Lays out and fabricates metal structural parts, such as plates, bulkheads, and frames, and braces them in position within hull of ship for riveting or welding: Lays out position of parts on metal, working from blueprints or templates and using scribe and hand tools. Locates and marks reference lines, such as center, buttock, and frame lines. Positions parts in hull of ship, assisted by RIGGER (ship-boat mfg.). Aligns parts in relation to each other, using jacks, turnbuckles, clips, wedges, and mauls. Marks location of holes to be drilled and installs temporary fasteners to hold part in place for welding or riveting. Installs packing, gaskets, liners, and structural accessories and members, such as doors, hatches, brackets, and clips. May prepare molds and templates for fabrication of nonstandard parts. May tack weld clips and brackets in place prior to permanent welding. May roll, bend, flange, cut, and shape plates, beams, and other heavy metal parts, using shop machinery, such as plate rolls, presses, bending brakes, and joggle machines.