Roman and post-Roman influence flowed up to inspire the North. I am always a little suspicious of diffusionism (because it removes ingenuity from some "native" culture) but it does exist, so who knows? The existence of enough sheep near maritime communities would be important. I confess I know nothing about the growing of flax for making fabrics, though, in early medieval times.

For the lateen I would ask, "Did the Mediterrean (I know I am misspelling this) have wind patterns that would encourage development of the lateen from the square sail?" Greater needs for windward work?

Concerning hull style correlated to sail rig -- I guess a tender boat encourages the low-aspect rigs; or "tender" materials -- for low-tech materials you might want a sail that spreads its stresses more generally/widely around the fabric. Todd? Would lugs do that releative to higher aspect marconis? The Polynesians designs did tend to spread stresses widely -- they had no metal and only coir and mat-sails. Note that the Polynesians and their outriggers did develop some high-aspect rigs, though traditional outriggers were not necessarily very wide (they ran intomaterials strength limits and had to keep some of the canoes narrower than a modern designer would; lashings offered stress relief, as well as just lowering or brailing sails in a blow).

The frame-gizmo to bring the lug yard out from the mast is something I have often fantasized about. I have imagined a high-tech-material triangulated frame on both throat and tack to get either a lug or a balanced lug away from the mast while letting the sail rotate around the mast freely (I also envisioned the tack being able to slide a good distance either side of the mast on a kind of traveler rod, but once you sketch it and run thought-experiments, that doesn't sound good). Both frames would have to endure halyard and downhaul tensions (and so I imagine them as seriously triangulated structures, though if the trinaguated support were in tension, that would keep weight down) , but who's to say a strong frame light enough to suit isn't possible for this? However, when I mentioned this idea to my other forum, that was when the German researcher informed me that standing lug mast interference wasn't as a big a deal as I thought. -- Wade

[mick allen]

so most people would say that Roman and post-Roman influence flowed up to inspire the North

Ceasar's annihilation of the more capable (his comment) Veneti ships at the battle of Morbiham Gulf (North Atlantic) used the tactic of snagging their sail (lateen?) rigging in 56 BC.

[obscured by clouds]

it was truly amazing to sail and an awfully good learning platform. It's no wonder that so many of the America's Cup skippers and mainsheet trimmers spent a good deal of time in the Star class. It's like a masters class in sail shaping. ...and also explains the outcry when ISAF wanted to replace the Star as the Olympic keelboat. The various supporters cited the Star as being the 'ultimate sailor's boat' because of the difficulty aspect [masts break a lot!]. For something which is a bit of an anachronism to still be an olympic class is testament in itself.

Anyway back to the subject.

Surprise's lug is essentially a SL but with a stiff full length batten at the bottom:

http://premium1.uploadit.org/swordie//tv1.jpg

The idea is to for the batten to be flexible enough to allow a decent shape to be attained on the wind, and yet stiff enough to stop the sail collapsing when running free. The amount of material in the foot area under the bottom batten makes the sail self vanging [supposedly]. The above photo is'nt the best as the haliard should be attached to the yard further back at around 35% rather than the 25% you see here. Spars are carbon.

Apparently Nigel Irens [Romilly] put a fair amount of input into the design aspects of the rig.

I've had no other feedback from the owner as to whether it does work as intended, but it seems a practical way of trying to obtain the best from the two systems.

[gert]

Todd:
Do you have a detail of the downhaul here?
http://farm3.static.flickr.com/2590/3916023230_77b95dda09_m.jpg
I tried to figure one out yesterday using a side jaw, but the
mast partner interferes also as the boom swings, the down haul
tension changes. Or is the dh constantly being adjusted?

[Todd Bradshaw]

How is the partner interfering with your boom jaw? I'm not sure I'm getting your drift..... I never got much farther than a concept drawing on that one, so the fine points of the rig are still to be determined. I would probably just use a simple downhaul lashing and a parrel on the boom at the mast intersection (but a jaw would probably also work). There is enough boom/yard/battens and sail weight aft of the mast that I doubt a more sophisticated downhaul would be needed for kepping that short luff reasonably firm. Depending on where the downhaul was lashed to the boom and its angle of pull, the configuration might tend to change or tilt slightly with different trim angles, but it's probably not going to have a huge effect on performance if things wander a little bit in use. I've always really liked that sail's profile shape and someday, I'm going to use it on something. I was fooling around with a design for a solo outrigger canoe and this is just one of the rigs I pasted onto it to see how it would look.

This, by the way, was the original rig I drew for the hull. I was looking for something simple, with good visibility under the sails and which would quickly stow in a couple long, skinny bindles that could be lashed to the beams.

http://webpages.charter.net/tbradshaw/!SOLOBOP-copy.jpg

It will have to wait though, because If I ever get the time, money, space and energy all at once, the front runner for building an outrigger would be to strip up one of Gary Dierking's Uluas. I have a pile of scrap Dacron cut-offs that I'm saving for building the sail. The endless search for new toys in the Universe.....I'd better get off my butt and start building something other than just sails for other people one of these days. Otherwise, I might eventually die with just all the boats that I already own, which is always a sad situation....

http://webpages.charter.net/tbradshaw/ulua.jpg

[wtarzia]

Do you think that, if the crabclaw sails were loose-footed, the aerodynamics would be better? Gary seems to think so when he uses the oceanic sprit (though his latest adventure put a western sprit sail on his 20 foot single outrigger, which he has been sailing at Fiji during vacation -- he brought a few tools and the sail, and built the boat on the beach in two weeks with local materials). My crabclaw had the boom a little lower, but yes it did give good visiblity, and brailed up fast (I used two spiller lines, one on either side of sail, and hauling both provided brailing) -- a fine stowable sail, rapidly deployable and take-downable, and tidy when stored, as you say. -- Wade

[Lewisboats]

Am putting a BL on my current build and I have a question about the mast head. I bought a nice Sheave but it seems that most are just a hole in the mast. Should I bother to put the sheave in the mast or just bore a hole and bevel it?

[JimD]

Am putting a BL on my current build and I have a question about the mast head. I bought a nice Sheave but it seems that most are just a hole in the mast. Should I bother to put the sheave in the mast or just bore a hole and bevel it?

Depends on how fast you want to wear out the halyard.

[Todd Bradshaw]

Unless it's a really big sail, I don't think I'd bother with the sheave, although it could certainly be done if you're willing to do the extra work involved. For a sheave-less version (dumb-sheave) it's possible to ease the lower corners of the hole so that you're making a ramp for the halyard to go up, through the masthead and down again with less friction than a straight hole bored through it would present. I have seen people line the bottom bearing surface of these "up-and-over-style" slots with a strip of metal to reduce chafe and friction.

It can also be done by cutting a small vertical slot in the mast (bore two holes through it, maybe 1"-1.5" apart, with one directly above the other and then neatly remove the wood between them). Then you build and insert a pre-manufactured ramp in the slot. It could be glued in or held in with some sort of cross-pin. Here is the original phenolic ramp piece from my old Starboat's mast. I replaced it with a similar one that I carved from a block of leftover epoxy resin with a hefty dash of graphite powder added for low-friction. This one was for a wire halyard. A ramp for a rope halyard would wider, but look similar.

http://webpages.charter.net/tbradshaw/dumbsheave-001.jpg

Wade, about the only thing I know about claw rigs is that I want to try one some day, so I can't speculate much on the loose-foot vs. laced foot question. As with any loose-footed sail though, it would probably yield a bit more draft adjustment along that edge. Whether this would make much difference in performance, I don't know - and the advantages of an adjustable foot also depend to a great extent on whether or not the sailors actually adjust it when sailing. An awful lot of people tend to set it, forget it and just sail (myself included on some occasions).

[Lewisboats]

How-bout making one of those out of high density (white cuttingboard stuff) plastic. it is self lubricating and I can get my hands on however much I want of it. The sail is 75 sq ft going on a 12 ft scow (read transom bowed) hull. I might want to use the mast and sail on a 12 ft skiff my son and I are going to build for him too...or one very similar.

[Todd Bradshaw]

I think that stuff would probably work fine. If it's UHMW polyethylene (most are) it may be somewhat tricky to glue to (rough it up on the glueing surface and then quickly pass the blue part of a torch flame over it, apply epoxy to wood and dumbsheave and stick in in place) but you could always seal the wood well and then pin the sheave in place with some sort of cross-pin....or both.

[Lewisboats]

Thnx...I think I'll put 2 small (1/8") pins about 1/2" apart...that ought to secure it enough. I work in a meat packing plant and all of the boards that are there are of this stuff. We have 3 kinds...soft, hard and shatter concrete hard. The soft ones can be planed and reused...the others are pretty much throw away after use...but they last twice as long or more...works out to about the same I guess money wise. I can get as much trimmings and scrap as I need.

[Jigsaw]

I set a loose footed balanced lug with a topsail. It looks a bit complicated but splitting up a large lug is, I think, the best way of controlling the power a lug produces. It also gives a wide range of different sail options. Although Jigsaw is only 13 foot, I think the rig would work well on a larger boat.

[gert]

http://farm4.static.flickr.com/3457/3947878701_3bf2ec6014.jpg
jigsaw