Sailing Rig for Chamberlain Gunning dory

[Lazy Jack]

How much sail area is required for the Chamberlain gunning dory? I searched through previous posts, some found that the rig drawn by Gardner was a bit anemic, but where I plan to use mine can become pretty breezy in an awful hurry. I'm looking for a rig with: reasonable (subjective I know) windward ability, Short spars to be easily stowed in the boat, good power for light airs yet quickly and easily reefed in a blow, able to drive the boat at her 4 to 5 knot hull speed without inducing such a heeling moment as to frighten off those new to sailing, and above all simple. Gunter, leg o mutton, sprit and sharpie type rigs are all appealing, which one would best meet my requirements? I do not have much first hand experience with which to compare these various rigs.

I have also, for the sake of simplicity, decided on a solid wooden daggerboard glued up of white oak culls and resourcinol. Would planing it to a foil in section be worthwile or is that akin to putting airdams and spoiliers on a station wagon? Any input would be appreciated. Ian, how are you coming with that junk rig?

[Yanis Abols]

I am building a Chamberlain gunning dory in my garage here in Normandy. I haven't solved all my building problem's yet, and will have questions for the forum in the weeks to come.
Concerning the sail plan I had the intention of using a traditional standing lug, which seemed to me the most simple option as I will sail single handed most of the time. I was planing on the following dimensions: 10 square meter cotton sail, mast length: 4.5 m , approx. 14'9'', yard length: 3.7m approx. 12'2'', mast rake 7°,angle between luff and yard approx 24°.
I would greatly appreciate any comments.
Yanis.

[Yanis Abols]

Sorry, forgot to translate the square meters. 10m2 = a little over 100 square feet.

[Thad]

The gunning dory is a very easily driven vessel. How much sail area you require will depend a lot on the winds in your area. One of the best things about the lug rig is the short length of the spars. Depending on where you step the mast you may or may not want a jib. I would want reefing capability in an open boat of this sort if you have enough sail to go well in light air. Yanis, are you building to Chamberlain's plan or Gardner's? I would like to think Chamberlain's because of the subtlety of his lines. Gardner redrew the boat symetrical fore and aft, to make lofting and plywood cutting easier I think. Good luck and have fun both of you.

[ishmael]

Am I imagining things (more and more possible) or did Pete Culler have a second book after Skiffs and Schooners, where he discussed various dory rigs? Maybe it WAS Skiffs and Schooners, but he, later in life, experimented with a wide variety of rigs for dorys. Kind of a hobby/obsession if I remember correctly. Well worth searching and sorting out what I'm not being very helpful with... Best, Jack

[Ian McColgin]

I do not recommend a dagger board as it reduces your flexability in loading and handeling by freezing that aspect of the center of underwater lateral resistance. Also, a daggerboard is a bit more of a jolt when you scrape the beach.

It's too cold and dark to get out my sail and measure it but it's a whole lot bigger than the bigger one Gardiner drew. It's a kind of sliding gunter made from sailfish spars. The luff is about 3' longer than either lanteen spar. It's shaped more or less like the Swampscott shape he drew except that the spar I use as a kind of lateral sprit in place of the boom is the other lanteen spar from a 'fish. In the unreefed position, it projects infront of the mast about 1'. The reefed version puts the luff exactly the length of the spar (the hallyard must be moved higher up the spar) and the clew is porportionatly higher. Then the sprit-boom sticks out ahead of the mast by about 18".

Unreefed it's good to almost 15 kt. Reefed I've sailed in 30 kt. I weight 250#.

Unfortunatly, this rig pretty much precludes a jib, which she really can use of balance. Sometimes to tack I have to really lean back in the stern sheets. That's why I'm into the idea of trying to put that sail area into a junk rig, which will move the SA forward a bit.

Anyway, as I've mentioned before, great little boat. Now that I'm writing, I can't get to your ID to see if you've posted your location, but if you're within strike of Cape Cod, trailer her down some summer weekend. We'll tow 'em both behind Grana to some great dory spots, like the slot above Monomoy and the immediate surf near the seal haul-outs.

G'luck

[Will]

Thad ; where would one find Chamberlains original plans ? I've wondered that in the past because Gardiner mentions shortening the boat to 18 ft. at his clients insistance , but I had no idea he'd made other changes as well .

[Lazy Jack]

Thanks for everyone's input! I need to learn more about the lug rig. Ian, I hear your recommendation against the daggerboard loud and clear. I understand why it is important to be able to shift the center of lateral resisance for different sailing conditions, something most centerboards can't do either. I plan to solve this by having a long daggerboard trunk supported between frames two and three by the after edge of thwart two and the foward edge of thwart three. This will give me a trunk whos length is almost three times the width of the daggerboard. I can place the daggerboard anywhere in the trunk and fix it in position with crushable spacers either side in case I bottom out hard. This arrangement will allow me a longer board than I could get with a centerboard which must fit inside the trunk when stowed. All of these considerations, however are rather trivial compared to my aversion against having to cut the overlapping floorfuttocks of frame three to let the bedlogs for the centerboard trunk run by. Because everything was screwed and epoxied together on my boat, cutting this away and rejoining the ends of the frames securely to the bedlogs would be a major PITA! I also plan to build a larger rudder to move the CLR even further aft.
I actually plan to bring her down to Cape Cod this summer, I'll let you know when.

[PugetSound]

Lazy Jack, why not try Phil Bolgers method of making a removable leeboard -at least until you figure out exactly what works best for you. I recall that the gunning dory is a really beautiful boat but, at 18+ feet, it isn't all that big. Anyway, the removable leeboard may seem clunky but it beats carving up your boat only to find that you really didn't want it that way.

[Thad]

With small boats of this sort you can adjust the CLR easily by shifting moveable ballast (like yourself) fore or aft in the boat. You can also rig the daggerboard at various depths with a similar effect. I see the tradeoffs in the c-boards ability to pivot up when you take the ground and having the board contained. For the daggerboard is the short length of the trunk with more free space aboard. Balance and turning ability will depend considerably on the placement of either device.

[Lazy Jack]

Thanks for the input. My concern really isn't how or where to place the daggerboard. That can easily be figured out once the configuration of the rig is decided. From that, the center of effort of the rig is caluculated and then I'll plan to adjust the placement/size if the centerboard and rudder so their combined areas place the CLR about 15% behind the center of effort. The hull itself is not considered because being symetrical, the CLR of the hull is amidships. The cargo weight and placement is so variable that I am leaving that out of the equation also. So, My first issue at hand is: What kind of rig, and how much area?

[David Shipway]

I pretty much stuck with Gardner's traditional scaled-down alpha sailplan and am still very happy with the overall performance, eight years and many coastal journeys later. I need to make a new set of sails now, and would definitely batten the roach. Any taller or more complicated rig would be potentially disastrous. I load up with rocks when the wind gets really strong, since reefing isn't practical with the leg-o-mutton. I can send you a picture if you email me @ shipway@island.net :cool:

[Jeff Evans]

Would anyone ever put a gaff rig on a dory? Perhaps it would be impractical, but I have a certain romantic attachement to them. Perhaps others feel the same way.

[Will]

David ,please post it here if you can . That's just the kind of post that's interesting .Would you send it to me in any case ?

[plimsol]

The father of a ship mate of mine discarded the Alpha -rig and set the boat up with a sliding gunter ketch rig. It worked very well, he sent us post cards from all over British Columbia. He found that a tall single mast was not shipable from within the boat and that a long mast made it almost impossible to row. With the ketch rig, he could balance the boat and stow the rig for rowing. Good luck with the project.