The gantry crane, also known as a bridge crane, is a type of crane where the bridge is supported on the ground track by two side legs.

The structure consists of the gate frame, large vehicle running mechanism, crane trolley, and electrical components, etc.

Some gantry cranes have legs only on one side, supported by the factory or pier on the other, known as semi-gantry cranes.

The overhead bridge of the gantry crane, including the main beam and end beam, the legs, and the lower cross beam, etc., constitutes the structure.

To expand the crane's operational range, the main girder can extend beyond the support legs on one or both sides, forming a cantilever.

Also, a crane with a boom arm can be used to expand the crane's working range through the boom's pitch and rotation.