JPS6149886B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an underwater cable installation method that can shorten the installation period when power cables, communication cables, etc. are installed on the seabed, lakebed, riverbed, etc.

When laying cables such as power cables and communication cables on the seabed, lakebed, riverbed, etc., it is necessary to lay the cables on the bottom of the water to prevent them from being damaged by fishing gear, anchors of ships, etc. It is common to bury it. The installation speed in that case varies depending on various conditions, but it is 100 to 1000 m per day.
Therefore, if the length of the cable laying route is, for example, 20 km, the number of days required for the cable laying work will be 20 to 200 days, which is a long period of time. During the installation period, the sea area or water area along the installation route is occupied, which has the disadvantage of interfering with fishing vessels or ships navigating near the installation route. In addition, since the installation period is long, ranging from 20 to 200 days, there is a high possibility that bad weather will occur during cable installation, and if bad weather occurs, there is a risk that the cable will be cut and a long length of cable installation will not be possible. The disadvantage was that it was expensive.

The present invention improves the above-mentioned drawbacks, and its purpose is to shorten the cable installation period. Examples will be described in detail below.

FIGS. 1 to 3 are explanatory diagrams of embodiments of the present invention, in which A and B are construction ships, 1a and 1b are cable coils, 2a and 2b are turrets, 3 is a cable, and 4a and 4b.
5a, 5b are hauling machines, 6a, 6
7a and 7b are stern curve rollers, 8a and 8b are center cages, 9 is a temporary coil machine, 10a and 10b are anchors, and 11
Reference characters a and 11b are towing lines, 12a and 12b are laying and burying machines, and 13a and 13b are conduits. Note that the same reference numerals represent the same parts in FIGS. 1 to 3.

Move the laying ship A, which has coiled cable 3 of a length corresponding to the length of the laying route, to the center of the laying route, and move the laying ship B, which has a cable loading capacity of at least 1/2 of the cable loading capacity of the laying ship A, to the center of the laying route. As in the case of laying vessel A, the anchors 10a, 10 are moved to the center of the laying route as shown in FIG.
Use b to fix the ships so that their sterns face each other. Next, the hauling machines 5a and 5b are operated, and the cable 3 that was coiled on the laying ship A is
is sent to the laying ship B via hold curve rollers 4a, 4b and temporary transfers with rollers 6a, 6b,
The tip of the cable 3 is sent into the hold of the laying ship B. In the laying ship B, when the tip of the cable 3 is sent into the hold, the temporary coil removal machine 9 is operated to remove the coil from the cable 3. In this way, once half of the cable 3 loaded by the laying ship A has been transferred to the laying ship B and coiled, the temporary coiling machine 9 and the hauling machines 5a and 5b are operated and the cable 3 is wound. After that, temporary coil removal machine 9, temporary transfer with rollers 6a, 6b
to be removed. Note that instead of the temporary coil take-up machine 9, a turn table (not shown) may be used to wind the coil thereon.

Next, as shown in FIG. 2, the anchor 10a of one of the laying vessels, for example, laying vessel A, is reeled in and paid out, and the laying vessel A is gradually separated from the laying vessel B, and at the same time, the hauling machine 5a is operated. The coiled cable 3 is let out into the water via the hold curve roller 4a and the stern curve roller 7a, so that the cable 3 lands on the bottom of the water as shown.

Next, as shown in FIG.
a, 12b to the bottom of the water, and the laying ship A,
Engage the anchors 10a and 10b of B. The cable laying and burying machines 12a and 12b are connected to the cable laying vessel A and
It is connected to B. Thereafter, the laying vessels A and B are moved toward both ends of the laying route, and the hauling machines 5a and 5b and the laying and burying machines 12a and 12b are operated. The hauling machines 5a, 5b feed out the coiled cable 3 into the water via the hold curve rollers 4a, 4b and the stern curve rollers 7a, 7b, and the cable laying machines 12a, 12b dig a groove and fill the groove. Lay and extend cable 3.

In this way, the two laying vessels A and B are moved from the center of the laying route toward both ends of the laying route,
By laying and extending the cable 3 using these two laying vessels A and B, it becomes possible to shorten the laying period.

FIG. 4 is an explanatory diagram of another embodiment of the present invention,
This figure shows the cable 3 being transferred from the installation ship A to the installation ship B. In the same figure, 14
1 is a temporary tower, 15 is a temporary hauling machine, and 16 is a curved roller, and the same reference numerals as in other FIGS. 1 to 3 represent the same parts.

In this case as well, as described above, the installation ship A, which has coiled the cable 3 of the length corresponding to the length of the installation route, is moved to the center of the installation route, and at least 1/2 or more of the cable loading capacity of the installation ship A is moved. Laying ship B, which has a cable loading capacity, is also moved to the center of the laying route, and both laying ships A and B are brought alongside.
Next, a temporary turret 14 is installed on the laying ship A, and a temporary hauling machine 15 is installed on the temporary turret 14. After that, the temporary hauling machine 15 was operated, and the cable 3 that had been coiled by the laying ship A was
is sent to the hold of the laying ship B via the hold curve roller 4a, temporary hauling machine 15, and curve roller 16, and the temporary coil removal machine 9 is operated to remove the coil from the cable 3. In this way, the cable 3 that was loaded by the laying ship A on the laying ship B
When half of the coils have been removed, the temporary tower 14, the temporary hauling machine 15, and the temporary coil removal machine 9 are removed, and the anchors 10a and 10b are reeled in.
Move the laying vessels A and B so that their sterns face each other. Thereafter, the cable 3 is sunk to the bottom of the water, the laying machine is landed on the bottom of the water, and the cable 3 is laid and extended on the bottom of the water in the same manner as described above.

In the embodiment, the laying vessels A and B were moved to the center of the laying route and the cable 3 was transferred from the laying vessel A to the laying vessel B, but the laying speed of the laying vessels A and B was If the cables 3 and 3 are different, it is desirable to decide the position where the cable 3 is to be transferred, taking into account the installation speed of each cable.

As explained above, in the present invention, the cable is laid by two laying vessels A and B, so it is different from the conventional cable laying method in which the cable was laid by one laying vessel. There is an advantage in that the installation period can be shortened in comparison. Also, the cables are not connected at sea, and the cables are connected from the laying ship A to the laying ship B.
This method has the advantage of improving work efficiency compared to the method of connecting cables at sea because half of the amount can be transferred to another location.

[Brief explanation of the drawing]

FIGS. 1 to 3 are explanatory diagrams of an embodiment of the present invention,
FIG. 4 is an explanatory diagram of another embodiment of the present invention. A and B are laying vessels, 1a and 1b are cable coils, 2a and 2b are turrets, 3 is cables, 4a and 4b
is a hold curve roller, 5a and 5b are hauling machines, 6a and 6b are temporary bridges with rollers, 7a,
7b is a stern curve roller, 8a, 8b is a center cage, 9 is a temporary coil taker, 10a, 10b is an anchor, 11a, 11b is a towing line, 12a, 1
2b is a laying and burying machine, 13a and 13b are conduit pipes, 1
4 is a temporary turret, 15 is a temporary hauling machine, 16
is a curved roller.

Claims (1)

[Claims] 1. A first laying ship loaded with a cable of a length corresponding to the length of the laying route is moved to a position approximately half way along the said laying route, and at that position, approximately half the length of the cable is The cable is transferred from a first laying ship to a second laying ship, and the cable is paid out and laid while moving the first and second laying ships in opposite directions toward the ends of the laying route. Underwater cable installation method.