Title: Adjustable pile holding system, vessel and pile installation method

The invention relates to a pile holding system to be mounted on a deck of a vessel, e.g. for installation of a pile adapted to support an offshore wind turbine, which pile holding system is configured to support the pile in an upright position at a pile installation location next to the vessel. The invention further relates to a vessel comprising such a pile holding system and a pile installation method in which use is made of such a vessel and/or pile holding system.

Installation of an offshore wind turbine may comprise the step of installing the foundation, in the form of a pile, of the offshore wind turbine. The pile is installed by driving the pile into the sea bottom after which the upper part of the wind turbine may be installed on top of the pile.

In known methods the pile is transported to the installation location on board a vessel. Once the vessel has arrived at the pile installation location the pile is set up at the pile installation location for driving. During driving the pile is supported by a pile holding system comprised on the vessel.

To enable the pile holder to support the pile during driving, the pile holder is to be supported outside the contour of the vessel. Preferably, the pile holder is not permanently fixed in that outboard position, and can be moved into a storage position when not needed for supporting a pile. When stored, the pile holder no longer protrudes beyond the contour of the vessel, which facilitates moving the vessel relative to other vessels and obstacles.

CN 102660950 discloses a pile holding system comprising a pile holder and a pile holder support system. The pile holder support system comprises a frame that is to be mounted on the deck of a vessel to support the pile holder in an outboard positon, i.e. outside the contour of the vessel. The pile holder support system is furthermore configured to move the pile holder relative to the pile holder support system, to allow for adjusting the outboard position of the pile holder relative to the vessel for supporting the pile in an upright position at the correct pile installation location. The pile holding system is not configured to move the pile holder from the outboard position into an inboard position, i.e. into a position in which the pile holder is located within the contour of the vessel.

Because the deck space on most vessels is a limited commodity, the foot print of a pile holding system is preferably kept minimal. Also, it is preferred that the pile holder, when stored, takes up minimal deck space. In some prior art, the pile holding system is removed by a crane when not in use, and is stored on deck or on a support vessel. Removing and installing the pile holding system is an elaborate process. Therefore, pile holding systems have been developed that can be switched between an active position, in which the pile holder can be used for supporting a pile, and an inactive position in which the pile holder for example is folded along the hull of the vessel.

EP2886722 discloses a pile holding system comprising a support frame and a pile holder.

The support frame is hingeable mounted to the deck of the vessel, such that the frame can be pivoted between a raised position and a lowered position. In the raised position, the frame positions the pile holder in a tilted position and close to the contour of the vessel. In the lowered position, the frame supports a pile holder in a horizontal holding positon, outside the contour of the vessel, for supporting that pile in an upright position. Pivoting the pile holder between an inboard position and an outboard position, requires an elaborate frame and thus provides the pile holding system with a large foot print. Furthermore, due to the elaborate frame, the pile holder is supported relatively far from the hull of the vessel during installation of the pile, which requires an extra rigid, and thus heavy, frame.

Installation of piles is currently done using jack-up vessels in which legs are lowered into the water to lift the vessel at least partially out of the water so that waves have a limited or minimal effect on the vessel. However, a drawback of such a jack-up type vessel is that it takes a lot of time to lower the legs and to lift the vessel out of the water and to go through the reverse process after installation of the pile.

It is furthermore submitted that there is a trend towards larger wind turbines and a desire to install offshore wind turbines at locations with larger water depths than currently encountered. Both result in larger and heavier foundations. Hence, it is expected that in the near future piles need to be installed that are larger than 100 metres, possibly 120 metres or lager. The weight of such piles may be larger than 1000mt, possibly 1300mt or above.

It is an object of the invention to provide an alternative pile holding system. It is a further object of the invention to provide an improved pile holding system to be mounted on a deck of a vessel for installation of a pile adapted to support an offshore wind turbine, a vessel comprising such a pile holding system and a method for installation of a pile adapted to support an offshore wind turbine. It is yet another object of the invention to provide an alternative pile holding system. It is yet another object of the invention to provide an improved pile holding system which allows more effective installation of a pile. It is another object of the invention to provide an alternative pile holding system. According to a first aspect of the invention, According to a first aspect of the invention, there is provided a pile holding system to be mounted on a deck of a vessel, e.g. for installation of a pile adapted to support an offshore wind turbine, which pile holding system is configured to support the pile in an upright position at a pile installation location next to the vessel, the pile holding system comprising:

a pile holder comprising a base structure, a first jaw and a second jaw, the first jaw and the second jaw each extending between an inner end and an outer end, and wherein the first and second yaw are pivotable connected at the inner end thereof to a respective pivot part of the base structure to pivot about a yaw pivot axis between a closed position, in which the pile holder defines a pile passage for the pile held in the pile holder, and an open position, to allow the pile to be received in, or to be removed from, the pile holder in a lateral direction;

a plurality of pile engaging devices, wherein the base structure, the first jaw and the second jaw each support at least one pile engaging device, the engaging devices each comprising one or more pile engaging elements, e.g. each comprising one or more pile guiding rollers for engaging the pile in the pile passage; and

a pile holder support system to be mounted on the deck of the vessel, wherein the support system moveably supports the pile holder, preferably at the base structure, and which support system is configured to move the pile holder in a first direction, which first direction, when the pile holding system is mounted on the deck of a vessel, is substantially parallel to the deck of the vessel, between an inboard position and an outboard position,

wherein the pile holder, when in the outboard position, is located outside a contour of the vessel, for holding the pile in the upright position at the installation location, and wherein the pile holder, when in the inboard position with the first and second jaw in the open position, is located within the contour of the vessel.

The pile holding system of the invention is to be mounted on a deck of a vessel, the vessel having a hull that supports the deck and that in a plan view defines a contour of the vessel.

When the pile holding system is mounted on the deck of a vessel, the first direction is substantially parallel to the deck of the vessel. Thus, when the pile holder is moved in the first direction it is moved in a substantially horizontal direction.

The pile holder support system is configured to support the pile holder in an outboard position, in which outboard position the pile holder can engage, with the pile engaging devices, a pile adapted to support an offshore wind turbine, and support that pile in an upright position at a pile installation location next to the vessel.

The pile holder support system is furthermore configured to move the pile holder in the first direction from that outboard position, in which the pile holder is located outside the contour of the vessel, into the inboard position, in which the pile holder is located inside the contour of the vessel. Thus, the pile holder can be moved parallel to the first direction between a position in which the pile holder, when seen in a plan view, is located next to the deck of the vessel, into a position in which the pile holder is located above the deck of the vessel.

With a pile holding system according to the claimed invention, the pile holder can be moved into the inboard positon by the pile holder support system. Moving the pile holder into the inboard position does not require the pile holder to be removed from the pile holder support system, and does not require demounting the pile holder support system from the deck of the vessel. Thus, the pile holder can be moved quickly and efficiently between the inboard position and the outboard position.

Furthermore, with the pile holding system according to the invention, opening the jaws reduces the size of the pile holder in the first direction, and thus the distance over which the pile holder is to be moved to bring it within the contour of the vessel is reduced.

According to the claimed invention, the pile holding system is configured, more in particular the pile holder support system and the pile holder are configured, to position the pile holder in the inboard position with the first and second jaw in the open position. Due to this open-jaw inboard position, the distance over which the pile holder is to be moved to bring it within the contour of the vessel is reduced, which speeds up the process.

Furthermore, due to the open-jaw inboard position of the pile holder, the footprint of the pile holder, when in the inboard position, has an elongated shape. Also, the footprint of the pile holder in the inboard position is located adjacent the contour of the vessel, and extends along the contour of the vessel, which furthermore allows for a pile holder support system located adjacent the contour of the vessel. In the prior art, the foot print of the pile holder support system comprises a large area, which area extends in a direction away from the contour of the vessel, and thus occupies more, and more useable, deck space. In this context it is noted that the deck space closely adjacent the contour of the vessel, is less suitable for storage of objects, and is less intensively used, compared to the deck space located further way from the contour of the vessel. With the pile holding system according to the invention, opening the jaws reduces the size of the pile holder in the first direction, and thus the distance over which the pile holder is to be moved to bring it within the contour of the vessel is reduced.

In an embodiment, the yaw pivot axis of the first yaw and the yaw pivot axis of the second yaw define a plane, wherein the outer ends of the first and second yaw are located at a side of the plane when the first yaw and the second yaw are in the closed position, and wherein the outer ends of the first and second yaw are located in the plane or at an opposite side of the plane when the first yaw and the second yaw are in the open position.

Such a configuration allows for the yaws to open wide, i.e. up to, or even beyond, the pivot part of the base structure, and more in particular allows for the yaws to be opened to such an extent that the base structure of the pile holder becomes the part of the pile holder that extends farthest in the first direction. Thus, with a pile holding system according to the claimed invention, moving the base part within the contour of the vessel, brings the entire pile holder, i.e. with the first yaw and second yaw in the open position, within the contour of the vessel.

In a further embodiment, the first yaw and the second yaw, when in the open-jaw

configuration, extend in opposite directions and substantially perpendicular to the first direction. In such an embodiment, the size of the pile holder in the first direction is minimal.

When the pile holder is in the inboard position, substantially the entire pile holding system is located within the contour of the vessel. An advantage of being able to fully retract the pile holder within the contour of the vessel is that large objects, e.g. a pilling hammer or transition piece, mounted on, or being part of, the pile, can easily pass the pile holding system.

In an embodiment, the pile holding system further comprises an actuation system configured to pivot the first yaw between its closed position and its open position and configured to pivot the second yaw between its closed position and its open position.

In an embodiment, the pile holder in the outboard position and in the inboard position has a horizontal orientation, and wherein the support system is configured to move the pile holder between the inboard position and the outboard position while maintaining the horizontal orientation of the pile holder.

In such an embodiment, the pile holder is supported in the inboard position in the same position it is used in, i.e. with a horizontal configuration in which a central axis defined by the pile holder, which central axis substantially coincides with the central axis of a pile supported by the pile holder, extends in the vertical direction. This facilitates a quick and efficient switch between the storage position and the holding positon, because there is no need for the pile holder to be for example pivoted into a tilted or upstanding position during the process.

In other words, because the pile holder, when in the inboard position, is supported in a horizontal position and with the jaws in the open position, the pile holder is supported in a positon ready for engaging a pile. The pile holder only needs to be moved in the first direction out of the inboard position, to engage a pile located adjacent the vessel at a pile installation location. This allows for a quick deployment of the pile holder.

Also, because the pile holder Is not tilted or pivoted when moved between the inboard position and the outboard position, it is supported in the inboard position having substantially the same orientation as when it is in the outboard position, i.e. has a horizontal orientation in both the inboard and the outboard position. Thus, an additional advantage of the current invention is that, while in the inboard position, the pile holder can be easily accessed for maintenance and inspection. This because the pile holder and its components can be accessed and checked in the same way and in the same position that these components are accessed and supported during use of the pile holder in the outboard position. For example a walkway provided on the pile holder to provide access to components of the pile holder during use, e.g. a hydraulic power source, can also be used when the pile holder is supported in the inboard position. This allows for a simple design of the pile holder.

In an alternative embodiment, the base structure of the pile holder is pivotally mounted to the support system, to enable the pile holder to be pivoted relative to the support system about a base structure pivot axis between a substantially vertical orientation, when in the inboard position, and a substantially horizontal orientation, when in the outboard position. In this example it is envisaged that the pile holder is tilted in the substantially vertical orientation when in the inboard position, in view of sailing with the vessel, mooring in a port, etc., while the pile holder is tilted in the substantially horizontal orientation for supporting a pile, as it is envisaged that a pile is hoisted by a crane and placed in vertical orientation before engagement thereof by the pile holder.

In an embodiment, the pile holder support system comprises: a track, preferably a track to be mounted on the deck of the vessel, the track extending in the first direction, and a base carriage configured to support the base structure of the pile holder, which base carriage is furthermore configured for movement along the track between a positon for supporting the pile holder in the outboard position and a position for supporting the pile holder in the inboard position. In a further embodiment, the pile holder has a length in the first direction, and wherein the track has a length in the first direction, and wherein the length of the track, more in particular the travel distance of the base cart along the track when moving the pile holder between the inboard and the outboard position, is less than the length of the pile holder with the first yaw and the second yaw in the closed position, and the length of the track, more in particular the travel distance of the base cart along the track when moving the pile holder between the inboard and the outboard position, is substantially similar to, preferably is more than, the length of the pile holder with the first yaw and the second yaw in the open position.

Thus, the track length is kept short, and therefore the footprint of the pile holding system can be kept to a minimum.

In an embodiment, the pile holder has a length in the first direction, and wherein the track has a length in the first direction, and the length of the track, more in particular the travel distance of the base cart along the track when moving the pile holder between the inboard and the outboard position, is substantially similar to the length of the pile holder with the first yaw and the second yaw in the open position.

Thus, the track length is kept to a minimum, and therefore the footprint of the pile holding system can be kept to a minimum.

In an embodiment, the pile holder has a width in a direction perpendicular to the first direction, and the track has a width in a direction perpendicular to the first direction, and the width of the track is less than the width of the pile holder with the first yaw and the second yaw in the open position, preferably the width of the track is less than 60% of the width of the pile holder with the first yaw and the second yaw in the open position,

Thus, the track width is kept to a minimum, and therefore the footprint of the pile holding system can be kept to a minimum. In a further embodiment, the track comprises a single rail, and the pile holder extends on opposite sides of that rail. Thus, the direct footprint, i.e. the deck area covered by the rail, is kept to a minimum.

In a further embodiment, the first yaw and the second yaw, when in the open-jaw

configuration, extend in opposite directions and substantially perpendicular to the first direction, such that in a top view the pile holding system with the pile holder in the outboard position and the first yaw and the second yaw in the open position is T-shaped.

In an embodiment, the pile holder support system is configured for moving the pile holder in a second direction, which preferably is perpendicular to the first direction, between a first outer position and a second outer position, to allow the support system to position the pile holder in a horizontal plane relative to the vessel. Thus, when the pile holding system is mounted on the deck of the vessel, the pile holder is moved substantially parallel to the deck of the vessel when moved in the second direction.

The combination of movement in the first direction and the second direction, allows for positioning the pile holder in the horizontal plane relative to the vessel, more in particular allows for positioning the pile holder relative to the vessel when in the outboard position thus the pile holder can be correctly aligned with a pile at the installation location next to the vessel, to support the pile in the upright position. It is noted that the vessel with the pile holding system may not be entirely correctly positioned relative to the installation location. In such a case the pile holder support system may be used to correctly align the pile holder with the installation location. Also, during the driving of the pile into the sea bottom the pile may tilt, which deviation may be compensated for by adjusting the position of the pile holder, thu pushing the pile back into the upright position.

In an embodiment, the pile holder support system comprises a track, preferably a track to be mounted on the deck of the vessel, the track extending in the first direction, and a base carriage for movement along the track. In this embodiment, the base carriage is configured to support the base structure, and the base structure is moveable, preferably in a second direction perpendicular to the first direction, between a first outer position and a second outer position, to allow the pile holder support system to position the pile holder in a horizontal plane relative to the vessel.

In an alternative embodiment, the track may extend in the second direction and the base structure is moveable relative to the base carriage in the first direction.

In an embodiment, the track comprises one or more rails that extend in the first direction, and the pile holder support system comprises a base carriage configured to support the base structure of the pile holder, which base carriage is furthermore configured for movement along the track, i.e. along the one or more rails, between a positon for supporting the pile holder in the outboard position and a position for supporting the pile holder in the inboard position.

In an embodiment, the track comprises a single rail and a single carriage for movement along the track. In an alternative embodiment, the track comprises two rails, which rails are set up spaced from and parallel to each other. In such an embodiment, the base carriage preferably comprises a U-shaped carriage frame, the carriage frame comprising two legs, each leg extending along a rail of the track, and at least one cross section connecting the legs.

Preferably, the at least one cross section connects the legs at an end of the legs facing the pile holder. The at least one cross section preferably supports the base structure.

In an embodiment, the base carriage comprises a U-shaped carriage frame, the carriage frame comprising two legs, each leg extending along a track, preferably each leg extending along a rail of the track, and at least one cross section connecting the legs, wherein the at least one cross section preferably connects the legs at an end of the legs facing the pile holder, and wherein the at least one cross section preferably supports the base structure.

In an embodiment, the base carriage comprises a l-shaped or T-shaped carriage frame, the carriage frame comprising a part corresponding to the vertical bar of the l-shape or T-shape, wherein said part extends along a track, and wherein another track is provided at a free end of the l-shaped carriage frame or the part of the carriage frame corresponding to the horizontal bar of the T-shape, and wherein the base structure is moveable connected to said other track.

In an embodiment, the pile support system further comprises a control system, which control system is configured to provide active motion compensation in the horizontal plane while the pile holder supports the pile in the upright position at the installation location next to the vessel to compensate for movement of the vessel relative to the pile installation location.

In an embodiment, the pile holder support system further comprises a monitoring system that is configured to monitor the position and/or orientation of the pile while the pile is being loaded into the pile holder and/or while the pile holder supports the pile in the upright position at the pile installation location next to the vessel, and a control system that is configured to control movement of the first and second yaw and the support system.

In an embodiment, the control system is configured to move the pile away from the vessel by moving the pile holder towards and/or past the outboard position when the monitoring system indicates that the position and/or orientation of the pile exceeds a predetermined first value.

In an embodiment, the control system is configured to automatically move the first and second yaw to their respective open positions to avoid interference between the pile on the one hand and the first and second yaw on the other hand.

In other words, the control system may be configured to push the pile away from the vessel by moving the pile holder towards and/or past the outboard position when the jaws of the pile holder are in the open position, and/or to automatically open the jaws of the pile holder and moving the pile holder towards and/or past the outboard position, when the position and/or orientation of the pile exceeds a predetermined value.

In such embodiments, the support system is preferably configured to move the pile holder beyond the outboard position, in particular when the pile is not yet driven into the sea floor. Preferably, the control system is configured to encompass information regarding the installation of the pile, more in particular is able to monitor, e.g. using the monitoring system, if the pile is already driven into the sea floor and preferably only allows for pushing the pile away from the vessel when the pile is not yet mounted in the sea floor, and/or is no longer supported by a crane, and/or is configured to remove a connection between the pile and a crane supporting the pile.

In an embodiment, the control system is configured to move the pile holder away from the pile by moving the pile holder towards the inboard position when the monitoring system indicates that the position and/or orientation of the pile exceeds a predetermined second value. The first and second value may be the same. This embodiment may particularly be useful when the pile is already at least partially driven into the sea floor and pushing the pile away is no longer possible, feasible or desired.

The monitoring system may further be configured to monitor if the pile is already at least partially driven into the sea floor, so that the control system activates the above embodiment, i.e. function, when the pile is at least partially driven into the sea floor. Manual activation of this function is of course also possible.

In an embodiment, the first yaw and the second yaw are pivoted over an angle of about 90 degrees, when pivoted from the closed position into the open position, and preferably the first yaw and the second yaw, when in the open-jaw configuration, extend in opposite directions and substantially perpendicular to the first direction.

In an embodiment, the base section and the first yaw and the second yaw each extend along a 120 degree arc-shaped trajectory. The base section and the first and second yaw thus each may form one third of the circumference of the pile holder when the first and second yaw are in the closed position. In an embodiment, the first jaw and the second yaw and preferably the base structure each have a semi-circular configuration to provide the pile holder with an annular configuration having a circular inner circumference when the jaws are in the closed position.

In an embodiment, when the first yaw and the second yaw are in the closed position, the outer ends of the jaws join up, and wherein preferably a locking mechanism is provided to lock the first yaw and the second yaw in their closed positions, e.g. by connecting the outer ends to each other.

In an embodiment, the pile holder comprises a fender structure, preferably mounted on the base structure, for rough positioning of the pile and/or collision prevention between pile and other pile holder portions.

In an embodiment, each pile engaging device comprises a suspension arm, each suspension arm having an engaging end and a pivot end, wherein the suspension arm is at the pivot end pivotable supported, such that the suspension arm is pivotable about a pivot axis, preferably the pivot end being a top end of the suspension arm and the pivot axis preferably being a horizontal pivot axis, and wherein each suspension arm is at the engaging end provided with one or more pile engaging elements.

In an embodiment, each pile engaging device comprises a suspension arm actuator to position the suspension arm at different angular positions about the pivot axis to allow simultaneous engagement of all pile engaging devices with corresponding piles having different diameters when the first and second yaw are in their closed positions.

The above embodiments allow to adjust for changes in diameter of the pile being lowered through the pile passage while the pile engaging devices engages the outer surface of the pile. The suspension arm actuators may be controlled using a diameter adjustment system configured to keep pile centre fixed and allow pile engaging elements, e.g. rollers to translate substantially perpendicular to pile surface. An advantage thereof is that no slipping occurs over coating for conical sections of a pile.

In an embodiment, the pile engaging devices comprise a chassis, wherein the first yaw and the second yaw, and preferably the base structure, each comprise a track structure, e.g. a rack or rail section, extending along a longitudinal direction of the respective first yaw, second yaw or base structure, wherein the chassis of each of the pile engaging devices is moveably supported on one of the track structures, and wherein each chassis is provided with a drive adapted to move the chassis along the track structure.

In an embodiment, the suspension arm actuator is provided between the chassis and the suspension arm.

In an embodiment, the pile holder with the first yaw and the second yaw in the closed position forms an annular structure and the track structures extend along the inner circumference of the annular structure, preferably the complete inner circumference.

In an embodiment, the pile holding system further comprises a control system configured to control the drives of the pile engaging devices, and to drive the pile engaging device in unison along the track structures.

In an embodiment, the one or more pile engaging elements comprise pile guiding rollers, preferably comprise two or more pile guiding rollers supported in a carrier that is pivotably connected to a support end of a suspension arm to pivot about a carrier pivot axis, which suspension arm in turn is pivotable about a suspension arm pivot axis, wherein the pile guiding rollers each have an axis of rotation, wherein the pile guiding rollers are supported by the carrier such that their axis of rotation extend parallel to the carrier pivot axis, and wherein preferably the carrier pivot axis extends parallel to the suspension arm pivot axis.

An advantage of the pile guiding rollers is that the pile engaging device is enabled to follow the changes in the diameter of the pile being lowered through the pile passage while the pile engaging device engages the outer surface of the pile

In an embodiment, the track structures are semi-circular track structures.

The first aspect of the invention also relates to a vessel comprising a pile holding system mounted on a deck of the vessel, e.g. for installation of a pile adapted to support an offshore wind turbine, which pile holding system is configured to support the pile in an upright position at a pile installation location next to the vessel, the pile holding system comprising:

a pile holder comprising a base structure, a first jaw and a second jaw, the first jaw and the second jaw each extending between an inner end and an outer end, and wherein the first and second yaw are pivotable connected at the inner end thereof to a respective pivot part of the base structure to pivot about a yaw pivot axis between a closed position, in which the pile holder defines a pile passage for the pile held in the pile holder, and an open position, to allow the pile to be received in, or to be removed from, the pile holder in a lateral direction;

a plurality of pile engaging devices, wherein the base structure, the first jaw and the second jaw each support at least one pile engaging device, the engaging devices each comprising one or more pile engaging elements, e.g. each comprising one or more pile guiding rollers; and

a support system mounted on the deck of the vessel, wherein the support system moveably supports the pile holder at the base structure, and which support system is configured to move the pile holder in a first direction between an inboard position and an outboard position,

wherein the pile holder, when in the outboard position, is located outside the contour of the vessel, for holding the pile in the upright position at the installation location, and wherein the pile holder, when in the inboard position with the first and second jaw in the open position, is located within the contour of the vessel.

In an embodiment, the vessel has a longitudinal axis, the axis extending between a bow and an aft of the vessel, and wherein the pile holder when moved in the first direction is moved perpendicular to the longitudinal axis of the vessel.

In an embodiment, the pile holding system is arranged at a stern of the vessel to hold a pile outside the contour of the vessel seen from above at a stern side of the vessel.

In an embodiment, the vessel further comprises a crane to handle a pile, wherein the crane is arranged at a stern of the vessel in line with a centre of gravity of the vessel.

In an embodiment, the pile holding system is arranged next to the crane.

In an embodiment, the vessel further comprises a storage location at a stern of the vessel at a side of the crane opposite to the side where the pile holding system is arranged, which storage location allows to store a pile driving mechanism to drive a pile into a sea floor.

In an embodiment, the vessel comprises deck space to store piles in a horizontal orientation parallel to the longitudinal axis of the vessel.

The invention further relates to a method for installation of a pile adapted to support an offshore wind turbine, wherein at least partially use is made of a vessel according to the invention, and wherein the method comprises the following steps: a. transporting a pile to the offshore pile installation location;

b. moving the pile holder from the inboard position to the outboard position, with the first and second yaw of the pile holder in the open position;

c. lifting the pile at an upper end thereof, and positioning the pile in the pile holder; d. moving the first yaw and the second yaw of the pile holder to their closed positions; e. lowering the pile to the sea floor; and

f. driving the pile into the sea floor.

In an embodiment, the method further comprises the step of positioning the pile relative to the installation location using the support system of the pile holding system.

In an embodiment, during step e. the pile is held by the pile holder.

In an embodiment, during at least one or more steps, preferably all steps, the vessel is in floating condition.

In an embodiment, during step e. and/or step f., the pile holder is compensated for wave- induced motion of the vessel to maintain a predetermined X-Y location independent of the wave-induced motion of the vessel.

In an embodiment, the vessel also carries out step a.

In an embodiment, step c. and/or step e. is carried out by a crane on the vessel.

In an embodiment, positioning the pile in the pile holder is carried out such that the pile and the pile holder are moved relative to each other until the pile engages with the fender structure of the pile holder.

In an embodiment, the pile engages with the fender structure after positioning the pile in the pile holder, and wherein the pile engaging devices are operated to engage with the pile only after step d.

It is furthermore noted that installing an offshore foundation pile also often involves rotating the pile about its longitudinal axis to correctly position it on the pile installation site, prior to driving the pile into the sea bottom. The features of the pile, such as entry doors, mounting apertures, power cable access openings, etc, have to be correctly oriented. In the prior art, the pile is correctly orientated while it is supported by a crane in the pile holder, already engaged by pile engaging devices comprising rollers engaging the pile to centralise it in the pile holder. Typically, the prior art pile holder is provided with a pile drive, an additional device mounted on the pile holder that can contact the pile to rotate it about its longitudinal axis. The pile drive comprises a movably supported drive wheel with a vertical rotational axis. To orientate the pile, the drive wheel is set to the circumferential surface of the pile, and is driven to thus rotate the pile about its vertical axis. It is submitted that, while being rotated, the pile is also engaged by the pile engaging devices of the pile holder, to center the pile in the holder. Typically, the pile engaging devices engage the pile with rollers for contacting the pile, the rollers being supported such that the have a horizontal axis of rotation. Thus the rotational axis of the rollers extends perpendicular to the longitudinal axis of the pile. Therefore, the rollers do not roll with the pile, and the drive wheel has to be extra powerful, and be pressed hard onto the surface, to overcome the friction between the pile engaging devices and the pile, to rotate the pile. This makes the process of rotating the pile difficult to manage and imprecise.

Furthermore, the prior art configuration has problems with features provided on the outer surface of the pile, for example mooring lugs or entry ports, potentially colliding with the pile engaging devices and/or the pile drive during rotation. Thus preventing correct orientation and/or requiring lifting or lowering of the pile during the orientation process.

It is a further object of the invention to provide an alternative pile holding system. It is a further object of the invention to provide an improved pile holder which allows for improved pile orientation. It is a further object of the invention to provide an improved method for installation of a pile adapted to support an offshore wind turbine.

According to a second aspect, the invention provides a pile holder for use in a pile holding system to be mounted on a deck of a vessel, e.g. for installation of a pile adapted to support an offshore wind turbine, which pile holding system is configured to support the pile in an upright position at a pile installation location next to the vessel, wherein the pile holder comprises:

- a base structure, a first jaw and a second jaw, the first jaw and the second jaw each extending between an inner end and an outer end, and wherein the first and the second yaw are pivotable connected at the inner end thereof to a respective pivot part of the base structure to pivot about a yaw pivot axis between a closed position, in which the pile holder defines a pile passage for the pile held in the pile holder, and an open position, to allow the pile to be received in, or to be removed from, the pile holder in a lateral direction;

- track structures, e.g. a rack or rail section, comprised in the first yaw and the second yaw, and preferably the base structure, the track structures extending along a longitudinal direction of the respective first yaw, second yaw or base structure,

- three primary pile engaging devices, wherein the primary pile engaging devices each comprise a chassis, one or more pile engaging elements, e.g. each comprise one or more pile guiding rollers for engaging the pile in the pile passage, and an actuator to move the one or more pile engaging elements between an active position and a passive position for respectively engaging and releasing the pile located in the pile holder, and to allow

simultaneous engagement of all primary pile engaging devices with piles having different diameters, when the pile engaging elements are in the active position and the first and second yaw are in their closed positions, wherein the primary pile engaging devices further comprise a chassis, which chassis of each of the primary pile engaging devices is moveably supported on one of the track structures, wherein each chassis is provided with a drive adapted to move the chassis along the track structure, and therefore move the pile engaging devices, more in particular the pile engaging elements, along an inner circumference of the pile holder while engaging a pile, to rotate a pile supported by a crane in the pile holder about its longitudinal axis, and wherein the pile holding system further comprises a control system configured to control the drives of the pile engaging devices, and to drive the pile engaging devices in unison along the track structures.

It is submitted that the pile holder may also comprise four or more primary pile engaging devices, in which embodiment the control system is configured to drive all primary pile engaging device in unison along the track structures,

In an embodiment, a pile holder according to the claimed invention comprise three primary pile engaging devices, the primary pile engaging devices comprising a chassis that is moveably supported on one of the track structures provided on the pile holder. Each chassis is provided with a drive adapted to move the chassis along the track structure, and therefore move the pile engaging devices, more in particular the pile engaging elements, along an inner circumference of the pile holder while engaging a pile, to rotate a pile supported by a crane in the pile holder about its longitudinal axis.

Thus, with a pile holder according to the second aspect of the invention, there is no need for a pile drive, i.e. there is no need for a separate device configured to rotate the pile while supported by the crane. Furthermore, because the pile is rotated by the primary pile engaging devices, which engage the pile to also centralise it in the pile holder, the pile engaging devices, and thus the pile engaging elements contacting the outer surface of the pile, move with the pile. This allows for a more controlled process compared to the prior art, and thus for an efficient and precise orientation of the pile.

In an embodiment, the first yaw and the second yaw, and preferably the base structure, each comprise a track structure, e.g. a rack or rail section, extending along a longitudinal direction of the respective first yaw, second yaw or base structure. Preferably, the pile holder with the first yaw and the second yaw in the closed position forms an annular structure.

In an embodiment, the track structures are semi-circular track structures. The track structures are preferably aligned, i.e. extend along sections of a circle, the circle extending in a horizontal plane. In such an embodiment, the track structures may combine into a circular support track structure when the yaws of the pile holder are in the closed position.

In an embodiment, the pile holder with the first yaw and the second yaw in the closed position forms an annular structure and the track structures extend along the inner circumference of the annular structure, preferably the complete inner circumference. This, allows for pile engaging devices configured to travel along the entire inner circumference of the pile holder, and thus allows for rotating the pile over 360 degrees or more without the pile engaging devices having to release the pile.

In an embodiment, the one or more pile engaging elements of the primary pile engaging devices, comprise pile guiding rollers, preferably comprise two or more pile guiding rollers supported in a carrier that is pivotably connected to a support end of a suspension arm to pivot about a carrier pivot axis, which suspension arm in turn is pivotable about a suspension arm pivot axis, wherein the pile guiding rollers each have an axis of rotation, wherein the pile guiding rollers are supported by the carrier such that their axis of rotation extend parallel to the carrier pivot axis, and wherein preferably the carrier pivot axis extends parallel to the suspension arm pivot axis. An advantage of the pile guiding rollers is that the primary pile engaging devices are enabled to follow the changes in the diameter of the pile being lowered through the pile passage while the pile engaging device engages the outer surface of the pile.

In an embodiment, the pile holder further comprises three secondary pile engaging devices for engaging a pile when the primary pile engaging devices are in the passive position, wherein the secondary pile engaging devices each comprise one or more pile engaging elements, e.g. each comprise one or more pile guiding rollers for engaging the pile in the pile passage, and an actuator to move the one or more pile engaging elements between an active position and a passive position for respectively engaging and releasing the pile located in the pile holder, and to allow simultaneous engagement of all secondary pile engaging devices with piles having different diameters, when the pile engaging elements are in the active position and the first and second yaw are in their closed positions.

In such an embodiment, the control system of the pile holding system is configured to control the drives of the primary pile engaging devices, and to drive the primary pile engaging device in unison along the track structures, and to control the drives of the secondary pile engaging devices, and to drive the secondary pile engaging devices in unison along the track structures,

Providing three secondary pile engaging devices allows for the secondary engaging devices to engage the pile, and maintain its orientation, while the primary pile engaging devices release the pile. Thus, the primary pile engaging devices, after having been moved in one direction along the track structures to rotate the pile, can be moved in the opposite direction along the track structures, reengage the pile, and rotate the pile further. With such an embodiment, the track structures do not need to form a continuous track around the inner circumference of the pile holder to rotate the pile over 360 degrees. By repeatedly rotating the pile over a limited interval, the pile can still be rotated over 360 degrees or more.

In an embodiment, the secondary pile engaging devices further comprise a chassis, which chassis of each of the secondary pile engaging devices is moveably supported on one of the track structures, and wherein each chassis is provided with a drive adapted to move the chassis along the track structure, and therefore move the pile engaging devices, more in particular the pile engaging elements, along an inner circumference of the pile holder while engaging a pile, to rotate a pile supported by a crane in the pile holder about its longitudinal axis. Thus, the pile can be rotated by both the primary pile engaging devices and the secondary pile engaging devices. Preferably, the secondary pile engaging devices are interposed between the primary pile engaging devices, such that along the circumference of the pile holder, the primary engaging devices alternate with the secondary engaging devices. This is for example beneficial when a surface feature of the pile is aligned with one of the primary pile engaging devices, preventing that pile engaging device from engaging the pile. In such a situation, the secondary pile engaging devices can be used, instead of the primary pile engaging devices, to engage and rotate the pile over a first angle. Once the pile has been rotated by the secondary pile engaging devices, the surface feature may have been moved sufficiently for the primary pile engaging devices to engage the pile and rotate the pile over a second angle.

In an embodiment each track structure supports at least one primary pile engaging device and at least one secondary pile engaging device. In an alternative embodiment, each track structure supports a primary pile engaging device or a secondary pile engaging device.

In an embodiment, one or more track structures are connected to each other, which allows for the pile engaging devices to be moved from one track structure to another, connected, track structure. This for example may also allow for one or more pile engaging devices to be moved to a single track structure temporarily, for example when the pile holder is supported in an inboard storage position.

In an embodiment, the track structures from a ring shaped track, extending along the full inner circumference of the pile holder, the ring shape track supporting the primary pile engaging devices and preferably supporting the secondary pile engaging devices

In an embodiment, the track structures from a first ring shaped track and a second ring shaped track, both the first track and the second extending along the full inner circumference of the pile holder.

In an embodiment, the primary pile engaging devices, and preferably the secondary pile engaging devices, each comprises a suspension arm, each suspension arm having an engaging end and a pivot end, wherein the suspension arm is at the pivot end pivotable supported, such that the suspension arm is pivotable about a pivot axis, preferably the pivot end being a top end of the suspension arm and the pivot axis preferably being a horizontal pivot axis, and wherein each suspension arm is at the engaging end provided with one or more pile engaging elements. In an embodiment, each pile engaging device comprises a suspension arm actuator to position the suspension arm at different angular positions about the pivot axis to allow simultaneous engagement of all pile engaging devices with corresponding piles having different diameters when the first and second yaw are in their closed positions.

In a further embodiment, the suspension arm actuator is provided between the chassis and the suspension arm.

The above embodiments allow to adjust for changes in diameter of the pile being lowered through the pile passage while the pile engaging devices engages the outer surface of the pile. The suspension arm actuators may be controlled using a diameter adjustment system configured to keep pile centre fixed and allow pile engaging elements, e.g. rollers to translate substantially perpendicular to pile surface. An advantage thereof is that no slipping occurs over coating for conical sections of a pile.

In an embodiment, the pile holder with the first yaw and the second yaw in the closed position forms an annular structure and the track structures extend along the inner circumference of the annular structure, preferably the complete inner circumference.

In an embodiment, the one or more pile engaging elements comprise pile guiding rollers, preferably comprise two or more pile guiding rollers supported in a carrier that is pivotably connected to a support end of a suspension arm to pivot about a carrier pivot axis, which suspension arm in turn is pivotable about a suspension arm pivot axis, wherein the pile guiding rollers each have an axis of rotation, wherein the pile guiding rollers are supported by the carrier such that their axis of rotation extend parallel to the carrier pivot axis, and wherein preferably the carrier pivot axis extends parallel to the suspension arm pivot axis.

An advantage of the pile guiding rollers is that the pile engaging device is enabled to follow the changes in the diameter of the pile being lowered through the pile passage while the pile engaging device engages the outer surface of the pile

In an embodiment, the base structure, the first jaw and the second jaw each support at least one pile engaging device.

According to the second aspect, the invention furthermore provides a pile holding system to be mounted on a deck of a vessel, e.g. for installation of a pile adapted to support an offshore wind turbine, which pile holding system is configured to support the pile in an upright position at a pile installation location next to the vessel, the pile holding system comprising:

- a pile holder according to the second aspect of the invention, and

- a pile holder support system to be mounted on the deck of the vessel, wherein the support system supports the pile holder at the base structure, preferably moveably supports the pile holder at the base structure.

In an embodiment, the pile holder support system is configured to move the pile holder, preferably in a first direction, which first direction, when the pile holding system is mounted on the deck of a vessel is substantially parallel to the deck of the vessel, between an inboard position and an outboard position.

In an embodiment, the pile holder, when in the outboard position, is located outside a contour of the vessel, for holding the pile in the upright position at the installation location, and wherein the pile holder, when in the inboard position with the first and second jaw in the open position, is located within the contour of the vessel.

According to the second aspect, the invention furthermore provides a method for rotating a pile to be driven in the sea bottom at a pile installation location, the method comprising the steps;

- positioning a vessel provided with a pile holder according to the second aspect of the invention next to the pile installation location, and supporting the pile holder in an outboard position for engaging the pile;

- using a crane to support the pile in a vertical position in the pile holder;

- engage the pile with the primary pile engaging devices supported on the track structures provided on the pile holder; and

- moving the primary pile engaging devices in a forward direction along the track structures, and thus rotating the pile about its longitudinal axis.

The present invention also relates to a pile holder accord to the second aspect, the pile holder comprising:

- a base structure, e.g. adapted to be mounted to a support frame as described herein, e.g. to be pivotally mounted to the support frame to pivot relative to the support frame about base pivot axis between a substantially vertical orientation and a substantially horizontal orientation, - an annular structure configured to extent about a passage for a pile to be handled by the pile holder, the annular structure being supported by the base frame or the base frame structure forming a section of the annular structure,

wherein the annular structure comprises two semi-circular jaws, each pivotally connected at an inner end thereof and pivotal about a pivot axis between a closed position, wherein outer ends of the jaws join up, and an opened position,

wherein the annular structure is provided with a circular support track structure that carries multiple pile engaging devices, e.g. with pile guiding rollers, e.g. four or more, here six, of such devices,

wherein, preferably, one or more, e.g. all, of the pile engaging devices are movable along the circular support track structure, at least over an arc segment of the circle, so as to allow for adaptation of the angular position of the pile engaging devices relative to the passage for the pile.

Thus, the pile holder may comprise an annular structure defined by two semi-circular yaws, which yas are provided with pile engaging devices, e.g. the primary pile engaging devices.

In an embodiment each pile engaging device carries one or more, e.g. a pair of two, pile guiding rollers in a movable manner to allow for adjustment of the radial position of the rollers relative to the passage for the pile. For example each pile engaging device comprises a suspension arm that is pivotal about a horizontal axis, here as preferred from a top end of the arm, relative to a chassis of the device that is supported on the track structure.

In an embodiment a suspension arm actuator, e.g. a hydraulic cylinder, is provided between the chassis and the arm to adjust the radial position of the roller(s).

In an embodiment each chassis here is provided with a motorized drive adapted to move the chassis along, possibly a section of, the circular track structure so as to adjust the angular position of the device.

A further method comprises the steps;

- after rotating the pile over a first angle, engaging the pile with secondary pile engaging devices and releasing the pile with the primary engaging devices; and

- moving the primary pile engaging devices in a backward direction along the track structures;

- engage the pile with the primary pile engaging devices and release the pile with the secondary pile engaging devices; and

- moving the primary pile engaging devices in a forward direction along the track structures, and thus rotating the pile about its longitudinal axis. An alternative method comprises the steps;

- after rotating the pile over a first angle, engaging the pile with secondary pile engaging devices and releasing the pile with the primary engaging devices; and

- moving the secondary pile engaging devices in a forward direction along the track structures, and thus rotating the pile about its longitudinal axis;

- moving the primary pile engaging devices in a backward direction along the track structures;

- engage the pile with the primary pile engaging devices and release the pile with the secondary pile engaging devices; and

- moving the primary pile engaging devices in a forward direction along the track structures, and thus rotating the pile about its longitudinal axis.

It will be appreciated that the benefits of the pile holder according to the second aspect of the invention can be combined with the pile holding system according to the first aspect of the invention, as well as with the pile holding systems according to the other aspects of the invention. Equally all embodiments of the pile holder according to the second aspect of the invention, as well as each and every other technical feature addressed with reference to the other aspects of the present invention can be combined, e.g. in various combinations of such features with the pile holder according to the invention.

Thus, for example the pile holder according to the second aspect of the invention can be combined with a pile holding system according to the fourth aspect of the invention, i.e. a pile holding system comprising a vertical support frame, the vertical support frame extending between a lower end of the vertical support frame, and an upper end of the vertical support frame wherein the vertical support frame is configured to be moved in a vertical direction relative to the mount between a lowered position and a raised positon, and to be secured to the mount in the lowered position and in the raised position, and wherein the vertical support frame in the proximity of the lower end thereof supports the pile holder.

The present invention also relates to a pile holder according to the second aspect, the pile holder comprising a base structure, e.g. adapted to be mounted to a support frame as described herein, e.g. to be pivotally mounted to the support frame to pivot relative to the support frame about base pivot axis between a substantially vertical orientation and a substantially horizontal orientation,

According to a third aspect of the invention, there is provided a pile holding system to be mounted on a deck of a vessel, e.g. for installation of a pile adapted to support an offshore wind turbine, which pile holding system is configured to support the pile in an upright position at a pile installation location next to the vessel, the pile holding system comprising:

a pile holder comprising a base structure, a first jaw and a second jaw, the first jaw and the second jaw each extending between an inner end and an outer end, and wherein the first and second yaw are pivotable connected at the inner end thereof to a respective pivot part of the base structure to pivot about a yaw pivot axis between a closed position, in which the pile holder defines a pile passage for the pile held in the pile holder, and an open position, to allow the pile to be received in, or to be removed from, the pile holder in a lateral direction;

a plurality of pile engaging devices, wherein the base structure, the first jaw and the second jaw each support at least one pile engaging device, the engaging devices each comprising one or more pile engaging elements, e.g. each comprising one or more pile guiding rollers for engaging the pile in the pile passage; and

a pile holder support system to be mounted on the deck of the vessel, wherein the support system moveably supports the pile holder, and which support system is configured to move the pile holder in a first direction between an inboard position and an outboard position,

wherein the pile holder, when in the outboard position, is located outside a contour of the vessel, for holding the pile in the upright position at the installation location, and wherein the pile holder, when in the inboard position is located within the contour of the vessel.

In an embodiment, the pile holder support system is configured to move the pile holder into a pickup position, which pickup position is the pile holder is located within the contour of the vessel and above an accessory storage of the vessel, to enable an accessory, for example a vertical collapsible noise mitigation screen, stored in the accessory storage, to be attached to the pile holder, preferably to be attached to the base structure, the first jaw and the second jaw of the pile holder.

Thus, the pile holder support system is configured to enable the pile holder to be located above an accessory located on the vessel, for example on the deck of the vessel. This facilitates mounting an accessory to the pile holder, in particular on full sea without the need of a second vessel for positioning the accessory below the pile holder.

With a pile holding system according to the invention, both accessory and pile holder are located on the same vessel, thus there is no relative movement between accessory and pile holder which highly facilitates mounting and demounting the accessory. For example, such an embodiment allows for positioning the pile holder above a vertical collapsible noise mitigation screen, the latter being stored on the vessel. During storage, the accessory can be checked, repairs can be made if required, etc. Once use of the accessory is required, the pile holder is moved above the accessory, which can be attached to the pile holder and subsequently lifted overboard by the pile holder. Thus there is no need for example a second vessel to position the accessory below the pile holder and one or more cranes to lift the accessory form the second vessel to enable it to be mounted to the pile holder.

In an embodiment the pile holder is provided with dedicated supports, e.g. brackets or a support frame, for mounting an accessory. In a further embodiment, the pile holder is provided with guides for lifting wires, for example brackets or sheeves, the lifting wires being used for positioning an accessory adjacent the pile holder and/or for supporting the pile accessory during use of the pile holder.

In an embodiment, the pile holder is provided with one or more winches, located on the pile holder and/or the wires being guided from those winches via the pile holder, for lifting an accessory from the accessory storage, for example the deck of the vessel, towards the pile holder, to enable mounting the accessory to the pile holder and/or for supporting the accessory during use of the pile holder.

In an embodiment, the pile holder support system comprises a base track, the base track extending in the first direction, a base track carriage, the base track carriage supporting the pile holder, and a base track carriage drive, for moving the base track carriage along the base track.

The base track is mounted on the deck of the vessel, and allows for moving the pile holder from the inboard position within the contour of the vessel to the outboard position outside the contour of the vessel. The single track configuration allows for a simple and clean installation on the vessel, in particular when the base track comprises a single beam structure to be mounted on the deck of the vessel. In such an embodiment, the pickup location is located at a side of the base track. Preferably, the single beam structure supports the pile holder above the deck of the vessel at a height that allows for storing accessories on the deck of the vessel, the deck below the storage position of the pile holder being the accessory storage location. In a further embodiment, the pile holder can be positioned on opposite sides of the single track above the deck of the vessel and/or above a accessory storage. Thus, for example the deck at one side of the base track can be used to store an accessory between use, while the deck on the other side of the base track can be used for inspection and maintenance of the pile holder.

In an alternative embodiment, the support system comprises a first base track and a second base track, the first base track and the second base track extending in the first direction, a first base track carriage and a second base track carriage, the base track carriages supporting the pile holder, and a first base track carriage drive and a second base track carriage drive, for moving the base track carriages along the first and the second base track respectively. This embodiment still allows for a small footprint, in particular when each base track comprises a single beam structure to be mounted on the deck of the vessel, and combines tis with a more robust support. Preferably, the pickup location is located between the first base track and the second base track, which allows for the pile holder being supported on both sides while mounting the accessory.

It is noted that the invention provides a pile holding system of which the pile holder can be mounted on the deck of a vessel, and of which the pile holder can be positioned above the deck of the vessel. The latter not only facilitates mounting and demounting accessories on full sea, but also facilitates access to the pile holder, for example for inspection, maintenance, etc. Furthermore, it allows for use of the pile holder to lift accessories from an on board position to an overboard position. This reduces the need to use a crane, which can thus be used for other activities.

In an embodiment, the pile holder support system is configured to move the pile holder in a second direction, which second direction preferably is perpendicular to the first direction, and the pile holding system further comprises a motion control system, which motion control system is configured to move the pile holder, when in the outboard active position, relative to the vessel in the first direction and in the second direction to push and/or keep the pile in the upright position at the installation location while the pile is being lowered towards the sea floor and/or after the pile has landed on the sea floor.

Thus, the pile holder support system is used for guiding the pile, but also for actively keeping the pile in the upright position while the pile is lowered towards the sea floor and/or while the pile is driven into the sea floor. Movement of the pile holder relative to the vessel allows for the pile holder to compensate for drift of the vessel relative to the pile installation location. Also, in particular while the pile is being lowered towards the seafloor, the movement of the pile holder relative to the vessel can be used to compensate for the pile deviating from the upright position, the deviation for example being caused by the position of the crane supporting the pile while being lowered towards the seafloor, by sea currents, by composition of the top layer of the sea floor in which the pile is landed, etc.

In an embodiment the motion control system is configured to keep the pile holder at a predetermined gps location, for example the location at which the pile guided by the pile holder in an upright position was landed on the seafloor.

In an embodiment of a pile holding system according to the invention, the support system comprises a secondary track, the secondary track extending in the second direction and perpendicular to the base track or to the first base track and the second base track.in a further embodiment, the secondary track base comprises a single beam structure supported by the base track carriage or the first base track carriage and the second base track carriage.

Thus, the pile support system comprises a track with a T-shaped or a H-shaped lay out respectively, the secondary track being moveable relative to the deck mounted base track or base tracks. This provides for a robust pile support system with a small footprint that furthermore can be mounted on the deck of a vessel without requiring significant redesign of the vessel or requiring lots of deck space.

The invention furthermore provides a pile holding system comprising a motion control system that comprises a pile monitoring system, for example comprising camera’s and or lasers, which pile monitoring system is configured to monitor the orientation of the pile held by the pile holder in the pile passage, which pile monitoring system is linked to the motion control system.

Providing the pile holding system with a motion control system configured to move the pile holder while taking into consideration this kind of data allows for a more accurate installation. Preferably motion control system is configured to use the information to actively control the pile holder while the pile is lowered towards the sea floor and/or while the pile is driven into the sea floor.

The invention furthermore provides a pile holding system of which the motion control system is configured to be linked to a crane monitoring system of aa crane to be used to manipulate the pile and/or lower the pile towards the sea floor, the crane monitoring system providing information regarding the orientation and/or speed of a hoisting device of a crane supporting the pile at a top end thereof.

Providing the pile holding system with a motion control system configured to move the pile holder while taking into consideration this kind of data allows for a more accurate installation. Preferably motion control system is configured to use the information to actively control the pile holder while the pile is lowered towards the sea floor and/or while the pile is driven into the sea floor.

In a further embodiment, the motion control system is configured to control hoisting device of the crane to move the pile, or at least the top end thereof, into a particular position and/or keep the pile or at least a top end thereof at a particular position relative to the pile holder, preferably while the crane is used to lower the pile towards the sea floor.

The invention furthermore provides a pile holding system of which the motion control system comprises, or is configured to be linked to, a vessel monitoring system, the vessel monitoring system providing information regarding the location and/or orientation and/or speed of the vessel supporting the pile holding system.

Providing the pile holding system with a motion control system configured to move the pile holder while taking into consideration this kind of data allows for a more accurate installation. Preferably motion control system is configured to use the information to actively control the pile holder while the pile is lowered towards the sea floor and/or while the pile is driven into the sea floor.

In a further embodiment, the motion control system is configured to control propulsion of the vessel to move the pile holder into a particular position and/or keep to the pile holder at a particular position. Thus, the motion control system is not limited to moving the pile holder within the window of movement provided by the pile holder support system.

The invention furthermore provides a pile holding system of which the motion control system comprises, or is configured to be linked to, a wave monitoring system, which wave monitoring system for example uses radar to monitor incoming waves, to enable the motion control system to use this information to move the pile holder into a particular position and/or keep to the pile holder at a particular position. Providing the pile holding system with a motion control system configured to move the pile holder while taking into consideration this kind of data allows for a more accurate installation. Preferably motion control system is configured to use the information to actively control the pile holder while the pile is lowered towards the sea floor and/or while the pile is driven into the sea floor.

In an embodiment, the yaw pivot axis of the first yaw and the yaw pivot axis of the second yaw define a plane, wherein the outer ends of the first and second yaw are located at a side of the plane in the closed position, and wherein the outer ends of the first and second yaw are located in the plane or at an opposite side of the plane in the open position. Such an embodiment, allows fro positioning the pile holder within the contour of the vessel close along the contour of the vessel.

In addition, or as an alternative, the pile holder support system is configured to move the pile holder into an inboard position, i.e. within the contour of the vessel, with the yaws in the closed position. This may be the preferred position of the yaws when mounting an accessory to the pile holder.

In an embodiment, the pile holding system further comprises an actuation system configured to pivot the first yaw between its closed position and its open position and configured to pivot the second yaw between its closed position and its open position.

In an embodiment, in the inboard position, substantially the entire pile holding system is located within the contour of the vessel. An advantage of being able to open and fully retract the pile holder is that large objects, e.g. such as a pilling hammer or transition piece can easily pass the pile holding system. This also allows for positioning and/or upending the pile adjacent the vessel without the risk of the pile coming into contact with the pile holder, possibly damaging the pile holder or an accessory supported by the pile holder.

In an embodiment, the pile is manipulated by a crane, mounted on the vessel supporting the pile holding system, adjacent the vessel. Only when the pile is supported in a upright position by the crane, the pile holder is moved from its position within the contour of the vessel to a position outside the contour of the vessel for receiving the pile.

In an embodiment, the yaws of the vessel are opened to engage the pile in a lateral direction. As alternative, the yaws are closed, and the pile is lowered by the crane into the pile passage defined by the yaws. In an embodiment, the pile holder in the outboard position and in the inboard position has a horizontal orientation, and wherein the support system is configured to move the pile holder between the inboard position and the outboard position while maintaining the horizontal orientation of the pile holder.

In an embodiment, the first direction is a substantially horizontal direction. During movement of the pile holder between the inboard position and the outboard position, the pile holder may be held in the same orientation, meaning that the pile holder is not pivoted up or down, or tilted.

In an embodiment, the base structure of the pile holder is pivotally mounted to the support system, to enable the pile holder to be pivoted relative to the support system about a base structure pivot axis between a substantially vertical orientation and a substantially horizontal orientation. In this example it is envisaged that this tilting is only in view of sailing with the vessel, mooring in a port, etc., as it is envisaged that a pile is hoisted by a crane and placed in vertical orientation before engagement thereof by the pile holder.

As was already noted above, in an embodiment, the support system is configured for moving the pile holder in a second direction, which preferably is perpendicular to the first direction, between a first outer position and a second outer position, to allow the support system to position the pile holder in a horizontal plane relative to the vessel.

In an embodiment, the support system comprises a base track, preferably a base track to be mounted on the deck of the vessel, extending in the first direction, and a base carriage for movement along the track, wherein the base carriage is configured to support the base structure of the pile holder, and wherein the base structure is moveable, preferably in a second direction perpendicular to the first direction, between a first outer position and a second outer position, to allow the support system to position the pile holder in a horizontal plane relative to the vessel.

Alternatively, the base track may extend in the second direction and the base structure of the pile holder is moveable relative to the base carriage in the first direction in such an embodiment, the base carriage support a secondary track, the pile holder being moveable along said secondary track. In an embodiment, the base carriage comprises a U-shaped carriage frame, the carriage frame comprising two legs, each leg extending along a track, preferably each leg extending along a rail of the track, and at least one cross section connecting the legs of the frame. The at least one cross section preferably connects the legs at an end of the legs facing the pile holder, and the at least one cross section preferably supports the base structure.

In an embodiment, the base carriage comprises a l-shaped or T-shaped carriage frame, the carriage frame comprising a part corresponding to the vertical bar of the l-shape or T-shape, wherein said part extends along a track, and wherein another track is provided at a free end of the l-shaped carriage frame or the part of the carriage frame corresponding to the horizontal bar of the T-shape, and wherein the base structure is moveable connected to said other track.

In an embodiment, the pile support system further comprises a motion control system, which control system is configured to provide active motion compensation in the horizontal plane while the pile holder supports the pile in the upright position at the installation location next to the vessel to compensate for movement of the vessel relative to the pile installation location.

In an embodiment, the pile support system further comprises a monitoring system that is configured to monitor the position and/or orientation of the pile while the pile is being loaded into the pile holder and/or while the pile holder supports the pile in the upright position at the pile installation location next to the vessel, and a control system that is configured to control movement of the first and second yaw and the support system.

In an embodiment, the control system is configured to move the pile away from the vessel by moving the pile holder towards and/or past the outboard position, for example when the monitoring system indicates that the position and/or orientation of the pile exceeds a predetermined first value.

In an embodiment, the control system is configured to automatically move the first and second yaw to their respective open positions to avoid interference between the pile on the one hand and the first and second yaw on the other hand.

In other words, the control system may be configured to push the pile away from the vessel by moving the pile holder towards and/or past the outboard position when the jaws of the pile holder are in the open position, and/or to automatically open the jaws of the pile holder and moving the pile holder towards and/or past the outboard position, when the position and/or orientation of the pile exceeds a predetermined value.

In such embodiments, the support system is preferably configured to move the pile holder beyond the outboard position, in particular when the pile is not yet driven into the sea floor. Preferably, the control system is configured to encompass information regarding the installation of the pile, more in particular is able to monitor, e.g. using the monitoring system, if the pile is already driven into the sea floor and preferably only allows for pushing the pile away from the vessel when the pile is not yet mounted in the sea floor, and/or is no longer supported by a crane, and/or is configured to remove a connection between the pile and a crane supporting the pile.

In an embodiment, the control system is configured to move the pile holder away from the pile by moving the pile holder towards the inboard position when the monitoring system indicates that the position and/or orientation of the pile exceeds a predetermined second value. The first and second value may be the same. This embodiment may particularly be useful when the pile is already at least partially driven into the sea floor and pushing the pile away is no longer possible, feasible or desired.

The monitoring system may further be configured to monitor if the pile is already at least partially driven into the sea floor, so that the control system activates the above embodiment, i.e. function, when the pile is at least partially driven into the sea floor. Manual activation of this function is of course also possible.

In an embodiment, the base section and the first and second yaw each extend along a 120 degree arc-shaped trajectory. The base section and the first and second yaw thus each may form one third of the circumference of the pile holder when the first and second yaw are in the closed position.

In an embodiment, the first jaw and the second yaw and preferably the base structure each have a semi-circular configuration to provide the pile holder with an annular configuration having a circular inner circumference when the jaws are in the closed position.

In an embodiment, when the first yaw and the second yaw are in the closed position, the outer ends of the jaws join up, and wherein preferably a locking mechanism is provided to lock the first yaw and the second yaw in their closed positions, e.g. by connecting the outer ends to each other. In an embodiment, the pile holder comprises a fender structure, preferably mounted on the base structure, for rough positioning of the pile and/or collision prevention between pile and other pile holder portions.

In an embodiment, each pile engaging device comprises a suspension arm, each suspension arm having an engaging end and a pivot end, wherein the pivotable suspension arm is at the pivot end pivotable supported, such that the suspension arm is pivotable about a pivot axis, preferably the pivot end being a top end of the suspension arm and the pivot axis preferably being a horizontal pivot axis, and wherein each suspension arm is at the engaging end provided with one or more pile engaging elements.

In an embodiment, each pile engaging device comprises a suspension arm actuator, preferably a hydraulic cylinder, to position the suspension arm at different angular positions about the pivot axis to allow simultaneous engagement of all pile engaging devices with corresponding piles having different diameters when the first and second yaw are in their closed positions.

The above embodiments allow to adjust for changes in diameter of the pile being lowered through the pile passage while the pile engaging devices engages the outer surface of the pile. The suspension arm actuators may be controlled using a diameter adjustment system configured to keep pile centre fixed relative to pile holder, and allow pile engaging elements, e.g. rollers to translate substantially perpendicular to pile surface. An advantage thereof is that no slipping occurs over coating for conical sections of a pile.

In an alternative embodiment, the pile engaging devices comprise a suspension arm extending in a radial direction relative to the pile passage, each suspension arm having an base end, located radially outward at the yaw or base structure of the jaw, and an enaging end, located radially inward, wherein the suspension arm is at the engaging end provided with one or more pile engaging elements.

Such a radial suspension arm may comprise an axial actuator, for example a hydraulic cylinder or spindle, for moving the engaging end in the radial direction, i.e. towards the pile, and thus for pushing a pile engaging element against the pile, and away from the pile supported in the pile passage, and thus to disengage the pile, for example to allow for example a bracket or port provided on or in the pile surface to pass the pile engaging element. In an embodiment, the pile engaging devices comprise a chassis, wherein the first yaw and the second yaw, and preferably the base structure, each comprise a track structure, e.g. a rack or rail section, extending along a longitudinal direction of the respective first yaw, second yaw or base structure, wherein the chassis of each of the pile engaging devices is moveably supported on one of the track structures, and wherein each chassis is provided with a drive adapted to move the chassis, and thus the pivotable suspension arm or the radial suspension arm supported b the chassis, along the track structure.

In an embodiment, the suspension arm actuator is provided between the chassis and the pivotable suspension arm.

In an embodiment, each pile engaging device is provided with its own hydraulic power source for power a suspension arm actuator for moving the engaging end of the suspension arm relative to the chassis towards and away form the pile and/or to power a drive for moving the chassis along the track structure. The hydraulic power source is preferably located on the chassis. As an alternative, the hydraulic power source is located on the base structure or the yaw supporting the particular pile engaging device.

In an embodiment, the pile holder with the first yaw and the second yaw in the closed position forms an annular structure and the track structures extend along the inner circumference of the annular structure. In a further embodiment, the combined track structures extend along the complete inner circumference of the pile holder.

In an embodiment, the pile holding system further comprises a control system configured to control the drives of the pile engaging devices, or a selection of pile engaging devices, and to drive the pile engaging device in unison along the track structures. In a further embodiment, the pile engaging devices are configured to be driven along the track structures while engaging the pile in the pile passage, to rotate the pile about a longitudinal axis of the pile.

Thus, in such an embodiment, the pile engaging devices can be used for positioning and guiding the pile while the pile is being lowered towards the sea floor and/or is driven into the seafloor, and for rotating the pile about its longitudinal axis. Typically, in prior art monopile grippers one or more dedicated pile rotation devices are provided. Use of these dedicated devices requires disengagement of the pile engagement devices, which would otherwise keep the pile fixed in position. With the embodiment according to the invention discussed above there is no separate pile rotating device, thus, the pile engaging devices can maintain contact with the pile when the pile is to be rotated.

In a further embodiment, the pile holding system comprises at least four, preferably at least six, pile engaging devices, and wherein the control system is configured to rotate the pile about its longitudinal axis over a first angle using a first set of pile engaging devices, and to subsequently rotate the pile about its longitudinal axis over a second angle using a second set of pile engaging devices, the pile engaging devices each belonging to a single set of pile engaging devices.

In an embodiment, the one or more pile engaging elements comprise pile guiding rollers, preferably comprise two or more pile guiding rollers supported in a roller carrier that is pivotably connected to a support end of a suspension arm, the suspension arm being a pivotably movebale suspension arm or an axially movebale suspension arm, to pivot about a carrier pivot axis. In an embodiment, the pile guiding rollers each have an axis of rotation, wherein the pile guiding rollers are supported by the roller carrier such that their axis of rotation extend parallel to the roller carrier pivot axis.

In an embodiment, the suspension arm is a pivotably supported suspension arm, which suspension arm is pivotable about a suspension arm pivot axis., and the rller carrier pivot axis extends parallel to the suspension arm pivot axis.

An advantage of the pile guiding rollers is that the pile engaging device is enabled engage the pile with multiple rollers and to follow the changes in the diameter of the pile being lowered through the pile passage while the pile engaging device engages the outer surface of the pile

In an embodiment, the track structures are semi-circular track structures.

The third aspect of the invention furthermore provides a vessel, the vessel comprising a pile holding system according to invention mounted on a deck of the vessel, e.g. for installation of a pile adapted to support an offshore wind turbine, which pile holding system is configured to support the pile in an upright position at a pile installation location next to the vessel.

In an embodiment, the vessel comprises a pile holding system mounted on a deck of the vessel, e.g. for installation of a pile adapted to support an offshore wind turbine, which pile holding system is configured to support the pile in an upright position at a pile installation location next to the vessel, the pile holding system comprising:

a pile holder comprising a base structure, a first jaw and a second jaw, the first jaw and the second jaw each extending between an inner end and an outer end, and wherein the first and second yaw are pivotable connected at the inner end thereof to a respective pivot part of the base structure to pivot about a yaw pivot axis between a closed position, in which the pile holder defines a pile passage for the pile held in the pile holder, and an open position, to allow the pile to be received in, or to be removed from, the pile holder in a lateral direction;

a plurality of pile engaging devices, wherein the base structure, the first jaw and the second jaw each support at least one pile engaging device, the engaging devices each comprising one or more pile engaging elements, e.g. each comprising one or more pile guiding rollers; and

a support system mounted on the deck of the vessel, wherein the support system moveably supports the pile holder at the base structure, and which support system is configured to move the pile holder in a first direction between an inboard position and an outboard position,

wherein the pile holder, when in the outboard position, is located outside the contour of the vessel, for holding the pile in the upright position at the installation location, and wherein the pile holder, when in the inboard position with the first and second jaw in the closed position, is located within the contour of the vessel.

In an embodiment, the vessel has a longitudinal axis, the axis extending between a bow and an aft of the vessel, and wherein the pile holder when moved in the first direction is moved perpendicular to the longitudinal axis of the vessel.

In an embodiment, the pile holding system is arranged at a side of the vessel to hold a pile outside the contour of the vessel seen from above at a port or starboard side of the vessel.

In an alternative embodiment, the pile holding system is arranged at a stern of the vessel to hold a pile outside the contour of the vessel seen from above at a stern side of the vessel.

In an embodiment, the vessel further comprises a crane to handle a pile, wherein the crane preferably is arranged adjacent at a stern of the vessel in line with a centre of gravity of the vessel.

In an embodiment, the pile holding system is arranged adjacent the crane. In an embodiment, the vessel further comprising a deck, the deck providing a storage location, which storage location allows to store a pile driving mechanism to drive a pile into a sea floor and/or one or more piles, and/or a pile holder accessory in the accessory storage.

In an embodiment, the vessel further comprises a storage location at a stern of the vessel at a side of the crane opposite to the side where the pile holding system is arranged, which storage location allows to store a pile driving mechanism to drive a pile into a sea floor.

In an embodiment, the vessel comprises deck space to store piles in a horizontal orientation parallel to the longitudinal axis of the vessel.

In an embodiment, the vessel comprises a pick up position for the pile holder, and, when in the pickup position, the entire pile holding system is located within the contour of the vessel, preferably with the first jaw and the second jaw in the closed position.

In an embodiment of the vessel, the pile holder in the outboard position and in the inboard position has a horizontal orientation, and the support system is configured to move the pile holder between the inboard position and the outboard position while maintaining the horizontal orientation of the pile holder.

In a further embodiment, the first direction is a substantially horizontal direction, more in particular is a direction substantially parallel to a deck surface of the vessel.

In an embodiment, the pile holder support system comprises a motion control system, which motion control system is configured to move the pipe holder in a first and a second direction relative to the vessel to provide active motion compensation in the horizontal plane while the pile holder supports the pile in the upright position at the installation location next to the vessel to compensate for movement of the vessel relative to the pile installation location.

In a further embodiment, the motion control system comprises a monitoring system that is configured to monitor the orientation of the pile while the pile holder supports the pile at the pile installation location next to the vessel, and a control system that is configured to control movement of the first and second yaw and the support system. The invention further relates to a method for installation of a pile adapted to support an offshore wind turbine, wherein at least partially use is made of a vessel according to the invention, and wherein the method comprises the following steps:

a) transporting a pile to the offshore pile installation location;

b) moving the pile holder from the inboard position to the outboard position, with the first yaw and the second aw in the open position;

c) lifting the pile at an upper end thereof, and positioning the pile in the pile holder;

d) lowering the pile to the sea floor; and

e) driving the pile into the sea floor.

In a further method according to the invention, step b. further comprises moving the pile holder from a pickup position to the outboard position, preferably after mounting an accessory stored in an accessory storage below the pickup positon to the pile holder, and deploying the accessory during step d and/or step e.

In a further method according to the invention, step d. and/or step e. comprises using a motion control system to move the pile holder relative to the vessel in a first direction and in a second direction to push and/or keep the pile in the upright position at the installation location while the pile is lowered towards the sea floor and/or while the pile, or at least a first section of the pile, is driven into the sea floor respectively.

In a further method according to the invention, step d. and/or step e. further comprises using a pile monitoring system, for example comprising camera’s and or lasers, to monitor the orientation of the pile held by the pile holder in the pile passage, which pile monitoring system is linked to the motion control system.

In a further method according to the invention, step d. and/or step e. further comprises using a crane monitoring system to provide information regarding the orientation and/or speed of a hoisting device of a crane supporting the pile at a top end thereof to the motion control system. A further method comprises using the motion control system to control the hoisting device of the crane to move the pile, or at least the top end thereof, into a particular position and/or keep the pile or at least a top end thereof at a particular position relative to the pile holder.

In a further method according to the invention, step d. and/or step e. further comprises using a vessel monitoring system to provide the motion control system with information regarding the location and/or orientation and/or speed of the vessel, and preferably use the motion control system to control propulsion of the vessel to move the pile holder into a particular position and/or keep to the pile holder at a particular position.

In a further method according to the invention, step d. and/or step e. further comprises using a wave monitoring system, which wave monitoring system for example uses radar to monitor incoming waves, to provide the motion control system with incoming wave information an preferably use to use this information to move the pile holder into a particular position and/or keep to the pile holder at a particular position.

In a further method according to the invention, during at least one or more steps, preferably all steps, the vessel is in floating condition. In a further method according to the invention, during step e. and/or step f., the pile holder is compensated for wave-induced motion of the vessel to maintain a predetermined X-Y location independent of the wave-induced motion of the vessel.

In a further method, the vessel also carries out step a.

When in floating condition, the vessel is not supported on jackup legs and preferably is not moored to a quay or the sea floor. Preferably the vessel is provided with a control system that manipulate the drive of the vessel, typically thrusters, to hold the vessel with a particular orientation at a particular GPS location. It is submitted that vessels with such a control system are as such widely known in the prior art. However, pile holding devices are typically mounted to jack up vessels, because it is easier to support a pile from a fixed vessel, i.e. a vessel supported on jack up legs.

In an embodiment, the method further comprises the step of positioning the pile relative to the installation location using the support system of the pile holding system to adjust the position of the pile relative to the vessel and optionally relative to the fixed world, i.e. the sea floor, while the pile is supported from a crane, which crane preferably is mounted on the vessel provided with the pile holding system.

In an embodiment, during step d. and or step e. the pile is held by the pile holder.

In an embodiment, step c. and/or step e. is carried out by a crane on the vessel. In an embodiment, during step d. and/or step e., the pile holder is compensated for wave- induced motion of the vessel to maintain a predetermined X-Y location independent of the wave-induced motion of the vessel.

In an embodiment, the vessel also carries out step a.

In an embodiment, positioning the pile in the pile holder, the pile being supported by a crane, is carried out such that the pile and the pile holder are moved relative to each other until the pile engages with a fender structure of the pile holder, the fender structure preferably being mounted on the base structure of the pile holder. In addition, or as an alternative, the vessel is provided with a fender structure configured to prevent a pile supported by a crane form slamming into the pile holder and/or the vessel, the fender preferably beig configured to position the crane supported pile in a position available to the pile holder for engaging the pile holder. In another embodiment, the crane supported pile is positioned by the fender and from there lowered into the pile passage of the pile holder located below the fender.

In an embodiment, the pile engages with the fender structure after positioning the pile in the pile holder, and wherein the pile engaging devices are operated to engage with the pile only after step d.

According to a fourth aspect of the invention, the pile holding system of the invention is to be mounted on a deck of a vessel, e.g. a jack up vessel, the vessel having a hull that supports the deck and that in a top view defines a contour of the vessel, wherein the pile holding system is configured to support a pile adapted to support an offshore wind turbine in an upright position at a pile installation location next to the vessel, wherein the pile holding system comprises: a, preferably annular, pile holder, the pile holder having a plurality of pile engaging devices for engaging the pile; and a support device to be mounted on the deck of the vessel, wherein the support device movably supports the pile holder, and is configured to support the pile holder in an outboard holding position, to support the pile in the upright position at the pile installation location next to the vessel, in which holding position the pile holder is outside the contour of the vessel, and in an inboard storage position, in which storage position the pile holder is substantially within the contour of the vessel, wherein the support device comprises: a track, extending in a linear direction between a support end thereof, to be located in the proximity of the contour of the vessel, and a storage end thereof, to be located at a distance from the contour of the vessel;

a cart, to be mounted on the track, for movement along the track between a support position in proximity of the support end of the track, and a storage position in proximity of the storage end of the track, wherein the cart at a front end thereof is provided with a mount; and

a vertical support frame, the vertical support frame extending between a lower end of the vertical support frame, and an upper end of the vertical support frame,

wherein the vertical support frame is configured to be moved in a vertical direction relative to the mount between a lowered position and a raised positon, and to be secured to the mount in the lowered position and in the raised position, and

wherein the vertical support frame in the proximity of the lower end thereof supports the pile holder, wherein the support device, when mounted on the deck of the vessel, enables: by movement of the cart with the vertical support frame in the raised position, the pile holder to be moved substantially parallel to the track over a distance similar to at least an inside diameter of the pile holder, preferably similar to at least an outside diameter of the pile holder, between the storage positon, in which storage position a vertical projection of the pile holder is located substantially within the contour of the vessel, and a boarding position, in which boarding position a vertical projection of the pile holder is located substantially outside the contour of the vessel, and by movement of the vertical support frame between the raised and the lowered position, the pile holder to be moved substantially perpendicular to the track over a distance similar to at least a height of the pile holder, preferably at least three times the height of the pile holder, between the boarding position, in which boarding position a horizontal projection of the pile holder is located above the deck of the vessel, and the holding position, in which holding position a horizontal projection of the pile holder is located below the deck of the vessel. The invention is based on the insight that a holding position of the pile holder close to the side of the vessel and below the deck of the vessel may allow for a compact pile holding system and for efficient installation of the pile. The invention is further based on the insight that the combination of linear horizontal and vertical movement of the pile holder allows for efficient movement of the pile holder between a holding position and a storage position, and thus for a compact support device.

The support device of the pile holding system according to the invention enables the pile holder to be moved relative to the deck of the vessel from the storage position, in which the pile holder is supported above the deck of the vessel and within the contour of the vessel, to the holding position, in which the pile holder is supported below the deck and outside the contour of the vessel. The track and cart enable substantially linear horizontal movement parallel to the deck of the vessel and the vertical support frame allows for substantially linear vertical movement perpendicular to the deck of the vessel. Linking the vertical support frame to the cart via a mount enables to realise the horizontal and vertical movement with a compact support device.

Thus, the invention allows for a pile holding system comprising a compact support device that is configured to efficiently move the pile holder between a storage position within the contour of the vessel and a holding position outside the contour of the vessel.

Furthermore, the invention allows for a storage position of the pile holder, in which the pile holder is located fully within a contour of the vessel. Furthermore, the pile holder is moved and stored in the position it is used in, i.e. with a horizontal configuration, in which a central axis of the pile holder extends in the vertical direction. This facilitates a quick and efficient switch between the storage position and the holding positon, because there is no need for the pile holder to be for example pivoted or folded into a tilted or upstanding position during the process.

Also, the pile holder in the storage position is supported parallel to the deck of the vessel. An additional advantage of the current invention is that, while in the storage position, the pile holder may be accessed for easy and safe maintenance and inspection. This because the pile holder and its components can be accessed and checked in the same way and in the same position that these devices are accessed and supported during use. For example a walkway provided on the pile holder to provide access to components of the pile holder during use, can also be used when the pile holder is supported in the storage position. This allows for a simple design of the pile holder. When the pile holder is in the holding position the pile holder is located below the deck and outside of the contour of the vessel. The vertical support frame may allow the pile holder to be lowered and supported relatively close to the hull of the vessel. When the pile is supported close to the hull of the vessel the components of the support device for positioning and supporting the pile holder may not have to reach very far from the vessel. This allows for a more compact and efficient support device.

Furthermore, the holding position of the pile holder being below the deck of the vessel allows for the pile to be more efficiently installed. The holding position below the deck of the vessel allows for a pile drive device, e.g. a water hammer, to drive the pile deeper into the sea floor compared to a higher holding position. A pile that is driven further into the seabed may be more stable compared to a pile that is driven less far into the seabed. Thus a low holding position may allow for more efficient driving of the pile and more stable piles, and thus e.g. more stable offshore wind turbines, after installation.

In an embodiment the support device comprises a cart drive, e.g. a rack and pinion drive or one or more winches, which cart drive is configured to move the cart along the track, and preferably thus move the pile holder between the storage position and the boarding position.

A cart drive, in particular a rack and pinion drive, may allow for precise and linear movement of the cart along the track. This may enable more precise positioning of the pile holder, which may lead to more precise installation of the pile.

In an embodiment the pile holding system is configured to, when the pile holder is in the holding position, allow for movement of the pile holder relative to the vessel, by movement of the cart along the track, in a first correction direction, which first correction direction is substantially parallel to the linear direction of the track.

When the vessel is located next to the installation location the distance between the vessel and the pile may not be exactly the distance as required by the pile holding system. To avoid having the position the vessel very precise from the pile installation location a movement along the first correction direction may be advantageous. This is especially beneficial when the vessel is a jack up vessel, which is not able to adjust its position once it is supported by its legs. Furthermore, adjusting the position of the pile holder relative to the vessel may be used to adjust the position of the pile during piling, for example to adjust for an inclination of the pile by pushing it into an upright position.

Preferably the support device comprises a cart drive, e.g. a rack and pinion drive, for precise movement of the cart. This may allow for more precise movement along the correction direction.

In an embodiment the vertical support frame is provided with a holder mount at the lower end of the vertical support frame, which holder mount moveably supports the pile holder, such that the pile holder can be moved relative to the vertical support frame in a second correction direction, which second correction direction is in a substantially horizontal plane and is substantially perpendicular to the linear direction of the track.

Movement of the vessel relative to the pile in a direction perpendicular to the linear direction of the track may be advantageous when the vessel is not precisely located next to the pile installation location along the second correction direction. Moving the pile holder in the second correction direction may be advantageous for gripping the pile with the pile holder.

Preferably the pile holder is both moveable in the first and second correction direction. This may allow the pile holder to support the pile even when the vessel is located with a slight offset compared to the ideal location of the vessel. In a further embodiment, the pile holding system is configured to continuously and instantly provide this adjustment of the position of the pile holder relative to the vessel, to compensate for movement of the vessel, e.g. due to wind and sea, relative to the pile installation location or the pile supported on the pile installation location.

When the vessel is located next to the installation location movement of the vessel, induced by e.g. the sea, may create a variable distance between the vessel and a pile in the installation location. A variable distance in the first correction direction may be

advantageously corrected by movement of the cart along the track. A variable distance in the second correction direction may be done by movement of the pile holder relative to the vertical support frame, more in particular relative to the holder mount.

In an embodiment wherein the vertical support frame is provided with a holder mount for movement of the pile holder in a second correction direction, the support device comprises a pile holder drive, e.g. a rack and pinion drive, which pile holder drive is configured to move the pile holder in the second correction direction.

Said pile holder drive, e.g. a rack and pinion drive, may be an advantageous system for moving the pile holder along the second correction direction. This may lead to precise movement along the second correction direction.

In an embodiment the vertical support frame and/or the pile holder are provided with connectors, for example openings or eyes or loops, for connecting a crane to the vertical support frame and/or the pile holder, and the vertical support frame and the pile holder are vertically moveable between the boarding position and the holding position by the crane, for example a main crane of the vessel, connected with the connectors.

Moving the vertical support frame and the pile holder between the boarding position and the holding position using a crane, for example a main crane of the vessel, may avoid the need for a separate vertical movement drive for the vertical support frame and the pile holder. This allows for a simple design of the support device, and may save weight in the pile holding system.

In an embodiment the vertical support frame is provided with:

- a first coupling device in the proximity of the lower end of the vertical support frame, which first coupling device is configured for securing the vertical support frame in the raised position to the mount of the cart; and

- a second coupling device in the proximity of the upper end of the vertical support frame, which second coupling device is configured for securing the vertical support frame in the lowered position to the mount of the cart.

When the vertical support frame is in the lowered or raised position, either for holding a pile or during storage, it may be advantageous to secure the vertical support frame in said positions. Using the first and second coupling devices may ensure that the vertical support frame does not move from its intended position.

In an embodiment, the pile holder, when in the storage position, is supported by the cart above the track. This provides the pile holding system with a minimal footprint, i.e. requires a minimum of deck space, even when the pile holder is supported within the contour of the vessel. In an embodiment, the track comprises a track beam, preferably a single track beam. A track with a single track beam may be a simple and lightweight way to provide a track for the pile holding system. It may also require minimal room on the deck of the vessel leaving more space on the deck compared to other track systems. In an alternative embodiment, the track may for example comprise two, or more, parallel tracks, the tracks supporting the cart. In yet a further embodiment, the support device comprises multiple carts, each supported on a dedicated track, which carts are each coupled with the vertical support frame.

In an embodiment the pile holder, when in the storage position, is located above the track, i.e. a vertical projection of the pile holder is located on the track and a horizontal projection of the pile holder is located above the track.

This may allow for a minimal space occupation on the deck of the pile holding system in the storage position since both the track and the pile holder occupy some of the same deck space.

In an embodiment, the track, preferably the track beam, has a width much smaller than the diameter of the pile holder. Thus, when the pile holder is supported in a storage position above the track, the pile holder extends on opposite sides beyond the track, i.e. cantilevers over the deck onto which the track beam has been mounted. This allows for the deck space adjacent the track to be used for storage of equipment, and/or to provide access to the underside of the pile holder when supported in the storage position.

In an embodiment the pile holder, when in the storage position, is supported at a distance above the track and/or the deck such that a storage space is provided between the pile holder and the track and/or deck, which storage space allows for the pile holder to support a device in the storage space, for example allows for a sound cancellation device, e.g. a foldable screen, to be mounted to the pile holder at a bottom side thereof, which foldable screen in a folded configuration can be supported by the pile holder in the storage space between the pile holder and the track.

Allowing the pile holder, when in the storage position, to be supported a distance above the deck may allow for the installation of devices below the pile holder. Such a device could be a sound cancellation device which may be used for cancelling the sound created by driving a pile in the sea bed. In addition, a pile holder located a distance above the deck may be easier to access. This could be advantageous for instance for maintenance and inspection of the pile holder. In an embodiment the first coupling device is configured for securing the vertical support frame in the raised position such that the storage space is present when the pile holder is in the storage position.

In an embodiment where the first coupling device is configured for securing the vertical support frame in the raised position, the vertical support frame is provided with a third coupling device, located between the first coupling device and the second coupling device, which third coupling device is configured for securing the vertical support frame in an intermediate raised position to the mount of the cart, in which intermediate raised position of the vertical support frame, the pile holder is supported closely adjacent the track and/or deck when in the storage position.

A third coupling device may allow for a more versatile pile holding system. For example, securing the pile holder in a position such that a sound cancellation device may be provided underneath the pile holder may be possible while in another position the pile holder may be closely adjacent the track and/or the deck. The pile holder may be moved between the positions by a crane provided on the vessel or it may be moved by a system integrated into the pile holding system such as a hydraulic system.

In an embodiment the vertical support frame comprises a guide track that interacts with the mount of the cart to vertically position and guide the vertical support frame in a substantially linear direction, while being moved between the lowered and the raised positon.

It may be advantageous when the vertical support frame comprises a guide track that interacts with the mount of the cart since such a guide track may give a particularly simple embodiment of the vertical support frame furthermore, it enables restricting the movement of the vertical support frame, when being raised or lowered, to movement along a linear trajectory.

In an embodiment the pile holding system further comprises a control system which control system is configured to provide active motion compensation, e.g. by actuating a cart drive configured to move the cart along the track and/or a pile holder drive configured to move the pile holder in a substantially horizontal plane and substantially perpendicular to the linear direction of the track, in the horizontal plane while the pile holder supports the pile in the upright position at the pile installation position to compensate for the movement of the vessel relative to the pile installation location. The vessel may move relative to the pile, for example due to heave. Such movement may be compensated by an active motion compensation system. This may be particularly

advantageous in combination with a pile holding system that is adapted to move the pile holder in a first and/or second correction direction. In such systems the active motion compensation system may control the pile holder to move along the first and/or second correction direction. This may allow for more precise and improved pile installation.

In an embodiment the pile holder comprises:

- a base structure; and

- a first jaw and a second jaw, the first jaw and the second jaw each extending between an inner end and an outer end, and wherein the first and second jaw are pivotable connected at the inner end thereof to a respective pivot part of the base to pivot about a yaw pivot axis between a closed position, in which the pile holder defines a pile passage for the pile held in the pile holder, and an open position, to allow the pile to be received in, or to be removed from, the pile holder in a lateral direction;

wherein the base structure, the first jaw, and the second jaw each support at least one of the plurality of pile engaging devices.

The open and closed position of the pile holder and the pile engaging devices may give various advantages. Opening and closing the pile holder may allow for more ways to engage a pile. If the pile is already placed in the installation position the pile holder may engage the pile in the open position, being moved towards the pile by movement of the cart along the track and/or the pile holder relative to the vertical support frame, before closing. After driving the pile, the pile holder may open to allow the pile to be disengaged. The pile engaging devices may allow for better engagement of the pile by the pile holder. Further, it may be advantageous to store the pile holder in the open position on the vessel, depending on deck space and arrangement of equipment on the deck.

In an embodiment, when the first jaw and the second jaw are in the closed position, the outer ends of the jaws join up, and wherein preferably a locking mechanism is provided to lock the first and second jaw in their closed positions, e.g. by connecting the other ends to each other. This may allow the first and second jaw of the pile holder to be securely closed when the pile holder is in the closed position providing a more secure gripping of the pile by the pile holder.

In an embodiment each pile engaging device comprises a suspension arm, each suspension arm having an engaging end and a pivot end, wherein the suspension arm is at the pivot end pivotable supported, such that the suspension arm is pivotable about a pivot axis, preferably the pivot end being a top end of the suspension arm and the pivot axis preferably being a horizontal pivot axis, and wherein each suspension arm is at the engaging end provided with one or more pile engaging elements.

This may allow for the pile holder to hold piles that have a direction smaller than a diameter of the pile holder. The pile engaging devices may engage the pile by the engaging end of the suspension arms. The suspension arms may move in a direction towards the pile, when the pile holder is located around the pile, by pivoting around the pivot axis.

Preferably each pile engaging device comprises a suspension arm actuator to position the suspension arm at different angular positions about the pivot axis to allow simultaneous engagement of all pile engaging devices. This may allow for more advantageous engaging of the pile by the pile engaging device.

In an embodiment the pile holding system further comprises a hydraulic power source, preferably for actuating a drive for moving the cart and/or a drive for moving the pile holder relative to the vertical support frame, which hydraulic power source is mounted on the cart.

It may be advantageous to move the pile holding system by a hydraulic power source, for example when no crane or other way of moving the pile holding system are present on the vessel. A hydraulic power system may also be easier to operate than another system.

The fourth aspect of the invention relates to a method for installation of a pile, adapted to support an offshore wind turbine, at a pile installation location, wherein use is made of a vessel according to the invention, and wherein the method comprises the following steps: a. transporting a pile to the offshore pile installation location;

b. positioning the vessel adjacent the pile installation location;

c. moving the cart from the storage position to the support position, and thus moving the pile holder from the storage position to the boarding position;

d. lowering the vertical support frame from the raised positon into the lowered position, and thus moving the pile holder from the boarding position into the holding position; e. securing the vertical support frame in its lowered positon to the mount of the cart; f. lifting the pile at an upper end thereof, and positioning the pile in the pile holder;

g. lowering the pile to the sea floor; and

h. driving the pile into the sea floor. In an embodiment of the method the step d is carried out by a crane on the vessel.

In an embodiment of the method further comprises:

i. lifting the vertical support frame from the lowered position into the raised position, and thus moving the pile holder from the holding position into the boarding position, and disengaging the pile by the pile holder;

j. moving the cart from the support position to the storage position, and thus moving the pile holder from the boarding position to the storage position .

In an embodiment of the method a sound cancellation device is mounted to the pile holder, preferably is supported by the pile holder.

Advantageous embodiments of the pile holding systems according to the invention and the methods according to the invention are disclosed in the claims and in the description, in which the invention is further illustrated and elucidated on the basis of a number of exemplary embodiments, of which some are shown in the schematic drawing.

Whilst primarily presented for illustrative purposes with reference to one or more of the figures, any of the technical features addressed below may be combined with any of the independent claims of this application either alone or in any other technically possible combination with one or more other technical features.

Fig. 1 schematically depicts a vessel according to an embodiment of the invention;

Fig. 2 schematically depicts in more detail the pile holding system shown in Fig. 1 ;

Fig. 3 schematically depicts the pile holding system of Fig. 2 in an open configuration;

Fig. 4 schematically depicts the pile holding system of Fig. 2 in an closed configuration;

Fig. 5 schematically depicts in more detail a pile engaging device of the pile holding system of Fig. 2;

Fig. 6 schematically depicts a top view of a part of the vessel of Fig. 1 ;

Fig. 7 schematically depicts a pile holding system according to another embodiment of the invention;

Fig. 8 schematically depicts a pile holding system according to the invention in a first position;

Fig. 9 schematically shows the pile holding system of Fig. 8 in a second positon;

Fig. 10 shows a side view of an embodiment of a pile holding system mounted on a deck of a vessel according to the invention; Fig. 11 shows a side view of the pile holding system according to the third aspect of the invention, in the storage position;

Fig. 12 shows a side view of the pile holding system according to the third aspect of the invention, in the holding position;

Fig. 13 shows a side view of the pile holding system according to the third aspect of the invention, in the holding position where the pile holder is moved in a first correction direction;

Fig. 14 shows a side view of the pile holding system according to the third aspect of the invention, in the storage position with a sound cancellation device attached to the pile holder;

Fig. 15 shows a perspective view of the pile holding system according to the third aspect of the invention, in the storage position;

Fig. 16 shows a perspective view of the pile holding system according to the third aspect of the invention, in the boarding position where the pile holder is in an open position; Fig. 17 shows a perspective view of the pile holding system according to the third aspect of the invention, in the holding position where the pile holder comprises a first jaw and a second jaw;

Fig. 18 shows a perspective view of the pile holding system according to the third aspect of the invention, in a first holding position;

Fig. 19 shows a perspective view of the pile holding system according to the third aspect of the invention, in a second holding position; and

Fig. 20 depicts another embodiment of a pile holder according to the invention.

It is submitted that the embodiments of pile holding systems shown, each comprise a pile holder according to the second aspect of the invention. It is submitted that the pile holding systems can also be used with alternative pile holder, for example pile holders comprising fixed pile engagement devices. Furthermore, figures 1-7 show a pile holding system according to a first aspect of the invention, i.e. configured to support the pile holder in an inboard position with the yaws in the open position. Figures 8 and 9 show a pile holding system according to the third aspect of the invention, i.e. configured to support a pile holder in a pickup position, in which pickup position the pile holder is located within the contour of the vessel and above an accessory storage of the vessel, preferably a deck area designated as accessory storage. It is submitted that the pile holder system shown in figures 1-6 can also be provided with a pick up position according to the second aspect, albeit with the yaws of the pile holder in the open position. Figures 10-19 show a pile holding system according to the fourth aspect of the invention, i.e. comprising a vertical support frame configured to be moved in a vertical direction relative to a mount between a lowered position and a raised positon, to thus enable movement of a pile holder between a holding position and a boarding position it is submitted that the pile holding system according to the fourth aspect can be configured to support a pile holder with its yaws in the closed positon within the contour of the vessel, according to the third aspect of the invention, or can be configured to support a pile holder with its yaws in the open positon within the contour of the vessel, according to the first aspect of the invention

Figs. 1-6 all relate to the same embodiment of a pile holding system 1 according to the invention. Fig. 1 depicts the pile holding system 1 on a vessel VE while handling a pile PI. Fig. 2 depicts the pile holding system 1 and the pile PI in more detail while omitting the vessel VE. Fig. 3 depicts the pile holding system 1 in an open configuration which will be described below in more detail. Fig. 4 depicts the pile holding system 1 in a closed configuration which will be described below in more detail. Fig. 5 depicts in more detail a pile engaging device of the pile holding system 1. And Fig. 6 depicts a top view of the pile holding system 1 and the portion of the vessel in the direct vicinity of the pile holding system 1.

The vessel VE includes a hull HU with at least one deck DE. The deck DE provides sufficient space to store, in this case, five piles PI in a horizontal orientation. The piles PI are preferably stored such that their longitudinal axes are parallel to a longitudinal axis of the vessel VE. The longitudinal axis of the vessel extending between a bow and an aft (i.e. stern) of the vessel.

In this embodiment, the vessel VE is a monohull vessel, but alternatively, the vessel VE could be a semi-submersible. In a non-shown embodiment, the vessel VE is a jack-up type vessel in which legs can be lowered into the water to lift the vessel at least partially out of the water so that waves have a limited or minimal effect on the vessel. The vessel can then e.g. be used in floating condition when the weather and wave conditions are good and can be used in jack-up condition when the weather and wave conditions are bad.

The pile holding system 1 is in this embodied arranged at a side of the vessel, in this embodiment the starboard side of the vessel VE to hold the pile PI outside the contour of the vessel VE at a starboard side seen from above. Alternatively, the pile holding system 1 may be arranged at a stern of the vessel to hold a pile PI outside the contour of the vessel at a stern side of the vessel seen from above.

In this embodiment, a crane CR is arranged next to the pile holding system 1. The crane CR is configured to handle a pile PI, wherein handling may include lifting a pile PI from its storage location, upending the pile PI, positioning the pile PI relative to the pile holding system 1 , and lowering the pile PI to the sea floor. However, the crane CR may also be configured to handle a pile driving mechanism PDM, which pile driving mechanism PDM is configured to actively drive the pile PI deeper into the sea bottom by applying downwardly directed forces to an upper end portion of the pile PI.

In an embodiment, when the pile PI is lowered into the water, the pile PI is initially held by the crane CR and gravity force will initially drive the pile PI into the sea bottom when the pile PI reaches the sea bottom. When lowering based on gravity stops, the crane CR can be disengaged from the pile PI and the pile driving mechanism PDM can be lifted from its storage position to be positioned on top of the pile PI to drive the pile PI deeper into the sea bottom. It is noted here that the sea bottom may alternatively be referred to as the sea floor.

The storage location of the pile driving mechanism PDM may be at the port side of the vessel as in this embodiment to serve as a counterweight during handling of a pile PI by the crane CR outside the contour of the vessel.

In case the pile holding system 1 and crane CR are arranged at the stern of the vessel, it is preferred that the crane is arranged in line with a centre of gravity of the vessel VE and the pile holding system 1 is arranged next to the crane. In such a case, it is preferred that the storage location for the pile driving mechanism is at a side of the crane CR opposite to the side where the pile holding system is arranged.

The vessel VE may also comprise deck space to store other equipment, e.g. pile extensions PX that are configured to be connected to a free upper end of a pile PI and that are configured to support a mast of an offshore wind turbine.

In Fig. 1 , the pile holding system 1 holds the pile PI in an upright position at a pile installation location next to the vessel VE, i.e. outside the contour of the vessel. In Fig. 1 , the pile has passively penetrated the sea bottom due to gravity and the crane CR is in the process of lifting the pile driving mechanism PDM in order to position the pile driving mechanism PDM on the pile PI for actively driving the pile PI further into the sea bottom. Although the pile PI is not held anymore by the crane CR, the pile holding system 1 still limits movement of the pile PI in a horizontal direction. This will be described below in more detail, but first the pile holding system 1 itself will be described in more detail.

The pile holding system 1 comprises a pile holder PH with a base structure BS, a first yaw Y1 and a second yaw Y2. In Fig. 3, an inner end IE1 and outer end OE1 of the first yaw Y1 and an inner end IE2 and outer end OE2 of the second yaw Y2 are indicated to show that the first yaw extends between the inner end IE1 and the outer end OE1 , and the second yaw extends between the inner end IE2 and the outer end OE2. Also shown in Fig. 3 is that the base structure BS extends between a first end FE and a second end SE.

As can be clearly seen in Fig. 1 , the first yaw Y1 is pivotably connected with its inner end IE1 to the first end FE of the base structure BS to pivot about a first yaw pivot axis PA1 , and the second yaw Y2 is pivotably connected with its inner end IE2 to the second end SE of the base structure BS to pivot about a second yaw pivot axis PA2. Both the first yaw Y1 and the second yaw Y2 are pivotable between a respective closed position as shown in Figs. 1 , 2, 4 and 5 and an open position as shown in Fig. 3.

In this embodiment, the base structure BS, first yaw Y1 and second yaw Y2 are similar in size, i.e. they all extend along a 120 degree arc-shaped trajectory to from a circular segment. This can be best seen in Fig. 3 in which the first and second yaw Y1 , Y2 are in the open position.

Fig. 4 clearly depicts that when the first yaw Y1 and the second yaw Y2 are in the closed position, the outer ends OE1 , OE2 of the first and second yaw Y1 , Y2 join up, even engage each other, and preferably are connected to each other, e.g. using a locking mechanism to lock the first yaw Y1 and the second yaw Y2 in their closed positions. Although locking the yaws Y1 , Y2 in their closed positions can be achieved by connecting the outer ends OE1 , OE2 to each other, it is alternatively also envisaged that the yaws are locked in their closed positions by a locking mechanism without being connected to each other.

In the closed position, the pile holder PH defines a pile passage PS for the pile PI. In Figs. 1 and 2, the pile PI is positioned in the pile passage PS, which pile may alternatively be described as being positioned in the pile holder PH. Being positioned in the pile holder thus implies that the yaws Y1 and Y2 are in the closed position to form the pile passage PS.

In the open position, the pile PI is allowed to move from and to the pile holder PI in a lateral direction, i.e. in this case the lateral direction is in a plane spanned by the base structure BS, the first yaw Y1 and the second yaw Y2. This moving option may alternatively be described as being allowed to be received in, or to be removed from, the pile holder in a lateral direction. The pile holding system 1 further comprises a plurality of pile engaging devices PED, wherein in this embodiment, the base structure BS, the first yaw Y1 and the second yaw Y2 each support two pile engaging devices PED. The pile engaging devices PED are configured to engage with an outer surface OS of a pile PI when the pile PI is positioned in the pile holder PH. To reduce friction between the pile engaging devices PED and the pile PI during lowering of the pile PI relative to the pile holder PH, the pile engaging devices PED are preferably provided with one or more pile guiding rollers GR as indicated in Fig. 5.

The base structure BS of the pile holder PH comprises a yoke YO, which yoke YO is moveably supported by a support system SS mounted on the deck DE of the vessel.

The support system SS is configured to move the pile holder PH in a first direction FD between an inboard position as depicted in Fig. 3 and an outboard position as depicted in Figs. 1 , 2, 4 and 6.

In the outboard position, the pile holder PH is located outside the contour of the vessel VE for holding the pile PI in the upright position at the installation location. In the inboard position with the first yaw Y1 and the second yaw Y2 in the open position, the pile holder PH is located within the contour of the vessel.

In this embodiment, the first direction FD is a substantially horizontal direction. The support system SS comprises a track formed by rails R1 , R2 mounted on the deck DE of the vessel. The rails R1 , R2 extend in the first direction FD and support a base carriage BC for movement along the track in the first direction FD. Thus, in the embodiment shown, the base carriage comprises a U-shaped carriage frame, the carriage frame comprising two legs, each leg extending along a track, more in particular, one leg extending along R1 and one leg extending along R2. A cross section, in the form of a beam BE1 , connects the legs at an end of the legs facing the pile holder.

The yoke YO is moveably supported by the base carriage BC for moving the pile holder PH in a second direction SD, which second direction is in this embodiment also a substantially horizontal direction perpendicular to the first direction FD. The moveability of the yoke YO allows to move the pile holder PH between a first outer position, in which the yoke YO engages with a first stopper ST 1 on the beam BE1 of the base carriage BC, and a second outer position, in which the yoke YO engages with a second stopper ST2 on the beam BE1 of the base carriage BC. In the Figs. 1 , 2 and 3, the pile holder PH is near the3 first outer position, and in the Figs. 4 and 6, the pile holder PH is positioned halfway the first and second outer position.

An advantage of the moveability in both the first and second direction FD, SD, is that the support system is able to position the pile holder in a horizontal plane relative to the vessel. This in turn allows to provide active motion compensation in said horizontal plane while the pile holder supports a pile PI in the upright position at the installation location next to the vessel to compensate for movement of the vessel relative to the pile installation location.

The pile holding system 1 further comprises an actuation system including base carriage actuation devices 10, yoke actuation devices 20, and yaw actuation devices 30.

The base carriage actuation devices 10 are arranged on the base carriage BC of the support system to cooperate with a rack 11 on the respective rails R1 , R2. Driving the base carriage actuation devices 10 will result in movement of the base carriage BC relative to the rails R1 , R2 in the first direction FD.

The yoke actuation devices 20 are arranged on the yoke YO to cooperate with a rack 12 on the beam BE1 of the base carriage BC. Driving the yoke actuation devices 10 will result in movement of the yoke YO and thus the pile holder PH relative to the base carriage in the second direction SD.

The yaw actuation devices 30 are in this case hydraulic cylinders 30 arranged between the base structure BS and the first yaw Y1 and the second yaw Y2, respectively. Driving the yaw actuation devices allows to move the corresponding first or second yaw Y1 , Y2 between its open position and its closed position.

The pile holding system 1 preferably comprises a control system to control movement of the pile holder PH based on user and/or sensor input by sending corresponding driving signals to the actuation system.

Fig. 5 depicts in more detail a pile engaging device PED as described above. In Fig. 5, the pile engaging device PED is associated with the first yaw Y1 , but the description below also applies to the other pile engaging devices PED.

The pile engaging device PED comprises a chassis CH moveably supported on a track structure TS arranged on the first yaw Y1. The track structure TS which may be embodied as a rack or rail section extends in this embodiment along a longitudinal direction of the first yaw Y1. A drive DR1 , preferably part of the actuation system and controlled by the control system, is provided, which drive DR1 is adapted to move the chassis CH along the track structure.

The pile engaging device PED further comprises a suspension arm SA having an engaging end EE and a pivot end PE, wherein the suspension arm SA is at the pivot end PE pivotable supported, such that the suspension arm SA is pivotable about a pivot axis PA3. Preferably, as in this embodiment, the pivot end PE is a top end of the suspension arm and the pivot axis PA3 preferably is a horizontal pivot axis. The suspension arm SA is at the engaging end EE provided with one or more pile engaging elements in the form of pile guiding rollers GR.

The pile engaging device PED further comprises a suspension arm actuator SAA, which may be part of the actuation system and be controlled by the control system, to position the suspension arm at different angular positions about the pivot axis PA3. This allows to move and position the pile engaging elements GR of a pile engaging device PED in a radial direction relative to the first yaw, second yaw or base structure. An advantage thereof is that when the first and second yaw are in their closed positions, all pile engaging devices can simultaneously engage with piles having different diameters. It is also possible to adjust the position of the pile engaging device in radial direction to adjust to different diameters used in a single pile, e.g. when the pile tapers inwards at the upper end thereof as shown in Fig. 2, where a main portion of the pile has a diameter DM and an upper end of the pile has a diameter DI2, and where DI1>DI2. The drive DR1 and corresponding track structures allow to move and position the pile engaging devices in a tangential direction, which has the advantage that an obstruction or protrusion on the outer surface OS of the pile can be circumvented by the pile engaging devices during lowering of the pile.

The pile engaging device PED in Fig. 5 further comprises a carrier CR supporting two guiding rollers GR, which carrier is pivotably connected to a support end, i.e. the engaging end EE in this embodiment, of the suspension arm SA to pivot about a carrier pivot axis CPA. The carrier pivot axis CPA preferably extends parallel to the suspension arm pivot axis PA3.

The pile holding system further comprises a fender structure FS, in this case mounted on the base structure BS, for rough positioning of the pile PI when the pile PI is positioned in the pile passage PS and/or for collision prevention between pile and other pile holder portions, e.g. the pile engaging devices on the base structure. In this embodiment, the yoke YO comprises an extension EX for supporting equipment, here embodied as containers CON. The containers CON may contain equipment used for operating the pile holding systems such as electric or hydraulic drives, gear boxes, winches, etc., but may also be used for storage of other equipment. The use of the extension to support equipment can be advantageously be used to provide a counterweight for the pile holder PH to reduce loads on the yoke YO and/or beam BE1. The extension EX and containers CON have been omitted in Fig. 4.

The embodiment shown in Figs. 1-6 allow to carry out a method for installation of a pile adapted to support an offshore wind turbine, wherein use is made of the vessel VE, and wherein the method includes the step of transporting a pile PI to the offshore pile installation location. As the vessel VE comprises storage locations for piles, the vessel itself may carry out this step, but the piles may also be transported using a separate vessel, e.g. when the vessel VE runs out of piles PI.

The pile installation location is outside of the contour of the vessel. The pile holder PH is moved from the inboard position to the outboard position and the first and second yaw Y1 , Y2 are positioned in the open position. This makes the pile holder ready for receiving a pile.

A pile PI is lifted at an upper end thereof and positioned in the pile holder PH. Positioning the pile PI in the pile holder may be carried out in different ways, including:

1. positioning the pile at the pile installation location and subsequently moving the pile holder towards the pile until the fender structure FS engages with the pile;

2. positioning the pile holder at the pile installation location and subsequently moving the pile towards the pile holder until the fender structure FS engages with the pile; and

3. simultaneously moving the pile holder and the pile towards each other at the pile installation location until the fender structure engages with the pile.

In an alternative embodiment, e.g. when the pile holder does not have a fender structure, positioning the pile in the pile holder may be carried out until the pile engages with the pile engaging devices arranged on the base structure. Positioning and moving the pile in the pile holder preferably involves motion in a sideways direction, i.e. a substantially horizontal direction not excluding motion in any other direction.

Once the pile is positioned in the pile holder, the first yaw Y1 and the second yaw Y2 can be moved to their closed positions to hold the pile in the pile passage. The pile can now be lowered to the sea floor while being held by the pile holder. The crane CR may be used to handle the pile. When the pile reaches the sea floor, gravity forces will initially drive the pile into the sea floor. When this process stops, the crane can be

disengaged from the pile and the pile driving mechanism PDM can be used to actively drive the pile into the sea floor preferably while being held by the pile holder.

Figure 7 depicts a pile holding system 1 according to another embodiment of the invention. The pile holder PH is similar to the pile holder of the embodiment of Figs. 1-6 and will not be described in detail here to prevent unduly repetition of features and embodiments.

The main difference between the two embodiments is the support system SS and the connection thereof to the base structure BS of the pile holder PH.

Also in this embodiment of Fig. 7, the support system is configured to be mounted on the deck DE of a vessel VE. The support system SS is configured to move the pile holder PH in a first direction between an inboard position and an outboard position.

In this embodiment, the first direction FD is a substantially horizontal direction. The support system SS comprises a track TR mounted on the deck DE of the vessel. The track TR extend in the first direction FD and support a base carriage BC for movement along the track in the first direction FD.

Where in Figs. 1-6, the base carriage has a substantially U-shaped form seen in plan view and the yoke YO of the base structure is moveable along the beam BE1 forming the connection between the legs of the U-shape, the base carriage BC of Fig. 7 has a

substantially T-shaped form seen in plan view. The part of the base carriage corresponding to the vertical bar of the T-shape engages with the track TR for moving in the first direction while the part of the base carriage BC corresponding to the horizontal bar of the T-shape forms another track TR2 extending in the second direction to engage with the base structure BS of the pile holder PH for moving in the second direction.

An advantage of this embodiment is that the required deck space for the support system is relatively small due to the slender design of the track TR and corresponding base carriage BC. Another advantage may be that the containers CON with equipment can be easier arranged on the base carriage itself. It will be apparent for the skilled person that sufficient measures have to be taken to moveably connect the base structure BS to the other track TR2 and to moveably connect the base carriage to the track TR. To this end, guiding elements, such as guiding wheels GW may be provided.

It is submitted that figure 3 and figure 7 depict an embodiment of a pile holder according to the second aspect of the invention, which pile holder in the embodiment shown is supported on a pile holder support system to be mounted on a vessel, e.g. for installation of a pile adapted to support an offshore wind turbine according to the first aspect of the invention.

The Pile holder PH, for use in a pile holding system to be mounted on a deck of a vessel, e.g. for installation of a pile adapted to support an offshore wind turbine, comprises a base structure BS, a first yaw Y1 , a second yaw Y2, track structures TS, and pile engaging devices PED. In the particular embodiment shown, the pile holder isprovided with three primary pile engaging dveices and three secondary pile engaging devices.

The first jaw Y1 and the second jaw Y2 each extend between an inner end I E1 and an outer end OE1 , The inner end IE1 and outer end OE1 of the first yaw Y1 and an inner end IE2 and outer end OE2 of the second yaw Y2 are indicated to show that the first yaw extends between the inner end IE1 and the outer end OE1 , and the second yaw extends between the inner end IE2 and the outer end OE2. The base structure BS extends between a first end FE and a second end SE.

The first yaw Y1 and the second yaw Y2 are pivotable connected at the inner end thereof to a respective pivot part of the base structure BS. The first yaw Y1 is pivotably connected with its inner end IE1 to the first end FE of the base structure BS to pivot about a first yaw pivot axis PA1 , and the second yaw Y2 is pivotably connected with its inner end IE2 to the second end SE of the base structure BS to pivot about a second yaw pivot axis PA2. Both the first yaw Y1 and the second yaw Y2 are pivotable between a respective closed position as shown in Figs. 1 , 2, 4 and 5 and an open position as shown in Fig. 3.

In the closed position the pile holder defines a pile passage for the pile held in the pile holder. In the open position, the yaws allow the pile to be received in, or to be removed from, the pile holder in a lateral direction.

The pile engaging devices PED comprise a chassis CH moveably supported on a track structure TS arranged on the pile holder PH. The track structures are comprised in the first yaw and the second yaw, and in the embodiment shown, in the base structure. The track structures extend along a longitudinal direction of the respective first yaw, second yaw and base structure,

The track structures TS may be embodied as a rack or rail section. The track structures in the embodiment shown extends along a longitudinal direction of the first yaw Y1 the second yaw Y2 and the base structure BS. A drive DR1 , preferably part of the actuation system and controlled by the control system, is provided, which drive DR1 is adapted to move the chassis CH of the pile engaging devices, more in particular the pile engaging elements, along the respective track structures, and thus along an inner circumference of the pile holder while engaging a pile, to rotate a pile supported by a crane in the pile holder about its longitudinal axis.

In the embodiment shown, both the primary and the secondary pile engaging devices comprise a chassis, which chassis is moveably supported on one of the track structures.

Each chassis is provided with a drive adapted to move the chassis along the track structure, and therefore move the pile engaging devices, more in particular the pile engaging elements, along an inner circumference of the pile holder while engaging a pile, to rotate a pile supported by a crane in the pile holder about its longitudinal axis.

The pile engaging devices furthermore each comprise a chassis, one or more pile engaging elements, e.g. each comprise one or more pile guiding rollers for engaging the pile in the pile passage, and an actuator to move the one or more pile engaging elements between an active position and a passive position for respectively engaging and releasing the pile located in the pile holder, and to allow simultaneous engagement of all primary pile engaging devices with piles having different diameters, when the pile engaging elements are in the active position and the first and second yaw are in their closed positions,

The secondary pile engaging devices are interposed between the primary pile engaging devices, such that along the circumference of the pile holder, the primary engaging devices alternate with the secondary engaging devices. Thus the pile holder comprises two groups of three pile engaging devices.

The pile holding system further comprises a control system configured to control the drives of the pile engaging devices, and to drive the pile engaging devices in unison along the track structures. In the particular embodiment shown, the control system of the pile holding system is configured to control the drives of the primary pile engaging devices, and to drive the primary pile engaging device in unison along the track structures, and to control the drives of the secondary pile engaging devices, and to drive the secondary pile engaging devices in unison along the track structures,

Thus, in the embodiment shown, a pile supported in the pile holder can be rotated by both the primary pile engaging devices and the secondary pile engaging devices. This is for example beneficial when a surface feature of the pile is aligned with one of the primary pile engaging devices, preventing that pile engaging device from engaging the pile. In such a situation, the secondary pile engaging devices can be used, instead of the primary pile engaging devices, to engage and rotate the pile over a first angle. Once the pile has been rotated by the secondary pile engaging devices, the surface feature may have been moved sufficiently for the primary pile engaging devices to engage the pile and rotate the pile over a second angle.

Figure 8 depicts a pile holding system 101 according to the invention mounted on a deck of a vessel VE. In the embodiment shown. The pile holdings system is depicted in figure 8 in a first positon and in figure 9 in a second position

The pile holding system 101 comprises a pile holder PH with a base structure BS, a first yaw Y1 and a second yaw Y2. As can be clearly seen in Fig. 1 , the first yaw Y1 is pivotably connected with its inner end IE1 to the first end FE of the base structure BS to pivot about a first yaw pivot axis PA1 , and the second yaw Y2 is pivotably connected with its inner end IE2 to the second end SE of the base structure BS to pivot about a second yaw pivot axis PA2. Both the first yaw Y1 and the second yaw Y2 are pivotable between a respective closed position as shown in Figs. 8 and 9 and an open position this configuration is similar to the configuration of the exemplary embodiment for example depicted in figure 4.

In this embodiment as well, the base structure BS, first yaw Y1 and second yaw Y2 are similar in size, i.e. they all extend along a 120 degree arc-shaped trajectory to from a circular segment.

In the particular embodiment shown, the pile holding system 1 is configured to move the pile holder PH between an outboard position, depicted in figure 8, and an inboard position, depicted in figure 9. Furthermore, in the embodiment shown, the inboard position is also a pickup positon PL. In the pickup position the pile holder PH is located within the contour of the vessel VE and above an accessory storage AS of the vessel, to enable an accessory that is stored in the accessory storage to be attached to the pile holder,

In the embodiment shown, the accessory storage AS is located on the deck of the vessel VE, and holds a vertical collapsible noise mitigation screen NMS, in its collapsed position. In figure 8 the accessory is depicted both demounted and in the accessory storage, and mounted to the pile holder. In figure 9, the pile holder PE is depicted in the pickup position, in which it is located above the noise mitigation screen NMS.

The support system SS comprises a base track TR, which base track comprises a beam BE that is mounted on the deck DE of the vessel, similar to the embodiment depicted in figure 7. The track, or base track, TR extends in the first direction FD and supports a base track carriage, referred to as base carriage BC, for movement along the track in the first direction FD, the first direction FD being a substantially horizontal direction.

In the embodiment shown in figure 8 and figure 9, the base track TR comprises a single beam structure BE mounted on the deck of the vessel, and the pickup location PL is located at a side of the base track.

Furthermore, in the embodiment shown, the base structure BS ha an a-symmetrical configuration, when seen in the top view depicted in the figures. The Base structure extends on one side to enable the pile holder to be moved into and supported above the pickup position. In an alternative embodiment, the base structure may extend on both sides, and thus be configured to move the pile holder, and support the pile holder, on opposite sides of the beam BE in a pickup position.

In an alternative embodiment, for example similar to the embodiment depicted in figure 6, the pile holder support system PSS comprises a first base track R1 and a second base track R2, the first base track and the second base track extending in the first direction, each base track preferably comprising a single beam structure to be mounted on the deck of the vessel. In a preferred embodiment, the pile holder support system is configured such that the pile holder can be positioned above a pickup positon located between the first base track and the second base track. In such an embodiment, the base tracks are preferably spaced apart over a distance similar to, or large than, the diameter of the pile holder. Thus, the accessory storage can hold an accessory having dimensions, in particular a diameter, similar to the diameter of the pile holder.

Figure 10 depicts another embodiment of a pile holder according to the second aspect of the invention, which pile holder in the embodiment shown is part of a pile holding system according to the fourth aspect of the invention. Fig. 10 shows a side view of an embodiment of a pile holding system 201 mounted on a deck 202 of a vessel 203 according to the invention. The vessel 203 comprises a hull 204 that supports the deck 202. The pile holding system 201 is configured to support a pile adapted to support an offshore wind turbine in an upright position at a pile installation location next to the vessel 203.

The pile holding system 201 comprises a pile holder 205 which has a plurality of pile engaging devices 206 for engaging the pile. The pile holding system 201 further comprises a support device 207 to be mounted on the deck 202 of the vessel 203. The support device 207 moveably supports the pile holder 205, and is configured to support the pile holder 205 in an outboard holding position, in which the pile holder 205 is outside the contour of the vessel 203, and in an inboard storage position, in which the pile holder 205 is substantially within the contour of the vessel 203.

The support device 207 comprises a track 208 which extends linearly between a support end 209 thereof and a storage end 210 thereof. The support device 207 further comprises a cart 211 , which is mounted on the track 208. The cart 211 can move along the track 208 between the support end 209 and the storage end 210. The cart 211 is provided on a front end thereof with a mount 212. The cart 211 may be moved by a cart drive such as a rack and pinion drive, which is configured to move the cart 211 along the track 208.

The support device 207 further comprises a vertical support frame 213. The vertical support frame 213 extends between a lower end 214 thereof and an upper end 215 thereof. The vertical support frame 213 is configured to be moved in a vertical direction relative to the mount 212 between a lowered position and a raised position. The vertical support frame 213 may be secured to the mount 212 in the lowered position and in the raised position. The vertical support frame 213 in the proximity of the lower end 214 thereof supports the pile holder 205.

The support device 207, when mounted on the deck 202 of the vessel 203, enables by movement of the cart 211 with the vertical support frame 213 in the raised position, the pile holder 205 to be moved substantially parallel to the track 208 over a distance similar to at least an inside diameter of the pile holder 205, preferably similar to at least an outside diameter of the pile holder 205, between the storage positon depicted in fig. 11 , in which storage position a vertical projection of the pile holder 205 is located substantially within the contour of the vessel 203, and a boarding position, in which boarding position a vertical projection of the pile holder 205 is located substantially outside the contour of the vessel 203. The support device 207, when mounted on the deck 202 of the vessel 203, may further enable by movement of the vertical support frame 213 between the raised and the lowered position, the pile holder 205 to be moved substantially perpendicular to the track 202 over a distance similar to at least a height of the pile holder 205, preferably at least three times the height of the pile holder 205, between the boarding position, in which boarding position a horizontal projection of the pile holder 205 is located above the deck 202 of the vessel 203, and a lowered holding position depicted in figure 12, in which holding position a horizontal projection of the pile holder 205 is located below the deck 202 of the vessel 203.

The pile holding system 201 of figure 10 is further provided with a holder mount 216 which moveably supports the pile holder 205, such that the pile holder 205 can be moved relative to the vertical support frame 213 in a second correction direction, which second correction direction is in a substantially horizontal plane and is substantially perpendicular to the linear direction of the track 208. The pile holder mount 216 may comprise a rack and pinion drive for moving the vertical support frame 213 in the second correction direction.

The vertical support frame 213 is further provided with a first coupling device 217 in the proximity of the lower end 214 of the vertical support frame 213, which first coupling device 217 is configured for securing the vertical support frame 213 in the raised position to the mount of the cart. The vertical support frame 213 is also provided with a second coupling device 218 in the proximity of the upper end 215 of the vertical support frame 213, which second coupling device 218 is configured for securing the vertical support frame 213 in the lowered position to the mount 212 of the cart 211.

In the particular embodiment shown, the vertical support frame 213 is also provided with a third coupling device 219, located between the first coupling device 217 and the second coupling device 218. The third coupling device 219 is configured for securing the vertical support frame 213 in the raised position to the mount 212 of the cart 211 with the pile holder 25 closely adjacent the track 208 and/or deck 202, see for example figure 11.

The pile holding system 201 of figure 10 may be provided with a sound cancellation device 220 such as the one in figure 25 for cancelling sound produced by driving a pile in a sea bed.

Fig. 11 shows a side view of the pile holding system 201 in the storage position. The pile holding system 201 of figure 11 may be the pile holding system 201 of figure 10 but it may also be a different pile holding system. Fig. 11 shows the pile holding system 201 in the storage position in which the cart 211 is located near the storage end 210 of the track 208 and the pile holder 201 is located substantially within the contour of the vessel 203.

The vertical support frame 213 is mounted to the cart 211 by the third coupling device 219 such that the pile holder 205 is closely adjacent to the track 208 and the deck 202. The pile holder 205 is located substantially vertical above the track 208. The vertical support frame 213 is located partially to the side of the track 208.

Fig. 12 and figure 13 show a side view of the pile holding system 201 in the holding position. The cart 211 is located near the support end 209 of the track 208 and the pile holder is located outside of the contour of the vessel 203 and below the deck 202 of the vessel 203. In both figure 12 and 13 the vertical support frame is secured by the second coupling device 218 which is located in the proximity of the upper end 215 of the vertical support frame 213.

Figure 13 shows the pile holding system 201 wherein the pile holder 205 is moved in a first correction direction for correcting the position of the vessel 203 relative to the position of a pile.

Fig. 14 shows a side view of the pile holding system 201 in the storage position with a sound cancellation device 220 attached to the pile holder 205. The pile holder 205 and vertical support frame 213 are connected to a crane 221 for movement between the first and third coupling devices (217,219). The vertical support frame 213 is mounted to the mount 212 of the cart 211 by the first coupling device 217.

Fig. 15 shows a perspective view of the pile holding system 201 in the storage position. The cart 211 is provided on a single track beam 208 on the deck 202 of the vessel 203. The cart 211 is located near the storage end 210 of the track 208. The pile holder 205 is located above the track 208 of the pile holding system 201.

Fig. 16 shows a perspective view of the pile holding system 201 in the boarding position. The cart 211 is provided on a single track beam 208 on the deck 202 of the vessel 203. In this embodiment the pile holder 205 comprises a base structure 222, a first jaw 223 and a second jaw 224. The first jaw 223 and the second jaw 224 each extend between an inner end and an outer end, and wherein the first 223 and second jaw 224 are pivotable connected at the inner end thereof to a respective pivot part of the base 222 to pivot about a yaw pivot axis between a closed position. The pile holder 205 defines a pile passage for the pile held in the pile holder 205, and an open position, to allow the pile to be received in, or to be removed from, the pile holder 205 in a lateral direction. The base structure 222, the first jaw 223, and the second jaw 224 each support at least one of the plurality of pile engaging devices 206. A locking mechanism 225 is provided to lock the first jaw 223 and the second jaw 224 in a closed position.

The pile holder 205 is in the open position in figure 16. In this position the pile holder 205 may receive a pile or a pile may be removed from the pile holder 205.

Fig. 17 shows a perspective view of the pile holder 201 in the holding position. The cart 211 is provided on a single track beam 208 on the deck 202 of the vessel 203. The first jaw 223 and second jaw 224 are in the closed position and the locking mechanism 225 is engaged to prevent the first jaw 223 and second jaw 224 from moving apart, opening the pile holder 205.

Fig. 18 and fig. 19 show the pile holder in perspective view in a first holding position and a second holding position. Relative to figure 18, in figure 19 the pile holder 205 is moved along the second correction direction. The holder mount 216 allows movement of the pile holder 205 along the second correction direction.

Other variations to the disclosed embodiments can be understood and effected by those skilled in the art in practicing the claimed invention, from study of the drawings, the disclosure, and the appended claims. In the claims, the word“comprising” does not excluded other elements or steps, and the indefinite article“a” or“an” does not exclude a plurality. A single processor or other unit may fulfil the functions of several items recited in the claims.

The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measured cannot be used to advantage. Any reference signs in the claims should not be construed as limiting the scope.

The invention is by no means limited to the exemplary embodiment described herein above, but comprises various modifications hereto, in so far as they fall within the scope of the following claims.

Figure 20 depicts another embodiment of a pile holder according to the second aspect of the invention, which pile holder in the embodiment shown is supported on a wave-induced motion compensated pile holder support system to be mounted on a vessel, e.g. for installation of a pile adapted to support an offshore wind turbine.

The system comprises: - a base frame 110 to be mounted on the vessel;

- a support frame 120 arranged above the base frame at a distance thereof;

a support system for moveably supporting the support frame from the base frame having an active motion compensated actuation system for moving the support frame relative to the base frame, e.g. as described herein already.

The pile holder 250 comprises a base structure 251 mounted to the support frame 20. In this embodiment, the base structure 251 is pivotally mounted to the support frame 20 to pivot relative to the support frame 20 about base pivot axis 252 between a substantially vertical orientation and a substantially horizontal orientation. In this example it is envisaged that this tilting is only in view of sailing with the vessel, mooring in a port, etc., as it is envisaged that a pile is hoisted by a crane and placed in vertical orientation before engagement thereof by the pile holder 250.

The pile holder 250 has an annular structure of which a section is formed by the base structure 251 , and of which the remainder is formed by two semi-circular jaws 260, 261. These jaws 260, 261 are each pivotally connected at an inner end thereof to a respective pivot part of the base structure 251 and pivotal about a pivot axis 262, 263 between a closed position, wherein outer ends of the jaws 260, 261 join up, and an opened position. The actuation of each jaw 260, 261 is done by a jaw actuator, e.g. a hydraulic cylinder 265.

A locking mechanism 277 is preferably provided to lock the outer ends of the semi-circular jaws 260, 261 to one another.

The annular structure of the pile holder 250, as preferred, is provided with a circular support track structure 270 that carries multiple pile engaging devices 280, e.g. three primary pile engaging devices and three secondary pile engaging devices, here with pile guiding rollers 285, e.g. four or more, here six, of such devices.

The pile engaging devices 280 are movable along the circular support track structure, at least one or more of them, at least over an arc segment of the circle, so as to allow for adaptation of the angular position of the pile engaging devices 280 relative to the passage for the pile.

Each pile engaging device 280, as preferred, carries one or more pile engaging elements, here a pair of two pile guiding rollers 285 in a movable manner allow for adjustment of the radial position of the rollers 285 relative to the passage for the pile. Here each pile engaging device comprises a suspension arm 290 that pivotal about a horizontal axis 291 , here as preferred from a top end of the arm 290, relative to a chassis 295 of the device that is supported on the track structure 270.

A suspension arm actuator, here a hydraulic cylinder 297, is provided between the chassis 295 and the arm 290 to adjust the radial position of the roller(s) 285.

Each chassis 295 here is provided with a motorized drive adapted to move the chassis 295 along, possibly a section of, the circular track structure so as to adjust the angular position of the device 280.

A fender structure 300 is mounted here, as preferred, on the base structure, e.g. in view of a rough positioning of the pile relative to the pile holder.