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Why the balanced lug?

Posted: Mon May 21, 2012 6:24 am
by johnmcneely
One of the things that impresses me about the SCAMP is that it is a blend of the old and the new. Its lines are certainly salty, but form the plans, John Welsford incorporates a lot of safety and stability; perhaps the culmination of what humankind has learned about the design of small boats. But I am intrigued by the selection of the balanced lug. Could those who know comment on why it was selected. Visual considerations may have had something to do with it (a very modern sail design might just not have looked right on a SCAMP). I own a Hobie Mirage Tandem Island (sailing kayak trimaran). It has a 90-sq ft sail that is loose footed and boomless. (See photos at: http://www.hobiecat.com/kayaks/mirage/t ... nd/photos/ It furls around the mast with the pull of a line. Its Battens are vertical or semi vertical. It uses a two-piece Carbon-Fiber mast that is 18-ft tall. The bendiness at the top of the mast is purposeful because as it bends it spills wind when becoming overpowered. The bottom fourth of the sail is transparent so the skipper can see. I grant you, it does not look salty. But my perception is that the balanced lug is harder to reef and more complex overall. But then, what do I know. —John

Re: Why the balanced lug?

Posted: Mon May 21, 2012 8:15 am
by Monies
Mike has sailed extensively the Michalak Laguna with twin balanced lugs and now the Scamp, plus a few miscelaneous balanced lugs. He swears it is the easiest sailed sail/boats he has ever sailed, and he has loved them.

After the Sail Havasu event in February, he said he would never go back to "modern sails or rigged boats" because all he has to do is push the tiller over to tack, no winches, no complex lines/halyards, and so on. He said it was hearing all those people churning winches, pulling all those lines around.

Apparently the Scamp is easy to reef too because Mike has had to reef in some heavy weather more than once while under sail.

One person who we think is very knowledgable about lug sails is Michael Storer who has a lot of information on rigging and sailing lugs on his website, his Goat Island Skiff is a lug. Think his site is www.StorerBoats.com. I have asked Michael Storer to hold a short seminar of about an hour at Sail OK! this year, but he should have plenty of lug sails available to demonstrate with!

I think a short answer is ease of rigging and sailing, plus all of ours are big honking footage sails on small boats! We have 100 square foot lugs on our Oz Racers by Storer. Which are 4 x 8 rectangles for hulls. Those guys like big sails.

Jackie Monies http://groups.yahoo.com/group/SailOklahoma/

Re: Why the balanced lug?

Posted: Mon May 21, 2012 6:17 pm
by JohnT
A balanced lug has several very good features for a small boat.

--It uses short, easily stowed spars.

--It provides a lot of sail area which is lower than a marconi rig. This minimizes heeling.

--It is more or less self vanging.

--Since a portion of the sail is forward of the mast (and pivot point for the sail), jibes are fairly gentle and the rig is less subject to the rhythmic rolling which can occur when running downwind.

--The rig does not require much in the way of expensive hardware.

--Finally, there is very little to hang up and the sail will come down reliably.

Re: Why the balanced lug?

Posted: Tue May 22, 2012 5:48 pm
by Johnny Walker
I would be inclined to think that a Cat Ketch rig offers all the simplicity while keeping each sail under 50 sq.ft. Offers quick reefing and lighter tackle. On #24 I'm using folding wind surfer spars allowing the whole rig to slide into an 8'3" bag and nest within the cockpit. A stock Boston Whaler 13' canvas cover from Cabela's snugs over the entire rig without a wrinkle. Johnny

Re: Why the balanced lug?

Posted: Thu May 24, 2012 6:15 am
by kenjamin
Hey Johnny,

Good luck with your ketch rig. It will be interesting to see how it performs in comparison with SCAMP's big as-drawn lug. My SCAMP's birdwing rig will also be a departure from the lug. Like you, I'm using a mast from another project and trying to make it work with the SCAMP. My rig will be a bit undersized so it will not compare favorably with the big lug in light air but like you I think my rig will be able to step or strike at sea. This will be a good thing for a fisherman like me who will want the mast down for fishing. Because my main sail is so undersized I'm designing a retractable bowsprit to add sail area which will greatly increase the complication but should also add greatly to the performance. I don't think either one of us two guys should expect the same kind of performance the big lug offers. First and foremost, the lug is huge and will always do well in light air and is the ultimate in simplicity during operation. Anyway, just wanted you to know there will be other alternate rigs for the SCAMP out there but it's going to be tough to match the combination of performance and simplicity that the big lug offers.

Re: Why the balanced lug?

Posted: Thu May 24, 2012 7:18 am
by johnmcneely
My only concern, as I think about it more, about using an alternate sail plan, is that it might unbalance the rig. No doubt the designer calulated the relative position of the Center of Effort (CE) with the Center of Lateral Resistance (CLR). I knew a man who owned a Potter-15 and used a Sunfish Lateen sail on it. I never got a chance to ask if it unbalanced his rig. As I understand it, for safety reasons a boat should have ever so slight weather helm. I heard from someone, perhaps on this message board, that the balanced lug has, as one of its advantages, that this relationship (CE to CLR) doesn't change as you take in reefs. That's got to be a plus. —John

Re: Why the balanced lug?

Posted: Thu May 24, 2012 2:54 pm
by kenjamin
Yep, my birdwing rig likes to be stepped much further aft than the lug so I commissioned John Welsford for a drawing to help me locate the proper place to step the birdwing mast. So I'm in good shape as to the locations of the center of effort and lateral resistance for my experimental birdwing rig. He even drew in a bowsprit and a jib that I will be using also. I'm very grateful for John's help with the stepping of my rig on the SCAMP. If possible it's always a good idea to involve the designer with major changes especially with the rig. As I suspected my birdwing mast wanted to be stepped on the aft edge of the cabin roof but I've also planed in some adjustability at the foot of the mast step just to be able to tune it in a bit.

Re: Why the balanced lug?

Posted: Thu May 24, 2012 6:09 pm
by Johnny Walker
Thanks for the discussion. SCAMP #24's ketch rig indeed moved the CE aft. To balance this I drew the skegs level with the waterline to the stern and then on another 12" creating 11" deep skegs and a couple square feet to the aft end of the CLR. These extended skegs could be cut down if needed but also serve as a great swim deck and protect the rudder nicely. I could also cut the leech down on the mizzen to balance the helm. I'll find out in a few weeks when I quietly launch MayFly. I also plan to fish while sailing with the foremast only (stepped in the bulkhead #3 slot). I have not heard back from John Welsford. I suspect some reservations concerning my many design changes. I do plan to be at Lake Havasu next February to make amends. Johnny

Re: Why the balanced lug?

Posted: Fri May 25, 2012 4:54 am
by kenjamin
Hey Johnny,

I may have used up all of John's patience for alternate rigs with all the birdwing stuff I sent him. Fortunately for me he seems to have had some curiosity about how the birdwing mast will perform. Looking forward to seeing pictures of MayFly on the water. Fair winds.

Re: Why the balanced lug?

Posted: Fri May 25, 2012 7:32 pm
by Monies
The opening post on this thread commented that he liked the fact that Scamp combined "old and new" a modern traditional boat. One thing we noticed while showing her in Franklin, LA at the Bayou Teche Wooden Boat Show was the festival attendees kept thinking she was a restored wooden OLD boat.

We kept explaining that the Red Scamp was a new boat, that Scamp is only about 1 1/2 years old. But her classic look kept confusing people, who kept thanking us for preserving the older, traditional boats and restoring them.

We had planned to bring some of SCA's magazines and Wooden Boat with their article about John Welsford, his boats and Scamp. We forgot them in office! So, next year I plan to make up a scrapbook/album about Scamp and all the adventures of the Red Scamp. We are new to boat showing and I stole this idea from a more experienced boat showman who actually had restored a historic runabout. People could look thru his album or at the posters he had made.

So, she did fit in at the show, looked historic but is new.

Love, Jackie Monies