12' Keelboat
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Design Number 93 1972 |
In the early '70's, when it was socially acceptable to be designing in ferro-cement, we did quite a number of designs
in that medium. The ones done under our supervision, with our techniques and methodology, turned out quite well,
usually with such a fine finish on them they often were taken for nicely built wood boats.
Then, within a few years, the results of Samson Marine's marketing caught up with even the good ones, ruining the
resale value for one and all. They'd claimed that anyone could build in the medium and do it quickly and cheaply.
Unfortunately, the results looked like they'd been taken literally. Crude finish work and detailing abounded. They
were difficult to sell for even the cost of their materials. The boating community at large assumed that anything
that was built of ferro-cement must, by definition, be one of those crudely built boats and didn't want to be
associated with them.
We'd always done designs in other materials. These other materials are what we're working in today. We still sell
the occasional ferro-cement plan (almost always overseas), but I won't do it without raising my concerns about the
resale situation.
12' Keelboat in ferro-cement built by Jay Benford.
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This 12' Keelboat was designed while we were heavily involved in doing ferro-cement designs and was part of an
ongoing materials testing and design evolution program. Samson claimed that building a boat under 30' was not
practical, but we'd already done a 17' Catboat. The data we'd gotten from the test lab work proved correct in
the success of this boat too.
Living in the Pacific Northwest at the time, we had no concerns about draft. We thought we'd try out a small
keelboat that would be a good performer. The shell thickness was well under ¼" and she was quite flexible without
the gunwale reinforcement.
Today, I think something like this ought to be cold-molded, and the structural detailing of the 11' Oregon Peapod
might work well for her. Living on the shores of the Chesapeake now, I appreciate more of the virtues of shallow
draft, and would think about a centerboard or daggerboard.
Particulars: | Imperial | Metric |
Length overall | 12'-0" | 3.66 m |
Length datum waterline | 12'-0" | 3.66 m |
Beam | 5'-0" | 1.52 m |
Draft | 3'-4½" | 1.03 m |
Freeboard: | Forward | 1'-7½" | 0.50 m |
Least | 1'-0" | 0.30 m |
Aft | 1'-1½” | 0.34 m |
Displacement, to DWL | 860 lbs. | 391 kg. |
Displacement-length ratio | 222 | |
Sail area | 125 sq. ft. | 11.61 m2 |
Sail area-displacement ratio | 22.0 | |
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.
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