Installation stand system, relocation method and system

Abstract

This invention provides a lightweight mounting platform system, a method for moving the platform, and a system for mounting platforms used in yards. [Solution] An installation platform system 100 on which an offshore structure 10 is installed includes a yard-type installation platform S1 on which the offshore structure 10 is installed and which is located in yard Y, and a shipboard-type installation platform on which the offshore structure 10 is installed and which is located on ship B, wherein the yard-type installation platform S1 is made of steel, and the offshore structure 10 includes a fixed-bottom foundation or a jacket-type structure that supports an offshore wind turbine.

Description

Technical Field

[0001] The present disclosure relates to an installation platform system, a moving method, and a system.

Background Art

[0002] Conventionally, grillages have been used, for example, to distribute the self-weight of offshore structures (jackets, spars, etc.) such as offshore wind turbines and offshore oil platforms over a wider area of the structure or ground that supports them. Patent Document 1 discloses a grillage disposed on the deck of a ship so as to correspond to the spacing and configuration of the legs of a heavy load. Patent Document 1 also discloses that steel is used for this grillage. And Patent Document 1 discloses the legs of a jacket placed on a concrete support on the ground of a yard.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, Patent Document 1 only discloses a concrete support for use in a yard. There was room for improvement in reducing the weight of the installation platform for the yard.

[0005] The present disclosure has been made in view of the above circumstances, and an object thereof is to provide an installation platform system, a moving method, and a system capable of reducing the weight of an installation platform for a yard.

Means for Solving the Problems

[0006] <1> The installation platform system according to Aspect 1 of the present disclosure is an installation platform system on which an offshore structure is installed, The aforementioned offshore structure is installed on a yard-type mounting platform that is placed in the yard, The aforementioned offshore structure is installed on a shipboard mounting platform that is placed on the ship, Includes, The aforementioned yard mounting platform is made of steel. The aforementioned offshore structure includes a fixed-bottom foundation or a jacket-type structure that supports an offshore wind turbine. It is characterized by the following: [Effects of the Invention]

[0007] According to this disclosure, it is possible to provide a mounting platform system, a method of movement, and a system that can reduce the weight of mounting platforms for yards. [Brief explanation of the drawing]

[0008] [Figure 1] This is a perspective view of an offshore wind turbine jacket structure system including a mounting base system according to the first embodiment, showing it in a yard. [Figure 2] This is an enlarged view of part II shown in Figure 1. [Figure 3] This is a first side view showing the Leg installed on the first mounting base. [Figure 4] This is a second side view showing the Leg installed on the first mounting base. [Figure 5] This is an enlarged view of section V in Figure 4. [Figure 6] This is a plan view of Figure 4. [Figure 7] This is a front view showing the leg sandwiched between the first and second transport trolleys. [Figure 8] This is a plan view of Figure 7. [Figure 9] This is a perspective view of an offshore wind turbine jacket structure system including a mounting base system according to the first embodiment, showing the system in a state on a ship. [Figure 10] This is a plan view showing an example of the mounting position of the first mounting platform on a ship. [Figure 11]It is a front view showing the first installation base used in the installation base system according to the second embodiment. [Figure 12] It is a perspective view showing the first installation base used in the installation base system according to the second embodiment. [Figure 13] It is a plan view schematically showing the first installation base used in the installation base system according to the third embodiment. [Figure 14] It is a side view schematically showing the installation base system and the jacket-type structure according to the fourth embodiment.

Mode for Carrying Out the Invention

[0009] [First Embodiment] Hereinafter, with reference to the drawings, a jacket structure system for an offshore wind turbine including an installation base system according to the first embodiment of the present disclosure and a moving method will be described. The jacket structure system for an offshore wind turbine includes a jacket structure for an offshore wind turbine having a plurality of legs. The jacket structure for an offshore wind turbine is one of the fixed foundations that support the offshore wind turbine. Among the fixed foundations that support the offshore wind turbine, in addition to the jacket structure for an offshore wind turbine, there is, for example, a monopile foundation for an offshore wind turbine described later. In the first embodiment, the jacket structure for an offshore wind turbine included in the jacket structure system for an offshore wind turbine may be in a completed state or in the middle of manufacture. The jacket structure system for an offshore wind turbine includes, for example, one or more jacket structures for offshore wind turbines. The jacket structure for an offshore wind turbine is installed on the sea by being connected to steel pipe piles driven into the seabed ground. The jacket structure for an offshore wind turbine supports an offshore wind turbine (not shown) on the sea. When the jacket structure system for an offshore wind turbine includes a plurality of jacket structures for offshore wind turbines, the structures or shapes of the respective jacket structures for offshore wind turbines may all be the same or may be different from each other.

[0010] Hereinafter, the configuration of the offshore wind turbine jacket structure 10, which is one of the offshore wind turbine jacket structures included in the installation base system 100 according to the first embodiment, will be described. FIG. 1 is a perspective view of the offshore wind turbine jacket structure system 1 including the installation base system 100 according to the first embodiment, showing the state on the yard Y. FIG. 2 is an enlarged view of part II shown in FIG. 1. FIG. 3 is a first side view showing the state where the leg 11 is installed on the first installation base S1. FIG. 4 is a second side view showing the state where the leg 11 is installed on the first installation base S1. FIG. 5 is an enlarged view of part V in FIG. 4. FIG. 6 is a plan view of FIG. 4. FIG. 7 is a front view showing the state where the leg 11 is sandwiched between the first transport trolley D1 and the second transport trolley D2. FIG. 8 is a plan view of FIG. 7. FIG. 9 is a perspective view of the offshore wind turbine jacket structure system 1 including the installation base system 100 according to the first embodiment, showing the state on the ship B. FIG. 10 is a plan view showing an example of the mounting position of the first installation base S1 on the ship B.

[0011] (Configuration of the offshore wind turbine jacket structure 10) As shown in FIG. 1, the offshore wind turbine jacket structure 10, which is an ocean structure, includes its base leg 11 (base), brace 12, and transition piece 13. Here, the base refers to the part installed (supported) on an installation base (described later). In the case of the offshore wind turbine jacket structure 10, the base may be a leg (for example, the lower part of the leg), a transition piece (described later), a brace, or a reinforcing member provided only for transporting the offshore wind turbine jacket structure 10. In the case of an offshore wind turbine monopile foundation (described later), the base may be its lower end or outer peripheral surface. In the case of a jacket-type structure 410 (described later), the base may be a leg (for example, the lower part of the leg), a brace, or a reinforcing member provided only for transporting the jacket-type structure 410. Leg 11 is a leg of the offshore wind turbine jacket structure 10. Leg 11 extends in the vertical direction. In the first embodiment, leg 11 is a cylindrical member. In other words, leg 11 is a hollow member. The lower part of leg 11 is connected to the upper end of a steel pipe pile (not shown). The upper end of leg 11 is connected to a transition piece 13. At this time, leg 11 may be bent or curved as appropriate to match the dimensions of the transition piece 13 connected to its upper end and the spacing between the steel pipe piles connected to its lower end. In the first embodiment, the offshore wind turbine jacket structure 10 includes a plurality of legs 11. Specifically, the offshore wind turbine jacket structure 10 has four legs 11.

[0012] In the first embodiment, the leg 11 and the steel pipe pile are connected, for example, by inserting the lower part of the leg 11 into the interior of the steel pipe pile from the upper end. After connection, the leg 11 and the steel pipe pile are fixed together, for example, by filling the space between the outer surface of the leg 11 and the inner surface of the steel pipe pile with grout. If grout flows into the interior of leg 11, it will cause extra grout to be needed to fix leg 11 to the steel pipe pile. To prevent this, a cover member 11C (see Figure 3) is provided at the bottom of the leg 11 to close the opening of the cylindrical leg 11 and prevent grout from flowing into the inside of the leg 11. This reduces the amount of grout required to fix the leg 11 to the steel pipe pile. Note that the cover member 11C is not required, and the connection method between the steel pipe pile and the leg 11 is not limited to this.

[0013] In the first embodiment, the diameter of the lid member 11C is larger than the diameter of the lower part of the leg 11. As a result, the lid member 11C forms a flange-like portion on the lower part of the leg 11. Hereinafter, this portion will be referred to as the flange portion 11f. The claw portion S1c of the first mounting base S1, which constitutes the mounting base system 100 described later, engages with the flange portion 11f. This prevents the leg 11 from lifting off the first mounting base S1.

[0014] When inserting leg 11 into the steel pipe pile, or when installing the lower part of leg 11 on the first mounting base S1, it is necessary to appropriately align the lower end of leg 11. To facilitate this alignment, a cross-shaped member 11G is provided at the lower end of leg 11. The cross-shaped member 11G functions as a guide to lead the lower end of leg 11 to the upper end of the steel pipe pile, or to the hole S1h (see Figure 6) of the first mounting base S1, which will be described later. The cross-shaped member 11G is formed in a cross shape when viewed along the axial direction of the lower end of leg 11. The cross-shaped member 11G is formed, for example, by arranging multiple plate-shaped members in a cross shape. Note that a member with a shape other than a cross may be used instead of the cross-shaped member 11G.

[0015] Preferably, the cross-shaped member 11G has a shape that has a vertex 11Gt projecting downward at the radial center of the leg 11, as shown in Figures 3 and 4. This allows the central axis of the leg 11 to be guided to substantially coincide with the central axis of the steel pipe pile, for example, when aligning the leg 11 with the steel pipe pile, after the vertex 11Gt of the cross-shaped member 11G is inserted into the steel pipe pile, as the leg 11 moves downward, the cross-shaped member 11G continues to contact the steel pipe pile. In order to provide a vertex 11Gt on the cross-shaped member 11G, it is preferable that each of the plate-shaped members forming the cross-shaped member 11G be, for example, trapezoidal or triangular in shape. Furthermore, in order to facilitate alignment between the leg 11 and the steel pipe pile or the first installation base S1 using the cross-shaped member 11G, it is preferable that the dimension of the cross-shaped member 11G in the direction perpendicular to the axial direction of the lower end of the leg 11 is, for example, about the same as the diameter of the cover member 11C. Alternatively, the dimension of the cross-shaped member 11G in the direction perpendicular to the axial direction of the lower end of the leg 11 may be larger than the diameter of the cover member 11C, as shown in Figure 6, as long as the cross-shaped member 11G can be accommodated inside the steel pipe pile. Note that the cross-shaped member 11G may be omitted.

[0016] The brace 12 connects the four legs 11 to each other along the circumferential direction of the offshore wind turbine jacket structure 10. The brace 12 is joined to the legs 11, for example, by welding. In this way, the brace 12 reinforces the structure consisting of the four legs 11. Note that the number of legs 11 in the offshore wind turbine jacket structure 10 is not limited to four. If there are more than four legs, the brace will not directly connect to any legs other than adjacent ones. The transition piece 13 is the part of the offshore wind turbine jacket structure 10 to which the offshore wind turbine is connected. Specifically, the lower end of the offshore wind turbine tower is connected to the transition piece 13. The transition piece 13 is also supported by the four legs mentioned above. With the above configuration, the offshore wind turbine jacket structure 10 supports the offshore wind turbine.

[0017] (Manufacturing and transportation of jacket structures for offshore wind turbines) The offshore wind turbine jacket structure 10 according to the first embodiment is manufactured by assembling the aforementioned components in a land-based yard (factory), and then transported to the offshore installation site. It is then installed offshore by connecting it to steel pipe piles that have been pre-driven into the seabed. The offshore wind turbine jacket structure 10 is also transported on land by transport trolley D, as shown in Figures 1 and 2, according to each stage of the manufacturing process. In addition, instead of connecting the offshore wind turbine jacket structure 10 to steel pipe piles that have been pre-driven into the seabed, it may be installed before the steel pipe piles are driven, and then the steel pipe piles may be driven into the seabed afterward so that they can be connected to the offshore wind turbine jacket structure 10 that has been installed in this manner.

[0018] The following describes the manufacturing and transportation aspects of the offshore wind turbine jacket structure 10 according to the first embodiment. In other words, for example, when manufacturing the offshore wind turbine jacket structure 10, each of the multiple legs 11 is installed on the first mounting base S1 which constitutes the mounting base system 100 according to the first embodiment, as shown in Figure 3 or Figure 4. The offshore wind turbine jacket structure 10 under construction is transported by moving the first mounting base S1 on which the legs 11 are installed using a transport trolley D, as shown in Figures 1 and 2. At this time, the first mounting base S1 and the transport trolley D are connected by a horizontal member H (see Figure 7). This makes it possible to move the first mounting base S1 and the legs 11 using the transport trolley D.

[0019] (1st installation stand) For example, as shown in Figure 3 or Figure 4, the first mounting base S1 comprises a first leg portion S1a, a first beam portion S1b, a claw portion S1c, and a contact member S1d. The first leg portion S1a is the part that contacts the ground. The first leg portion S1a extends horizontally along the ground, for example. At this time, the first leg portion S1a extends along the direction of travel when the offshore wind turbine jacket structure 10 is being transported, for example. This allows the transport trolley D to be positioned along the longitudinal direction of the first leg portion S1a. For the first leg portion S1a, for example, a known structural steel such as an H-beam or I-beam is used. In this case, for example, the web portion of the first leg portion S1a is positioned perpendicular to the ground, and the flange portion is positioned in contact with the ground. Two first leg portions S1a are provided on the first mounting base S1, approximately parallel to each other. In the first embodiment, approximately parallel means that the relative angle is 5° or less. This ensures that when the leg 11 is installed on the first mounting base S1, the lower part of the leg 11 is positioned between the two first leg portions S1a. Each of the two first legs S1a has a joint S1a1 to which a horizontal member H (described later) can be pin-connected, as shown in Figures 3 to 6. The joint S1a1 is provided on the upper part of each of the first legs S1a. Two joint S1a1 are provided for each of the two first legs S1a.

[0020] The first beam section S1b connects the two first leg sections S1a described above. That is, the first beam section S1b extends in a direction perpendicular to the direction in which the first leg sections S1a extend, while remaining parallel to the ground. Both ends of the first beam section S1b are joined to the two first leg sections S1a, which are provided substantially parallel to each other. For example, known H-beams or I-beams can be used for the first beam section S1b. In this case, for example, the first beam section S1b is positioned so that the web portion is perpendicular to the ground and the flange portion is in contact with the ground. Two first beam sections S1b are provided substantially parallel to each other on the first mounting base S1. This ensures that when the leg 11 is installed on the first mounting base S1, the lower part of the leg 11 is positioned between the two first beam sections S1b. In the first mounting base S1, for example, two first leg sections S1a and two first beam sections S1b are connected in a rectangular frame shape to form the main frame F of the first mounting base S1.

[0021] As described above, when the leg 11 is installed on the first mounting base S1, the lower part of the leg 11 is located between the two first leg portions S1a and the two first beam portions S1b. In other words, the first mounting base S1 has a hole S1h formed by the two first leg portions S1a and the two first beam portions S1b, and the leg 11 is installed on the first mounting base S1 such that the lower part of the leg 11 is inserted into the hole S1h. At this time, a cross-shaped member 11G is inserted into the hole S1h, as shown in Figures 3 and 4. In this way, the cross-shaped member 11G functions as a guide when installing the leg 11 on the first mounting base S1. In the first embodiment, the lower end of the cross-shaped member 11G inserted into the hole S1h does not come into contact with the ground and the first mounting base S1. In other words, in the first embodiment, as shown in Figure 4, the height h1 of the first leg portion S1a and the first beam portion S1b is greater than or equal to the height h2 of the cross-shaped member 11G. Also, as shown in Figure 6, the size of the hole S1h when viewed from above is such that the cross-shaped member 11G can be accommodated without interfering with the hole S1h. This prevents loads such as the weight of the leg 11 from acting on the cross-shaped member 11G.

[0022] When the cross-shaped member 11G of the leg 11 is inserted into the hole S1h of the first mounting base S1, the cover member 11C of the leg 11 abuts against the upper surfaces of the first leg portion S1a and the first beam portion S1b of the first mounting base S1, as shown in Figures 3 to 6. This installs the leg 11 on the first mounting base S1. At this time, it is preferable that the first leg portion S1a and the first beam portion S1b are at the same height in order to apply the load of the leg 11 evenly by making the contact area of ​​the cover member 11C of the leg 11 equal to each of the two first leg portions S1a and the two first beam portions S1b. Furthermore, it is preferable that the hole S1h formed by the two first leg portions S1a and the two first beam portions S1b is square in shape, with the length of one side being smaller than the diameter of the cover member 11C, and being square in a size that can accommodate the cross-shaped member 11G. Furthermore, it is preferable that the length of one side of the hole S1h is such that the cross-shaped member 11G can be accommodated without interfering with the hole S1h. That is, for example, even if the dimension of the lower end of the leg 11 of the cross-shaped member 11G in the direction perpendicular to the axial direction is greater than the diameter of the lid member 11C, it is preferable that the length is such that the cross-shaped member 11G can be accommodated by arranging the plates forming the cross-shaped member 11G in a plan view along the diagonals of the hole S1h, as shown in Figure 6.

[0023] The claw portion S1c is a plate-shaped member that is attached to the first leg portion S1a or the first beam portion S1b by welding or the like. The claw portion S1c is positioned upright on the upper surface of the first leg portion S1a or the first beam portion S1b, with the edge of the plate surface joined to the first leg portion S1a or the first beam portion S1b. This makes it possible to reduce the welding surface area of ​​the claw portion S1c to the first leg portion S1a or the first beam portion S1b, thereby improving the workability of welding. As shown in Figure 5, the claw portion S1c is provided with a notch S1c1. The notch S1c1 comes into contact with the cover member 11C of the leg 11, thereby engaging with the cover member 11C of the leg 11. In this way, the claw portion S1c prevents the leg 11, which is installed on the first mounting base S1, from lifting off the first mounting base S1.

[0024] As shown in Figure 5, the notch S1c1 is provided by cutting out the end of the portion where the claw portion S1c and the first leg portion S1a or the first beam portion S1b come into contact. The dimension d1 of the notch S1c1 in the direction along the upper surface of the first leg portion S1a or the first beam portion S1b is such that it can engage with the flange portion 11f formed by the cover member 11C at the lower part of the leg 11. The dimension d2 of the notch S1c1 in the direction perpendicular to the upper surface of the first leg portion S1a or the first beam portion S1b is equal to the thickness of the cover member 11C. Here, as described above, a flange portion 11f is formed on the lower part of the leg 11 by a cover member 11C which has a larger diameter than the lower part of the leg 11. Therefore, as shown in Figure 3, after the lower part of the leg 11 is inserted into the hole S1h of the first mounting base S1, as shown in Figure 4, when the claw portion S1c is attached to the upper surfaces of the first leg portion S1a and the first beam portion S1b, the notch S1c1 of the claw portion S1c engages with the cover member 11C. As a result, the claw portion S1c prevents the leg 11 installed on the first mounting base S1 from lifting off the first mounting base S1. The claw portions S1c are provided evenly on each of the two first leg portions S1a and the two first beam portions S1b, for example. That is, as shown in Figure 6, for example, two claw portions S1c are provided on each of the contact surfaces A between the cover member 11C of the leg 11 and the first leg portion S1a or the first beam portion S1b, near both ends in the longitudinal direction of the contact surface. It is preferable that this ensures that the claw portions S1c reliably prevent the leg 11 from lifting off the first mounting base S1.

[0025] As shown in Figure 6, the contact member S1d contacts the cover member 11C to determine the horizontal position of the lower part of the leg 11 relative to the first mounting base S1. In the first embodiment, the contact member S1d is a plate-shaped member that is attached to each of the first leg portion S1a and the first beam portion S1b by welding or the like. The following description will focus on the contact member S1d provided on one of the two first leg portions S1a, but it is similarly provided on the other first leg portion S1a and the two first beam portions S1b.

[0026] The contact member S1d is provided in one of the first leg portions S1a, in a portion corresponding to the middle of one side of the hole S1h. The contact member S1d includes, for example, a contact plate S1d1 that contacts the lid member 11C, and a reinforcing plate S1d2 that reinforces the contact plate S1d1. The contact plate S1d1 is positioned upright on the upper surface of the first leg portion S1a, with the edge of the plate surface joined to the first leg portion S1a. Two contact plates S1d1 are placed on the upper surface of the first leg portion S1a with a gap between them. The two contact plates S1d1 have the same shape as each other. Preferably, the edge of the contact plate S1d1 that faces the hole S1h has an inclined portion S1ds that slopes away from the hole S1h as it moves from bottom to top, as shown in Figure 3, for example. This allows the lid member 11C, which is in contact with the inclined portion S1ds, to be guided towards the center of the hole S1h as it moves downward when the leg 11 is installed on the first mounting base S1. As shown in Figures 3 and 6, the reinforcing plate S1d2 is provided to connect the edges of the two contact plates S1d1 that are aligned vertically along the legs 11, that is, the edges of the horizontally facing parts that do not face the holes S1h. In other words, when the reinforcing plate S1d2 is standing upright on the upper surface of the first leg S1a, the edges of the plate surface are joined to the upper surface of the first leg S1a and to the edges of the two contact plates S1d1 that are aligned vertically and do not face the holes S1h. In this way, the reinforcing plate S1d2 prevents the contact plate S1d1, which is erected on the upper surface of the first leg portion S1a, from falling over or deforming due to contact with the lid member 11C or the like. The contact member S1d is not limited to the configuration described above; for example, it may be a block-shaped member having a portion corresponding to the inclined portion S1ds.

[0027] (Transport cart) As shown in Figure 2, the transport trolley D transports the offshore wind turbine jacket structure 10. The transport trolley D comprises a loading platform Dc on which the object to be transported can be placed, and a plurality of wheels Dt for moving the loading platform Dc. A known dolly is preferably used as the transport trolley D. The loading platform Dc is movable in the vertical direction. The transport trolleys D are positioned at each of the multiple legs 11 of the offshore wind turbine jacket structure 10. Each of the transport trolleys D positioned at each leg 11 moves simultaneously in the same direction and at the same speed, for example, when the offshore wind turbine jacket structure 10 is moving in a straight line. Alternatively, when the direction of travel of the offshore wind turbine jacket structure 10 is changed, the speed of each transport trolley D is changed as appropriate. In this way, the transport trolleys D transport the legs 11 and the offshore wind turbine jacket structure 10.

[0028] For example, when transporting the offshore wind turbine jacket structure 10, the legs 11 are placed on the first transport trolley D1 and the second transport trolley D2, respectively. At this time, the legs 11 are sandwiched between the first transport trolley D1 and the second transport trolley D2. In other words, one leg 11 is transported by two transport trolleys D. In the first embodiment, the first transport trolley D1 and the second transport trolley D2 have the same configuration. Hereinafter, in the first embodiment, when the first transport trolley D1 and the second transport trolley D2 are not distinguished, they will be referred to as transport trolley D. It is also possible to transport the offshore wind turbine jacket structure 10 lying down on the transport trolley. In this case, the base of the offshore wind turbine jacket structure 10 that is installed (supported) on the transport trolley can be made of something other than a leg, such as a brace or a transition piece of the offshore wind turbine jacket structure 10. Alternatively, the base in this case can be a reinforcing member provided solely for the purpose of transporting the offshore wind turbine jacket structure 10.

[0029] For example, when the leg 11 is transported by the transport trolley D, the leg 11 is transported while installed on the first mounting base S1. In the first embodiment, the transport trolley D transports the leg 11 by moving the first mounting base S1. In the first embodiment, when the first mounting base S1 is moved by the transport trolley D, one first mounting base S1 is moved by two transport trolleys D. That is, the first mounting base S1 is locked to and sandwiched between the first transport trolley D1 and the second transport trolley D2. At this time, the transport trolley D is positioned along the longitudinal direction of the first leg portion S1a of the first mounting base S1. This makes the first mounting base S1 movable in the direction in which the first leg portion S1a extends. In the first embodiment, the transport trolley D is secured to the first mounting base S1 via the horizontal member H described below.

[0030] (horizontal material) The horizontal member H locks the transport trolley D and the first installation base S1. The horizontal member H is attached to the first installation base S1 when the offshore wind turbine jacket structure 10 is being transported, that is, when the first installation base S1 is being moved by the transport trolley D. The lower surfaces of the first horizontal member H1 and the second horizontal member H2 are in contact with the upper surfaces of the first transport trolley D1 and the second transport trolley D2. In other words, the transport trolley D is positioned so that the loading platform Dc is located below the horizontal member H attached to the first installation base S1, and by moving the loading platform Dc upward, the horizontal member H is jacked up, i.e., lifted. In this way, the transport trolley D lifts the first installation base S1 via the horizontal member H. In the first embodiment, locking the transport trolley D and the first installation base S1 means the state in which the first installation base S1 is lifted by the transport trolley D. Furthermore, in the first embodiment, when we say that the legs 11 are placed on the first transport trolley D1 and the second transport trolley D2, we mean that the first mounting base S1 on which the legs 11 are installed is placed on the first transport trolley D1 and the second transport trolley D2.

[0031] When the transport trolley D and the first mounting base S1 are locked together, a first horizontal member H1 and a second horizontal member H2 are provided on the upper part of the first mounting base S1. The first horizontal member H1 and the second horizontal member H2 have the same configuration. The first horizontal member H1 and the second horizontal member H2 are members that extend along the horizontal direction. At this time, the first horizontal member H1 and the second horizontal member H2 each extend in a direction perpendicular to the direction in which the first leg portion S1a extends. As shown in Figure 7, the first horizontal member H1 and the second horizontal member H2 are removably pin-connected to the first mounting base S1 by pins Pi. Specifically, as shown in Figure 7, the first horizontal member H1 and the second horizontal member H2 are pin-connected to the respective joints S1a1 provided on the two first legs S1a. At this time, the first horizontal member H1 is positioned on the opposite side of the second horizontal member H2, with the pipe axis of the leg 11 in between. The position where the first horizontal member H1 and the first mounting base S1 are pin-connected is symmetrical with respect to the leg 11 to the position where the second horizontal member H2 and the first mounting base S1 are pin-connected. This arrangement allows the first mounting base S1 to be stably lifted by the transport trolley D.

[0032] (Method for moving jacket structures for offshore wind turbines) Next, a method for transporting the offshore wind turbine jacket structure according to the first embodiment will be described. That is, in the first embodiment, the offshore wind turbine jacket structure 10 is transported by moving a plurality of legs 11 using the above-described configurations. At this time, the legs 11 are placed on the first transport trolley D1 and the second transport trolley D2, along with the connected first installation base S1, and jacked up. At this time, the legs 11 included in the plurality of legs are sandwiched between the first transport trolley D1 and the second transport trolley D2. This makes it possible to transport the entire offshore wind turbine jacket structure 10 stably by stably transporting each of the plurality of legs 11.

[0033] When moving the offshore wind turbine jacket structure 10 assembled in yard Y to the transport ship B, each of the multiple legs 11, along with the first mounting base S1, is jacked up on the ground Y1 of yard Y using the first transport trolley D1 and the second transport trolley D2 via the first horizontal member H1 and the second horizontal member H2, and the entire offshore wind turbine jacket structure 10 is moved from the state shown in Figure 1 to the deck B1 of ship B as shown in Figure 9 by running the first transport trolley D1 and the second transport trolley D2. At this time, a transfer plate (not shown) on which each of the first transport trolley D1 and each of the second transport trolley D2 can travel may be appropriately laid between the ground Y1 of yard Y and the deck B1 of ship B. In Figures 1 and 9, the ship B on which the offshore wind turbine jacket structure 10 is loaded is shown as a barge towed by a tugboat; however, the ship B on which the offshore wind turbine jacket structure 10 is loaded may be a self-propelled vessel other than a barge.

[0034] Then, the offshore wind turbine jacket structure 10, which has been moved onto the deck B1 of ship B, is positioned at a predetermined mounting location. That is, each of the multiple legs 11 is transported on the deck B1 of ship B, together with the first mounting base S1, the first horizontal member H1, and the second horizontal member H2, using the first transport trolley D1 and the second transport trolley D2, and positioned vertically above the predetermined mounting location. Then, each of the multiple legs 11 is simultaneously jacked down using the first transport trolley D1 and the second transport trolley D2. As a result, the first mounting base S1 on which each of the multiple legs 11 is installed is placed at the predetermined mounting location on the deck B1. At that time, each of the first mounting bases S1 is positioned so as to straddle at least two or more of the deck support members that support the deck B1 from below, namely the beams and walls. That is, each of the first mounting bases S1 is positioned such that it straddles at least two beams, at least two walls, or at least one beam and at least one wall. The beams that serve as deck support members include transbeams that extend in the direction connecting one end of the ship B to the other end and support the deck B1 from below, and longitudinal members (longitudinal beams, longitudinal girders) that extend in the direction connecting the bow and stern of the ship B and support the deck B1 from below. The walls that serve as deck support members include transbulkheads that extend in the direction connecting one end of the ship B to the other end and support the deck B1 from below, and longitudinal bulkheads that extend in the direction connecting the bow and stern of the ship B and support the deck B1 from below. Each of the first mounting bases S1 is placed on the ship B such that, for example as shown in Figure 10(a), it straddles either one transbeam B2 which extends in the direction connecting one end side of the ship B and the other end side and supports the deck B1 from below, and either another transbeam B2 which extends in the direction connecting one end side of the ship B and the other end side and supports the deck B1 from below, or it straddles either one transbeam B2 and a transbulkhead which extends in the direction connecting one end side of the ship B and the other end side and supports the deck B1 from below.Each first mounting base S1 may, for example, straddle at least two transbeams B2, or at least one transbeam B2 and one transbulkhead. Therefore, each first mounting base S1 may, for example, straddle two transbeams B2 and one transbulkhead, or one transbeam B2 and two transbulkheads, or two transbeams B2 and two transbulkheads. All first mounting bases S1 placed in predetermined mounting positions on deck B1 are then appropriately fixed to deck B1. Alternatively, as shown in Figure 10(b), the first mounting base S1 may be placed on the ship B so as to straddle either one transbeam B2 and either one of the longitudinal members (longitudinal beam or longitudinal girder) B3 that extends in the direction connecting the bow and stern of the ship B and supports the deck B1 from below, or a longitudinal bulkhead that extends in the direction connecting the bow and stern of the ship B and supports the deck B1 from below. Alternatively, the first mounting base S1 may be placed on the ship B so as to straddle at least two longitudinal members. Alternatively, the first mounting base S1 may be placed on the ship B so as to straddle at least two longitudinal bulkheads.

[0035] The above describes the movement steps for moving the offshore wind turbine jacket structure 10, which is an offshore structure, onto ship B, together with the first installation platform S1 which was being used for yard Y. Furthermore, when the offshore wind turbine jacket structure 10 is jacked down on ship B, the first transport trolley D1 and the second transport trolley D2 will move, for example, by traveling from ship B towards yard Y. Also, when the first transport trolley D1 and the second transport trolley D2 jack down the offshore wind turbine jacket structure 10 on ship B, the first horizontal member H1 and the second horizontal member H2 will be removed from the first mounting base S1, for example, by removing the pin Pi.

[0036] As described above, with the offshore wind turbine jacket structure 10 installed on the ship B via the first mounting base S1, each of the first mounting bases S1 is appropriately fixed to the deck B1 of the ship B. The ship B, with the offshore wind turbine jacket structure 10 loaded via the first mounting bases S1 in this state, sails to, for example, the installation site. At the installation site, the offshore wind turbine jacket structure 10 is removed from all of the first mounting bases S1, and is then installed offshore by, for example, being lifted and connected to steel pipe piles driven into the seabed.

[0037] As described above, the installation platform system 100 of the first embodiment on which the offshore wind turbine jacket structure 10 is installed includes a first installation platform S1 on which the legs 11, which are the base of the offshore wind turbine jacket structure 10 and are bottom-fixed foundations that support the offshore wind turbine, are installed.

[0038] Furthermore, in this mounting system 100, the first mounting platform S1 serves as both a yard mounting platform placed in yard Y and a shipboard mounting platform placed on ship B. In other words, this mounting system 100 includes the first mounting platform S1, which is a yard mounting platform placed in yard Y and on which the legs 11, which are the base of the offshore wind turbine jacket structure 10, are installed. In addition, this mounting system 100 includes the first mounting platform S1, which is a shipboard mounting platform placed on ship B and on which the legs 11, which are the base of the offshore wind turbine jacket structure 10, are installed.

[0039] Furthermore, the mounting platform system 100 is such that the first mounting platform S1 for yard use and the first mounting platform S1 for ship use are the same. Therefore, the mounting platform system 100 shares a common frame F for the first mounting platform S1 for yard use, which includes two first legs S1a and two first beams S1b, and a common frame F for the first mounting platform S1 for ship use, which includes two first legs S1a and two first beams S1b.

[0040] Furthermore, the first mounting platform S1 of this mounting platform system 100, which serves as both a yard mounting platform and a shipboard mounting platform, is made of steel. Furthermore, in this mounting platform system 100, the first mounting platform S1, which serves as both a yard mounting platform and a shipboard mounting platform, uses shaped steel such as H-beams or I-beams for at least the first leg portion S1a.

[0041] Furthermore, in this mounting platform system 100, the first mounting platform S1, which serves as the mounting platform for the ship, is placed on the ship B such that it spans at least two of the deck support members that support the deck B1 from below, namely, the beams and walls. In other words, the first mounting platform S1 is placed on the ship B such that it spans at least two beams, at least two walls, or at least one beam and at least one wall.

[0042] As described above, the mounting platform system 100 according to the first embodiment includes a first mounting platform S1, which is a yard mounting platform placed on yard Y and on which the legs 11, which are the base of the offshore wind turbine jacket structure 10, are installed. Furthermore, this mounting platform system 100 also includes a first mounting platform S1, which is a shipboard mounting platform placed on ship B and on which the legs 11, which are the base of the offshore wind turbine jacket structure 10, are installed. Therefore, this mounting platform system 100 makes it possible to install the offshore wind turbine jacket structure 10, which is an offshore structure, on both yard Y and ship B.

[0043] Furthermore, in this mounting system 100, the legs 11, which are the base of the offshore wind turbine jacket structure 10, are installed, and the first mounting platform S1, which is a yard mounting platform placed in yard Y, is made of steel. As a result, the weight of the first mounting platform S1, which is a yard mounting platform, is lighter in this mounting system 100 compared to when the first mounting platform S1, which is a yard mounting platform, is made of steel compared to when it is made of concrete.

[0044] Furthermore, in this mounting platform system 100, the first mounting platform S1 for yard use and the first mounting platform S1 for ship use are the same, i.e., identical. Therefore, this mounting platform system 100 allows the same first mounting platform S1 to be used on both yard Y and ship B. As a result, the number of first mounting platforms S1 used can be reduced, and the transfer of the offshore wind turbine jacket structure 10 from the yard mounting platform to the ship use platform becomes unnecessary, thus achieving significant cost reductions. Note that the first mounting platform S1 for yard use and the first mounting platform S1 for ship use do not necessarily have to be the same.

[0045] Furthermore, in this mounting platform system 100, the first mounting platform S1, which serves as both a yard mounting platform and a shipboard mounting platform, is made of steel. Because it can be used for both purposes, the first mounting platform S1, which serves as both a yard mounting platform and a shipboard mounting platform, is easy to manufacture, thus reducing costs. Note that the first mounting platform S1, which serves as both a yard mounting platform and a shipboard mounting platform, does not necessarily have to be made of steel.

[0046] Furthermore, in this mounting platform system 100, structural steel is used for the first mounting platform S1, which serves as both a yard mounting platform and a shipboard mounting platform. Therefore, in this mounting platform system 100, the manufacturing of the first mounting platform S1, which serves as both a yard mounting platform and a shipboard mounting platform, becomes even easier, and further cost reductions can be achieved. However, structural steel is not required to be used for the first mounting platform S1, which serves as both a yard mounting platform and a shipboard mounting platform.

[0047] Furthermore, in this mounting platform system 100, the first mounting platform S1, which serves as the mounting platform for the ship, is placed on the ship B such that it straddles at least two of the deck support members that support the deck B1 from below, namely the beams and walls. In other words, the first mounting platform S1 is placed on the ship B such that it straddles at least two beams, at least two walls, or at least one beam and at least one wall. Therefore, this mounting platform system 100 can reliably place heavy objects, such as the jacket structure 10 for the offshore wind turbine which is a jacket-type foundation, on the ship B even if they are heavy objects. Note that the first mounting platform S1, which serves as the mounting platform for the ship, does not necessarily have to straddle one deck support member and any other deck support member on the ship B.

[0048] Furthermore, the moving method according to the first embodiment includes a moving step of moving the offshore wind turbine jacket structure 10, which is an offshore structure, onto the ship B together with the first mounting base S1 that was used for yard Y. In this moving method, since the yard mounting base and the shipboard mounting base are the same first mounting base S1, it is not necessary to transfer the offshore wind turbine jacket structure 10 from the yard mounting base to the shipboard mounting base when moving the offshore wind turbine jacket structure 10 from yard Y to ship B. Moreover, since the first mounting base S1, which is the yard mounting base, is made of steel, the first mounting base S1, which is the yard mounting base, is relatively light, making it possible to easily move the offshore wind turbine jacket structure 10 together with the first mounting base S1, which is the yard mounting base. This relative lightness of the first mounting base S1 is more effective when moving offshore structures with a crane.

[0049] The mounting base system 100 and the movement method according to the first embodiment described above can also be modified as shown in the following variations 1-1 to 1-5. Furthermore, variations 1-1 to 1-5 can be combined as appropriate.

[0050] <Variation 1-1> In the first embodiment, the installation platform system 100 and moving method described a case in which the offshore wind turbine jacket structure 10, together with the first installation platform S1, is moved from yard Y to ship B using a transport trolley D, and the offshore wind turbine jacket structure 10 is then placed and fixed on ship B via the same first installation platform S1. In contrast, in the installation platform system and moving method according to Modification 1-1, the offshore wind turbine jacket structure 10, together with the first installation platform S1, is moved from yard Y to ship B using a skid beam (not shown), and the offshore wind turbine jacket structure 10 is then placed and fixed on ship B via the same first installation platform S1.

[0051] In this case, for example, a laying step is performed in which the skid beam is laid from yard Y to ship B. In the laying step, the skid beam may be laid from yard Y to ship B below the first horizontal member H1 and the second horizontal member H2 of the first mounting base S1, which is provided in yard Y and on which each of the multiple legs 11 of the offshore wind turbine jacket structure 10 is placed. After that, a jacking-up step is performed in which the multiple legs 11 of the offshore wind turbine jacket structure 10, together with the first mounting base S1 on which each is placed, are jacked up via the first horizontal member H1 and the second horizontal member H2 to jack up the entire offshore wind turbine jacket structure 10. After that, a mounting step is performed on the skid beam in which the multiple legs 11 of the offshore wind turbine jacket structure 10, together with the first mounting base S1 on which each is placed, are jacked down via the first horizontal member H1 and the second horizontal member H2. Then, the multiple legs 11 of the offshore wind turbine jacket structure 10, along with the first mounting base S1 on which each of them is placed, are mounted on the skid beam via the first horizontal member H1 and the second horizontal member H2. In this state, the multiple legs 11 of the offshore wind turbine jacket structure 10, along with the first mounting base S1 on which each of them is placed, are slid along the skid beam to move the offshore wind turbine jacket structure 10, along with the multiple first mounting bases S1 on which it is placed, in a transfer step that moves it onto the ship B. In this way, the offshore wind turbine jacket structure 10, along with the first mounting base S1, is positioned vertically above a predetermined mounting position similar to that of the first embodiment. Then, the offshore wind turbine jacket structure 10, along with the first mounting base S1, is jacked up via the first horizontal member H1 and the second horizontal member H2. Subsequently, the skid beam is removed, and the multiple legs 11 of the offshore wind turbine jacket structure 10, along with the first mounting base S1 on which each is placed, are jacked down via the first horizontal member H1 and the second horizontal member H2 to be placed in a predetermined mounting position similar to that of the first embodiment. Then, the first mounting base S1 is fixed to the ship B. Here, the movement of the offshore wind turbine jacket structure 10 on the skid beam may be by being pushed from the yard Y side to the ship B side, or by being pulled from the yard Y side to the ship B side. Note that the skid beam may not be removed from the ship B.For example, the offshore wind turbine jacket structure 10 is placed on a skid beam on a ship (barge) while lying on its side. Then, with the jacket structure still in place, the ship is moved to a location with deep water, and then the offshore wind turbine jacket structure 10 is installed using the skid beam by launching (a construction method in which the barge is tilted and slid into the sea).

[0052] The above describes the moving step of moving the offshore wind turbine jacket structure 10, which is an offshore structure, onto ship B together with the first installation platform S1, which was used for yard Y, using a skid beam. In this case, the moving step includes a jacking-up step in which the offshore wind turbine jacket structure 10, which is an offshore structure, is jacked up together with the first installation platform S1, which is an installation platform for the yard, and an installation step in which the offshore wind turbine jacket structure 10 and the first installation platform S1, which is an installation platform for the yard, which have been jacked up in the jacking-up step, are placed on the skid beam.

[0053] In this modified version 1-1, the offshore wind turbine jacket structure 10, which is an offshore structure, and the first mounting base S1, which is a mounting base for the yard, can be moved more reliably from yard Y to ship B using a skid beam. This allows the offshore wind turbine jacket structure 10 to be moved more reliably from yard Y to ship B.

[0054] <Variation 1-2> In addition to moving the offshore wind turbine jacket structure 10 together with the first mounting base S1 from yard Y to ship B using a transport trolley D as in the first embodiment, or moving the offshore wind turbine jacket structure 10 together with the first mounting base S1 from yard Y to ship B using a skid beam (not shown) as in Modification 1-1, it is also possible, as in Modification 1-2, to move the offshore wind turbine jacket structure 10 together with the first mounting base S1 from yard Y to ship B using a crane (not shown), and then place the offshore wind turbine jacket structure 10 on ship B at a predetermined mounting position similar to that in the first embodiment via the same first mounting base S1.

[0055] <Variation 1-3> The installation platform system and moving method according to the first embodiment, modified example 1-1, and modified example 1-2 describe a case in which the offshore wind turbine jacket structure 10 is moved from yard Y to ship B together with the first installation platform S1, and the offshore wind turbine jacket structure 10 is then placed and fixed on ship B via the same first installation platform S1. In contrast, the installation platform system and moving method according to modified example 1-3 has a common configuration with the first installation platform S1 which is a yard installation platform, but uses a different first installation platform S1 as an onboard installation platform. Here, "configuration" means "shape, framework, material, etc."

[0056] In this case, the method of movement includes a placement step and an installation step. The placement step is to place the first installation platform S1, which is an onboard installation platform, on the ship B. The installation step is to transfer the offshore wind turbine jacket structure 10 from the first installation platform S1, which is an onboard installation platform, to the first installation platform S1, which was placed on the ship B in the placement step, and install it.

[0057] In the placement step, it is preferable that the first mounting platform S1, which is a mounting platform for use on the ship, is placed on the ship B so as to be the same as in the first embodiment, that it straddles at least two or more of the beams and walls, which are deck support members that support the deck B1 from below. That is, it is preferable that the first mounting platform S1 is placed on the ship B so as to straddle at least two beams, or at least two walls, or at least one beam and at least one wall.

[0058] In the installation step, for example, at yard Y, the offshore wind turbine jacket structure 10 is removed from the first installation platform S1, which is a yard installation platform, and the offshore wind turbine jacket structure 10 is transported onto ship B using a crane, transport trolley, skid beam, etc. Then, the legs 11 of the offshore wind turbine jacket structure 10 are installed on each of the first installation platforms S1, which are shipboard installation platforms that were previously installed on ship B in the deployment step, using a crane, etc. Alternatively, for example, the offshore wind turbine jacket structure 10 together with the first installation platform S1, which is a yard installation platform, is moved from yard Y onto ship B using a crane, transport trolley D, skid beam, etc. On ship B, the offshore wind turbine jacket structure 10 is removed from the first installation platform S1, which is a yard installation platform, and the offshore wind turbine jacket structure 10 is moved using a crane, etc., and the legs 11 are installed on each of the first installation platforms S1, which are shipboard installation platforms that were previously installed on ship B in the deployment step. Here, "installation" when installing the first installation stand S1 or the other installation stand in a designated location includes simply placing the first installation stand S1 or the other installation stand in the designated location (without fixing it in place).

[0059] Even with this configuration, it is possible to use a common first mounting platform S1 on both yard Y and ship B, thus reducing costs compared to using mounting platforms with different configurations on yard Y and ship B. Furthermore, it is not necessary to use a separate first mounting platform S1, which has the same configuration as the first mounting platform S1 for the yard, as the mounting platform for the ship.

[0060] <Variation 1-4> The installation platform system and movement method according to Modification 1-3 were explained using the example of a case where a first installation platform S1, which is a yard installation platform, and a second installation platform S1 (not shown), which is a shipboard installation platform, are provided separately with a common configuration. In contrast, in the installation platform system and movement method according to Modification 1-4, the first installation platform S1, which is a yard installation platform, and the second installation platform S1 (not shown), which is a shipboard installation platform, have different configurations. It is preferable that the second installation platform S1 (not shown), which is a shipboard installation platform, is also made of steel.

[0061] For example, if the first mounting platform S1, which is a yard mounting platform, is unsuitable for use as a shipboard mounting platform, a second mounting platform different from the first mounting platform S1 is used as the shipboard mounting platform. In this case, it is preferable to share the frame F, which includes, for example, two first leg sections S1a and two first beam sections S1b, between the first mounting platform S1 and the second mounting platform. By sharing the frame F of the first mounting platform S1, which is a yard mounting platform, and the frame F of the second mounting platform, which is a shipboard mounting platform, it becomes possible to simplify the manufacturing and handling of each. Furthermore, by sharing the frame F between the first mounting platform S1 and the second mounting platform, structural steel is also used for the second mounting platform, which is a shipboard mounting platform, making it easier to manufacture both the first mounting platform S1, which is a yard mounting platform, and the second mounting platform, which is a shipboard mounting platform.

[0062] In this case, the method of movement includes a placement step and an installation step. The placement step is to place the second installation platform, which is an onboard installation platform, on ship B. The installation step is to transfer the offshore wind turbine jacket structure 10 from the first installation platform S1, which is a yard installation platform, onto the second installation platform that was placed on ship B in the placement step, and install it.

[0063] In the placement step, it is preferable that the second mounting platform, which is a mounting platform for use on the ship, is placed on the ship B so as to straddle at least two or more of the deck support members that support the deck B1 from below, namely the beams and walls. In other words, it is preferable that the second mounting platform is placed on the ship B so as to straddle at least two beams, or at least two walls, or at least one beam and at least one wall.

[0064] In the installation step, for example, at yard Y, the offshore wind turbine jacket structure 10 is removed from the first installation platform S1, which is a yard installation platform, and the offshore wind turbine jacket structure 10 is transported onto ship B using a crane, transport trolley, skid beam, etc. Then, the legs 11 of the offshore wind turbine jacket structure 10 are installed on each of the second installation platforms, which are shipboard installation platforms that were previously installed on ship B in the deployment step, using a crane, etc. Alternatively, for example, the offshore wind turbine jacket structure 10 together with the first installation platform S1, which is a yard installation platform, is moved onto ship B using a crane, transport trolley, skid beam, etc. On ship B, the offshore wind turbine jacket structure 10 is removed from the first installation platform S1, which is a yard installation platform, and the offshore wind turbine jacket structure 10 is moved using a crane, etc., and the legs 11 are installed on each of the second installation platforms, which are shipboard installation platforms that were previously installed on ship B in the deployment step. Furthermore, the framework F of the first mounting platform S1, which is a yard-mounted mounting platform, and the framework F of the second mounting platform, which is a shipboard mounting platform, do not need to be the same.

[0065] <Variation 1-5> In the installation platform system and movement method according to Modification 1-4, the first installation platform S1, which is a yard installation platform, and the second installation platform, which is a shipboard installation platform, are described as having different configurations but sharing the same frame F. In contrast, in the installation platform system and movement method according to Modification 1-5, the first installation platform S1, which is a yard installation platform, and the second installation platform, which is a shipboard installation platform, have different configurations, including their frame structures.

[0066] For example, the first mounting platform S1, which is a yard mounting platform, only needs to be able to distribute the load of the offshore wind turbine jacket structure 10, which is an offshore structure, to the strong yard Y, so it is desirable that it be made small. In contrast, the second mounting platform, which is a shipboard mounting platform, needs to be large enough to span multiple deck support members of ship B, since the strength of the deck B1 of ship B varies depending on the location. If the first mounting platform S1, which is a yard mounting platform, is smaller than this size, the framework of the second mounting platform, which is a shipboard mounting platform, is made larger than the framework F of the first mounting platform S1, which is a yard mounting platform. In this way, by making the configuration of the first mounting platform S1, which is a yard mounting platform, and the second mounting platform, which is a shipboard mounting platform, different from the framework, it is possible to prepare appropriate ones for each. In this case, it is preferable that the second mounting platform, which is a shipboard mounting platform, is also made of steel. Moreover, it is preferable that structural steel is also used for the second mounting platform, which is a shipboard mounting platform. The use of structural steel makes it easier to manufacture the first mounting platform S1, which is a mounting platform for the yard, and the second mounting platform, which is a mounting platform for the ship.

[0067] The method of movement in this case is the same as the method of movement in Modification 1-4. In this case as well, it is preferable that the second mounting platform, which is a mounting platform for use on a ship, is placed on the ship B so as to straddle at least two of the deck support members that support the deck B1 from below, namely the beams and walls. In other words, it is preferable that the second mounting platform is placed on the ship B so as to straddle at least two beams, or at least two walls, or at least one beam and at least one wall. The first mounting platform S1, which is for yard use, and the second mounting platform, which is for shipboard use, do not necessarily have to have different structural frameworks.

[0068] [Second Embodiment] Next, the installation platform system and movement method according to the second embodiment of this disclosure will be described, mainly with reference to Figures 11 and 12, focusing on the differences from the first embodiment. Figure 11 is a front view showing the first mounting base S2 used in the mounting base system 200 according to the second embodiment. Figure 12 is a perspective view showing the first mounting base S2 used in the mounting base system 200 according to the second embodiment.

[0069] The mounting platform system 100 and relocation method according to the first embodiment and variations 1-1 to 1-5 target an offshore wind turbine jacket structure 10 as an offshore structure. In contrast, the mounting platform system 200 and relocation method according to the second embodiment (the mounting platform system and relocation method according to variations 2-1 to 2-5 described later are similar) target an offshore wind turbine monopile foundation 210 (offshore structure) that supports an offshore wind turbine as an offshore structure. The offshore wind turbine monopile foundation 210 is also a fixed-bottom foundation.

[0070] The installation platform system 200 according to the second embodiment includes a yard installation platform on which a monopile foundation 210 for an offshore wind turbine is installed and which is placed in yard Y, and a shipboard installation platform on which a monopile foundation 210 for an offshore wind turbine is installed and which is placed on ship B. Both the yard installation platform and the shipboard installation platform are installed with the monopile foundation 210 for the offshore wind turbine lying down. In the installation platform system 200 according to the second embodiment, the yard installation platform and the shipboard installation platform are the same, or in other words, identical, and are the first installation platform S2 as shown in Figures 11 and 12. The first installation platform S2 has a mirror-symmetric shape. The first installation platform S2 does not have to have a mirror-symmetric shape. Note that the first mounting platform S2 for yard use and the first mounting platform S2 for shipboard use do not have to be the same.

[0071] The first mounting base S2 has a lower frame, the leg portion S2a, which is placed on the ground Y1 of yard Y and the deck B1 of ship B, and an upper, roughly U-shaped portion S2b on which the monopile foundation 210 for the offshore wind turbine is installed in a horizontal position.

[0072] The leg portion S2a comprises a leg body S2a1 and a plurality of lower reinforcing members S2a2a to S2a2e. The leg body S2a1 includes a lower flange S2a11, an upper flange S2a12, and a web S2a13.

[0073] The lower flange S2a11 of the leg body S2a1 is flat and has a rectangular shape that extends horizontally in one direction and spreads horizontally. The web S2a13 of the leg body S2a1 is flat and extends in the same direction as the lower flange S2a11, rising vertically upward from the center of the shorter side of the lower flange S2a11. The web S2a13 has an isosceles trapezoidal shape, becoming shorter towards the top. The upper flange S2a12 of the leg body S2a1 is flat and rectangular in shape, extending horizontally in the same direction as the lower flange S2a11. The upper edge of the web S2a13 is connected to the center of the shorter side of the upper flange S2a12. The length of the upper flange S2a12 in the longer side direction is equal to the length of the upper edge of the web S2a13. The leg body S2a1 is made of steel, and known structural steel such as H-beams or I-beams is used.

[0074] The multiple lower reinforcing members S2a2a to S2a2e of the leg portion S2a are all flat plates, all made of steel, and all are provided on the surface side of the web S2a13. The multiple lower reinforcing members S2a2a to S2a2e all extend perpendicularly to the lower flange S2a11, the upper flange S2a12, and the web S2a13, and are all joined to the lower flange S2a11, the upper flange S2a12, and the web S2a13, for example by welding. On the surface side of the web S2a13, the lower reinforcing members S2a2a to S2a2e are arranged at predetermined intervals in the direction in which the web S2a13 extends, in the order of lower reinforcing member S2a2a, lower reinforcing member S2a2b, lower reinforcing member S2a2c, lower reinforcing member S2a2d, and lower reinforcing member S2a2e.

[0075] The lower reinforcing member S2a2c is located at the center of the web S2a13 in the direction of extension. The lower reinforcing members S2a2b and S2a2d are located symmetrically at equidistant positions from the lower reinforcing member S2a2c. The lower reinforcing members S2a2a and S2a2e are also located symmetrically at equidistant positions from the lower reinforcing member S2a2c. The distance between the lower reinforcing member S2a2c and either the lower reinforcing member S2a2b or the lower reinforcing member S2a2d is longer than the distance between the lower reinforcing member S2a2b and the lower reinforcing member S2a2a, and the distance between the lower reinforcing member S2a2d and the lower reinforcing member S2a2e.

[0076] Furthermore, on the back surface of web S2a13, multiple lower reinforcing members similar to the lower reinforcing members S2a2a to S2a2e on the front surface of web S2a13 are provided in the same positions and in the same manner as the lower reinforcing members S2a2a to S2a2e.

[0077] The roughly U-shaped portion S2b includes a base member S2b1, a steel prevention member S2b2, a plurality of upper reinforcing members S2b3a to S2b3f, and a plurality of upper end members S2b4a and S2b4b.

[0078] The base member S2b1 is flat, made of steel, and extends in the same direction as the upper flange S2a12 of the leg portion S2a, rising vertically upward from the center of the short side of the upper flange S2a12. The base member S2b1 is joined to the upper flange S2a12, for example, by welding. The base member S2b1 has a semicircular concave portion S2b1a formed in the center in the direction in which the upper flange S2a12 extends, which is recessed from top to bottom.

[0079] The steel protective member S2b2 is made of steel and is in the shape of a curved plate, specifically a semi-cylindrical surface. The steel protective member S2b2 is placed in the concave portion S2b1a of the base member S2b1 and is joined to the entire concave portion S2b1a at the center in the direction in which the central axis of its curvature extends, for example by welding. The central axis of the curve of the steel protective member S2b2 extends perpendicular to the base member S2b1.

[0080] Multiple upper reinforcing members S2b3a to S2b3f are all flat plates, all made of steel, and all are provided on the surface side of the base member S2b1. Multiple upper reinforcing members S2b3a to S2b3f extend perpendicularly to the base member S2b1 and are all joined to both the base member S2b1 and the steel prevention member S2b2, for example by welding. On the surface side of the base member S2b1, the upper reinforcing members S2b3a to S2b3f are arranged in the order of upper reinforcing member S2b3a, upper reinforcing member S2b3b, upper reinforcing member S2b3c, upper reinforcing member S2b3d, upper reinforcing member S2b3e, and upper reinforcing member S2b3f, spaced apart in the circumferential direction of the steel prevention member S2b2.

[0081] The upper reinforcing member S2b3b extends substantially along the normal direction of the steel prevention member S2b2 from the steel prevention member S2b2 and is joined to the joint position of the lower reinforcing member S2a2a on the upper flange S2a12, for example by welding. The upper reinforcing member S2b3a extends above the upper reinforcing member S2b3b from the steel prevention member S2b2 and is joined substantially along the normal direction of the steel prevention member S2b2 from the steel prevention member S2b2. The upper reinforcing member S2b3c extends vertically downward from the steel prevention member S2b2 and is joined to the joint position of the lower reinforcing member S2a2b on the upper flange S2a12, for example by welding. The upper reinforcing member S2b3e extends substantially along the normal direction of the steel prevention member S2b2 from the steel prevention member S2b2 and is joined to the joint position of the lower reinforcing member S2a2e on the upper flange S2a12, for example by welding. The upper reinforcing member S2b3f extends above the upper reinforcing member S2b3e and substantially along the direction normal to the steel protective member S2b2. The upper reinforcing member S2b3d extends vertically downward from the steel protective member S2b2 and is joined to the joint position of the lower reinforcing member S2a2d on the upper flange S2a12, for example by welding.

[0082] Furthermore, on the back surface of the base member S2b1, multiple upper reinforcing members similar to the upper reinforcing members S2b3a to S2b3f on the front surface of the base member S2b1 are provided in the same positions as the upper reinforcing members S2b3a to S2b3f and in the same manner as the upper reinforcing members S2b3a to S2b3f.

[0083] The multiple upper end members S2b4a and S2b4b are all flat plates, all made of steel, and all are provided at the upper end of the base member S2b1. The multiple upper end members S2b4a and S2b4b extend perpendicularly to the base member S2b1 and are joined to both the base member S2b1 and the steel prevention member S2b2, for example, by welding. The multiple upper end members S2b4a and S2b4b extend substantially along the direction normal to the steel prevention member S2b2. The multiple upper end members S2b4a and S2b4b extend in the same horizontal plane. As described above, the roughly U-shaped portion S2b has a roughly U-shape that opens upward. The first mounting base S2, which includes the leg portion S2a and the roughly U-shaped portion S2b, is made of steel, and structural steel is used. Furthermore, the first mounting platform S2, which serves as both a yard mounting platform and a shipboard mounting platform, does not necessarily have to be made of steel. Furthermore, structural steel is not required to be used in the first mounting platform S2, which serves as both a mounting platform for the yard and a mounting platform for the ship.

[0084] On the first mounting base S2, the offshore wind turbine monopile foundation 210 is installed in a horizontal position, with the cylindrical portion 210a positioned within the roughly U-shaped steel prevention member S2b2 of the offshore wind turbine monopile foundation 210. Here, the inner diameter of the steel prevention member S2b2 is slightly larger than the outer diameter of the cylindrical portion 210a of the offshore wind turbine monopile foundation 210. The steel prevention member S2b2 supports the offshore wind turbine monopile foundation 210 by preventing it from rolling.

[0085] The first mounting platform S2, which serves as both a yard mounting platform and a shipboard mounting platform, includes a substantially U-shaped section S2b. Furthermore, the first mounting platform S2, which serves as both a yard mounting platform and a shipboard mounting platform, is provided with a welded steel prevention member S2b2 to prevent the monopile foundation 210 for the offshore wind turbine from rolling. Please note that the shape of the first mounting base S2 is merely an example.

[0086] In the second embodiment, the moving method involves transporting the first mounting platform S2, which constitutes a yard mounting platform placed in yard Y and on which the offshore wind turbine monopile foundation 210 is installed, onto ship B by a transport trolley, with the offshore wind turbine monopile foundation 210 installed, and placing it on a predetermined mounting position on ship B while the offshore wind turbine monopile foundation 210 remains installed. As a result, the first mounting platform S2, which constitutes a yard mounting platform, becomes a shipboard mounting platform on which the offshore wind turbine monopile foundation 210 is installed and placed on ship B. Therefore, the mounting platform system 200 in the second embodiment includes the first mounting platform S2 which serves as both a yard mounting platform and a shipboard mounting platform. Furthermore, the moving method in the second embodiment includes a moving step of moving the offshore wind turbine monopile foundation 210, which is an offshore structure, together with the first mounting platform S2, which is a yard mounting platform, onto ship B. In this case as well, it is preferable that the first mounting base S2, which is a mounting base for use on a ship, is placed on the ship B so as to straddle at least two or more of the deck support members that support the deck B1 from below, namely the beams and walls. In other words, it is preferable that the first mounting base S2 is placed on the ship B so as to straddle at least two beams, at least two walls, or at least one beam and at least one wall.

[0087] The first mounting platform S2, which serves as both a yard mounting platform and a shipboard mounting platform, is the same for both the yard mounting platform S2 and the shipboard mounting platform S2, and naturally, the lower frame, the legs S2a, are common to both.

[0088] The mounting base system 200 and the moving method according to the second embodiment described above each provide the same effects as those of the first embodiment. Furthermore, the first mounting platform S2, which serves as both a yard mounting platform and a shipboard mounting platform, includes a substantially U-shaped section S2b, allowing the monopile foundation 210 for the offshore wind turbine to be placed more securely on the yard Y or ship B when laid on its side. However, the first mounting platform S2, which serves as both a yard mounting platform and a shipboard mounting platform, does not necessarily have to include the substantially U-shaped section S2b. The first mounting platform S2, which is a mounting platform for the yard, is fitted with a steel prevention member S2b2 by welding to prevent the rolling of the monopile foundation 210 for the offshore wind turbine. Since the first mounting platform S2, which is a mounting platform for the yard, is made of steel, the steel prevention member S2b2 for preventing the rolling of the monopile foundation 210 for the offshore wind turbine can be easily fitted to the first mounting platform S2, which is a mounting platform for the yard. However, the first mounting platform S2, which is a mounting platform for the yard, does not necessarily need to have the steel prevention member S2b2 for preventing the rolling of the monopile foundation 210 for the offshore wind turbine fitted with a steel prevention member S2b2 by welding.

[0089] The mounting base system 200 and the movement method according to the second embodiment described above can also be modified as shown in the following variations 2-1 to 2-5. Furthermore, variations 2-1 to 2-5 can be combined as appropriate.

[0090] <Variation 2-1> The installation platform system 200 and moving method according to the second embodiment describe a case in which the monopile foundation 210 for the offshore wind turbine is moved from yard Y to ship B together with the first installation platform S2 using a transport trolley, and the monopile foundation 210 for the offshore wind turbine is then placed and fixed on ship B via the same first installation platform S2. In contrast, the installation platform system and moving method according to Modification 2-1 describes a case in which the monopile foundation 210 for the offshore wind turbine is moved from yard Y to ship B together with the first installation platform S2 using a skid beam (not shown), and the monopile foundation 210 for the offshore wind turbine is then placed and fixed on ship B via the same first installation platform S2.

[0091] In this case, for example, a laying step is performed to lay the skid beam from yard Y to ship B. In the laying step, the skid beam may be laid from yard Y to ship B below the first installation platform S2, which is located in yard Y and on which the offshore wind turbine monopile foundation 210 is placed. After that, a jacking-up step is performed to jack up the offshore wind turbine monopile foundation 210 together with the first installation platform S2. Then, a placement step is performed to jack down the offshore wind turbine monopile foundation 210 together with the first installation platform S2 on the skid beam. As a result, the offshore wind turbine monopile foundation 210 is placed on the skid beam together with the first installation platform S2. In this state, the monopile foundation 210 for the offshore wind turbine, together with the first mounting platform S2 on which it is placed, is slid along the skid beam to move it, thereby performing a transfer step to move the monopile foundation 210 for the offshore wind turbine, together with the first mounting platform S2 on which it is placed, onto the ship B. In this way, the monopile foundation 210 for the offshore wind turbine, together with the first mounting platform S2, is positioned vertically above the predetermined mounting position, similar to that of the second embodiment. Then, the monopile foundation 210 for the offshore wind turbine, together with the first mounting platform S2, is jacked up. After that, the skid beam is removed, and the monopile foundation 210 for the offshore wind turbine, together with the first mounting platform S2, is jacked down to be placed in the predetermined mounting position, similar to that of the second embodiment. Then, the first mounting platforms S2 are fixed to the ship B. In this case, the movement of the skid beam, specifically the monopile foundation 210 for the offshore wind turbine, may be by being pushed from yard Y to ship B, or by being towed from yard Y to ship B. Note that the skid beam may not be removed from ship B.

[0092] The above describes the moving step of moving the offshore wind turbine monopile foundation 210, which is an offshore structure, onto ship B together with the first installation platform S2, which was being used as a yard, using a skid beam. In this case, the moving step includes a jacking-up step in which the offshore wind turbine monopile foundation 210, which is an offshore structure, together with the first installation platform S2, which is a yard installation platform, and an installation step in which the offshore wind turbine monopile foundation 210 and the first installation platform S2, which is a yard installation platform, that have been jacked up in the jacking-up step, are placed on the skid beam.

[0093] In this modified version 2-1, the offshore monopile foundation 210 for the offshore wind turbine, which is an offshore structure, and the first mounting platform S2, which is a mounting platform for the yard, can be moved more reliably from yard Y to ship B using skid beams.

[0094] <Modification 2-2> In addition to moving the monopile foundation 210 for the offshore wind turbine together with the first mounting platform S2 from yard Y to ship B using a transport trolley as in the second embodiment, or moving the monopile foundation 210 for the offshore wind turbine together with the first mounting platform S2 from yard Y to ship B using a skid beam as in modified example 2-1, it is also possible, as described in modified example 2-2, to move the monopile foundation 210 for the offshore wind turbine together with the first mounting platform S2 from yard Y to ship B using a crane, and then place the monopile foundation 210 for the offshore wind turbine on ship B at a predetermined mounting position similar to that in the second embodiment via the same first mounting platform S2.

[0095] <Modified example 2-3> The installation platform system and moving method according to the second embodiment, modified example 2-1, and modified example 2-2 describe a case in which the monopile foundation 210 for offshore wind turbines is moved from yard Y to ship B together with the first installation platform S2, and the monopile foundation 210 for offshore wind turbines is then placed and fixed on ship B via the same first installation platform S2. In contrast, the installation platform system and moving method according to modified example 2-3 has a common configuration with the first installation platform S2 which is a yard installation platform, but uses a different first installation platform S2 as an on-ship installation platform.

[0096] In this case, the method of movement includes a placement step and an installation step. The placement step is to place the first installation platform S2, which is an onboard installation platform, on the ship B. The installation step is to transfer the monopile foundation 210 for the offshore wind turbine from the first installation platform S2, which is an onboard installation platform for the yard, onto the first installation platform S2 that was placed on the ship B in the placement step.

[0097] In the placement step, for example, it is preferable that the first mounting platform S2, which is a mounting platform for use on a ship, is placed on the ship B so as to straddle at least two or more of the beams and walls, which are deck support members that support the deck B1 from below. That is, it is preferable that the first mounting platform S2 is placed on the ship B so as to straddle at least two beams, at least two walls, or at least one beam and at least one wall.

[0098] In the installation step, for example, at yard Y, the monopile foundation 210 for the offshore wind turbine is removed from the first installation platform S2, which is a yard installation platform, and the monopile foundation 210 for the offshore wind turbine is transported onto ship B using a crane, transport trolley, skid beam, etc. Then, using a crane, etc., the monopile foundation 210 for the offshore wind turbine is installed on the first installation platform S2, which is a shipboard installation platform that was previously installed on ship B in the deployment step. Alternatively, for example, the monopile foundation 210 for the offshore wind turbine is moved from yard Y together with the first installation platform S2, which is a yard installation platform, onto ship B using a crane, transport trolley, skid beam, etc. On ship B, the monopile foundation 210 for the offshore wind turbine is removed from the first installation platform S2, which is a yard installation platform, and the monopile foundation 210 for the offshore wind turbine is installed on the first installation platform S2, which is a shipboard installation platform that was previously installed on ship B in the deployment step, using a crane, etc. Even with this configuration, it is possible to use a common first mounting platform S2 on both yard Y and ship B, thus reducing costs compared to using mounting platforms with different configurations on yard Y and ship B. Furthermore, it is not necessary to use a separate first mounting platform S2, which has the same configuration as the first mounting platform S2 for the yard, as the mounting platform for the ship.

[0099] <Modification 2-4> The installation platform system and movement method according to Modification 2-3 were explained using the example of a case where the first installation platform S2, which is a yard installation platform, and the second installation platform S2, which is a shipboard installation platform, are provided separately with a common configuration. In contrast, in the installation platform system and movement method according to Modification 2-4, the first installation platform S2, which is a yard installation platform, and the second installation platform, which is a shipboard installation platform, have different configurations. It is preferable that the second installation platform, which is a shipboard installation platform, is also made of steel.

[0100] For example, if the first mounting platform S2, which is a yard mounting platform, is unsuitable for use as a shipboard mounting platform, a second mounting platform different from the first mounting platform S2 can be used as the shipboard mounting platform. In this case, it is preferable to use the same frame, legs S2a, for both the first and second mounting platforms. By using the same frame, legs S2a, for the first mounting platform S2 (yard mounting platform) and the same frame, legs, for the second mounting platform (shipboard mounting platform), it becomes possible to simplify the manufacturing and handling of each. Furthermore, by using the same frame, legs S2a, for both the first and second mounting platforms, structural steel will also be used for the second mounting platform (shipboard mounting platform), making the manufacturing of both the first mounting platform S2 (yard mounting platform) and the second mounting platform (shipboard mounting platform) easier.

[0101] In this case, the method of movement includes a placement step of placing the second mounting platform, which is a mounting platform for the ship, on ship B, and an installation step of installing the monopile foundation 210 for the offshore wind turbine, which is an offshore structure and is installed on the first mounting platform S2, which is a mounting platform for the yard, onto the second mounting platform, which is a mounting platform for the ship, that was placed in the placement step.

[0102] In the placement step, it is preferable that the second mounting platform, which is a mounting platform for use on the ship, is placed on the ship B so as to straddle at least two or more of the deck support members that support the deck B1 from below, namely the beams and walls. In other words, it is preferable that the second mounting platform is placed on the ship B so as to straddle at least two beams, or at least two walls, or at least one beam and at least one wall.

[0103] In the installation step, for example, at yard Y, the monopile foundation 210 for the offshore wind turbine is removed from the first installation platform S2, which is a yard installation platform, and transported onto ship B using a crane, transport trolley, skid beam, etc. Then, using a crane, etc., the monopile foundation 210 for the offshore wind turbine is installed on the second installation platform, which is a shipboard installation platform that was previously installed on ship B in the deployment step. Alternatively, for example, the monopile foundation 210 for the offshore wind turbine is moved from yard Y together with the first installation platform S2, which is a yard installation platform, onto ship B using a crane, transport trolley, skid beam, etc. On ship B, the monopile foundation 210 for the offshore wind turbine is removed from the first installation platform S2, which is a yard installation platform, and installed on the second installation platform, which is a shipboard installation platform that was previously installed on ship B in the deployment step, using a crane, etc. Furthermore, the leg portion S2a of the first mounting platform S2, which is a yard-type mounting platform, and the leg portion S2a of the second mounting platform, which is a shipboard mounting platform, do not necessarily have to be the same.

[0104] <Modification 2-5> In the installation platform system and movement method according to Modification 2-4, the first installation platform S2, which is a yard installation platform, and the second installation platform, which is a shipboard installation platform, have different configurations, but the framework, such as the legs S2a, is common to both. In contrast, in the installation platform system and movement method according to Modification 2-5, the first installation platform S2, which is a yard installation platform, and the second installation platform, which is a shipboard installation platform, have different configurations, starting with the framework.

[0105] For example, the first mounting platform S2, which is a yard mounting platform, only needs to be able to distribute the load of the offshore wind turbine monopile foundation 210, which is an offshore structure, to the strong yard Y, so it is desirable that it be made small. In contrast, the second mounting platform, which is a shipboard mounting platform, needs to be large enough to straddle multiple deck support members of ship B, since the strength of the ship's deck B1 varies depending on the location. If the first mounting platform S2, which is a yard mounting platform, is smaller than this size, the framework of the second mounting platform, which is a shipboard mounting platform, will be larger than the leg portion S2a, which is the framework of the first mounting platform S2, which is a yard mounting platform. In this way, by making the configuration of the first mounting platform S2, which is a yard mounting platform, and the second mounting platform, which is a shipboard mounting platform, different from the framework, it is possible to prepare appropriate ones for each. In this case as well, it is preferable that the second mounting platform, which is a shipboard mounting platform, is also made of steel. Moreover, it is preferable that structural steel is also used for the second mounting platform, which is a shipboard mounting platform. The use of structural steel makes it easier to manufacture the first mounting platform S2, which is a mounting platform for yards, and the second mounting platform, which is a mounting platform for ships.

[0106] The method of movement in this case is the same as the method of movement in Modification 2-4. In this case as well, it is preferable that the second mounting platform, which is a mounting platform for use on a ship, is placed on the ship B so as to straddle at least two of the deck support members that support the deck B1 from below, namely the beams and walls. That is, it is preferable that the second mounting platform is placed on the ship B so as to straddle at least two beams, or at least two walls, or at least one beam and at least one wall. Furthermore, the first mounting platform S2, which is for yard use, and the second mounting platform, which is for shipboard use, do not necessarily have to have different structural frameworks.

[0107] [Third Embodiment] Next, the installation stand system and movement method according to the third embodiment of this disclosure will be described, mainly with reference to Figure 13, focusing on the differences from the second embodiment. Figure 13 is a schematic plan view showing the first mounting base S3 used in the mounting base system 300 according to the third embodiment.

[0108] The installation platform system and relocation method according to the third embodiment (the installation platform system and relocation method related to the modified examples 3-1 to 3-5 described later are also applicable) to an offshore wind turbine monopile foundation 210 that supports an offshore wind turbine as an offshore structure.

[0109] The installation platform system 300 according to the third embodiment includes a yard-type installation platform on which the base of the offshore wind turbine monopile foundation 210 is installed and which is placed in a yard, and a shipboard-type installation platform on which the base of the offshore wind turbine monopile foundation 210 is installed and which is placed on a ship. Both the yard-type installation platform and the shipboard-type installation platform are installed with the offshore wind turbine monopile foundation 210 erected. In the installation platform system 300 according to the third embodiment, the yard-type installation platform and the shipboard-type installation platform are the same, in other words, identical, and are the first installation platform S3 as shown in Figure 13. However, the first installation platform S3 which is the yard-type installation platform and the first installation platform S3 which is the shipboard-type installation platform do not have to be the same.

[0110] The first mounting platform S3 has a lower frame S3a that is placed on the ground Y1 of yard Y and the deck B1 of ship B, and an upper mounting section (not shown) on which the offshore wind turbine monopile foundation 210 is installed when it is erected.

[0111] The frame S3a includes beams S3a1. The frame S3a includes multiple beams S3a1. The frame S3a is arranged such that the multiple beams S3a1 form a cross shape overall in plan view. The multiple beams S3a1 are made of steel and can be known structural steel such as H-beams or I-beams, which include a lower flange, an upper flange, and a web. In this case, the lower flange is flat and extends horizontally in one direction. The web is flat and extends in the same direction as the lower flange and rises vertically upward from the center of the short side of the lower flange. The upper flange is flat and extends horizontally in the same direction as the lower flange, and the upper edge of the web is connected to the center of its short side. When known structural steel such as H-beams or I-beams is used, multiple beams S3a1 are joined by welding so that their upper flanges are on the same plane, their webs are joined by welding, and their lower flanges are joined by welding so that they are on the same plane, forming a cross shape in plan view. The first mounting base S3 is made of steel, and structural steel is used. Furthermore, the first mounting platform S3, which serves as both a yard mounting platform and a shipboard mounting platform, does not necessarily have to be made of steel. Furthermore, structural steel is not required to be used in the first mounting platform S3, which serves as both a mounting platform for the yard and a mounting platform for the ship.

[0112] On the first mounting platform S3, the monopile foundation 210 for the offshore wind turbine is installed in an upright position, with the base at its lower end being the mounting section not shown. At this time, the base at the lower end of the monopile foundation 210 for the offshore wind turbine is positioned so as to straddle all the beams S3a1 of the framework S3a in a plan view, as shown in Figure 13. Furthermore, the base at the lower end of the monopile foundation 210 for the offshore wind turbine is positioned so as to be located radially inward in a plan view, where the intersections of all the beams S3a1 are located. Note that the base at the lower end of the monopile foundation 210 for the offshore wind turbine does not necessarily have to straddle all the beams S3a1 of the framework S3a in a plan view. Also, the beams S3a1 may be arranged in a cross shape or a grid shape, as long as they can support the monopile foundation 210 for the offshore wind turbine, and the arrangement is not limited.

[0113] In the third embodiment, the moving method involves transporting the first mounting platform S3, which constitutes a yard mounting platform placed in yard Y and on which the offshore wind turbine monopile foundation 210 is installed, onto ship B by a transport trolley, with the offshore wind turbine monopile foundation 210 installed, and placing it on a predetermined mounting position on ship B while the offshore wind turbine monopile foundation 210 remains installed. As a result, the first mounting platform S3, which constitutes a yard mounting platform, becomes a shipboard mounting platform on which the offshore wind turbine monopile foundation 210 is installed and placed on ship B. Therefore, the mounting platform system 300 in the third embodiment includes the first mounting platform S3 which serves as both a yard mounting platform and a shipboard mounting platform. Furthermore, the moving method in the third embodiment includes a moving step of moving the offshore wind turbine monopile foundation 210, which is an offshore structure, together with the first mounting platform S3, which is a yard mounting platform, onto ship B. In this case as well, it is preferable that the first mounting base S3, which is a mounting base for use on a ship, is placed on the ship B so as to straddle at least two or more of the deck support members that support the deck B1 from below, namely the beams and walls. In other words, it is preferable that the first mounting base S3 is placed on the ship B so as to straddle at least two beams, at least two walls, or at least one beam and at least one wall.

[0114] The first mounting platform S3, which serves as both a yard mounting platform and a shipboard mounting platform, is the same as the first mounting platform S3 used as a yard mounting platform and the first mounting platform S3 used as a shipboard mounting platform, and naturally, the lower frame S3a is common to both.

[0115] The mounting base system 300 and the moving method according to the third embodiment described above each provide the same effects as those of the second embodiment. Furthermore, the first mounting platform S3, which serves as both a yard mounting platform and a shipboard mounting platform, on which the erected monopile foundation 210 for the offshore wind turbine is installed on the base, includes a beam S3a1. This ensures that the erected monopile foundation 210 for the offshore wind turbine can be reliably supported by both the first mounting platform S3, which serves as a yard mounting platform, and the first mounting platform S3, which serves as a shipboard mounting platform. The first mounting platform S3, which serves as both a yard mounting platform and a shipboard mounting platform, does not necessarily need to include a beam S3a1.

[0116] The mounting base system 300 and the movement method according to the third embodiment described above can also be modified as shown in the following modified examples 3-1 to 3-5. Furthermore, modified examples 3-1 to 3-5 can be combined as appropriate.

[0117] <Variation 3-1> The installation platform system 300 and moving method according to the third embodiment describe a case in which the monopile foundation 210 for the offshore wind turbine is moved from yard Y to ship B together with the first installation platform S3 using a transport trolley, and the monopile foundation 210 for the offshore wind turbine is then placed and fixed on ship B via the same first installation platform S3. In contrast, in the installation platform system and moving method according to Modification 3-1, the monopile foundation 210 for the offshore wind turbine is moved from yard Y to ship B together with the first installation platform S3 using a skid beam (not shown), and the monopile foundation 210 for the offshore wind turbine is then placed and fixed on ship B via the same first installation platform S3.

[0118] In this case, for example, a laying step is performed to lay the skid beam from yard Y to ship B. In the laying step, the skid beam may be laid from yard Y to ship B below the first mounting platform S3, which is located in yard Y and on which the offshore wind turbine monopile foundation 210 is placed. After that, a jacking-up step is performed to jack up the offshore wind turbine monopile foundation 210 together with the first mounting platform S3. Then, a placement step is performed to jack down the offshore wind turbine monopile foundation 210 together with the first mounting platform S3 on the skid beam. As a result, the offshore wind turbine monopile foundation 210 is placed on the skid beam together with the first mounting platform S3. In this state, the monopile foundation 210 for the offshore wind turbine is moved along the skid beam together with the first mounting base S3, thereby performing a transfer step to move the monopile foundation 210 for the offshore wind turbine, together with the first mounting base S3 on which it is placed, onto the ship B. In this way, the monopile foundation 210 for the offshore wind turbine, together with the first mounting base S3, is positioned vertically above the predetermined mounting position, similar to that of the third embodiment. Then, the monopile foundation 210 for the offshore wind turbine, together with the first mounting base S3, is jacked up. After that, the skid beam is removed, and the monopile foundation 210 for the offshore wind turbine, together with the first mounting base S3, is jacked down and placed in the predetermined mounting position, similar to that of the third embodiment, performing a mounting step. Then, the first mounting base S3 is fixed to the ship B. In this case, the movement of the skid beam, specifically the monopile foundation 210 for the offshore wind turbine, may be by being pushed from yard Y to ship B, or by being towed from yard Y to ship B. Note that the skid beam may not be removed from ship B.

[0119] The above describes the moving step of moving the offshore wind turbine monopile foundation 210, which is an offshore structure, onto ship B together with the first installation platform S3, which was being used as a yard, using a skid beam. In this case, the moving step includes a jacking-up step in which the offshore wind turbine monopile foundation 210, which is an offshore structure, together with the first installation platform S3, which is a yard installation platform, and an installation step in which the offshore wind turbine monopile foundation 210 and the first installation platform S3, which are being jacked up in the jacking-up step, are being placed on the skid beam.

[0120] In this modified example 3-1, the offshore wind turbine monopile foundation 210 and the first mounting platform S3, which are offshore structures, can be moved more reliably from yard Y to ship B using skid beams.

[0121] <Modified example 3-2> In addition to moving the monopile foundation 210 for the offshore wind turbine together with the first mounting platform S3 from yard Y to ship B using a transport trolley as in the third embodiment, or moving the monopile foundation 210 for the offshore wind turbine together with the first mounting platform S3 from yard Y to ship B using a skid beam as in modified example 3-1, it is also possible, as described in modified example 3-2, to move the monopile foundation 210 for the offshore wind turbine together with the first mounting platform S3 from yard Y to ship B using a crane, and then place the monopile foundation 210 for the offshore wind turbine on ship B at a predetermined mounting position similar to that in the third embodiment via the same first mounting platform S3.

[0122] <Modified example 3-3> The installation platform system and moving method according to the third embodiment, modified example 3-1, and modified example 3-2 describe a case in which the monopile foundation 210 for offshore wind turbines is moved from yard Y to ship B together with the first installation platform S3, and the monopile foundation 210 for offshore wind turbines is then placed and fixed on ship B via the same first installation platform S3. In contrast, the installation platform system and moving method according to modified example 3-3 have a common configuration with the first installation platform S3 which is a yard installation platform, but a different first installation platform S3 is used as an on-ship installation platform.

[0123] In this case, the method of movement includes a placement step of placing the first mounting platform S3, which is a mounting platform for the ship, on the ship B, and an installation step of installing the monopile foundation 210 for the offshore wind turbine, which is a marine structure installed on the first mounting platform S3, which is a mounting platform for the yard, on the first mounting platform S3, which is a mounting platform for the ship, which was placed in the placement step.

[0124] In the placement step, for example, it is preferable that the first mounting platform S3, which is a mounting platform for use on a ship, is placed on the ship B so as to straddle at least two or more of the beams and walls, which are deck support members that support the deck B1 from below. That is, it is preferable that the first mounting platform S3 is placed on the ship B so as to straddle at least two beams, at least two walls, or at least one beam and at least one wall.

[0125] In the installation step, for example, at yard Y, the monopile foundation 210 for the offshore wind turbine is removed from the first installation platform S3, which is a yard installation platform, and the monopile foundation 210 for the offshore wind turbine is transported onto ship B using a crane, transport trolley, skid beam, etc. Then, using a crane, etc., the monopile foundation 210 for the offshore wind turbine is installed on the first installation platform S3, which is a shipboard installation platform that was previously installed on ship B in the deployment step. Alternatively, for example, the monopile foundation 210 for the offshore wind turbine is moved from yard Y together with the first installation platform S3, which is a yard installation platform, onto ship B using a crane, transport trolley, skid beam, etc. On ship B, the monopile foundation 210 for the offshore wind turbine is removed from the first installation platform S3, which is a yard installation platform, and the monopile foundation 210 for the offshore wind turbine is installed on the second installation platform, which is a shipboard installation platform that was previously installed on ship B in the deployment step, using a crane, etc. With this configuration, it is possible to use the first mounting platform S3 with a common configuration on both yard Y and ship B, thus reducing costs compared to using mounting platforms with different configurations on both yard Y and ship B. Furthermore, since it has the same configuration as the first mounting platform S3 which is a yard mounting platform, it is not necessary to use a separate first mounting platform S3 as a shipboard mounting platform, distinct from the first mounting platform S3 which is a yard mounting platform.

[0126] <Modification 3-4> The installation platform system and movement method according to Modification 3-3 were explained using the example of a case where the first installation platform S3, which is a yard installation platform, and the second installation platform S3, which is a shipboard installation platform, are provided separately with a common configuration. In contrast, in the installation platform system and movement method according to Modification 3-4, the first installation platform S3, which is a yard installation platform, and the second installation platform, which is a shipboard installation platform, have different configurations. It is preferable that the second installation platform, which is a shipboard installation platform, is also made of steel.

[0127] For example, if the first mounting platform S3, which is a yard mounting platform, is unsuitable for use as a shipboard mounting platform, a second mounting platform different from the first mounting platform S3 can be used as the shipboard mounting platform. In this case, it is preferable to use the same frame S3a for both the first mounting platform S3 and the second mounting platform. By using the same frame S3a for the first mounting platform S3, which is a yard mounting platform, and the same frame for the second mounting platform, which is a shipboard mounting platform, it becomes possible to simplify the manufacturing and handling of each. Furthermore, if the same frame S3a is used for both the first and second mounting platforms, structural steel will also be used for the third mounting platform, which is a shipboard mounting platform, making it easier to manufacture both the first mounting platform S3, which is a yard mounting platform, and the second mounting platform, which is a shipboard mounting platform.

[0128] In this case, the method of movement includes a placement step of placing the second mounting platform, which is a mounting platform for the ship, on ship B, and an installation step of installing the monopile foundation 210 for the offshore wind turbine, which is an offshore structure and is installed on the first mounting platform S3, which is a mounting platform for the yard, onto the second mounting platform, which is a mounting platform for the ship, that was placed in the placement step.

[0129] In the placement step, it is preferable that the second mounting platform, which is a mounting platform for use on the ship, is placed on the ship B so as to straddle at least two or more of the deck support members that support the deck B1 from below, namely the beams and walls. In other words, it is preferable that the second mounting platform is placed on the ship B so as to straddle at least two beams, or at least two walls, or at least one beam and at least one wall.

[0130] In the installation step, for example, at yard Y, the monopile foundation 210 for the offshore wind turbine is removed from the first installation platform S3, which is the yard installation platform, and the monopile foundation 210 for the offshore wind turbine is transported onto ship B using a crane, transport trolley, skid beam, etc. Then, using a crane, etc., the second installation platform, which is the shipboard installation platform that was previously installed on ship B in the deployment step, is installed on the monopile foundation 210 for the offshore wind turbine. Alternatively, for example, the monopile foundation 210 for the offshore wind turbine is moved from yard Y together with the first installation platform S3, which is the yard installation platform, onto ship B using a crane, transport trolley, skid beam, etc. On ship B, the monopile foundation 210 for the offshore wind turbine is removed from the first installation platform S3, which is the yard installation platform, and the monopile foundation 210 for the offshore wind turbine is installed using a crane, etc., onto the second installation platform, which is the shipboard installation platform that was previously installed on ship B in the deployment step. Furthermore, the framework S3a of the first mounting platform S3, which is a yard-mounted mounting platform, and the framework of the second mounting platform, which is a shipboard mounting platform, do not need to be the same.

[0131] <Modified example 3-5> In the installation platform system and movement method according to Modification 3-4, the first installation platform S3, which is a yard installation platform, and the second installation platform, which is a shipboard installation platform, have different configurations, but their framework S3a is the same. In contrast, in the installation platform system and movement method according to Modification 3-5, the framework S3a of the first installation platform S3, which is a yard installation platform, and the framework of the second installation platform, which is a shipboard installation platform, are different.

[0132] For example, the first mounting platform S3, which is a yard mounting platform, only needs to be able to distribute the load of the offshore wind turbine monopile foundation 210, which is an offshore structure, to the strong yard Y, so it is desirable that it be made small. In contrast, the second mounting platform, which is a shipboard mounting platform, needs to be large enough to straddle multiple deck support members of ship B, since the strength of the deck B1 of ship B varies depending on the location. If the first mounting platform S3, which is a yard mounting platform, is smaller than this size, the framework of the second mounting platform, which is a shipboard mounting platform, will be larger than the framework S3a of the first mounting platform S3, which is a yard mounting platform. In this way, by making the configuration of the first mounting platform S3, which is a yard mounting platform, and the second mounting platform, which is a shipboard mounting platform, different from the framework, it is possible to prepare appropriate ones for each. In this case, it is preferable that the second mounting platform, which is a shipboard mounting platform, is also made of steel. Moreover, it is preferable that structural steel is also used for the second mounting platform, which is a shipboard mounting platform. The use of structural steel makes it easier to manufacture the first mounting platform S3, which is a mounting platform for yards, and the second mounting platform, which is a mounting platform for ships.

[0133] The method of movement in this case is the same as the method of movement in Modification 3-4. In this case as well, it is preferable that the second mounting platform, which is a mounting platform for use on a ship, is placed on the ship B so as to straddle at least two of the deck support members that support the deck B1 from below, namely the beams and walls. In other words, it is preferable that the second mounting platform is placed on the ship B so as to straddle at least two beams, or at least two walls, or at least one beam and at least one wall. Furthermore, the first mounting platform S3, which is for yard use, and the second mounting platform, which is for shipboard use, do not necessarily have to have different structural frameworks.

[0134] [Fourth Embodiment] Next, the installation platform system and movement method according to the first embodiment of this disclosure will be described, mainly with reference to Figure 14, focusing on the differences from the first embodiment. Figure 14 is a schematic side view showing the mounting base system 400 according to the fourth embodiment.

[0135] The installation platform system 400 and movement method according to the fourth embodiment (the installation platform system and movement method related to the modified examples 4-1 to 4-6 described later are also applicable) target a jacket-type structure 410 as an offshore structure. Examples of jacket-type structures 410 include jacket-type structures used as piers, jacket-type structures for petroleum-related facilities, and jacket-type structures for gas-related facilities. The jacket-type structure 410 includes a plurality of legs 41 (bases) that extend vertically and are positioned at the intersections of a grid in a plan view, and an upper girder 42 that connects and integrates the upper parts of these legs 41. The plurality of legs 41 and the upper girder 42 are made of steel. Each of the plurality of legs 41 of the jacket-type structure 410 is externally or internally fitted to a steel pipe pile (not shown) driven into the seabed and supported by the steel pipe pile. The jacket-type structure 410 is installed, for example, on the seaward side of a quay so as to extend perpendicular to the quay wall of a port. Here, the seabed ground where the jacket-type structure 410 is installed is such that, for example, the seabed near the quay becomes shallower the closer it is to the quay. Accordingly, the length of the legs 41 of the jacket-type structure 410 is shorter the closer it is to the quay.

[0136] To improve efficiency in manufacturing and transportation, the jacket-type structure 410 has temporary legs 43 attached to or connected to the underside of the legs 41 as needed, so that the combined length of the legs 41 and temporary legs 43 is the same for all legs 41. These temporary legs 43 are removed before the legs 41 are externally or internally inserted into the steel pipe piles. The temporary legs 43 are made of steel.

[0137] The installation platform system 400 according to the fourth embodiment includes a yard installation platform placed in yard Y, on which multiple legs 41 of the jacket-type structure 410 are each installed either directly or via temporary legs 43, and a shipboard installation platform placed on a ship, on which multiple legs 41 of the jacket-type structure 410 are each installed either directly or via temporary legs 43. In the installation platform system 400 according to the fourth embodiment, the yard installation platform and the shipboard installation platform are the same, in other words identical, and constitute the first installation platform S4. The legs 41 of the first installation platform S4 are installed either directly or via temporary legs 43.

[0138] The first mounting base S4 is preferably made of a known structural steel such as an H-beam or I-beam. The first mounting base S4 is made of steel.

[0139] When moving the jacket-type structure 410 assembled in yard Y to the transport ship B, each of the multiple legs 41, along with the first mounting base S4, is jacked up on the ground Y1 of yard Y using a transport trolley, and the entire jacket-type structure 410 is moved onto the deck B1 of ship B by moving the transport trolley. At this time, transfer plates (not shown) that each transport trolley can travel on are appropriately installed between the ground Y1 of yard Y and the deck B1 of ship B.

[0140] Then, the jacket-type structure 410, which has been moved onto the deck B1 of ship B, is positioned at a predetermined mounting location. That is, each of the multiple legs 41 is transported on the deck B1 of ship B, together with the first mounting base S4, using a transport trolley, and each is positioned vertically above its predetermined mounting location. Then, each of the multiple legs 41 is simultaneously jacked down using the transport trolley. As a result, each of the multiple legs 41, either directly or via the temporary legs 43, is placed on the first mounting base S4 at its predetermined mounting location on the deck B1. At this time, each of the first mounting bases S4 is placed on ship B such that it straddles at least two or more of the deck support members that support the deck B1 from below, namely the beams and walls. That is, the first mounting platform S4 is placed on the ship B such that it straddles at least two beams, at least two walls, or at least one beam and at least one wall. Then, the multiple first mounting platforms S4 placed in predetermined mounting positions on the deck B1 are each appropriately fixed to the deck B1.

[0141] The above describes the movement steps for moving the jacket-type structure 410, which is an offshore structure, onto ship B, along with the first mounting platform S4 which was used for yard Y. When the jacket-type structure 410 is jacked down on ship B, the transport trolley will move, for example, from ship B towards yard Y.

[0142] Then, with the jacket-type structure 410 installed on the ship B via the first mounting base S4, each of the first mounting bases S4 is appropriately fixed to the deck B1 of the ship B. The ship B, with the jacket-type structure 410 loaded via the first mounting bases S4 in this state, is transported, for example, to the installation site. At the installation site, the jacket-type structure 410 is removed from the first mounting base S4 or removed from the temporary legs 43, and then installed at the installation site, for example, by a crane or the like.

[0143] Accordingly, the installation platform system 400 of the fourth embodiment on which the jacket-type structure 410 is installed includes a first installation platform S4 on which the legs 41, which are the base of the jacket-type structure 410, are installed either directly or via temporary legs 43.

[0144] Furthermore, in this mounting platform system 400, the first mounting platform S4 serves as both a yard mounting platform placed in yard Y and a shipboard mounting platform placed on ship B. In other words, this mounting platform system 400 includes the first mounting platform S4, which is a yard mounting platform placed in yard Y, on which the legs 41, which are the base of the jacket-type structure 410, are installed either directly or via temporary legs 43. In addition, this mounting platform system 400 includes the first mounting platform S4, on which the legs 41, which are the base of the jacket-type structure 410, are installed, and which is a shipboard mounting platform placed on ship B.

[0145] Furthermore, the mounting platform system 400 is the same for both the first mounting platform S4, which is for yard use, and the first mounting platform S4, which is for shipboard use. Therefore, the framework of the first mounting platform S4, which is for yard use, and the framework of the first mounting platform S4, which is for shipboard use, are common to the mounting platform system 400.

[0146] Furthermore, the first mounting platform S4 of this mounting platform system 400, which serves as both a yard mounting platform and a shipboard mounting platform, is made of steel. Furthermore, in this mounting platform system 400, the first mounting platform S4, which serves as both a yard mounting platform and a shipboard mounting platform, is made of structural steel such as H-beams or I-beams.

[0147] Furthermore, in this mounting platform system 400, the first mounting platform S4, which serves as the mounting platform for the ship, is placed on the ship B such that it straddles at least two of the deck support members that support the deck B1 from below, namely, the beams and walls. In other words, the first mounting platform S4 is placed on the ship B such that it straddles at least two beams, at least two walls, or at least one beam and at least one wall.

[0148] As described above, the installation platform system 400 according to the fourth embodiment includes a first installation platform S4, which is a yard-use installation platform placed on yard Y, on which the legs 41, which are the base of the jacket-type structure 410, are installed either directly or via temporary legs 43. Furthermore, this installation platform system 400 also includes a first installation platform S4, which is a shipboard-use installation platform placed on ship B, on which the legs 41, which are the base of the jacket-type structure 410, are installed either directly or via temporary legs 43. Therefore, this installation platform system 400 makes it possible to install the legs 41, which are the base of the jacket-type structure 410, which is an offshore structure, on both yard Y and ship B. Furthermore, in this mounting base system 400, the legs 41, which are the base of the jacket-type structure 410, are installed, and the first mounting base S4, which is a yard mounting base placed in yard Y, is made of steel. As a result, the weight of the first mounting base S4, which is a yard mounting base, is lighter in this mounting base system 400 compared to when the first mounting base S4 is made of concrete, because the first mounting base S4, which is a yard mounting base, is made of steel.

[0149] Furthermore, in this mounting platform system 400, the first mounting platform S4 for yard use and the first mounting platform S4 for ship use are the same, i.e., identical. Therefore, this mounting platform system 400 allows the same first mounting platform S4 to be used on both yard Y and ship B. As a result, the number of first mounting platforms S4 used can be reduced, and the transfer of the jacket-type structure 410 from the yard mounting platform to the ship use platform becomes unnecessary, thus achieving significant cost reductions. Note that the first mounting platform S4 for yard use and the first mounting platform S4 for ship use do not necessarily have to be the same.

[0150] Furthermore, in this mounting platform system 400, the first mounting platform S4, which serves as both a yard mounting platform and a shipboard mounting platform, is made of steel. Therefore, this mounting platform system 400 makes it easier to manufacture the first mounting platform S4, which serves as both a yard mounting platform and a shipboard mounting platform, and thus reduces costs. Note that the first mounting platform S4, which serves as both a yard mounting platform and a shipboard mounting platform, does not necessarily have to be made of steel.

[0151] Furthermore, in this mounting platform system 400, structural steel is used for the first mounting platform S4, which serves as both a yard mounting platform and a shipboard mounting platform. Therefore, this mounting platform system 400 makes it easier to manufacture the first mounting platform S4, which is both a yard mounting platform and a shipboard mounting platform, and thus reduces costs. Here, since the jacket-type structure 410 has a large number of legs 41, the load borne by each leg 41 is small. Therefore, structural steel can be used effectively for the first mounting platform S4. However, it is not necessary to use structural steel for the first mounting platform S4, which serves as both a yard mounting platform and a shipboard mounting platform.

[0152] Furthermore, in this mounting platform system 400, the first mounting platform S4, which serves as the onboard mounting platform, is placed on the ship B such that it spans at least two of the deck support members that support the deck B1 from below, namely the beams and walls. In other words, the first mounting platform S4 is placed on the ship B such that it spans at least two beams, at least two walls, or at least one beam and at least one wall. For this reason, even if the structure installed on the first mounting platform S4, which serves as the onboard mounting platform, is a jacket-type structure 410, this mounting platform system 400 can be reliably placed on the ship B.

[0153] Furthermore, the moving method according to the fourth embodiment includes a moving step of moving the jacket-type structure 410, which is an offshore structure, onto the ship B together with the first mounting base S4 that was used for yard Y. In this moving method, since the yard mounting base and the shipboard mounting base are the same first mounting base S4, it is not necessary to transfer the jacket-type structure 410 from the yard mounting base to the shipboard mounting base when moving the jacket-type structure 410 from yard Y to ship B. Moreover, since the first mounting base S4, which is the yard mounting base, is made of steel, the first mounting base S4, which is the yard mounting base, is relatively light, making it possible to easily move the jacket-type structure 410 together with the first mounting base S4, which is the yard mounting base.

[0154] The mounting base system 400 and the method of movement according to the fourth embodiment described above can also be modified as shown in the following modified examples 4-1 to 4-6. Furthermore, modified examples 4-1 to 4-6 can be combined as appropriate.

[0155] <Variation 4-1> The installation platform system 400 and moving method according to the fourth embodiment describe a case in which the jacket-type structure 410 is moved from yard Y to ship B together with the first installation platform S4 using a transport trolley, and the jacket-type structure 410 is then placed and fixed on ship B via the same first installation platform S4. In contrast, in the installation platform system and moving method according to Modification 4-1, the jacket-type structure 410 is moved from yard Y to ship B together with the first installation platform S4 using a skid beam (not shown), and the jacket-type structure 410 is then placed and fixed on ship B via the same first installation platform S1.

[0156] In this case, for example, a laying step is performed to lay the skid beam from yard Y to ship B. In the laying step, the beams of the skid beam may be laid from yard Y to ship B below the first mounting base S4, which is provided in yard Y and on which each of the multiple legs 41 of the jacketed structure 410 is placed either directly or via temporary legs 43. After that, a jacking-up step is performed to jack up the entire jacketed structure 410 by jacking up each of the multiple legs 41 of the jacketed structure 410 together with the first mounting base S4 on which they are placed. After that, a mounting step is performed on the skid beam to jack up each of the multiple legs 41 of the jacketed structure 410 together with the first mounting base S4 on which they are placed. As a result, the multiple legs 41 of the jacketed structure 410 are placed on the skid beam together with the first mounting base S4 on which they are placed. In this state, a transfer step is performed in which the jacket-type structure 410 is moved onto the ship B together with the first mounting base S4 by sliding each of the legs 41 of the jacket-type structure 410 along with the first mounting base S4 on which it is mounted, along with the first mounting base S4 on which it is mounted. In this way, the jacket-type structure 410 is positioned vertically above a predetermined mounting position similar to that of the fourth embodiment, together with the first mounting base S4. Then, the jacket-type structure 410 is jacked up together with the first mounting base S4. After that, the skid beam is removed, and the multiple legs 41 of the jacket-type structure 410 are jacked down together with the first mounting base S4 on which they are mounted, in a mounting step that places them in a predetermined mounting position similar to that of the fourth embodiment. Then, each of the first mounting bases S4 is fixed to the ship B. In this case, the movement of the skid beam may be by being pushed from yard Y to ship B, or by being towed from yard Y to ship B. Note that the skid beam may not be removed from ship B.

[0157] The above describes the moving step of moving the jacket-type structure 410, which is an offshore structure, onto ship B together with the first mounting platform S4, which was used for yard Y, using a skid beam. In this case, the moving step includes a jacking-up step in which the jacket-type structure 410, which is an offshore structure, is jacked up together with the first mounting platform S4, which is a yard mounting platform, and a mounting step in which the jacket-type structure 410 and the first mounting platform S4, which is a yard mounting platform, that have been jacked up in the jacking-up step are placed on the skid beam.

[0158] In this modified example 4-1, the jacket-type structure 410, which is an offshore structure, and the first mounting platform S4, which is a mounting platform for the yard, can be moved more reliably from yard Y to ship B using skid beams.

[0159] <Modification 4-2> In addition to moving the jacket-type structure 410 together with the first mounting base S4 from yard Y to ship B using a transport trolley as in the fourth embodiment, or moving the jacket-type structure 410 together with the first mounting base S4 from yard Y to ship B using a skid beam (not shown) as in modified example 4-1, it is also possible, as in modified example 4-2, to move the jacket-type structure 410 together with the first mounting base S4 from yard Y to ship B using a crane (not shown), and then place it on ship B at a predetermined mounting position similar to the fourth embodiment via the same first mounting base S4.

[0160] <Modification 4-3> The installation platform system and moving method according to the fourth embodiment, modification 4-1, and modification 4-2 describe a case in which the jacket-type structure 410 is moved from yard Y to ship B together with the first installation platform S4, and the jacket-type structure 410 is then placed and fixed on ship B via the same first installation platform S4. In contrast, the installation platform system and moving method according to modification 4-3 has a common configuration with the first installation platform S4 which is a yard installation platform, but uses a different first installation platform S4 as an onboard installation platform.

[0161] In this case, the method of movement includes a placement step of placing the first mounting platform S4, which is a mounting platform for the ship, on the ship B, and an installation step of installing the jacket-type structure 410, which is a marine structure to be installed on the first mounting platform S4, which is a mounting platform for the yard, on the first mounting platform S4, which is a mounting platform for the ship, which is placed in the placement step.

[0162] In the placement step, it is preferable that the first mounting base S4, which is a mounting base for use on the ship, is placed on the ship B so as to be the same as in the fourth embodiment, that it straddles at least two of the beams and walls, which are deck support members that support the deck B1 from below. That is, it is preferable that the first mounting base S4 is placed on the ship B so as to straddle at least two beams, or at least two walls, or at least one beam and at least one wall.

[0163] In the installation step, for example, at yard Y, the jacket-type structure 410 is removed from the first installation platform S4, which is a yard installation platform, and the jacket-type structure 410 is transported onto ship B using a crane, transport trolley, skid beam, etc. Then, using a crane, etc., the legs 41 of the jacket-type structure 410 are installed either directly or via temporary legs 43 onto each of the first installation platforms S4, which are shipboard installation platforms that were previously installed on ship B in the placement step. Furthermore, for example, the jacket-type structure 410, along with the first mounting platform S4 which is a yard mounting platform, is moved from yard Y onto ship B using a crane, transport trolley, skid beam, etc. On ship B, the jacket-type structure 410 is removed from the first mounting platform S4 which is a yard mounting platform, and the legs 41 of the jacket-type structure 410 are installed either directly or via temporary legs 43 on each of the first mounting platforms S4 which are shipboard mounting platforms that were previously installed on ship B in the setup step, using a crane, etc.

[0164] With this configuration, it is possible to use the first mounting platform S4 with a common configuration on both yard Y and ship B, thus reducing costs compared to using mounting platforms with different configurations on both yard Y and ship B.

[0165] Furthermore, for example, the first mounting platform S4, which is a yard mounting platform and the first mounting platform S4, which is a shipboard mounting platform, on which one leg 41 of the jacket-type structure 410 is installed, can be made into a simple structure and manufactured at low cost because they bear a small load. For this reason, it is more rational to prepare the first mounting platform S4 for yard use and the first mounting platform S4 for shipboard use separately, and to install the first mounting platform S4 for shipboard use on ship B before moving the jacket-type structure 410. Furthermore, since it has the same configuration as the first mounting platform S4 which is a yard mounting platform, it is not necessary to use a separate first mounting platform S4 as a shipboard mounting platform, distinct from the first mounting platform S4 which is a yard mounting platform.

[0166] <Modification 4-4> The installation platform system and movement method according to Modification 4-3 were explained using the example of a case where the first installation platform S4, which is a yard installation platform, and the first installation platform S4, which is a shipboard installation platform, are provided separately with a common configuration. In contrast, in the installation platform system and movement method according to Modification 4-4, the first installation platform S4, which is a yard installation platform, and the second installation platform (not shown), which is a shipboard installation platform, have different configurations. It is preferable that the second installation platform, which is a shipboard installation platform, is also made of steel.

[0167] For example, if the first mounting platform S4, which is a yard mounting platform, is unsuitable for use as a shipboard mounting platform, a second mounting platform different from the first mounting platform S4 may be used as the shipboard mounting platform. In this case, it is preferable to use the same framework for both the first and second mounting platforms. By using the same framework for the first mounting platform S4 (yard mounting platform) and the second mounting platform (shipboard mounting platform), it becomes possible to simplify the manufacturing and handling of each. Furthermore, if the frameworks of the first and second mounting platforms S4 and S4 are common, structural steel will also be used for the second mounting platform (shipboard mounting platform), making the manufacturing of both the first mounting platform S4 (yard mounting platform) and the second mounting platform (shipboard mounting platform) easier. Here, the framework of the mounting platform refers to the arrangement (positional relationship) of the members included in the mounting platform, and even if the frameworks of the two mounting platforms are the same, the sizes of the two mounting platforms may differ. In this case, the two mounting platforms are similar in shape.

[0168] In this case, the method of movement includes a placement step of placing a second mounting platform, which is a mounting platform for the ship, on ship B, and an installation step of installing a jacket-type structure 410, which is a marine structure and is installed on the first mounting platform S4, which is a mounting platform for the yard, onto the second mounting platform, which is a mounting platform for the ship, that was placed in the placement step.

[0169] In the placement step, it is preferable that the second mounting platform, which is a mounting platform for use on the ship, is placed on the ship B so as to straddle at least two or more of the deck support members that support the deck B1 from below, namely the beams and walls. In other words, it is preferable that the second mounting platform is placed on the ship B so as to straddle at least two beams, or at least two walls, or at least one beam and at least one wall.

[0170] In the installation step, for example, at yard Y, the jacketed structure 410 is removed from the first installation platform S4, which is a yard installation platform, and the jacketed structure 410 is transported onto ship B using a crane, transport trolley, skid beam, etc. Then, using a crane, etc., the legs 41 of the jacketed structure 410 are installed either directly or via temporary legs 43 onto each of the second installation platforms, which are onboard installation platforms that were previously installed on ship B in the deployment step. Alternatively, for example, the jacketed structure 410 together with the first installation platform S4, which is a yard installation platform, is moved from yard Y onto ship B using a crane, transport trolley, skid beam, etc. On ship B, the jacketed structure 410 is removed from the first installation platform S4, which is a yard installation platform, and the jacketed structure 410 is moved using a crane, etc., and the legs 41 are installed either directly or via temporary legs 43 onto each of the second installation platforms, which are onboard installation platforms that were previously installed on ship B in the deployment step. Furthermore, the framework F of the first mounting platform S4, which is a yard-mounted mounting platform, and the framework of the second mounting platform, which is a shipboard mounting platform, do not need to be the same.

[0171] <Modification 4-5> In the installation platform system and movement method according to Modification 4-4, the first installation platform S4, which is a yard installation platform, and the second installation platform, which is a shipboard installation platform, were described as having different configurations but sharing the same framework. In contrast, in the installation platform system and movement method according to Modification 4-5, the first installation platform S4, which is a yard installation platform, and the second installation platform, which is a shipboard installation platform, have different configurations, including their frameworks.

[0172] For example, the first mounting platform S4, which is a yard mounting platform, only needs to be able to distribute the load of the jacket-type structure 410, which is an offshore structure, to the strong yard Y, so it is desirable that it be made small. In contrast, the second mounting platform, which is a shipboard mounting platform, needs to be large enough to span multiple deck support members of ship B, since the strength of the deck B1 of ship B varies depending on the location. If the first mounting platform S4, which is a yard mounting platform, is smaller than this size, the framework of the second mounting platform, which is a shipboard mounting platform, is made larger than the framework of the first mounting platform S4, which is a yard mounting platform. In this way, by making the configuration of the first mounting platform S4, which is a yard mounting platform, and the second mounting platform, which is a shipboard mounting platform, different from the framework, it is possible to prepare appropriate ones for each. In this case, it is preferable that the second mounting platform, which is a shipboard mounting platform, is also made of steel. Moreover, it is preferable that structural steel is also used for the second mounting platform, which is a shipboard mounting platform. The use of structural steel makes it easier to manufacture the first mounting platform S4, which is a mounting platform for yards, and the second mounting platform, which is a mounting platform for ships.

[0173] Furthermore, for example, the first mounting platform S4, which is a yard mounting platform, and the second mounting platform, which is a shipboard mounting platform, both of which are installed on one leg 41 of the jacket-type structure 410, can be made into a simple structure and manufactured at a low cost because they bear a small load. For this reason, even if the first mounting platform S4, which is a yard mounting platform, and the second mounting platform, which is a shipboard mounting platform, are prepared separately, the increase in cost can be suppressed, and the second mounting platform, which is a shipboard mounting platform, can be installed on ship B before the jacket-type structure 410 is moved, which allows for rational work.

[0174] The method of movement in this case is the same as the method of movement in Modification 4-4. In this case as well, it is preferable that the second mounting platform, which is a mounting platform for use on a ship, is placed on the ship B so as to straddle at least two or more of the deck support members that support the deck B1 from below, namely the beams and walls. That is, it is preferable that the second mounting platform S1 is placed on the ship B so as to straddle at least two beams, or at least two walls, or at least one beam and at least one wall. Furthermore, the first mounting platform S4, which is for yard use, and the second mounting platform, which is for shipboard use, do not necessarily have to have different structural frameworks.

[0175] <Modification 4-6> In the fourth embodiment and modifications 4-1 to 4-5, a temporary leg 43 is provided to make the combined length of the leg 41 and the temporary leg 43 the same in the jacket-type structure 410. However, in the fourth embodiment and modifications 4-1 to 4-5, instead of providing a temporary leg 43, a first mounting base S4 of a height corresponding to the length of each leg 41 may be prepared to make the combined length of the leg 41 and the first mounting base S4 the same. In this case, it is preferable to individually manufacture the first mounting base S4 of a height corresponding to the length of each leg 41, and if there are multiple legs 41 of the same length, to manufacture multiple first mounting bases S4 common to them. In modifications 4-4 and 4-5, for the second mounting base as well, a second mounting base of a height corresponding to the length of each leg 41 may be prepared to make the combined length of the leg 41 and the second mounting base the same. In this case as well, it is preferable to individually manufacture a second mounting base of a height corresponding to the length of each leg 41, and if there are multiple legs 41 of the same length, to manufacture multiple second mounting bases common to them.

[0176] It is also possible to have a first system that includes the mounting stand system 100 according to the first embodiment and any one of the modifications 1-1 to 1-5, or the mounting stand system 200 according to the second embodiment and any one of the modifications 2-1 to 2-5, or the mounting stand system 300 according to the third embodiment and any one of the modifications 3-1 to 3-5, and the mounting stand system 400 according to the fourth embodiment and any one of the modifications 4-1 to 4-5.

[0177] This first system includes a first mounting platform system on which a fixed-bottom foundation is installed, which includes an offshore wind turbine jacket structure 10 that supports the offshore wind turbine, or an offshore wind turbine monopile foundation 210 that supports the offshore wind turbine, and a second mounting platform system on which a jacket structure 410 is installed.

[0178] This first system includes a first mounting platform system which comprises a first yard mounting platform on which a jacket structure 10 for an offshore wind turbine, which is a bottom-fixed foundation, is installed and which is located in yard Y, and a first shipboard mounting platform on which a jacket structure 10 for an offshore wind turbine, which is a bottom-fixed foundation, is installed and which is located on ship B. Alternatively, the first system includes a first yard-based installation platform on which a monopile foundation 210 for an offshore wind turbine, which is a bottom-fixed foundation, is installed and which is located in yard Y, and a first ship-based installation platform on which a monopile foundation 210 for an offshore wind turbine, which is a bottom-fixed foundation, is installed and which is located on ship B.

[0179] This first system includes a second mounting platform system which comprises a second yard mounting platform on which the leg 41 of the jacket-type structure 410 is mounted and which is located in yard Y, and a second onboard mounting platform on which the leg 41 of the jacket-type structure 410 is mounted and which is located on ship B.

[0180] In this first system, the mounting platform for the first yard is made of steel. In this first system, the mounting platform for the second yard is also made of steel, and structural steel is used.

[0181] It is also possible to provide a second system which includes one of the following: the mounting stand system 100 according to the first embodiment, modified example 1-1, and modified example 1-2; the mounting stand system 200 according to the second embodiment, modified example 2-1, and modified example 2-2; or the mounting stand system 300 according to the third embodiment, modified example 3-1, and modified example 3-2, and one of the following: modified example 3-4, modified example 3-5, modified example 4-4, and modified example 4-5.

[0182] This second system includes a first mounting platform system on which a fixed-bottom foundation is installed, which includes an offshore wind turbine jacket structure 10 that supports the offshore wind turbine, or an offshore wind turbine monopile foundation 210 that supports the offshore wind turbine, and a second mounting platform system on which a jacket structure 410 is installed. This second system includes a first mounting platform system which comprises a first yard mounting platform on which a jacket structure 10 for an offshore wind turbine, which is a bottom-fixed foundation, is installed and which is located in yard Y, and a first shipboard mounting platform on which a jacket structure 10 for an offshore wind turbine, which is a bottom-fixed foundation, is installed and which is located on ship B. Alternatively, the second system includes a first yard-based mounting platform on which a monopile foundation 210 for an offshore wind turbine, which is a bottom-fixed foundation, is installed and which is located in yard Y, and a first ship-based mounting platform on which a monopile foundation 210 for an offshore wind turbine, which is a bottom-fixed foundation, is installed and which is located on ship B.

[0183] This second system includes a second yard-mounted platform on which the leg 41 of the jacket-type structure 410 is installed and which is located in yard Y, and a second onboard platform on which the leg 41 of the jacket-type structure 410 is installed and which is located on ship B.

[0184] In this second system, the mounting platform for the first yard is made of steel, and the mounting platform for the first yard and the mounting platform for the first shipboard are identical. This second system has different mounting platforms for the second yard and the second onboard vessel.

[0185] A third system is also possible, which includes one of the following: the mounting stand system 100 according to the first embodiment, modified example 1-1, and modified example 1-2; the mounting stand system 200 according to the second embodiment, modified example 2-1, and modified example 2-2; or the mounting stand system 300 according to the third embodiment, modified example 3-1, and modified example 3-2; and one of the following: the mounting stand system 400 according to the fourth embodiment, modified example 4-1, and modified example 4-2.

[0186] This third system includes a first mounting platform system on which a fixed-bottom foundation is installed, which includes an offshore wind turbine jacket structure 10 that supports the offshore wind turbine, or an offshore wind turbine monopile foundation 210 that supports the offshore wind turbine, and a second mounting platform system on which a jacket structure 410 is installed. This third system includes a first mounting platform system which comprises a first yard mounting platform on which a jacket structure 10 for an offshore wind turbine, which is a bottom-fixed foundation, is installed and which is located in yard Y, and a first shipboard mounting platform on which a jacket structure 10 for an offshore wind turbine, which is a bottom-fixed foundation, is installed and which is located on ship B. Alternatively, this third system includes a first mounting platform system which includes a first yard mounting platform on which a monopile foundation 210 for an offshore wind turbine, which is a bottom-fixed foundation, is installed and which is located in yard Y, and a first shipboard mounting platform on which a monopile foundation 210 for an offshore wind turbine, which is a bottom-fixed foundation, is installed and which is located on ship B.

[0187] This third system includes a second mounting platform system which comprises a second yard mounting platform on which the leg 41 of the jacketed structure 410 is mounted and which is located in yard Y, and a second onboard mounting platform on which the leg 41 of the jacketed structure 410 is mounted and which is located on ship B.

[0188] In this third system, the mounting platform for the first yard is made of steel, and the mounting platform for the first yard and the mounting platform for the first shipboard are identical. This third system uses the same mounting platform for the second yard and the same mounting platform for the second shipboard.

[0189] A fourth system is also possible, which includes the mounting stand system 100 according to the first embodiment and any one of the modifications 1-1 to 1-5, or the mounting stand system 200 according to the second embodiment and any one of the modifications 2-1 to 2-5, or the mounting stand system 300 according to the third embodiment and any one of the modifications 3-1 to 3-5, and a modification 4-6 of the mounting stand system according to the fourth embodiment.

[0190] This fourth system includes a first mounting platform system on which a fixed-bottom foundation is installed, which includes an offshore wind turbine jacket structure 10 that supports the offshore wind turbine, or an offshore wind turbine monopile foundation 210 that supports the offshore wind turbine, and a second mounting platform system on which a jacket structure 410 is installed. This third system includes a first mounting platform system which comprises a first yard mounting platform on which a jacket structure 10 for an offshore wind turbine, which is a bottom-fixed foundation, is installed and which is located in yard Y, and a first shipboard mounting platform on which a jacket structure 10 for an offshore wind turbine, which is a bottom-fixed foundation, is installed and which is located on ship B. Alternatively, the fourth system includes a first yard-based mounting platform on which a monopile foundation 210 for an offshore wind turbine, which is a bottom-fixed foundation, is installed and which is located on yard Y, and a first ship-based mounting platform on which a monopile foundation 210 for an offshore wind turbine, which is a bottom-fixed foundation, is installed and which is located on ship B.

[0191] This fourth system includes a second mounting platform system which comprises a second yard mounting platform on which the leg 41 of the jacketed structure 410 is mounted and which is located in yard Y, and a second onboard mounting platform on which the leg 41 of the jacketed structure 410 is mounted and which is located on ship B. This fourth system has a steel mounting base for the first yard. This fourth system includes a second yard mounting platform and a second onboard mounting platform that are common to multiple legs 41, and a second platform that is individual to each leg 41.

[0192] The technical scope of this disclosure is not limited to the embodiments described above, and various modifications can be made without departing from the spirit of this disclosure.

[0193] Furthermore, it is possible to replace the components in the above embodiments with well-known components as appropriate, without departing from the spirit of this disclosure.

[0194] (Note) The mounting base system according to the above embodiment can be understood, for example, as follows.

[0195] (1) An installation stand system relating to one aspect of this disclosure is: An installation platform system on which offshore structures are installed, The aforementioned offshore structure is installed on a yard-type mounting platform that is placed in the yard, The aforementioned offshore structure is installed on a shipboard mounting platform that is placed on the ship, Includes, The aforementioned yard mounting platform is made of steel. The aforementioned offshore structure includes a fixed-bottom foundation or a jacket-type structure that supports an offshore wind turbine. It is characterized by the following:

[0196] This mounting system includes a yard-mounted mounting platform on which the offshore structure is installed and which is located in the yard, and a shipboard-mounted mounting platform on which the offshore structure is installed and which is located on the ship. Therefore, this mounting system makes it possible to install offshore structures in both the yard and on the ship. Furthermore, in this mounting system, the yard mounting platform, which is placed in the yard where the offshore structure is installed, is made of steel. Therefore, the weight of the yard mounting platform in this system is lighter than if it were made of concrete, because the yard mounting platform is made of steel.

[0197] (2) In the installation stand system relating to (1) above, The framework of the yard-mounted platform and the framework of the shipboard-mounted platform may share a common configuration.

[0198] This configuration makes it possible to easily manufacture and handle both the yard-mounted and onboard mounting platforms.

[0199] (3) In the installation stand system relating to (2) above, The yard mounting platform and the shipboard mounting platform may be the same in their configuration.

[0200] With this configuration, the yard mounting platform and the onboard mounting platform can be the same, making it possible to use the same mounting platform in both the yard and onboard the ship.

[0201] (4) In the installation stand system relating to (2) above, The framework of the yard-mounted platform and the framework of the shipboard-mounted platform may have different configurations.

[0202] This configuration allows for the provision of appropriate mounting platforms for both the yard and the ship.

[0203] (5) In the installation stand system relating to any one of (1) to (4) above, The aforementioned yard mounting platform and the aforementioned shipboard mounting platform may be constructed using structural steel.

[0204] This configuration makes it easier to manufacture mounting platforms for yards and on ships.

[0205] (6) In the installation stand system relating to any one of (1) to (5) above, The aforementioned offshore structure is a jacket-type foundation that supports an offshore wind turbine. The aforementioned shipboard mounting platform may be configured to be placed on the ship so as to straddle multiple deck support members of the ship.

[0206] With this configuration, even if the onboard mounting platform is a heavy object such as a jacket-type foundation, it can be securely placed on the ship.

[0207] (7) In the installation stand system relating to any one of (1) to (5) above, The aforementioned offshore structure is a monopile foundation that supports an offshore wind turbine, and is a monopile foundation in a horizontal position. The yard mounting platform and the shipboard mounting platform may each have a configuration that includes a substantially U-shaped portion.

[0208] This configuration allows for a more secure placement of the horizontally positioned monopile foundation on the yard or ship.

[0209] (8) In the installation platform system described in (7) above, the yard installation platform may be configured such that a steel prevention member for preventing the monopile foundation from rolling is welded to it.

[0210] With this configuration, since the yard mounting base is made of steel, a steel anti-rolling member for the monopile foundation can be easily installed on the yard mounting base to prevent it from rolling.

[0211] (9) In the installation stand system relating to any one of the above (1) to (5), The aforementioned offshore structure is a monopile foundation that supports an offshore wind turbine, and is a monopile foundation in an erected state. The yard mounting platform and the shipboard mounting platform may each include a beam in their configuration.

[0212] With this configuration, the monopile foundation, once erected, can be securely supported by both the yard-mounted platform and the shipboard-mounted platform.

[0213] (10) A method of movement relating to one aspect of this disclosure is: A method for moving the offshore structure using the mounting platform system described in any one of (1), (2), and (4) above, The setup step involves placing the aforementioned shipboard mounting platform on the ship, Installation step: Installing the offshore structure, which is to be installed on the yard installation platform, onto the shipboard installation platform that is positioned in the aforementioned arrangement step, It is characterized by being equipped with [the following features].

[0214] This method of relocation makes it possible to move offshore structures, which are installed on yard-mounted platforms located in the yard, onto shipboard-mounted platforms located on the ship.

[0215] (11) A method of movement relating to one aspect of this disclosure is: A method for moving the offshore structure using the mounting platform system described in (3) above, The present invention is characterized by including a moving step for moving the offshore structure, together with the yard mounting platform, onto the ship.

[0216] This method of movement eliminates the need to transfer offshore structures from the yard platform to the ship's platform when moving them from the yard to the ship, as the yard platform and the ship's platform are the same. Furthermore, because the yard platform is made of steel, it is relatively light, making it possible to move the offshore structure together with the yard platform.

[0217] (12) In the method of movement described in (11) above, The aforementioned movement step is, The aforementioned offshore structure, along with the aforementioned yard mounting platform, is jacked up using a jacking step, A mounting step for placing the offshore structure and the yard installation platform, which are jacked up in the jack-up step, onto the skid beam, It would also be acceptable as a composition that includes this.

[0218] With this configuration, offshore structures and yard mounting platforms can be moved more reliably using skid beams.

[0219] (13) A system relating to one aspect of this disclosure is A system comprising a first mounting platform system on which a bottom-fixed foundation supporting an offshore wind turbine is installed, and a second mounting platform system on which a jacket-type structure is installed, The first mounting base system is The aforementioned fixed-bottom foundation is installed, and a first yard installation platform is placed in the yard, The aforementioned fixed-bottom foundation is installed, and the first onboard mounting platform is placed on the ship, Includes, The second mounting base system is The base of the aforementioned jacket-type structure is installed, and a second yard installation platform is placed in the yard, The base of the aforementioned jacket-type structure is installed, and a second onboard mounting platform is placed on the ship, Includes, The aforementioned mounting platform for the first yard is made of steel. The aforementioned second yard mounting platform is made of steel, and structural steel is used. It is characterized by the following:

[0220] In this system, the base of the jacket-type structure is installed, and the second yard installation platform, which is placed in the yard, is made of steel. Therefore, the weight of the yard installation platform is lighter than if it were made of concrete, because the yard installation platform is made of steel. In addition, since structural steel is used for the second yard installation platform, its manufacture is easier.

[0221] (14) A system relating to one aspect of this disclosure is A system comprising a first mounting platform system on which a bottom-fixed foundation supporting an offshore wind turbine is installed, and a second mounting platform system on which a jacket-type structure is installed, The first mounting base system is The aforementioned fixed-bottom foundation is installed, and a first yard installation platform is placed in the yard, The aforementioned fixed-bottom foundation is installed, and the first onboard mounting platform is placed on the ship, Includes, The second mounting base system is The base of the aforementioned jacket-type structure is installed, and a second yard installation platform is placed in the yard, The base of the aforementioned jacket-type structure is installed, and a second onboard mounting platform is placed on the ship, Includes, The aforementioned mounting platform for the first yard is made of steel. The first yard mounting platform and the first shipboard mounting platform are the same, The second yard mounting platform and the second shipboard mounting platform are different. It is characterized by the following:

[0222] This system features a fixed-bottom foundation, and the first yard platform, located in the yard, is made of steel. Therefore, the weight of the first yard platform is lighter than if it were made of concrete. Furthermore, since the first yard platform and the first onboard platform are identical, the same platform can be used in both the yard and on the ship. The second yard platform, on which the jacketed structure base is installed, and the second onboard platform, on which the jacketed structure base is installed, are different. Because the second yard platform and the second onboard platform, on which the jacketed structure base is installed, bear less load, they can be made with a simpler structure and manufactured at a lower cost. Therefore, even if the second yard platform and the second onboard platform are prepared separately, cost increases can be kept to a minimum, and the second onboard platform can be installed on the ship before the jacketed structure is moved, allowing for more efficient work.

[0223] (15) A system relating to one aspect of this disclosure is A system comprising a first mounting platform system on which a bottom-fixed foundation supporting an offshore wind turbine is installed, and a second mounting platform system on which a jacket-type structure is installed, The first mounting base system is The aforementioned fixed-bottom foundation is installed, and a first yard installation platform is placed in the yard, The aforementioned fixed-bottom foundation is installed, and the first onboard mounting platform is placed on the ship, Includes, The second mounting base system is The base of the aforementioned jacket-type structure is installed, and a second yard installation platform is placed in the yard, The base of the aforementioned jacket-type structure is installed, and a second onboard mounting platform is placed on the ship, Includes, The aforementioned mounting platform for the first yard is made of steel. The first yard mounting platform and the first shipboard mounting platform are the same, The second yard mounting platform and the second onboard mounting platform are the same. characterized in that.

[0224] This system has a seating foundation installed, and the installation platform for the first yard placed in the yard is made of steel. Therefore, the weight of the installation platform for the first yard of this installation platform system is lighter than when the installation platform for the first yard is made of concrete by making the installation platform for the first yard of steel. Also, since the installation platform for the first yard where the seating foundation is installed and the installation platform for the first shipboard are the same, it becomes possible to use the same installation platform in each of the yard and the shipboard. Further, since the installation platform for the second yard where the base of the jacket type structure is installed and the installation platform for the second shipboard are the same, it becomes possible to use the same installation platform in each of the yard and the shipboard.

[0225] (16) The system according to one aspect of the present disclosure is a system including a first installation platform system where a seating foundation for supporting an offshore wind turbine is installed, and a second installation platform system where a jacket type structure is installed, wherein the first installation platform system includes a first yard installation platform where the seating foundation is installed and which is placed in the yard, and a first shipboard installation platform where the seating foundation is installed and which is placed on the ship, and the second installation platform system includes a second yard installation platform where the base of the jacket type structure is installed and which is placed in the yard, and a second shipboard installation platform where the base of the jacket type structure is installed and which is placed on the ship, and the first yard installation platform is made of steel, the second yard installation platform and the second shipboard installation platform include those common to the plurality of bases and those individual to the bases, characterized in that.

[0226] This system features a fixed-bottom foundation, and the first yard platform, located in the yard, is made of steel. Therefore, the weight of the first yard platform is lighter than if it were made of concrete, due to its steel construction. The second yard platform and the second onboard platform, on which the jacketed structure base is installed, include both common components for multiple bases and individual components for each base, allowing for efficient installation of the jacketed structure according to the length of the base. [Explanation of Symbols]

[0227] 10. Jacket structure for offshore wind turbines (offshore structure, jacket-type foundation) 100, 200, 300, 400 installation stand system 210 Monopile foundation for offshore wind turbines (offshore structure) 410 Jacket-type structure B ship B2 Transbeam (deck support member) B3 Longi material F Frame S1~S4 1st installation stand S2a Leg section (framework) S2b U-shaped part S2b2 Steel protective member S3a1 Beam Y Yard

Claims

1. An installation platform system on which offshore structures are installed, The aforementioned offshore structure is installed on a yard-type mounting platform that is placed in the yard, The aforementioned offshore structure is installed on a shipboard mounting platform that is placed on the ship, Includes, The aforementioned yard mounting platform is made of steel. The aforementioned offshore structure includes a fixed-bottom foundation or a jacket-type structure that supports an offshore wind turbine. A mounting stand system characterized by the following features.

2. The framework of the yard-mounted platform and the framework of the shipboard-mounted platform are common to each other. The mounting stand system according to feature 1.

3. The aforementioned mounting platform for the yard and the aforementioned mounting platform for the ship are the same. The mounting stand system according to feature 2.

4. The framework of the yard-mounted platform and the framework of the shipboard-mounted platform are different. The mounting stand system according to feature 1.

5. The aforementioned yard mounting platform and the aforementioned shipboard mounting platform are made of structural steel. The mounting stand system according to any one of claims 1 to 4.

6. The aforementioned offshore structure is a jacket-type foundation that supports an offshore wind turbine. The aforementioned shipboard mounting platform is placed on the ship so as to straddle multiple deck support members. The mounting stand system according to any one of claims 1 to 4.

7. The aforementioned offshore structure is a monopile foundation that supports an offshore wind turbine, and is a monopile foundation in a horizontal position. Each of the aforementioned yard mounting platform and shipboard mounting platform includes a substantially U-shaped portion. The mounting stand system according to any one of claims 1 to 4.

8. The aforementioned yard mounting platform is provided with a welded steel prevention member to prevent the monopile foundation from rolling. The mounting stand system according to feature 7.

9. The aforementioned offshore structure is a monopile foundation that supports an offshore wind turbine, and is a monopile foundation in an erected state. Each of the aforementioned yard mounting platform and the aforementioned shipboard mounting platform includes a beam, The mounting stand system according to any one of claims 1 to 4.

10. A method for moving an offshore structure using the mounting platform system according to any one of claims 1, 2, and 4, The setup step involves placing the aforementioned shipboard mounting platform on the ship, Installation step: Installing the offshore structure, which is to be installed on the yard installation platform, onto the shipboard installation platform that is positioned in the aforementioned arrangement step, A method of movement characterized by comprising:

11. A method for moving the offshore structure using the mounting platform system described in claim 3, A moving step for moving the offshore structure, together with the yard mounting platform, onto the ship. A method of movement characterized by including

12. The aforementioned movement step is, The aforementioned offshore structure, along with the aforementioned yard mounting platform, is jacked up using a jacking step, A mounting step for placing the offshore structure and the yard installation platform, which are jacked up in the jack-up step, onto the skid beam, The method of movement according to claim 11, characterized by including the following:

13. A system comprising a first mounting platform system on which a bottom-fixed foundation supporting an offshore wind turbine is installed, and a second mounting platform system on which a jacket-type structure is installed, The first mounting base system is The aforementioned fixed-bottom foundation is installed, and a first yard installation platform is placed in the yard, The aforementioned fixed-bottom foundation is installed, and the first onboard mounting platform is placed on the ship, Includes, The second mounting base system is The base of the aforementioned jacket-type structure is installed, and a second yard installation platform is placed in the yard, The base of the aforementioned jacket-type structure is installed on a second onboard mounting platform which is placed on the ship, Includes, The aforementioned mounting platform for the first yard is made of steel. The aforementioned second yard mounting platform is made of steel, and structural steel is used. A system characterized by the following features.

14. A system comprising a first mounting platform system on which a bottom-fixed foundation supporting an offshore wind turbine is installed, and a second mounting platform system on which a jacket-type structure is installed, The first mounting base system is The aforementioned fixed-bottom foundation is installed, and a first yard installation platform is placed in the yard, The aforementioned fixed-bottom foundation is installed, and the first onboard mounting platform is placed on the ship, Includes, The second mounting base system is The base of the aforementioned jacket-type structure is installed, and a second yard installation platform is placed in the yard, The base of the aforementioned jacket-type structure is installed on a second onboard mounting platform which is placed on the ship, Includes, The aforementioned mounting platform for the first yard is made of steel. The first yard mounting platform and the first shipboard mounting platform are the same, The second yard mounting platform and the second shipboard mounting platform are different. A system characterized by the following features.

15. A system comprising a first mounting platform system on which a bottom-fixed foundation supporting an offshore wind turbine is installed, and a second mounting platform system on which a jacket-type structure is installed, The first mounting base system is The aforementioned fixed-bottom foundation is installed, and a first yard installation platform is placed in the yard, The aforementioned fixed-bottom foundation is installed, and the first onboard mounting platform is placed on the ship, Includes, The second mounting base system is The base of the aforementioned jacket-type structure is installed, and a second yard installation platform is placed in the yard, The base of the aforementioned jacket-type structure is installed on a second onboard mounting platform which is placed on the ship, Includes, The aforementioned mounting platform for the first yard is made of steel. The first yard mounting platform and the first shipboard mounting platform are the same, The second yard mounting platform and the second shipboard mounting platform are the same. A system characterized by the following features.

16. A system comprising a first mounting platform system on which a bottom-fixed foundation supporting an offshore wind turbine is installed, and a second mounting platform system on which a jacket-type structure is installed, The first mounting base system is The aforementioned fixed-bottom foundation is installed, and a first yard installation platform is placed in the yard, The aforementioned fixed-bottom foundation is installed, and the first onboard mounting platform is placed on the ship, Includes, The second mounting base system is The base of the aforementioned jacket-type structure is installed, and a second yard installation platform is placed in the yard, The base of the aforementioned jacket-type structure is installed on a second onboard mounting platform which is placed on the ship, Includes, The aforementioned mounting platform for the first yard is made of steel. The second yard mounting platform and the second shipboard mounting platform include those common to multiple bases and those individual to each base. A system characterized by the following features.

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