JPH09308037A - Method of laying subaqueous cable - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of laying a subaqueous cable, which can lay a subaqueous cable by selecting a smaller construction barge, even when a cable coil is enlarged. SOLUTION: This method is one which lays the subaqueous cable 8 loaded in coil form on a construction barge 1 on the bottom of the water by veering it out from the turret 23 and the sheave 3 on the construction barge via a tilt frame which has a guide part, and others and further from a shooter 5. Then, by using a guide-shaped member provided with an R for the guide part of the slant frame, the subaqueous cable 8 veered out of the sheave 3 is curved along the R of the said guide-shaped member, and then it is shifted to the shooter 5. This way, by using the guide-shaped member with an R, the horizontal distance (distance of bottom side) of the tilt frame can be substantially shortened. As the guide-shaped member, it will do to use a shoot pipe 11 with an R. For R, it will do to make it the tolerable bend radius or over of the subaqueous cable.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a technique for laying a submarine cable, and more specifically, it is a rigged laying boat that allows the submarine cable to be unwound from a yagura on a laying boat and laid on the water bottom. The method of laying a submarine cable according to. The term "water floor" is used as a concept that can include "sea floor".

[0002]

2. Description of the Related Art FIGS. 5 and 6 show a conventional example of a method of laying a submarine cable. In this method, the cable coil 1 stored in the container of the laying ship 1 is coiled and stored.
A submarine cable 8 from 0 is launched to the yagura 2 on the laying berth 1 and then fed out of the shooter 5 on the stern side through the sheave 3; the inclined mount 4 having the guide portion (roller group, etc.). It is laid on the bottom of the water. The outfitting on the laying ship 1 includes a brake device 7 and a tensiometer 6 in addition to the above-mentioned means. In addition, 9 is a center cage for kink prevention.

Therefore, when the berthing ship 1 is outfitted,
The height h of the yagura 2 is set to 70 to 80% of the maximum outer diameter of the cable coil from the upper portion of the cable coil 10. This is to secure a distance necessary for returning the twist to the underwater cable that was introduced when the underwater cable 8 was coiled. In addition, the tilt angle of the tilt mount 4 is 4 as a matter of experience.
0 ° or less is desirable.

[0004]

According to the above-mentioned prior art; according to the methods of FIGS. 5 and 6, there is no problem when the cable coil 10 is downsized, but when the cable coil is upsized, the inclination is increased. It becomes necessary to increase the horizontal length (base length) of the gantry 4. Therefore, in recent years, it has been necessary to select a large-sized laying barge in response to an increase in the size of the cable coil that occurs due to the long distance of the submarine cable, which causes a problem of high cost. In addition, in large-scale laying barges, the draft becomes deep and the distance of the levitation extension line in the submarine cable becomes long, and there is a great risk of causing a “kink phenomenon” that causes a small loop due to the twisting of the submarine cable during landing. There was also a problem.

Therefore, the problems (objectives) to be solved by the present invention
An object of the present invention is to provide a method of laying a submarine cable, which enables a smaller berth to be selected and used for laying a submarine cable even if the cable coil is enlarged.

[0006]

According to the present invention, there is provided a method for laying a submarine cable, wherein a submarine cable loaded in a coil on a laying boat is mounted on a laying boat; In the method of further extending from the shooter to the outside of the ship and laying on the water bottom via a guide-shaped member with an R attached to the guide portion of the inclined mount, the water-bottom cable fed from the sheave is connected to the R of the guide-shaped member. Bend along and move to the shooter. As described above, the use of the R-shaped guide member can substantially reduce the horizontal distance (the distance of the bottom side) of the inclined mount, and further enables the downsizing of the laying ship. .

A chute pipe with an R is preferably used as the guide member. It is recommended that R be equal to or greater than the allowable bending radius of the submarine cable.

The sheave is usually extended from the rising direction of the submarine cable to the unwinding direction of the submarine cable; from the center of the laying ship to the stern direction, but in some cases,
Extend at a right angle to the laying direction of the submarine cable, and extend the guide-like member (shoot pipe) from the extension end to the stern side on one of the left and right sides of the laying ship, or opposite to the laying direction of the submarine cable. The horizontal bending roller group is continuously connected to the extension end, and the guide member (shoot pipe) is extended from the opposite side of the roller group to the stern side on one side of the laying ship. May be.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows a preferred embodiment of a method for laying a submarine cable according to the present invention, and FIG. 2 shows a chute pipe as a guide member with a radius R used in the method.

The outfitting of the laying ship 1 according to this embodiment includes a yagura 2, a sheave 3 for guiding a cable, an inclined pedestal having a guide-like member 11 with an R, a braking device 7,
It consists of a tensiometer 6 and a shooter 5. When assembling the yagura 2, the maximum outer diameter of the cable coil 10 used for laying is measured, and the height of the yagura 2 is 70 to 80% of the outermost diameter of the cable coil from the upper part of the cable coil.
Set to. This is to ensure the distance required to untwist the cable when coiling it.

The sheave 3 is mainly used for fixing, but it is also possible to attach a rotating body to the surface of the sheave body to smoothly guide the cable.

The guide-shaped member 11 is used for smoothly lowering the submarine cable 2 that has been raised by the yagura 2 and passed through the sheave 3, and in this embodiment, as shown in FIG. It is installed on the inclined mount using a chute pipe. R is not less than the allowable bending radius of the submarine cable 2.

Between the lower end of the chute pipe 11 and the shooter 5 attached to the stern, a braking device 7 having a necessary gripping force for the cable, and a tensiometer 6 for controlling the tension applied to the cable during installation. Has been installed.

Now, a method of laying a submarine cable in the present embodiment in which the laying boat 1 is equipped as described above will be described. A cable coil 10 loaded so as to surround the center cage on the laying boat 1 will be described. To submarine cable 8
To the stern side via the sheave 3 and then slide to the chute pipe 11 along R to brake. It is fed out of the shooter 5 through the device 7 and the tensiometer 6 to the outside of the ship, and then extended to the bottom of the water and laid. In this way, the submarine cable 8
Since it is guided along a chute pipe 11 with a curve while being guided and then is extended to the outside of the ship, the cable guide length on the laying pontoon 1 and especially on the inclined mount is R
Can be made substantially longer, and even if the cable coil 10 becomes larger, the horizontal length of the inclined mount (base length)
The guide portion can be made shorter than in the case of a straight line, and the laying barge 1 does not have to be upsized.

FIG. 3 shows another embodiment of the method of laying a water-bottom cable according to the present invention. The difference from the embodiment of FIG. 1 is that the sheave 3 is perpendicular to the laying direction of the water-bottom cable 8. The point is that the chute pipe 11 is extended from the extended end to the stern side on one of the left and right sides of the laying ship.
Such an embodiment is effective when it is not possible to outfit the center part due to the deck space on the laying ship. 14
Indicates a residential area. Further, since it is the same as the chute pipe 11 retreating from the stern and moving to the cable coil 10 side as compared with the embodiment of FIG. 1, it is possible to further downsize the laying ship.

FIG. 4 shows still another embodiment of the method of laying a submarine cable according to the present invention.
3 is different from the embodiment of FIG. 1 in that the sheave 3 is extended in a direction opposite to the laying direction of the submarine cable 8 (direction toward the bow side), and a horizontally curved roller group 15 is continuously provided at the extended end thereof. The point is to extend the chute pipe 11 from the side opposite to 15 to the stern side on one of the left and right sides of the laying ship. By doing so, the chute pipe 11 is the same as that of the embodiment of FIG. 3 as well as that of the embodiment of FIG. 3 as it is retracted from the stern and moved to the side of the cable coil 10, so that the laying ship can be further downsized. Is.

[0017]

As described above, according to the method of laying a submarine cable according to the present invention, the guide portion of the gantry for turning up the tower and gradually lowering the submarine cable through the sheaves has a guide shape with R. By using the member (shoot pipe) to guide the water-bottom cable while curving along the R, the horizontal length (base length) of the gantry can be made shorter than the conventional one (FIG. 1), and Eliminates the need to upsize the laying barge. This keeps costs low, and because the berthing ship can be made smaller,
The draft of the laying berth becomes shallower, the shoreline can be brought closer, the kink of the cable can be prevented, and the safe underwater cable laying can be performed.

[Brief description of drawings]

FIG. 1 is a side view showing an embodiment of a method of laying a submarine cable according to the present invention.

FIG. 2 is a specific explanatory view of the shooter pipe shown in FIG.

FIG. 3 is a plan view showing another embodiment of the method of laying a submarine cable according to the present invention.

FIG. 4 is a plan view showing still another embodiment of the underwater cable according to the present invention.

FIG. 5 is a bird's-eye view illustrating an example of a conventional submarine cable laying method.

6 is a side explanatory view of the conventional example shown in FIG.

[Explanation of symbols]

 1 Laying ship 2 Yagura 3 Sheave 5 Shooter 6 Tensiometer 7 Braking device 8 Bottom cable 9 Kink prevention center cage 10 Cable coil 11 Shoot pipe

Claims (5)

[Claims] 1. A submarine cable loaded in a coil on a laying ship is laid on the bottom of the laying ship by feeding it from a sheave on the laying ship; a sheave from a sheave to a sloping mount having a guide section and outboard from a shooter. In the method, a method of laying a water-bottom cable, which uses a guide-shaped member having an R on the guide portion of the inclined mount, bends the water-bottom cable fed from the sheave along R of the guide-shaped member, and then moves the shooter to the shooter. . 2. The method of laying a submarine cable according to claim 1, wherein a chute pipe having an R is used as the guide member. 3. The method of laying a submarine cable according to claim 1, wherein R of the guide member (shoot pipe) is equal to or larger than an allowable bending radius of the submarine cable. 4. The sheave is extended at right angles to the laying direction of the submarine cable, and a guide member (shoot pipe) is extended from the extended end to the stern side on one of the left and right sides of the laying ship. The method of laying a submarine cable according to any one of claims 1 to 3. 5. The sheave is extended in a direction opposite to the laying direction of the submarine cable, a horizontally curved roller group is continuously provided at the extended end, and a guide-like member (shoot) is provided from the opposite side of the roller group. The method for laying a submarine cable according to any one of claims 1 to 3, wherein the pipe is extended to the stern side on one of the left and right sides of the laying ship.