N-001 Integrity of offshore structures (2020)

This NORSOK standard is the principal standard for offshore structures, and together with the normative standards in this document, it constitutes a common basis covering those aspects addressing design requirements, integrity management and assessment of all types of offshore structures. The standard especially refers to NS-EN ISO 19900, Petroleum and natural gas industries - General requirements for offshore structures and represent the full set of requirements valid for the NORSOK set of standards from NS-EN ISO 19900, in particular the partial safety factor method (also called the LRFD method) based requirements. Since this document is based on the same principles and requirements as NS-EN ISO 19900, NS-EN ISO 19900 may be treated as supplementary.

The 2020 edition of the document has undergone a major revision where the main changes since last edition are as follows:

The document has been restructured to make a more readable arrangement of the different sections.
Requirements have been rewritten to be in accordance with the NORSOK digitalization initiative.
Requirements have been substituted with references to updated NORSOK and ISO documents.
Introduced a section on design principles.
Robustness assessment have been modified to give clear requirements.
Requirements to nonlinear analysis have been adjusted.
Verification chapter has been restructured to provide clear requirements and recommendations.
Reliability based method is moved into a separate section.
The two steps in the ALS check is updated for clarity and to align with robustness definition.
Requirements to standards for materials and fabrication of steel, aluminium and concrete structures have been updated with latest revision of ISO and NORSOK M-standards.
Soil investigation and geotechnical design requirements have been substituted with ISO references.
Snow and ice actions for damaged case scenarios have been updated.
Stationkeeping requirements have been replaced with a reference to NS-EN ISO 19901-7 Annex B.2.
Section on subdivision, stability and freeboard has been rearranged and requirements earlier applicable only to the Norwegian Continental shelf are now made mandatory for structures designed according to this document.
Requirement to return period of environmental actions have been updated for ALS damaged condition.
A new section on “Facilities normally not manned” is introduced maintaining existing requirements and adding a new requirement regarding ALS check.
External underwater parts marking of floating units is included (moved from NORSOK N-005)
New requirement to air gap has been introduced.