Sister-Keelson

Long pieces of timber connected endwise by scarphs; — placed on each side of a main-keelson, and extending as far forward and aft as practicable, for the purpose of giving additional strength at the middle-line of a ve el: - they are fastened by through-bolts horizontally to the middle-line-keelson, and vertically to the floors. See Plate 12. e.