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.

A slew bearing includes a stationary bearing ring to be fixed to a base, and a moveable bearing ring to be fixed to a moveable object, wherein the stationary bearing ring and the moveable bearing ring are configured to enable rotation of the moveable bearing ring relative to the stationary bearing ring about a rotation axis. A main axial bearing and an auxiliary bearing are provided between the stationary bearing ring and the moveable bearing ring, wherein the moveable bearing ring includes one or more main portions and one or more auxiliary portions, which one or more main portions are moveable relative to the one or more auxiliary portions between an operational position, in which the main axial bearing transfers the axial loads between moveable bearing ring and stationary bearing ring, and a raised maintenance position, in which the auxiliary axial bearing transfers the axial loads between moveable bearing ring and stationary bearing ring and the main bearing is allowed to be inspected and/or maintained so that the slew bearing during inspection and/or maintenance is still operational.

A hoisting crane or multi configurations crane system for use on an offshore vessel, such a vessel and methods for operating are disclosed. The hoisting crane comprises a boom having a proximal portion, an intermediate portion and a distal portion. An extension mechanism is provided that is configured to allow the distal portion to he slid relative to the intermediate portion from a retracted configuration to an extended configuration. In the retracted configuration, the intermediate portion is arranged substantially within the distal portion.

Disclosed is a method and apparatus for transferring a plurality of cargo units, each cargo unit having a cavity therein, providing a lifter suspended in free floating form by a crane, the lifter having a frame and at least one lifting arm which is detachably connected to the frame wherein the frame has at least one lifting connector for detachably connecting the lifter to the crane; moving the lifter to a position immediately adjacent the plurality of cargo units; causing each free end of the at least one lifting arm to penetrate at least one cavity of one of the plurality of cargo units; raising the at least one of the plurality of cargo units to an elevated position; moving the lifter and the at least one raised cargo unit to a second position laterally spaced from the original position wherein each free end of the at least one lifting arm is elevated compared to each second end of the at least one lifting arm; and depositing the raised cargo unit at the second position.

A vehicle crane having a superstructure with a jib system including a main jib mounted in a luffable manner on the superstructure, with a jib head and a luffable additional jib and at least one luffing support supported in the region of a luffing axis of the additional jib. At least one guying support of the jib system is arranged in such a manner that a tensioner starting on the one hand from the superstructure and/or from a counterweight and connected on the other hand to the additional jib is guided via the at least one guying support and the at least one luffing support. A main jib extension is incorporated between the jib head and the additional jib with the at least one guying support supported at the main jib extension to obtain a longer design of the jib system with the highest possible permissible bearing load.

A loading system for a material has a grab dredger configured to selectively engage the material, where the grab dredger includes a boom and a line configured to move a grab throughout a working space. The working space includes an arc within a plane defined by a first dimension and a second dimension, where a third dimension lies perpendicular to the plane. The working space includes a minimum engagement distance and a maximum engagement distance. A Light Detection and Ranging (LiDAR) module can locate a material acquisition point, a material deposit point, and at least one obstacle point. A controller operates the grab dredger to move the grab within the working space to selectively engage the material. The loading system can move the material from the material acquisition point to the material deposit point while negotiating the at least one obstacle point.

A marine knuckle boom crane includes a pedestal and a crane housing rotational relative to the pedestal. A knuckle boom assembly is attached to the crane housing and includes a main boom and a spreader type jib. A hoisting system includes a first departure sheave and a second departure sheave on the jib, and a third departure sheave mounted to the main boom or to the crane housing. One or more winches drive a first, second, and third cable which are each connected to an object suspension device and each pass via the first, second, and third departure sheave, respectively, to the respective winch. The first, the second, and the third cable together define an inverted pyramid which diverges upwards from the object suspension device when handling the object.

A hoisting arrangement for hoisting an offshore wind turbine blade, comprising a gripper attachment 150 arranged to be connected to the wind turbine blade, comprising a set of cable attachment points 191, 192,193 arranged as a first polygon, a vessel attachment module 194 arranged to be connected to a vessel, comprising a plurality of cable guide elements 190 arranged as a second polygon, a plurality of cables 141, 142, 143, 144 spanned between the cable attachment points and the cable guide elements, and a control system for controlling a position and/or orientation of the gripper attachment within a work space by controlling a spanned length of at least two cables of the plurality of cables between the cable attachment points and the cable guide elements.

Method and device (1) for lifting loads (7). An arm (2) that is the load or that supports a load (7) is pivotably connected to a reference. The load results in a torque. At least a part of the counter-torque to result in a system supporting the load is provided by a gas or hydro-pneumatic spring (60).

A hoisting crane for use on an offshore vessel, such a vessel and a method for hoisting an offshore wind turbine component wherein use is made of such a crane and/or vessel. The hoisting crane includes a base structure, a superstructure, a boom having a longitudinal axis and a length of 80-200 meters. The boom includes a proximal portion connected to the boom connection member, formed integral via a joint structure with a single distal leg, wherein the length of the distal leg between the joint and the boom head structure exceeds 30 meters.