rung-headn.

a1625 H. Mainwaring Nomenclator Navalis (Harl. 2301) Rungheads are the heads or endes of the Rungs... Also more generally, the outward ends of Hooks which are in the same manner compassing are called Rungheads; for the Sleeper which is boulted into the other Rungheads is also boulted into theise, and they saie it is bolted fore and aft to the Rungheads.

1691 T. Hale Acct. New Inventions 48 The reaching of the Ship crackt every seam of her from the rung-heads upwards.

1705 tr. G. Guillet de Saint-Georges Gentleman's Dict. iii. Rung-Heads, a peculiar Name given to those Heads of the Ground-Timbers of a Ship, which are made a little bending.

1769 W. Falconer Universal Dict. Marine Rung-heads, a name sometimes given by shipwrights to the upper ends of the floor-timbers, which are otherwise more properly called floor-heads.

1844 Dict. Trade, Commerce & Navigation Rung heads, the same as floor heads, or the upper ends of the floor timbers.

1863 A. Young Naut. Dict. (ed. 2) Rung~heads,..a name formerly given to the floor-heads.

1961 C. Gill Merchants & Mariners 18th Cent. vi. 63 Wrongheads, or rungheads, were the joining of floor timbers to the ribs of the hull.

2001 B. Leonard in R. Garvey To build Ship iii. 14 Once the keel, stern and sternpost were set in place, the hull was planked out to the rung-heads (the turn of the bilge) before the floors were installed.