JPS6124893B2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention is a method in which, when launching a cable from the seabed to a floating plant, the cable is temporarily attached to a buoy installed in the sea, and then the floating plant is launched. This is a method for setting up cables for floating plants that makes it possible to relieve stress. In recent years, floating plants have been used for various purposes such as power plants, garbage incinerators, docks, and crude oil storage facilities.
If power is to be supplied to or from the flotation plant from another location, it is necessary to run power cables to the flotation plant.

Floating plants generally move horizontally and vertically due to tidal currents, waves, wind direction, tidal differences, etc. In the case shown in Figure 2, the shape of the power cable catenary changes, for example, Unreasonable stress is generated, and there is an extremely high possibility that this will lead to accidents such as cable breakage or insulation breakdown.

Also, due to the movement of the floating plant 12, the cable 11 will draw a catenary, but as the tension of the cable increases, the cable 11 on the seabed will
is pulled towards the floating plant 12 due to the increased tension and moves little by little, so that the cable 1
This is because the cable 11 is subject to wear on the seabed, and the shape of the catenary gradually deforms, which increases the possibility that the cable 11 will kink or collide with the floating plant 12.

The present invention aims to eliminate such drawbacks by providing a method for erecting a cable for a floating plant as set forth in the claims, and an embodiment of the present invention is shown in FIG.

To explain based on FIG. 1, the buoy 3 is anchored in the sea between the bottom point of the cable 1 and the floating plant 2 by one or more anchor chains 4 and anchor bases 5.
Once the cable 1 is launched to the buoy 3 and then fixed to the cable gripping device 6, the cable 1 is launched to the floating plant 2. This makes it possible to relieve mechanical stress such as tension generated in the cable 1, thereby preventing wire breakage and dielectric breakdown accidents.

Note that local stress concentration in the cable 1 is prevented by employing a metal or rubber/plastic bending plate or bending tube (bellmouth type or bushing type) as the cable bending limiting device 7.

Further, by providing the cable gripping device at a location opposite to the buoy 3, sandwiching the bottoming point 11, the cable 1 is prevented from moving on the seabed.

In this way, the present invention allows the cable to be attached to the buoy at once, increasing the number of cable catenaries, reducing the cable weight of each catenary, and preventing the cable from being perpendicular to the cable at the cable support section at the upper end of the catenary. Since the angle between the cable and the wire can be made smaller, the tension generated in the cable can be reduced.

In addition, by submerging the buoy in the sea, the current
Because it is less affected by waves, wind direction, and tides, it is possible to reduce cable swing, twist, and tension caused by these.In addition, by installing a cable bending restriction device, the cable does not bend unreasonably, and stress concentration at the cable gripping part is reduced. It can be reduced.

Furthermore, since the cable retaining device is fixed to the seabed and the cable is secured thereto, the cable does not shift on the seabed, and therefore there are various effects such as no wear on the cable.

It goes without saying that the present invention is not limited to power cables and control cables, but can also be appropriately applied to communication cables, oil pipes, water pipes, and gas pipes.

[Brief explanation of the drawing]

FIG. 1 is a front view showing an embodiment of the present invention, and FIG. 2 is a front view showing an embodiment without a buoy. The numbers in the diagram are 1 and 11 are cables, 2 and 12 are
is a flotation plant, 3 is a buoy, 4 is an anchor chain, 6 is a cable gripping device, 7, 13 is a cable bending restriction device, 8 is a cable restraining device, 9, 14
indicates the sea surface, and 10 and 15 indicate the ocean floor.

Claims (1)

[Scope of Claims] 1. A cable to be held on the seabed is held on the seabed by one or more chains and once anchored by a catenary to a buoy floating in the sea. A method for starting up a cable for a floating plant, characterized by restoring the catenary and locking it to the floating plant. 2. The buoy and the floating plant are provided with a cable bending limiting device that limits the bending of the cable, and the cable is latched to the buoy and the floating plant through the cable bending limiting device, as set forth in claim 1. How to set up cables for floating plants.