Ships

Abstract

The vessel comprises a hull, the hull including a circumferential wall, a deck, and a riveting hinge, the riveting hinge comprising a frame attached to at least one of the deck and the hull at a position along the circumferential wall, and a support member, the support member including a bottom, two legs positioned at a distance from each other and extending from the bottom, and a support surface between the legs for supporting a monopile. The support members are attached to the frame through support member pivots at each leg, the support member pivots having a common axis of rotation at a fixed distance from the bottom of the support members and extending in a direction along the circumferential wall at the position of the riveting hinge. The support members have a monopile receiving position, which is a rotational position relative to the common axis of rotation of the support member pivots, in which the bottoms of the support members are located below the common axis of rotation of the support member pivots and the support surface faces upward. The support members also have a monopile erection position that is a rotational position of the support member pivots about a common rotation axis in which the support surfaces are located outside the circumferential wall and face away from the circumferential wall at the erection hinge locations. The frame includes a lifting mechanism for lowering the support member pivots to a position of the support member pivots in the monopile receiving location of the support members.

Description

[Technical field]

[0001] The present invention relates to a watercraft comprising a hull, the hull including a circumferential wall, a deck, and a tilt hinge, the tilt hinge including a frame attached to at least one of the deck and the hull at a position along the circumferential wall, and a support member, the support member including a bottom, two legs positioned at a distance from each other and extending from the bottom, and a support surface between the legs for supporting a monopile, the support member being attached to the frame through a support member pivot at each leg, the support member pivot being pivoted from the bottom of the support member to the frame. The support members have a common axis of rotation at a certain distance from the circumferential wall and extend in a direction along the circumferential wall at the position of the erection hinge, and have a monopile receiving position, which is a rotational position relative to the common axis of rotation of the support member pivots in which the bottom of the support member is located below the common axis of rotation of the support member pivots and the support surface faces upward, and a monopile erection position, which is a rotational position relative to the common axis of rotation of the support member pivots in which the support surface is located outside the circumferential wall and faces away from the circumferential wall at the position of the erection hinge. [Background technology]

[0002] In the prior art, such a vessel is known. This known vessel is used for installing a monopile on the seabed. The monopile is transported horizontally by the vessel to an installation site offshore. At the installation site, the monopile to be installed on the seabed is lifted by a lifting carriage and transferred to the erection line of the erection hinge, where it is lowered and positioned on the bearing surface of the erection hinge. The crane then hoists the monopile at a certain distance from the support member pivot so that the monopile is erected by the crane while supported by the erection hinge. In the monopile erection position, the bearing surface is located outside the circumferential wall of the vessel so that the monopile can extend upright outside the circumferential wall of the vessel at the position of the erection hinge. After the monopile erection step, the monopile is moved by the crane to a gripper, where it is placed on the seabed. A pile driving device is then placed on the monopile and drives it into the seabed. A drawback of the known vessel is that lifting the monopile before it has been positioned on the bearing surface of the support member can lead to an unstable situation. Summary of the Invention [Problem to be solved by the invention]

[0003] It is an object of the present invention to provide a vessel which facilitates the process of positioning a monopile on the bearing surface of a bearing member. [Means for solving the problem]

[0004] This object is achieved by means of a vessel according to the invention, in which the frame comprises a lifting mechanism for lowering the support member pivot relative to its position in the monopile receiving position of the support member.

[0005] When the support member pivots are at a lower height level than the monopile receiving position of the support members, the monopile can be lifted only to a relatively low height level relative to the deck by the lifting cart to move the monopile above one of the support member pivots to position the monopile on the erection line above the bearing surface. This is advantageous with respect to the stability of the monopile on the lifting cart. The lifting cart can prevent a crane on the vessel from being used to move the monopile from the monopile storage location on the deck to the erection line. After the monopile arrives at the erection line and is positioned above the bearing surface, the lifting mechanism of the erection hinge can move the support member pivot upwards so that the monopile can be received between the legs of the support members. After the support member achieves its monopile receiving position, the monopile can be lowered by the lifting cart until the monopile is located on the bearing surface.

[0006] The common axis of rotation of the support member pivots may be located outside the circumferential wall in the monopile receiving position, which gives the opportunity to keep the common axis of rotation of the support members in the same position in both the monopile receiving position and the monopile erecting position of the support members, so that the support members only rotate between the monopile receiving position and the monopile erecting position.

[0007] The support member is U-shaped.

[0008] In a particular embodiment, the lifting mechanism comprises a support member support attached to the support member through a support member pivot and attached to one of the deck and the hull through a support pivot having a rotation axis parallel to the rotation axis of the support member pivot, the support member support being rotatable about the rotation axis of the support pivot by a drive device. Rotating the support member support changes the height level of the common rotation axis of the support member pivots relative to the deck. The support member support may be arranged such that when rotated outwardly from the circumferential wall of the hull at the erection hinge, the support member moves downwardly next to the circumferential wall such that at least a part of the support member can move to a position below the level of the deck.

[0009] The support member support may be rigid such that the distance between the common axis of rotation of the support member pivots and the axis of rotation of the support pivot is fixed.

[0010] In one embodiment, the lifting mechanism comprises a four-bar linkage, wherein the deck forms a first bar of the four-bar linkage, while the second bar is attached to the deck through a second bar pivot having an axis of rotation parallel to the common axis of rotation of the support member pivots, the third bar is attached to the deck through a third bar pivot having an axis of rotation parallel to the axis of rotation of the second bar pivot, and the fourth bar is formed by an upper link, wherein the upper link is attached to the second bar through a first upper link pivot having an axis of rotation parallel to the axis of rotation of the second bar pivot and is attached to the third bar through a second upper link pivot having an axis of rotation parallel to the axis of rotation of the third bar pivot, the support member is attached to at least one of the second bar and the upper link through the support member pivot, and the second bar is rotatable about the axis of rotation of the second bar pivot by the drive device.

[0011] The first upper link pivot and the support member pivot are adapted so that their axes of rotation coincide, meaning that the second bar, the upper link, and the support member can rotate relative to each other about a single axis of rotation.

[0012] In one embodiment, the third bar is extendable by an actuator such that the rotation axis of the third bar pivot and the rotation axis of the second upper link pivot are adjustable, the lifting mechanism comprises an arm attached to at least one of the upper link and the third bar through the first arm pivot on the one hand and to the deck through the second arm pivot on the other hand, the first and second arm pivots having rotation axes parallel to each other and parallel to the rotation axis of the third bar pivot, the rotation axis of the third bar pivot being located between the rotation axis of the second bar pivot and the rotation axis of the second arm pivot, and the drive device comprises a third bar including an actuator, an upper link, a third bar pivot, a first upper link pivot, a support member pivot, a first arm pivot, a second upper link pivot, an arm, and a second arm pivot.

[0013] The actuator may be a linear actuator such as a hydraulic cylinder. When the actuator changes the distance between the axis of rotation of the third bar pivot and the axis of rotation of the second upper link pivot, the arm rotates, and therefore the upper link rotates the second bar. Thus, when the actuator shortens the distance between the axis of rotation of the third bar pivot and the axis of rotation of the second upper link pivot, the arm and the third bar and the second bar rotate in a direction away from the circumferential wall at the position of the erection hinge. In this case, the erection hinge may be changed to a folded state in which the support member pivot and the second upper link pivot are located at a lower level than when the support member is in the monopile receiving position.

[0014] The first arm pivot and the second upper link pivot may be adapted so that their axes of rotation coincide, meaning that the third bar, the upper link, and the arm can rotate relative to each other about a single axis of rotation.

[0015] In a preferred embodiment, the arm is an articulated arm and comprises two arm parts attached to each other through an intermediate pivot with a rotation axis parallel to the rotation axes of the first and second arm pivots, the drive device is a first drive device and the frame further comprises a second drive device for rotating the arm parts relative to each other. This embodiment provides the opportunity to configure the frame in such a way that when the arm parts are rotated relative to each other, the arm pulls the third bar and the second bar in a direction from the outside of the circumferential wall towards the circumferential wall at the position of the erection hinge. Thus, the support members are also moved in a direction from the outside of the circumferential wall towards the circumferential wall at the position of the erection hinge. This is an advantageous movement of the support members after they have arrived at the monopile erection position, because the support surface is retracted from the monopile in the erected position, allowing easy further handling of the monopile, i.e. movement to the gripper, without colliding with the support members. The frame may be configured such that in this position of the erection hinge, sometimes referred to as the retracted position, the majority of the support members are located above the deck, within the circumferential wall of the hull. A further advantage of having the erection hinge retracted towards the hull is that the crane does not have to reach as far to move the monopile up to the gripper, which minimises the risk of overloading the crane and allows heavier piles to be handled.

[0016] In one embodiment, the second bar of the four-bar linkage is formed by the support member support, the second bar pivot is formed by the support pivot, and the first upper link pivot and the support member pivot are adapted so that their axes of rotation are coincident.

[0017] In a particular embodiment, the vessel comprises a lifting cart for lifting the monopile in a horizontal position, the lifting cart comprising a chassis drivable in a direction of movement on the deck and an arc-shaped platform extending between a first edge and a second edge and attached to the chassis, the platform comprising a support surface for supporting the monopile in a horizontal position, the support surface being configured to lie on an imaginary cylinder having a substantially circular cross-section and a longitudinal centerline extending transversely to the direction of movement when supporting the monopile, the platform being liftable relative to the chassis and rotatable relative to the chassis about a rotation axis substantially coinciding with the centerline between a monopile support position and a monopile approach position, the first edge being located at a lower height level in the monopile approach position than in the monopile support position, and the second edge being located at a higher height level in the monopile approach position than in the monopile support position.

[0018] This means that when the cradle is in the monopile approach position, it can be moved to the monopile stored on the deck, and when the support surface is at or near the monopile, it can be rotated circumferentially around the monopile to the monopile support position. The cradle can then be lifted relative to the chassis and transported towards the erection hinge. The advantage of a rotatable cradle is that due to the first edge being relatively low in the monopile approach position of the cradle, it can take in a monopile stored at a relatively low height above the deck, while storage at a relatively low height is favourable for the stability of the vessel.

[0019] The first edge and the second edge may be located at substantially the same height level in case of a monopile support position, in other words the cradle may be symmetrical with respect to a vertical plane in which the axis of rotation lies.

[0020] The angular distance between the first edge and the second edge is preferably less than 180° to facilitate positioning of the cradle around the monopile.

[0021] In one embodiment, the platform comprises a platform frame on which discrete support elements are mounted adjacent to one another in an angular direction about an axis of rotation to together form a support surface, the support elements being movable relative to the platform frame such that when they engage the monopile to be lifted they automatically assume a position and orientation which conforms to the circumference of the monopile.

[0022] At least two support elements may be mounted on a rocker, which is attached to the mounting frame and rotatable relative to the mounting frame about an axis parallel to the axis of rotation in order to force the support elements into a position and orientation that conforms to the circumference of the monopile.

[0023] It should be noted that a lifting platform including a rotatable platform is not necessarily combined with a lifting hinge. In other words, the present invention also relates to the following items:

[0024] Item 1: A lifting cart for lifting a monopile in a horizontal position, comprising a chassis drivable in a movement direction and an arc-shaped base extending between a first edge and a second edge, the base having a support surface for supporting the monopile in a horizontal position, the support surface being configured to be located on an imaginary cylinder having a substantially circular cross-section and a longitudinal centerline extending transversely to the movement direction when supporting the monopile, the base being liftable relative to the chassis and rotatable relative to the chassis about a rotation axis substantially coinciding with the centerline between a monopile support position and a monopile approach position, the first edge being located at a lower height level in the monopile approach position than in the monopile support position, and the second edge being located at a higher height level in the monopile approach position than in the monopile support position.

[0025] Item 2: A lifting car according to item 1, wherein the first and second edges are located at substantially the same height when in a monopile support position.

[0026] Item 3: The lifting cart according to item 1 or 2, wherein the angular distance between the first edge and the second edge is less than 180°.

[0027] Item 4: A lifting cart according to any one of items 1 to 3, wherein the cart comprises a cart frame on which discrete support elements are mounted adjacent to one another in an angular direction about an axis of rotation and together form a support surface, the support elements being movable relative to the cart frame such that, when engaging with the monopile to be lifted, they automatically assume a position and orientation which matches the circumference of the monopile.

[0028] Item 5: A lifting cart according to item 4, wherein the at least two support elements are attached to rockers, and the rockers are attached to the platform frame and are rotatable relative to the platform frame about an axis parallel to the rotation axis.

[0029] Item 6: A lifting cart according to any one of items 1 to 5, wherein the cradle is liftable relative to the chassis by a plurality of actuators, at least one of which is rotatably attached to the chassis on a side of the cradle where a first edge of the cradle is located and extends vertically in the monopile support position, and the actuator is rotatable relative to the chassis in the monopile approach position. Because the actuator may obstruct the cradle from approaching the monopile in its monopile approach position, the actuator may rotate away from the vertical position, for example to a horizontal position.

[0030] From the above it is apparent that when the support member pivot is lowered and the platform rotated about the monopile to the monopile support position, the monopile remains close to the deck and there is no need to raise the monopile too high to clear a blockage. Because the monopile is relatively low, the loads are kept relatively controllable.

[0031] The invention will now be described, by way of example only, with reference to schematic drawings showing embodiments of the invention. [Brief description of the drawings]

[0032] [Figure 1] 1 is a perspective view of one embodiment of a watercraft according to the present invention; FIG. [Diagram 2] 2 is a view similar to FIG. 1 but showing the vessel in a different state; [Diagram 3] 2 is a view similar to FIG. 1 but showing the vessel in a different state; [Figure 4] FIG. 2 is an enlarged view of a portion of the vessel shown in FIG. 1 showing a portion of the erection hinge in a monopile receiving condition as shown in FIG. 1. [Diagram 5] FIG. 5 is a diagram similar to FIG. 4, but showing the erection hinge in the monopile erection state as shown in FIG. [Figure 6] FIG. 5 is a diagram similar to FIG. 4, but showing the erection hinge in the folded state. [Figure 7] FIG. 6 is a view similar to FIG. 5, but showing the erection hinge in the retracted state. [Figure 8] 1 is a perspective view of an embodiment of a lifting cart according to the present invention; FIG. [Figure 9] 9 is a side view of the lift car shown in FIG. 8 showing successive steps of operating the lift car. [Figure 10] 9 is a side view of the lift car shown in FIG. 8 showing successive steps of operating the lift car. [Figure 11] 9 is a side view of the lift car shown in FIG. 8 showing successive steps of operating the lift car. [Figure 12] 12 is a diagram similar to FIG. 8 but on a larger scale, showing the situation as shown in FIG. 11. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0033] Figure 1 shows a floating vessel 1 for installing a monopile 2 on the seabed. The vessel 1 has a hull including a circumferential wall 3 and an upper deck 4. A crane 5 for hoisting the monopile 2 is mounted on the upper deck 4. The vessel 1 also comprises a gripper (not shown) for guiding the monopile 2 longitudinally as it is driven into the seabed.

[0034] 1, under operating conditions, monopiles 2 are transported horizontally by vessel 1 from a production facility to an offshore installation site. At the installation site, each monopile 2 is erected by crane 5 while supported by erection hinges 6.

[0035] 1 to 3 show the process of erecting the monopile 2. In a first step, the monopile 2 is lifted from two fixed monopile stands 7 by a lifting carriage 8. The fixed monopile stands 7 are mounted on the upper deck 4 at a distance from each other, in this case at both ends of the circumferential wall 3 of the vessel, i.e. on the port and starboard sides. The lifting carriage 8 is provided with a monopile stand 9 for safely supporting the monopile 2 and transporting it at the erection hinge 6 to the erection line running transversely of the vessel 1. The lifting carriage 8 is drivable along rails 10 on the upper deck 4. The fixed monopile stands 7 and the monopile stands 9 of the lifting carriage 8 have discrete support elements forming a circular arc, although alternative shapes are also conceivable.

[0036] Before the lifting car 8 including the monopile 2 arrives at the erection line, the erection hinge 6 is put into a folded state, as will be described below. After the lifting car 8 including the monopile 2 arrives at the erection line, the erection hinge 6 is changed from the folded state to a monopile receiving state, and the monopile 2 is lowered to be located on the erection hinge 6 and the fixed monopile support 7 at the erection line. The crane 5 then hoists the monopile 2 away from the erection hinge 6 so that the monopile 2 is erected by the crane 5 while supported by the erection hinge 6. After the monopile 2 is suspended vertically from the cable of the crane 5, it is moved by the crane 5 to a gripper, where it is placed on the seabed. The cable is then separated from the monopile 2, and a pile driving device (not shown) is placed on the monopile 2 by the crane 5 to drive the monopile 2 into the seabed.

[0037] FIG. 4 shows the erection hinge 6 in more detail. The erection hinge 6 comprises a frame 11 attached to the deck 4 at a position along the circumferential wall 3 of the hull, in this case on the port side. The frame 11 comprises two identical four-bar linkages extending parallel to each other in respective vertical planes. The first bar of each bar linkage of the four-bar linkage is formed by the upper deck 4, the second bar by the support 12, the third bar by the extensible rod 13 and the fourth bar by the upper link 14. The support 12 is attached to the upper deck 4 through a support pivot 15 with a rotation axis parallel to the circumferential wall 3 of the hull on the port side. The extensible rod 13 is attached to the upper deck 4 through a third bar pivot 16 with a rotation axis parallel to that of the support pivot 15. The upper link 14 is attached to the support 12 through a first upper link pivot 17 having a rotation axis parallel to the rotation axis of the support pivot 15, and is attached to an extendable rod 13 through a second upper link pivot 18 having a rotation axis parallel to the rotation axis of the first upper link pivot 17 and the rotation axis of the third bar pivot 16. The extendable rod 13 is equipped with a hydraulic cylinder for changing the distance between the rotation axis of the third bar pivot 16 and the rotation axis of the second upper link pivot 18.

[0038] The erection hinge 6 further comprises a support member 19 attached to the four-bar linkage through a support member pivot having a common axis of rotation coinciding with the common axis of rotation of the first link pivot 17 of each four-bar linkage. The support member 19 comprises a U-shaped body 20 extending in a first plane and a support bracket extending in a second plane extending perpendicular to the first plane. In this case, the first and second planes intersect each other along the common axis of rotation of the first link pivot 17, although this may be different in alternative embodiments. The U-shaped body 20 has a bottom and two parallel legs pivotally attached to the support 12 and the top link 14 such that the bottom is eccentrically located with respect to the common axis of rotation of the first link pivot 17. Thus, the support 12, the support member 19 and the top link 14 are rotatable relative to each other about the common axis of rotation of the first link pivot 17.

[0039] The U-shaped body 20 comprises discrete support elements which together form an arcuate support surface 22 for supporting the monopile 2 in its radial direction, i.e. when the monopile is in a horizontal position. The support elements may have the same shape and dimensions as the fixed frame 7 on the starboard side. The support bracket 21 comprises a support rod 23 for supporting the monopile 2 in its axial direction, i.e. when the monopile 2 is in a vertical position. This situation is shown in Fig. 3. The support bracket 21 is adjustable so that the distance between the support rod 23 and the support member pivot, i.e. in this case the first link pivot 17, can be changed. This gives the opportunity to bring the support rod 23 into contact with the axial end of the monopile 2 when it is still in a horizontal position on the erection hinge 6, so that the monopile 2 does not slide downwards along the support bracket 21 during the erection process.

[0040] Attached to each of the legs of the U-shaped body 20 of the support member 19 is an annular plate portion 24. The annular plate portions have through holes located at fixed distances from each other about the common axis of rotation of the support member pivot. Each of the supports 12 is provided with a first releasable coupling 25 including an extensible pin that can be selectively inserted into one of the through holes to mechanically couple the support 12 and the corresponding annular plate portion 24.

[0041] The support members 19 can be rotated relative to the supports 12 by adjustment rods 26 rotatably mounted to the respective supports 12 through rod pivots 27 having a common axis of rotation coinciding with the common axis of rotation of the first link pivots 17. Each of the adjustment rods 26 is provided with a second releasable joint 28 including an extendable pin that can be selectively inserted into one of the through holes of the corresponding annular plate portion 24 to mechanically couple the adjustment rods 26 and the corresponding annular plate portion 24 to one another. The adjustment rods 26 are rotatable relative to the respective supports 12 by respective hydraulic cylinders 29 pivotally mounted to the respective supports 12 and the adjustment rods 26. When the pin of the first joint 25 is retracted and the pin of the second joint 28 is inserted into one of the through holes of the respective annular plate portion 24, the support members 19 are rotated relative to the frame 11 upon actuation of the hydraulic cylinders 29.

[0042] The frame 11 further comprises parallel articulated arms 30 pivotally coupled to the respective four-bar linkages. The upper ends of the articulated arms 30 are attached to the respective extendable rods 13 and respective upper links 14 through pivots having a common axis of rotation coinciding with the common axis of rotation of the second upper link pivots 18. The lower ends of the articulated arms 30 are attached to the deck 4 through respective distinct arm pivots 31 having a common axis of rotation parallel to the common axis of rotation of the third bar pivots 16. FIG. 5 shows that the common axis of rotation of the third bar pivots 16 is located between the common axis of rotation of the support pivots 15 and the common axis of rotation of the arm pivots 31.

[0043] Each of the articulated arms 30 has an intermediate pivot 32 having an axis of rotation parallel to and located between the common axis of rotation of the second upper link pivot 18 and the common axis of rotation of the arm pivot 31. Each of the intermediate pivots 32 divides the corresponding articulated arm 30 into two arm portions. The articulated arms 30 can be folded about the common axis of rotation of the intermediate pivot 32 by a respective hydraulic cylinder 33. The hydraulic cylinders 33 are attached to the corresponding arm portions such that when the hydraulic cylinders 33 are in an extended state, the articulated arms 30 extend substantially linearly, and when the hydraulic cylinders 33 are in a retracted state, the articulated arms 30 are folded outwardly as viewed from the common axis of rotation of the third bar pivot 16.

[0044] The hydraulic cylinder cooperating with the extendable rod 13 forms part of a first drive device of the erection hinge 6 , and the hydraulic cylinder 33 cooperating with the articulated arm 30 forms part of a second drive device of the erection hinge 6 .

[0045] Figure 4 shows the erection hinge 6 in a monopile receiving state with the support member 19 in the monopile receiving position. This means that the bottom of the U-shaped body 20 of the support member 19 is located below the common axis of rotation of the first link pivot 17, the bearing surface 22 faces upwards, while the support bracket 21 extends horizontally. In this position, the monopile 2 can be placed on the bearing surface 22 between the legs of the U-shaped body 20 and on the fixed monopile cradle 7 located on the erection line on the starboard side of the vessel 1. The monopile 2 then extends between the parallel 4-bar linkage and the parallel articulated arms 30. In the monopile receiving position shown in FIG. 4, the dimensions of the frame 11 are such that the upper links 14 extend parallel to the upper deck 4, the extensible bars 13 extend perpendicular to the upper deck 4 and the supports 12 span a plane extending at an angle to the deck 4 as the common axis of rotation of the first link pivots 17 lies outside the hull circumferential wall 3, although it should be noted that the dimensions may be different in alternative embodiments.

[0046] FIG. 5 shows the erection hinge 6 in the monopile erecting state, with the support member 19 in the monopile erecting position. This means that the support member 19 is rotated 90° counterclockwise around the common axis of rotation of the first link pivot 17 relative to the monopile receiving position. In the monopile erecting position of the support member 19, the bearing surface 22 is located outside the circumferential wall 3 at the erection hinge 6 and faces away from the circumferential wall 3. The rotation of the support member 19 is caused by the crane 5 lifting the monopile 2 at the axial end of the support member 19, which is located at a certain distance from the support rod 23 of the support bracket 21. See FIGS. 2 and 3. During the rotation from the monopile receiving position to the monopile erecting position, the pins of the respective first and second joints 25, 28 are retracted.

[0047] FIG. 6 shows the erection hinge 6 in the folded state. In this state, the hydraulic cylinders associated with the respective extensible rods 13 are retracted for the monopile-receiving state, i.e. the deployed state of the erection hinge 6 as shown in FIG. 4, while the hydraulic cylinders 33 associated with the respective articulated arms 30 remain in their extended position. This means that the articulated arms 30 force the extensible rods 13 to rotate about the common axis of rotation of the third bar pivots 16, and thus move the upper links 14 away from the circumferential wall 3 of the hull. The supports 12 thus rotate in the same direction of rotation as the extensible rods 13 about the common axis of rotation of the support pivots 15. In this case, the pins of the first joints 25 are inserted into the corresponding through holes of the annular parts 24, which are aligned with the pins of the first joints 25 in the monopile-receiving state of the erection hinge 6 as shown in FIG. 4. This means that the relative positions of the support members 19 and the supports 12 remain the same while changing from the monopile receiving position as shown in FIG. 4 to the folded position as shown in FIG.

[0048] Figure 6 shows by dashed lines the path followed by the first upper link pivot 17 while moving to the folded state. Figure 6 also shows that the maximum height level of the erection hinge 6 above the deck 4 in the folded state is significantly lower with respect to the unfolded state as shown in Figure 4. This facilitates the positioning of the monopile 2 on the erection line, since the required lifting height of the lifting cart 8 can be minimized. It is noted that the use of the lifting cart 8 instead of the crane 5 for moving the monopile 2 from the monopile storage area to the erection line has several advantages, such as safety advantages.

[0049] In fact, before the lifting carriage 8 containing the monopile 2 arrives at the erection line, the erection hinge 6 is set in a folded state as shown in Fig. 6. The monopile 2 is then moved by the lifting carriage 8 to the erection line at a slightly elevated level above the upper deck 4 until it extends above the bearing surface 22 and the fixed monopile cradle 7 located on the starboard side of the vessel 1. The erection hinge 6 is then moved from the folded state as shown in Fig. 6 back to the monopile receiving position as shown in Fig. 4, after which the lifting carriage 8 lowers the monopile 2 until it is located on the bearing surface 22 and the fixed monopile cradle 7 located on the starboard side of the vessel 1. The extendable rod 13, the upper link 14 and the articulated arm 30, which comprise cooperating hydraulic cylinders, form part of a first drive device for rotating the support 12 around a common axis of rotation of the support pivot 15.

[0050] 6 shows that in the folded position, most of the erection hinge 6 is lowered to a level below the upper deck 4, outside the hull circumferential wall 3. The support 12, the upper link 14, the extendable rod 13 including the cooperating hydraulic cylinder, and the articulated arm 30, as well as the support pivot 15, the first and second upper link pivots 17, 18, and the arm pivot 31 form part of a lifting mechanism for lowering the support member pivots to their positions in the monopile receiving position of the support member 19.

[0051] FIG. 7 shows the retracted state of the erection hinge 6 that can be set after the monopile 2 has been erected, i.e. after the erection hinge 6 has reached the monopile erection state as shown in FIG. 5. As mentioned above, in this situation the crane 5 needs to transport the monopile 2 from the erection hinge 6 to the gripper. To achieve the folded state as shown in FIG. 7 from the monopile erection state as shown in FIG. 5, the hydraulic cylinders of each extensible rod 13 remain in their extended position. The hydraulic cylinders 33 of the articulated arms 30 are retracted so that the articulated arms 30 are folded outwards. Thus, the extensible rods 13 and the supports 12 are forced to rotate clockwise around the common rotation axis of the third bar pivot 16 and the support pivot 15, respectively. This means that the support member 19 including the support bracket 21 is moved in a direction from the outside of the circumferential wall 3 towards the hull circumferential wall 3 at the erection hinge 6 location. Additionally, the hydraulic cylinder 29 cooperating with the support 12 and the adjusting rod 26 can be operated so that the pin of the second joint 28 can be inserted into the cooperating hole of the respective annular plate portion 24, after which the hydraulic cylinder 29 is operated so that the adjusting rod 26 approaches or contacts the corresponding support 12 and the support bracket 21 approaches or contacts the circumferential wall 3, as shown in Figure 7. In this case, the pin of the first releasable joint 25 may be retracted.

[0052] 7 shows that the shape and dimensions of the frame 11 are selected such that, in the retracted state of the erection hinges 6, the support brackets 21 hang along the circumferential wall 3 of the hull, while the largest part of the U-shaped body 20 of the support member 19 is positioned 9 above the upper deck 4. Thus, the erected monopile 2 hanging from the crane 5 is released from the erection hinges 6, thereby enabling the crane 5 to transport the monopile 2 towards the gripper without colliding with the erection hinges 6.

[0053] Figure 8 shows an embodiment of a lifting cart 8 according to the invention. The lifting cart is also seen in figures 1 to 3 and serves to lift and transport the monopile 2 from its position on the upper deck 4, where it is stored in the erection line at the erection hinge 6. The lifting cart 8 comprises a rectangular chassis 34 which can be driven along the rails 10. The chassis 34 supports rectangular carriages 35 which can be lifted relative to the chassis 34. The monopile carriers 9 are mounted on the carriages 35 at a distance from each other. Each of the monopile carriers 9 has an arc-shaped carrier frame 37 which is rotatable relative to the carriage 35 around an axis of rotation AR which runs across the rails 10. See figures 9 to 11. On the concave side of the carrier frame 37, discrete support elements 38 are mounted next to each other in the angular direction about the axis of rotation AR. The support elements 38 of each monopile cradle 9 form a part-circular cylindrical support surface supporting the monopile 2. The support surface lies on an imaginary cylinder having a substantially circular cross section and a longitudinal centre line substantially coinciding with the axis of rotation AR. In the embodiment shown in Figures 8 to 12, the cradle frame 37 is supported by respective arc-shaped cradle frame bearings 40 along which the cradle frame 37 can slideably move in a rotational direction about the axis of rotation AR. The cradle frame bearings 40 are fixed to the bogie 35.

[0054] 8 to 12 show that a pair of two support elements 38 are mounted on respective rockers 36, which are mounted on a frame 37 and are rotatable relative to the frame 37 about an axis parallel to the axis of rotation AR. This arrangement forces the support elements 38 to automatically assume a position and orientation that properly matches the circumference of the monopile 2 when the frame 35 is raised and the support elements 38 engage the monopile 2. This is advantageous when the part of the monopile 2 supported by the support elements 38 is not strictly a cylinder with a circular circumference.

[0055] 9-11 show that each of the monopile cradles 9 extends between a first edge 9a and a second edge 9b. In this case, the support element 38 forms an end of each monopile cradle 9 including the first edge 9a and the second edge 9b, but in alternative embodiments the cradle frame 37 may have the first edge 9a and the second edge 9b. Each of the monopile cradles 9 is rotatable with respect to the carriage 35 between a monopile support position as shown in Figs. 10-12 and a monopile approach position as shown in Figs. 8 and 9. In this embodiment, the first edge 9a and the second edge 9b are located at substantially the same height level in the monopile support position. In the monopile approach position, the first edge 9a is located at a lower height level than in the monopile support position. Similarly, in the monopile approach position the second edge 9b is located at a higher height level than in the monopile support position.

[0056] When the monopile 2 needs to be transported from its storage position to the erection line, the lifting car 8 can be driven towards the stored monopile 2 in its monopile approach position as shown in Fig. 8. Just before the monopile cradle 9 contacts the monopile 2 as shown in Fig. 9, it can be rotated to move circumferentially around the monopile 2 until it reaches the monopile support position as shown in Fig. 10. The car 35 can then be lifted so that the monopile 2 is engaged by the support element 38 as can be seen in Fig. 11 and is then lifted from the fixed monopile cradle 7 on the deck 4 and transported to the erection line. Due to the relatively low first edge 9a in the monopile approach position, the lifting car 8 can take the monopile 2 stored on the fixed monopile cradle 7 on the upper deck 4 at a relatively low height level. Advantageously, the low storage level forms a stable vessel 1.

[0057] 12 shows how the bogie 35 is lifted relative to the chassis 34. This is done by four hydraulic cylinders 39 at each corner of the chassis 34 and the bogie 35. The hydraulic cylinders 39 cooperate with two pairs of rods 41 on either side of the bogie 35. Each pair of rods 41 is rotatable relative to the bogie 35 about a common axis of rotation that crosses the rail 10. The corresponding hydraulic cylinders 39 of each pair of rods 41 are rotatably attached to the rods 41 at a fixed distance from the common axis of rotation and are rotatably attached to the chassis 34. This provides sufficient space to accommodate the relatively large hydraulic cylinders 39.

[0058] When the carriage 35 is in a lower position, i.e. when the hydraulic cylinders 39 are retracted, the common axis of rotation of each pair of rods 41 coincides with the common axis of rotation of the corresponding hydraulic cylinder 39 when it is rotatably mounted on the chassis 34. This allows the cylinders 39 including the pairs of rods 41 to rotate between a vertical position in the monopile approach position and a horizontal position. The latter situation is shown in Figs. 8 and 9, and the former situation is shown in Figs. 10 to 12. A hydraulic cylinder 42 is attached to the rods 41 and the carriage 35 to rotate the cylinders 39 including the rods 41 between a vertical position and a horizontal position. This means that on the side of the monopile frame 9 where the first edge 9a is located, for example, the hydraulic cylinder 39 is rotated away from its vertical position to a horizontal position, so that the hydraulic cylinder 39 does not hinder the monopile frame 9 from approaching the monopile 2 in the monopile approach position, as can be seen in Fig. 8. It will be apparent that in this embodiment the rods 41 and cooperating cylinders 39 provide the opportunity to retrieve monopiles 2 stored at a relatively low level. Nevertheless, alternative systems for rotating and lifting the monopile platform 9 are conceivable.

[0059] The invention is not limited to the embodiments shown in the drawings and described above, which may be varied differently within the scope of the claims and their technical equivalents. [Explanation of symbols]

[0060] 1 ship 2. Monopile 3 Circumferential wall 4. Upper Deck 5. Crane 6. Lifting hinge 7 Monopile Mounting 8 Lifting cart 9 Monopile Mounting 9a First edge 9b Second edge 10 Rail 11 Frame 12 Support 13 Extendable Rod 14 Top Link 15 Support Pivot 16 Third Bar Pivot 17 First upper link pivot 18 Second upper link pivot 19 Supporting member 20 U-shaped body 21 Support bracket 22 Circular support surface 23 Support rod 24 Annular plate part 25 First releasable coupling 26 Adjustment rod 27 Rod pivot 28 Second releasable coupling 29 Hydraulic Cylinder 30 Articulated Arm 31 Arm pivot 33 Hydraulic Cylinder 34 Chassis 35 Trolley 36 Locker 37 Arc-shaped stand frame 38 Supporting elements 40 Arc-shaped frame bearing 41 Rod 42 Hydraulic cylinder

Claims

1. A vessel (1) having a hull, the hull including a circumferential wall (3), a deck (4) and a tilt hinge (6), the tilt hinge (6) including a frame (11) attached to at least one of the deck (4) and the hull at a position along the circumferential wall, and a support member (19), the support member (19) including a bottom, two legs positioned at a distance from each other and extending from the bottom, and a support surface (22) between the legs for supporting a monopile (2), the support member (19) being attached to the frame (11) through a support member pivot (17) at each of the legs, the support member pivot (17) having a common axis of rotation at a fixed distance from the bottom of the support member and extending along the circumferential wall (3) at the position of the tilt hinge (6). a monopile receiving position which is a rotational position of the support member pivot (17) with respect to the common rotation axis in which the bottom of the support member (19) is located below the common rotation axis of the support member pivot (17) and the support surface (22) faces upward, and a monopile erecting position which is a rotational position of the support member pivot (17) with respect to the common rotation axis in which the support surface (22) is located outside the circumferential wall (3) and faces in a direction away from the circumferential wall (3) at the position of the erecting hinge (6), and the frame (11) is provided with a lifting mechanism (12-18, 30, 31) for lowering the support member pivot (17) with respect to the position of the support member pivot (17) in the monopile receiving position of the support member (19).

2. 2. The ship (1) according to claim 1, wherein in the monopile receiving position, the common axis of rotation of the support member pivots (17) lies outside the circumferential wall (3).

3. 3. The vessel (1) according to claim 1 or 2, wherein the lifting mechanism comprises a support member support (12) attached to the support member (19) through the support member pivot (17) and attached to one of the deck (4) and the hull via a support pivot (15) having a rotation axis parallel to the common rotation axis of the support member pivot (17), the support member support (12) being rotatable about the rotation axis of the support pivot (15) by a drive device (13, 14, 16, 17, 18, 30, 31).

4. 4. The vessel (1) according to claim 3, wherein the support member support (12) is rigid such that the distance between the common rotation axis of the support member pivots (17) and the rotation axis of the support pivot (15) is fixed.

5. The lifting mechanism comprises a four-bar linkage, the deck (4) forming a first bar of the four-bar linkage, while a second bar (12) is attached to the deck (4) via a second bar pivot (15) having an axis of rotation parallel to the common axis of rotation of the support member pivot (17), a third bar (13) is attached to the deck (4) via a third bar pivot (16) having an axis of rotation parallel to the axis of rotation of the second bar pivot (15), and a fourth bar is formed by an upper link (14) which is connected to a first bar pivot (16) having an axis of rotation parallel to the axis of rotation of the second bar pivot (15).

3. The vessel (1) according to claim 1 or 2, wherein a support member (19) is attached to the second bar (12) via an upper link pivot (17) having an axis of rotation parallel to the axis of rotation of the third bar pivot (16) and to the third bar (13) via a second upper link pivot (18) having an axis of rotation parallel to the axis of rotation of the third bar pivot (16), the support member (19) is attached to at least one of the second bar (12) and the upper link (14) via the support member pivot (17), and the second bar (12) is rotatable about the axis of rotation of the second bar pivot (15) by a drive device (13, 14, 16, 17, 18, 30, 31).

6. 6. The vessel (1) according to claim 5, wherein the first upper link pivot (17) and the support member pivot are adapted so that their axes of rotation are coincident.

7. The third bar (13) is extendable by an actuator such that the distance between the axis of rotation of the third bar pivot (16) and the axis of rotation of the second upper link pivot (18) is adjustable, and the lifting mechanism comprises an arm (30) which is attached, on the one hand, to at least one of the upper link (14) and the third bar (13) via a first arm pivot (18) and, on the other hand, to the deck (4) through a second arm pivot (31), and the first and second arm pivots (18, 31) are parallel to each other and are aligned with the third bar pivot (16).

7. The vessel (1) according to claim 5 or 6, wherein the third bar pivot (16) has an axis of rotation parallel to the axis of rotation of the second bar pivot (15) and the axis of rotation of the third bar pivot (16) is located between the axis of rotation of the second bar pivot (15) and the axis of rotation of the second arm pivot (31), and the actuation device comprises the third bar (13) including the actuator, the upper link (14), the third bar pivot (16), the first upper link pivot (17), the support member pivot, the first arm pivot (18), the second upper link pivot (18), the arm (30) and the second arm pivot (31).

8. 8. The vessel (1) according to claim 7, wherein the first arm pivot (18) and the second upper link pivot are adapted so that their axes of rotation are coincident.

9. 9. The vessel (1) according to claim 7 or 8, wherein the arm (30) is an articulated arm and comprises two arm portions attached to each other via an intermediate pivot (32) having an axis of rotation parallel to the axes of rotation of the first and second arm pivots (18, 31), the drive device is a first drive device (13, 14, 16, 17, 18, 30, 31), and the frame (11) further comprises a second drive device (33) for rotating the arm portions relative to each other.

10. 10. The vessel (1) according to claim 3 or 4 in combination with any one of claims 5 to 9, wherein the second bar of the four-bar linkage is formed by the support member support (12), the second bar pivot is formed by the support pivot (15), and the first upper link pivot (17) and the support member pivot (17) are adapted so that their axes of rotation are coincident.

11. The ship (1) comprises a lifting carriage (8) for lifting the monopile (2) in a horizontal position, the lifting carriage (8) comprising a chassis (34) drivable in a direction of movement on the deck (4) and a circular arc-shaped platform (9) extending between a first edge (9a) and a second edge (9b) and attached to the chassis (34), the platform (9) comprising a support surface for supporting the monopile (2) in a horizontal position, the support surface being shaped to lie on an imaginary cylinder having a substantially circular cross section and a longitudinal centerline extending transversely to the direction of movement when supporting the monopile (2).

11. The ship (1) according to any one of claims 1 to 10, wherein the platform (9) is liftable relative to the chassis (34) and rotatable relative to the chassis (34) about a rotation axis (AR) substantially coinciding with the center line between a monopile support position and a monopile approach position, and wherein the first edge (9a) is located at a lower height level in the monopile approach position than in the monopile support position, and the second edge (9b) is located at a higher height level in the monopile approach position than in the monopile support position.

12. The ship (1) according to claim 11, wherein the first edge (9a) and the second edge (9b) are located at substantially the same height level in case of the monopile support position.

13. Ship (1) according to claim 11 or 12, wherein the angular distance between the first edge (9a) and the second edge (9b) is smaller than 180°.

14. 14. The vessel (1) according to any one of claims 11 to 13, wherein the cradle (9) comprises a cradle frame (37) on which discrete support elements (38) are mounted next to each other in an angular direction about the axis of rotation (AR) and together form the support surface, the support elements (38) being movable relative to the cradle frame (37) such that, when engaging with the monopile (2) to be lifted, they automatically assume a position and orientation which adapts to the circumference of the monopile (2).

15. 15. The vessel (1) according to claim 14, wherein at least two support elements (38) are mounted on a rocker (36), said rocker (36) being mounted on said cradle frame (37) and rotatable relative to said cradle frame (37) about an axis parallel to said axis of rotation (AR).

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