Multi-function ship

Abstract

To provide a multi-purpose vessel that combines cost efficiency and maneuverability for the construction and maintenance of floating offshore wind power generation facilities. [Solution] The multi-purpose vessel can be switched between a survey mode with a scaffold attached to the deck, an anchor handling mode in which the anchor of an offshore wind power generation facility can be placed on the deck and the chain of the offshore wind power generation facility can be stored in the storage space below the deck and the anchor can be installed on the seabed and the chain can be extended, and a maintenance mode in which a gangway is attached to the deck.

Description

[Technical field]

[0001] The present invention relates to a multi-function vessel. [Background technology]

[0002] When constructing a floating offshore wind power generation facility as shown in Patent Document 1, a survey process, an anchor handling process, and a construction process are usually carried out. In the survey process, a ground survey of the seabed at the site where the floating offshore wind power generation facility is to be installed is carried out. In the anchor handling process, chains, anchors, etc. used in the construction of the floating offshore wind power generation facility are transported to the construction site, and the chains are stretched and the anchors are installed on the seabed. In the construction process, suction piles are dropped into the water, and the offshore wind power generation facility is fixed using the suction piles and anchors, etc.

[0003] After the floating offshore wind power generation facility is constructed, a process for maintaining and inspecting the facility (simply referred to as the maintenance process in this specification) is carried out. In the maintenance process, workers use a gangway provided on the ship to transfer to the floating offshore wind power generation facility and carry out work. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2020-163979 A Summary of the Invention [Problem to be solved by the invention]

[0005] To carry out the survey, anchor handling, construction, and maintenance processes, vessels with the appropriate functions for each process are required. For example, the survey process requires a vessel equipped with a yagura, and the anchor handling process requires a vessel with space to carry chains, anchors, etc. Additionally, the construction process requires a vessel equipped with a large construction crane that can drop suction piles into the water, and the maintenance process requires a vessel equipped with a gangway.

[0006] Here, if multiple dedicated ships with each of the above functions are prepared, the costs of acquiring and maintaining each dedicated ship will increase. Furthermore, during the period when the dedicated ships are not performing their respective processes, the dedicated ships will be idle and their operating rates will decrease. As a result, there is a problem that it becomes difficult to recover operating costs. In addition, in order to simultaneously install a yagura, storage space for chains, etc., a large construction crane, and a gangway on one ship, the hull of the ship will become excessively large, and maneuverability will be impaired.

[0007] The present invention has been made in consideration of the above circumstances, and aims to provide a multi-function ship that achieves both cost and maneuverability when constructing and maintaining floating offshore wind power generation facilities. [Means for solving the problem]

[0008] In order to solve the above problems, the multi-purpose vessel of aspect 1 of the present invention is capable of switching between a survey mode with a scaffold attached to the deck, an anchor handling mode in which the anchor of an offshore wind power generation facility can be placed on the deck and the chain of the offshore wind power generation facility can be stored in the storage space below the deck and the anchor can be installed on the seabed and the chain can be extended, and a maintenance mode in which a gangway is attached to the deck.

[0009] A second aspect of the present invention is a multi-function vessel according to the first aspect, wherein in the survey mode, the tower is provided above a moonpool that penetrates the vessel from top to bottom.

[0010] A third aspect of the present invention is a multi-purpose vessel according to the first or second aspect, wherein in the anchor handling mode, a non-watertight bottom cover is attached to the bottom of the moonpool that passes vertically through the hull.

[0011] A fourth aspect of the present invention is a multi-function ship according to any one of aspects 1 to 3, wherein, in the maintenance mode, an upper cover to which the gangway is fixed is positioned so as to cover the upper part of a moonpool that penetrates the hull vertically. Effect of the Invention

[0012] According to the multi-function ship according to the above aspect of the present invention, it is possible to achieve both cost and maneuverability in the construction and maintenance of a floating offshore wind power generation facility. [Brief description of the drawings]

[0013] [Figure 1] FIG. 2A is a cross-sectional view and FIG. 2B is a plan view of a multi-function vessel in survey mode according to an embodiment of the present invention. [Diagram 2] FIG. 2(a) is a cross-sectional view, and FIG. 2(b) is a plan view of a multi-purpose vessel in anchor handling mode according to an embodiment of the present invention. [Diagram 3] FIG. 2A is a cross-sectional view and FIG. 2B is a plan view of a multi-function ship in construction mode according to an embodiment. [Figure 4] 1A is a cross-sectional view, and FIG. 1B is a plan view of a multi-function ship in maintenance mode according to an embodiment. [Diagram 5] FIG. 1 is a schematic diagram of a floating offshore wind power generation facility. [Figure 6] FIG. 13 is a diagram illustrating a survey process using a multi-functional vessel in survey mode. [Figure 7] FIG. 13 is a diagram illustrating the transportation phase using a multi-purpose vessel in anchor handling mode. [Figure 8] FIG. 13 is a diagram illustrating a construction process using a multi-function ship in construction mode. [Figure 9] 11 is a diagram illustrating the process of switching the multi-function ship to a maintenance mode. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] Hereinafter, the multi-functional ship of this embodiment will be described with reference to the drawings. The multi-function vessel 10 is configured to be switchable among a survey mode M1 (FIG. 1), an anchor handling mode M2 ​​(FIG. 2), a construction mode M3 (FIG. 3), and a maintenance mode M4 (FIG. 4). The multi-function vessel 10 has a moonpool 16 that vertically passes through the hull 10a.

[0015] The multi-function vessel 10 can carry out various processes for constructing and maintaining a floating offshore wind power generation facility (hereinafter simply referred to as the power generation facility 1) as shown in Fig. 5. The power generation facility 1 generally comprises a floating structure 1a, a pillar 1b, a wind turbine 1c, etc. The pillar 1b is supported by the floating structure 1a. The wind turbine 1c is attached to the top of the pillar 1b. The floating structure 1a is moored to the seabed G by a number of anchors 1d and chains 1e.

[0016] As shown in FIG. 1, in the survey mode M1, a tower 12 is mounted on the deck 11. The tower 12 is disposed above the moonpool 16. In the survey mode M1, the multi-purpose vessel 10 performs a survey process. Specifically, as shown in FIG. 6, an observation survey pile 20 (also called a cone) is supported by the tower 12 and dropped into the water through the moonpool 16. The observation survey pile 20 is equipped with various sensors (load cell, water pressure gauge, etc.) for surveying the ground on the seabed G. By penetrating the observation survey pile 20 into the seabed G, data on the ground, such as tip resistance, surface friction, and water pressure, can be obtained.

[0017] As shown in Fig. 2, in anchor handling mode M2, multiple anchors 1d can be placed on the deck 11. A chain 1e to be used together with the anchor 1d is accommodated in a storage space 15 (shaded area in Fig. 2(a)) below the deck 11. The storage space 15 may include a moonpool 16. The storage space 15 may be the moonpool 16 itself. That is, the chain 1e may be accommodated only in the moonpool 16, or the chain 1e may be accommodated in the storage space 15 other than the moonpool 16. Furthermore, cargo other than the chain 1e may be accommodated in the storage space 15.

[0018] As shown in FIG. 7, in anchor handling mode M2, a bottom cover 17 is attached to the bottom of the moonpool 16. Therefore, even if a load such as a chain 1e is stored in the moonpool 16, the load can be prevented from falling into the water. In other words, the moonpool 16 can be used as a storage space 15 for storing the load. The bottom cover 17 may be watertight, but it is more preferable that it is not watertight. By making the bottom cover 17 non-watertight, the structure of the bottom of the moonpool 16 for attaching the bottom cover 17 can be simplified. In addition, since the chain 1e is used underwater, there is no problem if it gets wet during transportation.

[0019] The multi-purpose vessel 10 is equipped with a crane 10b for gripping and moving the anchor 1d, a winch 10c for stretching the chain 1e, and the like. In the anchor handling mode M2, the multi-purpose vessel 10 transports the anchor 1d and the chain 1e from a port or the like to the construction site of the power generation facility 1. Furthermore, the anchor 1d is placed underwater while stretching the chain 1e. At this time, since the yagura 12 and the like used in other modes are not on the deck 11, more anchors 1d can be placed on the deck 11. In addition, the chain 1e can be stored in the storage space 15 including the moon pool 16, and dead space can be reduced.

[0020] In this way, by being able to load more anchors 1d and chains 1e, the number of times the multi-function ship 10 travels back and forth between the port or the like and the construction site for transportation can be reduced. The size of the crane 10b and winch 10c for operating the anchors 1d and chains 1e is small. For this reason, the crane 10b and winch 10c may be mounted on the multi-function ship 10 not only in the anchor handling mode M2, but also in the survey mode M1, construction mode M3, and maintenance mode M4. The crane 10b and winch 10c can also be used in the survey process, construction process, and maintenance process.

[0021] As shown in FIG. 3, in construction mode M3, a construction crane 13 is mounted on the deck 11. The construction crane 13 grasps and moves a suction pile 19. The suction pile 19 is fixed to the seabed G. The suction pile 19 and the floating structure 1a are moored by a chain 1e. This makes it possible to prevent the power generation facility 1 from being carried away by ocean currents, etc. In order to moor the power generation facility 1 to the seabed G, the anchor 1d and the suction pile 19 may be used together, or only one of the anchor 1d and the suction pile 19 may be used. The suction pile 19 may also be referred to as a suction anchor.

[0022] The construction crane 13 may throw the suction pile 19 into the water from the side of the hull 10a. Alternatively, as shown in Fig. 8, the suction pile 19 may be thrown into the water through a moon pool 16. As shown in Fig. 3, the construction crane 13 is larger than the crane 10b for operating the anchor 1d, etc., and occupies a large area on the deck 11. For this reason, it is preferable to equip the multi-purpose ship 10 with the construction crane 13 when performing the construction process, and not to equip the construction crane 13 in other cases.

[0023] As shown in Fig. 4, in the maintenance mode M4, a gangway 14 is installed on the deck 11. The gangway 14 is equipped with a movable ladder. After the power generation facility 1 is constructed, the gangway 14 is used for workers to transfer from the hull 10a to the power generation facility 1 when performing work such as maintenance and inspection.

[0024] The tower 12, the construction crane 13, and the gangway 14 are detachable from the deck 11. In other words, by attaching and detaching the tower 12, the construction crane 13, and the gangway 14 to and from the deck 11, the modes M1 to M4 can be switched.

[0025] Next, a method for investigating, constructing, and maintaining the power generation facility 1 using the multi-purpose ship 10 will be described.

[0026] When constructing the power generation facility 1, an investigation process is carried out first. In the investigation process, a ground investigation of the seabed G at the planned construction site is carried out. At this time, the multi-purpose vessel 10 is in investigation mode M1, and the yagura 12 is installed on the deck 11. In the investigation process, the yagura 12 is used to penetrate the observation investigation piles 20 into the seabed G, and various data are acquired (see FIG. 6).

[0027] Next, the anchor handling process is performed. The anchor handling process is divided into a transportation phase and an installation phase. In both the transportation phase and the installation phase, the multi-function vessel 10 is in the anchor handling mode M2. To switch from the survey mode M1 to the anchor handling mode M2, the yagura 12 is removed from the deck 11 at a port or the like.

[0028] In the transportation phase, the anchor 1d and chain 1e for mooring the power generation facility 1 are transported to the planned construction site. At this time, for example, the chain 1e is accommodated in the accommodation space 15, and the anchor 1d is placed on the deck 11. However, the chain 1e may be placed on the deck 11, or the anchor 1d may be accommodated in the accommodation space 15. Also, in the transportation phase, parts such as the floating structure 1a may be towed. In the installation phase, the anchor 1d is installed on the seabed G, and the chain 1e is extended.

[0029] Next, the construction process is carried out. At this time, the multi-purpose ship 10 is in the construction mode M3, and the construction crane 13 is installed on the deck 11. In order to switch from the anchor handling mode M2 ​​to the construction mode M3, the construction crane 13 is attached to the deck 11 at a port or the like. In the construction process, the power generation facility 1 is constructed at the planned construction site. That is, the floating structure 1a is assembled, the columns 1b and the wind turbines 1c are fixed to the floating structure 1a, the suction piles 19 are fixed to the seabed G, the floating structure 1a is moored to the anchors 1d or the suction piles 19, and the like can be performed. In these operations, the construction crane 13 can be used. When the construction of the power generation facility 1 is completed, wind power generation is started.

[0030] Next, the maintenance process is performed. At this time, the multi-purpose ship 10 is in the maintenance mode M4, and the gangway 14 is installed on the deck 11. To switch from the construction mode M3 to the maintenance mode M4, the construction crane 13 is removed from the deck 11 at a port or the like, and the gangway 14 is installed. FIG. 9 shows an example of how the gangway 14 is installed on the deck 11. In the example of FIG. 9, the gangway 14 is fixed to a top cover 18 for closing the moonpool 16. The maintenance mode M4 can be easily set by attaching the top cover 18 together with the gangway 14 to the top of the moonpool 16 at a port or the like. In this example, the gangway 14 is located above the moonpool 16. However, as shown in FIG. 4, the gangway 14 may be located at a position away from the moonpool 16.

[0031] As described above, the multi-purpose vessel 10 of this embodiment can be switched among a survey mode M1, an anchor handling mode M2, a construction mode M3, and a maintenance mode M4. In the survey mode M1, the yagura 12 is attached to the deck 11. In the anchor handling mode M2, the anchor 1d of the power generation facility 1 can be placed on the deck 11, and the chain 1e of the power generation facility 1 can be accommodated in the accommodation space 15 below the deck 11, and the anchor 1d can be installed on the seabed G and the chain 1e can be extended. In the construction mode M3, the construction crane 13 is attached to the deck 11. In the maintenance mode M4, the gangway 14 is attached to the deck 11.

[0032] According to this embodiment, one multi-function ship 10 can execute the survey, transportation, construction, and maintenance processes by switching between the survey mode M1, the anchor handling mode M2, the construction mode M3, and the maintenance mode M4. Therefore, when constructing and maintaining the power generation facility 1, costs can be reduced compared to the case where multiple dedicated ships are prepared for each process. In addition, if multiple dedicated ships are prepared, the dedicated ships will be in a dormant state during the period when the process that the dedicated ship is responsible for is not executed, and the operating rate will decrease. In response to such a problem, the multi-function ship 10 can execute multiple processes, so that the dormant state can be reduced and the operating rate can be improved. Furthermore, compared to the case where the yagura 12, the construction crane 13, the gangway 14, and the accommodation space 15 are simultaneously provided on one ship, the hull 10a can be made smaller and mobility can be ensured.

[0033] In the survey mode M1, a tower 12 is provided above a moonpool 16 that vertically penetrates the hull 10a. By using such a tower 12, an observation survey pile 20 can be inserted into the seabed G to carry out the survey process.

[0034] In addition, in anchor handling mode M2, a non-watertight bottom cover 17 may be attached to the bottom of the moonpool 16 that vertically penetrates the hull 10a. This allows the moonpool 16 to be used as a space for storing the chain 1e. Also, compared to when the bottom cover 17 is watertight, the structure of the attachment portion of the bottom cover 17 can be simplified.

[0035] Also, in the maintenance mode M4, a top cover 18 to which the gangway 14 is fixed may be arranged so as to cover the upper part of the moonpool 16 that vertically penetrates the hull. With this configuration, the top cover 18 can be used as a part for attaching the gangway 14 to the hull 10a. In other words, when switching the multi-function vessel 10 between the maintenance mode M4 and the other modes M1 to M3, it is only necessary to replace the top cover 18. This makes it easier to switch between modes.

[0036] The technical scope of the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the present invention.

[0037] For example, in the above embodiment, the modes are switched in the order of survey mode M1, anchor handling mode M2, construction mode M3, and maintenance mode M4. However, this switching order can be changed. For example, in order to construct and maintain multiple power generation facilities 1 in parallel, each mode of the multifunctional ship 10 may be flexibly switched. Also, the construction mode M3 does not necessarily have to be included, and may be configured to be appropriately implemented as necessary.

[0038] In addition, within the scope of the spirit of the present invention, it is possible to replace the components in the above-described embodiments with well-known components as appropriate, and the above-described embodiments and variations may be combined as appropriate. [Explanation of symbols]

[0039] 1d...Anchor 1e...Chain 10...Multi-function vessel 10a...Hull 10b...Crane 11...Deck 12...Scaffolding 13...Construction crane 14...Gangway 15...Storage space 16...Moon pool 17...Bottom cover 18...Top cover G...Seabed

Claims

1. A survey mode with a yagura installed on the deck, an anchor handling mode in which an anchor of the offshore wind power generation facility can be placed on the deck, a chain of the offshore wind power generation facility can be accommodated in an accommodation space below the deck, and the anchor can be installed on the seabed and the chain can be stretched; a maintenance mode in which a gangway is attached to the deck, and a maintenance mode in which a gangway is attached to the deck can be switched by attaching and detaching the yagura and the gangway to correspond to each mode, A multi-function ship, in which the yacht cannot be attached to the deck in the anchor handling mode and the maintenance mode.

2. 2. A multi-function vessel as described in claim 1, wherein in the survey mode, the yagura is provided above a moonpool that vertically penetrates the vessel body.

3. 3. A multi-purpose vessel according to claim 1 or 2, wherein in the anchor handling mode, a non-watertight bottom cover is attached to the bottom of a moonpool that vertically penetrates the vessel hull.

4. 3. The multi-functional vessel according to claim 1 or 2, wherein in the maintenance mode, an upper cover to which the gangway is fixed is positioned so as to cover an upper portion of a moonpool that vertically penetrates the vessel body.

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