A support tower, particularly for a wind turbine. The support tower has at least a first elongated component which is internally hollow and at least a second elongated component which is slidably coupled to the at least a first elongated component and movable relative to the at least a first elongated component at least between a retracted position. The second elongated component is at least partially inserted in the at least a first elongated component, and an extracted position, where the at least a second elongated component is substantially extracted from the at least a first elongated component. A moving device for moving the second elongated component from the retracted position to the extracted position, and vice versa, and a blocking device configured to allow the at least a second elongated component to be blocked in the extracted position, are also provided.

A method of building an offshore windmill includes, using a 3D-heave-compensated crane, placing on a windmill pedestal a lifting jack having a receiving region, and fixing the lifting jack to the windmill pedestal such that the lifting jack can be later removed, and such that a windmill column can be placed within the receiving region directly on the windmill pedestal. The windmill generator is installed using the 3D-heave-compensated crane. The windmill column is partially erected on the windmill pedestal using the 3D-heave-compensated crane and the lifting jack. Before the windmill is fully erected, windmill blades are placed on the windmill generator using the 3D-heave-compensated crane, and the erection of the windmill column on the windmill pedestal is completed using at least the lifting jack. Using the 3D-heave-compensated crane, the lifting jack is removed from the windmill pedestal.

A hoisting system for the at least one of an installation, a decommissioning and a maintenance of a wind turbine which comprises at least a foundation, a tower, a yawing part and a rotor of at least 80 m diameter with at least one blade, comprising a first hoisting device which comprises measures to establish a load carrying joint with an already built part of the wind turbine which is located above the foundation, wherein the hoisting system is characterized in that the ratio between the maximum hoist load of the hoisting device and the mass of the heaviest part is larger than 0.2 and smaller than 1 and in particular smaller than 0.8 and more in particular smaller than 0.7 and preferably smaller than 0.6, with the heaviest part being a heaviest part which is hoisted as one piece and which belongs to the yawing part of wind turbine.

A drilling rig includes a rig floor, first and second support structures, a mast, a lower drilling machine, a continuous drilling unit, an upper drilling machine, and an upper mast assembly. The rig floor includes a V-door defining a V-door axis extending perpendicularly from the side of the rig floor that includes the V-door. The first and second support structures define a traverse corridor having a traverse corridor axis, wherein the traverse corridor axis is perpendicular to the V-door axis. The drilling rig may be used for continuous drilling of a wellbore.

A mast assembly for a drilling rig includes a mast formed from a plurality of mast subunits. The mast assembly includes a lower drilling machine, upper drilling machine, and upper mud assembly, each of which is coupled to and movable vertically relative to the mast. The mast subunits are separable when the mast is in a transport configuration such that the LDM is positioned in a first subunit and the UDM is in a second subunit of the mast when the mast is in the transport configuration. The mast assembly may be used during a continuous drilling operation.

A tower for a wind turbine includes at least one tower section made of concrete, made up of several annular concrete segments arranged on top of one another with horizontal joints. Each concrete segment includes at least two annular segment prefabricated concrete parts arranged in parallel with vertical joints. The each have one outer side, one inner side and one upper, lower and two lateral contact faces. The concrete segments are connected to one another in the vertical direction by vertical clamping devices.

A connector element for a tubular mast assembly, a tubular mast assembly and a kit therefore, methods of assembling and disassembling, a guide device and a spreader are provided. In an aspect, a tubular mast assembly comprises first and second members each comprising a shell resiliently biased in the form of an elongate tube having longitudinal edges defining a slit along its length. A connector element comprising a first socket receives an end of the first member and a second socket receives an end of the second member so as to connect the first and second members into an extended tubular form. Each member can be disconnected from its socket and its shell opened out at the slit to assume a flattened form in which it can be wound into a coiled form for stowing the assembly.

A mast assembly that includes a mast and a hydraulic circuit for moving the mast. The hydraulic circuit includes a primary hydraulic cylinder coupled to the mast to rotate the mast about a pivot axis and a secondary hydraulic cylinder extending from a rod end to a cap end that is fluidly coupled to the primary hydraulic cylinder. A directional valve is fluidly coupled between the primary hydraulic cylinder and secondary hydraulic cylinder to keep a pressure on the cap end of the secondary hydraulic cylinder greater than the pressure on the rod end of the secondary hydraulic cylinder during all operating conditions.

A system for rotating a vessel may include a container assembly. An exemplary container assembly may include a head end frame that may be spaced apart from and interconnected with a tail end frame. An exemplary container assembly may be configured to encompass and hold the vessel or a portion of the vessel. An exemplary system for rotating a vessel may further include a linear actuating mechanism that may be coupled to a bottom edge of the tail end frame. An exemplary linear actuating mechanism may be configured to drive a translational movement of the bottom edge of the tail end frame along a first axis. An exemplary system for rotating a vessel may further include a double-pivot link that may be pivotally connected between a top edge of the head end frame and a fixed revolute joint. An exemplary double-pivot link may be configured to rotate the top edge about the fixed revolute joint responsive to the translational movement of the bottom edge of the tail end frame along the first axis.

The invention relates to a method of erecting a tower such as a wind turbine tower tethered by a number of cables where each of the cables extend between the tower and an anchoring element on an anchor block. The method comprises attaching at least some of the tethering cables to the tower, detachably fastening a motorized winch on an anchor block and connecting the wire of the winch to the end of a tethering cable. The winch is then operated to wind up the wire of the winch pulling the cable end towards the anchor block and into position for fastening the cable end to the anchoring element, where the cable end is then fastened to the anchoring element while held in position by the winch. The invention further relates to the use of a motorized winch to connect a cable to an anchor block when erecting a tower tethered by a number of cables as mentioned above.