JPH078095B2 - Submarine cable repair method and terminal waterproofing apparatus used in the method - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method for repairing an accidental portion of a submarine cable.

[Prior Art] As shown in Fig. 3 (a), when the submarine cable (CV or OF cable) 1 is injured by an anchor of a ship, etc., the injured part is removed and the result is shown in Fig. 3 (b). Thus, it is necessary to perform the interruption and connection 5 using the other spare cable 4.

Conventionally, such a repair method has been to load a crane on a connecting work ship (barge), place this ship on the accident cable, and pull up the cable on the ship by the crane to perform disconnection and interrupt connection, or use the OF cable. For cables with internal hydraulic pressure, the area near the damaged cable is cut in the sea, and then the cable is lifted up on the work boat for interrupt connection.

[Problems to be Solved by the Invention] However, in the conventional method, when a damaged cable is pulled up on a ship by a crane, the pulling length of the cable in the sea is long and the pulling force is large. It was also difficult to operate the work boat.

Also, in the case of OF cable, the hydraulic pressure of the onshore pressure oil tank may drop and seawater may invade, so it was necessary to disconnect the cable many times while checking the ingress status of seawater on board. When seawater invades the cable, the electrical characteristics deteriorate, so it is necessary to waterproof the cable during and after cutting.

The object of the present invention is to solve the above-mentioned problems of the prior art,
It is to provide an easy and reliable method of repairing an undersea cable.

[Means and Actions for Solving the Problem] In order to achieve the above object, the present invention cuts a submarine cable in an underwater capsule having an air chamber installed in the sea,
After attaching a waterproof metal fitting to the cut end of the cable and pulling it up to the sea, the cable is connected to another cable on the work boat using a connecting material having a waterproof structure, and the cable is sunk again on the seabed. It is intended to prevent the intrusion of seawater and to ensure stable quality work.

Further, according to the present invention, there is provided a terminal waterproofing apparatus which advantageously advances the repair method, which is a cap-shaped terminal waterproof metal fitting covering a cut end surface of a cable and a circumference of a cable end portion continuing to the cable, and the metal fitting. A packing provided on the inner bottom surface of the terminal and pressed against the cut end surface of the cable, a waterproof compound filled between the body of the terminal waterproof fitting and the outer surface of the cable, and the opening-side end of the terminal waterproof fitting. And a cable, and a pressing metal fitting that is loosely inserted onto the cable so as to be movable in the axial direction and screwed to the outer circumference of the opening side end portion of the terminal waterproof metal fitting.

It is possible to provide a terminal waterproofing device, particularly for an OF cable, which has a tapered projection that is press-fitted into the oil passage from the cable cut end surface on the inner bottom surface of the terminal waterproof metal fitting.

According to such a device, it is possible to perform a reliable waterproofing process in a short time especially on the seabed where the working conditions are not good.

[Embodiment] An embodiment of the present invention will be described below in the order of work, with reference to the drawings.

As shown in FIG. 1, the underwater capsule 8 is installed using a weight 12 at a position where the undersea cable 9 is cut.

An air compressor 7 on the work boat 6 in the capsule 8.
To send compressed air through the air hose 7a.

Compressed air is sent into the capsule 8 to form an air chamber 10, and the submarine cable 9 is pulled up to the air chamber 10 to wipe the cable surface well so that no seawater remains.

 The cable 9 is cut using a bow saw or the like.

After cutting the cable 9, a terminal waterproof metal fitting 12 as a terminal processing device shown in FIG. 2 is attached.

In case of OF cable, taper protrusion 12b is attached to the inside of terminal waterproof metal fitting 12 and press-fitted into the oil passage, and the taper (rubber) packing 13, (rubber) packing 14 and waterproof compound 15 are used. Attach to the end of.

The terminal waterproof metal fitting 12 is prevented from slipping off by tightening the tapered (rubber) packing 13 with the pressing metal fitting 12a to increase the friction at the interface with the submarine cable 9.

After the end portion is treated as described above, the submarine cable 9 is pulled up onto the work boat and connected to another interrupt cable.

After the connection work is completed, the repaired cable is sunk on the original seabed.

[Effects of the Invention] According to the present invention as described above, since the submarine cable is cut in the underwater capsule, the cutting work can be performed in the same state as at sea, there is no flooding during cutting, and particularly for a cable that is not a watertight structure. Greatly effective for repair and recovery.

Further, since the repair work can be divided into the disconnecting work and the connecting work, it is possible to perform the work depending on the tide stop and tidal wind.

Furthermore, since there is no infiltration of water during cutting of the cable and pulling to the sea, it is almost unnecessary to take a cable length for confirmation of inundation at sea.

Furthermore, waterproofing of the terminal after cable cutting can be reliably performed in a short time, and work under the seabed becomes easy.

[Brief description of drawings]

FIG. 1 is an explanatory view showing an embodiment of the present invention, (a) is a front view, (b) is a side view, and FIG. 2 is a partially longitudinal side view showing a terminal sealing means after cutting a submarine cable, FIG. 3 (a) is an explanatory view showing the relationship between the accident part and the disconnection part before repairing the cable,
FIG. 3B is an explanatory diagram showing the relationship between the interrupted cable and the connection portion after the cable is repaired. 1: Accident area, 2: Submarine cable, 3: Cable cut point, 4: Interrupted cable, 5: Interrupted connection section, 6: Work boat, 7: Compressor, 7a: Air hose, 8: Underwater capsule, 9: Submarine Cable, 10: Air chamber, 11: Weight, 12: Terminal waterproof fitting, 12a: Press fitting, 13: Tapered rubber packing, 14: Rubber packing,
15: Waterproof compound.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Mikio Umezaki 5-1-1 Hidakacho, Hitachi City, Ibaraki Prefecture Hitachi Cable Co., Ltd. Hidaka Plant (72) Inventor Yoshio Ito 5 Hidakacho, Hitachi City, Ibaraki Prefecture 1-1-1 Hitachi Cable Co., Ltd. Hidaka Factory

Claims (3)

[Claims] 1. A submersible capsule equipped with an air chamber is installed in the sea, a submarine cable is cut in the air chamber, a waterproof metal fitting is watertightly attached to the cut end of the cable, and the cable is pulled up to the sea. A method of repairing a submarine cable, which comprises connecting the cable to another cable on a ship using a connecting material having a waterproof structure, and then submerging the cable again. 2. A cap-shaped terminal waterproof metal fitting that covers the cut end surface of the cable and the circumference of the cable end portion connected to the cable, packing provided on the inner bottom surface of the metal fitting and pressed against the cable cut end surface, and the terminal waterproofing. A waterproof compound that is filled between the body of the metal fitting and the outer surface of the cable, a tapered packing that is press-fitted between the open end of the terminal waterproof metal fitting and the cable, and on the cable in the axial direction. A terminal waterproofing device for use in a method of repairing a submarine cable, which comprises a metal fitting that is loosely inserted in a movable manner and is screwed to the outer periphery of the opening side end of the terminal waterproof metal fitting. 3. The terminal waterproofing device according to claim 2, particularly for an OF cable, which has a tapered projection that is press-fitted into the oil passage from the cable cut end surface on the inner bottom surface of the terminal waterproof metal fitting.