The present invention relates to a method for installing a wind turbine or other tall structure at a target location at sea, the method comprising: —providing an installation vessel comprising at least one crane, wherein the crane comprises a lower boom part, a right boom part, and a left boom part, wherein the right boom part and the left boom part are connected to an upper portion of the lower boom part and extend from said upper portion, wherein a space is present between the right and left boom part, —lifting a tall structure part, in particular the nacelle assembly, with the crane, wherein in top view the tall structure part is supported at least partially between the right and left boom part by one or more hoist lines extending from the right and left boom part to the tall structure part.

The present invention relates to a method for installing a wind turbine or other tall structure at a target location at sea, the method comprising: —providing an installation vessel comprising at least one crane, wherein the crane comprises a lower boom part, a right boom part, and a left boom part, wherein the right boom part and the left boom part are connected to an upper portion of the lower boom part and extend from said upper portion, wherein a space is present between the right and left boom part, —lifting a tall structure part, in particular the nacelle assembly, with the crane, wherein in top view the tall structure part is supported at least partially between the right and left boom part by one or more hoist lines extending from the right and left boom part to the tall structure part.

The present invention relates to a process of producing a boom part from a sheet metal blank, in particular a process of producing a boom part having a bearing seat, in which the starting material is merely formed by bending. Thus, the production process is simplified. In addition, the present invention relates to a process of producing a boom that is closed at both ends by joining two boom parts produced by means of the process of the present invention. Furthermore, the present invention comprises boom parts and booms which are produced by means of one of the processes according to the present invention.

The present invention relates to a process of producing a boom part from a sheet metal blank, in particular a process of producing a boom part having a bearing seat, in which the starting material is merely formed by bending. Thus, the production process is simplified. In addition, the present invention relates to a process of producing a boom that is closed at both ends by joining two boom parts produced by means of the process of the present invention. Furthermore, the present invention comprises boom parts and booms which are produced by means of one of the processes according to the present invention.

The present disclosure includes a telescopic bearing assembly capable of withstanding predetermined bending loads and at the same time is fully telescopically extendable, while minimizing a wall thickness (t) in each of tubular bearing sections of an associated telescopic arm. Additionally, the present disclosure includes a mobile hydraulic telescopic crane with a telescopic arm with such an assembly.

The present disclosure refers to a mobile telescopic hydraulic crane, which may include at least one service opening in a terminal portion of a telescopic section adjacent to at least one hydraulic connector, wherein said at least one service opening is configured to allow access for a hand tool from the outside of the telescopic section to establish or disassemble a hydraulically sealed connection between a flexible hydraulic pipe and associated hydraulic connector within said telescopic arm. The at least one service opening allows for a quick and simple replacement of each hydraulic pipe within the telescopic secondary arm without significantly reducing the carrying capacity and reach of the crane.

A handling device (103) for loads (105) includes a radar transmitter (107), a radar sensor (111) and a data-processing device. The radar transmitter (107) is configured to irradiate at least part of the handling device (103) and/or the load (105). The radar sensor (111) is configured to detect at least part of the irradiated handling device (103) and/or the irradiated load (105). The data-processing device is configured to determine the position of at least part of the handling device (103) and/or the load 105) with reference to a signal from the radar sensor (111). At least a part (405) of the handling device (103) is radar-absorbing.

The invention relates to a method of manufacturing a tower (2) for an offshore wind turbine as well as such a tower. The method comprises providing the tower, mounting a crane (5) to an outer surface of the tower, and transporting the tower to the installation site of the wind turbine after the mounting of the crane. The crane comprises a base part (6) fixedly mounted to the tower, and a crane arm (7) pivotally connected to the base part at a first end (8). The method may further comprise a step of testing and certifying the crane according to a predetermined standard before the step of transporting the tower to the installation site. By application of the invention, the amount of installation work to be performed at the installation site can be minimized. In some embodiments of the invention, the crane arm has a shape matching the outer surface of the tower.

The invention relates to a method of manufacturing a tower (2) for an offshore wind turbine as well as such a tower. The method comprises providing the tower, mounting a crane (5) to an outer surface of the tower, and transporting the tower to the installation site of the wind turbine after the mounting of the crane. The crane comprises a base part (6) fixedly mounted to the tower, and a crane arm (7) pivotally connected to the base part at a first end (8). The method may further comprise a step of testing and certifying the crane according to a predetermined standard before the step of transporting the tower to the installation site. By application of the invention, the amount of installation work to be performed at the installation site can be minimized. In some embodiments of the invention, the crane arm has a shape matching the outer surface of the tower.

There is provided a crane including a main body, a tower derrickably supported by the main body, a jib derrickably supported by the tower, an assist member that assist the jib to move along a ground, and a determination unit that determines whether or not the jib is stopped when the tower is lowered in a lowering work state where the jib is assisted by the assist member.