Sprit boomed leg o mutton

[Dan St Gean]

I'm building a strip built Hawaiian outrigger that will sport a freestanding rig of 128'. The luff length will be 19'3", and the foot will be 11'. I am building a two piece mast with the bottom being aluminum and the top section being a tapered birdsmouth section. A few questions regarding the building and rigging of the mast and sprit.

1. Should I epoxy the two sections together or do you think that they could be two piece that sleeve together?
2. How should I rig the halyard on a freestanding rig? Should I rig a sheave or a dumb sheave? What size line should I use for the halyard with a 128'. Should I cleat it to the mast so it will be free to revolve?
3. How should I rig the sprit? I am using 5/8" Schaefer sail track for the main. Traditionally the snotter would be lashet to the mast and tension the sail. Should I make the height of the snotter adjustable? Does anyone have a good diagram or description?

[DougWilde]

Dan,

I assume you mean 128 sq ft sail area.
What I am about to say is based on my (limited) experience with a Windward 15 whose mast is 19'9" and has a sprit boom. And I also lived in Hawai'i for eight years, mostly on the Big Island.

How long is your mast? Even in two parts you'll have to raise and step it as one. So why not build it as one piece unless transporting it becomes a problem. How long is your hull? Two parts makes it that much more complicated.
The mast for Williwaw is solid Sitka and not that difficult to raise and step. Your's would be minimaly longer and likely lighter.

The designer called for a dumb sheave but I put a real one on a 1/2" bronze rod. That pretty much is dealer's choice and either would work. The halyard is 1/4" and cleats to the mast. Actually I have two cleats on opposite sides of the mast, secured with dowels instead of screws. One is for the halyard and the other for the downhaul.

I'd lose the sailtrack. How are you going to do that with a two part mast? Lacing would be more in keeping with an outrigger canoe. Some folks install a thumb cleat on the mast to hold the snotter in place (take a look in Capt'n Pete's book). But then you are limited to always rigging the mast one way. I loop mine through one of the grommets on the luff of the sail. The downward pressure is not great and does not distort the sail. This lets me adjust where I position the snotter on the mast. The fall can either go down to a cleat or back to the sprit.

Doug Wilde

[Dennis Marshall]

Doug, do you have any pics of the Windward 15? How about a report of its sailing abilities? I'd appreciate any info as I've admired that particular boat for some time.

Dennis

[Dan St Gean]

I am no purist in this matter. I'm going with sail track and slides to make refing easy. As for the one or two piece mast, I'm leaning towards your suggestion of a single piece. The only reason I'm thinking of making it seperate is to stow it in the cockpit. The boat is 21' long and will be sailed as a tri. The outriggers have just been glassed and the sail track came in this weekend. Time to build the rest of the mast.

[Keith Wilson]

My experience with this rig involves somewhat smaller sails, but I’ll put in my two cents. My prejudice is for modern blocks and line, even with a traditional rig – ball bearing blocks and low-stretch line that’s easy on the hands are wonderful things. If you want to be really traditional, ignore all this.

Sail shape is adjusted with luff tension, snotter tension (this is equivalent to clew outhaul tension on a standard modern sail), and snotter position. If it were my boat, I’d use a single-part halyard with a sheave or a block hung from a doodad (can’t remember the proper name for the little extension thing at the masthead) on the back of the mast, with whatever size line was comfortable on the hands and didn’t stretch too much with ordinary rope, 3/8” or maybe 5/16”. I’d also rig a four-part tack downhaul so that I could get plenty of luff tension without having to pull really hard on the halyard, and adjust it easily while underway. ¼” rope and itty-bitty Harken blocks would be good here, with a snapshackle so reefing is quicker. Cleating to the mast will allow it to rotate, which would be good, but if it would be a lot more convenient to have the lines led somewhere else, that probably takes precedence.

I have found that adjustments to the snotter position on the mast don’t seem to matter much if it’s more or less in the right place, so I run the snotter from the end of the sprit, through a block bolted to the mast, and down to a cleat at a convenient location. With a sail this size, a two-part tackle on the snotter would probably be a good thing - I’d use a block with a becket bolted to the mast and a single block on the snotter end. If you wanted to be able to adjust the snotter position, the block on the mast could be rigged like a jib sheet, with the block on a short piece of track attached to the mast. Using sail track makes reefing a lot easier, because there’s no interference between lacing or mast hoops and the snotter.

I think I’d want a topping lift, particularly for reefing. It makes things a lot easier. Depending on how high the boom is, you could cleat on the boom, but it’s usually easier to have a masthead block and run it down to a cleat near the foot of the mast.

I'd make the mast all out of wood in one piece. It's not that long. Birdsmouth spars can be quite light, and a joint is always problematic. You'd also have to make sure the sail track lines up pretty well or it will give trouble.

Anyway, that’s how I’d do it if it were my boat.

[ 11-09-2004, 11:32 AM: Message edited by: Keith Wilson ]

[Dan St Gean]

Keith,

Thanks for the detailed reply. I was a little frightened of the loads imposed on the mast by the freestanding section, but If I had to do it again I would most definately do the whole mast that way. However, I have a big, expensive piece of 6061 T6 that is going to get used on this boat. I do think that the sail track will need aligning either way since it comes in 12' sections. I plan on gathering a few opinions and then making up my own mind regarding the one or two piece mast. Stowing it in the canoe seems like a seamanlike approach, but striking a 22'6' freestanding mast in a seaway doesn't sound like fun at all anyhow--one piece or two. I anticipate rigging the boat either to sail as a tri or to paddle with one outrigger and not changing while out there. Thanks for the information regarding the rigging. I'll be picking up the mast track this afternoon, and hopefuly will get the mast assembled this week! Since I'm heading up to West Marine anyhow this afternoon, I may see what they have in stock in regards to the sheave and downhaul blocks.

Sincerely,

Dan St. Gean

[Dan St Gean]

Well I picked up the mast track last night and had a look at the blocks and such at WM. They're kind of pricy! However, it makes a difference ing the smoothness of the operation to use them. To rig the leg o mutton I'm thinking I need:

1. Rope halyard with eye
2. Halyard shackle
3. Downhaul with 3 or 4 to 1 and th blocks to handle that (1/4" line max)
4. Snotter attachment hardware. I'm investigating a sliding block that would allow attachment height variation or perhaps a pair of cheek blocks to do the same. Any idea how much snotter tension there will be with 128 square feet of sail and an 11' foot? How many part tackle should I use there?
5. Main sheet--how many part main should I use?

[Keith Wilson]

Ah, yes, the other major disadvantage of modern hardware: it's not at all cheap.

A single-part snotter tackle works fine with 60 sq ft of sail - flattens the sail and bends the mast nicely without too much line tension, so I'm guessing that two parts would be fine.

Sprit booms, because they're self-vanging (the sail holds the end of the boom down) need less sheet force than a "normal" sail. A single-part sheet is fine for 60 sq. feet with a cam cleat, so maybe two parts with 3/8" line? I think that's what I'd start with. 3/8 is a lot stronger than you need, but anything smaller is awfully hard on your hands. I personally like Dacron 3-strand, because I can make the splices myself.

For larger blocks, Garhauer (http://garhauermarine.com/) make quite nice ones that are generally quite a bit cheaper than Harken. They don’t sell them in retail stores; you have to buy from them directly. I don't know if you need anything that large, though - might be good for the mainsheet.

[DougWilde]

Why all the hardware? Two part tackle on the snotter? Put enough tension on that puppy and it gets away from you and your sprit becomes an arrow fired across the anchorage by your mast. And a four part downhaul? On a two piece mast? Snap city.

Striking the mast is an iffy proposition when afloat, although they must have done it with such boats as the Chincoteauge skiff. And you'll have to strike it as one piece, even if it is made up as two. That means some sort of pin or other means to keep the two parts together while she is lowered from vertical to horizontal.

KISS
Try it first without the hardware. Other than the sheave for the halyard, no mechanical assistance is needed with Williwaw's 70 sq ft of sail.

As far as reefing this sort of rig, how is your sail cut? Reefing along the luff or foot? Rig the outhaul and snotter so they remain attached to the sprit. I built according to plan and that was not what was suggested. First time I struck sail in a breeze the outhaul went over the side.

Pictures are still in the camera.

I have a couple other photos and drawings I'll have to scan for this discussion.

Norm also has a Windward 15 and should have some photos of his rig.

Doug

[DougWilde]

From "Pete Culler's Boats: The Complete Design Catalog" by John Burke (ISBN 0-87742-142-0), one way to rig a snotter.

http://dbwilde.home.comcast.net/BoatScans/Snotter1.jpg

All sorts of variations are possible on this. A point to note is how one tug on the line releases the snotter. Very nice.

I like the forked end of the sprit. On the Chincoteague skiff at the Chesapeake Bay Maritime Museum the snotter goes from the end of the sprit, to the mast, back down through the fork, then back along the side of the sprit and is tied off on a small cleat on the sprit.

Doug

[Keith Wilson]

A brief defense of "all that hardware": I've personally used this on two boats with 60 sq ft. sails with sprit booms, and have been very pleased. I've also had the same rig with the low-tech KISS arrangement, and switched it over to the more complex one because you get much better control of the sail shape with less effort. One of the great advantages of the sprit boom rig is that it's easy to have very good control of sail shape without a lot of complex hardware; no outhaul, no cunningham, no flattening reef, no mainsheet traveler, no boom vang, no backstay adjuster, none of that. Snotter tension (controlling mast bend) and luff tension do it all.

A multiple-part tackle with low-friction ball-bearing blocks allows you to get a fair amount of force without pulling too hard. Why work harder than you have to? It also allows releasing instantly because of low friction. You are by no means required to pull hard enough to launch your sprit like an arrow into the harbor, much less break your mast! No it's not essential, but the boat will sail better with less effort. The only disadvantage is the cost, which is minimal compared to a standard modern rig.

You can't reef a sail on the foot with Pete Culler's snotter - the part around the mast gets in the way of robands, lacing, mast hoops, or sail slides on a track. I'll also point out that it's a 3-part tackle, which seems unnecessary except for that very high-friction deadeye. In addition, the snotter is belayed on the end of the sprit, which is scarcely the most convenient place; when you want to release the snotter, the sprit is usually flogging around. Pete Culler designed some very nice boats, but he was IMHO besotted with tradition, and thought that anything that hadn't been used for at least 300 years was a useless new-fangled innovation. He advocated tarred manila rope in the ‘80s, for God’s sake! I’m also something of a traditionalist, but modern low-stretch line, Dacron sailcloth, and low-friction blocks are VAST improvements over what preceded them.

Actually, I like the forked ends of the sprit too. I tie the mainsheet to the clew grommet with a bowline, then tie a stopper knot about 2" away. The mainsheet then just runs through the slot in the end of the sprit; no need for a separate outhaul. I have a similar arrangement with the snotter – a stopper knot on the end hooks in the slot, then the snotter runs through a small Harken block fastened to the mast, and down to a cleat in a convenient location. This won’t work with the larger sail without modifications, since you’ll need more force than a single-part sheet allows.

[ 11-11-2004, 10:15 AM: Message edited by: Keith Wilson ]

[Dan St Gean]

I like the low tech approach too and don't want to overly complicate the rig. However, cranking on a manilla line to flatten a 128 square foot sail in a breeze does not sound fun. I think that the halyard sheave and topping lift sheave will be helpful to eliminate friction. A multipart 3 or 4:1 tackle isn't necessarily newfangled either. As sails got larger, all old boats tended to need the same mechanical advantage needed today. We just happen to have superior line, sailcloth, and blocks.

In my cast nothing but the design is traditional--and even that is tweaked. I am building a 21' Hawaiian canoe in cedar strip, fiberglass, and epoxy. The outriggers (yes it will be a tri under sail) are shaped foam with fiberglass and epoxy. The rig will be aluminum and hollow birdsmouth douglas fir once again build with epoxy. Controlling the rig using manilla line and 1:1 purchase does not make sense here. Even with "all the hardware" I'll need two blocks for a downhaul and two for the snotter. The lack of friction with modern blocks and line will be welcome, and the additional purchase will be helpful as well.

As for shooting the sprit through the anchorage, I guess it could happen. My sail will have both a clew ring as well as a webbing loop that will retain the aft end of the sprit. Controlling 128 feet of sail won't be so easy as 60 or 80 that many of the comparisons are indicating. The sail designer Graham Brynes at B and B Yacht Designs knows about as much about sprit boomed leg o muttons as anyone, and after a conversation yesterday indicated that 3 or 4:1 on the downhaul would be appropriate and 3 or 4:1 on the snotter would also work well. As for the main sheet once again three or so would work well. Since it is not a common rig nowdays, I need to consult folks that are still using the rig. Thanks to all of you who have given me something to chew on while I finish up building the mast and deciding on the rigging. I'll have to get some shots to share once I get the boat a little further.

Sincerely,

Dan St. Gean

[DougWilde]

A shot of the snotter on Bessie Lee at the Chesapeake Bay Maritime Museum. Sorry for the small image but I cannot lay my hands on the original to scan it larger.

http://dbwilde.home.comcast.net/BoatScans/BLspritboom.jpg

You can see how on this working boat the snotter runs from a fixture on the mast, out to the fork, then cleated to the side of the sprit. That fixture also serves as a sheeting point for the main.
By passing the snotter through a grommet on the luff I place everything outside sail track, lacing, etc.

Dan, whatever you do please take pictures and post back here. Up to date info on sprit sails such as we are discussing is, unfortunately, quite rare. I had a hell of a time while building in NW Arkansas!

Doug

[Dan St Gean]

I'll do just that. I have't any pictures here at work, but I do have a link to Gary Dierking's Ulua. Worth checking out although I 'm stretching it from 18' to 21', more than doubling the sail area, and increasing ama length and volume. I'll get some pictures of the mast building this weekend.

Dan

[Dan St Gean]

Whoops! Here's the link.

http://homepages.paradise.net.nz/garyd/ulua.html

By the way, the length stretch is done with Gary's blessing--in fact he has the go ahead to stretch it to 36' if one wants. The larger fir is just to make it a little faster than my Wave.

Dan