Shooter, underwater cable line, cable-laying ship, method for manufacturing underwater cable line, and method for laying underwater cable

Abstract

A shooter (1) comprises an endless track (2) that guides an underwater cable (210) between a cable-laying ship (100) and a water surface (510). The endless track (2) has an arc-shaped track extending from the cable-laying ship (100) to the water surface (510).

Description

Chute, subaqueous cable line, laying ship, method for manufacturing subaqueous cable line, and method for laying subaqueous cable

[0001] The present disclosure relates to a chute, a subaqueous cable line, a laying ship, a method for manufacturing a subaqueous cable line, and a method for laying a subaqueous cable. The present application claims priority based on Japanese Patent Application No. 2025-055791 filed on March 28, 2025. All the contents described in the above Japanese application are incorporated herein by reference.

[0002] Patent Document 1 discloses a laying ship. The laying ship is provided with a chute that guides a cable from the ship to the water surface. The chute is formed in an arc shape. The chute is provided at the stern such that the cable guided from the ship to the water surface draws an arcuate trajectory extending from the ship to the water surface. The cable is guided from the ship into the water by sliding down the chute.

[0003] Japanese Unexamined Patent Publication No. 2017-99171

[0004] The chute of the present disclosure includes an endless track that guides a subaqueous cable between a laying ship and a water surface. The endless track has an arcuate trajectory extending from the laying ship to the water surface.

[0005] Fig. 1 is a schematic side view showing the chute of the embodiment. Fig. 2 is a schematic enlarged view of area A in Fig. 1. Fig. 3 is a schematic plan view showing area A in Fig. 1 as viewed from above. Fig. 4 is a schematic enlarged view of area B in Fig. 1. Fig. 5 is a schematic plan view showing area B in Fig. 1 as viewed from above. Fig. 6 is a schematic top view showing a track plate constituting the endless track provided in the chute of the embodiment. Fig. 7 is a schematic side view showing a track plate constituting the endless track provided in the chute of the embodiment. Fig. 8 is a schematic enlarged view of area C in Fig. 4. Fig. 9 is a schematic enlarged view of area D in Fig. 4.

[0006] Generally, a chute is formed of an arcuate plate material. Therefore, friction between the sliding cable and the chute increases, resulting in an increase in the lateral pressure acting on the cable.

[0007] One object of the present disclosure is to provide a chute that easily reduces the lateral pressure acting on a subaqueous cable.

[0008] The chute of this disclosure is designed to easily reduce the lateral pressure acting on the underwater cable.

[0009] First, the embodiments of this disclosure will be listed and described.

[0010] (1) A chute according to one aspect of the present disclosure includes an endless track for guiding a submarine cable between a laying vessel and the water surface. The endless track has an arc-shaped track extending from the laying vessel to the water surface.

[0011] The chute described in (1) above makes it easier to reduce friction between the submarine cable and the chute, thus making it easier to reduce the lateral pressure acting on the submarine cable. In this specification, lateral pressure is the value obtained by dividing the tension acting on the submarine cable during installation by the radius of curvature of the submarine cable. The radius of curvature of the submarine cable corresponds to the arc-shaped trajectory of the endless track. The chute described in (1) above allows the submarine cable to be installed in the seabed at even greater depths when the radius of curvature of the endless track is constant. Furthermore, when the water depth is constant, the chute described in (1) above makes it easier to reduce the radius of curvature of the endless track, thus making it easier to lower the maximum height between the deck of the installation vessel and the endless track. Moreover, compared to a rotary sheave, the chute described in (1) above makes it easier to lower the maximum height between the deck of the installation vessel and the endless track than the maximum height between the deck of the installation vessel and the sheave.

[0012] (2) In the shooter described in (1) above, the continuous track may include an endless band formed by connecting a plurality of track plates to one another.

[0013] The chute described in (2) above can easily transport even relatively heavy underwater cables.

[0014] (3) In the shooter described in (2) above, the surface of each of the plurality of track plates located outside the endless band may have a radius of curvature corresponding to the radius of curvature of the track.

[0015] The shooter described in (3) above is more effective in preventing localized increases in lateral pressure acting on the underwater cable compared to the case where the surface of the outer side of the endless band on each track plate is flat.

[0016] (4) In the shoemaker described in (2) or (3) above, each of the plurality of shoe plates may have a connecting portion that connects adjacent shoe plates among the plurality of shoe plates. The connecting portion is provided on both sides of each of the plurality of shoe plates in a direction along the width.

[0017] Typically, the underwater cable rests in the center of the track plate. Therefore, by having the connecting points on both sides of the track plate rather than in the center, the load of the underwater cable is less likely to act on the connecting points. Consequently, it is easier to maintain the connection between adjacent track plates at the connecting points.

[0018] (5) In any of the shooters described in (2) to (4) above, the track may be equipped with a drive wheel that transmits power from a power source to the plurality of track plates to cause it to run along the endless band.

[0019] The shooter described in (5) above can be made to travel on a continuous track.

[0020] (6) In any of the boots described in (2) to (5) above, the material of each of the plurality of boot plates may be steel.

[0021] The chute described in (6) above can be used for a long period of time because the material of each track plate is steel, which makes it easier to support the load of the underwater cable.

[0022] (7) A submarine cable line in one embodiment of the present disclosure comprises a submarine cable having a portion laid on the seabed at a depth of 300 m or more. The air weight per meter of the submarine cable is 20 kg / m or more.

[0023] Even if the submersible cable described in (7) above is a relatively heavy submersible cable with an air weight of 20 kg / m or more, it may have a portion laid on the seabed at a depth of 300 m or more.

[0024] (8) A laying vessel according to one aspect of the present disclosure is equipped with any of the chutes described in (1) to (6) above.

[0025] The cable laying vessel described in (8) above can be equipped with any of the chutes described in (1) to (6) above to easily reduce the lateral pressure acting on the submarine cable.

[0026] (9) In the laying vessel described in (8) above, the maximum height from the deck of the laying vessel to the chute may be 12 m or less.

[0027] The laying vessel described in (9) above can easily have its maximum height reduced.

[0028] (10) A method for manufacturing a submarine cable line according to one embodiment of the present disclosure comprises the step of manufacturing a submarine cable line by laying a submarine cable on the seabed from a laying vessel. The laying vessel is the laying vessel described in (8) or (9) above.

[0029] The method for manufacturing submarine cable lines described in (10) above makes it easier to reduce the lateral pressure acting on the submarine cable, and therefore makes it easier to manufacture submarine cable lines that include a portion of the submarine cable laid in relatively deep water.

[0030] (11) A method for laying a submarine cable according to one embodiment of the present disclosure comprises the step of laying a submarine cable on the seabed from a laying vessel. The laying vessel is the laying vessel described in (8) or (9) above.

[0031] The method of laying submarine cables described in (11) above makes it easier to reduce the lateral pressure acting on the submarine cables, thus making it easier to lay submarine cables in relatively deep water.

[0032] The embodiments of this disclosure will be described below with reference to the drawings. The shapes, sizes, and positional relationships shown in each figure are for illustrative purposes only and do not necessarily represent the actual shapes, sizes, and positional relationships. The same reference numerals in the figures indicate the same parts.

[0033] In the embodiments, the term "water" in phrases such as "bottom of the water," "water surface," and "underwater" refers to "sea," "lake," or "river." That is, the bottom of the water is the seabed, lakebed, or riverbed; the water surface is the sea surface, lake surface, or river surface; and underwater is the sea, lake, or river.

[0034] [Embodiment] <Churter> The chute 1 of the embodiment will be described with reference to Figures 1 to 9. The chute 1 of the embodiment is provided on the laying vessel 100 as shown in Figure 1. When laying the submarine cable 210 from the laying vessel 100 to the seabed 500, the chute 1 of the embodiment guides the submarine cable 210 from the laying vessel 100 to the water surface 510. Also, when pulling the submarine cable 210 up from the water 520 to the laying vessel 100, the chute 1 of the embodiment guides the submarine cable 210 from the water surface 510 to the laying vessel 100. One of the features of the chute 1 of the embodiment is that it is equipped with a specific continuous track 2.

[0035] ≪Endless Track≫ The endless track 2 is provided on the laying vessel 100 so as to be able to move freely, guiding the submarine cable 210 between the laying vessel 100 and the water surface 510. Because the chute 1 is equipped with the endless track 2, friction between the submarine cable 210 and the chute 1 is easily reduced, thus easily reducing the lateral pressure acting on the submarine cable 210. Therefore, if the radius of curvature r1 of the endless track 2, which will be described later, is constant, the chute 1 can lay the submarine cable 210 in the seabed 500 where the water depth d is even deeper. Also, if the water depth d is constant, the radius of curvature r1 of the endless track 2 can be made smaller, making it easier to lower the maximum height h between the deck 120 of the laying vessel 100 and the endless track 2. The endless track 2 has an arc-shaped track extending from the laying vessel 100 to the water surface 510. In this example, the endless track 2 is provided on a frame 8 installed on the deck 120 near the stern 110. The continuous track 2 in this example has an arc-shaped track extending from above the deck 120 to the water surface 510. The continuous track 2 comprises an endless band 3, a drive wheel 4, a road wheel 5, and a idler wheel 6. The end of the endless band 3 with the drive wheel 4 is called the starting end, and the end with the road wheel 5 is called the return end.

[0036] [Endless Band] The endless band 3 repeatedly circulates by running a forward path 3a on the outside (centrifugal direction of the arc trajectory) of a plurality of rollers 80 (Figures 2 and 4) arranged in an arc-shaped trajectory from the starting end to the return end, and a return path 3b on the inside (centripetal direction of the arc trajectory) of the plurality of rollers 80 from the return end to the starting end. In this example, the endless band 3 is formed in a ring shape by connecting a plurality of track plates 30 to each other. This endless band 3 makes it easy to transport even relatively heavy underwater cables 210. Each track plate 30 is made of steel. Because each track plate 30 is made of steel, it is easy to support the load of the underwater cable 210, and therefore it can be used for a long period of time. Each track plate 30 in this example has a base portion 31, a connecting portion 32, a fitting portion 33, and a rib 34, as shown in Figures 6 and 7.

[0037] <Base> The base 31 is in direct contact with the guided submarine cable 210. The base 31 is a rectangular plate. The base 31 has a surface 31a located on the outside of the endless band 3 and a back surface 31b opposite to surface 31a, located on the inside of the endless band 3. Surface 31a is the surface that contacts the submarine cable 210. Surface 31a is located on the outside of the curve of the arc-shaped track in the forward path 3a, while it is located on the inside of the curve of the arc-shaped track in the return path 3b.

[0038] The base portion 31 has a first end portion 311, a central portion 310, and a second end portion 312 arranged in order along the width of the base portion 31. The width of the base portion 31 is in the direction perpendicular to the first direction D1, which is the left direction in Figure 6, and the second direction D2, which is the right direction in Figure 6, when the surface 31a of the base portion 31 is viewed from above, as shown in Figure 6. The first direction D1 is the direction from the laying vessel 100 toward the water surface 510. The second direction D2 is the opposite direction to the first direction D1, and is the direction from the water surface 510 toward the laying vessel 100. In this example, the base portion 31 is configured such that the first end portion 311 and the second end portion 312 and the central portion 310 are offset from each other. That is, the central portion 310 has a projection 310a that protrudes in the first direction D1 more than the first end portion 311 and the second end portion 312. The first end 311 and the second end 312 have protruding portions 311a and 312a that project in a second direction D2 from the central portion 310. A recess 310b is provided between the protruding portions 311a and 312a of the first end 311 and the second end 312. The protruding portion 310a of the central portion 310 of the base portion 31 of adjacent track plates 30 fits into the recess 310b.

[0039] The surface 31a of the base 31 may have a radius of curvature r2 that corresponds to the radius of curvature r1 of the track of the endless track 2. That is, the surface 31a of the base 31 has a curved surface. The radius of curvature r1 is the radius of curvature of the forward path 3a of the endless band 3. That is, the radius of curvature r1 is the radius of curvature of the portion of the endless track 2 on which the submarine cable 210 runs. If the radius of curvature r1 is not uniform and at least a part of it is different, the radius of curvature r2 corresponds to the smallest radius of curvature r1. Corresponding to the radius of curvature r1 here means that the radius of curvature r2 is the same as the radius of curvature r1, as well as the case where the radius of curvature r2 is 0.9 times or more and 1.1 times or less of the radius of curvature r1. Because the radius of curvature r2 corresponds to the radius of curvature r1, it is easier to prevent the lateral pressure acting locally on the submarine cable 210 from becoming larger compared to the case where the surface 31a of the base 31 is flat.

[0040] The direction in which adjacent base portions 31 are bent is reversed between the forward path 3a and the return path 3b. That is, in the forward path 3a, as shown in Figure 8, the endless band 3 is bent so that the back surface 31b of the base portion 31 is on the inside of the bend and the front surface 31a is on the outside of the bend. In the return path 3b, as shown in Figure 9, the endless band 3 is bent so that the front surface 31a of the base portion 31 is on the inside of the bend and the back surface 31b is on the outside of the bend. For the sake of explanation, Figures 8 and 9 show only the base portions 31. In order to prevent adjacent base portions 31 from interfering with each other regardless of the direction in which they are bent, a gap 36 is provided between adjacent base portions 31, as shown in Figure 8. The gap 36 in this example is V-shaped, but is not particularly limited.

[0041] <Connecting Section> The connecting section 32 shown in Figures 6 and 7 connects adjacent track plates 30. The connecting section 32 is provided on both sides in the direction along the width of each track plate 30, i.e., at the first end 311 and the second end 312. Normally, the underwater cable 210 rests on the central section 310. Therefore, by providing the connecting section 32 at the first end 311 and the second end 312 rather than the central section 310, the load of the underwater cable 210 is less likely to act on the connecting section 32. Thus, the connecting section 32 is less likely to be damaged or worn, and it is easier to maintain the state in which adjacent track plates 30 are connected by the connecting section 32. Furthermore, because the connecting portion 32 is provided at the first end 311 and the second end 312 rather than the central portion 310, when the submarine cable 210 is mounted on the central portion 310, if the central portion 310 bends inward due to the load of the submarine cable 210, this indentation can act as a guide for the submarine cable 210, making it easier to guide the submarine cable 210 along the central portion 310.

[0042] The connecting portion 32 in this example has two sets of two first projections 321 and two sets of one second projection 322. The two first projections 321 are provided on the back surface 31b of the first end portion 311 and the back surface 31b of the second end portion 312, respectively. The two first projections 321 protrude toward the first direction D1 so that they are exposed from the first end portion 311 and the second end portion 312 when the base portion 31 is viewed from above. The two first projections 321 are provided so as to sandwich the second rib 342, which will be described later. The two first projections 321 are provided with through holes 321a that communicate with each other, as shown in Figure 7. The one second projection 322 is provided on the back surface 31b of the first end portion 311 and the back surface 31b of the second end portion 312, respectively. One second projection 322 protrudes toward the second direction D2 so that it is exposed from both the first end 311 and the second end 312 when the base 31 is viewed from above. One second projection 322 is formed at the tip of the second rib 342, which will be described later. The second projection 322 is provided with a through hole 322a, as shown in Figure 7. One second projection 322 at each end 311 and 312 of adjacent track plates 30 is inserted between the two first projections 321 at each end 311 and 312. A bolt 38 is inserted through the through holes 321a of the two first projections 321 and the through hole 322a of the one second projection 322, and a nut 39 is fastened to the bolt 38. This fastening connects adjacent track plates 30.

[0043] <Matching portion> The matching portion 33 is the space into which the teeth 421 of the drive wheel 4, which will be described later, fit. The matching portion 33 is provided on the back surface 31b of the first end 311 and the second end 312, respectively. In this example, each matching portion 33 is configured between two cylindrical portions 331. The two cylindrical portions 331 extend in a direction along the width of the base 31 so as to connect the first rib 341 and the second rib 342, which will be described later. In Figure 7, the first rib 341 is omitted from the illustration for the sake of explanation.

[0044] <Rib> The rib 34 reinforces the base portion 31. The rib 34 is provided on the back surface 31b of the base portion 31. The rib 34 of the present example includes two first ribs 341, two second ribs 342, and a plurality of third ribs 343. Each first rib 341 is the rib 34 located at the outermost position in the widthwise direction. The first rib 341 is provided along the first direction D1. Each second rib 342 is the rib 34 located at the second position from the outer side in the widthwise direction. The second rib 342 is provided along the first direction D1. The plurality of third ribs 343 are the ribs 34 located between the two second ribs 342. The plurality of third ribs 343 include the ribs 34 provided along the first direction D1 and the ribs 34 provided along the widthwise direction. In the present example, as shown in FIG. 7, the third rib 343 provided along the first direction D1 in FIG. 6 has a longer protruding length from the back surface 31b than the first rib 341 (FIG. 6) and the second rib 342. Therefore, the load acting on the fitting portion 33 when the submarine cable 210 shown in FIG. 1 is placed on the central portion 310 shown in FIG. 6 is reduced.

[0045] <Drive Wheel> As shown in FIG. 1 to FIG. 3, the drive wheel 4 drives the endless belt 3 to travel by transmitting the power of the power source 7 to the plurality of track shoes 30. The drive wheel 4 is a driving wheel. The power source 7 of the present example is a power unit 70. As shown in FIG. 1, the power unit 70 is disposed on the frame 8 below the crawler track 2. As shown in FIG. 1, the drive wheel 4 is provided at a position close to the cable pass line 150. When laying the submarine cable 210, the cable pass line 150 conveys the submarine cable 210 pulled out from a turntable (not shown) that stores the submarine cable 210 in a wound state to the chute 1. The member for storing the submarine cable 210 is not limited to the turntable, and may be a cable coil (cable tank) or a cable drum. The submarine cable 210 may be arranged directly coiled on the deck 120.

[0046] The drive wheel 4 has a rotating shaft portion 41, two first sprockets 42, and one second sprocket 43. The rotating shaft portion 41 is rotatably fixed to the frame 8. This fixing secures the drive wheel 4 to the frame 8. The two first sprockets 42 are mounted on the rotating shaft portion 41, spaced apart from each other along the axis of the rotating shaft portion 41. The outer periphery of each first sprocket 42 has multiple teeth 421. Each tooth 421 fits into a fitting portion 33 at each end 311, 312 of each track plate 30. The second sprocket 43 is mounted at one end of the rotating shaft portion 41. As shown in Figure 3, the second sprocket 43 is positioned outside one of the first sprockets 42. The outer periphery of the second sprocket 43 has multiple teeth 431. Each tooth 431 meshes with the endless chain 72, as shown in Figure 2. The endless chain 72 is stretched between the second sprocket 43 and a sprocket 71 connected to the rotating shaft of the power unit 70. The outer circumference of the sprocket 71 has multiple teeth 711. Each tooth 711 meshes with the endless chain 72. Unlike this example, the rotating shaft 41 of the drive wheel 4 may be directly connected to the power unit 70. In this configuration, the power unit 70 has a motor, and the first sprocket 42 is provided on the rotating shaft 41, which is the rotating shaft of the motor. In this case, the second sprocket 43, sprocket 71, and endless chain 72 are unnecessary.

[0047] When the power unit 70 rotates the sprocket 71, the endless chain 72 moves. When the endless chain 72 moves, the second sprocket 43 rotates. When the second sprocket 43 rotates, the rotating shaft 41 rotates. When the rotating shaft 41 rotates, both first sprockets 42 rotate. When both first sprockets 42 rotate, the endless belt 3 moves. In Figure 2, when the power unit 70 rotates the sprocket 71 counterclockwise, the endless belt 3 moves to guide the submarine cable 210 from the laying vessel 100 toward the water surface 510, and when the rotation direction of the sprocket 71 is turned clockwise, the endless belt 3 moves to guide the submarine cable 210 from the water surface 510 toward the laying vessel 100.

[0048] [Roller] As shown in Figures 1, 4 and 5, the roller 5 folds back the endless belt 3. The roller 5 is a driven wheel. The roller 5 is arranged at a position close to the water surface 510. The roller 5 includes a rotating shaft portion 51, a body portion 52 surrounding the rotating shaft portion 51, and flange portions 53 fixed to each end of the body portion 52. In this example, the rotating shaft portion 51 is rotatably attached to the tips of two leg portions 93 of a support member 9 to be described later. The endless belt 3 is stretched around the body portion 52. The body portion 52 rotates together with the rotation of the rotating shaft portion 51. The body portion 52 has a cylindrical shape. Both flange portions 53 restrict the endless belt 3 from falling off the body portion 52 in the direction along the axis of the rotating shaft portion 51. Each flange portion 53 has an annular plate shape. The outer diameter of both flange portions 53 is larger than the outer diameter of the body portion 52.

[0049] [Support Member] The support member 9 shown in Figures 4 and 5 supports the roller 5. The support member 9 includes two base portions 91 fixed to the stern 110, a rotating shaft portion 92 rotatably provided on the two base portions 91, and two leg portions 93 extending from the rotating shaft portion 92. The two leg portions 93 are fixed to the rotating shaft portion 92 at an interval from each other. The rotating shaft portion 51 of the roller 5 is rotatably fixed to the tips of the two leg portions 93. A counterweight 97 is arranged on the upper surfaces of the two leg portions 93 so as to bridge the two leg portions 93. The counterweight 97 prevents the endless belt 3 from fluttering due to the rocking of the laying ship 100 caused by waves or the like.

[0050] [Idle Wheel] As shown in Figures 1 to 3, the idler wheel 6 applies tension to the endless belt 3. The idler wheel 6 is rotatably mounted on the frame 8 at a point close to the drive wheel 4 between the drive wheel 4 and the idler wheel 5. The idler wheel 6 has a rotating shaft portion 61, a body portion 62 surrounding the rotating shaft portion 61, and flange portions 63 fixed to each end of the body portion 62. The rotating shaft portion 61 is rotatably fixed to the frame 8. The body portion 62 presses the return path 3b of the endless belt 3 toward the forward path 3a. Specifically, the body portion 62 pushes the vicinity of the starting end of the return path 3b of the endless belt 3 upward from below. That is, the body portion 62 is in contact with the surface 31a of the base portion 31 in the return path 3b of the endless belt 3. The body portion 62 rotates together with the rotation of the rotating shaft portion 61. The body portion 62 is cylindrical in shape. The two flange portions 63 restrict the endless band 3 from falling out of the body portion 62 in the direction along the axis of the rotating shaft portion 61. Each flange portion 63 is an annular plate shape. The outer diameter of both flange portions 63 is larger than the outer diameter of the body portion 62.

[0051] [Other] In this example, the endless belt 3 is also supported by a plurality of rollers 80, as shown in Figures 1, 2, and 4. The plurality of rollers 80 are located inside the endless belt 3, between the drive wheel 4 and the idler wheel 5, at locations closer to the drive wheel 4 and at locations closer to the idler wheel 5. The plurality of rollers 80 are rotatably fixed to the frame 8. Note that the plurality of rollers 80 are not an essential component. Furthermore, although not shown in the figures, the endless belt 3 may be equipped with a safety cover to prevent workers' hands or other objects from getting caught in the endless belt 3.

[0052] <Submersible Cable Line> The submersible cable line 200 of this embodiment includes a submersible cable 210 laid on the seabed 500, as shown in Figure 1. The submersible cable 210 has a portion laid on the seabed 500 where the water depth d is 300 m or more. The air weight per meter of the submersible cable 210 is 20 kg / m or more. Even if the submersible cable 210 has a relatively heavy air weight, such as the above air weight of 20 kg / m or more, the submersible cable line 200 can have a portion laid on the seabed 500 where the water depth d is 300 m or more. The above air weight may be 50 kg / m or more or 80 kg / m or more. The above air weight is, for example, 120 kg / m or less. That is, the above air weight is 20 kg / m or more and 120 kg / m or less, 50 kg / m or more and 120 kg / m or less, or 80 kg / m or more and 120 kg / m or less. The underwater cable 210 is, for example, a dynamic cable, a DC cable for interconnection, or an AC cable for interconnection.

[0053] <Laying Vessel> The laying vessel 100 of the embodiment is equipped with the chute 1 of the embodiment described above, as shown in Figure 1. The maximum height h from the deck 120 to the chute 1 of the laying vessel 100 may be 12 m or less. By being equipped with the chute 1 of the embodiment, the laying vessel 100 can lay the submarine cable 210 having an air weight of 20 kg / m or more to the seabed 500 at a water depth d of 300 m or more, even if the maximum height h is 12 m or less. The maximum height h may be 10 m or less or 8 m or less. The maximum height h is, for example, 2 m or more. That is, the maximum height h is 2 m or more and 12 m or less, 2 m or more and 10 m or less, or 2 m or more and 8 m or less.

[0054] <Method for Manufacturing Submarine Cable Lines> The method for manufacturing submarine cable lines according to this embodiment includes a step of manufacturing a submarine cable line 200 by laying a submarine cable 210 from a laying ship 100 to the seabed 500. In this step, the unwound submarine cable 210 is guided from the laying ship 100 to the water surface 510 by the chute 1 described above. Then, in this step, the submarine cable 210 is positioned at a predetermined landing point on the seabed 500. Positioning the submarine cable 210 on the seabed 500 includes positioning on the seabed surface and burying below the seabed surface. The method for manufacturing submarine cable lines in this example makes it possible to manufacture a submarine cable line 200 that includes a portion of the submarine cable 210 laid on the seabed 500 at a water depth d of 300 m or more, even if the submarine cable 210 has a relatively heavy weight in air, such as a weight in air of 20 kg / m or more.

[0055] <Method for Laying Submarine Cables> The method for laying submarine cables according to this embodiment includes the step of laying a submarine cable 210 from a laying vessel 100 to the seabed 500. In this step, the unfurled submarine cable 210 is guided from the laying vessel 100 to the water surface 510 by the chute 1 described above. This step then positions the submarine cable 210 at a predetermined landing point on the seabed 500. The submarine cable laying method in this example allows even a relatively heavy submarine cable 210, such as one with an air weight of 20 kg / m or more, to be laid on the seabed 500 where the water depth d is 300 m or more.

[0056] [Example of calculation] As an example of calculation, the maximum water depth to which a cable can be laid was calculated for three types of cables: the chute 1 of the embodiment, a conventional arc-shaped plate chute as described in Patent Document 1, and a conventional rotating sheave as described in Japanese Patent Application Publication No. 3-124208, when the radius of curvature when laying the underwater cable is of a specific size.

[0057] The specifications of the submersible cable used for the calculation are as follows: Outer diameter: approx. 177 mm; Weight in air: approx. 63 kg / m; Weight underwater: approx. 40 kg / m; Allowable lateral pressure: 4 ton / m

[0058] In the embodiment, the maximum water depth at which a submarine cable could be laid was 522 m when the radius of curvature r1 was 10 m.

[0059] Conventional arc-shaped chutes, with a radius of curvature of 10m, had a maximum water depth at which submarine cables could be laid at 260m.

[0060] Conventional rotary sheaves with a radius of curvature of 5m could lay submarine cables at a maximum depth of 246m. While theoretically calculated, a hypothetical rotary sheave with a radius of curvature of 10m could lay submarine cables at a maximum depth of 522m. However, a rotary sheave with a radius of curvature of 10m would have a diameter of 20m, which is impractical given the structure of existing cable-laying vessels. The aforementioned rotary sheave with a radius of curvature of 5m is the largest rotary sheave currently available.

[0061] From the above results, it can be seen that the chute 1 of the embodiment can lay submarine cables in deeper waters compared to conventional arc-shaped chutes and conventional rotary sheaves. The chute 1 of the embodiment is not only easier to implement than a hypothetical rotary sheave, but can also be mounted on existing cable laying vessels. Furthermore, the chute 1 of the embodiment can reduce the maximum height of the cable laying vessel compared to a hypothetical rotary sheave.

[0062] It should be noted that the present invention is not limited to the configurations shown in the embodiments, but is intended to include all modifications within the meaning and scope of the claims as indicated by the claims. It should be understood that at least one configuration or feature described in each embodiment and example can be combined with other embodiments and examples, or modified in various ways.

[0063] 1 Shooter 2 Track 3 Endless belt, 3a Forward track, 3b Return track 30 Track plate, 31 Base, 31a Surface, 31b Back surface 310 Center section, 310a Projection, 310b Recess 311 First end, 311a Projection 312 Second end, 312a Projection 32 Connecting section 321 First projection, 321a Through hole 322 Second projection, 322a Through hole 33 Fitting section, 331 Cylindrical section 34 Rib, 341 First rib, 342 Second rib, 343 Third rib 36 Gap, 38 Bolt, 39 Nut 4 Drive wheel 41 Rotating shaft, 42 First sprocket, 421 Teeth 43 Second sprocket, 431 Teeth 5 Road wheel 51 Rotating shaft section, 52 Body section, 53 Flange section 6 Idle wheel 61 Rotating shaft section, 62 Body section, 63 Flange section 7 Power source 70 Power unit, 71 Sprocket, 711 Teeth section 72 Endless chain 8 Frame, 80 Roller 9 Support member 91 Base section, 92 Rotating shaft section, 93 Leg section, 97 Counterweight 100 Laying vessel, 110 Stern, 120 Deck 150 Cable pass line 200 Submarine cable line, 210 Submarine cable 500 Seabed, 510 Water surface, 520 Underwater d Water depth, h Maximum height, r1, r2 Radius of curvature

Claims

1. A chute equipped with an endless track for guiding a submarine cable between a laying vessel and the water surface, wherein the endless track has an arc-shaped trajectory extending from the laying vessel to the water surface.

2. The shooter according to claim 1, wherein the continuous track comprises an endless band formed by connecting a plurality of track plates to one another.

3. The shoemaker according to claim 2, wherein the surface of each of the plurality of shoe plates located outside the endless band has a radius of curvature corresponding to the radius of curvature of the track.

4. The shoe boot according to claim 2 or 3, wherein each of the plurality of shoe boots has a connecting portion that connects adjacent shoe boots among the plurality of shoe boots, and the connecting portion is provided on both sides in the direction along the width of each of the plurality of shoe boots.

5. The shooter according to any one of claims 2 to 4, wherein the continuous track is equipped with a drive wheel that transmits power from a power source to the plurality of track plates to cause it to run along the endless band.

6. The shoe boot according to any one of claims 2 to 5, wherein the material of each of the plurality of shoe plates is steel.

7. A submarine cable line comprising a portion of the submarine cable laid on the seabed at a depth of 300 m or more, wherein the air weight per meter of the submarine cable is 20 kg / m or more.

8. A laying vessel comprising a chute according to any one of claims 1 to 6.

9. The laying vessel according to claim 8, wherein the maximum height from the deck of the laying vessel to the chute is 12 m or less.

10. A method for manufacturing a submarine cable line, comprising the step of manufacturing a submarine cable line by laying a submarine cable on the seabed from a laying vessel, wherein the laying vessel is the laying vessel described in claim 8 or claim 9.

11. A method for laying a submarine cable, comprising the step of laying a submarine cable on the seabed from a laying vessel, wherein the laying vessel is the laying vessel described in claim 8 or claim 9.

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