Entry 5

by David Beede  juliejj@nersp.nerdc.ufl.edu 

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My entry into the Duckworks contest is an 11'8" long 50" beam 16" sides, high capacity skiff reminiscent of the turn of the century flatiron skiffs. I know the contest guidelines urged us to stress specific use, but since this was conceived as a community boat building craft, what I've tried for is versatility and ease of construction. No lofting is required and all saw cuts are straight. The "bump" where the sides rise to the transom is smoothed out with plane, rasp or sander. The chine log, PL premium and bronze nail construction keeps young fingers out of Epoxy and glass, though she can be stitch and glued and glass sheathed if conditions warrant. 

She's a pleasure to row, and I have several times hit 7.5 knots with her humble polytarp lug sail in moderate breezes. Though I've only had my wife and I, our dog and a picnic in her as yet, her leeboard creates wide open sprawling space enough for a bed roll to a dedicated small boat camper.

Though I didn't have more than an electric trolling motor in mind when designing her, one builder has had fun with a 4 horse kicker on his version of this boat.

SBviews2.gif (3194 bytes)  Here are the three views. I'm no artist so the photos of the model and the boat will have to do.

And here is the way the sheets of ply and board stock are utilized. 

   You'll notice that the waste in the side layout sheet is the saw dust from the kerfs. This sheet also provides butt blocks, skeg, oar blades and quarter knees.
 bottomlayout.gif (6975 bytes)  The rotated triangles in the bottom layout is what make it possible to get such a large bottom section from one sheet. Gussets, mast step, leeboard backing and bow butt blocks also come from this sheet.
 gluebot.jpg (6422 bytes)  Here's photo of the bow triangles and their butt blocks.
 boards2.gif (22756 bytes)  Using solid stock for the transom allows maximum bottom and sides from ply, and makes for a respectable capacity skiff without going to a pram bow.
 gussetstem.gif (5089 bytes) The stem can be made of solid stock, but this resaw sandwich method uses the least wood. The ply gussets are sandwiched between the bottom and side frame members.
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 Here are the sketches of the frame. The shaded version below should make it clearer how the gusset is sandwiched.
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Gunnels and chine logs...

 chinegundetail.jpg (32048 bytes) The photos show split gunnel and inwale set up, but this single gunnel is simpler and sufficient. The chine log is not necessary if the bottom is stitched to the sides.
 TSSrig10mast.jpg (16224 bytes)     I had to laminate a couple of pieces from one of the 1" boards and scarf to the 2x4 to get the 10 foot mast I wanted. One pole is used for the upper spar of the lug sail. I was going to use the other for the sprit boom, but someone mentioned that in this contest, a row boat needed to make the oars from the material (you can specify a purchased motor, but not oars?) So now the sail is either loose footed in the chine log version, or if she's stitch and glued together the chine log material can be used as the sprit boom. Sail making details are HERE.
 gluebot.jpg (6422 bytes)  Here's photo of the bow triangles and their butt blocks.
 SBskegslot.jpg (5703 bytes)  The laminated ply skeg slips into a slot in the keel making fitting it to the bottom simpler.
 SB3.jpg (4888 bytes)  In spite of all the straight cuts, to my eye, her finished lines are sweet and flowing. One of the small miracles of boat building.
 hullsdisplace3.jpg (28401 bytes) Here's a screen shot of Gregg's Hull program showing the displacement at 569. The water line just touches the stem and transom here. At 650lbs it not even an inch higher, but seems like pushing it. Displacement, of course includes the weight of the hull. Capacity is how much she can hold, which is over and above the weight of the hull. Since the finished boat weighs about 60 lbs, I've estimated her capacity at 500 lbs. This is an upper limit figure and I expect her rarely to be that loaded. 
 sbdavidrow7S.jpg (9131 bytes)  She trims fine for rowing.
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 This is the motor boat version.

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Ultra Light Rowing Version -

This is a fantasy of an ultra light version that is a simple approach to lapstrake building. The lap gluing is done flat on the floor, the gunnels and the chine logs are attached and the side is bent as an assembly. (I know this sounds far fetched but Steve Redmond used this approach in his skiff Whisp.) The side sheet is 1/8" ply. 1/2" overlaps provide added stiffness. The gunnels are notched (1/8" x 3/4") to enclose the top of the sides, a la Herb McLeods OSS. This seals the top of the ply sides and extends the height of the side 3/4" to make up for most of the inch  lost in the laps.

lapsides.gif (2922 bytes)  In this case I would temporarily hold the side panels together with duct tape while cutting the strakes.  The bow and stern are divided in thirds then a batten or PVC pipe is used to draw the curves of the strakes. Cut with a thin saw blade, saber saw, or even a matt knife. 1/4 staples can be used to "clamp" the laps. The strakes could be skarfed with epoxy and 2" tape rather then 1/8" butt blocks. 
 rowboards.gif (5650 bytes)  I confess this board layout was done before the Duckworks contest so it calls for one 12 foot 2x4. In keeping with the rules, we will scarf it from the two 8 footers allowed. For oar locks I glue 3/4" thick blocks to the gunnels with stainless deck screws, then drill a 1/2" hole lined with half a brass grommet for canvas works. This really works!

linelapdraw3.gif (3247 bytes)     A sketched view.

 SB1.jpg (4527 bytes)  This was the proof of concept 1/4 sized model done in 1/8"  

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