The present invention relates to an assembly for installing a pile (2) in a seabed (3), the assembly comprising a vessel (23) comprising a positioning system for keeping the vessel (23) at an installation location relative to the seabed, the positioning tem (5) having a positioning stiffness (7); a pile guiding system configured to guide the pile (2) during installation thereof, the pile guiding system comprising a base (9) provided on the vessel; a first guiding device connected to the base, the first guiding device being configured to accommodate the pile during installation thereof; a resilient member (11) for providing a resilient connection between the vessel (23) and the pile during installation thereof for allowing relative motions between the pile (2) and the vessel (23), the resilient member having a connection stiffness, wherein the resilient member (11) is configured and intended to keep a natural period of a pivoting movement of the pile about the seabed caused by waves during installation thereof longer than a dominant wave period of a wave spectrum at the installation location by providing the resilient connection with a low connection stiffness.

A pile upending and holding system includes a support assembly configured to be mounted on the vessel and to provide compensation for wave-induced motion of the vessel to maintain a predetermined X-Y location of the pile holder independent of said motion, and a pile holder mounted on the support assembly to be tillable about a substantially horizontal tilt axis. The pile holder includes a lower ring and an upper ring, and a pile holder frame supporting the lower ring and upper ring, the upper ring longitudinally spaced from the lower ring. Each of the rings include pile engaging devices distributed about the circumference thereof, each pile engaging device being adapted to engage an exterior of the pile extending through the lower and upper ring. Each of the lower ring and upper ring includes a ring base fixed to the pile holder frame and one or more movable jaws, movable between a closed position for holding and guiding the pile and an opened position for entry of the pile. The pile holder is provided, below the lower ring thereof, with a pile foot end support for engaging a longitudinal end of the pile to limit longitudinal movement thereof.

Described is a device for providing a sizeable, slender object having a longitudinal direction into an underwater bottom from a deck of a vessel. The device includes a lifting means configured to take up the object at a lifting point thereof and position it on the underwater bottom; an upending tool connected to an edge of the vessel and configured to engage a first circumferential part of the object suspended from the lifting means and provide a pivot around which the object can be upended; and a gripping tool connected to an edge of the vessel and configured to engage a second circumferential part of the object suspended from the lifting means, whereby the first and second circumferential parts are optionally spaced apart in the longitudinal direction of the object. The gripping tool includes an actuator system configured to act on at least one of the upending tool and the gripping tool and control movements of at least one of the first and the second circumferential parts, relative to the vessel. A method using the device is also described.

An annular seal member comprising a seal body comprising a locating portion locatable against a wall element of an offshore structure, an inner surface, an outer surface and a lip portion that defines an open mouth of the seal member for receiving an elongate element therethrough; wherein the seal body is locatable against the wall element such that when a static pressure acting on the outer surface of the seal body exceeds a static pressure acting on the inner surface of the seal body a net positive pressure is exerted on the outer surface which at least partly deforms inwardly to provide a portion of the seal body for sealing against an outer surface of the elongate element. An offshore structure.

A monopile comprising a body (1) having a hollow interior, a toe (9) at a distal end for insertion into a soil (19) during monopile installation, and a proximal end region (2) for supporting a structure (7), such as a wind turbine tower, once the monopile has been installed. The body (1) further comprises a door aperture (12) provided in the body (1) for accessing the interior of the body (1). The door aperture (12) is configured to receive a door assembly (6,18) once the monopile (1) has been installed.

Disclosed is a system for the temporary holding, during pile driving operations, of a foundation pile intended to receive the mast of an offshore wind turbine. The temporary holding system includes a sleeve intended to receive a section of the foundation pile and a support frame intended to be secured to a floating device. The support frame includes a slide and an actuator, arranged to generate displacements of the sleeve according to the two translational degrees of freedom. The slide includes at least one rolling element including a cylindrical roller.

An annular seal member comprising a seal body comprising a locating portion locatable against a wall element of an offshore structure, an inner surface, an outer surface and a lip portion that defines an open mouth of the seal member for receiving an elongate element therethrough; wherein the seal body is locatable against the wall element such that when a static pressure acting on the outer surface of the seal body exceeds a static pressure acting on the inner surface of the seal body a net positive pressure is exerted on the outer surface which at least partly deforms inwardly to provide a portion of the seal body for sealing against an outer surface of the elongate element. An offshore structure.

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.

An off-shore wind turbine system is assembled using a platform or jack-up vessel, and a first base anchored to the seafloor at a bade assembly off-shore location. A buoyant tower is attached to the first base. A crane provided on the platform or jack-up vessel is used to lift blades and blades, which are then coupled to a turbine held in a nacelle provided at the top of the buoyant tower. The buoyant tower, the nacelle, and the blades are detached from the first base. The buoyant tower, the nacelle, and the blades are towed to a wind farm and connected to a second base provided in the wind farm. The buoyant tower, the nacelle, and the blades are further stabilized using mooring lines spanning between the buoyant towers and other bases provided in the wind farm. The first base and/or the second base include anti-rotation features.

To upend and lift an object, e.g. a foundation member of an offshore wind turbine, e.g. a monopole, use is made of an upending and lifting tool, wherein, with the tool suspended from one or more hoisting cables, e.g. from a crane hook of a crane, and with the frame of the tool initially in vertical orientation, a routine is performed which includes operating one or more shifting actuators, thereby moving a cable shifting member and engaging a cable engagement surface with the one or more hoisting cables at a height above a pivot axis. Further continuing this motion of the cable shifting member and thereby applying a cable shifting force on the one or more hoisting cables results, in reaction, in a pivoting of the frame into the horizontal orientation thereof.