According to different utilization levels and load conditions, the work duty can be A3-A7. All the crane operations are controlled in the driver’s cabin. Double Girder 75 Ton Overhead Crane. Double girder 75 ton overhead crane parameters: Span: 10.5-31.5m. Lifting height: 6-24m. Lifting speed: 2.1-11.5m/min. Trolley running speed: 27-40m/min.