Disclosed is a root clamping plate for a transportation system and a transportation system configured for transportation of a wind turbine. The root clamping plate comprising: a plurality of bolt holes and a resting face configured to engage with a receiver of a main root frame. The root clamping plate being configured to engage with a first element configured for a first transportation type, and the root clamping plate being configured to engage with a second element of a second transportation type.

A multiple rotor (MR) wind turbine comprising a tower (21) extending in an upwards direction, a load carrying structure (22) extending in an outwards direction and being fixed to the tower, and an energy generating unit (54) fixed to the load carrying structure, wherein the outwards direction is transverse to the upwards direction, the wind turbine further comprising a hoisting line (53) for communication of objects (52) to and from the energy generating unit (54), the hoisting line being windable from an attachment point (55) of the load carrying structure or from the energy generating unit. To allow positioning of hosted objects near the tower, or at selectable distance from the tower, the hoisting line extends from the attachment point via a suspension point (56) to a lifting point (57) where the object (52) can be attached, and the suspension point (56) is movable outside the load carrying structure.

A method of handling the pitch bearing unit of a rotor blade mounted to the hub of a wind turbine, the method including the steps of providing an extension assembly at the interface between the rotor blade and the hub, moving the rotor blade outward from the hub by means of the extension assembly to open a gap large enough to accommodate the pitch bearing unit while maintaining a connection between the rotor blade and the hub, and removing the pitch bearing unit through the gap.

A method for assembling a wind turbine, including: attaching an elevator carriage (27) to a nacelle (9) to form a carriage-nacelle assembly (27,9); and mounting the carriage-nacelle assembly (27,9) on to a tower (3) as a unit.

Described is a tool and apparatus for positioning a blade for a wind turbine the wind turbine including a tower and a rotatable hub on the tower. The tool is mounted on a side of the tower so that the blade is supported on the tower in an initial configuration. The tool includes a first part arranged to be angularly movable relative to a second part for tilting the blade with respect to the tower to position the blade in a position that can allow the blade to be connected to the hub.

A safety door assembly for a hoist window of a structure includes a sliding door arranged to reveal or conceal the hoist window; and a barrier assembly which is closed to inhibit access to an area in front of the hoist window or opened to permit access to the area in front of the hoist window; and wherein the barrier assembly is adapted to prevent the sliding door from revealing the hoist window when the barrier assembly is open; and the sliding door is adapted to prevent opening of the closed barrier assembly when the sliding door reveals the hoist window.

The offshore jack-up has a hull and a plurality of moveable legs engageable with the seafloor. The offshore jack-up is arranged to move the legs with respect to the hull to position the hull out of the water. The method comprises moving at least a portion of a vessel underneath the hull of the offshore jack-up or within a cut-out of the hull when the hull is positioned out of the water and the legs engage the seafloor. A stabilizing mechanism mounted on the jack-up is engaged against the vessel. The stabilizing mechanism is pushed down on the vessel to increase the buoyant force acting on the vessel.

A method for mounting rotor blades of a wind turbine is provided. The wind turbine has a rotor hub with three rotor blade ports. A rotor blade is to be mounted to each of the three rotor blade ports. A mounting arm is fastened to a first rotor blade port. The mounting arm has a first section and a second section, which are coupled with each other via a hinge, so that the angle between the first and second sections can be varied. The hub is turned until the first rotor blade port is in a 90° position. A first end of the first section of the mounting arm is fastened to the first rotor blade port of the rotor hub. The rotor hub is turned with the help of the mounting arm, until the second rotor blade port is in a 270° position. The angle between the first and second sections of the mounting arm is varied while turning the rotor hub. A first rotor blade is lifted, so that the first rotor blade is horizontally mounted to the second rotor blade port of the rotor hub.

A method (100) of mounting a blade (22) to or unmounting a blade (22) from a rotor hub (20) of a wind turbine (10), the wind turbine (10) comprising a tower (12) and a nacelle (16) mounted on the tower (12), the rotor hub (20) being coupled to the nacelle (16), the method (100) comprising gripping the blade (22) using a gripper (50), the gripper (50) comprising gripping members (58) configured for gripping the blade (22) and teeth (60) protruding from the gripping members (58), wherein gripping comprises inserting the teeth (60) of the gripper (50) into receptacles (78) of the blade (22); and rotating the blade (22) about a rotation axis (54) perpendicular to a longitudinal blade axis (53) using a blade rotation device (52) of the gripper (50), wherein the teeth (60) are configured for transmitting an axial load (57) of the blade (22) between the blade (22) and the gripping members (58).

A handling arrangement for handling a wind turbine rotor blade includes a frame assembly realized to fit about the airfoil of the rotor blade; a number of add-on covers arranged to fit between the frame assembly and the airfoil surface, wherein an add-on cover is shaped to fit around a number of add-ons; and a load-bearing material for filling the add-on cover when the add-on cover is pressed against the rotor blade. A method of handling a wind turbine rotor blade is also provided.