Heavy lifting apparatus and method

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.

主权项

1. Crane apparatus for lifting a load from a base region of a tower to an elevated region of the tower, the crane apparatus comprising
crane-lifting means for lifting the crane apparatus to a crane mounting position on the tower using one or more crane-lifting cables supported at the elevated region of the tower, two boom arms adapted to be displaced outward from the elevated region of the tower, a distal region of each boom arm being provided with cable supporting means for supporting one or more load-lifting cables, a boom support frame for supporting the boom arms such that the boom arms can be arranged on either side of the tower during said lifting of the crane apparatus to the crane mounting position, or such that the boom arms can be arranged on either side of the load during the lifting of the load, the boom support frame-comprising two jib-frames linked by at least one cross-member, said jib-frames and said at least one cross-member being arranged such that the crane apparatus can be assembled straddling the tower with one said jib-frame on either side of the tower, load-lifting means supported at the distal region of one or both boom arms, said load-lifting means being for lifting the load to the elevated region using the one or more load-lifting cables, and separation adjusting means for varying a separation distance between said two jib-frames as the crane apparatus travels up or down the tower.