keelson

[ kel-suh n, keel- ]

/ ˈkɛl sən, ˈkil- /

any of various fore-and-aft structural members lying above or parallel to the keel in the bottom of a hull.

Also kelson.

Origin of keelson

1605–15; < Low German kielswin literally, keel swine (sense relation obscure) < Scandinavian; compare Dutch kolsvijn, Danish kølsvin, Swedish kölsvin

A nautical term for the holes cut in the flooring in a ship above the keelson, to allow water to drain to the pumps.

Encyclopaedia Britannica, 11th Edition, Volume 16, Slice 6 |Various
Be careful that the ends of the boards are nailed to the keelson at the opening.

Harper's Young People, February 1, 1881 |Various
Saw out the mould carefully, and in the centre of the bottom cut a mortise two inches by one-half for the keelson to fit in.

The Boy Craftsman |A. Neely Hall
And besides, he was rigged out from main truck to keelson in the nobbiest clothes that ever saw a fo'castle.

Some Rambling Notes of an Idle Excursion |Mark Twain (Samuel Clemens)

A sudden shift of the rudder shook the Vulcan from peak to keelson.

The Cruise of the Dry Dock |T. S. Stribling

keelson

/ (ˈkɛlsən, ˈkiːl-) /

a longitudinal beam fastened to the keel of a vessel for strength and stiffness

C17: probably from Low German kielswin, keel swine, ultimately of Scandinavian origin