Introduction of portal crane

A cantilever crane, the bridge of which is supported on the ground track or foundation by legs on both sides. It runs along the ground track and can pass through railway vehicles or other ground vehicles below. A cantilever crane has a rotatable lifting device mounted on a gantry. The four legs of the gantry form four "door openings" for railway vehicles and other vehicles to pass through. Portal cranes mostly run along the crane tracks on the ground or buildings for lifting and loading operations. A crane with a serrated gantry is called a semi-gantry crane. One side of its running track is set on the ground, and the other side is set on the building above the ground.