Low Tide

Yacht Designer Tad Roberts' Web Log


Sister Keelson drawing
Sterling Shipyard drawing of sister keelsons

Sister Keelson installation by Sterling Shipyard. The sister keelson’s were a west coast substitute for floor timbers, adopted to do the floor’s job and deal with some other problems. Floors do at least two things; connect the two sides together across the centreline, and connect the keel to the hull bottom. The sister keelsons do those things too, as well as adding a lot more longitudinal strength and stiffness, which was important in boats that often had unplanned encounters with terra firma. The other advantages are the lower shaft line possible, and the open alley along the centreline for all the fish guts to accumulate in an easy to clean out area.