IEC 61400-3-1:2019 outlines the minimum design requirements for fixed offshore wind turbines and is not intended for use as a complete design specification or instruction manual.Several different parties may be responsible for undertaking the various elements of the design, manufacture, assembly, installation, erection, commissioning, operation and maintenance of an offshore wind turbine and for ensuring that the requirements of this document are met. The division of responsibility between these parties is a contractual matter and is outside the scope of this document.This edition cancels and replaces the first edition of IEC 61400-3 published in 2009. This edition includes the following significant technical changes with respect to the first edition of IEC 61400-3:a) The design load table has been revised to simplify the approach to waves, both for several gust cases with the Normal Sea State, and for a number of cases with the Extreme Sea State. The guidance for load calculations has been altered accordingly;c) For load safety factors reference is now made directly to IEC 61400-1;d) Control system has been aligned with the latest updates in IEC 61400-1;e) Wave spectra has been replaced by a reference to ISO 19901-1;f) The annex on ice loading has been revised and updatedg) Two informative annexes concerning tropical cyclones have been introducedh) Other parts of the text have been aligned with IEC 61400-1