DESIGN OF ECONOMICAL MOORING SYSTEMS FOR LARGE FLOATING PRODUCTION PLATFORMS

Lack of practical experience, throughout the world, in overcoming problems in the design of systems for mooring large floating production platforms that have to be able to remain on station in extreme environmental conditions , together with the high cost of these systems, led to the formation of a study group for the systematic investigation of the factors that should be taken into account in the design and installation of such mooring systems. The study, in which minimising the costs of the system was given particular attention, was made by the Authors' firms in association with Germanischer Lloyd and with the support of the W. German Government, and was completed in Dec. 1981. The Authors briefly explain the methods used in the study and describe in some detail the design, as part of the study, of a mooring system and its elements, using as an example a system for mooring Consortium 76, a natural-gas liquefaction platform, in a water depth of 550 m in the northern North Sea. This mooring system is described and discussed under the headings: Components of the Mooring System; Anchoring Points; Mooring Lines; Sinkers; Chain of Flat Steel Construction; Multi-Component Mooring Line; Attachments for Lines at the Platform End; Laying Out the Mooring System.