The single girder gantry crane for ship building is mainly composed of steel gantry frame, upper trolley, lower trolley, trolley travelling mechanism, maintenance, lubrication, elevator and electric equipment. And there are rail clamp device (or wheel actuator), anchor device, lifting weight limiter system, wind speed and direction system, limit switch of each mechanism, and the other safety protection device for this crane. The deviation rectifying system can be equipped in case of very large span.
