Guide for Building and Classing Floating Offshore Wind Turbine Installations GUIDE FOR BUILDING AND CLASSING FLOATING OFFSHORE WIND TURBINE INSTALLATIONS JANUARY 2013 (Updated July 2014 – see next page) American Bureau of Shipping Incorporated by Act of Legislature of the State of New York 1862 Copyright 2013 American Bureau of Shipping ABS Plaza 16855 Northchase Drive Houston, TX 77060 USA Updates July 2014 consolidation includes: • January 2013 version plus Corrigenda/Editorials Foreword Foreword This Guide provides criteria for the design, construction, installation and survey of permanently sited Floating Offshore Wind Turbine Installations. It addresses three principal areas: the Floating Support Structure, the stationkeeping system, and onboard machinery, equipment and systems that are not part of the turbine Rotor-Nacelle Assembly (RNA). The criteria applicable to bottom-founded offshore wind turbine support structures and foundations are provided in the ABS Guide for Building and Classing Bottom-Founded Offshore Wind Turbine Installations. Requirements for ancillary offshore wind farm installations such as meteorological measuring towers, accommodation units, and transformer platforms are not addressed in this Guide. For the requirements for bottom-founded ancillary offshore wind farm installations, refer to the ABS Rules for Building and Classing Offshore Installations. The requirements applicable to floating ancillary offshore wind farm installations are provided in the ABS Guide for Building and Classing Mobile Offshore Units and the ABS Rules for Building and Classing Floating Production Installations. This Guide becomes effective on 15 January 2013. Users are advised to check periodically on the ABS website www.eagle.org to verify that this version of this Guide is the most current. We welcome your feedback. Comments or suggestions can be sent electronically by email to [email protected]. ABS GUIDE FOR BUILDING AND CLASSING FLOATING OFFSHORE WIND TURBINE INSTALLATIONS . 2013 iii Table of Contents GUIDE FOR BUILDING AND CLASSING FLOATING OFFSHORE WIND TURBINE INSTALLATIONS CONTENTS CHAPTER 1 Conditions of Classification .................................................................. 1 Section 1 Scope and Conditions of Classification ................................. 2 CHAPTER 2 Materials and Welding .......................................................................... 16 Section 1 General ................................................................................ 17 CHAPTER 3 General Design Requirements ............................................................ 18 Section 1 Design Considerations ......................................................... 19 CHAPTER 4 Environmental Conditions ................................................................... 23 Section 1 Overview .............................................................................. 25 Section 2 Wind ..................................................................................... 26 Section 3 Waves .................................................................................. 33 Section 4 Currents ............................................................................... 35 Section 5 Tides, Storm Surges, and Water Levels .............................. 37 Section 6 Other Conditions .................................................................. 49 CHAPTER 5 Loads ..................................................................................................... 41 Section 1 Overview .............................................................................. 42 Section 2 Design Load Conditions ....................................................... 44 Section 3 Determination of Environmental Loads ................................ 53 CHAPTER 6 Global Performance Analysis .............................................................. 58 Section 1 General Requirements ......................................................... 59 Section 2 Analysis Methodologies ....................................................... 62 CHAPTER 7 Design of Floating Support Structures ............................................... 64 Section 1 General Requirements ......................................................... 66 Section 2 Steel Structures ................................................................... 68 Section 3 Concrete Structures ............................................................. 76 iv ABS GUIDE FOR BUILDING AND CLASSING FLOATING OFFSHORE WIND TURBINE INSTALLATIONS . 2013 CHAPTER 8 Design of Stationkeeping Systems..................................................... 77 Section 1 General ................................................................................ 79 Section 2 Design Conditions ................................................................ 81 Section 3 Steel Mooring and Tendon Systems .................................... 83 Section 4 Synthetic Fiber Ropes .......................................................... 86 Section 5 Anchor Holding Power ......................................................... 87 Section 6 Field Test ............................................................................. 90 CHAPTER 9 Stability and Watertight/Weathertight Integrity ................................. 91 Section 1 General ................................................................................ 92 Section 2 Stability ................................................................................ 93 Section 3 Watertight/Weathertight Integrity ....................................... 101 CHAPTER 10 Machinery and Systems .................................................................... 102 Section 1 Design Requirements ........................................................ 103 CHAPTER 11 Surveys ............................................................................................... 105 Section 1 Surveys During Construction, Installation and Commissioning .................................................................. 107 Section 2 Surveys After Installation and Commissioning .................. 114 Section 3 Risk-based Surveys for Maintenance of Class .................. 119 ABS GUIDE FOR BUILDING AND CLASSING FLOATING OFFSHORE WIND TURBINE INSTALLATIONS . 2013 v This Page Intentionally Left Blank Chapter 1: Conditions of Classification CHAPTER 1 Conditions of Classification CONTENTS SECTION 1 Scope and Conditions of Classification ............................................... 2 1 Classification ....................................................................................... 2 3 Classification Boundaries .................................................................... 2 5 Classification Symbols and Notations ................................................. 2 5.1 Installations Built under ABS Survey ............................................... 2 5.3 Installations Not Built under ABS Survey ........................................ 2 7 Rules for Classification ....................................................................... 3 7.1 Application ....................................................................................... 3 7.3 References ...................................................................................... 3 7.5 Alternatives ...................................................................................... 3 9 Design Documentation to be Submitted ............................................. 3 9.1 Reports ............................................................................................ 4 9.3 Design Data and Calculations ......................................................... 5 9.5 Design Plans of Floating Support Structure ..................................... 6 9.7 Design Documentation of Stationkeeping System ........................... 7 9.9 Design Plans of Machinery and Systems ........................................ 7 9.11 Additional Plans ............................................................................... 8 11 Manuals and Procedures .................................................................... 9 11.1 Operating Manual ............................................................................ 9 11.3 Procedures .................................................................................... 10 13 Information Memorandum ................................................................. 10 15 Terms and Definitions ....................................................................... 11 15.1 Types of Floating Support Structures ............................................ 11 15.3 Terminology ................................................................................... 11 17 Abbreviations and References .......................................................... 14 17.1 Abbreviations of Organizations ...................................................... 14 17.3 References .................................................................................... 15 ABS GUIDE FOR BUILDING AND CLASSING FLOATING OFFSHORE WIND TURBINE INSTALLATIONS . 2013 1 Section 1: Scope and Conditions of Classification CHAPTER 1 Conditions of Classification SECTION 1 Scope and Conditions of Classification 1 Classification The general requirements for conditions of classification are contained in the ABS Rules for Conditions of Classification – Offshore Units and Structures (Part 1). Additional requirements specific to the Floating Offshore Wind Turbine Installation are contained in the following