Abstract: The invention relates to a method for drilling shafts (2) in ground layers (3). The method comprises of arranging a borehole casing (4) in the ground (3), lowering into the borehole casing (4) a hollow drill string (5) provided with a drill head (7) with cutting tools (8), arranging a water column (10) in the borehole casing (4), and then setting the drill string (5) into rotation (20) in the borehole casing (4) so that ground material (31) is dislodged by the cutting action of the cutting tools (8). At the position of the drill head (7) a first fluid (26) is injected under a first pressure into the ground layers (3) by means of one or more nozzles (25). The method has a higher drilling efficiency than the known method. The invention also relates to a device for performing the method, and a jack-up pontoon provided with the device.

Abstract: The application relates to an efficient method of providing a foundation for an elevated mass, such as the jacket of a wind mill, the foundation consists of a plurality of piles, driven into a substrate according to a geometric pattern. The method an assembly of a jack-up platform and a framed template, the template having a plurality of interconnected sleeve guide members for receiving the piles, arranged according to the geometric pattern, and means for slidably moving it along the spud poles of the platform. The framed template is lowered along the spud poles from an in-operative position close to the deck of the platform towards the substrate, and piles driven into the substrate through the sleeve guide members of the template. The invention also relates to a framed template and to an assembly of a jack-up platform and a framed template, adapted for carrying out the method.

Abstract: The invention relates to a device for manufacturing a foundation for a mass located at height, such as the jacket of a wind turbine or a jetty, wherein the foundation comprises a quantity of piles driven into an underwater bottom in a geometric pattern. The device comprises a positioning framework of a number of mutually connected guide tubes arranged in a geometric pattern and adapted to receive and guide a pile to be driven into the underwater bottom, wherein the guide tubes comprise a mechanism with which at least an internal wall part of the guide tubes is displaceable in the radial direction of the guide tubes from a radially inward support position for the pile to a radially more outward position in which the internal wall part substantially releases the pile. The invention also relates to a method and an assembly of a jack-up platform and the device.

Abstract: The invention relates to a method for erecting at sea a large slender body, such as the monopile of a wind turbine. The method comprises bringing the large slender body in a substantially horizontal floating condition at least partly underneath the work deck of a platform, attaching a tension cable to the slender body, and pulling on the tension cable using fixations means and guiding means that are provided at an edge of the work deck and are connected to it to gradually bring the slender body in an erected position along the edge of the work deck. The slender body is optionally driven into the under water bottom. The invention also relates to a device for performing the method. The method is reliable and obviates the use of large cranes.

Abstract: A device for manufacturing a foundation for a mass located at height, such as the jacket of a wind turbine or a jetty, wherein the foundation comprises a quantity of piles driven into an underwater bottom in a geometric pattern. The device comprises a positioning framework of a number of mutually connected guide tubes arranged in a geometric pattern and adapted to receive and guide a pile to be driven into the underwater bottom, wherein the guide tubes comprise measuring means adapted to determine the height of a pile present in the guide tubes.

Abstract: The invention relates to a device for assembling a rotor of a wind turbine at sea. The device has a support structure that is provided with a rotating table for rotating the hub of a rotor around the hubs longitudinal axis. The support structure is further adapted to be connected to an offshore platform such that the rotating table may be positioned outside the periphery of the platform. The invention also relates to an assembly of an offshore platform and the device, connected thereto. The invention further relates to a method for assembling a rotor of a wind turbine at sea, and to a method of assembling a wind turbine at sea, using the device and assembly. The device and method provide a more efficient assemblage.

Abstract: The invention relates to an efficient method for providing a foundation for a mass located at height, such as the jacket of a wind turbine or a jetty, wherein the foundation comprises a number of piles driven into a bottom in a geometric pattern. The method comprises of providing a floating device provided with lifting means; providing a positioning frame comprising a number of mutually connected guide sleeves arranged in a geometric pattern for the purpose of receiving the piles; lowering the positioning frame to the bottom into a position of use via the lifting means; and arranging the piles in the bottom through the guide sleeves of the positioning frame in the position of use, and to a positioning frame adapted to perform the method.

Abstract: The invention relates to a device for manufacturing a foundation for a mass located at height, such as the jacket of a wind turbine or a jetty, wherein the foundation comprises a quantity of piles driven into an underwater bottom in a geometric pattern. The device comprises a positioning framework of a number of mutually connected guide tubes arranged in a geometric pattern and adapted to receive and guide a pile to be driven into the underwater bottom, wherein the guide tubes comprise measuring means adapted to determine the height of a pile present in the guide tubes. The invention also relates to a method and an assembly of a jack-up platform and the device.

Abstract: The invention relates to a device for manufacturing a foundation for a mass located at height, such as the jacket of a wind turbine or a jetty, wherein the foundation comprises a quantity of piles driven into an underwater bottom in a geometric pattern. The device comprises a positioning framework of a number of mutually connected guide tubes arranged in a geometric pattern and adapted to receive and guide a pile to be driven into the underwater bottom, wherein the guide tubes comprise a mechanism with which at least an internal wall part of the guide tubes is displaceable in the radial direction of the guide tubes from a radially inward support position for the pile to a radially more outward position in which the internal wall part substantially releases the pile. The invention also relates to a method and an assembly of a jack-up platform and the device.

Abstract: A device for assembling a large structure at sea, particularly a wind turbine. The device includes a support structure which can be arranged relative to a transport vessel, wherein a part of the support structure is movable from a transport position, in which the component is transported, to an assembly position in which the component is rotated and/or tilted relative to the transport position. The movable part is provided can be fixed in place. A method for assembling a large structure at sea making use of the device.

Abstract: A jack-up offshore platform includes a work deck and a lifting device for manipulating a load from the work deck. The lifting device includes a main boom for manipulating the load, which main boom is pivotally connected to a support structure at a pivot. The support structure is provided to support the pivot in an elevated position with respect to the work deck, which allows manipulation of heavier loads and moreover saves space on the work deck. In a preferred embodiment, the platform further includes a counterbalancing structure that is connectable to the platform and/or the support structure. Also included is the use of the platform for assembling and servicing a structure at sea.

Abstract: The invention relates to a method for erecting at sea a large slender body, such as the monopile of a wind turbine. The method comprises bringing the large slender body in a substantially horizontal floating condition at least partly underneath the work deck of a platform, attaching a tension cable to the slender body, and pulling on the tension cable using fixations means and guiding means that are provided at an edge of the work deck and are connected to it to gradually bring the slender body in an erected position along the edge of the work deck. The slender body is optionally driven into the under water bottom. The invention also relates to a device for performing the method. The method is reliable and obviates the use of large cranes.

Abstract: The invention relates to a device for assembling a rotor of a wind turbine at sea. The device comprises a support structure that is provided with means for rotating the hub of a rotor around the hubs longitudinal axis. The support structure is further adapted to be connected to an offshore platform such that the rotating means may be positioned outside the periphery of the platform. The invention also relates to an assembly of an offshore platform and the device, connected thereto. The invention further relates to a method for assembling a rotor of a wind turbine at sea, and to a method of assembling a wind turbine at sea, using the device and assembly. The device and method provide a more efficient assemblage.

Abstract: The application relates to an efficient method of providing a foundation for an elevated mass, such as the jacket of a wind mill, the foundation consists of a plurality of piles, driven into a substrate according to a geometric pattern. The method an assembly of a jack-up platform and a framed template, the template having a plurality of interconnected sleeve guide members for receiving the piles, arranged according to the geometric pattern, and means for slidably moving it along the spud poles of the platform. The framed template is lowered along the spud poles from an in-operative position close to the deck of the platform towards the substrate, and piles driven into the substrate through the sleeve guide members of the template. The invention also relates to a framed template and to an assembly of a jack-up platform and a framed template, adapted for carrying out the method.

Abstract: A jack-up offshore platform, on which is provided a lifting crane for lifting a load, which lifting crane includes structure connectable to the platform for counterbalancing the load. The counterbalancing structure may include at least one counterbalancing cable for operably connecting to the platform. A lifting crane provided with counterbalancing structure connectable to a jack-up offshore platform, and to a method of repositioning a load from a platform.