Floating structures, mooring systems, and mooring methods

Abstract

Reduces wear between the mooring line and the fastening member. [Solution] The floating structure 2 comprises a floating body 20, a cylindrical body 5, and a fastening member 6. The floating body floats on the water surface 91. The cylindrical body 5 extends upward from the bottom surface 211 of the floating body 20 located in the water. The fastening member 6 is provided above or inside the cylindrical body 5. The mooring line 4 is connected to the fastening member 6 via an opening at the lower end of the cylindrical body 5. As a result, the mooring line 4 is suspended via the cylindrical body 5, limiting the range in which the mooring line 4 can move freely at the mooring point, which is the connection point between the fastening member 6 and the mooring line 4, and reducing the range of swing of the mooring line 4 at the mooring point. As a result, sliding motion occurring at the mooring point can be suppressed, and wear between the mooring line 4 and the fastening member 6 can be reduced.

Description

Technical Field

[0001] The present invention relates to a floating structure moored by a mooring line.

Background Art

[0002] Conventionally, floating structures floating on the sea surface such as buoys and floating fish reefs are moored to the seabed by mooring lines. For example, in Patent Document 1, a floating structure is disclosed that includes two floating body main bodies extending in the front-rear direction, an upper connecting portion that connects the upper portions of the two floating body main bodies, and a mooring portion that is connected to the two floating body main bodies below the upper connecting portion and to which a mooring line is connected.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] By the way, in floating structures such as those in Patent Document 1, forces act on the floating structure from various directions due to waves, tidal currents, wind, etc., causing pitching and rolling, so a strong sliding motion occurs at the floating body mooring point (hereinafter, also simply referred to as the "mooring point"), which is the connection position between the mooring line and the floating structure, and there is a risk of wear between the fastening member and the mooring line at the mooring point. <�

[0005] The present invention has been made in view of the above problems, and aims to suppress the sliding motion at the mooring point and reduce the wear at the mooring point.

Means for Solving the Problems

[0006] One aspect of the present invention is a floating structure that floats on the water surface, comprising: a floating body; a cylindrical body extending upward from the bottom surface of the floating body located in the water; and a fastening member provided above or inside the cylindrical body, to which a mooring line is connected via an opening at the lower end of the cylindrical body.

[0007] A second aspect of the present invention is a floating structure according to aspect 1, further comprising: another cylindrical body extending upward from the bottom surface or another bottom surface of the floating body located underwater; and another fastening member provided above or inside the other cylindrical body, to which another mooring line is connected via an opening at the lower end of the other cylindrical body.

[0008] A third aspect of the present invention is a floating structure according to aspect 2, wherein the floating body comprises two floating sections arranged perpendicular to the front-rear direction parallel to the water surface and in a width direction parallel to the water surface, each extending in the front-rear direction, and an upper connecting section connecting the upper parts of the two floating sections above the water surface, wherein the cylindrical body is disposed inside one of the two floating sections, and the other cylindrical body is disposed inside the other of the two floating sections.

[0009] Aspect 4 of the present invention is a mooring system comprising a floating structure according to aspect 2 or 3, the mooring line and the other mooring line, a mooring base fixed to the seabed, the lower end of the upper mooring line which is the upper part of the mooring line and the lower end of the other upper mooring line which is the upper part of the other mooring line, all connected by a connecting member, and the connecting member and the mooring base being connected by a lower mooring line which is a common part of the mooring line and the other mooring line.

[0010] Aspect 5 of the present invention is a floating structure according to Aspect 1 (which may be any one of Aspects 1 to 3), wherein the retaining member is located above the water surface.

[0011] Aspect 6 of the present invention is a floating structure according to aspect 5, further comprising a closing member that together with the cylindrical body and the water surface forms a sealed space, wherein the retaining member is located within the sealed space.

[0012] Aspect 7 of the present invention is a floating structure according to aspect 6, wherein the sealed space is filled with an inert gas.

[0013] Aspect 8 of the present invention is a floating structure according to aspect 7, further comprising a check valve provided between the sealed space and the external space and used for injecting an inert gas into the sealed space.

[0014] Aspect 9 of the present invention is a method for mooring a floating structure comprising a floating body, a cylindrical body extending upward from the bottom surface of the floating body located in water, and a fastening member, the method comprising the steps of connecting a mooring line to the fastening member and guiding the mooring line into the interior of the cylindrical body so that the mooring line is connected to a fastening member located above or inside the cylindrical body via an opening at the lower end of the cylindrical body. [Effects of the Invention]

[0015] This invention makes it possible to reduce wear between the mooring line and the fastening member. [Brief explanation of the drawing]

[0016] [Figure 1] This is a side view of the mooring system according to the first embodiment. [Figure 2] This is a side view showing a floating structure. [Figure 3] This is a plan view showing a floating structure. [Figure 4] This is a front view showing a floating structure. [Figure 5] This is a cross-sectional view of the area around the mooring point of the floating structure. [Figure 6] This is a cross-sectional view of the area around the mooring point of another floating structure. [Figure 7] This diagram shows the process of mooring a floating structure. [Figure 8] This is a cross-sectional view of the area around the mooring point of another floating structure. [Figure 9] This is a cross-sectional view of the area around the mooring point of another floating structure. [Figure 10] This is a cross-sectional view showing the bottom of another floating structure. [Figure 11] It is a front view showing another floating structure.

Mode for Carrying Out the Invention

[0017] FIG. 1 is a side view showing the configuration of a mooring system 1 including a floating structure 2 according to a first embodiment of the present invention. The mooring system 1 includes a floating structure 2, a mooring base 3, and a mooring line 4. The mooring line 4 is also called a “mooring cable”. The mooring system 1 is a system for mooring a floating structure 2 floating on the water surface 91 to the seabed 92 by the mooring line 4. The floating structure 2 is a structure that floats on the water surface 91 in a state of being spaced upward from the seabed 92. When the floating structure 2 is installed at sea, the water surface 91 and the seabed 92 are the sea surface and the seabed, respectively. The floating structure 2 is, for example, an observation buoy moored in a predetermined sea area to observe tsunamis and / or waves. The overall length of the floating structure 2 is, for example, several meters to a dozen or so meters, the overall width of the floating structure 2 is, for example, several meters, and the height of the floating structure 2 is, for example, several meters. Also, the water surface 91 is located around the center in the height direction of the floating structure 2.

[0018] The mooring base 3 is an object fixed to the seabed 92. Here, “fixed” means a state of not moving under forces within the assumed range. The mooring base 3 is, for example, a sinker (i.e., a weight) or an anchor (i.e., an anchor having a holding force) sunk into the seabed 92. Alternatively, the mooring base 3 may be a fixed structure pre-installed on the seabed 92. The mooring base 3 does not necessarily have to be directly fixed to the seabed 92, and may be an object indirectly fixed to the seabed 92 in the water through, for example, another structure fixed to the seabed 92.

[0019] The mooring line 4 is a substantially linear member that connects the floating structure 2 and the mooring base 3. As shown in Figure 4, which illustrates the floating structure 2 described later, it has a structure in which two upper mooring lines 41 and a lower mooring line 42 are connected by a connecting member 7. The mooring line 4 is, for example, a metal chain. Alternatively, the mooring line 4 may be a mooring rope, or a chain and a mooring rope may be connected. The mooring rope is, for example, a rope made of synthetic fiber or metal. In Figure 1, for illustrative purposes, the mooring line 4 is shown as a line.

[0020] In the example shown in Figure 1, the floating structure 2 is moored at two points to the mooring base 3 by mooring lines 4. That is, the floating structure 2 is connected to each of the two upper mooring lines 41.

[0021] Figure 2 is a side view showing the floating structure 2. Figure 3 is a top view showing the floating structure 2. Figure 4 is a front view showing the floating structure 2. In Figures 2 to 4, three mutually orthogonal directions, the X, Y, and Z directions, are defined. The X and Y directions are parallel to the horizontal plane, and the Z direction is parallel to the direction of gravity. The floating structure 2 is a so-called catamaran (twin-hulled) type structure. The floating structure 2 comprises a floating body 20 that floats on the water surface 91 and a superstructure 23 provided on the floating body 20. The floating body 20 comprises two floating sections 21 and an upper connecting section 22.

[0022] Each floating section 21 extends approximately parallel to the X direction in Figures 2 to 4 (hereinafter referred to as the "front-rear direction"). The two floating sections 21 are arranged with a gap between them in the width direction perpendicular to the front-rear direction parallel to the water surface 91 (i.e., the Y direction in Figures 2 to 4). In other words, one floating section 21 is positioned to the side of the other floating section 21, spaced apart. Hereafter, when distinguishing between the two floating sections 21, the floating section 21 located on the left side (+Y side) when facing forward on the floating structure 2 will be called the "left floating section 21," and the floating section 21 located on the right side (-Y side) will be called the "right floating section 21." The shape of the two floating sections 21 extends in the front-rear direction at the center of the width direction of each floating section 21 and is approximately symmetrical with respect to a plane of symmetry perpendicular to the width direction. The floating body 20 is formed from, for example, stainless steel, aluminum alloy, FRP, etc.

[0023] Since the shapes of the two floating body sections 21 are almost identical, the shape of one of the floating body sections 21 will be described below. The floating body section 21 is a member that extends elongated in the front-rear direction and tapers towards the front end (a so-called boat shape). In the floating structure 2 illustrated in Figure 3, the floating body section 21 also tapers towards the rear end. This tapering shape includes a shape in which the width in the width direction of the floating body section 21 gradually decreases towards the front or rear end. The width in the width direction of the floating body section 21 (hereinafter also simply referred to as "width") is maximum at the center in the front-rear direction. In the floating body section 21, the part with the maximum width in a plan view extends for a certain length in the longitudinal direction (i.e., the front-rear direction). The central part of the floating body section 21 is a parallel section in which parts with the same cross-sectional shape perpendicular to the front-rear direction are continuous in the longitudinal direction. By providing this parallel section, the manufacturing of the floating body section 21 can be simplified.

[0024] At the front end of the floating body 21, which extends forward from the central part, the width gradually decreases as it approaches the front end. At the rear end of the floating body 21, which extends backward from the central part, the width gradually decreases as it approaches the rear end. The shape of the floating body 21 is, for example, substantially symmetrical with respect to a plane of symmetry perpendicular to the front-to-back direction at the center in the front-to-back direction (i.e., substantially front-to-back symmetrical). In addition, the length in the front-to-back direction of the part of the floating body 21 that has the maximum width in a plan view may be approximately 0 m.

[0025] At the center of the floating body 21 in the front-rear direction, the lower end (i.e., bottom) of the floating body 21 has a shape in which a plane substantially perpendicular to the vertical direction (i.e., the Z direction) is provided in the center in the width direction. The shape of the lower ends of the two floating body 21 can be changed in various ways, such as a rounded U-shape or a V-shape with a pointed lower end. In addition, the shape of parts other than the lower ends of the floating body 21 can also be changed in various ways.

[0026] The upper connecting section 22 connects the upper parts of the two floating body sections 21 above the water surface 91. In the examples shown in Figures 2 to 4, the upper connecting section 22 is an upper deck connecting the upper ends (i.e., the (+Z) side ends) of the two floating body sections 21, and is hereinafter also referred to as the "upper deck 22". The upper deck 22 is a substantially flat plate-shaped member that is substantially vertical in the vertical direction and is positioned above the water surface 91. The upper deck 22 is, for example, a substantially rectangular member that extends over the entire length of the two floating body sections 21 in the front-rear direction. The upper deck 22 covers the entire upper surface of the two floating body sections 21 and the entire space above the two floating body sections 21. The upper deck 22 does not necessarily have to be substantially rectangular and may be a member of other shapes (for example, substantially disc-shaped). The upper deck 22 is formed from, for example, stainless steel, aluminum alloy, FRP, etc.

[0027] On the upper deck 22, various equipment and facilities are arranged as the superstructure 23, according to the intended use of the floating structure 2. As mentioned above, when the floating structure 2 is used as an observation buoy to observe tsunamis and waves, for example, a GPS (Global Positioning System) receiver 231 is installed on the superstructure 23 to acquire the three-dimensional movement of the floating structure 2. Then, based on the movement of the floating structure 2 acquired by the GPS receiver 231, fluctuations in the water surface 91 (e.g., waves, tide level, tsunami, etc.) are determined.

[0028] Furthermore, solar panels may be installed on the upper deck 22 to supply power to, for example, a GPS receiver 231. Since the floating structure 2 is of the catamaran type, the area of ​​the upper deck 22 can be made relatively large, allowing the solar panels to be arranged almost horizontally. This increases the amount of power generated by the solar panels. It also reduces the wind pressure resistance of the solar panels. As a result, the mooring tension acting on the mooring line 4 can be reduced.

[0029] The floating structure 2 may be provided with other connecting members in addition to, or instead of, the upper deck 22 which is the upper connecting part. These other connecting members may be, for example, a truss structure formed by combining substantially straight steel members. Furthermore, the upper connecting part does not completely fix the relative positions of the two floating sections 21, but may be a structure that allows for some degree of variation in the relative positions of the two floating sections 21.

[0030] As shown in Figures 2 to 4, the floating structure 2 has cylindrical bodies 5 within each floating section 21. The cylindrical bodies 5 extend upward from the bottom surface 211 of the floating section 21. That is, the cylindrical body 5 of the left floating section 21 extends upward from the bottom surface 211 located in the water of the floating body 20 (left floating section 21) and penetrates the interior of the floating body 20 (left floating section 21). The other cylindrical body 5 of the right floating section 21 extends upward from the other bottom surface 211 located in the water of the floating body 20 (right floating section 21) and penetrates the interior of the floating body 20 (right floating section 21). Hereafter, when distinguishing between the two cylindrical bodies 5, the cylindrical body 5 provided in the left floating section 21 will be called the "left cylindrical body 5," and the cylindrical body 5 provided in the right floating section 21 will be called the "right cylindrical body 5." The cylindrical body 5 is a substantially cylindrical member that has an opening at least at its lower end, is positioned inside the floating body section 21, and extends vertically. The height of the cylindrical body 5 is, for example, several meters. By placing the cylindrical body 5 inside the floating body section 21 (floating body main body 20), the cylindrical body 5 is prevented from being directly subjected to forces from wind and currents, and the mooring tension on the floating structure 2 can be reduced.

[0031] As shown in Figures 2 to 4, the floating structure 2 further includes two fastening members 6. The fastening member 6 of the left floating section 21 is located above the left cylindrical body 5, and the mooring line 4 (specifically the upper mooring line 41) is connected to it via an opening at the lower end of the left cylindrical body 5. The other fastening member 6 of the right floating section 21 is located above the right cylindrical body 5, and the mooring line 4 (specifically the upper mooring line 41) is connected to it via an opening at the lower end of the right cylindrical body 5. Here, "via the opening at the lower end" means that the mooring line 4 extends downward from the fastening member 6 inside the cylindrical body 5 and extends outside the cylindrical body 5 from the opening at the lower end of the cylindrical body 5. Because the floating structure 2 has multiple mooring points, the mooring tension acting on the upper mooring line 41 (per line) can be reduced. Figure 5 is a cross-sectional view of the area around the mooring point of the right floating section 21 of the floating structure 2, cut by a plane perpendicular to the X direction. In the example shown in Figure 5, the fastening member 6 provided on the right floating body 21 has a harp shackle 61 and a shackle pin 62, and is located vertically above the right cylindrical body 5.

[0032] The harp shackle 61 is a roughly U-shaped shackle, and a shackle pin 62 passes through its lower end (the end of the U). The shackle pin 62 is inserted into one hole of the harp shackle 61 and secured by screwing it into a threaded hole provided in the other hole. The harp shackle 61 and shackle pin 62 are made of, for example, stainless steel, iron, or aluminum. The fastening member 6 is placed on a washer 63 located on the upper deck 22. The shackle pin 62 is connected to the mooring ring (the hole through which the shackle pin 62 passes), which is the end of the upper mooring line 41, at the mooring point, thereby connecting the fastening member 6 and the mooring line 4. Preferably, the fastening member 6 has an outer diameter larger than the inner diameter of the cylindrical body 5. This prevents the fastening member 6 from falling into the cylindrical body 5.

[0033] The mooring structure near the fastening member 6 in the right floating body section 21 (hereinafter referred to as the "mooring structure") is the same in the left floating body section 21.

[0034] As shown in Figures 1 and 4, in the mooring system 1, the lower ends of the two upper mooring lines 41 and the upper ends of the lower mooring line 42 are connected by a connecting member 7. In this way, the upper mooring line 41 and the lower mooring line 42 connected to the left floating body 21 constitute one mooring line 4, the upper mooring line 41 and the lower mooring line 42 connected to the right floating body 21 constitute another mooring line 4, and the lower mooring line 42 is the common part of the two mooring lines 4. That is, the lower end of the upper mooring line 41, which is the upper part of one mooring line 4, and the lower end of the other upper mooring line 41, which is the upper part of the other mooring line 4, are connected by a connecting member 7, and the connecting member 7 and the mooring base 3 are connected by the lower mooring line 42, which is the common part of the mooring line 4 and the other mooring line 4. The connecting member 7 is, for example, a suspension piece that connects the two upper mooring lines 41 and the lower mooring line 42 in a Y shape. The connecting member 7 is located at a water depth of several tens of meters.

[0035] The connection between the two upper mooring lines 41 and the lower mooring line 42 by the connecting member 7 suppresses the rolling of the floating structure 2 when external forces such as waves, currents, and wind act on the floating structure 2. In the mooring system 1, there may be no other upper mooring lines 41 (i.e., only one mooring line 4 may be provided), or there may be three or more upper mooring lines 41. Also, there may be multiple lower mooring lines 42. The connecting member 7 may not be provided on the mooring line 4. In this case, multiple mooring lines 4 may be connected to the mooring base 3 (or each of the multiple mooring bases 3).

[0036] In Figures 2 to 4, the upper end of the cylindrical body 5 is located above the water surface 91, and the lower end is located below the water surface 91. Furthermore, since the cylindrical body 5 has an opening at its lower end and is located inside the floating body 21, the water surface 91 also exists inside it.

[0037] In the mooring system 1 shown in Figure 1, when external forces such as waves, currents, and wind act on the floating structure 2, the floating structure 2 swings around the mooring base 3 (or the end of the mooring line 4 that is in contact with the seabed 92 and is opposite to the mooring base 3), and is positioned on the downstream side in the direction in which the external force acts (hereinafter also referred to as the "direction of the external force"). When the floating structure 2 swings around the mooring base 3, a large mooring force acts on the mooring point of the floating structure 2.

[0038] On the other hand, as described above, the floating structure 2 comprises a floating body 20, a cylindrical body 5 extending upward from the bottom surface 211 of the floating body 20 located in the water, and a fastening member 6 provided above the cylindrical body 5, to which the mooring line 4 is connected via an opening at the lower end of the cylindrical body 5. Since the mooring line 4 is suspended via the cylindrical body 5, the range in which the mooring line 4 can move freely at the mooring point, which is the connection point between the fastening member 6 and the mooring line 4, is restricted, and the range of swing of the mooring line 4 at the mooring point is reduced. As a result, sliding motion occurring at the mooring point is suppressed, and wear between the mooring line 4 and the fastening member 6 at the mooring point can be reduced. In addition, since the mooring line 4 is located inside the cylindrical body 5 near the mooring point, it is possible to suppress the mooring line 4 from being subjected to impacts from waves, etc.

[0039] In the mooring system 1, the lower end of the upper mooring line 41, which is the upper part of mooring line 4, and the lower end of another upper mooring line 41, which is the upper part of another mooring line 4, are connected by a connecting member 7, and the connecting member 7 and the mooring base 3 are connected by the lower mooring line 42, which is the common part of mooring line 4 and other mooring lines 4. This makes it possible to distribute and reduce the force acting on the mooring point, and also reduces wear between the mooring line 4 and the fastening member 6, i.e., wear at the mooring point.

[0040] Furthermore, even when the floating structure 2 is moored by two independent mooring lines 4 without using a connecting member 7, the presence of two mooring points allows the mooring tension acting on the mooring lines 4 to be distributed, thereby reducing the overall mooring tension.

[0041] As described above, the floating structure 2 comprises a floating body 20 which is arranged perpendicular to the front-to-back direction parallel to the water surface 91 and in a width direction parallel to the water surface 91, and each floating section 21 extends in the front-to-back direction, and an upper connecting section 22 which connects the upper parts of the two floating sections 21 above the water surface 91, with one cylindrical body 5 positioned inside one of the two floating sections 21 and the other cylindrical body 5 positioned inside the other floating section 21. This makes it possible to reduce the force acting on each mooring point while maintaining the overall balance of the floating structure 2.

[0042] In the floating structure 2, since the fastening member 6 is located above the water surface 91, the connection work between the floating section 21 and the mooring base 3 can be easily carried out. In addition, since the mooring point where a large mooring tension is applied is located above the water surface 91, corrosion of the mooring line 4 at the mooring point can be suppressed.

[0043] Next, a floating structure 2 according to a second embodiment of the present invention will be described. Figure 6 is an enlarged cross-sectional view showing the area around the mooring point of the floating structure 2, and corresponds to Figure 5. The floating structure 2 has the same structure as the floating structure 2 shown in Figures 2 to 5, except that it further comprises a closing member 8. The mooring system 1 is the same as in Figure 1, except that the structure of the floating structure 2 is different (the same applies to the other floating structures 2 described below).

[0044] The floating structure 2 shown in Figure 6 further comprises a closing member 8 that, together with the cylindrical body 5 and the water surface 91 (see Figure 4), forms a sealed space 80. The closing member 8 comprises a box body 81, a check valve 82, and a cap 83. The box body 81 is fixed to the floating body 20 by bolts, welding, or the like. The box body 81 is located above the cylindrical body 5 and covers the entire fastening member 6. The box body 81 is made of, for example, stainless steel, aluminum alloy, FRP, or the like.

[0045] Since a water surface 91 exists inside the cylindrical body 5, a sealed space 80 is formed by the box body 81, the cylindrical body 5, and the water surface 91, maintaining an airtight structure. In other words, the inside of the box body 81 is a sealed space 80, and the flow of air between it and the outside space is blocked. The fastening member 6 is located inside the sealed space 80.

[0046] It is preferable that an inert gas, such as nitrogen gas, be injected into the sealed space 80. By filling the inside of the box 81 with an inert gas, oxygen, which causes corrosion, is removed from inside the sealed space 80. This reduces the progression of deterioration due to corrosion of the fastening members 6 and mooring lines 4 inside the sealed space 80. For example, argon gas may be used as the inert gas.

[0047] It is preferable to install a pressure gauge in the sealed space 80 so that the pressure inside the sealed space 80 can be measured when an inert gas is injected into the sealed space 80. The pressure gauge is used to ensure that the pressure inside the sealed space 80 does not exceed a predetermined pressure (for example, a gauge pressure of 10 kPa).

[0048] Since the injected inert gas may dissolve into the water, the inert gas is reinjected during periodic inspections. This removes oxygen from within the sealed space 80, thereby reducing the progression of deterioration of the mooring line 4 due to corrosion within the sealed space 80.

[0049] A check valve 82 is installed in the enclosure 81 at a location that serves as the gas inlet. The check valve 82 is attached to piping connected to the enclosure 81 to prevent air from flowing from the outside space into the sealed space 80. For example, a nipple-shaped check valve 82 is used. The check valve 82 may be installed in a location other than the enclosure 81, for example, on a pipe connecting the sealed space 80 and the outside space, as long as it is provided between the sealed space 80 and the outside space and can be used for injecting inert gas into the sealed space 80.

[0050] Furthermore, it is preferable to attach a cap 83, such as a plug, to the gas inlet. The cap 83 is attached to the end of the piping connected to the box body 81 to prevent the check valve 82 from becoming dirty and to prevent air from flowing into the sealed space 80 from the outside space. For example, plastic, vinyl, silicone, etc., can be used for the cap 83.

[0051] As explained above, in the floating structure 2 of Figure 6, a sealed space 80 is formed by the closing member 8, which suppresses the inflow of oxygen from the outside and reduces the progression of deterioration due to corrosion of the fastening member 6 and mooring line 4.

[0052] Figure 7 shows the flow of mooring the floating structure 2, including the connection between the floating structure 2 and the mooring line 4, and the injection of gas into the enclosed space 80. First, the floating structure 2 is assembled on land by attaching cylindrical bodies 5 and the like to the floating body 20. Next, the floating body 20 is loaded onto a barge (or crane ship) and transported to the installation area in the ocean (step S11). The floating structure 2 may also be towed to the installation area by being pulled by a barge with ropes or the like.

[0053] Next, the mooring line 4 is connected to the fastening member 6 (step S12). Specifically, the shackle pin 62 is inserted into the end of the upper mooring line 41, and the shackle pin 62 is fixed to the harp shackle 61.

[0054] Next, the mooring line 4 is guided into the interior of the cylindrical body 5 provided in the floating body 20 (step S13). At this time, the mooring line 4 (more precisely, the upper mooring line 41) may be guided into the interior of the cylindrical body 5 from above the cylindrical body 5, or the mooring line 4 may be guided into the interior of the cylindrical body 5 from below the cylindrical body 5. In this embodiment, since the fastening member 6 is larger than the inner diameter of the cylindrical body 5, the upper mooring line 41 is lifted up together with the fastening member 6 using a crane, and the upper mooring line 41 is inserted into the cylindrical body 5 from above the cylindrical body 5. As a result, the mooring line 4 (specifically the upper mooring line 41) is connected to the fastening member 6 located above the cylindrical body 5 (in the interior of the cylindrical body 5 in Figure 9, which will be described later) via the opening at the lower end of the cylindrical body 5. Steps S12 and S13 may be performed in any order. Steps S12 and S13 are performed for the left floating body section 21 and the right floating body section 21, respectively.

[0055] Next, the mooring line 4 and the mooring base 3 are connected (step S14). In this embodiment, a connecting member 7 is used, so the two upper mooring lines 41 and the one lower mooring line 42 are connected by the connecting member 7, and then the lower mooring line 42 is connected to the mooring base 3. After connecting the mooring line 4 and the mooring base 3, the upper mooring line 41 of the mooring line 4 may be guided into the inside of the cylindrical body 5 provided on the floating body 20, and the mooring line 4 may be connected to the fastening member 6. Also, steps S12 to S14 may be performed before step S11.

[0056] Next, the mooring base 3 is brought down to the seabed 92 (step S15). The mooring base 3 is deployed from the barge using a winch and brought down to the seabed 92. After confirming that the mooring base 3 has come down to the seabed 92, the floating structure 2 is installed on the open sea (step S16).

[0057] Next, a closing member 8 is attached to the floating structure 2 to form a sealed space 80, and the sealed space 80 is filled with inert gas (step S17). The closing member 8 may be attached at any stage after step S13.

[0058] Furthermore, after attaching the cylindrical body 5 to the floating body 20, the closing member 8 may be temporarily installed, and a leak test may be performed in advance to confirm that a sealed space is formed by the closing member 8. The leak test is preferably performed before step S11. In the leak test, the opening at the lower end of the cylindrical body 5 is closed with a lid or the like, and the inside of the closing member 8 is prepared to become a sealed space. Next, the presence or absence of leaks is checked by filling the closing member 8 with gas through the gas inlet provided in it. After that, the lid or the like that that closed the lower end of the cylindrical body 5 and the closing member 8 are removed, and the process proceeds to step S11. If it is desired to check for air leaks in the permanently installed closing member 8, the leak test may be performed after step S17.

[0059] The above description shows a general example of the installation of a floating structure 2 having a closing member 8 in the mooring system 1. In the first embodiment, the floating structure 2 is installed on the water by the work of steps S11 to S16.

[0060] Next, a floating structure 2 according to a third embodiment of the present invention will be described. Figure 8 is an enlarged cross-sectional view showing the area around the mooring point of the floating structure 2, and corresponds to Figure 5. The floating structure 2 has the same structure as the floating structure 2 shown in Figures 2 to 5, except that the configuration and arrangement of the fastening members 6 are different.

[0061] In the example shown in Figure 8, a roughly U-shaped fastening member 6 is attached to the top surface of the box body 81, which is the closing member 8. The connection between the fastening member 6 and the mooring line 4 is made on land by passing the fastening member 6 through the mooring line 4 and then fixing the fastening member 6 to the box body 81. In this way, the fastening member 6 is indirectly fixed to the floating body 20 via the box body 81. In Figure 8, the box body 81, together with the cylindrical body 5 and the water surface 91 (see Figure 4), forms a sealed space 80, and the fastening member 6 is located within the sealed space 80. Since the box body 81 is sufficiently larger than the inner diameter of the cylindrical body 5, the fastening member 6 will not fall into the cylindrical body 5 once it is fixed to the box body 81. The fastening member 6 may also be attached to the inner surface of the box body 81. Preferably, an inert gas such as nitrogen gas is injected into the sealed space 80, and at this time, as in the second embodiment, a check valve is provided between the sealed space 80 and the external space and used for injecting the inert gas into the sealed space 80 (the same applies to the sealed space 80 in the other embodiments described below).

[0062] Next, a floating structure 2 according to a fourth embodiment of the present invention will be described. Figure 9 is an enlarged cross-sectional view showing the area around the mooring point of the floating structure 2, and corresponds to Figure 5. The floating structure 2 has the same structure as the floating structure 2 shown in Figures 2 to 6, except that the configuration and arrangement of the cylindrical body 5, fastening member 6, closing member 8, etc. are different.

[0063] In the example shown in Figure 9, a roughly U-shaped fastening member 6 is attached to the inner side of the cylindrical body 5. The closing member 8 is a plate-shaped cover provided at the same height as the upper deck 22. In this case, the mooring line 4 can be attached to the floating body 20 without placing any structures on the upper deck 22. The fastening member 6 may also be fixed to the cover, which is the closing member 8. In Figure 9, the closing member 8, together with the cylindrical body 5 and the water surface 91 (see Figure 4), forms a sealed space 80, and the fastening member 6 is located within the sealed space 80. The fastening member 6 may be provided inside the cylindrical body 5 in various configurations. In addition, a protruding member (not shown) of a predetermined size may be provided at the bottom of the fastening member 6 on the inner side of the cylindrical body 5. In this case, it is prevented that the fastening member will fall out of the bottom of the cylindrical body 5.

[0064] The lid, which is the closing member 8, does not necessarily have to be at the same height as the upper deck 22, and may be located inside the cylindrical body 5. Furthermore, the lid may be integrated with the floating body 20 or it may be detachable from the floating body 20. The lid may be made of, for example, stainless steel, aluminum alloy, FRP, etc.

[0065] Figure 10 is an enlarged cross-sectional view showing the bottom of the floating body 20 (for example, the right floating section 21) of another floating structure 2, and shows a cross-section perpendicular to the X direction. In the example in Figure 10, the lower end of the cylindrical body 5 protrudes below the bottom surface 211 of the floating body 20, and the opening at the lower end of the cylindrical body 5 is located below the bottom surface 211. The amount of protrusion of the cylindrical body 5 from the bottom surface 211 is greater than 0% of the total length of the cylindrical body 5 and less than a few percent. Thus, the opening at the lower end of the cylindrical body 5 does not necessarily have to be provided on the bottom surface 211 of the floating body 20.

[0066] Next, a floating structure 2 according to a fifth embodiment of the present invention will be described. Figure 11 is a front view showing the floating structure 2.

[0067] The floating structure 2 shown in Figure 11 comprises a substantially cylindrical floating body 20 and an upper structure 23 provided on the floating body 20. The cylindrical body 5 is provided at the center of the floating body 20, and there is one mooring line 4, so the floating structure 2 is moored at one point. The structure of the mooring point of the floating structure 2 is the same as in the first embodiment, and structures of other embodiments may also be adopted. That is, the mooring line 4 is guided into the cylindrical body 5, and the fastening member 6 and the mooring line 4 are connected above or inside the cylindrical body 5. Also, except for the single mooring point and the structure of the floating structure 2, the mooring system 1 is the same as in Figure 1.

[0068] Various modifications are possible to the floating structure 2 described above.

[0069] The structure of the floating structure 2 and the mooring system 1 described above can be widely applied not only to observation buoys for observing tsunamis and waves, but also to various floating structures on the water surface such as floating docks, floating breakwaters, floating artificial reefs, and offshore floats.

[0070] The floating body 20, which is the part of the floating structure 2 that obtains buoyancy, is not limited to catamaran or cylindrical shapes, but may also be single-hull, multi-hull, or box-shaped, such as a rectangular parallelepiped.

[0071] In the floating structure 2, there may be one floating section 21 or three or more. For example, three floating sections 21 arranged in the width direction may be provided in the floating structure 2. Also, the size and shape of the multiple floating sections 21 may be the same or different. For example, if three floating sections 21 are provided, the length in the front-to-back direction of the floating section 21 located in the center in the width direction may be longer than the lengths of the two floating sections 21 located on either side in the width direction.

[0072] The mooring structure in the left floating body section 21 is preferably the same as that in the right floating body section 21, but it may be different. For example, a closing member 8 may be provided above the cylindrical body 5 in only one of the floating body sections 21. In either mooring structure, the fastening member 6 is provided above or inside the cylindrical body 5.

[0073] The cylindrical body 5 does not need to extend up to the upper deck 22, as long as it extends upward from the bottom surface of the floating body 20, nor does it need to extend above the upper deck 22. Even in this case, the presence of the cylindrical body 5 suppresses wear at the connection point between the fastening member 6 located above or inside the cylindrical body 5 and the mooring line 4. That is, the lower end of the cylindrical body 5 only needs to be located at or below the bottom surface, the upper end of the cylindrical body 5 only needs to be located above the bottom surface, and the length of the cylindrical body 5 only needs to be long enough to ensure that the mooring line 4 hangs down inside the cylindrical body 5. As a result, the mooring structure becomes one in which the mooring line 4 hangs down inside the cylindrical body 5, so that sliding between the mooring line 4 and the fastening member 6 is suppressed, and wear at the mooring point is reduced. The cylindrical body 5 may also be made up of multiple cylindrical elements arranged vertically.

[0074] The cylindrical body 5 may be placed on the floating structure 2 as a single unit, or as a unit of three or more units. In a catamaran buoy, the cylindrical body 5 may be placed on only one of the two floating sections 21 and the mooring line 4 may be connected to the floating section 21, or multiple cylindrical bodies 5 may be placed on only one floating section 21 and the mooring line 4 may be connected to each cylindrical body 5. Furthermore, the cylindrical body 5 is not limited to a cylindrical shape, but may also have a polygonal shape such as a rectangular parallelepiped.

[0075] In the example shown in Figure 11, when multiple sets of cylindrical bodies 5 and fastening members 6 are provided for multi-point mooring, the multiple cylindrical bodies 5 extend upward from the same bottom surface of the floating body 20 located in the water. On the other hand, as already explained, in the example of multi-point mooring shown in Figure 4, one cylindrical body 5 extends upward from one of the two bottom surfaces 211 of the two floating body parts 21 of the floating body 20, and the other cylindrical body 5 extends upward from the other bottom surface 211. Thus, the multiple cylindrical bodies 5 may extend upward from the same bottom surface or from different bottom surfaces. In either mooring structure, the cylindrical bodies 5 extend upward from the bottom surface 211 located in the water, the fastening members 6 are provided above or inside the cylindrical bodies 5, and the mooring line 4 is connected to the fastening members 6 via an opening at the lower end of the cylindrical body 5.

[0076] The fastening member 6 can be any member (fastener) that has the function of connecting to the mooring line 4, and other members such as eye bolts, eye nuts, eye plates, and hook receivers may be used. The harp shackle 61 may have an outer diameter smaller than the cylindrical body 5 and is not limited to a U shape but may also be twisted. The shackle pin 62 may be of a type that has its end fixed with a bolt or nut. The washer 63 may be substituted with a steel plate that is larger than the outer diameter of the cylindrical body 5. The fastening member 6 may be provided inside the cylindrical body 5 and below the water surface 91.

[0077] The connecting member 7 may also be other members such as a harp shackle, shackle pin, eye bolt, eye nut, eye plate, or hook receiving fitting.

[0078] The closing member 8 does not necessarily have to include a box 81, a check valve 82, and a cap 83. Furthermore, the box 81 only needs to have a structure that separates the inside from the outside; for example, it may be directly placed over the cylindrical body 5 as a lid. The closing member 8 may also have other shapes.

[0079] The configurations in the above embodiments and each modified example may be combined as appropriate, as long as they do not contradict each other. [Explanation of Symbols]

[0080] 1. Mooring System 2. Floating structures 3. Mooring base 4. Mooring lines 5 Cylinder 6. Fastening members 7 Connecting members 8 Closing member 20 Floating body 21 Floating section 22 Upper deck (upper connecting part) 41 Upper mooring line 42 Lower mooring line 80 Closed space 82 Check valve 91 Water surface 92 Underwater 211 Bottom S12, S13 Step

Claims

1. A floating structure that floats on the water surface, The floating body and A cylindrical body extending upward from the bottom surface of the floating body located in the water, A fastening member provided above or inside the cylindrical body, to which the mooring line is connected via an opening at the lower end of the cylindrical body, A floating structure equipped with [a specific feature / feature].

2. A floating structure according to claim 1, A cylindrical body extending upward from the bottom surface or another bottom surface of the floating body located in the water, An additional fastening member provided above or inside the other cylindrical body, to which another mooring line is connected via an opening at the lower end of the other cylindrical body, A floating structure that also possesses the following features.

3. A floating structure according to claim 2, The floating body is Two floating body sections are arranged perpendicular to the front-to-back direction parallel to the water surface and in a width direction parallel to the water surface, and each extends in the front-to-back direction, An upper connecting part that connects the upper parts of the two floating body parts above the water surface, Equipped with, A floating structure in which the cylindrical body is placed inside one of the two floating sections, and the other cylindrical body is placed inside the other of the two floating sections.

4. A mooring system, A floating structure according to claim 2 or 3, The aforementioned mooring line and the other mooring lines, A mooring base fixed to the bottom of the water, A mooring system in which the lower end of an upper mooring line, which is the upper part of the aforementioned mooring line, and the lower end of another upper mooring line, which is the upper part of the other mooring line, are connected by a connecting member, and the connecting member and the mooring base are connected by a lower mooring line, which is the common part of the aforementioned mooring line and the other mooring line.

5. A floating structure according to claim 1, The aforementioned fastening member is a floating structure located above the water surface.

6. A floating structure according to claim 5, The system further comprises a closing member that forms a sealed space together with the cylindrical body and the water surface, A floating structure in which the fastening member is located within the sealed space.

7. A floating structure according to claim 6, A floating structure in which the sealed space is filled with inert gas.

8. A floating structure according to claim 7, A floating structure further comprising a check valve provided between the sealed space and the external space, which is used for injecting an inert gas into the sealed space.

9. A method for mooring a floating structure comprising a floating body, a cylindrical body extending upward from the bottom surface of the floating body located in water, and a fastening member, The process of connecting the mooring line to the fastening member, The process involves guiding the mooring line into the interior of the cylindrical body, and connecting the mooring line to a fastening member located above or inside the cylindrical body via an opening at the lower end of the cylindrical body, A mooring method comprising:

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