Thick pieces of timber, incurvated into the form of knees, and used to strengthen the fore-part of a ship, where they are placed at different heights, directly across the stem internally, so as to unite it with the bows on each side, and form the principal security, supporting the hawse-pieces and strain of the cables. The breast-hooks are strongly connected to the stem and hawse-pieces by tree-nails, and by bolts driven from without through all, and forelocked or clinched upon rings inside.