WO2024263027A1

WO2024263027A1 - Pile holding system

Info

Publication number: WO2024263027A1
Application number: PCT/NL2024/050311
Authority: WO
Inventors: Jurgen Arjan ZIJLMANS; Adriaan Lammert SMIT; Erwin Vincent Van Liere
Original assignee: IQIP Holding BV
Current assignee: IHC IQIP Holding BV
Priority date: 2023-06-19
Filing date: 2024-06-11
Publication date: 2024-12-26
Anticipated expiration: 2025-12-19
Also published as: TW202517872A; NL2035122B1

Abstract

A pile holding system for installing an offshore foundation pile into ground is disclosed comprises a mounting assembly for mounting the pile holding system to a marine vessel, the mounting assembly having a plane that is substantially parallel to the deck of the vessel, in use; and a pile holder assembly having a gripping plane and a working axis which is normal to the gripping plane. The working axis is substantially aligned with a central axis of a pile during a pile driving operation. The pile holder assembly is coupled to the mounting assembly via at least one pivot point, the pile holder assembly being pivotable at the at least one pivot point about a pivot axis relative to the mounting assembly between a deployed position and a stowed position. The pivot axis is angled with respect to the plane of the mounting assembly and angled with respect to the gripping plane of the pile holder assembly.

Description

PILE HOLDING SYSTEM

The present invention relates to a pile holding system for installing an offshore foundation pile into ground. More specifically, although not exclusively, this invention relates to a pile holding system for installing offshore monopiles, a vessel containing such a system and to a method for installing an offshore foundation pile into ground.

Offshore foundation piles, such as monopiles, are generally installed by suspending the pile from the side of a marine vessel, in a vertical configuration, to be driven into ground below the water. Initially the pile is typically lowered through the water and to the ground using a crane and is generally held against a side of the vessel by a pile holding system. The pile holding system maintains the pile in a vertical orientation during driving of the pile into the ground. In some cases, the pile holding system supports the pile during deployment, and is therefore rotated with the pile as the pile is upended by the crane via a pile upending tool or the like. The pile holding system typically has a pile gripper assembly with jaws, which surround the pile. The pile holding system typically has a mounting assembly for mounting the pile holding system to the vessel.

With known systems the pile follows a linear path as it is upended. That is, the tip of the pile stays in the same vertical plane that is parallel with an inboard/outboard direction. This requires high skill from the cranes operator as the linear path contrasts with the required rotation of the crane during the upending motion and often leads to erratic or jerky movements of the pile. In addition, the pile and therefore also the pile holding system must be positioned a minimum distance from the base of the crane due to the minimum radius of some crane systems. This is a particular problem for cranes with a large housing and/or boom.

Undoubtedly, due to the large size of offshore foundation piles, the pile holding system is large and occupies a significant amount of space on the vessel. It is preferable to optimize space and movement of the piles as well as other equipment required for pile installation, enabling safe and quick operation.

It would therefore be advantageous to overcome at least some of the above limitations.

According to a first aspect of the invention there is provided a pile holding system for installing an offshore foundation pile into ground, the pile holding system comprising: a mounting assembly for mounting the pile holding system to a marine vessel, the mounting assembly having a plane that is substantially parallel to the deck of the marine vessel, in use; and a pile holder assembly having a gripping plane and a working axis which is normal to the gripping plane, wherein the working axis is substantially aligned with a central axis of a pile during a pile driving operation, wherein the pile holder assembly is coupled to the mounting assembly via at least one pivot point, the pile holder assembly being pivotable at the at least one pivot point about a pivot axis relative to the mounting assembly between a deployed position in which the working axis of the pile holder assembly is substantially vertical and a stowed position in which the working axis is substantially horizontal or substantially parallel with the plane of the mounting assembly, wherein the pivot axis is angled with respect to the plane of the mounting assembly and angled with respect to the gripping plane of the pile holder assembly.

Angling the pivot axis with respect to both the plane of the mounting assembly and the gripping plane of the pile holder assembly fundamentally changes the path followed by the pile holder assembly, and consequently the offshore foundation pile, as it moves between deployed and stowed positions, compared with conventional systems. That is, the tip of the pile moves through an elliptical path as it moves from its position on the deck of the vessel to its vertical position suspended from the side of the vessel. The elliptical path is more naturally aligned with the rotation of the crane performing the upending of the pile and avoids issues with the cranes minimum radius. The movement is also easier for an operator to perform and therefore allows the operator to move the pile more smoothly without jerky movements. As such the risk of damage to the pile during deployment is reduced. The change in the path followed by the pile holder assembly also allows the pile holder assembly to be positioned closer to the crane thus optimising deck space. The resulting system is therefore more compact.

In certain embodiments, the pile holding system comprises a connection assembly comprising at least one connection member; wherein the at least one connection member comprises a first end and a second end, wherein the first end of the at least one connection member is connected to, or integral with, the mounting assembly and the second end of the at least one connection member is connected to the pile holder assembly, and wherein the second end of the at least one connection member includes the at least one pivot point.

In certain embodiments, the pile holding system comprises a connection assembly comprising a first connection member and a second connection member; wherein the first and second connection members each comprise a first end and a second end, wherein the first end of the first and second connection members are connected to, or integral with, the mounting assembly and the second end of the first and second connection members are connected to the pile holder assembly, and wherein the second end of the first connection member includes the first pivot point and the second end of the second connection member includes the second pivot point.

In certain embodiments, the pile holder assembly is coupled to the mounting assembly via a first pivot point and a second pivot point, the pile holder assembly being pivotable at the first pivot point and the second pivot point about the pivot axis relative to the mounting assembly. Coupling the pile holder assembly to the mounting assembly via two pivot points allows the load (of the pile holder assembly and the pile) to be better distributed through the system.

In certain embodiments, the first pivot point and the second pivot point are laterally spaced, wherein the lateral spacing between the first pivot point and the second pivot point is equal to or less than the outer diameter of an annular pile holder of the pile holder assembly. Providing a lateral spacing that is equal to or less than the outer diameter of the annular pile holder ensures the system remains compact.

In certain embodiments, the first pivot point and the second pivot point are offset in a direction that is normal to the gripping plane of the pile holder assembly when the pile holder assembly is in the deployed position.

In certain embodiments, the first pivot point and the second pivot point are offset in a direction that is normal to the gripping plane of the pile holder assembly when the pile holder assembly is in the stowed position.

In certain embodiments, the pile holder assembly comprises an annular pile holder member. This allows normal operations of the system during installation of the offshore pile into the ground, while the force capacity of the system is better controlled when the system is used on a floating vessel.

In certain embodiments, the annular pile holder member comprises at least two jaw elements connectable to each other by locking means. Advantageously, this provides the possibility to open the pile holder to allow the pile to be more easily inserted into the jaws while in an open configuration.

In certain embodiments, the pile holder assembly further comprises a pile holder support member, configured to support the annular pile holder member while holding the pile. This provides a robust support for the pile.

In certain embodiments, the pile holder support member comprises a pile engaging device for engaging with the outer surface of the pile.

In certain embodiments, the pile engaging device comprises a resilient element. This provides dampening of the forces transferred between the pile engaging device 170 and the pile. This reduces the chance of damage to the pile during movement and ensures the motion is as smooth as possible.

In certain embodiments, the annular pile holder member comprises two or more rotatable engagement members for engaging with the outer surface of the pile. The rotatable engagement members allow adjustment in the axial position and/or rotational orientation of the pile in use.

In certain embodiments, the annular pile holder member and the pile holder support member are spaced from each other along the working axis of the pile holder assembly, wherein the annular pile holder member and the pile holder support member are connected by means of an actuation system such that the annular pile holder member is movable relative to the pile holder support member in a direction normal to the working axis of the pile holder assembly. This allows easy correction of the position of the annular pile holder member relative to either the pile or the floating vessel or both.

In general, by suspending the annular pile holder from the pile holder support member, the pile holder support member is used as an additional holding member for the pile, in particular during upending of the pile. As such, the pile is better supported at its base during upending and rotation of the pile is better controlled.

In certain embodiments, the pile holding system comprises actuating means, wherein actuation of the actuation means causes the pile holder assembly to pivot about the pivot axis relative to the mounting assembly.

In certain embodiments, the actuation means comprises at least one actuator, wherein the at least one actuator is coupled to the pile holder assembly at a position spaced from the pivot axis such that, upon actuation of the at least one actuator, the at least one actuator applies a force to the pile holder assembly that generates a torque about the pivot axis. The use of actuators as the actuation means is simple and effective.

In certain embodiments, the at least one actuator is coupled to the pile holder assembly via an actuator pivot point, the at least one actuator being pivotable at the actuator pivot point about an actuator pivot axis relative to the pile holder assembly, wherein the actuator pivot axis is parallel to the pivot axis. Providing an actuator pivot axis parallel to the pivot axis ensures the required torque is most efficiently applied around the pivot axis.

In certain embodiments, the actuation means comprises a first actuator and a second actuator, wherein the first actuator is coupled to the pile holder assembly via a first actuator pivot point and the second actuator is coupled to the pile holder assembly via a second actuator pivot point, the first actuator being pivotable at the first actuator pivot point about the actuator pivot axis relative to the pile holder assembly, and the second actuator being pivotable at the second actuator pivot point about the actuator pivot axis relative to the pile holder assembly.

In certain embodiments, the pile holding system further comprises a translation system, wherein the mounting assembly is mounted on the translation system, the mounting assembly being movable along the translation system between a retracted inboard position and an extended outboard position. This enables full retraction of the system, inboard the vessel’s deck when not in use, such that the sailing operation, among other operations, can be performed in a secured manner.

In certain embodiments, the pile holding system further comprises a noise mitigation system connected to the lower part of the pile holding assembly. Advantageously, this enables to have a system that is ready to operate on the installation of the pile into the ground, since the noise mitigation system (NMS) is provided within the claimed system, such the it only needs to be lowered (the NMS is a foldable system) to the ground to start the operation.

According to another aspect of the present invention there is provided a marine vessel comprising a pile holding system according to any aspect or embodiment of the invention, the mounting assembly of the pile holding system being mounted to the marine vessel.

In certain embodiments the marine vessel comprises a crane, wherein the pile holder system is positioned on the vessel adjacent to the crane. In certain embodiments, the crane is positioned opposite to the angle between the pivot axis and the plane of the mounting assembly. The angled pivot axis of the pile holder system allows the pile holder system to be positioned closer to the crane than would be the case for known systems. In certain embodiments the marine vessel comprises an upending device for upending a pile.

According to another aspect of the present invention there is provided a method for installing an offshore foundation pile into ground, wherein the method comprises: providing the pile holding system of any aspect or embodiment of the invention on a marine vessel; holding a lower end of a pile with the pile holder assembly of the pile holding system; upending the pile, wherein as the pile is upended the pile holder assembly pivots about the pivot axis relative to the mounting assembly between the stowed position and the deployed position.

Using the described pile holding system for this method ensures the movement is easier for an operator to perform and therefore allows the operatorto move the pile more smoothly without jerky movements. In addition, the pile holding system can be positioned closer to the crane while the method is performed.

In certain embodiments the pile is upended with a crane and a pile upending device.

According to another aspect of the present invention there is provided a use of the pile holding system of any aspect or embodiment of the invention for installing an offshore foundation pile into ground.

According to another aspect of the present invention there is provided a pile holding system for installing an offshore foundation pile into ground, the pile holding system comprising: a mounting assembly for mounting the pile holding system to a marine vessel, the mounting assembly having a plane that is substantially parallel to the deck of the marine vessel, in use; and a pile holder assembly having a working axis which is substantially aligned with a central axis of a pile during a pile driving operation, the pile holder assembly being coupled to the mounting assembly via a first pivot point and a second pivot point, wherein the first pivot point and the second pivot point define a pivot axis, the pile holder assembly being pivotable about the pivot axis relative to the mounting assembly between a deployed position in which the working axis of the pile holder assembly is substantially vertical and a stowed position in which the working axis is substantially horizontal or substantially parallel with the plane of the mounting assembly, wherein the first pivot point and the second pivot point are offset such that the pivot axis is angled with respect to the plane of the mounting assembly.

For the avoidance of doubt, any of the features described herein apply equally to any aspect or embodiment of the invention. For example, the method may comprise any one or more features or steps relevant to one or more features of the pile holding system.

Within the scope of this application it is expressly intended that the various aspects, embodiments, examples and alternatives set out in the preceding paragraphs, in the claims and/or in the following description and drawings, and in particular the individual features thereof, may be taken independently or in any combination. That is, all embodiments and/or features of any embodiment can be combined in any way and/or combination, unless such features are incompatible. For the avoidance of doubt, the terms “may”, “and/or”, “e.g.”, “for example” and any similar term as used herein should be interpreted as non-limiting such that any feature so- described need not be present. Indeed, any combination of optional features is expressly envisaged without departing from the scope of the invention, whether or not these are expressly claimed. The applicant reserves the right to change any originally filed claim or file any new claim accordingly, including the right to amend any originally filed claim to depend from and/or incorporate any feature of any other claim although not originally claimed in that manner.

Embodiments of the invention will now be described by way of example only with reference to the accompanying drawings in which:

Figures 1 and 2 show perspective and side views, respectively, of a pile holding system;

Figure 3 shows a top view of the pile holding system of Figure 1 with jaws open;

Figures 4 and 5 show a side view of the pile holding system of Figure 1 with the pile holder assembly in deployed and stowed positions respectively;

Figure 6 shows a side view of the pile holding system of Figure 1 in a retracted inboard position;

Figure 7 shows another side view of the pile holding system shown in Figure 5;

Figure 8 shows a top view of the pile holding system shown in Figure 4;

Figure 9 shows a perspective view of a pile holding assembly;

Figures 10 to 13 show a pile holding system holding a pile with the pile holder assembly in a stowed position;

Figures 14 to 17 show a pile holding system holding a pile during movement of the pile holder assembly from a stowed position to a deployed position; and

Figures 18 to 21 show a pile holding system holding a pile with the pile holder assembly in a deployed position. Referring first to Figures 1 to 3, there is shown a pile holding system 10 for installing an offshore foundation pile (not shown) into ground (not shown).

The pile holding system 10 includes a mounting assembly 20 for mounting the pile holding system 10 to a marine vessel 500. The mounting assembly 20 has a plane 21 that is substantially parallel to the deck 501 of the marine vessel 500, in use. The plane 21 of the mounting assembly 20 is selected depending on the orientation of the mounting assembly 20 with respect to the deck 501 of the marine vessel 500 and does not, in itself, limit the geometry or structure of the mounting assembly 20.

The pile holding system 10 includes a pile holder assembly 30. In this example the pile holder assembly 30 comprises an annular pile holder member 36. The annular pile holder member 36 defines an annulus for receiving a pile. The inner circumferential surface of the annular pile holder member 36, or an engaging element thereon, engages with the pile to hold the pile so as to prevent axial movement of the pile through the annulus.

In this example the annular pile holder member 36 comprises at least two jaw elements 33, 34. The jaw elements 33, 34 are rotatable between an open position and a closed position. In the open position the annulus of the annular pile holder member 36 is accessible through the space defined between the open jaw elements 33, 34. In the closed position the jaw elements 33, 34 are in engagement so as to create a closed annulus within the annular pile holder member 36. In this example, the jaw elements 33, 34 are each coupled to and rotatable with respect to, a central portion 35 as shown in Figure 3. The jaw elements 33, 34 are connectable to each other by locking means. As such, the pile can be locked within the annulus of the annular pile holder member 36.

The pile holder assembly 30 has a gripping plane 31 and a working axis 32, which is normal to the gripping plane 31 . The working axis 32 is substantially aligned with a central axis of a pile during a pile driving operation (as shown in Figures 10 to 21 , for example). As used herein, the ‘gripping plane’ is a plane in which the pile holder assembly 30 engages with, or grips the pile. The annulus extends across the gripping plane 31. It would be understood that there may not be a single gripping plane in which the pile holder assembly 30 engages with the pile, rather there may be a series of parallel gripping planes.

In this example the annular pile holder member 36 comprises two or more rotatable engagement members 38 for engaging with the outer surface of the pile. The rotatable engagement members 38 may be a roller or wheel, for example.

In the illustrated example there are a plurality of rotatable engagement members 38 and these rotatable engagement members 38 are arranged around the inner surface of the annular pile member 36, with three rotatable engagement members 38 positioned at each circumferential position. It would be appreciated that other configurations of rotatable engagement members 38 may be possible - for example there may be variation in the circumferential arrangement of rotatable engagement members 38 and/or the number of rotatable engagement members 38 at each circumferential position.

One or more of the rotatable engagement members 38 may have a rotational axis that is parallel to the working axis 32 of the pile holder assembly 30. In this manner, the pile may be rotated around its axis in situ when gripped by the pile holder assembly 30. One or more of the rotatable engagement members 38 may have a rotational axis that is normal to the working axis 32 of the pile holder assembly 30 - that is within the gripping plane 31 of the pile holder assembly 30. In this manner, the pile can move through the annulus during the piling operation, for example when the driving force applied to the pile overcomes the gripping force.

In the illustrated example two of the rotatable engagement members 38 at each circumferential position have a rotational axis that is normal to the working axis 32 of the pile holder assembly 30. One of the rotatable engagement members 38 at each circumferential position has a rotational axis that is parallel to the working axis 32 of the pile holder assembly 30.

In this example the rotatable engagement members 38 are radially movable with respect to the main body of the annular pile holder member 36. In this example the rotatable engagement members 38 are mounted to the main body of the annular pile holder member 36 via a plate or frame 80. A first, upper, end (as viewed in Figure 1) of the plate 80 is pivotally mounted to a flange 81 extending from the main body of the annular pile holder member 36. A second, lower, end (as viewed in Figure 1) of the plate 80 is biased or driven radially inwardly into the annulus of the annular pile holder member 36. As such, the radial position of the rotatable engagement members 38 is adjustable such that the effective size of the annulus is controllable or reactive depending on the diameter of the pile being installed. Similarly the position of the pile within the annulus is adjustable to allow the pile to remain substantially vertical during vessel movement. In this example the second end of the plate 80 is driven or biased with actuators 82, however other means of actuation are possible.

The pile holder assembly 30 is coupled to the mounting assembly 20 via at least one pivot point. In this example the pile holder assembly 30 is coupled to the mounting assembly 20 via two pivot points 41 , 42.

In other examples, the pile holder assembly 30 may be coupled to the mounting assembly 20 via any number of pivot points, for example 1 , 3 or more pivot points.

In this example the pivot points 41 , 42 are laterally spaced. That is, the pivot points 41 , 42 are spaced in a direction that extends along, or parallel to, the side of the vessel 500. In this example, the lateral spacing between the pivot points 41 , 42 is equal to or less than the outer diameter of the annular pile holder 36 of the pile holder assembly 30. This ensures the system is compact, with the lateral dimensions (i.e. the width) of the system being dictated largely by the size of the annular pile holder 36 rather than the supporting structure. The pile holder assembly 30 is pivotable at the pivot points 41 , 42 about a pivot axis 43 relative to the mounting assembly 20. The pivot axis is best shown in Figure 3. That is, at the pivot points 41 , 42 the pile holder assembly 30 is able to rotate around the pivot axis 43.

In this example the pile holding system 10 includes a connection assembly for connecting the mounting assembly 20 to the pile holder assembly 30. The connection assembly may be a separate, intermediate, structure between the mounting assembly 20 and the pile holder assembly 30. Alternatively, the connection assembly may be an integral part of the mounting assembly 20. In this example the connection assembly includes a first connection member 91 and a second connection member 92. In this example the connection members 91 , 92 are flanges that are integral with the mounting assembly 20 and protrude in the direction of the pile holder assembly 30. Specifically, a first end of each connection member 91 , 92 is integral with the mounting assembly 20 and a second end of each connection member 91 , 92 is connected to the pile holder assembly 30. The second end of the first connection member 91 includes the pivot point 42 and the second end of the second connection member 92 includes the pivot point 41. The pivot point(s) may include any suitable pivotable or rotatable connection. For example the pivot point(s) may include a roller bearing. In such examples the pile holder assembly 30 may include a shaft received within, and rotatable within, the roller bearing.

The pile holder assembly 30 is pivotable about the pivot axis 43 relative to the mounting assembly 20 between a deployed position and a stowed position. Figures 1 to 4 show the pile holder assembly 30 in the deployed position. Figures 5 and 6 show the pile holder assembly 30 in the stowed position.

In the deployed position the working axis 32 of the pile holder assembly 30 is substantially vertical. This ensures that, in operation, the offshore foundation pile is held vertically for a piling operation. In general, in the deployed position the gripping plane 31 is co-planar or parallel with the plane 21 of the mounting assembly 20 (that is, where the vessel 500 is horizontal). However, it would be understood that there may be means of motion compensation that ensures that the working axis 32 remains vertical even if the motion of the vessel causes the plane 21 of the mounting assembly 20 to deviate from horizontal. As shown in Figure 2, when positioned on the vessel 500 in the deployed position, the pile holder assembly 30 extends from the side of the vessel 500. In the stowed position the working axis 32 of the pile holder assembly 30 is substantially horizontal or substantially parallel with the plane 21 of the mounting assembly 20.

The pivot axis 43 is angled with respect to the plane 21 of the mounting assembly 20. The pivot axis 43 is also angled with respect to the gripping plane 31 of the pile holder assembly 30. That is, the pivot axis 43 is angled with respect to the gripping plane 31 of the pile holder assembly 30 in both the deployed position, the stowed position and all positions in between. As used herein the term ‘angled with respect to’ when describing an orientation of an axis with respect to a plane refers to an axis that is non-parallel with a plane. That is, the axis extends out of the plane. In this example, the pivot points 41 , 42 are offset in a direction that is normal to the gripping plane 31 of the pile holder assembly 30 when the pile holder assembly 30 is in the deployed position. Put another way, the pivot points 41 , 42 are offset in a direction that is normal to the plane 21 of the mounting assembly 20.

In this example, the pivot points 41 , 42 are offset in a direction that is normal to the gripping plane 31 of the pile holder assembly 30 when the pile holder assembly 30 is in the stowed position. Put another way, the pivot points 41 , 42 are offset within the plane 21 of the mounting assembly 20, or within a plane parallel to the plane 21 of the mounting assembly 20, the offset extending away from the mounting assembly 20. As used herein ‘extending away from the mounting assembly’ refers to extension in an outboard direction.

As will be described in more detail with regards to Figures 10 to 21 , angling the pivot axis 43 with respect to both the plane 21 of the mounting assembly 20 and the gripping plane 31 of the pile holder assembly 30 fundamentally changes the path followed by the pile holder assembly 30, and consequently the offshore foundation pile, as it moves between deployed and stowed positions, compared with conventional systems. Specifically the path followed by the pile holder assembly 30 ensures the tip of the pile 1000 moves through an elliptical path as it moves from its position on the deck of the vessel 500 to its vertical position suspended from the side of the vessel 500. This elliptical path does not stay within a single vertical plane and therefore differs from conventional systems. The elliptical path is more naturally aligned with the rotation of the crane performing the upending of the pile 1000 and avoids issues with the cranes minimum radius. The movement is also easier for an operator to perform and therefore allows the operator to move the pile more smoothly without jerky movements. As such the risk of damage to the pile during deployment is reduced.

The change in the path followed by the pile holder assembly 30 also allows the pile holder system 10 to be positioned closer to the crane thus optimising deck space. The resulting system is therefore more compact.

This is best shown in Figures 7 and 8, which show the pile holder system 10 positioned on the vessel 500 adjacent to the crane 800. The crane 800 is positioned opposite to the angle between the pivot axis 43 and the plane 21 of the mounting assembly 20. Figure 7 shows the pile holder assembly 30 in the stowed position. Figure 8 shows the pile holder assembly 30 in the deployed position. It can be seen that the rotation of the pile holder assembly 30 about the pivot axis 43 from the deployed position to the stowed position takes the pile holder assembly 30 away from the crane 800 in a lateral direction. That is, the lateral position of the pile holder assembly 30 moves from right to left in the view shown in Figure 7. As such, the mounting assembly 20 of the pile holder system 10 can be positioned closer to the crane 800 without the pile holder assembly 30 contacting the crane 800 when in the stowed position.

It would be understood that the angle of the pivot axis 43 with respect to the plane 21 of the mounting assembly 20 and the gripping plane 31 of the pile holder assembly 30 may depend on factors including the type of installation, the specific geometries of the pile, the structure and functionality of the crane being used and the available space on the deck. For example on a jack-up vessel piles can be upended with an elliptical trajectory having a larger radius than unsecured vessels due to the additional stability provided by jacking up the vessel. As such the angle of the pivot axis 43 with respect to both planes can be larger.

As an example, the pivot axis 43 may be angled by more than 0 degrees to about 20 degrees with respect to the plane 21 of the mounting assembly 20, aptly from about 5 degrees to about 20 degrees, preferably about 10 degrees. The pivot axis 43 may be angled by more than 0 degrees to about 20 degrees with respect to the gripping plane 31 of the pile holder assembly 30, aptly from about 5 degrees to about 20 degrees, preferably about 10 degrees.

It would be understood that the offset between the pivot points 41 , 42 in the direction that is normal to the gripping plane 31 of the pile holder assembly when the pile holder assembly 30 is in the deployed and stowed positions will depend on the required angle of the pivot axis 43 with respect to the planes 21 , 31 and the lateral spacing between the pivot points 41 , 42.

In this example the pile holding system comprises actuating means. In use, actuation of the actuation means causes the pile holder assembly 30 to pivot about the pivot axis 43 relative to the mounting assembly 20. That is the actuation means can move the pile holder assembly 30 between the deployed position and the stowed position.

In this example, the actuation means comprises actuators 51 , 52 coupled to the pile holder assembly 30 at a position spaced from the pivot axis 43. In this manner when actuated the actuators 51 , 52 apply a force to the pile holder assembly 30 that generates a torque about the pivot axis 43, rotating the pile holder assembly 30 accordingly. In other examples the actuation means may comprise any number of actuators, for example 1 , 3 or more. Alternatively, other types of actuation means may be used, for example a stepper motor.

In this example the actuators 51 , 52 are each coupled to the pile holder assembly 30 via a respective actuator pivot point 53, 54, the actuators 51 , 52 being pivotable at the actuator pivot points 53, 54 about an actuator pivot axis 55 relative to the pile holder assembly 30. The actuator pivot axis 55 is parallel to the pivot axis 43 (as best shown in Figure 3). In this example the pivot points 53, 54 are positioned on flanges extending from the annular pile holder 36.

In this example the actuator pivot point 53 is in the same vertical plane as the pivot point 42. Similarly the actuator pivot point 54 is in the same vertical plane as the pivot point 41. In this manner the rotation of the pile holder assembly 30 is smooth and efficient. However, it would be understood that other arrangements may be possible. In this example, the actuators 51 , 52 are linear actuators that are pivotally coupled to the mounting assembly 20. That is, a first end of each linear actuator 51 , 52 is pivotally coupled to the mounting assembly 20 and a second end of each linear actuator 51 , 52 is pivotally coupled to the pile holder assembly 30. During actuation the linear actuators 51 , 52 extend or retract applying the torque about the pivot axis 43. The linear actuators 51 , 52 pivot about the pivot points at each end thereof as the orientation of the pile holder assembly 30 changes.

Figure 9 illustrates a pile holding assembly 130 that can replace the pile holding assembly 30 in another embodiment of the pile holding system 100. The pile holding assembly 130 shares common features with the pile holding assembly 30. Such features have the same labels are for the pile holding system 10 with the additional prefix 1- and for brevity won’t necessarily be described in detail again.

In this example, the pile holder assembly 130 includes a pile holder support member 137. The pile holder support member 137 is configured to support the annular pile holder member 136 while holding the pile. In this example the pile holder support member 137 has an inner surface for receiving or engaging with the pile. The inner surface is generally aligned with the annulus of the annular pile holder member 136 such that as the pile is held by the annular pile holder member 136 the pile engages with the pile holder support member 137. The inner surface of the pile holder support member 137 may be substantially semi-circular or C-shaped, for example.

The annular pile holder member 136 and the pile holder support member 137 are spaced from each other along the working axis 32 of the pile holder assembly 130. That is, in use, the annular pile holder member 136 is suspended from the pile holder support member 137.

In this example the annular pile holder member 136 and the pile holder support member 137 are connected by means of an actuation system such that the annular pile holder member 136 is movable relative to the pile holder support member 137 in a direction normal to the working axis 32 of the pile holder assembly 130. The actuation system includes a plurality of supports 139i . In this example the supports 139i are rotatable with respect to the pile holder support member 137 and the annular pile holder member 136. For example the supports 139 may be pivotally connected to the pile holder support member 137 and the annular pile holder member 136 with spherical bearings or the like. The actuation system includes at least one actuator 1392, which when actuated changes the relative positions of the annular pile holder member 136 and the pile holder support member 137. The actuation system allows correction of the position of the pile holder member 136 relative to either the pile or the floating vessel or both.

In some embodiments the pile holder support member 137 includes a pile engaging device 170 (for example as shown in Figure 21). The pile engaging device 170 is positioned on, or forms, the inner surface of the pile holder support member 137. In this manner, the pile engaging device 170 provides the engagement between the pile and the pile holder support member 137. In some examples the pile engaging device 170 is a resilient element or formed from a resilient material. This provides dampening of the forces transferred between the pile engaging device 170 and the pile. This reduces the chance of damage to the pile during movement and ensures the motion is as smooth as possible. Any suitable resilient material may be used for the resilient element. For example the resilient material may comprise a composite material comprising at least one of polyester fibers, epoxy resin, graphite or the like.

As with pile holder assembly 30, the pile holder assembly 130 is coupled to the mounting assembly 20 via two pivot points 141 , 142. In this example the pivot points 141 , 142 are on the pile holder support member 137, rather than the annular pile holder member 136. Although not shown actuators equivalent to actuators 51 , 52 may be present, for example coupled to the pile holder support member 137.

Figures 10 to 21 illustrate the pile holding system 10 being used for installing an offshore foundation pile. That is, Figures 10 to 21 show the pile holding system 10 taking an offshore pile 1000 from a position on the deck 501 of the vessel 500 to a deployed position, where it is held by the pile holding system 10 during a piling operation. Figures 10 to 21 show a pile holding system 10 using the pile holding assembly 130. However, it would be understood that a pile holding system 10 using the pile holding assembly 30 works in the same manner.

Figures 10 to 13 show the pile holding system 10 holding a lower end of a pile 1000 with the pile holder assembly 30. The pile 1000 may have been brought into the annulus of the pile holder assembly 30 with a skid system or the like. Typically the jaws 33, 34 will have been open when the pile 1000 was brought into the annulus of the pile holder assembly 30 and then closed around a predetermined longitudinal position of the pile 1000. From this position the offshore pile 1000 is upended by a pile upending tool (not shown). As the pile is upended the pile holder assembly 30 pivots about the pivot axis 43 relative to the mounting assembly 20 between the stowed position and the deployed position. Figures 14 to 17 show the pile 1000 during the upending process. As outlined previously the tip 1001 of the pile 1000 travels in an elliptical path, out of the vertical plane. Figures 18 to 21 show the pile 1000 in a deployed position following rotation of the pile holder assembly 30 about the pivot axis 43. The pile 1000 is held or gripped in place with the pile holding system 10, in a vertical orientation, suspended from the side of the vessel 500.

Referring back to Figures 1 to 3, in the illustrated example the pile holding system further includes a translation system 60. The mounting assembly 20 is mounted on the translation system 60. That is, the mounting assembly 20 is mounted onto the deck of the vessel via the translation system 60.

The mounting assembly 20 is movable along the translation system 60 between a retracted inboard position and an extended outboard position. The pile holding system 10 is shown in the extended outboard position in Figures 4 and 5. Specifically, Figure 4 shows the pile holding system 10 in the extended outboard position, with the pile holding assembly 30 in the deployed position and Figure 5 shows the pile holding system 10 in the extended outboard position, with the pile holding assembly 30 in the stowed position. The pile holding system 10 is shown in the retracted inboard position in Figure 6. Specifically, Figure 6 shows the pile holding system 10 in the retracted inboard position, with the pile holding assembly 30 in the stowed position. In use, the pile holding assembly 30 is rotated from the deployed position to the stowed position before the mounting assembly 20 is moved from the extended position to the retracted position. Retraction of the system, inboard the vessel’s deck when not in use, allows sailing, among other operations, to be performed in a secured manner.

In this example the translation system 60, otherwise termed the track system, includes one or more tracks or rails mounted to the deck of the vessel. The mounting assembly 20 is movable along the tracks. Any suitable mounting between the mounting assembly 20 and the tracks may be used. For example, one or more of the mounting assembly 20 and the tracks may include one or more roller bearings or the like to facilitate movement therebetween. The mounting assembly 20 may be moved along the system in any suitable manner, for example using one or more actuators.

In this example the track system 60 includes a number of parallel rails labelled as 64 to 69. The rails 64 to 69 extend in the inboard/outboard direction allowing movement of the mounting assembly 20 between the retracted position and the extended position. The mounting assembly 20 moves along the tracks 64 to 69 between the extended position and the retracted position.

In this example the track system 60 includes a first track portion 61 and a second track portion 62. The first track portion 61 is positioned between the second track portion 62 and the edge of the vessel 500. The first track portion 61 is itself movable along a lateral rail 63. The lateral rail 63 is positioned at, or towards, the edge of the vessel 500. The lateral rail 63 extends perpendicular to the rails 64 to 69. The lateral rail 63 allows lateral movement of the mounting assembly 20 (via the first track portion 61) during use to dynamically compensate for vessel motion during pile driving. For retraction of the system, the first track portion 61 and the second track portion 62 are laterally aligned so that the rails 64, 65, 66 of the first track portion 61 are aligned with the rails 67, 68, 69 of the second track portion 62. This allows the mounting assembly 20 to fully retract. It would be understood that motion of the mounting assembly 20 along the rails 64, 65, 66 of the first rail portion 61 could also be to compensate for vessel motion.

Various modifications to the above described embodiments are possible. For example, although the pile holding system 10 is shown to include actuation means, movement of the pile holder assembly 30, 130 may result entirely from the upending of the pile 1000, for example with a separate upending device. In addition different configurations of pile holder assembly 30, 130 may be possible.

Although not shown in the illustrated examples, the pile holding system 10 may include a noise mitigation system connected to the lower part of the pile holding assembly 30, 130. This would ensure the pile holding system 10 is a provides a complete functionality and is ready to operate on the installation of the pile. The translation system 60 is only illustrated where the pile holding system 10 includes pile holder assembly 30. It would be appreciated that embodiments where the pile holding system 10 includes pile holder assembly 130 may also include a translation system 60.

Claims

1. A pile holding system for installing an offshore foundation pile into ground, the pile holding system comprising: a mounting assembly for mounting the pile holding system to a marine vessel, the mounting assembly having a plane that is substantially parallel to the deck of the marine vessel, in use; and a pile holder assembly having a gripping plane and a working axis which is normal to the gripping plane, wherein the working axis is substantially aligned with a central axis of a pile during a pile driving operation, wherein the pile holder assembly is coupled to the mounting assembly via at least one pivot point, the pile holder assembly being pivotable at the at least one pivot point about a pivot axis relative to the mounting assembly between a deployed position in which the working axis of the pile holder assembly is substantially vertical and a stowed position in which the working axis is substantially horizontal or substantially parallel with the plane of the mounting assembly, wherein the pivot axis is angled with respect to the plane of the mounting assembly and angled with respect to the gripping plane of the pile holder assembly.

2. The pile holding system according to claim 1 , wherein the pile holding system comprises a connection assembly comprising at least one connection member; wherein the at least one connection member comprises a first end and a second end, wherein the first end of the at least one connection member is connected to, or integral with, the mounting assembly and the second end of the at least one connection member is connected to the pile holder assembly, and wherein the second end of the at least one connection member includes the at least one pivot point.

3. The pile holding system according to claim 1 or 2, wherein the pile holder assembly is coupled to the mounting assembly via a first pivot point and a second pivot point, the pile holder assembly being pivotable at the first pivot point and the second pivot point about the pivot axis relative to the mounting assembly.

4. The pile holding system according to claim 3, wherein the first pivot point and the second pivot point are laterally spaced, wherein the lateral spacing between the first pivot point and the second pivot point is equal to or less than the outer diameter of an annular pile holder of the pile holder assembly.

5. The pile holding system according to any preceding claim, wherein the first pivot point and the second pivot point are offset in a direction that is normal to the gripping plane of the pile holder assembly when the pile holder assembly is in the deployed position.

6. The pile holding system according to any preceding claim, wherein the first pivot point and the second pivot point are offset in a direction that is normal to the gripping plane of the pile holder assembly when the pile holder assembly is in the stowed position.

7. The pile holding system according to any preceding claim, wherein the pile holder assembly comprises an annular pile holder member.

8. The pile holding system according to claim 6, wherein the annular pile holder member comprises at least two jaw elements connectable to each other by locking means.

9. The pile holding system according to any of claim 6 and 7, wherein the pile holder assembly further comprises a pile holder support member configured to support the annular pile holder member while holding the pile.

10. The pile holding system according to claim 9, wherein the pile holder support member comprises a pile engaging device for engaging with the outer surface of the pile.

11. The pile holding system according to claim 10, wherein the pile engaging device comprises a resilient element.

12. The pile holding system according to any of claims 7 to 11 , wherein the annular pile holder member comprises two or more rotatable engagement members for engaging with the outer surface of the pile.

13. The pile holding system according to any of claims 7 to 12, wherein the annular pile holder member and the pile holder support member are spaced from each other along the working axis of the pile holder assembly, wherein the annular pile holder member and the pile holder support member are connected by means of an actuation system such that the annular pile holder member is movable relative to the pile holder support member in a direction normal to the working axis of the pile holder assembly.

14. The pile holding system according to any of claims 2 to 13, wherein the pile holding system comprises actuating means, wherein actuation of the actuation means causes the pile holder assembly to pivot about the pivot axis relative to the mounting assembly.

15. The pile holding system according to claim 14, wherein the actuation means comprises at least one actuator, wherein the at least one actuator is coupled to the pile holder assembly at a position spaced from the pivot axis such that, upon actuation of the at least one actuator, the at least one actuator applies a force to the pile holder assembly that generates a torque about the pivot axis.

16. The pile holding system according to claim 15, wherein the at least one actuator is coupled to the pile holder assembly via an actuator pivot point, the at least one actuator being pivotable at the actuator pivot point about an actuator pivot axis relative to the pile holder assembly, wherein the actuator pivot axis is parallel to the pivot axis.

17. The pile holding system according to claim 16, wherein the actuation means comprises a first actuator and a second actuator, wherein the first actuator is coupled to the pile holder assembly via a first actuator pivot point and the second actuator is coupled to the pile holder assembly via a second actuator pivot point, the first actuator being pivotable at the first actuator pivot point about the actuator pivot axis relative to the pile holder assembly, and the second actuator being pivotable at the second actuator pivot point about the actuator pivot axis relative to the pile holder assembly.

18. The pile holding system according to any preceding claim, wherein the pile holding system further comprises a translation system, wherein the mounting assembly is mounted on the translation system, the mounting assembly being movable along the translation system between a retracted inboard position and an extended outboard position.

19. The pile holding system according to any preceding claim, wherein the pile holding system further comprises a noise mitigation system connected to the lower part of the pile holding assembly.

20. A marine vessel comprising a pile holding system according to any preceding claim, the mounting assembly of the pile holding system being mounted to the marine vessel.

21. Method for installing an offshore foundation pile into ground, wherein the method comprises: providing the pile holding system of any of the preceding claims on a marine vessel; holding a lower end of a pile with the pile holder assembly of the pile holding system; upending the pile, wherein as the pile is upended the pile holder assembly pivots about the pivot axis relative to the mounting assembly between the stowed position and the deployed position.

22. Use of the pile holding system of any of claims 1 to 19 for installing an offshore foundation pile into ground.