| 摘要 |
A crane apparatus and method are described for lifting a heavy load such as a wind-turbine generator unit 46 on to a wind-turbine tower 1. The crane is designed to climb up cables 3 attached to the top of the tower, carrying with it the cables 45 and lifting gear 31 which will be required for the main lifting operation. The crane comprises a pair of jib-frames 20 with boom arms 26, 27 which can be retracted during lifting and then deployed to a pivotable, loadbearing position once the crane is mounted at the top of the tower 1. Hydraulic strand jacks 31 and heavy-duty strands 45 are preferably used for the heavy lifting. In a preparation step, a load-bearing bracket assembly 13, 14, to which the jib-frames 20 will be secured, is hoisted up and fitted to the top of the tower 1. Once the lifting operations are complete, the crane assembly and the bracket assembly 13, 14 are lowered from the tower 1 and removed from site. |
