A gantry crane, also known as a bridge crane, is a type of crane with a bridge that is supported on the ground track by two legs on either side.

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

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

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

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

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