Underslung Crane

Single Girder Overhead Bridge Cranes. On a single girder crane, the bridge consists of one girder beam supported on each side by an end truck. The trolley and hoist are most commonly underhung—meaning they run on the bottom flange of the bridge. The bridge itself can either be top running or under running in design.A single-girder overhead crane is a type of bridge crane that consists of two or more overhead runways built into the building's support structure, with the girder (the bridge) running between the runways for the width of the crane bay.