Some years ago, I was approached by the shop teacher at the Friday Harbor High School about helping with a boatbuilding
program at the school. They were looking at building a boat somewhat larger than this, and a lot more complicated. We
discussed the pros and cons of the more complicated project. We came to the conclusion that something that could be
quickly built would produce more sense of accomplishment in the students.
|Design Number 176|
With this thought foremost in our minds, we created a design that could give the students something that would go together
quickly, and not be beyond the skills that one might assume they'd picked up in the woodworking program.
This meant that complicated bevels and fits were to be avoided and simplicity was to be emphasized. The resulting design
has a virtually constant bevel cut for the chine, so this can be run off on a table saw. Any minor variations from the
bevel cut can be taken care of with the better quality gap-filling glues....
The specified materials were chosen to be readily available from a normal lumberyard's stock. Primarily they are a bit
of clear fir and a couple of sheets of ¼" plywood. Alternatively, she could be built with the stitch and glue technique
at the chines, and/or epoxy sealed and sheathed with a protective layer of cloth set in epoxy.
This sort of boat does best if kept light, so she is easily lifted aboard or onto a car-top for transporting. Thus,
resist the temptation to increase the scantlings to "make her stronger" or to match the size of the materials on hand.
Keep the towing eye low, as shown. Be sure to fit the skeg shown for best results towing her. Otherwise, she'll wander
or yaw from side to side on a towline.
If a sailing rig was wanted, something like that shown for the 8' Portland Yawlboat would
work, using her rudder and daggerboard details too.
|Length overall||7'-3"||2.21 m|
|Length datum waterline||6'-93/16"||2.06 m|
|Estimated structural weight||45 lbs.||20 kg.|
|Displacement, to DWL||205 lbs.||114 kg.|
|Displacement-length ratio||296|| |
|Prismatic coefficient||.63|| |
|Pounds per inch immersion||86|| |
|Entrance half-angle||35°|| |
Note: The displacement numbers are calculated to the arbitrarily chosen DWL.
The calculated ratios of displacement-length and sail area-displacement will vary widely
depending on the loading of the vessel.