The use of mechanisation and the latest cored wire technology in the construction of 32,000 tone production jack-up

摘要

In January 1997 Barmac was awarded the contract for the TPG 500 Production Utilities Quarters PUQ) Jack-up structure for Elf s Elgin Franklin development. This brought the company into new areas of fabrication design with similarities both toexisting fixed offshore structures and shipbuilding albeit to more rigorous standards with respect to the latter.This contract represents the first of its kind to be built in the UK.As part of the TMB consortium with Technip Geoproduction and McDermott Marine Construction and under a gainshare alliance contract the fabrication work scope is valued at over￡140 million. Figure 1 shows an artist's impression of the completed structure.Designed to stand in 90 metres of water supported by three 140 metre long triangular lattice structure legs fixed with six piles per leg,the overall Jack-up structure weight of 32,650 t can be split roughly in three equal measures between the Legs, Hulland Topsides facilities. The triangular legs which are constructed from Super Elso 400 and API-5L-X60 steel also incorporate the high strength Super Elso 700 Rack section for raising and lowering the platform. The Hull and Topsides areas in particular,required innovation in fabrication techniques and welding processes in order to satisfy the needs for volume production of panels to a consistently high standard together with high volumes of associated pipework in various sizes and materials.The high potential for distortion of panels was recognised at an early stage and played a significant part on the selection of optimum welding processes I procedures in order to enhance dimensional control, through increased welding speeds, decreasednumbers of weld passes and consequently lower levels of heat input leading to balanced welding techniques.