Method and device for connecting a blade of a wind turbine to a hub

Abstract

The present invention relates to a blade positioning system configured for positioning wind turbine blades at a hub of a nacelle of a wind turbine from an installation vessel at an offshore location, the blade positioning system comprising: the installation vessel comprising: —at least one lifting device configured for lifting wind turbine components, and —an auxiliary support tower extending upwardly from the installation vessel, the auxiliary support tower comprising: o a nacelle support for supporting the nacelle, o a root end moving assembly defining a guide path which extends over a vertical distance, the root end moving assembly comprising a movable root end support base and a root end support configured for supporting and guiding the root end of the blade, the root end support being connected to the movable root end support base, the root end support being movable along the guide path, the root end moving assembly being configured for moving the root end of the blade along the guide path from the engagement position to an installation position, the at least one lifting device being configured for lifting the nacelle onto the auxiliary support tower, wherein the at least one lifting device and the root end moving assembly are configured to jointly support and jointly move the blade upwards towards the hub, wherein during the movement the root end is supported by the root end support and the lifting device carries a majority of the vertical loads on the blade.