XD03.13 Industrial Rigging and Signaling Practice Exam

Spanning the width of the runway is the bridge—the main horizontal structure that travels across the two runway rails and carries the hoist trolley. The end trucks on either side ride on the runway rails, and as they move, the bridge extends from one side to the other, enabling the hoist to reach any position across the width. In crane terminology, the girders that make up the bridge form its cross-section, but the term for the component that spans the entire width is the bridge. Beams and girders are parts of the bridge’s construction, and a truss is one possible structural form, but the function of spanning the runway’s width is fulfilled by the bridge assembly.