A lifting unit includes a jib foot forming a proximal part of a jib in a service configuration, a counter jib supporting a balancing ballast, a securing part between the jib foot and the counter jib to secure the lifting unit to a mast, and a cylinder connected to the jib foot such that the jib foot is movable between a lowered position and a lifted position. A second cylinder is connected to the securing part.

Disclosed is a technique of executing: a fixing step of coupling a pulling-raising rope 171 to a vicinity of a distal end 73 of a strut 70; a first raising step of pulling the pulling-raising rope 171 rearwardly to cause a swingable portion 78 of the strut 70 to swing upwardly and rearwardly; a second raising step of pulling the pulling-raising rope 171 rearwardly until a strut body portion 76 has a rearwardly inclined posture with respect to a vertical direction; a strut returning step of pulling a pulling-returning rope 23a forwardly to a position where a forward swinging movement of the swingable portion 78 with respect to the strut body portion 76 is restricted; and a coupling step of coupling the swingable portion 78 and the strut body portion 76 to each other in a non-swingable manner.

A crane includes: a boom; a jib; a front post that is swingably attached to a tip end side of the boom; a rear post that is swingably attached to the tip end side of the boom; a post-side pendant member, with one end of the post-side pendant member being attached to a tip end of the rear post; a boom-side pendant member, with one end of the boom-side pendant member being attached to another end of the post-side pendant member, and another end of the boom-side pendant member being attached to the boom; and a post driving device having a link mechanism that rotates the rear post in a range including a position at which the rear post is swung down to the front post side and a position at which the rear post is swung down to the boom side, while the boom is held down in a horizontal position.

The self-hoisting crane is adapted to be hoisted from a container to a nacelle by operating a cable winch in the container, at least one cable is adapted to extend from the cable winch, around an exit sheave arranged in the container, and exit the container from the exit sheave in an upward direction in order to pass around at least one roller arranged at a crane base on the nacelle and continue in a downward direction to the crane, enter through a central opening in the crane pedestal and continue to the hook block. The exit sheave is located at a longitudinal position of the container deviating not more than 10 percent of the length of the container from the longitudinal position of the centre of gravity of the container.

The self-hoisting crane is adapted to be hoisted from a container to a nacelle by operating a cable winch in the container, at least one cable is adapted to extend from the cable winch, around an exit sheave arranged in the container, and exit the container from the exit sheave in an upward direction in order to pass around at least one roller arranged at a crane base on the nacelle and continue in a downward direction to the crane, enter through a central opening in the crane pedestal and continue to the hook block. The exit sheave is located at a longitudinal position of the container deviating not more than 10 percent of the length of the container from the longitudinal position of the centre of gravity of the container.

A self-climbing tower crane includes a crane base configured to be placed on a support at a hoisting site, tower segments to erect a crane tower, a crane tower lifting unit mounted on the crane base, and a slewable jib unit. The tower crane is configured to, with the slewable jib unit connected to an upper tower segment, erect the crane tower by stacking tower segments onto one another from below to lengthen the crane tower under the slewable jib unit. The crane tower includes an upper section to be composed of a series of multiple upper tower segments and a lower section to be composed of a series of multiple lower tower segments. Each upper tower segment is embodied as a tubular girder type tower segment. Each lower tower segment is embodied as a latticed structure type tower segment. The tower crane further includes an upper stabilizer device and a lower stabilizer device, each configured to horizontally connect the upper section of the crane tower to an external tall structure, e.g. a wind turbine mast.

Provided is an assembly method for a crane, by which method a crane including a strut can be assembled easily. The assembly method for the crane includes a strut coupling step of coupling a base end of a strut, a cylinder connecting step of extending a cylinder unit having one end supported by the strut, the cylinder unit being capable of extending/contracting, to connect the other end of the cylinder unit to the boom, a strut raising step of causing the cylinder unit to contract to raise the strut, and a strut supporting step of stretching a stretching member, such as a rear side guy line or a luffing cable, between a front end of the strut and a base end of the boom to support the strut in a raised state.

The present invention concerns a lifting apparatus, in particular a cross lifting beam, for lifting a first pylon segment of a concrete pylon of a wind power installation by means of a crane, including at least one fixing means for fixing the pylon segment to the lifting apparatus, and at least one release apparatus for releasing a connection between the lifting apparatus and the pylon segment.

A wind turbine (1) has three wind turbine blades (6.sub.1, 6.sub.2, 6.sub.3), each being arranged rotatably on the rotor hub (5) about a pitch axis in order to adjust a pitch angle of the wind turbine blade. Before performing the service work, a pitch angle adjustment is performed so that a pitch angle difference between respective pitch angles of two of the wind turbine blades is between 45 degrees and 135 degrees or between 225 degrees and 315 degrees. After performing the service work, a pitch angle adjustment is performed so that there is at least substantially no pitch angle difference between pitch angles of the respective wind turbine blades of the rotor (4). During the service work, the rotor is maintained in a rotational position in which a longitudinal axis of the third wind turbine blade forms an angle of not more than 5 degrees with a horizontal axis.

A tower crane for performing a lifting a load includes an extendable tower assembly having a central axis and including a plurality of separate tower sections, a climbing assembly including a climbing frame positioned on the tower assembly and a latching assembly to transport the climbing assembly vertically along the tower assembly, and a boom assembly atop the tower assembly and including a crane floor, a boom supported on the crane floor, a lifting member coupled to the boom, and a slew bearing coupled to the crane floor and configured to permit the crane floor to rotate about a rotational axis, wherein the slew bearing includes a first bearing position and a second bearing position spaced from the first bearing position relative to the central axis of the tower assembly.