Pile Retention System

Abstract

A pile retention system for installation of offshore foundation piles on the seabed is provided. The pile retention system includes a pile gripper assembly, a mounting assembly for mounting the pile retention system to a vessel, a connection assembly including a connecting member, and an actuation means connected to at least one of the pile gripper assembly, the mounting assembly, or the connecting member. The connecting member is pivotally connected to the pile gripper assembly, the connecting member being pivotable relative to the pile gripper assembly about a first pivot axis. The connecting member is pivotally connected to the mounting assembly, the connecting member being pivotable relative to the mounting assembly about a second pivot axis. The first pivot axis and the second pivot axis are substantially parallel. The actuation means is configured to pivot the connecting member about the first and second pivot axes to move the pile gripper assembly relative to the mounting assembly between a first end position and a second end position.

Description

[Technical Field]

[0001] The present invention relates generally to a pile retention system for installing offshore foundation piles, and more particularly, but not exclusively, to a pile retention system for installing offshore monopiles. [Background technology]

[0002] Offshore foundation piles, such as monopiles, are commonly installed by suspending the pile in a vertical position from the side of a vessel for driving into the seabed below the waterline. The pile is typically lowered through the water to the seabed using a crane and is generally held against the side of the vessel by a pile retention system. The pile retention system maintains the pile in a vertical orientation during driving into the seabed. In some cases, the pile retention system supports the pile during deployment and is therefore rotated with the pile when it is inverted by the crane.

[0003] Pile holding systems typically have a pile gripper assembly with jaws that surround the pile. The inner surfaces of the jaws may have rollers for vertically moving the pile through the jaws as the pile is driven into the seabed. Pile holding systems typically have a mounting assembly for attaching the pile holding system to a vessel. In some known systems, the mounting assembly has a translation assembly for dynamically adjusting the lateral position of the pile holding system relative to the vessel, perpendicular to the axis of the pile, to account for vessel movements during pile driving.

[0004] Obviously, due to the large size of offshore foundation piles, pile holding systems are large and occupy a considerable amount of space on a ship. It is preferable to store the pile gripper assembly on board when not in use, and therefore this significant occupation of ship space is exacerbated. Storing the pile gripper assembly on board is sometimes achieved by rotating the pile gripper assembly relative to the mounting assembly so that the plane of the pile gripper assembly, which is perpendicular to the pile when the pile is placed on the pile gripper assembly, is upright. However, due to such a large size, this means that the mounting assembly occupies a large amount of space in the horizontal direction of the ship and the pile gripper assembly occupies a large amount of space in the vertical direction of the ship. This, due to the height of the pile gripper assembly and its orientation on board, hinders work to be performed on board, such as maintenance of the pile gripper assembly. The orientation of the pile gripper assembly on board also increases the complexity of attaching auxiliary equipment to the pile gripper assembly, such as a noise mitigation system.

[0005] It would therefore be advantageous to overcome at least some of these limitations. Summary of the Invention

[0006] Thus, according to a first aspect of the invention, there is provided a pile retention system for installing an offshore foundation pile on a seabed, the pile retention system comprising: a pile gripper assembly; an attachment assembly for attachment of the pile retention system to the vessel; a connection assembly including a connection member; an actuation means connected to at least one of the pile gripper assembly, the mounting assembly, or the connecting member; Equipped with the connecting member is pivotally connected to the pile gripper assembly, the connecting member being pivotable relative to the pile gripper assembly about a first pivot axis; the connecting member is pivotally connected to the mounting assembly, the connecting member being pivotable relative to the mounting assembly about a second pivot axis, the first pivot axis and the second pivot axis being substantially parallel; A pile holding system is provided in which the actuation means is configured to pivot the connecting member about the first pivot axis and the second pivot axis to move the pile gripper assembly between first and second terminal positions relative to the mounting assembly.

[0007] In this system, two points of relative rotation between the pile gripper assembly and the mounting assembly exist, allowing for easy maneuverability. That is, the pile gripper assembly can rotate about both the first and second pivot axes when moving between the first and second terminal positions. Therefore, the pile gripper assembly is maintained in a substantially horizontal orientation during operation and downtime, when the pile gripper assembly is stowed from the outboard position to the inboard position. The pile gripper assembly can be located substantially above the mounting assembly in the inboard position. This results in a more compact solution that occupies less deck space than conventional holding systems. This increases operational flexibility in that additional space is available for other equipment, such as a noise mitigation system suspended below the pile gripper assembly. Additionally, the pile gripper assembly is more easily accessible for maintenance. Furthermore, operating time is substantially reduced.

[0008] In one embodiment, the first pivot axis extends through the pivotable connection point between the connecting member and the pile gripper assembly, and the second pivot axis extends through the pivotable connection point between the connecting member and the mounting assembly, allowing for a very compact system capable of servicing a high volume operation.

[0009] In an embodiment, in the first and second end positions, the angle between the gripping plane of the pile gripper assembly and the plane of the mounting assembly is less than 90°, preferably less than 45°, more preferably less than 10°. The gripping plane may be defined as the plane that, in use, is perpendicular to the longitudinal axis of the gripped offshore foundation pile.

[0010] Because the pile gripper assembly can rotate about both the first pivot axis and the second pivot axis when moving between the first and second terminal positions, rotation of the gripping plane of the pile gripper assembly and the plane of the mounting assembly can be limited. That is, the pile gripper assembly is not stowed onboard by rotating the pile gripper assembly relative to the mounting assembly so that the gripping plane is vertical. Instead, the pile gripper assembly can remain in a substantially horizontal orientation when stowed from the outboard position to the inboard position. As a result, the pile gripper assembly remains more accessible from the deck of the vessel.

[0011] In some embodiments, the plane of the mounting assembly is substantially parallel to the deck of the vessel, which allows for a simpler overall system configuration and allows stresses on critical parts of the system to be better managed and / or limited at both end positions.

[0012] In one embodiment, in the first end position, the second end position, and all positions therebetween, the angle between the gripping plane of the pile gripper assembly and the plane of the mounting assembly is less than 45°, preferably less than 10°.

[0013] In an embodiment, the pile retention system is configured such that the plane of the pile gripper assembly and the plane of the attachment assembly are substantially horizontal during installation of the offshore pile on the seabed, which allows for normal operation of the system during installation of the offshore pile on the seabed while providing better control of the force capacity of the system when in use on a floating vessel.

[0014] In one embodiment, in the first and second end positions, the gripping plane of the pile gripper assembly is substantially parallel to the mounting assembly plane.

[0015] In one embodiment, in all intermediate positions of the pile gripper assembly between the first and second end positions, the gripping plane of the pile gripper assembly is substantially parallel to the plane of the mounting assembly.

[0016] In one embodiment, at the first and second terminal positions, the pile gripper assembly is spaced apart from the mounting assembly.

[0017] This allows auxiliary components, such as noise mitigation systems, to be suspended below the pile gripper assembly while remaining accessible from the vessel deck for maintenance at their onboard locations.

[0018] In one embodiment, the pile gripper assembly is spaced apart from the mounting assembly at the first terminal position, the second terminal position, and all positions therebetween.

[0019] In an embodiment, the connecting member is a primary connecting member and the connecting assembly further comprises a secondary connecting member pivotally connected to at least one of the pile gripper assembly and the attachment assembly. Advantageously, this provides the possibility to use the secondary connecting members to control each of the pile gripper assembly and the attachment assembly for a motion compensation system when pile installation is performed on a floating vessel by having two connecting members to support the pile gripper assembly during motion compensation.

[0020] In one embodiment, the secondary connecting member is pivotally connected to the pile gripper assembly, and the second connecting member is pivotable relative to the pile gripper assembly about a third pivot axis, the third pivot axis being substantially parallel to the first axis and the second axis.

[0021] This arrangement allows the pile gripper assembly to pivot relative to the connection assembly about two separate axes, i.e., the first pivot axis and the third pivot axis, which helps support the pile gripper assembly to remain substantially horizontal during stowage from the outboard position to the inboard position.

[0022] In one embodiment, the secondary connecting member is pivotally connected to the mounting assembly, the connecting member being pivotable relative to the mounting assembly about a fourth pivot axis, the fourth pivot axis being substantially parallel to the first and second axes. This provides a very sturdy yet agile system that can withstand large forces and is therefore easily usable for large pile installation routines.

[0023] In some embodiments, the secondary connection member may be a first secondary connection member, and the pile holding system may include a second secondary connection member. The second secondary connection member may be pivotally connected to the pile gripper assembly. The second secondary connection member may be pivotable relative to the pile gripper assembly about a third pivot axis. The second secondary connection member may be spaced apart from the pivotal connection between the first secondary connection member and the pile gripper assembly. The second secondary connection member may be pivotable relative to the mounting assembly about a fourth pivot axis. The second secondary connection member may be spaced apart from the pivotal connection between the first secondary connection member and the mounting assembly.

[0024] In some embodiments, the primary connection member may be a first primary connection member, and the pile holding system may include a second primary connection member. The second primary connection member may be pivotally connected to the pile gripper assembly. The second primary connection member may be pivotable about a first pivot axis relative to the pile gripper assembly. The second primary connection member may be spaced apart from the pivotal connection between the first primary connection member and the pile gripper assembly. The second primary connection member may be pivotable about a second pivot axis relative to the mounting assembly. The second primary connection member may be spaced apart from the pivotal connection between the first primary connection member and the mounting assembly.

[0025] In some embodiments, the pile retention system may include a cross member connecting the first primary connecting member and the second primary connecting member to one another.

[0026] In some embodiments, any or all of the primary or secondary connecting members may be solid bodies in that no part of the primary or secondary member, respectively, moves relative to any other part of the same primary or secondary connecting member, thereby providing a sturdy assembly with little or minimal movement complications.

[0027] In one embodiment, the first terminal position is an overboard or deployed position and the second terminal position is an onboard or stowed position.

[0028] In some embodiments, the actuation means includes at least one actuation assembly, each of which may include a linear actuator.

[0029] In one embodiment, each of the at least one actuation assembly is pivotally connected at one end to the mounting assembly and at another end to the connecting member.

[0030] In some embodiments, the actuation assembly is pivotable relative to the connecting member about another or fifth pivot axis, the another or fifth pivot axis being substantially parallel to the first and second axes.

[0031] In one embodiment, each of the at least one actuation assembly includes an articulated arm having a first end pivotally connected to the mounting assembly and a second end pivotally connected to the connecting member, wherein the first end of each linear actuator is pivotally connected to the mounting assembly and the second end of each linear actuator is pivotally attached to the articulated arm.

[0032] In some embodiments, each articulated arm may include two sections pivotally connected to one another. A first of the two sections may be pivotally connected to the primary connecting member or to a respective one of the primary connecting members. A second of the two sections may be pivotally connected to the mounting assembly. Each linear actuator may be pivotally connected to the second section of the articulated arm at a location spaced from the pivotal connection between the two sections.

[0033] In some embodiments, the actuation means includes an elongated element, such as a winch with a wire rope. The elongated element may be connected or connectable to the pile gripper assembly and / or the connection assembly. The elongated element may be retractable or releasable to pivot the connection member about first and second pivot axes to move the pile gripper assembly relative to the mounting assembly between first and second terminal positions.

[0034] In one embodiment, the mounting assembly includes a translation assembly including two parallel first rails and two parallel second rails, the first rails and second rails being substantially perpendicular to one another, and the translation assembly including drive means configured to move the pile gripper assembly and the linkage assembly along the first rails and second rails, in use, to provide dynamic position control of the pile gripper assembly.

[0035] In one embodiment, the pile gripper assembly includes articulated jaws configured to, in use, wrap around the periphery of the pile.

[0036] In one embodiment, the pile holding system includes a motion control system configured to compensate for the movement of the vessel to which the offshore foundation pile is attached via the pile gripper assembly in use, and the motion control system may maintain the orientation of the pile gripper assembly relative to the attachment assembly at all times, thereby enabling the pile to be held substantially vertical and in an optimal position when driven into the seabed.

[0037] In one embodiment, the translation assembly is controlled by a motion control system such that the movements of the two parallel first rails and the two parallel second rails are perpendicular to each other.

[0038] In some embodiments, the linear actuator is controllable by a motion control system.

[0039] In one embodiment, the motion control system includes at least one sensor to determine the inclination angle of the pile relative to its vertical axis. The at least one sensor may enable measurement of the pile inclination before and during the pile driving operation. Advantageously, this allows the pile holding system to actively adapt to the vessel's movements, enabling reliable and agile pile driving operations on floating vessels. Furthermore, simultaneous active control of the linear actuator and pile gripper assembly allows precise use of thrusters on floating vessels.

[0040] According to a second aspect of the invention, there is provided a vessel including a pile retention system according to the first aspect of the invention, wherein a mounting assembly for the pile retention system is mounted on the vessel. The mounting assembly may be mounted on a deck of the vessel. The mounting assembly may be mounted above or below the deck of the vessel. The mounting assembly may be mounted substantially parallel to the deck of the vessel.

[0041] According to a third aspect of the invention, there is provided a method of moving a pile gripper assembly of a pile holding system between a first end position and a second end position, comprising the steps of: A method is provided which includes actuating an actuation means of a pile holding system to pivot a connecting member of a connection assembly about a first pivot axis relative to a pile gripper assembly, pivoting the connecting member about a second pivot axis relative to an attachment assembly of the pile holding system, and moving the pile gripper assembly relative to the attachment assembly, wherein the first pivot axis and the second pivot axis are substantially parallel to each other, and wherein the attachment assembly is for attachment of the pile holding system to a vessel.

[0042] In an embodiment, in the first and second end positions, the angle between the gripping plane of the pile gripper assembly and the plane of the mounting assembly is less than 45°, preferably less than 10°. The gripping plane of the pile gripper assembly may, in use, be perpendicular to the longitudinal axis of the gripped offshore foundation pile.

[0043] In one embodiment, in the first and second end positions, the gripping plane of the pile gripper assembly is substantially parallel to the plane of the mounting assembly.

[0044] In one embodiment, during movement between the first and second terminal positions, the plane of the pile gripper assembly is substantially parallel to the plane of the mounting assembly.

[0045] In one embodiment, the pile gripper assembly is maintained in a spaced apart position from the mounting assembly during movement between the first and second terminal positions.

[0046] In one embodiment, the first terminal position is an overboard or deployed position and the second terminal position is an onboard or stowed position.

[0047] In an embodiment, the actuation means includes at least one actuation assembly including a linear actuator, and actuation of the actuation means includes extending or retracting the linear actuator of the at least one actuation assembly.

[0048] In some embodiments, the actuation means includes an elongated element, such as a winch, with a wire rope. The elongated element may be connected or connectable to the pile gripper assembly and / or the connecting assembly. Actuation of the actuation means may include retracting or releasing the elongated element from the winch, pivoting the connecting member about the first and second pivot axes, and moving the pile gripper assembly between first and second terminal positions relative to the mounting assembly.

[0049] In one embodiment, the pile retention system of the third aspect of the invention is the pile retention system of the first aspect of the invention.

[0050] According to a fourth aspect of the present invention, there is provided a method of installing offshore piles using a pile retention system mounted on a vessel, comprising the steps of: gripping the offshore pile with a pile gripper assembly; moving a pile retention system from a second terminal position to a first terminal position according to the previous aspect of the invention, the second terminal position being a stowed position and the first terminal position being a deployed position; Piling work is carried out to drive the offshore piles into the seabed. A method is provided, comprising:

[0051] In one embodiment, the method includes actuating a drive means to move the pile gripper assembly and the connection assembly along substantially vertical first and second rails of a translation assembly included in the mounting assembly, the translation assembly also including the drive means to provide dynamic position control of the pile gripper assembly relative to the vessel when installing the pile. Advantageously, this can be used to account for vessel motion, for example when the vessel is floating and is therefore displaced by waves and currents. Additionally or alternatively, this can be used to account for wave and current loads on the foundation pile to maintain the foundation pile within an inclination tolerance.

[0052] In an embodiment, gripping the offshore pile includes gripping the offshore pile between articulated jaws of a pile gripper assembly that surrounds the periphery of the offshore pile.

[0053] For the avoidance of doubt, any feature described herein applies equally to all aspects of the invention. For example, a method may include any one or more features or steps relating to one or more features of a pile retention system.

[0054] Within the scope of this application, it is expressly intended that the various aspects, embodiments, examples, and alternatives, and in particular individual features thereof, set forth in the preceding paragraphs, claims, and / or the following description and drawings may be employed independently or in any combination. That is, all embodiments and / or features of any embodiments may be combined in any manner and / or combination, unless such features are incompatible. For the avoidance of doubt, the terms "may," "and / or," "for example," "for example," and any similar terms used herein should be interpreted open-endedly, in that not every feature so described needs to be present. Indeed, all combinations of optional features, whether explicitly claimed or not, are expressly contemplated without departing from the scope of the invention. Applicant reserves the right to modify any claims as filed or to file any corresponding new claims, including the right to amend any claims as filed to rely on and / or incorporate any feature of any other claim, even if not claimed in that form at the time of filing.

[0055] Embodiments of the invention will now be described, by way of example only, with reference to the accompanying drawings, in which: [Brief explanation of the drawings]

[0056] [Figure 1a] FIG. 1 is a schematic diagram of a pile retention system. [Figure 1b] FIG. 1 is a schematic diagram of a pile retention system. [Figure 1c] FIG. 1 is a schematic diagram of a pile retention system. [Figure 1d] FIG. 1 is a schematic diagram of a pile retention system. [Figure 2a] FIG. 1B is a schematic diagram of the pile retention system of FIGS. 1a-1d with the addition of a noise mitigation system. [Figure 2b] FIG. 1B is a schematic diagram of the pile retention system of FIGS. 1a-1d with the addition of a noise mitigation system. [Figure 2c] FIG. 1B is a schematic diagram of the pile retention system of FIGS. 1a-1d with the addition of a noise mitigation system. [Figure 2d] FIG. 1B is a schematic diagram of the pile retention system of FIGS. 1a-1d with the addition of a noise mitigation system. [Figure 3a] FIG. 10 is a schematic diagram of another pile retention system. [Figure 3b] FIG. 10 is a schematic diagram of another pile retention system. DETAILED DESCRIPTION OF THE INVENTION

[0057] 1a-1d, there is shown a pile retention system 1 for installing an offshore foundation pile (not shown) on the seabed (not shown). The pile retention system 1 includes a pile gripper assembly 2 and a mounting assembly 3. In this example, the mounting assembly 3 is mounted on deck D of the vessel, although the mounting assembly may also be mounted above or below deck D. Preferably, the mounting assembly 3 is mounted substantially parallel to deck D. The pile retention system 1 is mounted to the side of the vessel such that the pile retention system 1 can extend beyond the boundary of the vessel.

[0058] The pile gripper assembly 2 is connected to the mounting assembly 3 via a connection assembly. In this example, the connection assembly has a first primary connection member 41 and a second primary connection member 41 spaced apart from each other. In this example, a cross member 41a is provided connecting the two primary connection members 41 to each other. However, the cross member 41a is optional. In this example, each primary connection member 41 is a solid object, such as a rod, beam, or bar. It should be understood that any number of primary connection members may be provided, for example, there may be only one primary connection member.

[0059] The primary connection member 41 is pivotally connected at a first end to the pile gripper assembly 2. The primary connection member 41 is pivotally connected at a second end to the mounting assembly 3. The primary connection member 41 is pivotable about a first pivot axis A1 relative to the pile gripper assembly 2. The primary connection member 41 is pivotable about a second pivot axis A2 relative to the mounting assembly 3. The first pivot axis A1 and the second pivot axis A2 are substantially parallel to each other.

[0060] In this example, the connection assembly includes a first secondary connection member 42 and a second secondary connection member 42. Each secondary connection member 42 is a solid object, such as a rod, beam, or bar. The secondary connection members 42 are pivotally connected at a first end to the pile gripper assembly 2. The secondary connection members 42 are pivotally connected at a second end to the mounting assembly 3.

[0061] In this example, the two secondary connection members 42 have a common pivotable connection to the pile gripper assembly 2 and separate pivotable connections to the mounting assembly 3, such that the secondary connection members 42 diverge from one another in a direction away from the first end toward the second end. In this example, the two secondary connection members 42 are connected to one another by a cross member 42a proximal to their pivotable connections to the mounting assembly 3. It should be understood that either or both of the common pivotable connection to the pile gripper assembly 2 and the cross member 42a may be omitted. For example, the two secondary connection members 42 may be generally spaced apart so as to be substantially parallel. It should be understood that the secondary connection member 42 may be omitted entirely, such that the pile gripper assembly 2 simply pivots relative to the primary connection member 41.

[0062] The secondary connection member 42 is pivotable about a third pivot axis A3 relative to the pile gripper assembly 2. The secondary connection member 42 is pivotable about a fourth pivot axis A4 relative to the mounting assembly 2. The third pivot axis A3 and the fourth pivot axis A4 are substantially parallel to each other and to the first pivot axis A1 and the second pivot axis A2.

[0063] The pile retention system 1 includes actuation means, which in this example includes two actuation assemblies, each having a linear actuator 51 and an articulated arm formed from a first portion 52a and a second portion 52b.

[0064] Each linear actuator 51 is pivotally connected at one end to the mounting assembly 3 and at the other end to a respective articulated arm. In each articulated arm, an end of the first portion 52a and an end of the second portion 52b are pivotally connected to each other. The other end of the first portion 52a of each articulated arm is pivotally connected to the mounting assembly 3 at another location to the pivotal connection between the respective linear actuator 51 and the mounting assembly 3. The other end of the second portion 52b of each articulated arm is pivotally connected to a respective one of the primary connecting members 41 such that the second portion 52b of each articulated arm is pivotable about a fifth pivot axis A5 relative to the respective primary connecting member 41. The fifth pivot axis A5 is spaced apart from and parallel to the first, second, third, and fourth pivot axes A1, A2, A3, and A4. Each linear actuator 51 is pivotally connected to a respective articulated arm first portion 52a at a distance along the length of the first portion 52a. In this example, the first portions 52a of the two articulated arms are connected to one another via a cross member 52c. However, the cross member 52c is optional.

[0065] The actuation means may alternatively be provided by a winch (not shown). An elongated element such as a wire rope or winch is connected or connectable to the pile gripper assembly 2 such that retraction or release of the wire rope causes the pile gripper assembly 2 to move relative to the mounting assembly.

[0066] The pile gripper assembly 2 has openable and closable jaws 21 that define a substantially circular path when closed. The jaws 21 are openable and closable so that an offshore pile (not shown) can be placed into or gripped by the jaws 21 of the pile gripper assembly 2. In this example, the pile gripper assembly 2 has a plurality of roller devices 22 arranged around the circular path. When the jaws 21 are closed around the pile, the pile is gripped by the roller devices 22, which allows it to move axially but prevents it from moving in other directions. In this way, the pile gripper assembly 2 can be used to hold the pile vertically as it is driven into the seabed during a pile driving operation.

[0067] In one embodiment, the mounting assembly 3 includes a mounting frame for mounting the pile gripper assembly 2 and the connection assembly to the deck D. The mounting frame may fix the pile retention system 1 relative to the deck D. However, in other examples, the mounting frame may allow the pile retention system 1 to move relative to the deck D.

[0068] In this example, the mounting assembly 3 includes a translating assembly having two parallel first rails 31 and two parallel second rails 32. The first rails 31 are substantially perpendicular to the second rails 32. The first rails 31 are mountable to the vessel. In this example, the first rails 31 are mounted to deck D of the vessel, but as previously mentioned, it should be understood that the first rails 31 may be mounted in another manner, such as to another structure above deck D, or may be mounted below deck D.

[0069] In this example, the first rail 31 and the second rail 32 are coupled to each other by a moving device, such as a movable carriage.

[0070] In this example, the movement device moves the second rail 32 along the axial direction of the first rail 31. In this example, the movement device is a biaxial coupling in that it also moves the second rail 32 in the axial direction of the second rail 32. That is, the second rail 32 is moved transversely across the first rail 31 along their longitudinal axes relative to the movement device. In this way, the second rail 32 can move in a first direction (axial direction of the first rail 31) and a second direction (axial direction of the second rail 32).

[0071] In this example, the mounting assembly 3 includes actuatable drive means for driving movement of the second rail 32 and / or the movement device along the axial direction of the first rail 31 and the axial direction of the second rail 32. The drive means may include a motor or the like. The drive means may be coupled to the second rail 32 or the movement device. In this example, the drive means is controlled by a motion control system (not shown). The motion control system drives the drive means in response to one or more sensors that measure the inclination of the foundation piles during pile driving application to maintain the foundation piles in a substantially vertical orientation. Other sensors may also be present to measure the position and / or orientation of the vessel, and the motion control system may use these additional measurements to control the drive means.

[0072] In this example, the primary connection member 41, the secondary connection member 42, the linear actuator 51, and the first portion 52a of the articulated arm are all pivotally connected to the second rail 32. It should be understood that this connection may be direct, as shown in the illustrated example, or indirect, for example, via an intermediate platform. In this manner, movement of the second rail 32 relative to the first rail 31 causes movement of the pile gripper assembly 2. This allows the position of the pile gripper assembly 2 relative to the vessel to be adjusted or dynamically controlled to take into account vessel movements during pile driving operations, thereby maintaining the offshore pile in a vertical orientation despite vessel movements and / or loads on the foundation pile caused, for example, by waves or currents. It should be understood that in other, more simplified examples, the mounting assembly may allow movement of the pile gripper assembly 2 relative to the deck D only in one direction, or may not allow movement at all.

[0073] Figures 1a and 1c show the pile holding system 1 in a first terminal position. In this example, the first terminal position is the outboard or deployed position. Figures 1b and 1d show the pile holding system 1 in a second terminal position. In this example, the second terminal position is the onboard or stowed position. In the outboard position, the pile gripper assembly 2 is outboard of the vessel and is available for pile driving applications, as previously described. When pile driving operations are not being performed, the pile gripper assembly 2 is stored in the onboard position.

[0074] The pile gripper assembly 2 includes a plane or gripper plane P1 that is perpendicular to the axis of the circular path of the pile gripper assembly 2 and therefore perpendicular to the pile axis during the pile driving operation. The gripper plane P1 is shown in Figure 1b.

[0075] In the illustrated example, in both the inboard and outboard positions, the orientation of the gripper plane P1 of the pile gripper assembly 2 remains substantially constant relative to a fixed reference point on the vessel. For example, in both the inboard and outboard positions, the gripper plane P1 of the pile gripper assembly 2 remains substantially parallel to the vessel's deck D or the plane P2 of the mounting assembly, which is also perpendicular to the axis of the pile during the pile driving operation, as also shown in Figure 1b.

[0076] The parallel orientation of the pile gripper assembly 2 with respect to deck D in the inboard position is advantageous because it simplifies access to the pile gripper assembly 2 for maintenance and for installing auxiliary equipment such as a noise mitigation system (NMS). This orientation is also an efficient use of space because the volume of space above deck D of the vessel occupied by the pile holding system 1 is not significantly larger in the inboard position than in the outboard position. It should be understood that the planes P1, P2 of the pile gripper assembly 2 and the mounting assembly 3 do not have to be parallel to achieve these advantages. It should also be understood that the angle between planes P1, P2 can be provided by varying the relative lengths of the primary connecting member 41 and the secondary connecting member 42. However, it is preferred that the angle between planes P1, P2 be less than 45°, and more preferably less than 10°.

[0077] The movement of the pile retaining system 1 between the onboard and outboard positions shown in Figures 1b, 1d and 1a, 1c respectively when the pile retaining system 1 is installed on a vessel will now be described.

[0078] Starting from the outboard position, the linear actuators 51 are actuated to extend linearly. This causes the first portion 52a of each articulated arm to pivot about its pivotable connection to the attachment assembly 3, thereby moving the second portion 52b of the articulated arm in the inboard direction. The movement of the second portion 52b of the articulated arm causes the primary connection member 41 to pivot about the second axis A2 relative to the attachment assembly, thereby pivoting the primary connection member 41 in the inboard direction. The primary connection member 41 also pivots about the first pivot axis A1 relative to the pile gripper assembly. The movement of the primary connection member 41 first lifts the pile gripper assembly 2 and then lowers it to the inboard position. Due to the pivotable connection at each end of the second portion 52b of each articulated arm, the second portions 52b are free to pivot and are loaded in tension, lifting the primary connection member 41 away from the outboard position. When the primary connecting member 41 passes the rotation point where the line of the supported weight passes through the second pivot axis A2, the second portion 52b of the articulated arm is compressed, lowering the pile gripper assembly 2 to the onboard position and supporting the pile gripper assembly 2 in the onboard position.

[0079] Starting from the inboard position, the linear actuators 51 are actuated to linearly retract. This causes the first portion 52a of each articulated arm to pivot about its pivotable connection to the attachment assembly 3, thereby moving the second portion 52b of the articulated arm in the outboard direction. The movement of the second portion 52b of the articulated arm causes the primary connection member 41 to pivot about the second axis A2 relative to the attachment assembly, thereby pivoting the primary connection member 41 in the outboard direction. The primary connection member 41 pivots about the first pivot axis A1 relative to the pile gripper assembly. The movement of the primary connection member 41 first lifts the pile gripper assembly 2 and then lowers it to the outboard position. Due to the pivotable connection at each end of the second portion 52b of each articulated arm, the second portions 52b are free to pivot and are compressed, lifting the primary connection member 41 away from the inboard position. When the primary connecting member 41 passes the rotation point where the line of the supported weight passes through the second pivot axis A2, the second portion 52b of the articulated arm is loaded in tension, lowering the pile gripper assembly 2 to the outboard position and supporting the weight of the pile gripper assembly 2 in the outboard position.

[0080] In both directions of movement, rotation of the pile gripper assembly 2 relative to the mounting assembly 3 is controlled by the pivotable connection of the pile gripper assembly 2 and the mounting assembly 3 to the secondary connecting member 42 about the third axis A3 and the fourth axis A4, respectively.

[0081] A possible variation of this embodiment of the pile holding system is that the secondary connecting member 42 may be an actuator so that the angle of the plane of the pile gripper assembly 2 is adjustable. This may be advantageous for maintenance purposes or to maintain a particular angle between the plane of the pile gripper assembly and the plane of the mounting assembly when moving between the inboard and outboard positions. As mentioned above, another variation is for the actuation assembly to be replaced by one or more winches, the elongated elements of which are connectable to the pile gripper assembly 2. In this case, the winches are operable to raise and lower the pile gripper assembly 2 between the inboard and outboard positions.

[0082] 2a-2d, the pile holding system 1 of FIG. 1 is shown with a noise mitigation system (NMS) attached to the pile gripper assembly 2. As is evident from FIGS. 2b and 2d, the orientation of the pile gripper assembly 2 at its onboard location greatly facilitates the attachment and detachment of the NMS 6 to and from the pile gripper assembly 2. The NMS 6 can be a hydrosound damper (HSD) system or a system of resonators tuned to specific frequencies.

[0083] The structure and operation of the pile retention system 1 fitted with the NMS 6 is the same as that described with respect to FIG.

[0084] 3a-3b, there is shown a pile retention system 11 according to another embodiment of the invention. This pile retention system 11 is similar to the pile retention system 1 of the previous embodiment, and like features are indicated with like reference numerals preceded by a "1".

[0085] The pile holding system 11 of this embodiment differs from that of the previous embodiment in that two linear actuators 151 are pivotally connected directly to the cross member 141a that connects the two primary connecting members 141. Therefore, there are no articulated arms in the pile holding system 11 of this embodiment.

[0086] The primary connection members 141 of this embodiment also differ from those of the previous embodiment in that each is generally triangular and formed by three elongated sections, each joined at a respective end to a respective one of the other two elongated members. A first elongated member of each primary connection member 141 has a pivotable connection at one end to the mounting assembly 13 and a pivotable connection at the other end to the pile gripper assembly 2. A second one of the elongated members of each primary connection member 141 has a pivotable connection at one end to the mounting assembly 13 and a cross member 141 a at the other end. A third one of the elongated members of each primary connection member 141 has a pivotable connection at one end to the pile gripper assembly 2 and a cross member 141 a at the other end.

[0087] It should be understood that other variations in the shape, configuration, or number of the primary connecting members 41, 141, secondary connecting members 42, 142, and linear actuators 51, 151, respectively, are possible.

[0088] The mounting assembly 13 is substantially the same as that of the previous embodiment, with the pivotable connection between the primary connecting member 141 , the secondary connecting member 142 and the linear actuator 151 comprising a second rail 132 .

[0089] The pile gripper assembly 22 and the secondary connecting member 142 are substantially the same as those in the previous embodiment and will not be described further. The operation of the pile gripper assembly 22 and the mounting assembly 13 is also the same as that previously described and will not be described further. As can be seen from Figures 3a and 3b, the NMS 16 is present in the pile gripper assembly 22, as in the case of Figures 2a-2d. However, as in the embodiment of Figures 1a-1d, the NMS 16 can be omitted.

[0090] Movement of the pile gripper assembly 22 between the outboard and inboard positions will now be described.

[0091] Starting from the outboard position, the linear actuator 151 is actuated to extend linearly, thereby pressing the cross members 141a connecting the primary connection members 141 in the inboard direction, thereby causing the primary connection members 141 to pivot about the second pivot axis A12 relative to the mounting assembly 13. This in turn lifts the pile gripper assembly 22, causing the primary connection members 141 to pivot about the first pivot axis A11 relative to the pile gripper assembly 22. Continued extension of the linear actuator 151 lowers the pile gripper assembly 22 to the inboard position.

[0092] Starting from the inboard position, the linear actuator 151 is actuated to linearly retract, which pulls the cross members 141a connecting the primary connection members 141 in the outboard direction, thereby causing the primary connection members 141 to pivot about the second pivot axis A12 relative to the mounting assembly 13. This, in turn, lifts the pile gripper assembly 22, causing the primary connection members 141 to pivot about the first pivot axis A11 relative to the pile gripper assembly 22. Continued extension of the linear actuator 151 lowers the pile gripper assembly 22 to the outboard position.

[0093] As in the previous embodiment, rotation of the pile gripper assembly 22 relative to the mounting assembly 13 in both directions of movement is maintained by the pivotable connection of the pile gripper assembly 22 and the mounting assembly 13 to the secondary connecting member 142 about the third axis A13 and the fourth axis A14, respectively.

[0094] As in the previous embodiment, a possible variation is that the secondary connecting member 142 can be an actuator so that the angle of the plane of the pile gripper assembly 22 is adjustable. This can be advantageous for maintenance purposes or to maintain a particular angle when moving between inboard and outboard positions.

Claims

1. 1. A pile retention system for installing offshore foundation piles on a seabed, the pile retention system comprising: a pile gripper assembly; a mounting assembly for mounting the pile retention system to a vessel; a connection assembly including a connection member; an actuation means connected to at least one of the pile gripper assembly, the mounting assembly, or the connecting member; Equipped with the connecting member is pivotally connected to the pile gripper assembly, the connecting member being pivotable relative to the pile gripper assembly about a first pivot axis; the connecting member is pivotally connected to the mounting assembly, the connecting member being pivotable relative to the mounting assembly about a second pivot axis, the first pivot axis and the second pivot axis being substantially parallel; the actuation means is configured to pivot the connecting member about the first pivot axis and the second pivot axis to move the pile gripper assembly between first and second end positions relative to the mounting assembly.

2. 2. The pile holding system according to claim 1, wherein in the first and second end positions, the angle between the gripping plane of the pile gripper assembly and the plane of the mounting assembly is less than 45°, preferably less than 10°.

3. 3. The pile holding system according to claim 1 or 2, wherein in the first and second end positions, the gripping plane of the pile gripper assembly is substantially parallel to the plane of the mounting assembly.

4. 4. The pile holding system of claim 3, wherein at all intermediate positions of the pile gripper assembly between the first and second terminal positions, the gripping plane of the pile gripper assembly is substantially parallel to the plane of the mounting assembly.

5. 5. The pile holding system of claim 1, wherein at the first and second end positions, the pile gripper assembly is spaced apart from the mounting assembly.

6. 6. The pile holding system of claim 1, wherein the connecting member is a primary connecting member, and the connecting assembly further includes a secondary connecting member pivotally connected to at least one of the pile gripper assembly and the mounting assembly.

7. 7. The pile holding system of claim 6, wherein the secondary connection member is pivotally connected to the pile gripper assembly, the secondary connection member being pivotable relative to the pile gripper assembly about a third pivot axis, the third pivot axis being substantially parallel to the first axis and the second axis.

8. 8. The pile retention system of claim 6 or 7, wherein the secondary connecting member is pivotally connected to the mounting assembly, the connecting member being pivotable relative to the mounting assembly about a fourth pivot axis, the fourth pivot axis being substantially parallel to the first and second axes.

9. 9. A pile retention system according to any one of claims 1 to 8, wherein the first terminal position is an outboard or deployed position and the second terminal position is an onboard or stowed position.

10. 10. The pile retention system of claim 1, wherein the actuation means comprises at least one actuation assembly, each actuation assembly comprising a linear actuator.

11. 11. The pile retention system of claim 10, wherein each of the at least one actuation assembly is pivotally connected at one end to the mounting assembly and at another end to the connecting member.

12. 12. The pile retention system of claim 11, wherein each of the at least one actuation assembly includes an articulated arm having a first end pivotally connected to the mounting assembly and a second end pivotally connected to the connecting member, the first end of each linear actuator being pivotally connected to the mounting assembly and the second end of each linear actuator being pivotally connected to the articulated arm.

13. 13. The pile holding system of any one of claims 1 to 12, wherein the mounting assembly includes a translating assembly including two parallel first rails and two parallel second rails, the first rails and the second rails being substantially perpendicular to one another, and the translating assembly including drive means configured to move the pile gripper assembly and linkage assembly along the first rails and the second rails, in use, to provide dynamic positional control of the pile gripper assembly.

14. 14. The pile retention system of claim 13, further comprising a motion control system configured to compensate, in use, for movement of a vessel to which the offshore foundation pile is attached via the pile gripper assembly.

15. 15. The pile retention system of claim 14, wherein the translation assembly is controlled by the motion control system such that the motion of the two parallel first rails and the two parallel second rails is perpendicular to one another.

16. 16. A pile holding system according to any preceding claim, wherein the pile gripper assembly includes articulated jaws configured to, in use, encircle the periphery of the pile.

17. A vessel comprising a pile retention system according to any one of claims 1 to 16, wherein the mounting assembly of the pile retention system is mounted on the vessel.

18. 1. A method for moving a pile gripper assembly of a pile holding system between a first end position and a second end position, comprising: activating an actuation means of the pile holding system to pivot a connecting member of a connection assembly about a first pivot axis relative to the pile gripper assembly, to pivot the connecting member about a second pivot axis relative to an attachment assembly of the pile holding system, and to move the pile gripper assembly relative to the attachment assembly, wherein the first pivot axis and the second pivot axis are substantially parallel to each other, and the attachment assembly is for attaching the pile holding system to a vessel.

19. 19. The method according to claim 18, wherein the pile gripper assembly has a gripping plane, the gripping plane of the pile gripper assembly being perpendicular to a longitudinal axis of a gripped offshore foundation pile in use, and wherein in the first and second end positions an angle between the gripping plane of the pile gripper assembly and the plane of the mounting assembly is less than 45°, preferably less than 10°.

20. 20. The method of claim 19, wherein in the first and second terminal positions, the gripping plane of the pile gripper assembly is substantially parallel to the plane of the mounting assembly.

21. 21. The method of claim 20, wherein during movement between the first and second terminal positions, the plane of the pile gripper assembly is substantially parallel to the plane of the mounting assembly.

22. 22. A method according to any one of claims 18 to 21, wherein the pile gripper assembly is maintained in a spaced apart position from the mounting assembly during movement between the first and second terminal positions.

23. 23. A method according to any one of claims 18 to 22, wherein the first terminal position is an overboard or deployed position and the second terminal position is an onboard or stowed position.

24. 24. The method of any one of claims 18 to 23, wherein the actuation means comprises at least one actuation assembly including a linear actuator, and actuation of the actuation means comprises extending or retracting the linear actuator of the at least one actuation assembly.

25. 1. A method of installing offshore piles using a pile retention system mounted on a vessel, comprising: gripping the offshore pile with a pile gripper assembly; 23. Moving the pile retention system according to any one of claims 16 to 22 from a second terminal position to a first terminal position, the second terminal position being a stowed position and the first terminal position being a deployed position; carrying out piling work to drive the offshore pile into the seabed; A method comprising:

26. 26. The method of claim 25, comprising actuating drive means to move the pile gripper assembly and the connection assembly along substantially vertical first and second rails of a translating assembly included in the mounting assembly, the translating assembly also including the drive means to provide dynamic positional control of the pile gripper assembly relative to the vessel when installing the pile.

27. 27. A method according to claim 25 or 26, wherein gripping the offshore pile comprises gripping the offshore pile between working jaws of the pile gripper assembly surrounding the periphery of the offshore pile.

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