JPH08168149A - Submarine cable laying vessel and cable landing method - Google Patents

Abstract

PURPOSE: To obtain a submarine cable laying vessel and a cable laying method useful for shortening the work schedule and reducing the expense. CONSTITUTION: More than one set of a cable tank and a cable trough for pulling up and guiding a landing cable contained in the tanks are installed on the deck of a cable laying vessel and. The landing cable and the cables assembled in the trough are held integrally using a wire or the like by means of a lashing machine 3. A plurality of landing cables lashed by means of the lashing machine 3 is hauled by a cable engine 4 and thrown into the ocean through a stern shoot 6 disposed at the stem or stern of the cable laying vessel. The lashing machine 3 has a split rotary head and one cable can be branched arbitrarily from the plurality of cables to be lashed and thrown into the ocean simultaneously with others.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the laying of a submarine cable or the like for connecting continents via the ocean, and particularly to the laying of a submarine cable particularly useful for pulling a submarine optical cable to a land station. It relates to ships and landing methods.

[0002]

2. Description of the Related Art When a submarine cable laid via the ocean or a harbor is landed at a landing station, a work vessel A equipped with necessary equipment as shown in FIG. A ship capable of performing such work is simply referred to as a submarine cable laying ship) and operates between a predetermined position B offshore of the Landing Bureau and the coast C of the Landing Bureau and floats on the cable D for landing. With the mark attached, the ship is towed to the shore and the submarine cables are being landed.

By the way, the landing station for submarine cables constructed on beaches is equipped with terminal equipment for landing a plurality of submarine cable main lines that are normally sent across the ocean. When landing these main lines of submarine cables, it was customary to carry out the landing work individually for each submarine cable by the operation work of the laying ship as described above.

That is, in view of the handling property of the submarine cable, the cable is landed for each line, and the subsequent laying work is performed, and then the submarine cable is protected from fishing and man-made obstacles. The work of burying at 0.5m to 1.5m is performed.

[0005]

However, when a plurality of submarine cables are landed one by one as described above, there are many problems as described below. (1) If multiple cables are used for landing each line, the construction period will be relatively long and the construction cost will increase accordingly. That is, the landing work usually starts with the preparation work of the station building and the beach area, and then consists of the landing work and the restoration work. Of these, the preparatory work includes the work of opening and closing the cable pipes that lead from the beach to the station building, and the work of opening and closing the route for the cables on the premises, etc. Depending on the landing station, there is usually a two-week deadline. (2) Further, the landing work is carried out by solidifying the ship offshore, but because it is easily affected by the weather, it may be washed away by bad weather to guide the cable terminal from the ship to the shore, or from a regular laying route. It comes off. Even after the completion of the preparation work, the landing work may be delayed depending on the weather. (3) For the restoration work, bury the cable in the part that was excavated in the preparatory work, provide the necessary protection, and backfill. Furthermore, in order to protect the laid cables from obstacles such as fishing, it is necessary to bury the cables under the sea floor.These constructions are carried out continuously. Depending on the time, it will take about 3 months.

In the conventional construction method as described above, such various works and works are carried out for each landing of one cable, and if the three cables are landed, a total of 9
It requires a period of months, and the total construction cost increases due to the long construction period. In this way, it is necessary to secure the laying area in the water area in front of the landing station for a long period of time.However, existing cables may be buried in this water area in order to prevent damage to these cables. Construction work is limited. In addition, there may be a problem in the position where the work boat is consolidated when landing.

Therefore, in order to solve these problems, it is considered that a plurality of landing cables are bundled into one cable at the time of manufacturing a submarine cable and the landing operation is performed. However, if the submarine cable landing operation is performed once at the landing station where a plurality of cables are bundled at the manufacturing stage, the following problems occur.

Usually, a single armored cable can be wound with a minimum radius of curvature of about 1.5 m and is easy to handle, but when three such cables are bundled together, the radius of curvature is 5 m or more. You need to wind it up. Then, when installing such a cable on a laying ship, a cable tank with a very large radius is required, and a corresponding laying ship is required, which increases the economic burden.

[0009] Further, the increase in weight of such a cable makes it difficult to carry out the shipment from the factory and the loading operation of the cable, and the cable may be damaged. Furthermore, even if one cable fails during landing work, the whole cable is bundled in advance, so repairs that interrupt the cables cannot be made, and the landing work must be performed again. There is a problem that landing work will be prolonged.

[0010]

The present invention solves these problems all at once, and achieves a landing method that is less expensive and more reliable than conventional methods, and is therefore used as a laying ship. Two or more cable tanks to accommodate submarine cables,
A first cable guide that collects a submarine cable pulled out from the cable tank at a predetermined position, a lashing device that winds a binding wire around the submarine cable that is collected by the first cable guide, and the lashing With a cable engine that pulls out the above-mentioned submarine cable integrated by the device at a predetermined speed,
The submarine cable drawn from this cable engine is guided so that it can be dropped into the sea from the bow or stern.

Further, the lashing device includes a trough portion through which at least two submarine cables pass, a cylindrical rotary head portion which rotates around the trough portion about the traveling direction of the cable, and a submarine cable. A wire for restraining is wound around the bobbin, which rotates together with the rotary head portion, and an electric motor that rotates the head portion at a predetermined rotation speed. The rotary head portion is configured to be separable into two parts in case the cable breaking operation is required especially when bundling the cables.
Further, the present invention bundles the submarine cables integrated with wires by such a submarine cable laying ship from the sea near the landing station to a predetermined distance offshore, or conversely, from offshore to the vicinity of the landing station for landing. The present invention provides a landing method in which two or more submarine cables are unloaded at one time by laying the cable and connecting the submarine cable main line and the integrated exterior cable for landing.

[0012]

With the lashing device provided on the laying ship, a plurality of single landing cables pulled out from the cable tank are bundled together and restrained with wires or the like to be dropped onto the sea. The lifting cable can be routed to the beach by a single operation, and various operations thereafter, such as burying the cable, pulling up, and restoration work, can be integrated at the same time. for that reason,
The construction period is shortened and the occupation period of the work area near the landing station is shortened, resulting in great economic benefits.

[0013]

1 is a side view of a main part of a submarine cable laying vessel for realizing a landing method for a submarine cable of the present invention, particularly a submarine optical cable, and FIG. 2 is a top view of FIG. It shows an overview of various outfitting equipment that we saw. The three circles shown in the center of this figure are the cable tanks 1 (A, B, C) in which the submarine cables for landing are housed in a coil shape, and 2 (A, B). , C) are cable troughs that guide and guide the submarine cables pulled up from the cable tanks 1 (A, B, C). In the case of this embodiment, the number of submarine cables for landing is three, and in particular, the cable trough 2C is of a scale that allows three submarine cables to pass while descending.

A cable trough 2C for moving this cable
A lashing device 3 (also referred to as a cable collecting device) for collecting cables, which will be described later, is arranged on the outlet side of each of the cable tanks 2 (A, B, C). For example, three submarine cables are constrained by wires or the like so as to be integrated as one cable. 4 is a lashing device 3
Is a cable engine for moving the integrated cable by a predetermined speed. The cable engine 4 pulls the cable according to the operating speed of the laying ship and supplies it to the dynamo device 5 for the next tension measurement. To do. Then, the dynamo device 5 controls the tension at the time of dropping the cable to a predetermined value, and the cable is dropped onto the ocean through the stun chute 6 provided at the stern (the bow). .

The cables gathered for landing simply pass through the lashing device 3 while being pulled by the cable engine 4, and it is not necessary to maintain the tension of the cables in the lashing device 3. ing. In addition, the cable engine 4 is a sub-cable engine 4 used when it is necessary to branch a part of the submarine cable restrained by a wire so as to be stretched later and to drop it independently.
A is provided so that a landing cable can be branched at an arbitrary location so that it can be dropped as a two-row landing cable from the second stun chute 6A.

Next, an outline of the above-mentioned lashing device 3 will be described with reference to FIGS. FIG. 3 shows a case where the lashing device is viewed from its side, and 10 is a base and 1
Reference numerals 1 and 12 denote cable guides for the first and second cable guides arranged upright at both ends of the base. The cables are provided above and below the cable guides 11 and 12 in the vertical and horizontal directions. A pair of rollers for restricting and guiding is provided.

Reference numeral 13 denotes a support base for holding a collecting machine for winding the restraining wires 21 around the three cables 20 collected by the second cable guide 12. The electric motor 14, a cylindrical head 15 rotationally driven by the electric motor 14, and a trough portion 13A (FIG. 4) through which the three cables pass are supported. The head 15 is composed of a plurality of small rollers 16, 16, 16 ...
.. by contacting the cylindrical rails provided on both sides of the trough 13A and rotating in a plane orthogonal to the traveling direction of the integrated cable 20 as shown in FIG. Is held.

FIG. 4 shows a cross section of the head 15. The cylindrical head 15 has a small gear 14A which meshes with a ring gear provided on one side end surface, and the small gear 14A.
Is driven by a large gear 14B which is connected by a chain and the rotary shaft of the electric motor 14 is connected. The trough portion 13A fixed to the support base 13 is arranged so that the three cables 20 can pass therethrough. Further, two bobbins 1 are provided on the outer peripheral side surface of the cylindrical head 15.
7 and 17 are rotatably mounted, and the wire 21 wound around the two bobbins 17 and 17 is paid out from the rotating guide rollers 18 and 19 together with the head 15 under proper tension. I am trying to do it.

In the cylindrical head 15 of the lashing device 3 mounted on the laying ship of the present invention, as shown in FIG. The point is used as a hinge so that the point Z is opened upward and can be opened as shown by a dotted line. And
In this open state, any one of the submarine cables 20 passing through the trough portion 13A can be pulled out from the outer periphery of the head 15 as shown by an arrow V in FIG. Is designed. Note that FIG. 5 is a perspective view showing this open state, and the same portions as those in FIG. 4 are designated by the same reference numerals.

Therefore, as shown in FIG.
The three cables 20 which are guided from the side of the cable guide 12 and are passing rightward through the trough portion 13A in the head 15 are rotated around the bobbin 17 by the rotation of the head 15 during the passage. Wire 2 unrolled from
The cable 1 wound around and bound by the wire 21 and integrated is pulled out from the first cable guide 11 by the cable engine 4 described above as a single-strand cable.

Then, a cable of one line is dropped from the stun chute 6 on the ocean and laid as a submarine cable for landing from offshore to the beach. It should be noted that by providing a float at the time of dropping, the cable can be towed to a predetermined position and settled later.
If necessary during this laying work, the cable dropping is temporarily stopped, and a part of the head (15A) of the above-mentioned lashing device is stopped.
To branch off, for example, one cable 20A is moved from the trough 13A to the outside. Then, after that, a part of the head (15A) is closed again and fixed by a fixing metal fitting (not shown), and the wire 21 is wound around the remaining two cables by operating the lashing device,
It can be operated like dropping into the ocean. By dropping the ocean while simultaneously pulling the branched cable by the multiple cable engine 4A, the landing of the submarine cable can be achieved by one operation of the laying ship.

Although the present invention has been described with respect to the case where three landing cables are laid at once, the present invention can be applied to the case of two or four cables. However, in general, when three cables are constrained and laid, the handling as a single-strand cable is the most stable, so for example, in the case of two cables, use a dummy cable to collect three cables as much as possible. A cable is preferable. Wire 21 has a radius of 3.2 mm
About 900 m can be accommodated in the bobbin, but the wire 21 can be replaced by a restraining rope. The winding pitch is 1 to 2
It is preferably m.

[0023]

As described above, in the submarine cable laying ship of the present invention, two or more cables are assembled and integrated with respect to the laying of a landing cable for landing a coastal submarine cable on land. Since the lashing device is installed and the cable pulled out from the cable tank is laid by one operation, various construction periods required for conventional landing work can be significantly shortened and the construction cost can be halved. Alternatively, it is possible to exhibit an excellent effect that it can be reduced to a fraction.

Further, since the cables can be buried in the seabed while being bundled, a plurality of cables can be buried and restored at the same time, so that the construction cost can be remarkably reduced and the cables can be installed in the cable laying area. The period of hindrance to existing fisheries is shortened. In addition, there is a margin in the cable laying route in the water area in front of the Landing Bureau, and it is possible to widen the gap with the existing cable, so there are few accidents that damage the existing cable.

Further, the landing method using the laying ship of the present invention has the effect of reducing the construction period and the construction cost as described above, and in addition to increasing the number of landing submarine cables to be expanded in the future. There are significant economic advantages as well, as forecasts can be captured and the plan achieved without incurring significant cost increases.

[Brief description of drawings]

FIG. 1 shows a side view of a main part of a submarine cable laying ship of the present invention.

FIG. 2 shows a view of the undersea cable laying ship of the present invention as seen from above.

FIG. 3 is a side view showing an outline of a lashing device equipped on a laying ship.

4 is a cross-sectional view of a part of the lashing device of FIG.

FIG. 5 is a perspective view when a part of the submarine cable restrained by the lashing device is taken out.

FIG. 6 is an explanatory diagram showing an outline of landing of a submarine cable.

[Explanation of symbols]

 1 (A, B, C) Cable tank 2 (A, B, C) Cable trough 3 Lashing device 4 (4A) Cable engine 5 (5A) Stanchute 11, 12 11th and 2nd cable guide 14 Electric motor 15 Head 20 Submarine cable for landing 21 Wire

 ─────────────────────────────────────────────────── ─── Continued Front Page (72) Masakazu Nasu 2-3-2 Nishishinjuku, Shinjuku-ku, Tokyo International Telegraph and Telephone Corporation (72) Ikuo Maruume 2-3-3 Nishishinjuku, Shinjuku-ku, Tokyo No. 2 International Telegraph and Telephone Corporation (72) Inventor Yukihiro Fujii 2-3-2 Nishishinjuku, Shinjuku-ku, Tokyo International Telegraph and Telephone Corporation

Claims (5)

[Claims] 1. Two or more cable tanks for accommodating a submarine cable, a first cable guide for collecting a submarine cable drawn out from the cable tank at a predetermined position, and a first cable guide for collecting the submarine cables. A lashing device that winds a restraining wire around the submarine cable, a cable engine that pulls out the submarine cable integrated by the lashing device at a predetermined speed, and guides the submarine cable that is pulled out from the cable engine. An undersea cable laying ship, which is equipped with a stun chute for dropping into the sea from the bow or stern. 2. The lashing device comprises a trough section through which at least two submarine cables pass, a cylindrical rotary head section which rotates around the trough section about the traveling direction of the cable, and a submarine cable. The bobbin, which is wound with a wire for restraining it and is rotating together with the rotary head portion, and an electric motor for rotating the head portion at a predetermined rotation speed. Submarine cable laying ship. 3. The submarine cable laying ship according to claim 2, wherein the rotary head portion is configured to be separable into two in order to remove at least one cable passing through the trough portion. 4. The submarine cable laying ship according to claim 3, wherein the electric motor has a rotational speed that is variable in accordance with the speed at which the submarine cable is pulled out. 5. The submarine cable which is integrated with a main line of the submarine cable by laying a single submarine cable integrated with a wire by the submarine cable laying ship at a predetermined distance from the sea near the landing station and offshore. A landing method for submarine cables, characterized in that two or more submarine cables are unloaded at one time by connecting to each other.