Offshore installation system and method for handling a monopile and a monopile transportation vessel

Abstract

An offshore installation system (100) for handling a monopile comprises a monopile transportation vessel (102) configured to transport the monopile in a horizontal position. A monopile handling mechanism (132) is mounted on the transportation vessel (102) and is configured to secure the monopile during transportation and move it to an inclined position. The system also includes an offshore installation vessel with a hull (122) and a plurality of moveable legs (126), wherein the hull is positioned out of the water when the moveable legs engage the seafloor. A push down stabilising mechanism (130) is mounted on the offshore installation vessel and is configured to apply a downward force on the monopile transportation vessel to increase its buoyancy force when positioned underneath the hull, stabilising the monopile transportation vessel and the inclined monopile with respect to the offshore installation vessel.

Description

[0001] Offshore monopile transportation and handling system and method

[0002] Field

[0003] The technology relates to the field of offshore wind energy, specifically to the transportation, handling, and installation of monopiles for offshore wind turbine foundations and wind turbine generator (WTG) towers.

[0004] Background

[0005] Offshore wind turbine generators are an essential source of renewable energy, providing clean and sustainable power to various regions around the world. These wind turbines are typically installed on large structures known as monopiles, which are driven into the seafloor to provide a stable foundation for the wind turbine generators. As the size and capacity of offshore wind turbine generators increase, the monopiles also become larger and heavier, posing significant challenges in their transportation and installation at offshore sites.

[0006] Traditionally, monopiles have been transported to offshore installation sites on barges, either in a vertical or horizontal orientation. Transporting monopiles in a vertical orientation requires very calm weather conditions to ensure the stability and safety of the barge and the monopile. However, calm weather is not always feasible, and adverse weather conditions can lead to dangerous situations, such as the monopile tipping over or causing damage to the barge. This weather dependency limits the operational windows for transportation, causing delays and increasing the complexity of logistics.

[0007] Alternatively, monopiles can be transported in a horizontal orientation. However, this approach necessitates upending the monopiles to a vertical position at the installation site, which can be difficult in adverse weather conditions. The upending process requires large cranes and precise handling, which can be challenging to achieve in rough seas. The complexity of this operation increases the risk of accidents and delays, as well as the need for highly skilled personnel and specialised equipment. Furthermore, the transportation of large monopiles requires specialised vessels that can accommodate their size and weight, whether in a vertical or horizontal orientation. The limited availability of such vessels can lead to scheduling conflicts, increased costs, and logistical challenges. Additionally, the design and construction of these vessels must account for the specific requirements of monopile transportation, further complicating the process.

[0008] Summary

[0009] According to a first aspect of the disclosure, an offshore installation system for handling a monopile comprises a monopile transportation vessel configured to transport the monopile in a horizontal position. The system further comprises a monopile handling mechanism mounted on the monopile transportation vessel and configured to secure the monopile during transportation and to move the monopile to an inclined position. Additionally, the system comprises an offshore installation vessel having a hull and a plurality of moveable legs, wherein the hull is positioned out of the water when the moveable legs engage the seafloor. The system also comprises a push down stabilising mechanism mounted on the offshore installation vessel and configured to apply a downward force on the monopile transportation vessel to increase a buoyancy force on the monopile transportation vessel when the monopile transportation vessel is positioned underneath the hull to stabilise the monopile transportation vessel and the inclined monopile with respect to the offshore installation vessel. This provides a stable and controlled environment for handling and installing monopiles, even in challenging offshore conditions.

[0010] Optionally in some examples, the monopile handling mechanism is configured to move the monopile from the inclined position towards a vertical position after the push down stabilising mechanism exerts the push down force on the monopile transportation vessel. This feature allows for a seamless transition of the monopile from an inclined to a vertical position, facilitating easier and more efficient installation. This enhances the efficiency and safety of the monopile installation process by ensuring a controlled and stable transition to the vertical position. Optionally in some examples, the monopile handling mechanism comprises a first monopile handling mechanism configured to engage a monopile lower portion and a second monopile handling mechanism configured to engage a monopile upper portion. This dual-handling mechanism ensures that both the upper and lower portions of the monopile are securely managed during the transition from horizontal to inclined positions.

[0011] Optionally in some examples, the first monopile handling mechanism is configured to slide and pivot the monopile lower portion as the monopile moves from the horizontal position to the inclined position. This sliding and pivoting action allows for a smooth and controlled movement of the monopile, minimising stress and potential damage. This ensures a smooth and controlled transition of the monopile, reducing the risk of structural stress and potential damage.

[0012] Optionally in some examples, the second monopile handling mechanism is configured to raise the monopile upper portion as the monopile moves from the horizontal position to the inclined position. This feature ensures that the upper portion of the monopile is elevated appropriately during the transition, facilitating a smooth and controlled movement. This provides additional control and stability during the transition, ensuring the monopile is correctly positioned for installation.

[0013] Optionally in some examples, the system further comprises a hydraulic control system configured to control and manage hydraulic components of the monopile handling mechanism. This hydraulic control system ensures precise and reliable operation of the various hydraulic components involved in handling the monopile.

[0014] Optionally in some examples, the offshore installation vessel comprises a cut-out in the hull configured to align with the monopile handling mechanism when the monopile transportation vessel is positioned underneath the hull and when the monopile is in an inclined position. This cut-out allows for the inclined monopile to be received when the monopile installation vessel is underneath the offshore installation vessel. This means the height of the inclined monopile does not interfere with the hull of the offshore installation vessel. Optionally in some examples, the push down stabilising mechanism comprises a plurality of push down engagement portions configured to engage a surface of the monopile transportation vessel and apply the downward force. These engagement portions ensure an even distribution of the downward force, enhancing the stability and control of the monopile transportation vessel.

[0015] Optionally in some examples, the push down engagement portions are configured to engage a vessel deck of the monopile transportation vessel.

[0016] Optionally in some examples, the system further comprises a monopile gripper mounted on the offshore installation vessel and configured to grip and secure the monopile for handling and installation. This gripper ensures that the monopile can be securely held and manipulated during the installation process.

[0017] Optionally in some examples, the monopile transportation vessel comprises a vessel deck having a reciprocal deck receiving portion configured to receive and secure feet portions of the stabilising mechanism. This feature ensures that the push down stabilising mechanism can be securely anchored to the monopile transportation vessel, enhancing stability during the handling process.

[0018] Optionally in some examples, the monopile handling mechanism comprises a lashing mechanism configured to secure the monopile to the first monopile handling mechanism during transport. This lashing mechanism ensures that the monopile remains securely fastened to the handling mechanism, preventing movement or shifting during transport.

[0019] Optionally in some examples, the monopile handling mechanism comprises a skidding sea fastening support configured to securely fasten the second monopile handling mechanism to the vessel deck when the monopile is in the horizontal position. This fastening support ensures that the second monopile handling mechanism remains securely anchored to the vessel deck, preventing movement or shifting during transport. According to a second aspect of the disclosure, a method of moving and handling a monopile at an offshore installation vessel comprises transporting the monopile on a monopile transportation vessel to the offshore installation vessel. The method further comprises moving the monopile on the monopile transportation vessel from a horizontal position to an inclined position with a monopile handling mechanism. Additionally, the method comprises aligning the monopile transportation vessel underneath the hull of the offshore installation vessel. The method also comprises exerting a force on the monopile transportation vessel with a push down stabilising mechanism mounted on the offshore installation vessel to increase the buoyancy force on the monopile transportation vessel. Finally, the method comprises stabilising the monopile transportation vessel and the inclined monopile with respect to the offshore installation vessel.

[0020] Optionally in some examples, the method further comprises moving the monopile from the inclined position towards a vertical position with the monopile handling mechanism after the push down stabilising mechanism exerts the push down force on the monopile transportation vessel. This step ensures a smooth and controlled transition of the monopile from an inclined to a vertical position, facilitating easier and more efficient installation.

[0021] According to a third aspect of the disclosure, a monopile transportation vessel configured to transport a monopile in a horizontal position comprises a monopile handling mechanism mounted on the vessel and configured to secure the monopile during transportation and to move the monopile to an inclined position at an offshore installation vessel. The monopile handling mechanism comprises a first monopile handling mechanism configured to engage a monopile lower portion and a second monopile handling mechanism configured to engage a monopile upper portion. Additionally, the vessel comprises a vessel deck configured to receive push down engagement portions of a push down stabilising mechanism mounted on an offshore installation vessel arranged to increase a buoyancy force on the monopile transportation vessel when the monopile transportation vessel is positioned underneath the hull of the offshore installation vessel such that the monopile transportation vessel and the inclined monopile are stabilised with respect to the offshore installation vessel. Brief of the Drawinqs

[0022] Examples are described in more detail below with reference to the appended drawings.

[0023] Figure 1 is a perspective view of a monopile transportation vessel with a monopile handling mechanism according to some examples;

[0024] Figure 2 is a perspective view of a first monopile handling mechanism of the monopile handling mechanism on the monopile transportation vessel according to some examples;

[0025] Figure 3 is a perspective view of a second monopile handling mechanism of the monopile handling mechanism on the monopile transportation vessel according to some examples;

[0026] Figure 4a is a plan schematic view of an offshore installation vessel with the monopile gripper in a retracted position according to some examples;

[0027] Figure 4b is a plan schematic view of an offshore installation vessel with the monopile gripper in an extended position over a cut-out of the hull of the offshore installation vessel according to some examples;

[0028] Figure 5 is a perspective view of an offshore installation vessel with the monopile gripper in an extended position over a cut-out of the hull of the offshore installation vessel according to some examples;

[0029] Figure 6 is a perspective view of the monopile transportation vessel approaching the offshore installation vessel before docking according to some examples;

[0030] Figure 7 is a side view of the monopile transportation vessel approaching the offshore installation vessel before docking with the monopile inclined by the monopile handling equipment according to some examples;

[0031] Figure 8 is a side view of the monopile transportation vessel underneath the cutout of the offshore installation vessel before docking with the monopile inclined by the monopile handling equipment according to some examples;

[0032] Figure 9 is a side view of the monopile transportation vessel docked with offshore installation vessel with a crane lifting the monopile according to some examples;

[0033] Figure 10 is a side view of the monopile transportation vessel secured by the push down stabilising mechanism of offshore installation vessel according to some examples; Figure 11 is a side view of the monopile transportation vessel docked with the offshore installation vessel with the monopile vertical according to some examples;

[0034] Figure 12 is a side view of the monopile transportation vessel docked with the offshore installation vessel with the monopile lifted clear from the monopile transportation vessel according to some examples;

[0035] Figure 13 is a perspective view of the monopile transportation vessel undocked with offshore installation vessel with a crane lifting the monopile and the push down stabilising mechanism lifted off the monopile transportation vessel according to some examples;

[0036] Figure 14 is a perspective view of the offshore installation vessel with the monopile engaged by the monopile gripper ready to be driven into the seafloor according to some examples;

[0037] Figure 15 is a schematic representation of the monopile transportation vessel according to some examples; and

[0038] Figure 16 is a schematic representation of the offshore installation vessel.

[0039] Detailed Description

[0040] The detailed description set forth below provides information and examples of the disclosed technology with sufficient detail to enable those skilled in the art to practise the disclosure.

[0041] Figure 1 illustrates an exemplary embodiment of the offshore installation system 100. The offshore installation system 100 includes a monopile transportation vessel 102, which is specifically designed and configured to transport a monopile 110 in a horizontal position. The monopile transportation vessel 102 is a specialised marine vessel that is capable of carrying heavy loads, such as the monopile 110 or other elongate objects, over long distances in various sea conditions. The monopile transportation vessel 102 is equipped with a monopile handling mechanism 132, which is mounted on the vessel and is configured to secure the monopile 110 during transportation. The monopile transportation vessel 102 is also equipped with various other components and systems to facilitate the transportation and handling of the monopile 110, as will be described in more detail below. In one example, the monopile transportation vessel 102 is a self-propelled vessel that is capable of navigating in open seas. The monopile transportation vessel 102 includes a hull that is designed to withstand the forces exerted by waves, wind, and currents. The monopile transportation vessel 102 also includes a vessel deck 202, which provides a platform for mounting and operating various components and systems of the monopile transportation vessel 102, including the monopile handling mechanism 132.

[0042] In some implementations as shown in the Figures, the monopile transportation vessel 102 is a non-self-propelled barge 108 that is moved by a tug 106. The tug 106 is a powerful, manoeuvrable vessel that is arranged to push or pull other vessels, such as the barge 108. The tug 106 includes a propulsion system that allows the tug 106 to generate a large amount of thrust, which is used to move the barge 108. The tug 106 also includes a navigation system that allows the tug 106 to navigate accurately and efficiently to a desired location, such as an offshore installation site.

[0043] The tug 106 may be connected to the barge 108 by a towline, which allows the tug 106 to pull the barge 108. Alternatively, as shown in Figure 1 , the tug 106 may be connected to the barge 108 in a pusher configuration, in which the tug 106 pushes the barge 108 from behind. The tug 106 and the barge 108 may be configured to operate as an integrated unit, in which the tug 106 and the barge 108 move together as a single entity.

[0044] The monopile transportation vessel 102 alternatively also equipped with a propulsion system (not shown) that allows the monopile transportation vessel 102 to move in various directions and at various speeds. The propulsion system may include one or more engines, propellers, and rudders. The monopile transportation vessel 102 may also include a navigation system that allows the monopile transportation vessel 102 to navigate accurately and efficiently to a desired location, such as an offshore installation site. In this example, the monopile transportation vessel 102 is a powered barge 108 and the tug 106 is not required.

[0045] In some configurations, the monopile transportation vessel 102 is a barge 108 as shown in Figure 1. The barge 108 is a flat-bottomed vessel that is arranged to carry heavy loads, such as the monopile 110, on a vessel deck 202. The vessel deck 202 comprises a large, flat deck area that provides a stable platform for mounting and operating various components and systems of the monopile transportation vessel 102, including the monopile handling mechanism 132.

[0046] The monopile handling mechanism 132 is a specialised system that is mounted on the monopile transportation vessel 102 and is configured to secure the monopile 110 during transportation and to move the monopile 110 to an inclined position when the is near the offshore installation site. The monopile handling mechanism 132 includes various components and systems that work together to handle the monopile 110 in a safe and efficient manner.

[0047] In one example, the monopile handling mechanism 132 includes a first monopile handling mechanism 136 and a second monopile handling mechanism 134. The first monopile handling mechanism 136 is configured to engage a monopile lower portion 112 of the monopile 110, while the second monopile handling mechanism 134 is configured to engage a monopile upper portion 114 of the monopile 110. The first and second monopile handling mechanisms 136, 134 work together to move the monopile 110 from a horizontal position to an inclined position.

[0048] The monopile handling mechanism 132 may also include various other components and systems, such as a lashing mechanism 138 for securing the monopile 110 during transport, a skidding sea fastening support 140 for securely fastening the second monopile handling mechanism 134 to the vessel deck 202 when the monopile 110 is in the horizontal position, and a hydraulic control system 142 for controlling and managing the hydraulic components of the monopile handling mechanism 132.

[0049] The first monopile handling mechanism 136 is a specialised system that is configured to engage the monopile lower portion 112 of the monopile 110. The first monopile handling mechanism 136 includes various components and systems that work together to secure the monopile lower portion 112 of the monopile 110 and to move the monopile lower portion 112 as the monopile 110 moves from a horizontal position to an inclined position. In one implementation, the first monopile handling mechanism 136 includes an upending pivoting frame 144 that is configured to engage the monopile lower portion 112 of the monopile 110.

[0050] The first monopile handling mechanism 136 may also include a skidding sled 154 that is configured to move along a skidding axis 156. The skidding sled 154 includes various components, such as skid rails 162 that are mounted on the vessel deck 202, skidding feet 160 that engage the skid rails 162, and skidding actuators 166 that cause movement of the skidding sled 154 along the skid rails 162. The skidding sled 154 is configured to move the upending pivoting frame 144 and the engaged monopile 110 along the skidding axis 156 as the monopile 110 moves from a horizontal position to an inclined position.

[0051] In one example, the first monopile handling mechanism 136 is moveable between a first skid position and a second skid position. The first skid position is the position of the first monopile handling mechanism 136 on the skid rails 162 when the monopile transportation vessel 102 is transporting the monopile 110 in a horizontal position. In the first skid position, the first monopile handling mechanism 136 is remote from the second monopile handling mechanism 134. This configuration allows the monopile 110 to be securely held in a horizontal position during transportation. Figures 2 and 6 show the first monopile handling mechanism 136 in the first skid position.

[0052] In some implementations, the first monopile handling mechanism 136 is moveable to a second skid position. The second skid position is the position of the first monopile handling mechanism 136 on the skid rails 162 when the monopile transportation vessel 102 is upending the monopile 110. In the second skid position, the first monopile handling mechanism 136 is next to the second monopile handling mechanism 134. This configuration allows the monopile 110 to be moved from a horizontal position to an inclined position. Figures 10 to 14 show the first monopile handling mechanism 136 in the second skid position.

[0053] The second monopile handling mechanism 134 is a specialised system that is configured to engage the monopile upper portion 114. The monopile upper portion 114 can be in the middle of the monopile 110 or at an upper end of the monopile 110. The monopile upper portion 114 is above the monopile lower portion 112 when the monopile 110 is in the vertical orientation. Alternatively, the second monopile handling mechanism 134 engages a portion of the monopile 110 remote from the monopile lower portion 112.

[0054] In one implementation, the second monopile handling mechanism 134 includes a climbing cradle 182 that is configured to engage the monopile upper portion 114 of the monopile 110. The climbing cradle 182 includes various components, such as a cradle pivot axis 180 about which the climbing cradle 182 pivots, and a cradle pivot actuator 184 that is configured to rotate the climbing cradle 182 about the cradle pivot axis 180. The second monopile handling mechanism 134 is moveable between a first cradle position and a second cradle position. The first cradle position is the position of the climbing cradle 182 on the cradle supports 194 when the monopile transportation vessel 102 is transporting the monopile 110 in a horizontal position. The second cradle position is the position of the climbing cradle 182 on the cradle supports 194 when the monopile transportation vessel 102 is upending the monopile 110.

[0055] In one example, the second monopile handling mechanism 134 is moveable between a first cradle position and a second cradle position. The first cradle position is the position of the climbing cradle 182 on the cradle supports 194 when the monopile transportation vessel 102 is transporting the monopile 110 in a horizontal position. In the first cradle position, the climbing cradle 182 is adjacent to the vessel deck 202. This configuration allows the monopile 110 to be securely held in a horizontal position during transportation.

[0056] In some implementations, the second monopile handling mechanism 134 is moveable to a second cradle position. The second cradle position is the position of the climbing cradle 182 on the cradle supports 194 when the monopile transportation vessel 102 is upending the monopile 110. In the second cradle position, the climbing cradle 182 is remote from the vessel deck 202. This configuration allows the monopile 110 to be moved from a horizontal position to an inclined position.

[0057] Figure 2 provides a detailed perspective view of the first monopile handling mechanism 136, specifically focusing on the upending pivoting frame 144 and its associated components. The upending pivoting frame 144 is a pivotal component of the first monopile handling mechanism 136, designed to engage the monopile lower portion 112 of the monopile 110 and facilitate its movement from a horizontal to an inclined position.

[0058] The upending pivoting frame 144 is a robust structure designed to securely engage and handle the monopile 110 and pivot about the upending pivot axis 146 as the first monopile handling mechanism 136 as the monopile 110 is moved into the inclined position. The monopile 110 is inclined when the second monopile handling mechanism 134 moves between the first cradle position to the second cradle position. The upending pivoting frame 144 is pivotally mounted in a skidding sled 154 as discussed in more detail below.

[0059] The frame base strut 224 is a component of the upending pivoting frame 144, which is arranged to engage the monopile base 222 of the monopile 110. In some implementations, the frame base strut 224 is designed to accommodate the specific shape and size of the monopile base 222, ensuring a secure and stable engagement. The frame base strut 224 may be made from a robust material, such as steel or another suitable metal, to withstand the weight and forces exerted by the monopile 110 during the handling process.

[0060] The upending pivot axis 146 is a pivotal point around which the upending pivoting frame 144 rotates with respect to the skidding sled 154. The upending pivot axis 146 is positioned in such a way that it allows the upending pivoting frame 144 to pivot from a horizontal position, where the monopile 110 is in a horizontal position, to an inclined position, where the monopile 110 is in an inclined position. The upending pivot axis 146 may be a fixed point or a movable point, depending on the specific design and configuration of the upending pivoting frame 144. As shown in the Figures, the upending pivot axis 146 is fixed with respect to the upending pivoting frame 144 and the skidding sled 154.

[0061] The frame engagement surface 148 is a part of the upending pivoting frame 144 that is designed to engage the surface of the monopile 110. The frame engagement surface 148 is typically curved to match the curved surface of the monopile 110, ensuring a secure and stable engagement. In some implementations, the frame engagement surface 148 may have a semi-circular shape to accommodate the cylindrical shape of the monopile 110. The frame engagement surface 148 may optionally be made from a material that provides a good grip on the monopile 110, such as rubber or another suitable material. The frame engagement surface 148 may also include additional features, such as upending pivoting beams 150 and upending pivoting saddles 152, to accommodate different diameters of the monopile 110 and to facilitate the movement of the monopile 110 from a horizontal to an inclined position.

[0062] The upending pivoting beams 150 are components of the upending pivoting frame 144 that are pivotally mounted on the frame engagement surface 148. The upending pivoting beams 150 are designed to move in order to accommodate different diameter monopiles 110.

[0063] The upending pivoting saddles 152 are components of the upending pivoting frame 144 that are pivotally mounted on each end of the upending pivoting beams 150. The upending pivoting saddles 152 are designed to pivot about an axis in a direction parallel with the skidding axis 156. This means that the upending pivoting saddles 152 accommodate different diameters of the monopile 110. This movement is facilitated by the upending pivot axis 146, around which the upending pivoting saddles 152 pivot. The upending pivoting saddles 152 are designed to securely engage the monopile 110, providing additional stability and control during the handling process.

[0064] The upending pivot pins 170 are components of the upending pivoting frame 144 that are aligned with the upending pivot axis 146. The upending pivot pins 170 are designed to engage the upending pivoting frame 144 and the skidding frame 158, providing a pivot connection between these components.

[0065] The upending pivot actuators 172 are components of the upending pivoting frame 144 that are connected between the upending pivoting frame 144 and the skidding frame 158. The upending pivot actuators 172 are designed to rotate the upending pivoting frame 144 about the upending pivot axis 146, facilitating the movement of the monopile 110 from a horizontal to an inclined position. The upending pivot actuators 172 may be hydraulic cylinders, electro-mechanical actuators, rack and pinion systems, or other suitable types of actuators. The upending pivot actuators 172 are controlled by the hydraulic control system 142, which manages the operation of the hydraulic components of the monopile handling mechanism 132.

[0066] The skidding sled 154 is a component of the first monopile handling mechanism 136 that is designed to move along a skidding axis 156. The skidding sled 154 is configured to move the upending pivoting frame 144 and the engaged monopile 110 along the skidding axis 156 as the monopile 110 moves from a horizontal position to an inclined position. In this way, the skidding sled 154 moves the monopile lower portion 112 from the first skidding position to the second skidding position.

[0067] The skidding sled 154 is a robust structure that is designed to withstand the forces exerted by the monopile 110 and the upending pivoting frame 144 during the handling process. The skidding sled 154 may be made from a robust material, such as steel or another suitable metal, to withstand the weight and forces exerted by the monopile 110 and the upending pivoting frame 144.

[0068] The skid rails 162 are mounted on the vessel deck 202 and define the path that the skidding sled 154 moves between the first skidding position and the second skidding position. As shown in Figure 1 , the skid rails 162 are aligned with the skidding axis 156 and are designed to guide the movement of the skidding sled 154 along the skidding axis 156.

[0069] The skid rails 162 may include skidding steps holes 168 that are configured to receive a frame locking pin 164. The frame locking pin 164 is configured to engage the skidding steps holes 168 to lock the skidding sled 154 with respect to the skid rails 162. This configuration allows the skidding sled 154 to be securely held in a specific position along the skidding axis 156.

[0070] The skidding axis 156 is a directional reference that defines the direction of movement of the skidding sled 154 along the skid rails 162. The skidding axis 156 is typically aligned with the longitudinal axis of the monopile transportation vessel 102, allowing the monopile 110 to be moved from a horizontal position at one end of the monopile transportation vessel 102 to an inclined position at the other end of the monopile transportation vessel 102.

[0071] The skidding frame 158 is a component of the skidding sled 154 that is designed to engage the skid rails 162 and move along the skidding axis 156. The skidding frame 158 includes various components, such as skidding feet 160 that are fixed to the bottom of the skidding frame 158 and engage the skid rails 162, and a frame locking pin 164 that is configured to engage skidding steps holes 168 in the skid rails 162 to lock the skidding frame 158 with respect to the skid rails 162.

[0072] In one example, the skidding frame 158 comprises an A-frame structure on either side of the upending pivoting frame 144. This A-frame structure provides stability and rigidity to the skidding frame 158, allowing it to withstand the forces exerted by the monopile 110 and the upending pivoting frame 144 during the handling process.

[0073] The skidding feet 160 are components of the skidding frame 158 that are fixed to the bottom of the skidding frame 158 and are designed to engage the skid rails 162. The skidding feet 160 provide a point of contact between the skidding frame 158 and the skid rails 162, allowing the skidding frame 158 to move along the skidding axis 156.

[0074] In some implementations, the skidding feet 160 are designed to engage the skid rails 162 in a secure and stable manner. For example, the skidding feet 160 may include features, such as grooves or ridges, that interlock with corresponding features on the skid rails 162. This interlocking engagement helps to prevent the skidding feet 160 from slipping or sliding on the skid rails 162 during the handling process.

[0075] The frame locking pin 164 is a component of the skidding frame 158 that is configured to engage skidding steps holes 168 in the skid rails 162 to lock the skidding frame 158 with respect to the skid rails 162. The frame locking pin 164 provides a secure and stable connection between the skidding frame 158 and the skid rails 162, preventing the skidding frame 158 from moving along the skidding axis 156 when the frame locking pin 164 is engaged. The frame locking pin 164 is inserted through the skidding feet 160 into the skidding steps holes 168. One or more of the skidding feet 160 can receive a frame locking pin 164. For example, as shown in Figure 2, two of the skidding feet 160 are locked in position on the skid rails 162 each with a frame locking pin 164.

[0076] In one example, the frame locking pin 164 is a robust pin that is designed to withstand the forces exerted by the skidding frame 158 and the upending pivoting frame 144. The frame locking pin 164 may be manually or automatically engaged and disengaged, depending on the specific design and configuration of the skidding frame 158 and the skid rails 162.

[0077] The skidding actuators 166 are components of the skidding sled 154 that are designed to cause movement of the skidding frame 158 along the skid rails 162. The skidding actuators 166 generate a force that is applied to the skidding frame 158, causing the skidding frame 158 to move along the skidding axis 156. The skidding actuators 166 may be hydraulic cylinders, electro-mechanical actuators, rack and pinion systems, or other suitable types of actuators.

[0078] In one example, the skidding actuators 166 are controlled by the hydraulic control system 142, which manages the operation of the hydraulic components of the monopile handling mechanism 132. The hydraulic control system 142 may include various components, such as a hydraulic reservoir, a hydraulic pump, hydraulic hoses, and a controller, to control and manage the operation of the skidding actuators 166. The hydraulic control system 142 may be configured to control the speed, direction, and force of the skidding actuators 166, allowing the skidding frame 158 to be moved along the skidding axis 156 in a controlled and precise manner.

[0079] As mentioned above, the skidding steps holes 168 are features of the skid rails 162 that are designed to receive the frame locking pin 164. The skidding steps holes 168 are positioned at specific locations along the skid rails 162, allowing the skidding frame 158 to be locked in specific positions along the skidding axis 156. The skidding steps holes 168 may be evenly spaced along the skid rails 162, or they may be positioned at specific locations to accommodate specific positions of the monopile 110 and the upending pivoting frame 144. In one example, the skidding steps holes 168 are circular holes that are sized to receive the frame locking pin 164. The skidding steps holes 168 may be lined with a durable material, such as metal or plastic, to prevent wear and tear from the repeated engagement and disengagement of the frame locking pin 164. The skidding steps holes 168 may also include features, such as chamfers or bevels, to facilitate the engagement and disengagement of the frame locking pin 164.

[0080] The lashing mechanism 138 is a component of the monopile handling mechanism 132 that is designed to secure the monopile 110 to the upending pivoting frame 144 during transport. The lashing mechanism 138 includes various components, such as lashing slings 174 and lashing trunnions 176, that work together to securely hold the monopile 110 in place.

[0081] In one example, the lashing mechanism 138 is mounted to the first monopile handling mechanism 136. This positioning allows the lashing mechanism 138 to secure the monopile 110 e.g. the monopile lower portion 112 to the upending pivoting frame 144, preventing the monopile 110 from moving or shifting during transportation. The lashing mechanism 138 may be manually or automatically engaged and disengaged, depending on the specific design and configuration of the lashing mechanism 138.

[0082] The lashing slings 174 are components of the lashing mechanism 138 that are designed to wrap around the surface of the monopile 110 at the monopile lower portion 112 and connect to the lashing trunnions 176 at each end of the lashing slings 174. The lashing slings 174 provide a secure and stable connection between the monopile 110 and the upending pivoting frame 144, preventing the monopile 110 from moving or shifting during transportation.

[0083] In one example, the lashing slings 174 are made from a robust material, such as steel or another suitable metal, to withstand the weight and forces exerted by the monopile 110. The lashing slings 174 may be adjustable in length, allowing the lashing slings 174 to accommodate different sizes and shapes of the monopile 110. The lashing slings 174 may also include features, such as hooks or loops, to facilitate the engagement and disengagement of the lashing slings 174 with the lashing trunnions 176. As shown in Figure 2 there are two lashing slings 174 for securing the monopile lower portion 112. However, there can be any suitable number of lashing slings 174 as required.

[0084] The lashing trunnions 176 are components of the lashing mechanism 138 that are designed to engage with an end loop in the lashing slings 174. The lashing trunnions 176 provide a secure and stable connection point for the lashing slings 174, allowing the lashing slings 174 to securely hold the monopile 110 in place.

[0085] In one example, the lashing trunnions 176 are fixed to either side of the upending pivoting frame 144. This positioning allows the lashing trunnions 176 to provide a secure and stable connection point for the lashing slings 174, preventing the monopile 110 from moving or shifting during transportation. The lashing trunnions 176 may be made from a robust material, such as steel or another suitable metal, to withstand the weight and forces exerted by the monopile 110 and the lashing slings 174. The lashing trunnions 176 may also include features, such as hooks or loops, to facilitate the engagement and disengagement of the lashing trunnions 176 with the lashing slings 174.

[0086] The end loop is a feature of the lashing slings 174 that is designed to engage with the lashing trunnions 176. The end loop provides a secure and stable connection point for the lashing slings 174, allowing the lashing slings 174 to securely hold the monopile 110 in place.

[0087] In one example, the end loop is a circular loop that is formed at each end of the lashing slings 174. The end loop is sized to fit over the lashing trunnions 176, providing a secure and stable connection between the lashing slings 174 and the lashing trunnions 176. The end loop may be made from the same material as the lashing slings 174, such as steel or another suitable metal, to withstand the weight and forces exerted by the monopile 110. The end loop may also include features, such as a locking mechanism, to prevent the end loop from accidentally disengaging from the lashing trunnions 176.

[0088] In some implementations, the lashing tensioning system 178 is part of the lashing mechanism 138 and is arranged to apply a tension force to the lashing slings 174 around the monopile 110 surface to the upending pivoting frame 144. The lashing tensioning system 178 can be hydraulic tensioning cylinders, turnbuckles, ratchet straps, mechanical winches, pneumatic tensioning systems, chain binders, or tensioning bolts.

[0089] Figure 3 provides a detailed perspective view of the second monopile handling mechanism 134, specifically focusing on the climbing cradle 182 and its associated components. The climbing cradle 182 is a pivotal component of the second monopile handling mechanism 134, designed to engage the monopile upper portion 114 of the monopile 110 and facilitate its movement from a horizontal to an inclined position.

[0090] The climbing cradle 182 is a robust structure designed to securely engage and handle the monopile upper portion 114 of the monopile 110. In one example, the climbing cradle 182 includes a cradle pivot axis 180, cradle pivot actuators 184, and a cradle engagement surface 188. The cradle pivot axis 180 is a pivotal point around which the climbing cradle 182 rotates, facilitating the movement of the monopile 110 from a horizontal to an inclined position. The cradle pivot actuators 184 are connected between the climbing cradle 182 and the cradle brackets 196 and are configured to rotate the climbing cradle 182 about the cradle pivot axis 180. The cradle engagement surface 188 is designed to engage the surface of the monopile 110, providing additional stability and control during the handling process.

[0091] The cradle pivot pins (not shown) are components of the climbing cradle 182 that are aligned with the cradle pivot axis 180. The cradle pivot pins provide a pivot connection between the climbing cradle 182 and the cradle brackets 196, allowing the climbing cradle 182 to pivot about the cradle pivot axis 180.

[0092] The cradle supports 194 are components of the second monopile handling mechanism 134 that are designed to support the climbing cradle 182. The cradle supports 194 are upright structures that are mounted to the vessel deck 202 and are positioned on either side of the skid rails 162. The cradle supports 194 provide a stable and secure platform for the climbing cradle 182, allowing the climbing cradle 182 to move vertically along the cradle supports 194 as the monopile 110 moves from a horizontal position to an inclined position. In one example, the cradle supports 194 are made from a robust material, such as steel or another suitable metal, to withstand the weight and forces exerted by the climbing cradle 182 and the monopile 110. The cradle supports 194 may include various features, such as slots or holes, to accommodate the movement of the climbing cradle 182 and the cradle brackets 196 along the cradle supports 194.

[0093] The cradle braces 198 are optional components of the second monopile handling mechanism 134 that are designed to further secure the cradle supports 194 to the vessel deck 202. The cradle braces 198 are either aligned parallel with the skidding axis 156 or perpendicular with the skidding axis 156, providing additional stability and rigidity to the cradle supports 194 in multiple directions.

[0094] In one example, the cradle braces 198 are connected between the cradle supports 194 and the vessel deck 202. This connection allows the cradle braces 198 to transfer the weight and forces exerted by the climbing cradle 182 and the monopile 110 to the vessel deck 202, preventing the cradle supports 194 from moving or shifting during the handling process. The cradle braces 198 may be made from a robust material, such as steel or another suitable metal, to withstand these forces.

[0095] The cradle pivot actuators 184 are components of the climbing cradle 182 that are connected between the climbing cradle 182 and the cradle brackets 196. The cradle pivot actuators 184 are designed to rotate the climbing cradle 182 about the cradle pivot axis 180, facilitating the movement of the monopile 110 from a horizontal position to an inclined position.

[0096] In one example, the cradle pivot actuators 184 may be hydraulic cylinders, electromechanical actuators, pneumatic actuators, or rack and pinion systems. These types of actuators are capable of generating a large amount of force, allowing the cradle pivot actuators 184 to rotate the heavy climbing cradle 182 and the monopile 110. The cradle pivot actuators 184 are controlled by the hydraulic control system 142, which manages the operation of the hydraulic components of the monopile handling mechanism 132. The cradle pivot actuators 184 are positioned in such a way that they can apply a rotational force to the climbing cradle 182 about the cradle pivot axis 180. This rotational force allows the climbing cradle 182 to pivot from a horizontal position, where the monopile 110 is in a horizontal position, to an inclined position, where the monopile 110 is in an inclined position. The cradle pivot actuators 184 may be adjustable, allowing the force exerted by the cradle pivot actuators 184 to be adjusted to accommodate different weights and sizes of the monopile 110.

[0097] The cradle pivot axis 180 is a pivotal point around which the climbing cradle 182 rotates. The cradle pivot axis 180 is positioned in such a way that it allows the climbing cradle 182 to pivot from a horizontal position, where the monopile 110 is in a horizontal position, to an inclined position, where the monopile 110 is in an inclined position. The cradle pivot axis 180 is perpendicular to the skidding axis 156. The cradle pivot axis 180 is parallel to the upending pivot axis 146.

[0098] The cradle actuators 186 are components of the climbing cradle 182 that are coupled between the cradle brackets 196 and the cradle supports 194. The cradle actuators 186 are designed to move the climbing cradle 182 vertically along the cradle supports 194, facilitating the movement of the monopile 110 from a horizontal position to an inclined position.

[0099] In one example, the cradle actuators 186 may be hydraulic cylinders, electromechanical actuators, rack and pinion systems, or hydraulic telescopic rams. These types of actuators are capable of generating a large amount of force, allowing the cradle actuators 186 to move the heavy climbing cradle 182 and the monopile 110. The cradle actuators 186 are controlled by the hydraulic control system 142, which manages the operation of the hydraulic components of the monopile handling mechanism 132.

[0100] The cradle actuators 186 are positioned in such a way that they can apply a vertical force to the climbing cradle 182. The force is in a direction away from the vessel deck 202. This vertical force allows the climbing cradle 182 to move vertically along the cradle supports 194, facilitating the movement of the monopile 110 from a horizontal position to an inclined position. The cradle actuators 186 may be adjustable, allowing the force exerted by the cradle actuators 186 to be adjusted to accommodate different weights and sizes of the monopile 110.

[0101] Similar to the frame engagement surface 148, the climbing cradle 182 comprises a cradle engagement surface 188. The cradle engagement surface 188 is designed to engage the surface of the monopile 110. The cradle engagement surface 188 is typically curved to match the curved surface of the monopile 110, ensuring a secure and stable engagement. In some implementations, the cradle engagement surface 188 may have a semi-circular shape to accommodate the cylindrical shape of the monopile 110. The cradle engagement surface 188 may optionally be made from a material that provides a good grip on the monopile 110, such as rubber or another suitable material.

[0102] In order to accommodate different diameters, the climbing cradle 182 optionally comprises a similar arrangement to the first monopile handling mechanism 136. Specifically, the cradle engagement surface 188 may also include additional features, such as cradle pivoting beams 190 and cradle pivoting saddles 192, to accommodate different diameters of the monopile 110. the cradle pivoting beams 190 are components of the climbing cradle 182 that are pivotally mounted on the cradle engagement surface 188. The cradle pivoting beams 190 are designed to move to accommodate different diameters of the monopile 110 and different diameter monopile upper portions 114 which may have narrowing or tapering sections.

[0103] The cradle pivoting saddles 192 are components of the climbing cradle 182 that are pivotally mounted on each end of the cradle pivoting beams 190. The cradle pivoting saddles 192 are designed to pivot about an axis parallel with the skidding axis 156, accommodating different diameters of the monopile 110. The cradle pivoting saddles 192 are designed to securely engage the monopile 110, providing additional stability and control during the handling process.

[0104] The cradle brackets 196 are components of the second monopile handling mechanism 134 that are moveable on the cradle supports 194. The cradle brackets 196 provide a secure and stable connection point for the climbing cradle 182, allowing the climbing cradle 182 to move vertically along the cradle supports 194. The cradle brackets 196 may be made from a robust material, such as steel or another suitable metal, to withstand the weight and forces exerted by the climbing cradle 182 and the monopile 110.

[0105] In one example, the cradle brackets 196 are designed to engage with corresponding slots or holes in the cradle supports 194. This engagement allows the cradle brackets 196 to securely hold the climbing cradle 182 in place, preventing the climbing cradle 182 from moving or shifting during the handling process. The cradle brackets 196 may be manually or automatically engaged and disengaged, depending on the specific design and configuration of the cradle brackets 196 and the cradle supports 194.

[0106] The cradle locking pin 200 is a component of the cradle brackets 196 that is configured to engage cradle support holes (not shown) in the cradle supports 194 to lock the second monopile handling mechanism 134 with respect to the cradle supports 194. The cradle locking pin 200 provides a secure and stable connection between the cradle brackets 196 and the cradle supports 194, preventing the cradle brackets 196 from moving along the cradle supports 194 when the cradle locking pin 200 is engaged.

[0107] In one example, the cradle locking pin 200 is a robust pin that is designed to withstand the forces exerted by the cradle brackets 196 and the climbing cradle 182. The cradle locking pin 200 may be made from a robust material, such as steel or another suitable metal, to withstand these forces. The cradle locking pin 200 may be manually or automatically engaged and disengaged, depending on the specific design and configuration of the cradle brackets 196 and the cradle supports 194.

[0108] As shown in Figure 3, the monopile transportation vessel 102 optionally comprises a skidding sea fastening support 140. The skidding sea fastening support 140 is configured to securely fasten the second monopile handling mechanism 134 to the vessel deck 202 when the monopile 110 is in the horizontal position. The skidding sea fastening support 140 provides a secure and stable connection between the second monopile handling mechanism 134 and the vessel deck 202, preventing the second monopile handling mechanism 134 from moving or shifting during transportation. In one example, the skidding sea fastening support 140 includes a support connector 220 that is designed to connect to the climbing cradle 182. The support connector 220 may be a quick-release pin, a magnetic lock, a spring-loaded latch, a rotary clamp, or another suitable type of connector. The support connector 220 provides a secure connection between the skidding sea fastening support 140 and the climbing cradle 182, preventing the climbing cradle 182 from moving or shifting during transportation. The support connector 220 is operatively coupled with one or more support actuators 212. In some examples, the support actuators 212 are part of the monopile handling mechanism 132 and are configured to move the skidding sea fastening support 140 between the engaged and retracted positions. The support actuators 212 can be hydraulic telescopic rods, electro-hydraulic lifters, rack and pinion systems, or threaded rod actuators with motors. The support actuators 212 are designed to withstand the forces exerted during operation and to provide precise control over the movement of the skidding sea fastening support 140.

[0109] The skidding sea fastening support 140 is mounted on the vessel deck 202 and is moveable between an engage position whereby the support connector 220 engages the climbing cradle 182 and a retracted position whereby the support connected 220 is disengaged.

[0110] Reference will now be made to Figure 4a, which illustrates an exemplary embodiment of the offshore installation vessel 104. The offshore installation vessel 104 is a specialised marine vessel that is designed and configured to handle and install the monopile 110 at an offshore installation site. In some examples, the offshore installation vessel 104 is a jack-up vessel. The offshore installation vessel 104 includes various components and systems, such as a hull 122, moveable legs 126, a push down stabilising mechanism 130, and a monopile gripper 128, which work together to handle and install the monopile 110 in a safe and efficient manner.

[0111] In one example, the offshore installation vessel 104 is a self-propelled vessel that is capable of navigating in open seas. The offshore installation vessel 104 includes a hull 122 that is designed to withstand the forces exerted by waves, wind, and currents. The offshore installation vessel 104 also includes an offshore installation vessel deck 120, which provides a platform for mounting and operating various components and systems of the offshore installation vessel 104, including the push down stabilising mechanism 130 and the monopile gripper 128.

[0112] The offshore installation vessel 104 is also equipped with a propulsion system that allows the offshore installation vessel 104 to move in various directions and at various speeds. The propulsion system may include one or more engines, propellers, and rudders. The offshore installation vessel 104 may also include a navigation system that allows the offshore installation vessel 104 to navigate accurately and efficiently to a desired location, such as an offshore installation site.

[0113] The offshore installation vessel deck 120 of the offshore installation vessel 104 provides a platform for mounting and operating various components and systems of the offshore installation vessel 104, including the push down stabilising mechanism 130 and the monopile gripper 128. The offshore installation vessel deck 120 is designed to withstand the forces exerted by the monopile 110 and the various components and systems of the offshore installation vessel 104, as well as the forces exerted by the sea and the wind.

[0114] In some implementations, the offshore installation vessel deck 120 includes a cut-out 124 that is configured to align with the monopile handling mechanism 132 when the monopile transportation vessel 102 is positioned underneath the hull 122 and when the monopile 110 is in an inclined position. The cut-out 124 provides a space through which the monopile 110 can be moved from the monopile transportation vessel 102 to the offshore installation vessel 104.

[0115] The offshore installation vessel deck 120 may also include various other features, such as mounting points for the push down stabilising mechanism 130 and the monopile gripper 128, and safety features, such as guardrails, non-slip surfaces, and safety markings, to ensure the safety of the personnel operating on the offshore installation vessel deck 120.

[0116] The offshore installation vessel deck 120 may comprise a crane 214. The crane 214 is mounted on the offshore installation vessel deck 120 and is used to lift and position the monopile 110 during upending and installation with cable 206. The crane 214 can be a telescopic crane, a lattice boom crane, a knuckle boom crane, or any other type of crane suitable for lifting and positioning heavy loads. The crane 214 can include features such as a winch, a hook, a boom, and a control system to allow for precise control over the lifting and positioning of the monopile 110.

[0117] The cable 206 can be connected to a winch or other mechanical device on the offshore installation vessel 104 to control the movement of the monopile 110. The cable 206 is connected to the monopile 110 using known methods and is not described in any further detail.

[0118] The cut-out 124 is a feature of the hull 122 of the offshore installation vessel 104 that is designed to align with the monopile handling mechanism 132 when the monopile transportation vessel 102 is positioned underneath the hull 122. When the monopile transportation vessel 102 is positioned underneath the hull 122, the monopile 110 may be in an inclined position. The cut-out 124 provides a space through which the monopile 110 can be moved from the monopile transportation vessel 102 to the offshore installation vessel 104.

[0119] In one example, the cut-out 124 is a large opening in the hull 122 that is sized and shaped to accommodate the monopile 110 and the monopile handling mechanism 132. The cut-out 124 may be positioned at a specific location on the hull 122, such as at the centre of the hull 122, to provide a balanced and stable platform for the monopile 110 and the monopile handling mechanism 132. The cut-out 124 may be lined with a durable material, such as metal or plastic, to prevent wear and tear from the repeated movement of the monopile 110 and the monopile handling mechanism 132 through the cut-out 124. The cut-out 124 can be a segment removed from the edge of the hull 122 which results in a “U-shaped” hull 122. Alternatively, the cut-out 124 can be positioned in the centre of the hull 122 in which case the hull 122 comprises a central moon-pool (not shown).

[0120] The moveable legs 126 are components of the offshore installation vessel 104 that are designed to engage the seafloor 118 and raise the hull 122 out of the water when extended. The offshore installation vessel 104 is shown in Figures 7 to 12 with the hull 122 raised out of the water. The water surface 208 is depicted as a flat plane in Figure 7. However, it should be understood that the water surface 208 can vary due to waves, tides, and other environmental factors. The offshore installation system 100 is designed to operate in various sea conditions, and the components of the system, such as the monopile transportation vessel 102, the offshore installation vessel 104, and the monopile 110, are designed to withstand the forces exerted by the water and the waves. The moveable legs 126 provide stability to the offshore installation vessel 104, allowing the offshore installation vessel 104 to remain stationary and stable during the handling and installation of the monopile 110.

[0121] In one example, the moveable legs 126 are long, sturdy structures that are capable of withstanding the weight of the offshore installation vessel 104 and the forces exerted by the sea and the wind.

[0122] The moveable legs 126 are positioned in such a way that they can provide a balanced and stable platform for the offshore installation vessel 104. For example, the moveable legs 126 may be positioned at the corners of the hull 122, providing a wide base of support for the offshore installation vessel 104. The moveable legs 126 may also include features, such as spud cans, foot pads or spikes, to engage the seafloor 118 and prevent the moveable legs 126 from sinking into the seafloor 118.

[0123] The monopile gripper 128 is a component of the offshore installation vessel 104 that is designed to grip and secure the monopile 110 for handling and installation. The monopile gripper 128 provides a secure and stable connection between the monopile 110 and the offshore installation vessel 104, preventing the monopile 110 from moving or shifting during the handling and installation process.

[0124] In one example, the monopile gripper 128 includes various components, such as jaws or clamps, that are designed to engage the surface of the monopile 110. The jaws or clamps of the monopile gripper 128 may be adjustable, allowing the monopile gripper 128 to accommodate different sizes and shapes of the monopile 110. The jaws or clamps of the monopile gripper 128 may also include features, such as teeth or ridges, to provide a good grip on the monopile 110. The monopile gripper 128 is mounted on the offshore installation vessel 104 in such a way that it can move the monopile 110 in various directions. For example, the monopile gripper 128 may be mounted on a crane 214 or a boom that allows the monopile gripper 128 to move the monopile 110 vertically, horizontally, or rotationally. The monopile gripper 128 may be manually or automatically operated, depending on the specific design and configuration of the monopile gripper 128. Alternatively, as shown in the Figures, the monopile gripper 128 is mounted on skids on the offshore installation vessel deck 120 and moveable between a position remote from the cut-out 124 as shown in Figure 4a and a position overhanging the cut-out 124 as shown in Figure 4b. The monopile gripper 128 can be moved over the cut-out 124 when the monopile 110 is in a vertical orientation e.g. as shown in Figures 5 and 14.

[0125] The push down stabilising mechanism 130 is a component of the offshore installation vessel 104 that is designed to apply a downward force on the monopile transportation vessel 102 to increase the buoyancy force on the monopile transportation vessel 102. The push down stabilising mechanism 130 provides additional stability to the monopile transportation vessel 102 and the inclined monopile 110 with respect to the offshore installation vessel 104, preventing the monopile transportation vessel 102 and the inclined monopile 110 from moving or shifting during the handling and installation process. In other words, when the push down stabilising mechanism 130 exerts a force on the monopile transportation vessel 102, the monopile transportation vessel 102 does not move with respect to the offshore installation vessel 104. This means that the upending operation of the monopile 110 can occur on the monopile transportation vessel 102 and not on the offshore installation vessel 104. This reduces the time of the upending process because the monopile 110 does not have to be transferred on to the offshore installation vessel 104 in a horizontal position.

[0126] In one example, the push down stabilising mechanism 130 includes various components, such as push down actuators 216 and push down engagement portions 210. The push down actuators 216 are designed to generate a downward force that is applied to the monopile transportation vessel 102. The push down engagement portions 210 are designed to engage a surface of the monopile transportation vessel 102, such as the vessel deck 202, and apply the downward force generated by the push down actuators 216. The push down stabilising mechanism 130 is mounted on the offshore installation vessel 104 in such a way that it can apply a downward force on the monopile transportation vessel 102 when the monopile transportation vessel 102 is positioned underneath the hull 122 of the offshore installation vessel 104. The push down stabilising mechanism 130 may be manually or automatically operated, depending on the specific design and configuration of the push down stabilising mechanism 130. The push down actuators 216 and push down engagement portions 210 are arranged around the periphery of the cut-out 124 as shown in Figure 5. This means that the push down actuators 216 and push down engagement portions 210 engage around the periphery of the monopile transportation vessel 102. The push down actuators 216 and push down engagement portions 210 are arranged such at the push down actuators 216 and push down engagement portions 210 are positioned on opposite sides of the monopile handling mechanism 132 when the monopile handling mechanism 132 and the monopile transportation vessel 102 is aligned with the cut-out 124.

[0127] The reciprocal deck receiving portion 204 is a feature of the vessel deck 202 of the monopile transportation vessel 102 that is designed to receive and secure the push down engagement portions 210. In some examples the push down engagement portions 210 are feet portions of the push down stabilising mechanism 130. The reciprocal deck receiving portion 204 provides a secure and stable connection between the push down stabilising mechanism 130 and the monopile transportation vessel 102, allowing the push down stabilising mechanism 130 to apply a downward force on the monopile transportation vessel 102.

[0128] In one example, the reciprocal deck receiving portion 204 includes one or more various features, such as deck sockets, recessed slots, interlocking mechanisms, custom- fitted indentations, spring-loaded retention pins, hydraulically actuated locking pins, rotary latches, and threaded engagement bolts, to securely engage the feet portions of the push down stabilising mechanism 130. The reciprocal deck receiving portion 204 may be made from a robust material, such as steel or another suitable metal, to withstand the weight and forces exerted by the push down stabilising mechanism 130. Figure 6 provides a detailed view of the offshore installation system 100 where the monopile transportation vessel 102 approaches the offshore installation vessel 104 with the monopile 110 in a horizontal position.

[0129] The monopile 110 is a large, cylindrical structure that is designed to be installed in the seafloor 118 to support an offshore wind turbine.

[0130] The monopile 110 includes various features, such as a monopile lower portion 112 that is designed to be driven into the seafloor 118 during the installation of the monopile 110, and an monopile upper portion 114 that is designed to engage a transition piece of a wind turbine generator after the installation of the monopile 110. The monopile 110 also includes a monopile surface 116. As discussed above, various components of the monopile handling mechanism 132, such as the upending pivoting frame 144 and the climbing cradle 182 are arranged to engage the monopile surface 116.

[0131] The monopile 110 is transported in a horizontal position on the monopile transportation vessel 102 to the offshore installation site as shown in Figure 6. Once at the site, the monopile 110 is moved to an inclined position by the monopile handling mechanism 132, and then to a vertical position for installation into the seafloor 118. The monopile 110 is then gripped by the monopile gripper 128 and installed into the seafloor 118 by the offshore installation vessel 104.

[0132] Figure 15 illustrates the schematic view of the monopile transportation vessel 102 including the various actuators and a hydraulic control system 142.

[0133] In some examples, the hydraulic control system 142 is part of the monopile transportation vessel 102 and is configured to control and manage the hydraulic components of the monopile handling mechanism 132. The hydraulic control system 142 includes a hydraulic reservoir, a hydraulic pump, hydraulic hoses, and a controller. The hydraulic control system 142 is designed to provide precise control over the hydraulic components and to ensure reliable operation of the monopile handling mechanism 132. For example, the hydraulic control system 142 is configured to control one or more of the cradle pivot actuators 184, the upending pivot actuators 172, the support actuators 212, the cradle actuators 186, and the skidding actuators 166. In some configurations, the hydraulic reservoir is part of the hydraulic control system 142 and is designed to store the hydraulic fluid used by the hydraulic components of the monopile handling mechanism 132. The hydraulic reservoir can be made of a durable and robust material to withstand the pressures exerted during operation. The hydraulic reservoir can also include features such as a fluid level indicator, a temperature gauge, and a pressure relief valve to monitor and control the condition of the hydraulic fluid.

[0134] In some examples, the hydraulic pump is part of the hydraulic control system 142 and is designed to generate the hydraulic pressure required to operate the hydraulic components of the monopile handling mechanism 132. The hydraulic pump can be a gear pump, a piston pump, a vane pump, or any other type of pump suitable for generating hydraulic pressure. The hydraulic pump can be driven by an electric motor, a diesel engine, or any other suitable power source.

[0135] In some implementations, the hydraulic hoses are part of the hydraulic control system 142 and are designed to transport the hydraulic fluid from the hydraulic reservoir to the hydraulic components of the monopile handling mechanism 132. The hydraulic hoses can be made of a flexible and durable material to withstand the pressures and temperatures of the hydraulic fluid. The hydraulic hoses can also include features such as quick-connect fittings, pressure relief valves, and check valves to ensure safe and reliable operation.

[0136] In some configurations, the controller is part of the hydraulic control system 142 and is designed to control the operation of the hydraulic components of the monopile handling mechanism 132. The controller can be a programmable logic controller (PLC), a microcontroller, a computer, or any other suitable control device. The controller can include features such as a user interface, input and output ports, and communication interfaces to allow for monitoring and control of the hydraulic components.

[0137] Figure 16 illustrates a schematic view of the offshore installation vessel 104, including the offshore installation vessel hydraulic control system 218 and the push down actuators 216. The offshore installation vessel hydraulic control system 218 is shown controlling and managing the hydraulic components of the offshore installation vessel 104, including the push down actuators 216.

[0138] In some examples, the offshore installation vessel hydraulic control system 218 is part of the offshore installation vessel 104 and is configured to control and manage the hydraulic components of the offshore installation vessel 104. The offshore installation vessel hydraulic control system 218 includes a hydraulic reservoir, a hydraulic pump, hydraulic hoses, and a controller, similar to the monopile transportation vessel 102. The offshore installation vessel hydraulic control system 218 is designed to provide precise control over the hydraulic components and to ensure reliable operation of the offshore installation vessel 104.

[0139] Figures 6 to 14 show a series of views (both side views and perspective views) of the offshore installation system 100 in operation. The operation of the offshore installation system 100 including the monopile transportation vessel 102, the monopile handling mechanism 132, and the offshore installation vessel 104 will now be discussed.

[0140] The transportation of the monopile 110 involves moving the monopile 110 from a storage location to the offshore installation site. The monopile 110 is loaded onto the monopile transportation vessel 102 in a horizontal position e.g. at a quayside. The loading of the monopile 110 onto the monopile transportation vessel 102 is not shown. The monopile 110 is secured by the monopile handling mechanism 132 during transportation.

[0141] In some examples, the initial positioning of the monopile 110 on the monopile transportation vessel 102 involves placing the monopile 110 on the vessel deck 202 in a horizontal position. The monopile 110 is positioned such that the monopile lower portion 112 is aligned with the first monopile handling mechanism 136 and the monopile upper portion 114 is aligned with the second monopile handling mechanism 134. The monopile 110 is positioned in a manner that allows for secure transportation and efficient handling during the subsequent steps of the method. This can be carried out with a crane (not shown) at a quayside (not shown). In some configurations, securing the monopile 110 for transportation involves engaging the monopile handling mechanism 132 with the monopile 110. The first monopile handling mechanism 136 engages the monopile lower portion 112, and the second monopile handling mechanism 134 engages the monopile upper portion 114. The monopile handling mechanism 132 secures the monopile 110 in place on the vessel deck 202 to prevent movement during transportation. In some implementations, the lashing mechanism 138 is also used to secure the monopile 110 to the first monopile handling mechanism 136 during transport. Again, the securing of the monopile 110 occurs before the monopile transportation vessel 102 travels to the offshore installation vessel 104.

[0142] The monopile transportation vessel 102 is then navigated to the offshore installation vessel 104 as shown in Figure 6. The monopile 110 is transported in a horizontal position to minimise the risk of damage during transportation and to facilitate the subsequent handling and installation processes. As shown in Figure 6, the monopile transportation vessel 102 is aligned with the offshore installation vessel 104. Here part of the monopile 110 is already within the cut-out 124.

[0143] Turning to Figure 7, the monopile 110 is shown having been moved to an inclined position. This involves operating the monopile handling mechanism 132 to move the monopile 110 from the horizontal position to an inclined position. The first monopile handling mechanism 136 slides and pivots the monopile lower portion 112, while the second monopile handling mechanism 134 raises the monopile upper portion 114. The monopile 110 is moved to an inclined position that facilitates the subsequent steps of the method, such as aligning the monopile transportation vessel 102 underneath the hull 122 of the offshore installation vessel 104.

[0144] In some examples, the engagement of the monopile handling mechanism 132 involves activating the hydraulic control system 142 to control the hydraulic components of the monopile handling mechanism 132. The hydraulic control system 142 operates the first monopile handling mechanism 136 and the second monopile handling mechanism 134 to engage the monopile 110 and move it from the horizontal position to the inclined position. As shown in Figure 7, the monopile 110 is inclined before the monopile transportation vessel 102 is moved underneath the hull 122 of the offshore installation vessel 104. This may be required depending on the size of the cut-out 124 and the size of the offshore installation vessel 104. For example, as shown in Figure 6, the depth of the cut-out 124 (the distance from the edge of the hull 122 to the end of the cut-out 124) is less than the length of the monopile 110. This means that the monopile 110 may not be able to be upended and inclined within the cut-out 124. In this example, the size of the offshore installation vessel 104 can be reduced. Accordingly, at least part of the upending operation is carried out before the monopile transportation vessel 102 is moved underneath the hull 122 of the offshore installation vessel 104.

[0145] It is not necessary in other examples however, for the monopile 110 to be inclined before the monopile transportation vessel 102 is moved underneath the hull 122 of the offshore installation vessel 104. For example, the cut-out 124 may have a depth which is longer than the height of the monopile 110.

[0146] Aligning the monopile transportation vessel 102 underneath the hull 122 of the offshore installation vessel 104 involves navigating the monopile transportation vessel 102 to a position directly underneath the hull 122. The monopile transportation vessel 102 is aligned such that the monopile handling mechanism 132 is aligned with a cut-out 124 in the hull 122 as shown in Figure 8. The monopile transportation vessel 102 is positioned in a manner that allows for the application of a downward force by the push down stabilising mechanism 130 and the subsequent movement of the monopile 110 to a vertical position. As can be seen from Figure 8, a portion of the monopile 110 when inclined extends above the offshore installation vessel deck 120. At the same time, the monopile 110 is still engaged with the monopile handling mechanism 132.

[0147] In some implementations, the alignment with the hull 122 of the offshore installation vessel 104 involves positioning the monopile transportation vessel 102 such that the monopile handling mechanism 132 is aligned within the cut-out 124 in the hull 122 of the offshore installation vessel 104. The monopile transportation vessel 102 is positioned in a manner that allows for the application of a downward force by the push down stabilising mechanism 130 and the subsequent movement of the monopile 110 to a vertical position. In some other examples, the offshore installation vessel 104 may not have a cut-out 124. In this case, the monopile transportation vessel 102 is sufficiently long to project underneath the hull 122 and provide the monopile handling mechanism 132 and the monopile 110 adjacent to the offshore installation vessel 104. The centre of the monopile transportation vessel 102 is positioned underneath the offshore installation vessel 104. This arrangement may be less preferable than as shown in the accompanying Figures because the monopile transportation vessel 102 and the offshore installation vessel 104 need to be larger. The cut-out 124 allows for a more compact monopile transportation vessel 102 and offshore installation vessel 104.

[0148] Once the monopile transportation vessel 102, is underneath the offshore installation vessel 104, the monopile transportation vessel 102 is also aligned with the push down stabilising mechanism 130. Exerting a force on the monopile transportation vessel 102 involves operating the push down stabilising mechanism 130 to apply a downward force on the monopile transportation vessel 102 as shown in Figure 9. The push down stabilising mechanism 130 includes a plurality of push down engagement portions 210 that engage a surface of the monopile transportation vessel 102 as discussed above. The activation of the push down stabilising mechanism 130 involves the use of push down actuators 216. In one example, the push down actuators 216 are operatively coupled to the push down engagement portion 210 to move the push down stabilising mechanism 130 between a lowered position, whereby the push down engagement portion 210 engages the monopile transportation vessel 102, and a raised position, whereby the push down engagement portion 210 is disengaged from the monopile transportation vessel 1O2.The downward force increases the buoyancy force on the monopile transportation vessel 102, which stabilises the monopile transportation vessel 102 and the inclined monopile 110 with respect to the offshore installation vessel 104. As can be seen from Figure 9, the monopile transportation vessel 102 sits lower in the water and the water surface 208 is higher on the monopile transportation vessel 102.

[0149] Moving the monopile 110 to a vertical position involves operating the monopile handling mechanism 132 to move the monopile 110 from the inclined position towards a vertical position as shown in Figure 10. The first monopile handling mechanism 136 slides and pivots the monopile lower portion 112 as the skidding sled 154 moves from the first skidding position (as shown in Figure 9) to the second skidding position as shown in Figure 10). At the same time, the second monopile handling mechanism 134 and specifically, the climbing cradle 182 pivots as the skidding sled 154 moves.

[0150] Optionally, a crane 214 and a cable 206 aid the process of moving the monopile 110 from the inclined position towards a vertical position. The cable 206 may provide an additional point of stability for the inclined and near vertical monopile 110. Since the monopile transportation vessel 102 is stabilised by the push down stabilising mechanism 130, the waves do not interfere with the stability of the monopile 110 whilst being upended.

[0151] The monopile 110 as shown in Figure 11 is in a vertical orientation. Here the monopile 110 is still engaged with the monopile handling mechanism 132.

[0152] Figure 12 shows that the monopile 110 is lifted clear from the monopile transportation vessel 102. As shown in Figure 12, the monopile 110 is lifted using the crane 214 and the cable 206. At this point, the push down stabilising mechanism 130 is still exerting a push down force on the monopile transportation vessel 102.

[0153] As shown in Figure 13, the removal of the monopile transportation vessel 102 from underneath the offshore installation vessel 104 involves disengaging the push down stabilising mechanism 130 from the monopile transportation vessel 102 and navigating the monopile transportation vessel 102 away from the offshore installation vessel 104.

[0154] In some implementations, the disengagement of the push down stabilising mechanism 130 involves operating the push down mechanism 130 to retract the push down engagement portions 210 from the surface of the monopile transportation vessel 102. The push down stabilising mechanism 130 is retracted, releasing the downward force on the monopile transportation vessel 102.

[0155] In some examples, the movement of the monopile transportation vessel 102 involves navigating the monopile transportation vessel 102 away from the offshore installation vessel 104 as shown in Figure 14. The monopile transportation vessel 102 is navigated away from the offshore installation vessel 104 using its own propulsion system or with the assistance of a tug 106 or another vessel. The monopile transportation vessel 102 is moved to a safe distance from the offshore installation vessel 104 to allow for the next stage of the installation process.

[0156] The handling of the monopile 110 with the monopile gripper 128 involves operating the monopile gripper 128 to grip and secure the monopile 110 as also shown in Figure 14. The monopile gripper 128 is mounted on the offshore installation vessel 104 and is designed to securely hold the monopile 110 during the installation process. The monopile gripper 128 has been moved into a position overhanging the cut-out 124. The monopile gripper 128 then grips the monopile 110 in the vertical orientation ready for installation into the seafloor 118.

[0157] The installation of the monopile 110 into the seafloor 118 involves operating the monopile gripper 128 and the crane 214 to position and drive the monopile 110 into the seafloor 118. The monopile gripper 128 securely holds the monopile 110, while the crane 214 lifts and positions the monopile 110 over the installation site. The monopile 110 is then driven into the seafloor 118 using a pile driving hammer (not shown) or other suitable device. The monopile 110 is installed into the seafloor 118 to a predetermined depth to ensure stability and structural integrity. Once the monopile 110 is fully installed, the monopile gripper 128 releases the monopile 110, and the installation process is complete.

[0158] The terminology used herein is for the purpose of describing particular aspects only and is not intended to be limiting of the disclosure. As used herein, the singular forms "a," "an," and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items. It will be further understood that the terms "comprises," "comprising," "includes," and / or "including" when used herein specify the presence of stated features, integers, actions, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, integers, actions, steps, operations, elements, components, and / or groups thereof. It will be understood that, although the terms first, second, etc., may be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another. For example, a first element could be termed a second element, and, similarly, a second element could be termed a first element without departing from the scope of the present disclosure.

[0159] Relative terms such as "below" or "above" or "upper" or "lower" or "horizontal" or "vertical" may be used herein to describe a relationship of one element to another element as illustrated in the Figures. It will be understood that these terms and those discussed above are intended to encompass different orientations of the device in addition to the orientation depicted in the Figures. It will be understood that when an element is referred to as being "connected" or "coupled" to another element, it can be directly connected or coupled to the other element, or intervening elements may be present. In contrast, when an element is referred to as being "directly connected" or "directly coupled" to another element, there are no intervening elements present.

[0160] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs. It will be further understood that terms used herein should be interpreted as having a meaning consistent with their meaning in the context of this specification and the relevant art and will not be interpreted in an idealised or overly formal sense unless expressly so defined herein.

[0161] It is to be understood that the present disclosure is not limited to the aspects described above and illustrated in the drawings; rather, the skilled person will recognize that many changes and modifications may be made within the scope of the present disclosure and appended claims. In the drawings and specification, there have been disclosed aspects for purposes of illustration only and not for purposes of limitation, the scope of the disclosure being set forth in the following claims.

Claims

Claims1. An offshore installation system (100) for handling a monopile (110), the system comprising: a monopile transportation vessel (102) configured to transport the monopile (110) in a horizontal position; a monopile handling mechanism (132) mounted on the monopile transportation vessel (102) and configured to secure the monopile (110) during transportation and to move the monopile (110) to an inclined position; an offshore installation vessel (104) having a hull (122) and a plurality of moveable legs (126) wherein the hull (122) is positioned out of the water when moveable legs (126) engage the seafloor (118); and a push down stabilising mechanism (130) mounted on the offshore installation vessel (104) and configured to apply a downward force on the monopile transportation vessel (102) to increase a buoyancy force on the monopile transportation vessel (102) when the monopile transportation vessel (102) is positioned underneath the hull (122) to stabilise the monopile transportation vessel (102) and the inclined monopile (110) with respect to the offshore installation vessel (104).

2. The offshore installation system (100) according to claim 1 , wherein the monopile handling mechanism (132) is configured to move the monopile (110) from the inclined position towards a vertical position after the push down stabilising mechanism (130) exerts the push down force on the monopile transportation vessel (102).

3. The offshore installation system (100) according to claims 1 or 2, wherein the monopile handling mechanism (132) comprises a first monopile handling mechanism (136) configured to engage a monopile lower portion (112) and a second monopile handling mechanism (134) configured to engage a monopile upper portion (114).

4. The offshore installation system (100) according to claim 3, wherein the first monopile handling mechanism (136) is configured to slide and pivot the monopile lower portion (112) as the monopile (110) moves from the horizontal position to the inclined position.

5. The offshore installation system (100) according to claims 3 or 4, wherein the second monopile handling mechanism (134) is configured to raise the monopile upper portion (114) as the monopile (110) moves from the horizontal position to the inclined position.

6. The offshore installation system (100) according to any one of claims 3 to 5, further comprising a hydraulic control system (142) configured to control and manage hydraulic components of the monopile handling mechanism (132).

7. The offshore installation system (100) according to any one of claims 1 to 6, wherein the offshore installation vessel (104) comprises a cut-out (124) in the hull (122) configured to align with the monopile handling mechanism (132) when the monopile transportation vessel (102) is positioned underneath the hull (122) and when the monopile (110) is in an inclined position.

8. The offshore installation system (100) according to any one of claims 1 to 7, wherein the push down stabilising mechanism (130) comprises a plurality of push down engagement portions (210) configured to engage a surface of the monopile transportation vessel (102) and apply the downward force.

9. The offshore installation system (100) according to claim 8, wherein the push down engagement portions (210) are configured to engage a vessel deck (202) of the monopile transportation vessel (102).

10. The offshore installation system (100) according to any one of claims 1 to 9, further comprising a monopile gripper (128) mounted on the offshore installation vessel (104) and configured to grip and secure the monopile (110) for handling and installation.

11. The offshore installation system (100) according to any one of claims 1 to 10, wherein the monopile transportation vessel (102) comprises a vessel deck (202) having a reciprocal deck receiving portion (204) configured to receive and secure feet portions of the push down stabilising mechanism (130).

12. The offshore installation system (100) according to any one of claims 1 to 11 , wherein the monopile handling mechanism (132) comprises a lashing mechanism (138) configured to secure the monopile (110) to the first monopile handling mechanism (136) during transport.

13. The offshore installation system (100) according to any one of claims 1 to 12, wherein the monopile handling mechanism (132) comprises a skidding sea fastening support (140) configured to securely fasten the second monopile handling mechanism (134) to the vessel deck (202) when the monopile (110) is in the horizontal position.

14. A method of moving and handling a monopile (110) at an offshore installation vessel (104), the method comprising: transporting the monopile (110) on a monopile transportation vessel (102) to the offshore installation vessel (104); moving the monopile (110) on the monopile transportation vessel (102) from a horizontal position to an inclined position with a monopile handling mechanism (132) aligning the monopile transportation vessel (102) underneath the hull (122) of the offshore installation vessel (104); exerting a force on the monopile transportation vessel (102) with a push down stabilising mechanism (130) mounted on the offshore installation vessel (104) to increase the buoyancy force on the monopile transportation vessel (102); and stabilising the monopile transportation vessel (102) and the inclined monopile (110) with respect to the offshore installation vessel (104).

15. The method according to claim 14, further comprising moving the monopile (110) from the inclined position towards a vertical position with the monopile handling mechanism (132) after the push down stabilising mechanism (130) exerts the push down force on the monopile transportation vessel (102).

16. A monopile transportation vessel (102) configured to transport a monopile (110) in a horizontal position, the vessel comprising:a monopile handling mechanism (132) mounted on the vessel and configured to secure the monopile (110) during transportation and to move the monopile (110) to an inclined position at an offshore installation vessel (104); wherein the monopile handling mechanism (132) comprises a first monopile handling mechanism (136) configured to engage a monopile lower portion (112) and a second monopile handling mechanism (134) configured to engage a monopile upper portion (114); and a vessel deck (202) configured to receive push down engagement portion (210) of a push down stabilising mechanism (130) mounted on an offshore installation vessel (104) arranged to increase a buoyancy force on the monopile transportation vessel (102) when the monopile transportation vessel (102) is positioned underneath the hull (122) of the offshore installation vessel (104) such that the monopile transportation vessel (102) and the inclined monopile (110) are stabilised with respect to the offshore installation vessel (104).

17. The monopile transportation vessel (102) according to claim 16, wherein the monopile handling mechanism (132) is configured to move the monopile (110) from the inclined position towards a vertical position after the push down stabilising mechanism (130) exerts the push down force on the monopile transportation vessel (102).

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