A method for retrofitting a wind turbine foundation is provided. The foundation comprises a first substantially elongated pile (31) in the ground. The method further comprises: arranging a lower end of an elongated channel (41) of a second substantially elongated pile (40) around the first pile (31), wherein the elongated channel (41) extends substantially along a longitudinal direction of the second pile (40), wherein the channel (41) is configured to receive at least a portion of the first pile. The method further comprises lowering the second pile (40) such that the elongated channel (41) surrounds at least a portion of the first pile (31). Finally, the second pile (40) is driven into the ground (35).

A wind turbine foundation comprising a concrete support slab having a horizontal rebar grid therein, a concrete pedestal integral with the support slab and having vertical post tensioning elements therein and a plurality of concrete ribs on top of and integral with the support slab and integral with the pedestal, the ribs having rebar therein and extend outwardly from the pedestal, the pedestal, slab and ribs are connected to each other to form a monolithic foundation. The foundation design reduces the weight and volume of materials used, reduces cost, and improves heat dissipation conditions during construction by having a small ratio of concrete mass to surface area thus eliminating the risk of thermal cracking due to heat of hydration.

Provided is a cable hang-off arrangement of an elevated platform including a number of tubular enclosures, wherein a tubular enclosure is configured to accommodate a transmission cable arrangement and includes a vertical section arranged for connection to a supporting structure of the elevated platform; a horizontal section arranged at the level of the elevated platform; and a curved section between the vertical section and the horizontal section. Also provided is a tubular enclosure of such a cable hang-off arrangement; an offshore facility; and a method of securing a transmission cable arrangement to such an offshore facility.

An assembly includes a first and a second section, where each section includes a longitudinal axis, and a fixation configured to fix the first and the second sections. At least one of the first and the second sections includes a body that is configured to be engaged by the fixation. The fixation includes an abutment and a displaceable actuator, and the actuator is radially displaceable.

An offshore structure having a foundation structure, wherein the foundation structure has at least a first and a second profile, the first profile is designed as a pile and the second profile is designed as a pile sleeve, the second profile encloses the first profile over a penetration length, wherein an interspace is formed between the first and the second profile, the interspace has a casting compound filling over the total penetration length, shear elements are provided on the first and/or the second profile, the shear elements extend into the interspace and effect an axial load dissipation into the casting compound filling, the shear elements are provided only over a first partial length of the penetration length, the first partial length is between 65 and 90% of the total penetration length and a second partial length is free of shear elements, wherein the second partial length forms the upper length of the penetration length in the installed position.

A wind turbine tower is supported on a transition piece that connects the tower to a foundation and that defines a space beneath the lower end of the tower. Electronic components positioned within a removable module in the lower portion of a wind turbine tower may be removed through a lower end of the tower for service or replacement.

A system and method for mating equipment offshore to a spar buoy secured to a foundation without the use of a crane barge. The system comprises a floating vessel having a pair of forks defining a slot. A gimbal table, defining an opening, is positioned within the slot and connected to the vessel and a locking collar is mounted to the gimbal table. A mating member is attached to the spar buoy. The vessel is maneuvered to bring the spar buoy within the gimbal table opening. With the spar buoy positioned within the gimbal table opening, the locking collar is arranged and designed to releasably attach to the mating member of the spar buoy and restrict relative vertical motion between the spar buoy and the vessel while the gimbal table allows the floating vessel to roll and pitch without driving these motions into the spar buoy.

An assembly includes first and second tubular members of a wind turbine support structure. The second member has a fork-shaped cross section with a main body between two substantially parallel walls that each comprise at least one through hole, the first member is between the two walls of the second member, and the through holes of the first and second member define a channel. A connector insertable in the channel is consecutively radially expandable. An actuator is configured to move the connector in an axial direction in said channel. The connector, when expanded, pushes the first member in a radial direction relative to said channel against the second member to define a clamping contact and thereby a pre-tensioned connection in said radial direction between a face of the first member and a face of the main body of the second member. A method of assembling the assembly.

A fatigue resistant gravity based spread footing under heavy multi-axial cyclical loading of a wind tower. The foundation having a central vertical pedestal, a substantially horizontal continuous bottom support slab, a plurality of radial reinforcing ribs extending radially outward from the pedestal. The pedestal, ribs and slab forming a continuous monolithic structure. The foundation may have a three-dimensional network of post-tensioning elements that keep the structural elements under heavy multi-axial post compression with a specific eccentricity intended to reduce stress amplitudes and deflections and allows the foundation to have a desirable combination of high stiffness and superior fatigue resistance. The foundation design reduces the weight and volume of materials used, reduces cost, and improves heat dissipation conditions during construction by having a small ratio of concrete mass to surface area thus eliminating the risk of thermal cracking due to heat of hydration.

There is provided high power laser systems, high power laser tools, and methods of using these tools and systems for cutting, sectioning and removing structures objects, and materials, and in particular, for doing so in difficult to access locations and environments, such as offshore, underwater, or in hazardous environments, such as nuclear and chemical facilities. Thus, there is also provided high power laser systems, high power laser tools, and methods of using these systems and tools for removing structures, objects, and materials located offshore, under bodies of water and under the seafloor.