society > travel > travel by water > vessel, ship, or boat > parts of vessels > body of vessel > bottom or part under water > [noun] > keel and kelson > keel > inner keel (3)
kelson?1611
A line of timber placed inside a ship along the floor-timbers and parallel with the keel, to which it is bolted, so as to fasten the floor-timbers…
sister keelson1806
a second keelson running parallel to the main one, and providing additional strength.