Itrec B.V.

A method for pile installation wherein use is made of a vessel for pile installation. A pile holding system is mounted to the hull of a vessel, e.g. on deck ( 2 ) of a vessel, which pile holding system is configured to hold the pile in an upright orientation at a pile installation location at least whilst suspended from a crane by means of one or more winch driven cables, e.g. for installation of a pile adapted to support an offshore wind turbine, the pile holding system comprises a pile holding tool ( 40 ). The pile holding tool ( 40 ) further comprises a damping system including at least one damping device ( 45 ) that is mounted to the base structure ( 42 ) and is configured to, in use, engage on the pile suspended from the crane at a location that is vertically spaced from the circumferential zone that is engaged by the plurality of pile engaging positioning devices ( 43 ) of the pile holding tool, and wherein the at least one damping device ( 45 ) is configured to dampen pendulum motion of the pile suspended from the crane.

A heave tolerant pile guiding device for guiding a pile including a cylindrical section and above said cylindrical section a tapered section that narrows in upward direction. The device includes a frame to be mounted to a vessel having a hull subject to sea-state induced motion during installation of a pile. At least one pair of first and second pile engaging devices is arranged on the frame diametrically opposed relative to a center axis. Each pile engaging device comprises a pile engaging member and a hydraulic cylinder to move the member radially relative to the center axis. A hydraulic system includes a position control circuit and a sphincter control circuit. The sphincter control circuit is configured to operate the pair of first and second hydraulic cylinders in particular when the pile engaging members engage on the tapered section of the pile. The sphincter control circuit is a rotary flow divider.

A system for holding a pile and being mounted on a vessel includes a support assembly and a pile holder. The support assembly provides compensation for wave-induced motion of the vessel to maintain a predetermined X-Y location of the pile holder. The pile holder has a center axis and is mounted on the support assembly so as to be tiltable about a substantially horizontal tilt axis relative to the support assembly. The pile holder has at least one ring which includes a ring structure and multiple pile engaging devices connected to the ring structure of the ring, distributed about the circumference of the ring. The substantially horizontal tilt axis of the system is located, with the pile extending substantially vertically through the at least one ring, further forward from the location at which the support assembly is mounted to the vessel than the center axis of the pile holder.

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.

A method for pile installation wherein use is made of a vessel for pile installation. A pile holding system is mounted to the hull of a vessel, e.g. on deck ( 2 ) of a vessel, which pile holding system is configured to hold the pile in an upright orientation at a pile installation location at least whilst suspended from a crane by means of one or more winch driven cables, e.g. for installation of a pile adapted to support an offshore wind turbine, the pile holding system comprises a pile holding tool ( 40 ). The pile holding tool ( 40 ) further comprises a damping system including at least one damping device ( 45 ) that is mounted to the base structure ( 42 ) and is configured to, in use, engage on the pile suspended from the crane at a location that is vertically spaced from the circumferential zone that is engaged by the plurality of pile engaging positioning devices ( 43 ) of the pile holding tool, and wherein the at least one damping device ( 45 ) is configured to dampen pendulum motion of the pile suspended from the crane.

A pile holding system is to be mounted on a deck of a vessel, e.g. for installation of a pile adapted to support an offshore wind turbine. The pile holding system is configured to support the pile in an upright position at a pile installation location next to the vessel. A vessel is provided with such a pile holder system. A method for installation of a pile and a pile holder are also disclosed.

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.

A pile holding system is to be mounted on a deck of a vessel, e.g. for installation of a pile adapted to support an offshore wind turbine. The pile holding system is configured to support the pile in an upright position at a pile installation location next to the vessel. A vessel is provided with such a pile holder system. A method for installation of a pile and a pile holder are also disclosed.

A semi-submersible floating offshore vessel has a deckbox structure with a main deckbox bottom extending underneath a lower deck. The deckbox structure includes a recessed cellar deck structure that protrudes below the main deckbox bottom, which recessed cellar deck structure has a cellar deck bottom wall that is closed and wave impact resistant and which recessed cellar deck structure has a peripheral wall that is closed and wave impact resistant. The peripheral wall extends between an outer perimeter of the cellar deck bottom wall and the main deckbox bottom of the deckbox structure. The moonpool extends through the recessed cellar deck structure. Seen in plan view, the recessed cellar deck structure includes a number of pointed wave crest splitting sections.

A semi-submersible drilling vessel has a deckbox structure, one or more pontoons, and multiple support columns extending upward from the one or more pontoons and supporting thereon the deckbox structure. An annular riser joints storage caisson extends downwardly from the deckbox structure, wherein the storage caisson delimits an annular storage space configured for storage therein of an annular array of riser joints in vertical orientation thereof. A riser joints carousel device is provided in the annular storage space, which riser joints carousel device is configured to carry an annular array of riser joints in vertical orientation thereof in a mobile manner relative to the annular storage caisson so that the array of riser joints is movable along an annular path through the storage spaced between the inner and outer wall of the storage caisson. The deckbox structure is provided with a riser joint transfer passage at a riser joint transfer location above the annular path of the riser joints carried by the riser joints carousel device through the storage space. The vessel is provided with a riser joint vertical transfer device configured to lift and lower a riser joint out of and into the riser joints carousel device, passing therein vertically through the riser joint transfer passage of the deckbox structure.