Page 4 of 4 FirstFirst ... 34
Results 106 to 133 of 133

Thread: efficiency of the sprit rig

  1. #106
    Join Date
    Nov 2001
    Location
    Seattle
    Posts
    22,210

    Default Re: efficiency of the sprit rig

    Adept with sprit rig 11-16-2017 11-48-06 AM 649x837.bmp.jpg

    So, more like this? I didn't raise the tack very much. Don't want to lose a lot of sail area. What is your opinion on battens? I wouldn't mind having a bit of roach.

  2. #107
    Join Date
    Jan 2010
    Location
    Sweden,Scilly Isles, Siberia
    Posts
    7,938

    Default Re: efficiency of the sprit rig



    Yeah, it works ok. Reefing is awkward. Boat was much better with a balanced lug. I would think about a standing lug if you want a trad sail without boom-on-the-head-issues.

  3. #108
    Join Date
    Nov 2001
    Location
    Seattle
    Posts
    22,210

    Default Re: efficiency of the sprit rig

    I have considered a balanced lug. The sprit rig was much more common on American workboats, which is why I have a bias toward it.

  4. #109
    Join Date
    Jun 2000
    Location
    Madison Wisconsin
    Posts
    8,541

    Default Re: efficiency of the sprit rig

    Yep, that's better. If I'm going to bother with a roach and battens on a sail, it's going to be a very substantial roach that actually might do something. Otherwise, it's generally little more than an additional cause of leech flap and tedious, expensive sail repairs down the road. A small roach may yield a small speed gain at a few specific times, though a five second lapse in concentration by the skipper, or a brief sail trimming error is often enough to wipe out any gains you made on that tack with most go-fast additions. For recreational, non-class-race sailing most stuff where you have to watch the knot meter to see any evidence of a speed gain probably isn't worth doing unless it's yielding some other big bonus - easier sail handling, etc.

    If it was a traditional, vertically-cut spritsail it would never have either a roach or battens.

  5. #110
    Join Date
    Nov 2001
    Location
    Seattle
    Posts
    22,210

    Default Re: efficiency of the sprit rig

    Quote Originally Posted by Todd Bradshaw View Post
    Yep, that's better. If I'm going to bother with a roach and battens on a sail, it's going to be a very substantial roach that actually might do something. Otherwise, it's generally little more than an additional cause of leech flap and tedious, expensive sail repairs down the road. A small roach may yield a small speed gain at a few specific times, though a five second lapse in concentration by the skipper, or a brief sail trimming error is often enough to wipe out any gains you made on that tack with most go-fast additions. For recreational, non-class-race sailing most stuff where you have to watch the knot meter to see any evidence of a speed gain probably isn't worth doing unless it's yielding some other big bonus - easier sail handling, etc.

    If it was a traditional, vertically-cut spritsail it would never have either a roach or battens.
    Thanks!

  6. #111
    Join Date
    Jan 2000
    Location
    Cushing, Maine
    Posts
    3,118

    Default Re: efficiency of the sprit rig

    I like lowering the tack and raising the clew as done in the Delaware boats. The boom on my boomed sprit sail rigs clears my head easily at the cost of only a little area. The Delaware folks also set up to brail their boomed sails with a line that runs from the throat down to a bee hole under the boom and back up to a ring or little block then down. Pull on it and the whole rig folds against the mast. Details on this and other sprit taming devices are in pieces I did for WB and SBM.
    Ben Fuller
    Ran Tan, Liten Kuhling, Tipsy, Tippy, Josef W., Merry Mouth, Imp, Macavity, Look Far, Flash and a quiver of other 'yaks.
    "Bound fast is boatless man."

  7. #112
    Join Date
    Nov 2001
    Location
    Seattle
    Posts
    22,210

    Default Re: efficiency of the sprit rig

    Quote Originally Posted by Ben Fuller View Post
    I like lowering the tack and raising the clew as done in the Delaware boats. The boom on my boomed sprit sail rigs clears my head easily at the cost of only a little area. The Delaware folks also set up to brail their boomed sails with a line that runs from the throat down to a bee hole under the boom and back up to a ring or little block then down. Pull on it and the whole rig folds against the mast. Details on this and other sprit taming devices are in pieces I did for WB and SBM.
    I was thinking about something like that. Is there a link the could get me to the articles? I no longer own a complete run of WoodenBoat magazine.

  8. #113
    Join Date
    Sep 2002
    Location
    Hamilton New Zealand
    Posts
    3,968

    Default Re: efficiency of the sprit rig

    Quote Originally Posted by johnw View Post
    I have considered a balanced lug. The sprit rig was much more common on American workboats, which is why I have a bias toward it.
    A lot of the small traditional inshore fishing boats that we tend to use as examples had little lateral plane ( keels or centerboards) so weren't going to go to windward very well, oar assist was very commonly used.
    Our expectations these days are for much better performance, so we have better foils and much more stable sailcloth.

    John Welsford, who has tried a considerable number of different sail configurations and who likes the balanced lug a lot.
    An expert is but a beginner with experience.

  9. #114
    Join Date
    Jan 2000
    Location
    Cushing, Maine
    Posts
    3,118

    Default Re: efficiency of the sprit rig

    Quote Originally Posted by johnw View Post
    I was thinking about something like that. Is there a link the could get me to the articles? I no longer own a complete run of WoodenBoat magazine.
    I think WB has an index and for a few bucks send along an electronic issue. You'll need to check the online index. I also did a piece last year I think for Chris Cunningham at Small Boat Monthly.

    Looking at Todd's comments about raising the sail if the tack angle is less than 90 degrees, I'd never thought about that as my boomed sprits get put away by brailing everything then pulling the whole rig out. But the largest is only 75 feet or so. Bigger ones as found on larger workboats do want halyards, but are rarely boomed. If I was doing a larger boomed rig I'd do what I did with my gaff rigged ice boat. I'd done forth and back lacing but it was a little challenging to do it on a 20 degree day. So I went with the Dutch traditional system where they use robands and toggles, still following the forth and back pattern. Fast and easy.
    Ben Fuller
    Ran Tan, Liten Kuhling, Tipsy, Tippy, Josef W., Merry Mouth, Imp, Macavity, Look Far, Flash and a quiver of other 'yaks.
    "Bound fast is boatless man."

  10. #115
    Join Date
    Jan 2009
    Location
    northwestern Wisconsin
    Posts
    2,778

    Default Re: efficiency of the sprit rig

    Quote Originally Posted by john welsford View Post
    Our expectations these days are for much better performance, so we have better foils and much more stable sailcloth.
    John,

    seems to me this might be more the other way around.

    What are your thoughts on the standing lug vs. the balance lug? I'd love to hear what you think, having moved to a standing lug on my new boat. (Which of course would be substantial thread drift in a discussion of spritsails...)

    Tom
    You don't have to be prepared as long as you're willing to suffer the consequences.

    www.tompamperin.com

  11. #116
    Join Date
    Jan 2009
    Location
    Narragansett Bay and Approaches
    Posts
    119

    Default Re: efficiency of the sprit rig

    kids boat.jpg
    So what if you hooked the sprit to the boom?
    It would maintain leech tension, which goes a long way toward controlling twist.
    It could be a jaw or slider that allows you to vary tension by how far aft you pull it.
    I just stuck it on a cartoon I did for a Kids Boat that was basically a Optimist with sheer cut down and a simple deck and cockpit instead.
    Probably something Grandpa could whip up in a weekend.
    SHC

  12. #117
    Join Date
    Nov 2001
    Location
    Seattle
    Posts
    22,210

    Default Re: efficiency of the sprit rig

    Quote Originally Posted by SHClark View Post
    kids boat.jpg
    So what if you hooked the sprit to the boom?
    It would maintain leech tension, which goes a long way toward controlling twist.
    It could be a jaw or slider that allows you to vary tension by how far aft you pull it.
    I just stuck it on a cartoon I did for a Kids Boat that was basically a Optimist with sheer cut down and a simple deck and cockpit instead.
    Probably something Grandpa could whip up in a weekend.
    SHC
    Now, that's interesting. I suppose the downside is that the sprit would ruin more of the sail on the 'wrong' tack. Racing sneakboxes evolved to spoil as little of the sail as possible:



    On the other hand, they always put the sprit on the mast. You've got some serious lateral thinking there. With a loose-footed sail, you could even use a collar on the boom. Maybe we could get some opinions on whether twist is a big enough problem that it needs a radical solution.

  13. #118
    Join Date
    Jun 2000
    Location
    Madison Wisconsin
    Posts
    8,541

    Default Re: efficiency of the sprit rig

    First you probably need to figure out if and when twist is a problem. For example, in Tom's standing vs. balanced lug comparison. One of the strong points of a standing lug over a balanced lug is that you can induce twist into the standing lug as a depowering aid when needed. On the other hand, one of the strong points of the balanced lug is that its configuration naturally resists twist, helping to keep the entire sail working for you. Neither is the "correct", only, or best way to do it and both systems have certain merits.

    This discussion seems to be overly focused on twist as a bad thing, which is a mistake. It's also going pretty far overboard on the "bad tack" thing, which very often doesn't seem to make enough difference to worry about. Are you telling me that you're such good helmsmen and such good sail trimmers that it's the theoretical bad tack that's going to cost you noticeable VMG? A little goof here and there at the tiller, or a bit of bad trimming, or just a bad decision is likely to have far more noticeable consequences.

  14. #119
    Join Date
    Dec 2011
    Location
    North East England
    Posts
    677

    Default Re: efficiency of the sprit rig

    Quote Originally Posted by SHClark View Post
    kids boat.jpg
    So what if you hooked the sprit to the boom?
    It would maintain leech tension, which goes a long way toward controlling twist.
    It could be a jaw or slider that allows you to vary tension by how far aft you pull it.
    I just stuck it on a cartoon I did for a Kids Boat that was basically a Optimist with sheer cut down and a simple deck and cockpit instead.
    Probably something Grandpa could whip up in a weekend.
    SHC
    11 out of 10 for originality, that is certainly a new one. I am pretty sure though that the 4th corner would sag off, badly. I would love to see you prove me wrong though.

  15. #120
    Join Date
    Nov 2001
    Location
    Seattle
    Posts
    22,210

    Default Re: efficiency of the sprit rig

    Quote Originally Posted by Todd Bradshaw View Post
    First you probably need to figure out if and when twist is a problem. For example, in Tom's standing vs. balanced lug comparison. One of the strong points of a standing lug over a balanced lug is that you can induce twist into the standing lug as a depowering aid when needed. On the other hand, one of the strong points of the balanced lug is that its configuration naturally resists twist, helping to keep the entire sail working for you. Neither is the "correct", only, or best way to do it and both systems have certain merits.

    This discussion seems to be overly focused on twist as a bad thing, which is a mistake. It's also going pretty far overboard on the "bad tack" thing, which very often doesn't seem to make enough difference to worry about. Are you telling me that you're such good helmsmen and such good sail trimmers that it's the theoretical bad tack that's going to cost you noticeable VMG? A little goof here and there at the tiller, or a bit of bad trimming, or just a bad decision is likely to have far more noticeable consequences.
    I suspect Steve is that good a helmsman. I agree that it's more important to have a practical rig than one that has the ultimate performance. But what if you could have a practical rig with better performance? After all, people were sailing for thousands of years before someone said, why not put a triangular sail on that stay? Jibs didn't appear until around 1600, and they've proven pretty handy. It's still possible to invent new things.

  16. #121
    Join Date
    Jan 2009
    Location
    northwestern Wisconsin
    Posts
    2,778

    Default Re: efficiency of the sprit rig

    Quote Originally Posted by Todd Bradshaw View Post
    First you probably need to figure out if and when twist is a problem. For example, in Tom's standing vs. balanced lug comparison. One of the strong points of a standing lug over a balanced lug is that you can induce twist into the standing lug as a depowering aid when needed. On the other hand, one of the strong points of the balanced lug is that its configuration naturally resists twist, helping to keep the entire sail working for you. Neither is the "correct", only, or best way to do it and both systems have certain merits.
    Todd,

    thanks for sharing your thoughts about lug rigs--that's a very succinct comparison. Is there any reason to use one approach to twist over the other?

    In other words, a standing lug will twist, automatically depowering the sail.

    A balance lug will resist twisting, which would keep a greater percentage of its sail area working for you--and thus perhaps making it more necessary to reef a balance lug than a standing lug, given the same sail area.

    In what situation might one be better than the other? Is this just a personal preference? Thanks for any insights you can share--I'm curious.

    Tom
    You don't have to be prepared as long as you're willing to suffer the consequences.

    www.tompamperin.com

  17. #122
    Join Date
    Sep 2002
    Location
    Hamilton New Zealand
    Posts
    3,968

    Default Re: efficiency of the sprit rig

    Quote Originally Posted by WI-Tom View Post
    Todd,

    thanks for sharing your thoughts about lug rigs--that's a very succinct comparison. Is there any reason to use one approach to twist over the other?

    In other words, a standing lug will twist, automatically depowering the sail.

    A balance lug will resist twisting, which would keep a greater percentage of its sail area working for you--and thus perhaps making it more necessary to reef a balance lug than a standing lug, given the same sail area.

    In what situation might one be better than the other? Is this just a personal preference? Thanks for any insights you can share--I'm curious.

    Tom
    If the yard on the balanced lug is properly tuned to the sail and the boat, it will flex in higher winds allowing the upper leach of the sail to fall off , depowering the rig.

    John Welsford
    An expert is but a beginner with experience.

  18. #123
    Join Date
    Sep 2002
    Location
    Hamilton New Zealand
    Posts
    3,968

    Default Re: efficiency of the sprit rig

    Quote Originally Posted by WI-Tom View Post
    John,

    seems to me this might be more the other way around.

    What are your thoughts on the standing lug vs. the balance lug? I'd love to hear what you think, having moved to a standing lug on my new boat. (Which of course would be substantial thread drift in a discussion of spritsails...)

    Tom
    I've used both, with sprits, and sprit booms on various rigs of similar four sided shape. I've ended up with a strong preference for the balanced lug. They are easier to tune for shape and twist, softer to gybe, have less sheet tension, and I suspect, although that might be that I've just been working on the issue for longer, are closer winded.

    One of the issues with any of these sails is finding a sailmaker who actually understands the sail and how to shape it, many of those who use computer software to cut the panels dont seem to get it right. I'm working with a gent at present who is a very competent sail maker but who's never made one of these, but he's interested enough to alter the programming of his cutting system to produce what I want. I'm having a sail made and will report on it.

    John Welsford
    An expert is but a beginner with experience.

  19. #124
    Join Date
    Jan 2005
    Location
    Deepest Darkest Wales
    Posts
    18,440

    Default Re: efficiency of the sprit rig

    Is there any major difference in principle between a battened balanced lug and a junk, other than the sheeting scheme.
    Someday, I'm going to settle down and be a grumpy old man.

  20. #125
    Join Date
    Sep 2002
    Location
    Hamilton New Zealand
    Posts
    3,968

    Default Re: efficiency of the sprit rig

    Quote Originally Posted by P.I. Stazzer-Newt View Post
    Is there any major difference in principle between a battened balanced lug and a junk, other than the sheeting scheme.
    A whole lot of rope and string. I love the junk rig in its place, but think that the crossover from a balanced lugsail to the junk rig with its sail management system that gives such easy reefing and handling is around 150 sq ft or so in area. They're really well suited to single or shorthanded cruising where ease of sail management is paramount.
    All that extra ropework though is weight aloft and windage, cost and complication but I'd have to admit that once set up its very nice to sail with.
    I dont think that its suited to boats which have to be rigged and un each time they go sailing.
    I've tried a fully battened balanced lug, have mixed feelings about it, it certainly performed very well but I"m not sure it was worth the extra cost and complication.
    Perhaps on a very roachy sail, maybe, perhaps.

    John Welsford
    An expert is but a beginner with experience.

  21. #126
    Join Date
    Nov 2001
    Location
    Seattle
    Posts
    22,210

    Default Re: efficiency of the sprit rig

    The balanced lug keeps coming up, so I've drawn the boat with that rig as well. I tried to draw it so that the CE won't shift too much as you reef it. Please tell me what I've done wrong, and what the tradeoffs are for different shapes of balanced lug.

    adept skiff with lug rig 11-17-2017 2-56-55 PM 736x841.bmp.jpg

  22. #127
    Join Date
    Sep 2002
    Location
    Hamilton New Zealand
    Posts
    3,968

    Default Re: efficiency of the sprit rig

    Quote Originally Posted by johnw View Post
    The balanced lug keeps coming up, so I've drawn the boat with that rig as well. I tried to draw it so that the CE won't shift too much as you reef it. Please tell me what I've done wrong, and what the tradeoffs are for different shapes of balanced lug.

    adept skiff with lug rig 11-17-2017 2-56-55 PM 736x841.bmp.jpg
    Looks fine to me, but do put a little hollow in the leach. Maybe 75mm or so. Todd?

    John Welsford
    An expert is but a beginner with experience.

  23. #128
    Join Date
    Jun 2000
    Location
    Madison Wisconsin
    Posts
    8,541

    Default Re: efficiency of the sprit rig

    An inch or so of hollow for every 6' of leech length works pretty well at preventing flutter as the sail ages. The perimeter shape looks good to me as long as it puts the CE where it needs to be. The luff would be cut dead straight or slightly hollowed, leech hollowed and the head and foot edges would have some round added. Most balanced lugs reef pretty much straight up and down, or pretty close to it. The fore and aft location of the CE doesn't move much as you reef. Standing lugs are the ones where the peak angle, boom angle and fore and aft CE location need to be checked carefully when planning reefs. The first reef will usually be fine, but when you start putting deeper reefs in and you're pulling parts higher up the luff back to be the new reef tack corners that things get strange. If you want to reef without having to re-tie the halyard to a different spot on the yard you may need to get creative with the orientation of the upper reef lines and plan (draw out) the reefed plans to see what's happening to your centers.

  24. #129
    Join Date
    Sep 2002
    Location
    Hamilton New Zealand
    Posts
    3,968

    Default Re: efficiency of the sprit rig

    I find that as the wind increases, the boat generally gets a bit heavier on the helm, so the centre of effort moving forward very slightly as the sail is reefed can counter that to a certain degree. I do position the reef lines so that the after end is taking a little more out than at the luff, the idea being that in heavy conditions the boat may be rolling around more, and cocking the after end of the boom up slightly keeps it clear of the water, and the crews heads as well.

    John Welsford
    An expert is but a beginner with experience.

  25. #130
    Join Date
    Nov 2001
    Location
    Seattle
    Posts
    22,210

    Default Re: efficiency of the sprit rig

    Thank you both for your insights.

    One more rig I'd like to consider for this project is the gaff rig. I'm quite familiar with the rig, so I have fewer questions about it. Some of you may know that I'm active in the Center for Wooden Boats, and the emphasis there has gone more to Northwest boats. There used to be something called the Kitten class, first introduced to the Royal Vancouver Yacht Club in the 1920s, a rather narrow catboat designed by John Winslow. CWB has one in storage, and I'm thinking if we could have a sort of 'spirit of tradition' version of the Kitten in the fleet that is big enough for an instructor and two students, it might encourage more interest in traditional rigs. I started with the sprit rig, in part because it gives you the most sail area for mast height, reducing the weight in the bow. But if this project gets off the ground, it will be because I've convinced some other people it's a good idea, and I want to be ready with options and answers. Here's the gaff rig I've drawn:

    15' Adept skiff with gaff rig 11-18-2017 2-15-56 PM 766x818.bmp.jpg

    I think it looks okay, or at least looks like the Kitten rig, but you folks have been so helpful about things I wouldn't have thought of, I'd like your comments on it.

  26. #131
    Join Date
    Jun 2000
    Location
    Madison Wisconsin
    Posts
    8,541

    Default Re: efficiency of the sprit rig

    I think the profiles and proportions of both the gaff and balanced lugsail look quite good and seem to visually fit quite well. My gut suggests that the spars on the gaffer might need to be a bit more stout, but that and any other issues could be worked out as the plan develops and you get down into the serious, nuts and bolts design stuff - helm balance, righting moments, etc.

  27. #132
    Join Date
    Jan 2000
    Location
    Cushing, Maine
    Posts
    3,118

    Default Re: efficiency of the sprit rig

    Looks to me that you are up around the 100 sq ft area in the gaffer. That's about the sail area in a beetle cat rig which would be a place to start for spar dimensions. You will likely need a head stay to help deal with the bending of the mast head because of the peak halyard. If the sail needs to come off, and you are using hoops you'll need the beetle style quick release fittings or togged forth and back lacing.
    Ben Fuller
    Ran Tan, Liten Kuhling, Tipsy, Tippy, Josef W., Merry Mouth, Imp, Macavity, Look Far, Flash and a quiver of other 'yaks.
    "Bound fast is boatless man."

  28. #133
    Join Date
    Nov 2001
    Location
    Seattle
    Posts
    22,210

    Default Re: efficiency of the sprit rig

    Closer to 140 sq. ft., which might be excessive.

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •