Duckworks - Projects
The Online Magazine For Amateur Boat Builders

12' Keelboat
Design Number 93
design by Jay Benford

12' Keelboat in ferro-cement
built by Jay Benford.
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 " 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'-4" 1.03 m
Freeboard: Forward 1'-7" 0.50 m
Least 1'-0" 0.30 m
Aft 1'-1 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.