DNV DNV-ST-0119 PDF

This standard gives requirements for the following:

— design principles

— design loads

— load effect analyses

— load combinations

— selection of materials and extent of inspection in manufacturing yard

— structural design

— station keeping

— anchoring

— floating stability

— corrosion protection

— transport and installation

— in-service inspection

— power cable design.

This standard specifies requirements for the design of floating wind turbine structures intended to ensure a safety level that is deemed acceptable for such structures. Some of these requirements imply certain constraints on structural designs that reflect the current practice in the industry and established principles of design and construction of floating structures. Alternative designs and arrangements that deviate from these requirements may be accepted provided that it is documented that the level of safety is at least as high as that implied by the requirements of this standard. A basic premise for such analyses should be that all cost effective risk control options have been implemented. Technology qualification procedures may be helpful in this context.

A recommended method for identifying risk control options and documenting the safety of alternative designs and arrangements is given in DNV-RP-A203.

Guidance note:

Risk acceptance criteria may be taken in accordance with IMO MSC-MEPC.2/Circ.12 .

The specific requirements of this standard reflect what was deemed cost effective means of managing the risks associated with floating wind turbine structures at the time of issue of this standard. Technology developments after that point in time may provide new means of cost effective risk reduction. Should relevant cost benefit assessment show that use of such new technology would provide cost effective risk reduction, such new technology should be implemented on new floating structures where it fits.