Itrec B.V.

A crane with a tagline system, for example for use in the handling of one or more wind turbine components, e.g. handling of a rotor blade. The crane comprises a boom with a boom leg embodied as a latticed hollow box structure. At least one of the front main chords of the boom leg is formed from four steel planar plate members that are welded to one another in a rectangular or square cross-sectional arrangement. The front plate member extends from a corner joint with the outer plate member inward beyond the joint to the inner plate member to form an inwardly protruding guide rail portion. The outer plate member extends from the corner joint with the front plate member rearward beyond the joint to the rear plate member to form a rearwardly protruding guide rail portion. The tagline trolley is provided with rollers engaging the inwardly protruding guide rail portion and with roller engaging the rearwardly protruding guide rail portion.

A marine slewing pedestal crane includes a boom provided with a jib having a jib-arm. The jib includes a jib base pivotally connected to a jib-axle to allow a pivotal movement of the jib with respect to the boom. The crane includes a jib positioning assembly adapted to position the jib arm and to actuate the movement of the jib arm. The jib arm positioning assembly includes a jib arm control system, including one or more sensors for monitoring a load connected to a load suspension device of a hoisting assembly of the crane, and/or a potential load, and/or a supply vessel supporting a potential load, and/or crane information. Based on the information, the jib arm control system actuates one or more cylinders to pivot the jib arm relative to the jib base.

A pile driving method for driving a hollow tubular pile having a vertical centreline, a top end and an open foot end vertically into the soil, e.g. into the seabed, e.g. a large diameter pile having an outer diameter at the open foot end of at least 5 meters, e.g. a monopile of an offshore wind turbine, wherein use is made of a pile driving system, wherein the system includes at least one hammer device and a torsional vibration drive.

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 slew bearing for rotatably supporting an object on a base about a slew axis. The slew bearing includes a stationary ring and a rotary ring part. The stationary ring part is provided with a stationary raceway member forming a stationary raceway surface oriented substantially perpendicular to the slew axis. The rotary ring part is provided with a rotary raceway member forming a rotary raceway surface. Rolling elements are provided between the stationary raceway surface and the rotary raceway surface. The slew bearing further includes an elastically compressible resilient insert sandwiched either between the rotary raceway member and the rotary ring part or between the stationary ring part and the stationary raceway member. The slew bearing further includes an axial load sensor for monitoring an axial load on the slew bearing by measuring a distance over the resilient insert.

An assembly for supporting an object on a rail comprises a load bearing housing and an endless chain of steel cylindrical rollers arranged for recirculating along a closed path. The assembly comprises an elastically compressible resilient insert which is sandwiched between a steel central body and a steel raceway member above a work portion of the path, so that the central body is resiliently supported on an operative set of the cylindrical rollers via the insert and the steel raceway member.

A crane for use on an offshore vessel is provided with a boom restrainer, wherein the boom restrainer is a hydro-pneumatic boom restrainer, for reducing upward pivoting of the boom, when the boom is in the top zone, wherein the boom restrainer includes: multiple hydraulic cylinders, each having a hydraulic circuit and a cylinder rod with a cylinder head, wherein the cylinders are mounted on the crane structure with the cylinder heads directed towards the boom of the crane, preferably are mounted on a stay of the crane structure, a catcher for each hydraulic cylinder, wherein each catcher is mounted on the boom and is configured for receiving the cylinder head of the corresponding hydraulic cylinder, and to lock the cylinder head, preferably pivotable locks the cylinder head, relative to the boom, when the boom pivots upwards in the top zone; a gas buffer for each hydraulic cylinder, wherein each gas buffer is mounted to the corresponding hydraulic cylinder, and is connected to the hydraulic circuit of the corresponding hydraulic cylinder via a medium separator, wherein the gas buffer forces the hydraulic cylinder in an extended position, and wherein the volume ratio between the hydraulic cylinder and the gas buffer is such that the hydraulic cylinder acts as a progressive spring, e.g. the gas buffers each have a size in the range of 1000-1400 litre, for example 1200 litre and the hydraulic cylinders each have a size in the range of 800-1000 litre, for example 900 litre, and preferably the ratio between the volume of the gas buffer and the volume of the associated hydraulic cylinder is 4:3.

The invention relates to a pile gripper positioning system for a pile gripper that is configured to be provided on a vessel to engage with a monopile during a monopile installation method, wherein the pile gripper positioning system comprises: —an actuator system for applying forces to the pile gripper to position the pile gripper relative to the vessel, —a measurement system for determining a position of the monopile in the pile gripper relative to the vessel, and—a pile gripper control unit for driving the actuator system in dependency of a desired position and an actual position of the monopile as measured by the measurement system, wherein the pile gripper control unit is configured to receive a signal representative for a position of the vessel, wherein, during at least a portion of the monopile installation method, the pile gripper control unit is configured to determine a drive signal for the actuator system to compensate at most a portion of a deviation of the position of the vessel from a desired position of the vessel, and wherein, during said at least a portion of the monopile installation method, the pile gripper control unit for driving the actuator system is configured to drive the actuator system in dependency of a desired position and an actual position of the monopile as measured by the measurement system, and the drive signal to compensate at most a portion of a deviation of the position of the vessel from a desired position of the vessel.

The invention relates to a crane for assembly and installation of offshore wind turbines on an offshore location, to a vessel for assembly and installation of offshore wind turbines on an offshore location, and to a method for assembly and installation of offshore wind turbines on an offshore location. According to the invention the crane is provided with a base section and a top section, wherein the top section is rotatable supported by a bearing, and can be rotated with the wind turbine hoisting device relative to the base section about a vertical axis, wherein a first trolley guide is mounted to a top section of the installation crane for giding a vertically mobile wind turbine supporting trolley. According to the invention the vessel is provided with one or more assembly stations on different sides of the installation crane.

For installing a blade on a horizontal axis rotational hub of an offshore wind turbine, use is made of a blade installation device that is temporarily installed on the offshore wind turbine. A mounting part is mounted on the foundation of the offshore wind turbine and/or on a lower portion of the wind turbine mast. A crane mast is erected vertically and is supported by the mounting part. The crane mast has a track. A blade manipulator assembly includes a trolley moving over the track and one or more blade root engagement members that engage a root end of the blade. The blade installation device includes a hoist system with a crane boom that is mounted to a top end of the crane mast, a winch, and a winch driven cable. In the method, the trolley is brought in a lower position thereof and the blade root engagement members engage on the root end of the blade that is in the lower receiving position thereof. The cable of the hoist system is attached to the blade at a distance remote from the root end, preferably at a center of gravity of the blade. The method includes the lifting of the blade to the blade installation position by operating the winch of the hoist system and simultaneously moving the trolley along the track by the trolley drive.