The MG-type double-girder gantry crane is a variant of the double-girder bridge crane, primarily used for outdoor operations such as loading and unloading cargo, materials, and bulk goods. Its metal structure forms a portal frame, with two supporting legs mounted beneath the main girders, allowing the crane to travel directly on ground rails. The main girder ends can also be equipped with cantilever extensions. This design offers high space utilization, a large working range, wide adaptability, and strong versatility, making it widely used in port and freight yards.