Abstract: A vessel with bridging means includes an upright column, a gangway, a first hinge connection for hingedly connecting the gangway to the column, coupling means at or near a free end of the gangway for coupling the gangway to an offshore construction, and one or more gangway support organs. The column is supported by and connected to the vessel by means of a second hinge connection designed to allow the vessel to rotate relative to the column in a first rotation direction around an x-axis and in a second rotation direction around an y-axis, wherein the x- and y-axes extend substantially horizontal and orthogonal relative to each other. Positioning means are provided which comprise force actuators between the vessel and the column for swiveling the column around the second hinge connection relative to the vessel around said x- and y-axis.

Abstract: A vessel with bridging means includes an upright column, a gangway, a first hinge connection for hingedly connecting the gangway to the column, coupling means at or near a free end of the gangway for coupling the gangway to an offshore construction, and one or more gangway support organs. The column is supported by and connected to the vessel by means of a second hinge connection designed to allow the vessel to rotate relative to the column in a first rotation direction around an x-axis and in a second rotation direction around an y-axis, wherein the x- and y-axes extend substantially horizontal and orthogonal relative to each other. Positioning means are provided which comprise force actuators between the vessel and the column for swivelling the column around the second hinge connection relative to the vessel around said x- and y-axis.

Abstract: A method for use with maintenance of an offshore wind farm includes a plurality of offshore wind turbines installed in open sea, where the method uses an assembly of a plurality of shuttle vessels 8, 9 and a seaworthy harbour ship 1 which includes an internal harbour basin 4 within outlines of the ship 1 and a plurality of mooring positions 7 for mooring the plurality of shuttle vessels 8, 9 to the ship 1 when lying inside the basin 4, where the method further includes comprises sailing the assembly of the plurality of shuttle vessels 8, 9 and the harbour ship 1 towards an anchoring position near or in the wind farm and anchoring the harbour ship 1 there, and sailing the plurality of shuttle vessels 8, 9 back and forth between the mooring positions 7 of the anchored harbour ship 1 and distinctive ones of the wind turbines for performing the maintenance thereto.