Gantry crane is a variation of bridge crane, where the bridge is supported on the ground track by the legs on both sides. It can be adapted to both indoor and outdoor applications to lift and move heavy loads or materials. With the characteristics of high site utilization, large operating range, wide adaptability and strong versatility, gantry cranes are frequently used in port and cargo yards. Its picking device can be a hook, grab, electromagnetic chuck, of which two or three of them can be used at the same time for increased work efficiency and flexibility.