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 crane housing having a substantially cylinder-shaped circumferential wall with a lower section and lower end mounted to a slew bearing of substantially the same diameter includes a boom support structure to support an inner end of a pivotal boom arranged at a front side of the crane housing. The boom support structure includes at least two box elements of each of which an end portion overlaps with and is integrated with the upper section of the circumferential wall. Oblique strengthening ribs are mounted onto and integrated with a side of the circumferential wall and extend from a respective box element end portion in an oblique downwards direction towards the lower end of the wall.

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.

Methods and apparatus for deploying a plurality of unmanned marine vehicles into water, in which each unmanned marine vehicle including a float and a glider connected by a tether. A buoyant platform carries the plurality of unmanned marine vehicles is advanced through the water. Each respective unmanned marine vehicle is secured in an associated apparatus comprising a buoyant frame defining a receiving bay, a float clamp assembly coupled to the buoyant frame and selectively retaining a float of the respective unmanned marine vehicle in the receiving bay, and a glider retainer assembly configured to selectively hold the glider of the respective unmanned marine vehicle below the buoyant frame. Each respective unmanned marine vehicle and associated apparatus is transferred from the buoyant platform to the water, and each respective unmanned marine vehicle is deployed from the associated apparatus.

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.

Disclosed is a method and apparatus for transferring cargo having a cavity therein, the system comprising: (a) a lifter suspended in free floating form by a crane; (b) the lifter having a frame and at least one lifting arm which is detachably connected to the frame; and wherein the frame has at least one lifting connector for detachably connecting the lifter to the crane.

A crane housing having a substantially cylinder-shaped circumferential wall with a lower section and lower end mounted to a slew bearing of substantially the same diameter includes a boom support structure to support an inner end of a pivotal boom arranged at a front side of the crane housing. The boom support structure includes at least two box elements of each of which an end portion overlaps with and is integrated with the upper section of the circumferential wall. Oblique strengthening ribs are mounted onto and integrated with a side of the circumferential wall and extend from a respective box element end portion in an oblique downwards direction towards the lower end of the wall.

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 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 be 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.

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).