EN 61400-3:2009

INTRODUCTION
1 Scope
2 Normative references
3 Terms and definitions
4 Symbols and abbreviated terms
   4.1 Symbols and units
   4.2 Abbreviations
5 Principal elements
   5.1 General
   5.2 Design methods
   5.3 Safety classes
   5.4 Quality assurance
   5.5 Rotor - nacelle assembly markings
6 External conditions
   6.1 General
   6.2 Wind turbine classes
   6.3 Wind conditions
   6.4 Marine conditions
   6.5 Other environmental conditions
   6.6 Electrical power network conditions
7 Structural design
   7.1 General
   7.2 Design methodology
   7.3 Loads
   7.4 Design situations and load cases
   7.5 Load and load effect calculations
   7.6 Ultimate limit state analysis
8 Control and protection system
9 Mechanical systems
10 Electrical system
11 Foundation design
12 Assessment of the external conditions at an offshore
   wind turbine site
   12.1 General
   12.2 The metocean database
   12.3 Assessment of wind conditions
   12.4 Assessment of waves
   12.5 Assessment of currents
   12.6 Assessment of water level, tides and storm surges
   12.7 Assessment of sea ice
   12.8 Assessment of marine growth
   12.9 Assessment of seabed movement and scour
   12.10 Assessment of wake effects from neighbouring wind
         turbines
   12.11 Assessment of other environmental conditions
   12.12 Assessment of earthquake conditions
   12.13 Assessment of weather windows and weather downtime
   12.14 Assessment of electrical network conditions
   12.15 Assessment of soil conditions
13 Assembly, installation and erection
   13.1 General
   13.2 Planning
   13.3 Installation conditions
   13.4 Site access
   13.5 Environmental conditions
   13.6 Documentation
   13.7 Receiving, handling and storage
   13.8 Foundation/anchor systems
   13.9 Assembly of offshore wind turbine
   13.10 Erection of offshore wind turbine
   13.11 Fasteners and attachments
   13.12 Cranes, hoists and lifting equipment
14 Commissioning, operation and maintenance
   14.1 General
   14.2 Design requirements for safe operation, inspection
         and maintenance
   14.3 Instructions concerning commissioning
   14.4 Operator's instruction manual
   14.5 Maintenance manual
Annex A (informative) - Key design parameters for an offshore
        wind turbine
Annex B (informative) - Wave spectrum formulations
Annex C (informative) - Shallow water hydrodynamics and breaking
        waves
Annex D (informative) - Guidance on calculation of hydrodynamic
        loads
Annex E (informative) - Recommendations for design of offshore
        wind turbine support structures with respect to ice loads
Annex F (informative) - Offshore wind turbine foundation design
Annex G (informative) - Statistical extrapolation of operational
        metocean parameters for ultimate strength analysis
Annex H (informative) - Corrosion protection
Bibliography
Annex ZA (normative) - Normative references to international
         publications with their corresponding European
         publications

IEC 61400-3:2009 specifies additional requirements for assessment of the external conditions at an offshore wind turbine site and specifies essential design requirements to ensure the engineering integrity of offshore wind turbines. Its purpose is to provide an appropriate level of protection against damage from all hazards during the planned lifetime. Focuses on the engineering integrity of the structural components of an offshore wind turbine but is also concerned with subsystems such as control and protection mechanisms, internal electrical systems and mechanical systems. It should be used together with the appropriate IEC and ISO standards, in particular with IEC 61400-1. This publication is to be read in conjunction with IEC 61400-1:2005.