JPH0643640B2 - How to protect underwater linear structures - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention protects underwater linear laying objects such as communication cables and ropes laid underwater from damage caused by galling of large fish such as sharks. The present invention relates to a method of protecting a linear laid structure.

[Conventional technology]

Generally, with the expansion of data communication networks, communication cables such as optical fiber cables are laid in the sea to connect multiple data communication stations across the ocean, and high-speed, high-density data communication is performed via these communication cables. Is being carried out.

Further, not only this type of communication cable, but also other cables used for various purposes and underwater linear laying objects such as ropes and pipes are laid in the sea.

[Problems to be solved by the invention]

However, there is a problem that large fishes, especially sharks, bite these linear constructions and the linear constructions are damaged, and in the case of communication cables, phenomena such as deterioration of communication function and communication failure occur. Even in the case of linear facilities other than communication cables, similar problems have occurred due to damage by large fish, and effective solutions are desired.

Therefore, the present invention has a technical object to protect linear facilities such as cables and ropes from being damaged by large fish such as sharks.

[Means for solving problems]

The present invention has been made with the above points in mind,
Surrounding the linear structure by arranging two conductive electrodes in parallel on an underwater linear structure such as a cable or rope laid in water and applying a voltage to the both conductive electrodes by a power source for generating an electric barrier. The method for protecting an underwater linear structure is characterized in that an electric barrier for protecting the linear structure is formed on.

[Action]

Therefore, according to the present invention, a voltage is applied to the two conductive electrodes arranged in parallel to the underwater linear structure by a power source for generating an electric barrier, and the linear structure is formed around the underwater linear structure. When an electric barrier with a predetermined electric field strength for protection of the laying material is formed and large fish such as sharks approach the underwater linear laying material,
The electric barrier prevents electrical access to large fishes underwater linear laying due to electrical stimulation, prevents the underwater linear laying from being damaged by galling of large fishes, etc. Various problems such as functional deterioration and communication failure are resolved.

〔Example〕

Next, the present invention will be described in detail with reference to the drawings showing the embodiments thereof.

Example 1 First, FIGS. 1 and 2 showing Example 1 will be described.

In these drawings, (1) is an optical fiber cable as an underwater linear installation, (2) is a plurality of fixing rings attached to the outer periphery of the cable (1) at regular intervals, (3), (4 ) Are upper and lower support arms integrally provided at the upper end and the lower end of each fixing ring (2), and (5) and (6) are each upper support arm (3) and each lower support arm (4). Cable-shaped first and second conductive electrodes supported by, respectively, arranged in parallel with the cable (1), and connected to both conductive electrodes (5) and (6) by an electric barrier generating power source (7), for example. An AC voltage is applied, and an electric barrier having a predetermined electric field strength is formed around the cable (1).

The broken line in Fig. 1 indicates the cable (1) and both conductive electrodes.
The equipotential lines on the cross section orthogonal to (5) and (6) are shown.

Therefore, electrical stimulation of the electric barrier formed around the cable (1) prevents large fish such as sharks from approaching the cable (1), and biting of the cable (1) by large fish can occur. And the cable (1) is protected.

Example 2 Next, FIGS. 3 and 4 showing Example 2 will be described.

In these drawings, (8) is a cable as an underwater linear installation laid on the seabed, and (9) and (10) are laid on both sides of the cable (8) in parallel with the cable (8). 3rd and 4th
A conductive electrode, for example, an AC voltage is applied to both conductive electrodes (9) and (10) by an electric barrier generating power source (11), and an electric barrier having a predetermined electric field strength is formed around the cable (8).

The broken line in Fig. 4 indicates the cable (8) and both conductive electrodes.
The equipotential lines on the cross section orthogonal to (9) and (10) are shown.

Therefore, as in the case of the first embodiment described above, the electric barrier prevents the large fish (F) from approaching the cable (8) and protects the cable (8).

Example 3 Further, FIGS. 5 to 8 showing Example 3 will be described.

In FIGS. 5 and 6, (12) is a pillar made of a plurality of insulating materials standing upright on the seabed at regular intervals, and (13) is each pillar.
Cable as an underwater linear laying structure that penetrates the lower end of (12) and is laid near the seabed and has a metal jacket (14) that is a conductive electrode, and (15) is the upper end of each strut (12). Is a conductive electrode that is arranged in parallel with the cable (13) by penetrating the part, and the jacket (14)
AC voltage is applied to the conductive electrode (15) by the electric barrier generation power source (16) to form an electric barrier with a predetermined electric field strength around the cable (13), and the electric barrier forms a large fish cable (13). ) Is blocked.

The broken line in FIG. 6 indicates the cable (13) and the conductive electrode (1
The equipotential lines on the cross section orthogonal to 5) are shown.

Also, if the distance between the jacket (14) and the conductive electrode (15) is L,
The relationship between the electric field strength and the distance and the relationship between the electric potential and the distance on the cross section orthogonal to the cable (13) and the conductive electrode (15) are as shown in FIGS. 7 and 8, respectively.

Example 4 Next, FIG. 9 showing Example 4 will be described.

In the figure, (17) is a cable as an underwater linear installation laid on the seabed, (18) is a fin-shaped lower conductive electrode attached to the cable (17), (19) is the cable (17) and It is a plate-shaped upper conductive electrode arranged in parallel above the lower conductive electrode (18), and an AC voltage is applied to both conductive electrodes (18) and (19) by an electric barrier generating power source (20). ,cable
An electric barrier having a predetermined electric field strength is formed around (17), and the electric barrier prevents large fish from approaching the cable (17).

(Examples 5 and 6) Further, as Examples 5 and 6, as the fin-shaped and plate-shaped electrodes (18) and (19) of Example 4, as shown in FIGS. A wire mesh (21) and a plurality of rods (22) bound by a binding body (23) may be used.

(Seventh Embodiment) Further, FIGS. 12 to 15 showing the seventh embodiment will be described.

In FIGS. 12 and 13, (24) is a cable as an underwater linear laying object, (25) is a plurality of fixing rings attached to the outer periphery of the cable (24) at regular intervals, and (16) is each Retaining ring
Eight support arms provided at equal intervals in (25), and (27) are supported by each arm (26) of each ring (25) to support the cable (2
4) 8 cable-like conductive electrodes arranged in parallel with each other, and every other conductive electrode (27) as the first group,
The conductive electrodes (27) of the second set are connected to one end of the power supply (28) for generating an electric barrier, and the remaining conductive electrodes (27) are used as the second set, and the conductive electrodes (27) of the second set. Is connected to the other end of the power supply (28), and the power supply (28) causes the first and second conductive electrodes (2
For example, an AC voltage is applied to 7), an electric barrier having a predetermined electric field strength is formed around the cable (24), and the electric barrier prevents large fish from approaching the cable (24).

The distribution of equipotential lines on the cut surface orthogonal to the cable (24) and each conductive electrode (27) is as shown in FIG. 14, and the lines AA ′ and BB ′ in FIG. The electric field strength distributions on the lines are as shown by the solid and broken lines in Fig. 15, respectively, and the distance on the horizontal axis indicates the distance from the center of the cable (24), one direction being positive and the other direction being negative. .

In each of the above-mentioned embodiments, the electric barrier generating power source (7),
AC voltage was applied by (11), (16), (20) and (28),
You may make it apply a DC voltage or a pulse voltage.

In addition, since current flows through the power cable connecting the power source for generating the electric barrier and the two conductive electrodes, there is no possibility that the shark or the like will damage the cable.

However, the power cable runs along the underwater linear construction,
It is desirable to lay it so that it lies within the area of influence of the protective electrical barrier formed by both conducting electrodes.

〔The invention's effect〕

As described above, according to the method for protecting an underwater linear structure of the present invention, since an electric barrier having a predetermined electric field strength for protecting the linear structure is formed around the underwater linear structure, a shark, etc. When a large fish of (1) approaches an underwater linear structure, it is possible to prevent the large fish from approaching the underwater linear structure by electrical stimulation by the electric barrier. It is possible to prevent damage, and it is possible to solve various problems such as deterioration of communication function and communication failure in the case of a communication cable, which is extremely effective.

[Brief description of drawings]

The drawings show an embodiment of a method for protecting an underwater linear laying material according to the present invention. FIGS. 1 and 2 are sectional views and perspective views of Embodiment 1, and FIGS. 3 and 4 are drawings of Embodiment 2. A perspective view and a sectional view, FIGS. 5 to 8 show a third embodiment, and FIGS. 5 and 6 are a perspective view and a sectional view, FIG. 7 and FIG.
The figure shows the relationship between electric field strength and distance, electric potential and distance,
FIG. 9 is a cross-sectional view of the fourth embodiment, FIGS. 10 and 11 are plan views of a part of the fifth and sixth embodiments, and FIG. 12 and the following drawings show a seventh embodiment. FIG. 13 is a sectional view, FIG. 14 is a distribution diagram of equipotential lines, and FIG. 15 is a relationship diagram between distance and electric field strength. (1), (8), (13), (17), (24) ... Cable, (5), (6),
(9), (10), (15), (18), (19), (27) ... Conductive electrode,
(7), (11), (16), (20), (28) ... power supply, (14) ... jacket, (21) ... wire mesh, (22) ... rod.

 ─────────────────────────────────────────────────── ─── Continued Front Page (72) Inventor Hiroyuki Carpenter 1-6-14 Edobori, Nishi-ku, Osaka City, Osaka Prefecture Hitachi Shipbuilding Co., Ltd. (72) Masahiko Yamamoto 1-6-14 Edobori, Nishi-ku, Osaka City, Osaka Prefecture Within Hitachi Zosen Co., Ltd. (56) Reference JP-A-53-73391 (JP, A) JP-A-63-157889 (JP, A) Jitsuko Sho-55-18889 (JP, Y2)

Claims (1)

[Claims] 1. A wire, wherein two conductive electrodes are arranged in parallel on an underwater linear installation such as a cable or rope laid in water, and a voltage is applied to both conductive electrodes by an electric barrier generating power source. A method for protecting an underwater linear structure, comprising forming an electric barrier for protecting the linear structure around the linear structure.