JP4488357B2 - Submarine tubular body laying system - Google Patents

Description

  The present invention provides a target tubular body laying line that is set on the seabed by submerging the tubular body in the sea while towing a pontoon on which a flexible tubular body such as a submarine cable is mounted by a dredger. The present invention relates to a submarine tubular body laying system that is laid along the seam. Since the present invention is suitable for laying a submarine cable for power transmission on the seabed, the following description will be mainly given of laying a submarine cable.

In general, when laying the submarine cable, the towed ship is towed by a tugboat through a tow rope, and the submarine cable mounted on the trolley is thrown into the sea. A method of laying along a cable laying line is employed (see, for example, Patent Document 1).
JP 7-298441 A

  By the way, when towing a tow by pulling a tow rope as in the prior art, the tow method tends to swing in the width direction of the ship due to the flow of tides, transverse waves, etc. There exists a possibility that a cable may shift | deviate from a target cable laying line, and there exists a problem that a laying precision is low. In particular, when laying submarine cables in places where obstacles such as bedrock are scattered on the seabed, zigzag cable laying is performed to avoid these obstacles. Improvement of laying accuracy is required.

  The present invention has been made in view of the above-described conventional situation, and provides a submarine tubular body laying system that can ensure the laying accuracy of a submarine cable even when a trolley swings due to a tide flow or a transverse wave. The purpose is that.

According to the first aspect of the present invention, there is provided a thruster which is disposed at an appropriate position of a base ship towed on the sea and which is assumed on the sea in correspondence with a thruster for stabilizing the hull position and a target tubular body laying line on the sea bottom. Output control means for controlling the output of the thruster so that the trolley is positioned on a ship towing line, and a flexible tubular body mounted on the trolley in a wound state is submerged in the sea and placed on the seabed. In the submarine tubular body laying system designed for laying,
The thruster is disposed in a housing portion formed so as to be stepped upward at four corner portions located on the left and right sides of the bow side and the stern side of the bottom of the carriage. An inclined portion extending obliquely upward in the ship width direction and the front-rear direction, and a horizontal portion extending horizontally following the inclined portion,
The thruster is attached to the horizontal portion, each thruster penetrates the horizontal portion downward, and the lower end of the thruster is located higher than the ship bottom.

  According to a second aspect of the present invention, in the first aspect, the output control means outputs the output of each thruster so that the base boat is positioned on the base boat towing line based on positioning information by a GPS (satellite navigation device). It is characterized by being configured to control.

  According to a third aspect of the present invention, in the first or second aspect, the output control means is configured to hold the base ship on a base ship towing line by controlling the output of each thruster. It is characterized by that.

  According to a fourth aspect of the present invention, in any one of the first to third aspects, a maintenance opening that is opened and closed by a hatch is formed in a portion facing each thruster of the deck of the carriage.

  According to the first aspect of the present invention, a thruster is disposed on the trolley, and the output of the thruster is controlled so that the trolley is positioned on the maritime trolley towing line corresponding to the target tubular body laying line. As a result, even if the trolley swings due to tide flow or shear waves, it can be returned to the trolley towing line with its own thrust, and the trolley can be stably placed on the trolley towing line. Can be positioned. As a result, the tubular body can be laid out along the target tubular body laying line with high accuracy, and in particular, the laying accuracy when performing the zigzag tubular body laying for avoiding obstacles such as the above-mentioned seabed rocks can be improved. it can.

In addition, since an accommodating part having an upper stage is formed on the bottom of the trolley, and the thruster is disposed in the accommodating part so that the lower end of the thruster is located higher than the bottom of the ship, the thruster is exposed downward from the bottom of the ship. No, it can prevent the thrusters from hitting the rocks on the seabed and damaging them.

In addition, since the accommodating portion is composed of an inclined portion inclined obliquely from the bottom of the ship and a horizontal portion extending horizontally following the inclined portion, and a thruster is attached to the horizontal portion, the water flow from the thruster is directed toward the bottom of the ship. It will flow smoothly, and the loss of thrust due to the formation of the accommodating portion on the ship bottom can be suppressed.

In the invention of claim 2 , since the absolute position of the trolley is obtained based on the positioning information by GPS, the trolley can be accurately positioned on the trolley towing line, and the laying accuracy of the submarine tubular body is improved. It can be further increased.

According to the invention of claim 3 , since the base ship is held at a fixed point on the barge towing line by controlling the output of each thruster of the barge, the barge is stabilized on the barge tow line and stopped. Therefore, it is possible to ensure the laying accuracy when performing the laying work such as landing of the tubular body in the stopped state. In this case, the anchoring work for holding the trolley at a fixed point is unnecessary, and the work man-hours and costs can be reduced.

In the invention of claim 4 , since the maintenance opening that is opened and closed by the hatch is formed in the portion facing the thruster of the deck, the maintenance work such as the thruster and the power unit can be easily performed from the deck by opening and closing the hatch.

  Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

FIGS. 1 to 3 are views for explaining a submarine cable laying system according to a first embodiment of the invention of claims 2 and 3. FIG. 1 is a perspective view of a submarine of the submarine cable laying system, and FIG. Side views of the trolley and FIGS. 3A and 3B are schematic views of the submarine cable laying system.

  In the figure, reference numeral 1 denotes a trolley of a submarine cable laying system. The carrier 1 is a laying work vessel that is towed by the tugboat 20 through a tow rope 21 and sunk in the sea while laying on the seabed while unsealing the submarine cable 2 mounted on the carrier 1. Although not illustrated, the submarine cable 2 has a structure in which, for example, a plurality of power transmission lines and optical fiber units are covered with an exterior member with a buffer member interposed therebetween.

  The hull 1a of the carriage 1 is, for example, about 90m long x 30m wide x 6m deep, and the submarine cable 2 is held in a wound state at the approximate center of the deck 1c of the hull 1a. A cable coil 3 is mounted, and a shooter 4 for sending the submarine cable 2 into the sea is disposed at the stern. The hull mountable length of the submarine cable 2 is, for example, about 50 km.

  Above the cable coil 3 of the deck 1c of the hull 1a, a gate-shaped erection base 5 is erected, and the erection base 5 is continuously connected to the shooter 4 while unsealing the submarine cable 2 from the cable coil 3. A cable path line 6 to be conveyed is arranged. Between the cable pass line 6 and the shooter 4, a main brake device 7 and an auxiliary brake device 8 that regulate the conveyance speed of the submarine cable 2 are arranged in series. Reference numeral 9 is a residence building for workers, and 10 and 11 are a control room and an operation room, respectively.

  In addition, a cable burying machine 22 is sunk in the seabed via a traction / power control cable 23 that is driven and controlled by the trolley 1. The cable burying machine 22 embeds the submarine cable 2 along a target cable laying line L ′ set on the seabed.

  The submarine cable laying system according to the present embodiment includes six thrusters 13 as thrust generating means for generating a thrust for stabilizing the position of the hull 1a with respect to tide flow and transverse waves, and the target cable laying line L ′. And a controller 12 as output control means for controlling the output of each thruster 13 so that the trolley 1 is always located on the trolley towing line L assumed on the sea.

  A display device 17 is connected to the controller 12, and the display device 17 displays a charter towing line L, a towed trajectory of the carriage 1 and a current position together with a chart. The controller 12 and the display device 17 are installed in the control room 10.

  Three thrusters 13 are arranged on the left and right sides of the bottom 1b of the hull 1a at predetermined intervals in the front-rear direction. Each thruster 13 is configured such that a screw is disposed in a casing and the direction of the screw can be rotated 360 ° in the horizontal plane together with the casing, whereby the thrust generation direction of each thruster 13 is 360 ° in the horizontal plane. It is possible to change freely in the range.

  The thrusters 13 are independently driven to rotate via a transmission 15 by a diesel engine 14 disposed in the hull 1a. A plurality of generators 14a for supplying power to a drive motor or the like for changing the thrust generation direction of the thruster 13 is mounted in the hull 1a.

  The controller 12 controls the thrust direction of the thruster 13, the rotational force of the screw, and the like so that the carriage 1 is positioned on the carriage ship towing line L based on positioning information by GPS (satellite navigation device). It is configured. The controller 12 is configured to stop and hold the barge 1 on the barge towing line L by controlling the thrust and direction of each thruster 13.

  Specifically, radio waves 18 from a plurality of artificial satellites 19 are received by the GPS antenna 16 installed on the gantry 5, and the absolute position (current position) of the carriage 1 is determined from the received radio waves 18. Desired. Then, the deviation of the absolute position of the carriage 1 with respect to the carriage towing line L is obtained, and the hull position correction amount is calculated based on this deviation, and the thrust and direction of each thruster 13 are controlled so as to obtain the correction amount. Is done.

  Further, as shown in FIG. 3 (b), when the cable burying machine 22 is shifted by Δt with respect to the target cable laying line L ′ due to the trolley 1 being caused to flow by the external force F such as a transverse wave and a transverse wind, The shift amount Δt is fed back to the controller 12, and the thrust and direction of each thruster 13 are corrected according to the shift amount Δt.

  As described above, according to the present embodiment, three thrusters 13 are arranged on the left and right sides of the bottom 1b of the carriage 1, respectively, and a maritime trolley towing assumed to correspond to the target cable laying line L '. Since the controller 12 for controlling the output of each thruster 13 is provided so that the barge 1 is positioned on the line L, even if the barge 1 is swung in the width direction due to a tide flow or a transverse wave, the The ship's own thrust can be used to return it to the barge tow line L, and the barge 1 can be stably positioned on the barge tow line L. As a result, the submarine cable 2 can be accurately laid along the target cable laying line L ′. As a result, it is possible to increase the laying accuracy when laying a zigzag cable to avoid obstacles such as bedrock on the seabed.

  In the present embodiment, since the absolute position of the carriage 1 is obtained using the radio waves 18 from the plurality of artificial satellites 19, the carriage 1 is towed while being accurately positioned on the carriage vessel towing line L. And the laying accuracy of the submarine cable 2 can be further increased.

  In this embodiment, the output of each thruster 13 of the barge 1 is controlled so that the barge 1 is held at a fixed point on the barge towing line L. Can be stabilized and the installation accuracy can be ensured when performing installation work such as cable landing in the stopped state. Since the throwing work is unnecessary, the man-hours and costs can be reduced accordingly.

  In the above embodiment, the laying of the submarine cable has been described. However, the present invention can be applied to any flexible tubular body laid on the seabed such as a water pipe or an oil pipe.

  Furthermore, the present invention can also be used when a structure is built on the sea floor by holding the carriage at a predetermined position.

4 to 6 are views for explaining a submarine cable laying system according to a second embodiment of the inventions of claims 1 and 4 . In the figure, the same reference numerals as those in FIGS. 1 and 2 denote the same or corresponding parts.

  In the present embodiment, the accommodating portions 1d are formed so as to be stepped upward at each corner portion of the bottom 1b of the carriage 1, and the thrusters 13 are disposed in the accommodating portions 1d.

  Each of the accommodating portions 1d includes an inclined portion 1e inclined obliquely upward from the ship bottom 1b toward the bow and stern, and a horizontal portion 1f extending horizontally following the inclined portion 1e. A thruster 13 is attached to 1e.

  Each thruster 13 is disposed such that the lower end thereof is positioned slightly higher than the outer bottom surface a of the ship bottom 1b. Thereby, the jet from each thruster 13 will flow smoothly to the ship bottom 1b side along the inclined part 1e.

  A maintenance opening 1g is formed in a portion of the deck 1c of the hull 1a facing the thrusters 13. The maintenance opening 1g is provided with a hatch 25 that opens and closes the opening 1g.

  According to the present embodiment, the accommodating portion 1d is formed on the bottom 1b of the carriage 1 so as to be stepped upward, and the thruster 13 is formed in the accommodating portion 1d so that the lower end thereof is higher than the outer bottom surface a of the bottom 1d. Since they are arranged so as to be positioned, each thruster 13 is not exposed downward from the ship bottom 1b, and it is possible to prevent the thruster 13 from hitting and damaging the rock on the seabed during navigation.

  Further, since the accommodating portion 1d is formed at each corner portion of the ship bottom 1b, the hull position can be stabilized by the minimum four thrusters 13. Each accommodating portion 1d is composed of an inclined portion 1e inclined from the bottom 1b toward the bow and stern, and a horizontal portion 1f extending horizontally following the inclined portion 1e, and a thruster 13 is attached to the horizontal portion 1f. Therefore, the water flow from the thruster 13 smoothly flows toward the bottom of the ship, and the loss of thrust due to the formation of the accommodating portion 1d on the ship bottom 1b can be suppressed.

  In the present embodiment, since the maintenance opening 1g that is opened and closed by the hatch 25 is formed in the portion of the deck 1c of the hull 1a that faces each thruster 13, by opening and closing the hatch 25, the diesel engine 14, the transmission 15, Maintenance work of the thruster 13 and the like can be easily performed.

1 is a perspective view of a trolley of a submarine cable laying system according to a first embodiment of the present invention. It is a side view of the said trolley. It is a schematic diagram of the said submarine cable laying system. It is a side view of the trolley of the submarine cable laying system by a 2nd embodiment of the present invention. It is a top view of the bow part of the said trolley. It is a cross-sectional front view of the bow part of the said trolley.

Explanation of symbols

1 carrier 1a hull 1b ship bottom 1c deck 1d receiving part 1e inclined part 1f horizontal part 1g maintenance opening 2 submarine cable (flexible tubular body)
12 Controller (Output control means)
13 Thruster 14 Engine (drive unit)
25 Hatch L

Claims (4)

The above-mentioned table is placed on the trolley towing line assumed on the sea corresponding to the thruster to stabilize the hull position and the target tubular body laying line on the sea floor. An output control means for controlling the output of the thruster so that the ship is positioned, and a flexible tubular body mounted on the trolley in a wound state is submerged in the sea and laid on the sea floor. In body laying system,
The thruster is disposed in a housing portion formed so as to be stepped upward at four corner portions located on the left and right sides of the bow side and the stern side of the bottom of the carriage. An inclined portion extending obliquely upward in the ship width direction and the front-rear direction, and a horizontal portion extending horizontally following the inclined portion,
The thruster is attached to the horizontal part, each thruster penetrates the horizontal part downward, and the lower end of the thruster is positioned higher than the ship bottom. system.   2. The output control means according to claim 1, wherein the output control means is configured to control the output of each thruster so that the barge is positioned on a barge towing line based on positioning information by a GPS (satellite navigation device). A submarine tubular body laying system characterized by comprising:   3. The submarine tubular according to claim 1, wherein the output control means is configured to hold the base ship at a fixed point on the base ship towing line by controlling the output of each thruster. Body laying system.   4. The submarine tubular body laying system according to claim 1, wherein a maintenance opening that is opened and closed by a hatch is formed in a portion facing each thruster of the deck of the carriage.

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