%mastin%

n. (Naut.) The act or process of putting a mast or masts into a vessel; also, the scientific principles which determine the position of masts, and the mechanical methods of placing them. [ 1913 Webster ]

Masting house (Naut.), a large building, with suitable mechanism overhanging the water, used for stepping and unstepping the masts of vessels. [ 1913 Webster ]