Abstract: In the installation of a rotor blade in horizontal orientation to the hub of a horizontal axis offshore wind turbine, use is made of a blade motion synchronization and positioning device, which comprises a wind turbine coupler, a blade coupler, a motion arm between the wind turbine coupler and the blade coupler, and a controllable motion arm actuator assembly. The method includes bringing and maintaining the blade coupler in a motion compensated receiving position, wherein the arm is operated to compensate for sea state and/or wind induced tower top motion. In receiving position, the coupler is coupled to the blade that is suspended from a crane. The actuator assembly is then operated to gradually bring, and then maintain, the coupled blade in a horizontal motion that is synchronized with tower top motion, and to displace the coupled blade root into a pre-mounting position.

Abstract: A crane vessel for hoisting of an offshore wind turbine or a component thereof, includes a hull having a deck. A crane configured for hoisting of an offshore wind turbine or a component thereof includes a vertical crane structure having a crane structure base fixed to the hull, the crane structure extending from the hull over a height thereof to a top along a vertical axis of the crane structure, a boom, and a slew bearing allowing to revolve the boom, about a slew axis. A main hoisting system includes at least one main hoisting winch, an associated main hoisting cable and a load connector, the main hoisting cable extending from the main hoisting winch to a main hoist cable guide on the boom and then to the load connector.

Abstract: In the installation of a rotor blade in horizontal orientation to the hub of a horizontal axis offshore wind turbine, use is made of a blade motion synchronization and positioning device, which comprises a wind turbine coupler, a blade coupler, a motion arm between the wind turbine coupler and the blade coupler, and a controllable motion arm actuator assembly. The method includes bringing and maintaining the blade coupler in a motion compensated receiving position, wherein the arm is operated to compensate for sea state and/or wind induced tower top motion. In receiving position, the coupler is coupled to the blade that is suspended from a crane. The actuator assembly is then operated to gradually bring, and then maintain, the coupled blade in a horizontal motion that is synchronized with tower top motion, and to displace the coupled blade root into a pre-mounting position.

Abstract: A stabbing guide for tubulars, including a body; a plurality of guide members moveably supported by the body to receive a tubular and to move relative to the body between an open position and a closed position; and an actuation mechanism configured to be operated to move the plurality of guide members between the open and closed positions, wherein the body is configured to be held by a tubular connection tool.

Abstract: In a method for installing a blade on a horizontal axis rotational hub of an offshore wind turbine, use is made of a blade installation device that is temporarily installed on the offshore wind turbine. The device includes a mounting part that is mounted on the foundation of the offshore wind turbine and/or on a lower portion of the wind turbine mast. A guide mast having a track is supported by the mounting part and extends parallel and adjacent to the wind turbine mast. A support bracket laterally supports the guide mast. The blade installation device further includes a blade manipulator assembly with a trolley that is movable along the track and a blade manipulator including blade engagement members. The blade manipulator is supported by the trolley via an actuating assembly including actuators. A positioning system controls the actuators.

Abstract: In a method for installing a blade on a horizontal axis rotational hub of an offshore wind turbine, use is made of a blade installation device that is temporarily installed on the offshore wind turbine. The device includes a mounting part that is mounted on the foundation of the offshore wind turbine and/or on a lower portion of the wind turbine mast. A guide mast having a track is supported by the mounting part and extends parallel and adjacent to the wind turbine mast. A support bracket laterally supports the guide mast. The blade installation device further includes a blade manipulator assembly with a trolley that is movable along the track and a blade manipulator including blade engagement members. The blade manipulator is supported by the trolley via an actuating assembly including actuators. A positioning system controls the actuators.

Abstract: A crane vessel for hoisting of an offshore wind turbine or a component thereof, includes a hull having a deck. A crane configured for hoisting of an offshore wind turbine or a component thereof includes a vertical crane structure having a crane structure base fixed to the hull, the crane structure extending from the hull over a height thereof to a top along a vertical axis of the crane structure, a boom, and a slew bearing allowing to revolve the boom, about a slew axis. A main hoisting system includes at least one main hoisting winch, an associated main hoisting cable and a load connector, the main hoisting cable extending from the main hoisting winch to a main hoist cable guide on the boom and then to the load connector.

Abstract: A stabbing guide for tubulars, including a body; a plurality of guide members moveably supported by the body to receive a tubular and to move relative to the body between an open position and a closed position; and an actuation mechanism configured to be operated to move the plurality of guide members between the open and closed positions, wherein the body is configured to be held by a tubular connection tool.

Abstract: A semi-submersible floating offshore vessel has a deckbox structure with a main deckbox bottom extending underneath a lower deck. The deckbox structure includes a recessed cellar deck structure that protrudes below the main deckbox bottom, which recessed cellar deck structure has a cellar deck bottom wall that is closed and wave impact resistant and which recessed cellar deck structure has a peripheral wall that is closed and wave impact resistant. The peripheral wall extends between an outer perimeter of the cellar deck bottom wall and the main deckbox bottom of the deckbox structure. The moonpool extends through the recessed cellar deck structure. Seen in plan view, the recessed cellar deck structure includes a number of pointed wave crest splitting sections.

Abstract: A wave-induced motion compensation crane and corresponding vessel and method are disclosed. The crane includes a motion compensation device at a tip end portion of the boom structure to compensate for X-Y wave-induced motion and a heave compensation device for Z-motion. The motion compensation device includes a moveable jib beam that extends in a substantially horizontal direction. The jib beam is slewable about a substantially vertical slew axis and translatable in a longitudinal direction of the jib beam. Preferably, the jib beam can be levelled based on the angular orientation of the boom structure.

Abstract: A wave-induced motion compensation crane and corresponding vessel and method are disclosed. The crane includes a motion compensation device at a tip end portion of the boom structure to compensate for X-Y wave-induced motion and a heave compensation device for Z-motion. The motion compensation device includes a moveable jib beam that extends in a substantially horizontal direction. The jib beam is slewable about a substantially vertical slew axis and translatable in a longitudinal direction of the jib beam. Preferably, the jib beam can be levelled based on the angular orientation of the boom structure.