DNV—GL — COLUMN—STABILISED UNITS

The DNV GP RP, i.e. recommended practice, devoted to the column stabilised, or semi-submersible, mobile offshore drilling units. It is presenting the recommendations applicable to the strength analysis of the main structural members of these units. The methods that are outlines in the present document have been mainly developed for the analyses or ring pontoon- and twin pontoon semi-submersible units.

This should be taken into consideration as necessary. The RP starts with the general information section where the design principles and parameters are addressed including design conditions and limit states and where important concept differences are explained. The next section is dealing with the environmental loads and conditions, covering both regular and irregular wave parameters, wave theory, wave loads and all other aspects involved.

The rest of the sections cover the design loads including accidental and deformation loads and sea and tank pressures, global response analysis, global structural model, local structural analysis including damaged structure and superimposing responses, strength criteria. In addition, the document covers support of the mooring equipment , transit conditions etc.