40 ton insulating crane is Double Girder Overhead Crane, which is applicable to workshop where smelting electrolytic nonferrous metal material, such as electrolytic magnesium. The overhead crane is composed of box bridge, running gear, trolley and electric device. Several insulating apparatus are mounted at proper parts of the crane to prevent the electric current of the energized equipment transmitting to the crane through the lifting hook during operation, which will endanger the driver's life and the safety of the crane. This 40 ton insulating crane is heavy-duty. ,Main mechanism equipped with dual driving for the purpose of safe hoist.