Maritime

DNV rules and standards for offshore units - July 2023 edition

The July 2023 edition of the DNV rules and standards for classification of offshore units has now been published.

DNV rules update - July 2021

Six updated offshore rule documents (RU-OU), as well as six revisions of offshore standards (OS), were formally approved on June 14th by Group CEO Remi Eriksen. The updates include new and revised class notations, implementation of IACS and IMO requirements, and general improvements.

The 2023 edition will enter into force for class application on 1st January 2024.

DNV publishes one main rule edition every year. The next main rule edition is scheduled to be published in July 2024. From time to time, additional amendments may be made to the rules. These amendments will be announced in the Rules and Standards Explorer

The main changes in this edition include: 

  • Update and change of name of DNV-RU-OU-0512 from Floating offshore wind turbine installations to Floating wind installations.
  • New service notation Substation installation, expanding the installation types covered by DNV-RU-OU-0512.
  • New additional class notation HV for high voltage facilities on a floating substation, i.e. the electrical transformer and transmission system on board.
  • Update of DNV-RU-OU-0571 Floating infrastructure installations to include the new additional class notations HAB for the accommodation on board and Cyber secure.
  • Major update and change of name of DNV-OS-C101 from Design of offshore steel structures, general - LRFD method to Structural design of offshore units. DNV-OS-C101 now includes both LFRD and WSD methods, and DNV-OS-C201 is retired.
  • New or updated additional class notations CCS for carbon capture and storage on production units, EXT for life extension on FPSO’s, Abate(P+) for substantial reductions in emissions from power generation.

A detailed description of the changes to the individual documents can be found in the ‘Changes – current’ table in each document.  The updated documents are: 

Offshore units rules: 

  • DNV-RU-OU-0101 Offshore drilling and support units
  • DNV-RU-OU-0102 Floating production, storage and loading units
  • DNV-RU-OU-0103 Floating LNG/LPG production, storage and loading units
  • DNV-RU-OU-0104 Self-elevating units, including wind turbine installation units and liftboats
  • DNV-RU-OU-0512 Floating wind installations
  • DNV-RU-OU-0571 Floating infrastructure installations
Offshore standards: 
  • DNV-OS-B101 Metallic materials
  • DNV-OS-C101 Structural design of offshore units
  • DNV-OS-C401 Fabrication and testing of offshore structures
  • DNV-OS-D202 Automation, safety and telecommunication systems
  • DNV-OS-E304 Offshore mooring steel wire ropes
  • DNV-OS-E403 Offshore loading and infrastructure buoys

Customers can contact their local DNV office for more information on the changes.


Oslo, Norway, 2023-06-29
Axel Stang Lund
Service Responsible – Offshore Class
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