JP2015133767A - Laying method of subaqueous cable and laying structure of subaqueous cable - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a laying method of subaqueous cable and a laying structure of subaqueous cable capable of swiftly laying a subaqueous cable.SOLUTION: The laying method of subaqueous cable includes: defining k in plural on-water facilities as an integer larger than 1, a first laying step in which a cable is laid from k=1 to a predetermined number in order, while adding an excess length in the front part and the tail part of the cable in a cable lay direction on the water bottom between the 2k-1-th on-water facility and the 2k-th on-water facility by interposing a pitch where no cable is laid between a second k-th on-water facility and a second k+1-th on-water facility; a second lay step in which the cable is laid while adding an extra length to the cable at the front and the trail of the cable in the cable laying direction on the water bottom between a 2k-th on-water facility and a 2k+1-th on-water facility, where is spaced in the first laying step, from k=1 to a predetermined number in order, or from k to 1 in order.

Description

  The present invention relates to a submarine cable laying method and a submarine cable laying structure.

  In recent years, offshore wind power generation has been actively promoted because it can generate power more stably and efficiently than onshore wind power generation.

  In order to transmit power from a offshore facility such as a wind power generation facility in offshore wind power generation, a bottom (submarine) cable is used. The submarine cable is laid by a cable laying ship that feeds the cable from the surface of the water toward the bottom of the water.

  In addition, as a laying method of a submarine cable, it describes in patent document 1, for example.

JP-A-4-138008

  At this time, since the cable is laid by the laying ship from the surface of the water toward the bottom of the water, the cable is easily affected by the weather at the time of laying due to wind blown on the laying ship or a tidal current in water. Therefore, it is desirable to lay the bottom cable quickly while the weather is stable.

  The present invention is to provide a submarine cable laying method and a submarine cable laying structure capable of laying a submarine cable quickly.

According to a first aspect of the invention,
When k is an integer greater than or equal to 1 among multiple water facilities, extra cable length is added before and after the cable laying direction at the bottom of the water between the 2k-1 and 2k water facilities However, the cable is laid, and k is sequentially increased from 1 to a predetermined number without laying the cable between the 2kth water facility and the 2k + 1th water facility. Laying process;
Laying the cable while adding an extra cable length in the cable laying direction to the bottom of the water between the 2k-th water facility and the 2k + 1-th water facility spaced apart in the first laying step. A second laying step in which k is sequentially performed from 1 to a predetermined number, or k is sequentially performed from a predetermined number to 1.
A method for laying a submarine cable is provided.

According to a second aspect of the invention,
In the first laying step,
Laying the cable at a position shifted from the 2k-1th water facility and the 2kth water facility in a direction perpendicular to the cable laying direction as viewed from the vertical direction;
In the second laying step,
A method of laying a submarine cable is provided in which the cable is laid out at a position shifted to the opposite side of the cable laid in the first laying step of the 2kth water facility and the 2k + 1th water facility.

According to a third aspect of the invention,
The surplus length in the first laying step and the second laying step is the height from the bottom of the water to the portion where the cable is connected to the water facility, and the cable from the water facility when viewed from the vertical direction. The submarine cable laying method according to the second aspect, which is equal to or more than the sum of the distance to the portion extending in the cable laying direction, is provided.

According to a fourth aspect of the invention,
A first laying cable is formed by connecting the end of the 2k-1th floating facility in the cable laying direction to the end of the second kth floating facility in the cable laying direction. And connecting the second laying cable from the end of the second kth floating facility in the cable laying direction to the end of the second k + 1 floating facility in the cable laying direction. There is provided a method for laying a submarine cable according to any one of the first to third aspects including a start-up step to be formed.

According to a fifth aspect of the present invention,
Among the plurality of water facilities, when k is an integer greater than or equal to 1, the 2k-1st water surface between the 2k-1th water facility and the 2kth water facility as viewed from the vertical direction. A first laying cable laid at a position shifted in a direction perpendicular to the cable laying direction from the water facility and the 2k-th water facility;
Laid on the bottom between the 2kth water facility and the 2k + 1th water facility, and shifted to the opposite side of the first laying cable of the 2kth water facility and the 2k + 1 water facility A second laying cable laid at a position;
A submarine cable laying structure is provided.

According to a sixth aspect of the present invention,
The first laying cable is connected from an end on the second number side in the cable laying direction of the 2k-1th floating facility to an end on the old number side in the cable laying direction of the 2kth floating facility. ,
The second laying cable is connected from an end on the second number side in the cable laying direction of the 2kth floating facility to an end on the old number side in the cable laying direction of the 2k + 1th floating facility. A submarine cable laying structure according to the fifth aspect is provided.

  ADVANTAGE OF THE INVENTION According to this invention, the submarine cable installation method and the submarine cable installation structure which can lay out a submarine cable rapidly are provided.

(A) is a top view which shows the laying structure of the bottom cable which concerns on one Embodiment of this invention, (b) is a side view which shows the laying structure of the bottom cable which concerns on one Embodiment of this invention. It is a figure which shows the flow of the laying process of the bottom cable which concerns on one Embodiment of this invention. It is a top view which shows a marking process. (A) is a top view which shows a 1st laying process and a 2nd laying process, (b) is a side view of (a). (A) is a top view which shows the laying state of the cable in a 1st laying process and a 2nd laying process, (b) is a side view of (a). It is a side view which shows a starting process. It is a top view which shows the 1st laying process and 2nd laying process in a modification.

<One Embodiment of the Present Invention>
Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

(1) Submarine cable laying structure First, a submarine cable laying structure according to an embodiment of the present invention will be described with reference to FIG. Fig.1 (a) is a top view which shows the laying structure of the bottom cable which concerns on one Embodiment of this invention, FIG.1 (b) is the side surface which shows the laying structure of the bottom cable which concerns on one Embodiment of this invention. FIG.

  The submarine cable laying structure according to the present embodiment has a (2k-1) th floating facility and a (2k) floating facility when k is an integer of 1 or more among a plurality of floating facilities (wind power generation facility 200). A first laying cable 100a installed at a position shifted from the 2k-1th floating facility and the 2kth floating facility in a direction perpendicular to the cable laying direction as viewed from the vertical direction, Laid on the bottom of the water between the 2kth water facility and the 2k + 1th water facility, and laid out at a position shifted to the opposite side of the first laying cable 100a of the 2kth water facility and the 2k + 1 water facility. A second laying cable 100b. Details will be described below.

  “Cable 100” such as “first laying cable 100a” and “second laying cable 100b” laid on the water floor in the present embodiment refers to a power cable, an optical fiber composite power cable, and the like. The cable 100 includes, for example, a three-core cable including a conductive core wire, an internal semiconductive layer, an insulating layer, and an external semiconductive layer from the center, an iron wire armor layer formed by combining a plurality of iron wires and the like, covering the three core cable, And an exterior provided on the outside of the armor layer.

  As shown in FIG. 1A, for example, a plurality of water facilities are arranged in a straight line. The “water facility” here is, for example, a wind power generation facility (offshore windmill) 200. In addition, any one or more of the plurality of water facilities may be a transformation facility or the like. In the following description, it is assumed that all the floating facilities for laying the cable 100 are the wind power generation facilities 200.

  As shown in FIG. 1B, the wind power generation facility 200 includes, for example, a blade (propeller) 210, a shaft portion that supports the blade 210, and a rotational force obtained from the blade 210 via the shaft portion. A power generation unit that generates electric power, a nacelle 220 that stores the shaft and the power generation unit, a support unit (tower unit) 230 that supports the nacelle 220 at a predetermined height, and a base unit 240 that supports the support unit 230 from the bottom of the water. Have.

  A cable protection tube 260 called a J tube is provided outside the wind power generation facility 200. The cable protection tube 260 is configured to prevent the cable 100 from being damaged by contact with the wind power generation facility 200 due to tidal currents, and to protect the cable 100 from drifting objects. The cable 100 is connected to the wind power generation facility 200 through the cable protection tube 260.

  The cable 100 is connected to each of the adjacent wind power generation facilities 200 along the arrangement direction in which the plurality of wind power generation facilities 200 are arranged. Hereinafter, the “cable laying direction” refers to a direction in which the cable 100 is laid along the arrangement direction in which the plurality of wind power generation facilities 200 are arranged.

  Here, the numbers in parentheses in FIG. 1A indicate the serial numbers of the wind power generation facilities 200. FIG. 1A shows, for example, first to fifth wind power generation facilities 200, and a plurality of wind power generation facilities 200 are provided beyond the fifth wind power generation facility 200. It is done.

  As shown in FIG. 1A, in the present embodiment, the plurality of cables 100 are arranged in a staggered manner with respect to the plurality of wind power generation facilities 200. Of the plurality of cables 100 arranged in a staggered manner, one cable 100 is a first laid cable 100a and the other cable 100 is a second laid cable 100b.

  The first laying cable 100a is laid on the bottom of the water between the (2k-1) th and the 2kth wind power generation facilities 200, where k is an integer equal to or greater than one. Specifically, the first laying cable 100a is laid on the bottom of the water between the first, second, third, and fourth wind power generation facilities 200. Note that the first laying cable 100a is also laid on the bottom of the water between the two corresponding wind power generation facilities 200, which are not shown in the drawings.

  In addition, the cable protection tube 260 is provided, for example, at the end of the wind power generation facility 200 on the young number side in the cable laying direction and the end of the old number side in the cable laying direction. The first laying cable 100a extends from the end on the second number side in the cable laying direction of the 2k-1 wind power generation facility 200 to the end on the old number side in the cable laying direction of the 2kth wind power generation facility 200. Connected. In the first wind power generation facility 200, the end portion on the young number side in the cable laying direction is the end portion on the opposite side to the old number side in the cable laying direction.

  In addition, the first laying cable 100a is laid at a position shifted from the 2k-1st and 2kth wind power generation facilities 200 in a direction perpendicular to the cable laying direction when viewed from the vertical direction.

  On the other hand, the second laying cable 100b is laid on the bottom of the water between the 2k-th and 2k + 1-th wind power generation facilities 200, specifically, the second and third, fourth and fifth. Are installed on the bottom of the water between the wind power generation facilities 200 of the plant. Note that the second laying cable 100b is also laid on the bottom of the water between the two corresponding wind power generation facilities 200 in the sixth and later, not shown.

  The second laying cable 100b is arranged in a staggered manner with respect to the first laying cable 100a when viewed from the vertical direction. Specifically, the second laying cable 100b is connected to an end on the old number side in the cable laying direction of the 2k + 1 wind power generation facility 200 from an end on the second number side in the cable laying direction of the 2kth wind power generation facility 200. Connected to the part. The second laying cable 100b is laid at a position shifted to the opposite side to the first laying cable 100a of the 2kth and 2k + 1th wind power generation facilities 200. Thus, the first laying cable 100a and the second laying cable 100b are laid so as not to cross each other.

(Specific dimensions)
The distance between adjacent wind power generation facilities 200 is, for example, not less than 100 m and not more than 10 km. Moreover, when viewed from the vertical direction, the distance from the wind power generation facility 200 to the portion where the cable 100 extends in the cable laying direction is, for example, 5 m or more and 3000 m or less. The voltage applied to the cable 100 is, for example, 6 kV or more and 400 kV or less. The diameter of the cable 100 is 30 mm or more and 300 mm or less.

(2) Submarine cable laying method Next, the submarine cable laying method according to the present embodiment will be described with reference to FIGS. FIG. 2 is a diagram showing a flow of a submarine cable laying process according to the present embodiment. FIG. 3 is a plan view showing a marking process. Fig.4 (a) is a top view which shows a 1st laying process and a 2nd laying process, FIG.4 (b) is a side view of (a). Fig.5 (a) is a top view which shows the laying state of the cable in a 1st laying process and a 2nd laying process, FIG.5 (b) is a side view of (a). FIG. 6 is a side view showing the start-up process.

  The submarine cable laying method of the present embodiment is the 2k-1st floating facility and the 2kth floating facility, where k is an integer greater than or equal to 1 among a plurality of floating facilities (wind power generation facility 200). The cable 100 is laid while adding an extra length of the cable 100 in the cable laying direction before and after the cable laying space between the second water facility and the second k + 1 water facility without the cable 100 being laid. Laying a cable on the bottom between the first laying step in which k is sequentially increased from 1 to a predetermined number and the 2kth water facility and the 2k + 1th water facility that are spaced in the first laying step Laying the cable 100 while adding the extra length of the cable 100 before and after the direction, and a second laying step of sequentially performing k from 1 to a predetermined number. Details will be described below.

  In addition, only the foundation part 240 is previously provided in the wind power generation facility 200 before the process of laying the following cables 100.

(Marking step S110)
First, as shown in FIG. 3, a work boat (not shown) adds an extra length (b + c or more), which will be described later, to the adjacent wind power generation facility 200 before and after the cable laying direction. The markings 300 are arranged at the start point and the end point where the cable 100 is laid (S110). 3 indicates the laying position of the cable 100. Here, “before and after the cable laying direction” means the younger number side and the old number side of the wind power generation facility 200 laying the cable 100. The marking 300 is a buoy or the like that floats on the water.

  In the marking step S110, the marking 300 is arranged at a position shifted from the 2k-1st and 2kth wind power generation facilities 200 in a direction perpendicular to the cable laying direction as viewed from the vertical direction, and the 2kth and 2nd. The marking 300 is arranged on the opposite side of the marking 300 arranged with respect to the 2k-1th and 2kth wind power generation facilities 200 of the 2k + 1th wind power generation facility 200.

(First laying step S120)
Next, as shown in FIG. 4B, the cable 100 is laid (dropped) toward the bottom of the water while the cable 100 is fed out from the water by the laying ship 10. At this time, the cable 100 is laid using the above-described marking 300 as a mark. In addition, the cable 100 is laid in a state where a connecting portion such as a pooling eye (not shown) is provided at the end of the cable 100.

  As shown in FIG. 4 (a), while adding the extra length of the cable 100 before and after the cable laying direction to the bottom of the water between the 2k-1th and 2kth wind power generation facilities 200, the cable 100 is laid. At this time, the cable 100 is laid in a straight line along the arrangement direction of the wind power generation facility 200 including the extra length.

  Further, as shown in FIG. 4A, the cables are shifted from the 2k-1th and 2kth wind power generation facilities 200 in a direction perpendicular to the cable laying direction when viewed from the vertical direction. 100 is laid. In this way, the cable 100 to be the first laying cable 100a is laid on the bottom of the water.

  Here, the extra length of the cable 100 will be described with reference to FIGS. 5 (a) and 5 (b).

  As shown in FIGS. 5A and 5B, the distance between adjacent wind power generation facilities 200 is a, and the cable 100 is connected to the wind power generation facility 200 via the cable protection tube 260 from the bottom of the water. The height from the connected water surface to b is b, and the distance from the wind power generation facility 200 to the portion where the cable 100 extends in the cable laying direction when viewed from the vertical direction, that is, the cable 100 from the wind power generation facility 200. Let c be the distance shifted in the direction perpendicular to the cable laying direction.

  In the first laying step S120, the extra length of the cable 100 added to the distance a between the 2k-1th and 2kth wind power generation facilities 200 in the front and rear of the cable laying direction is equal to or greater than b + c. . That is, the total length of the cable 100 laid for the 2k−1th and 2kth wind power generation facilities 200 is a + 2b + 2c or more in total. In addition, it is preferable that a margin such as an error in the dropping position of the cable 100 or a movement error due to the power flow of the cable 100 is added to the extra length. In this way, the cable 100 is laid with the extra length added, so that the cable 100 sunk in the bottom of the water at a position shifted in a direction perpendicular to the cable laying direction with respect to the wind power generation facility 200 is replaced with the wind power generation facility. It is possible to connect to 200 predetermined connection portions.

  Next, the laying ship 10 is moved so as to leave an interval without laying the cable 100 between the second k-th and (2k + 1) -th wind power generation facilities 200.

  Thus, laying the cable 100 on the bottom of the water between the 2k−1 and 2kth wind power generation facilities 200, and spacing the 2kth and 2k + 1th wind power generation facilities 200, k is sequentially performed from 1 to a predetermined number.

  Specifically, for example, the cable 100 is laid between the first and second wind power generation facilities 200 (S120-1), and the third and fourth wind power generation facilities 200 are spaced apart from each other. The cable 100 is laid between them (S120-2), and the cable 100 is laid on the fifth and subsequent wind power generation facilities 200 at intervals (S120-3).

  When the number of wind power generation facilities 200 is an odd number, that is, 2N-1 (N ≧ 2), the cable 100 is connected between the 2N-3rd and 2N-2nd wind power generation facilities 200 (k = N-1). By laying, the first laying step S120 is completed.

  On the other hand, when the number of wind power generation facilities 200 is an even number, that is, 2N (N ≧ 2), the cable 100 is laid between the 2N-1th and 2Nth wind power generation facilities 200 (k = N). Thus, the first laying step S120 is completed (S120).

(Second laying step S130)
Next, as shown in FIG. 4 (a), the laying ship is returned to the 2k-th wind power generation facility 200, and the 2k-th and 2k + 1-th wind powers spaced in the first laying step S120 are provided. Between the power generation facilities 200, the cable 100 is laid on the bottom of the water while adding an extra cable length in the cable laying direction.

  Further, as shown in FIG. 4A, the cable 100 is laid out at a position shifted to the opposite side of the cable 100 laid in the first laying step S120 of the 2k-th and 2k + 1-th wind power generation facilities 200. To do. Thereby, it is suppressed that the cable 100 laid with the extra length added in the first laying step S120 and the cable 100 laid with the extra length added in the second laying step S130 intersect. In this way, the cable 100 to be the second laying cable 100b is laid on the bottom of the water.

  In the second laying step S130, as in the first laying step S120, an extra length of the cable 100 of b + c or more is added before and after the 2k-th and 2k + 1-th wind power generation facilities 200 in the cable-laying direction. Is done.

  In this manner, the cable 100 is laid between the 2kth and 2k + 1th wind power generation facilities 200 in order from k to a predetermined number.

  Specifically, for example, the cable 100 is laid between the second and third wind power generation facilities 200 (S130-1), and the fourth and fifth wind power generation facilities 200 are spaced apart from each other. The cable 100 is laid between them (S130-2), and the cable 100 is laid on the sixth and subsequent wind power generation facilities 200 at intervals.

  When the number of wind power generation facilities 200 is an odd number, that is, 2N−1 (N ≧ 2), the cable 100 is laid between the 2N−2nd and 2N−1th wind power generation facilities 200 (k = N). This completes the second laying step S130.

  On the other hand, when the number of wind power generation facilities 200 is an even number, that is, 2N (N ≧ 2), the cable 100 is laid between the 2N-2nd and 2N-1th wind power generation facilities 200 (k = N). Thus, the second laying step S130 is completed (S130).

(Start-up process S140)
After the first laying step S120 and the second laying step S130, when the weather conditions are good, the start-up step S140 is performed as follows.

  As shown in FIG. 6, the winch 280 is installed on the base portion 240 of the wind power generation facility 200. A wire (not shown) having a shackle (not shown) attached to the tip is lowered from the winch 280 through the cable protection tube 260 toward the bottom of the water.

  Next, the work boat 20 is anchored near the wind power generation facility 200, and the diver 30 dives. The diver 30 connects the shackle to a pooling eye provided at the tip of the cable 100 in water. Next, by pulling the wire with the winch 280, the tip of the cable 100 is pulled up on the foundation 240 of the wind power generation facility 200 through the cable protection tube 260. Next, the cable 100 is connected to a predetermined connection portion of the wind power generation facility 200.

  At this time, the cable 100 is bent so as to return from the cable laying direction and is connected to the base portion 240. Thereby, it can relieve | moderate that the tension | tensile_strength applied to the cable 100 between the adjacent wind power generation facilities 200 is applied to the connection part of the cable 100 and the wind power generation facility 200 directly.

  The above process is performed for all the wind power generation facilities 200, and all the wind power generation facilities 200 are connected via the cable 100.

  Accordingly, as shown in FIG. 1, the cable 100 is connected to the cable of the second k-th wind power generation facility 200 from the end of the second k−1th wind power generation facility 200 in the cable laying direction. The first laying cable 100a is formed by connecting to the end portion on the old number side in the laying direction. In addition, by connecting the cable 100 from the end of the second k-th wind power generation facility 200 in the cable laying direction to the end of the second k + 1-th wind power generation facility 200 in the cable laying direction Then, the second laying cable 100b is formed (S140).

  Thus, the submarine cable laying process is completed.

  Thereafter, the support portion 230 is erected on the base portion 240 in a state where the blade 210 supports the nacelle 220 attached via the shaft portion. Thereby, the installation of the wind power generation facility 200 is completed.

(3) Effects according to the present embodiment According to the present embodiment and its modifications, the following one or more effects are achieved.

(A) According to the present embodiment, in the first laying step S120, the extra length of the cable 100 is added to the bottom of the water between the 2k-1 and the 2kth wind power generation facilities 200 before and after the cable laying direction. Then, the cable 100 is laid, and the k is sequentially set from 1 to a predetermined number without laying the cable 100 between the 2kth floating facility and the 2k + 1th wind power generation facility 200. In the second laying step S130, an extra length of the cable 100 is added before and after the cable laying direction to the bottom of the water between the 2k-th and 2k + 1-th wind power generation facilities 200 spaced in the first laying step S120. The cable 100 is laid out sequentially from k to a predetermined number. Thereby, the cable 100 can be laid quickly on the bottom of the water.

  Here, as a comparative example, a case will be considered in which cables 100 are sequentially laid out one by one with respect to a plurality of wind power generation facilities 200 in a staggered manner as viewed from the vertical direction.

  In the comparative example, when m is an integer greater than or equal to 1, first, the cable is laid while adding the extra length of the cable before and after the cable laying direction to the bottom of the water between the mth and m + 1th wind power generation facilities. . The extra length of the cable is provided in order to connect to a predetermined connection part of the wind power generation facility from the bottom of the water. Next, a cable is connected to each of the mth and m + 1th wind power generation facilities. Next, the laying ship is turned back by the distance of the extra length before and after the (m + 1) th wind power generation facility. Next, the cable is installed while adding the extra length of the cable 100 to the bottom of the water between the (m + 1) th and (m + 2) th wind power generation facilities in the cable installation direction. Next, a cable is connected to each of the (m + 1) th and m + 2nd wind power generation facilities. The above processes are sequentially laid and connected without any gap between the wind power generation facilities.

  In the comparative example, since it is necessary to turn the laying ship back by the distance of the extra length before and after each wind power generation facility, a large amount of time is required for the entire cable laying process. For this reason, it may be difficult to lay a plurality of cables in a day for a plurality of wind power generation facilities.

  On the other hand, according to this embodiment, since the cable 100 is laid in only one direction including the extra length, it is not necessary to turn back the laying ship and the cable 100 can be laid in a short time. it can. In addition, a plurality of cables 100 can be easily laid out for a plurality of wind power generation facilities in one day, and a laying ship can be returned at an early stage. As described above, according to the present embodiment, the cable 100 can be laid immediately on the bottom of the water.

(B) According to the present embodiment, the cables 100 are laid in a staggered manner with respect to the plurality of wind power generation facilities 200 as viewed from the vertical direction. Specifically, in the first laying step S120, the cable 100 is laid at a position shifted from the 2k-1st and 2kth wind power generation facilities 200 in a direction perpendicular to the cable laying direction as viewed from the vertical direction. To do. In the second laying step S130, the cable 100 is laid at a position shifted to the opposite side of the cable 100 laid in the first laying step S120 of the 2kth and 2k + 1th wind power generation facilities 200. Thereby, it is possible to prevent the cable 100 laid with the extra length added in the first laying step S120 from intersecting the cable 100 laid with the extra length added in the second laying step S130. .

(C) According to this embodiment, in the first laying step S120 and the second laying step S130, the extra length of the cable 100 added before and after the wind power generation facility 200 in the cable laying direction is such that the cable 100 is cabled from the bottom of the water. The height b to the portion above the water connected to the wind power generation facility 200 via the protective tube 260 and the distance from the wind power generation facility 200 to the portion where the cable 100 extends in the cable laying direction when viewed from the vertical direction. It is more than the sum (b + c) of c. As a result, the cable 100 submerged in the water bottom at a position shifted in a direction perpendicular to the cable laying direction with respect to the wind power generation facility 200 can be connected to a predetermined connection portion of the wind power generation facility 200.

<Modification of this embodiment>
Next, a modification of this embodiment will be described with reference to FIG. FIG. 7 is a plan view showing a first laying step and a second laying step in the modification.

  In the above-described embodiment, in the second laying step, k is set to lay the cable 100 on the bottom of the water between the 2k-th and (2k + 1) -th wind power generation facilities 200 that are spaced in the first laying step. However, the second laying step may be performed in the direction opposite to the cable laying direction in the first laying step. That is, in the second laying step, the cable is added while adding the extra length of the cable before and after the cable laying direction to the water bottom between the 2kth and 2k + 1th wind power generation facilities spaced in the first laying step. The laying may be sequentially performed from k to a predetermined number to 1.

  Hereinafter, in this modification, only elements different from the above-described embodiment will be described, and description of elements that are substantially the same as the elements described in this embodiment will be omitted.

  As shown in FIG. 7, in the first laying step S120, the cable 100 is laid on the bottom of the water between the 2k-1th and 2kth wind power generation facilities 200, and the 2kth and 2k + 1th The interval between the wind power generation facilities 200 is sequentially increased from 1 to a predetermined number.

  When the number of wind power generation facilities 200 is an odd number, that is, 2N-1 (N ≧ 2), the second N-3th and 2N-2nd wind power generation facilities 200 (k = N-1) in the first laying step S120. ), The second laying step S230 is performed in the direction opposite to the cable laying direction in the first laying step S120. In the second laying step S230, the cable 100 is laid between the second (N-1) -th and the second (N-2) -th wind power generation facilities 200 (k = N) (S230-1: not shown), and spaced apart. Cables are laid in order for the 2N-3rd and subsequent wind power generation facilities 200.

  Thereafter, as shown in FIG. 7, the cable 100 is laid between the fifth and fourth wind power generation facilities 200 (S230-N-1), and the third and second are spaced apart. By laying the cable 100 between the second wind power generation facilities 200 (S230-N), the second laying step S230 is completed.

  On the other hand, when the number of wind power generation facilities 200 is an even number, that is, 2N (N ≧ 2), in the first laying step S120, between the 2N-1th and 2Nth wind power generation facilities 200 (k = N). After laying the cable 100, the second laying step S230 is performed in the direction opposite to the cable laying direction in the first laying step S120. In the second laying step S230, the cable 100 is laid between the second (N-1) -th and the second (N-2) -th wind power generation facilities 200 (k = N) (S230-1: not shown), and spaced apart. Cables are laid in order for the 2N-3rd and subsequent wind power generation facilities 200.

  Thereafter, even when the number of wind power generation facilities 200 is an even number, the second laying step S230 is completed by laying the cable 100 between the third and second wind power generation facilities 200 (S230-N). .

  As described above, according to the modification, the second laying step S230 is performed in the direction opposite to the cable laying direction in the first laying step S120, so that the second laying step is performed after the first laying step. The distance that the laying ship returns can be saved.

<Other Embodiments of the Present Invention>
As mentioned above, although embodiment of this invention was described concretely, this invention is not limited to the above-mentioned embodiment, It can change variously in the range which does not deviate from the summary.

  In the above-described embodiment, the case where the wind power generation facility 200 is fixed to the bottom of the water by the base portion 240 has been described, but the wind power generation facility may be a floating type.

  Further, in the above-described embodiment, the process of laying the cable 100 mainly on the water facility such as the wind power generation facility 200 has been described. However, the wind power generation located at the end between the second laying process and the startup process. A step of laying a cable between the facility and the onshore power transmission facility may be performed.

  In the above-described embodiment, the case where only the foundation 240 is provided in advance in the wind power generation facility 200 before the submarine cable laying process has been described. However, the wind power generation facility includes all windmills and the like. May be installed.

  In the above-described embodiment, the case where the cable 100 is bent so as to return from the cable laying direction and connected to the base portion 240 in the start-up step S140 has been described. You may connect to.

  Further, in the above-described embodiment, the cable 100 is connected to the old number in the cable laying direction of the 2k-th wind power generation facility 200 from the end of the second k-th wind power generation facility 200 in the cable laying direction. To the end of the second k-th wind power generation facility 200 in the cable laying direction and from the end of the second k + 1 wind power generation facility 200 to the old number side in the cable laying direction. Although the case has been described, the portion where the cable is connected to the wind power generation facility may be anywhere. You may connect a cable to the edge part of the direction perpendicular | vertical to the cable installation direction of a wind power generation facility.

DESCRIPTION OF SYMBOLS 10 Installation ship 20 Work ship 30 Diver 100 Cable 100a 1st installation cable 100b 2nd installation cable 200 Wind power generation facility 210 Blade 220 Nacelle 230 Support part (tower part)
240 Base 260 Cable protection tube 280 Winch 300 Marking

Claims (6)

When k is an integer greater than or equal to 1 among multiple water facilities, extra cable length is added before and after the cable laying direction at the bottom of the water between the 2k-1 and 2k water facilities However, the cable is laid, and k is sequentially increased from 1 to a predetermined number without laying the cable between the 2kth water facility and the 2k + 1th water facility. Laying process;
Laying the cable while adding an extra cable length in the cable laying direction to the bottom of the water between the 2k-th water facility and the 2k + 1-th water facility spaced apart in the first laying step. A second laying step in which k is sequentially performed from 1 to a predetermined number, or k is sequentially performed from a predetermined number to 1.
A method for laying a submarine cable, comprising: In the first laying step,
Laying the cable at a position shifted from the 2k-1th water facility and the 2kth water facility in a direction perpendicular to the cable laying direction as viewed from the vertical direction;
In the second laying step,
2. The cable according to claim 1, wherein the cable is laid at a position shifted to the opposite side of the cable laid in the first laying step of the 2k-th water facility and the 2k + 1-th water facility. How to lay submarine cables. The surplus length in the first laying step and the second laying step is the height from the bottom of the water to the portion where the cable is connected to the water facility, and the cable from the water facility when viewed from the vertical direction. The method for laying a submarine cable according to claim 2, wherein the laying method is a sum of a distance to a portion extending in the cable laying direction. A first laying cable is formed by connecting the end of the 2k-1th floating facility in the cable laying direction to the end of the second kth floating facility in the cable laying direction. And connecting the second laying cable from the end of the second kth floating facility in the cable laying direction to the end of the second k + 1 floating facility in the cable laying direction. The method for laying a submarine cable according to any one of claims 1 to 3, further comprising a start-up step to be formed. Among the plurality of water facilities, when k is an integer greater than or equal to 1, the 2k-1st water surface between the 2k-1th water facility and the 2kth water facility as viewed from the vertical direction. A first laying cable laid at a position shifted in a direction perpendicular to the cable laying direction from the water facility and the 2k-th water facility;
Laid on the bottom between the 2kth water facility and the 2k + 1th water facility, and shifted to the opposite side of the first laying cable of the 2kth water facility and the 2k + 1 water facility A second laying cable laid at a position;
A submarine cable laying structure characterized by comprising: The first laying cable is connected from an end on the second number side in the cable laying direction of the 2k-1th floating facility to an end on the old number side in the cable laying direction of the 2kth floating facility. ,
The second laying cable is connected from an end on the second number side in the cable laying direction of the 2kth floating facility to an end on the old number side in the cable laying direction of the 2k + 1th floating facility. The laying structure for a submarine cable according to claim 5.

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