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 securing the vessel with respect to the hull of the offshore jack-up when the hull is positioned out of the water and the legs engage the seafloor. A lifting mechanism mounted on the offshore jack-up engages with a cargo carrying platform positioned on the vessel. The platform is lifted with the lifting mechanism between a first position on the vessel and a second position clear of the vessel.

Tower erecting systems and methods are disclosed. An example method for erecting a tower includes: nesting frusto-conical tower sections within one another and within a frusto-conical tower base; securing the frusto-conical tower base to a tower foundation; lifting each frusto-conical tower section from within the frusto-conical tower base with a lifting apparatus; and securing each frusto-conical tower section to the frusto-conical tower base or to a previously lifted frusto-conical tower section.

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.

A method of performing maintenance on a wind turbine component (18, 22, 24) of a wind turbine (10) having an integrated lifting apparatus (40). The method includes lifting a first temporary support (104) using the integrated lifting apparatus (40), coupling the first temporary support (104) to the nacelle (12) or the hub (16) and the integrated lifting apparatus (40), removing the wind turbine component (18, 22, 24) using the integrated lifting apparatus (40) and the first temporary support (104) in combination. The method may further include installing a replacement wind turbine component (18, 22, 24) using at least a part of the integrated lifting apparatus (40) and the first temporary support (104) in combination, decoupling the first temporary support (104) from the nacelle (12) or the hub (16) and the integrated lifting apparatus (40), and removing the first temporary support (104) from the wind turbine (10) using the integrated lifting apparatus (40). A system for performing maintenance on a wind turbine component (18, 22, 24) is also disclosed.

A lift system mountable in a nacelle of a wind turbine has a boom having a proximal end mountable in the nacelle and a distal end extending over a hub of a rotor of the wind turbine when the lift system is mounted in the nacelle. The lift system has a frame structure for mounting the proximal end of the boom in the nacelle, a winch mounted to the boom, a fastener situated below the boom and operatively connected to the winch by at least one cable, and a trolley movably mounted to the boom to permit translation of the trolley longitudinally along the boom thereby permitting longitudinal movement of the fastener with respect to the boom.

Provided is a lifting tool for lifting a wind turbine blade by means of a crane for subsequent assembly with a wind turbine, the lifting tool having at least one attachment means for attachment to the crane and at least one holding device for holding the wind turbine blade, whereby the at least one holding device is connected to a controller of the lifting tool and the holding device includes at least one movable supporting element for supporting the wind turbine blade and at least one actuator connected to the at least one movable supporting element and controlled by the controller so that the movable supporting element is movable by means of the actuator. Further provided is a lifting arrangement, a wind turbine installation environment and a method for assembling a wind turbine blade with a hub of a wind turbine.

A crane includes a crane structure defining a substantially vertical rotation axis; a boom connected with a first end to the crane structure to be rotatable about the vertical rotation axis; a trolley moveable along the boom in longitudinal direction of the boom; a hoisting cable and a load connector. The load connector is arranged at a free end of the hoisting cable to be connected to a load for hoisting purposes. The trolley includes a cable guide to guide the hoisting cable and an attachment configured to temporarily attach the load connector to the trolley to fix the position of the load connector relative to the trolley.

Disclosed are tower erection systems and tower climbing systems and associated methods of operation. A tower erection system, in accordance with various embodiments, includes a ground-installed lifting structure, and a lifting frame configured to latch onto individual tower sections and traveling vertically inside the ground-installed lifting structure, lifted by a winch-and-cable or other lifting mechanism. Using this system, a tower may be assembled from multiple sections from the top down. A tower climbing system, in accordance with various embodiments, includes upper and lower climbers that can latch onto the lateral surface of a tower and a lifting mechanism that can move the climbers vertically relative to each other. The system can be used to carry a crane or other heavy equipment up and down along the tower. A climbing crane may be used, for example, during tower construction, or to reach the top of the tower for maintenance or repair.

The present invention relates to a lifting assembly (1) for elevating components to a wind turbine (5). The lifting assembly comprises a plurality of tower segments (13) which together form an elongated tower (9), a support frame (11) for supporting the tower (9), a securing assembly (32) securing the tower (9) to the wind turbine (5). The lifting assembly (1) further comprises an upper platform (7) provided with and a crane (21) and vertically movable along the tower (9), and a lower platform (8) provided with a storage area (16) for supporting components and vertically movable along the tower (9) between the upper platform (7) and the support frame (11). The crane is adapted to move components to and from the storage area (16) of the lower platform (8).

The invention relates to a crane as a component of a wind farm installation vessel which consists of a vessel body and a plurality of jack-up legs arranged in vertically movable manner thereon, wherein the crane is arranged rotatably about one of the jack-up legs. According to the invention, the crane is rotatably mounted on an eccentric platform which itself is arranged rotatably about the jack-up leg.