Sailing in Maine

Sailing in Buzzrds Bay

Tuesday, October 21, 2008

Finalizing the Design

I've made a number of sailing canoe designs in Hulls using 2, 3, and 4 panels per side. By careful arrangement of the panels, I can fit the parts for a 13' x 32" canoe on three sheets of plywood. I'm concerned this is not quite large enough for two people, so I'm going a little larger.

I love the look of the sailing canoes from the golden age of canoeing in this country about a hundred years ago. There is a certain romance about them seldom seen in more modern craft. Several designs have appeared in Wooden Boat Magazine and elsewhere.

One particular design that appealed to me was the Yakaboo, which is preserved at the Bruce Mines Museum in Bruce Mines, Ontario. According to the museum "The Yakaboo was a cruising canoe, designed and built by W.F. Stevens (Stephens), some say it was designed by Frederic Fenger. It was 17 feet long, 39 inches wide, and weighed 147 pounds. It had no rudder, but was maneuvered by trimming the sails and shifting the centerboard forward or aft as required. Frederic A. Fenger sailed the Yakaboo 800 miles in the Caribbean Sea, from Grenada to the Virgin Islands, in 1911. He wrote a book on his experience, called "Alone in the Caribbean", first published in 1917."

Frederic A. Fenger aboard Yakaboo. You may read about his adventures here.

The lines plan of Yakaboo appeared in Yachting magazine at about the time "Alone in the Caribbean" was published. It showed a low, wide hull with a central cockpit surrounded by a coaming. Replicating such a hull in plywood could be done with 3, 4, or 5 panels per side. I've decided on 4 panels as a reasonable compromise between looks and building time.

I've made a Hulls model to check the basic design. It has enough rocker to tack well, and enough "keel" to track reasonably well when paddled. The prismatic coefficient is midway between the Selway-Fisher 50-50 Canoe and Michael Storer's Beth, for reference. By rescaling it to 90% of the original size, I have a 15 1/2' x 36" design which can fit on four sheets of plywood. Since each sheet weighs about 10 lbs., it should be light enough for easy cartopping. One of the features of Hulls is the ability to make a VRML solid model of the wireframe model, and view it in a browser (above). This allows me to check for any prominent crease lines in the panels that need to be smoothed out.

By importing the Hulls model into FreeShip, I can do further design checks. The stability curve is similar to the 32" wide Beth, but with only 81% as much wetted surface, which will aid light wind performance and ease of paddling.

There will be two bulkheads eight feet apart, which will define the length of the cockpit and allow internal stowage of a double paddle. I'm targeting a weight of 45 lbs., using 4 mm Okoume plywood covered with 6 oz. glass cloth and epoxy. I've had to square out the stern to take a rudder, as the original had none, and the cockpit has been lengthened to hold two people. Clamp-on leeboards will replace the original movable centerboard.

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