Abstract: 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.

Abstract: A method is described for threading a tendon into a duct from an opening at an intermediate point along the length of the duct. Opposite ends of the tendon are threaded from a reel into the two halves of the duct. The tendon is wound on to the reel such that both ends of the tendon can be unwound into the duct simultaneously. A reel and a method for winding the tendon on to the reel are also claimed. The method and reel are particularly suitable for threading coated steel tendons into PT ducts in tall structures such as containment vessels.

Abstract: 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.

Abstract: A method of constructing a tower structure by assembling a set of coaxial telescopic sections 2, 3a, 3b in position on site and then raising the assembled sections using hydraulic crawler jacks 8 and tendons 5. The telescopic sections are assembled or constructed in situ, starting with the inner section and then each subsequent section around the outside of the previously constructed sections. Each individual tower section may be cast in situ or assembled from multiple pre-fabricated segments. This method permits the construction of very tall structures while obviating the need for very large cranes. It also removes the design constraints on the height of the individual telescopic sections.

Abstract: A method is described for threading a tendon into a duct from an opening at an intermediate point along the length of the duct. Opposite ends of the tendon are threaded from a reel into the two halves of the duct. The tendon is wound on to the reel such that both ends of the tendon can be unwound into the duct simultaneously. A reel and a method for winding the tendon on to the reel are also claimed. The method and reel are particularly suitable for threading coated steel tendons into PT ducts in tall structures such as containment vessels.

Abstract: A method of constructing a tower structure by assembling a set of coaxial telescopic sections 2, 3a, 3b in position on site and then raising the assembled sections using hydraulic crawler jacks 8 and tendons 5. The telescopic sections are assembled or constructed in situ, starting with the inner section and then each subsequent section around the outside of the previously constructed sections. Each individual tower section may be cast in situ or assembled from multiple pre-fabricated segments. This method permits the construction of very tall structures while obviating the need for very large cranes. It also removes the design constraints on the height of the individual telescopic sections.