schwimmfaehige steplessly adjustable working platform for the drilling operation in great water depths

摘要

1517217 Offshore platforms MANNESMANNROHREN-WERKE AG 1 Sept 1975 [2 Sept 1974] 35956/75 Heading E1H A jacket for an offshore platform comprises a foundation 4, a lower buoyancy member 3, an upper buoyancy member 2 and a floatable working platform 1, which are adjustably interconnected by first and second support systems 5 and 6. In operation, the assembled jacket is floated to a site, possibly with the foundation partially lowered for stability, the foundation is then lowered on to a sea bed, and the members 2 and 3 ballasted to adjust their vertical position so that the platform 1 extends above the water level. The outer support 6 is fixed to the foundation 4, and the members 2 and 3 are adjustable thereon, e.g. by rack-and-pinion mechanisms, and the support 5 is fixed to the member 3 with the member 2 and platform 1 adjustable thereon. The member 2 can be formed as a ring which is braced internally. The foundation can have additional weights to improve its stability. The positions of the support systems 5 and 6 can be reversed.