CN117526150A - Submarine cable salvaging and maintaining method - Google Patents

Abstract

The invention relates to the field of submarine cable maintenance, in particular to a submarine cable salvage maintenance method which is mainly used for submarine cable maintenance, adopts four search construction ships for maintenance, can respectively and simultaneously carry out preparation work, has definite division, and has the advantages of annular procedures, accurate positioning, maintenance accuracy improvement, maintenance time shortening greatly, maintenance efficiency improvement and maintenance suspension or even failure prevention caused by climate change; the technical problem of sea cable maintenance inefficiency is solved.

Description

Submarine cable salvaging and maintaining method

Technical Field

The invention relates to the field of submarine cable maintenance, in particular to a submarine cable salvaging and maintaining method.

Background

Submarine cables are wires wrapped by insulating materials and laid on the sea and under rivers for telecommunication transmission. Modern submarine cables use optical fibers as the material for transmitting telephone and internet signals. The first submarine cable in the world was laid between uk and france 1850. The first submarine cable in China was completed in 1988, and the first submarine cable is between the Fuzhou Chuanshi island and the Taiwan Shanghai tail (fresh water) in China, the second submarine cable is led to Penghu from Tainan in China, and the first submarine cable is in 53 seas. When the submarine cable fails, the submarine cable needs to be operated under water, and maintenance is very inconvenient; when maintaining, need predict weather, open a ship, dive, salvage, sea cable is sunk, sea cable handing-over, test a series of operations such as detect, not only work load is huge, and the degree of difficulty is big moreover, and every link is very important, if one of them link appears the deviation, probably leads to careful planning's maintenance work to end with the failure, need to reselect a time again and maintain. The existing submarine cable is maintained for a long time and low in maintenance efficiency.

Disclosure of Invention

Therefore, the invention provides a submarine cable salvage maintenance method aiming at the problems. The technical problem of low submarine cable maintenance efficiency is solved.

In order to achieve the above purpose, the present invention adopts the following technical scheme:

a submarine cable salvaging and maintaining method comprises the following steps:

(1) Salvaging and laying a new submarine cable:

according to a new submarine cable sinking layout and coordinates, a first construction ship reaches the vicinity of a submarine cable end, four anchoring positions are anchored, a diver enters water to find a new submarine cable end, a traction steel cable is connected, a winch at the stern is utilized for reeling, a ship is moved along the submarine cable direction, the angle of the submarine cable is kept at 5-10 degrees, after the submarine cable enters a cable laying machine, the winch continues reeling until the submarine cable enters an electric turntable, a cable coiling is continued to be recovered until the other end of the new submarine cable is completely discharged, after a cable head is left on a trolley, the submarine cable water inlet condition is checked and treated, and an optical fiber test, an insulation test and a lead seal are performed; when the new submarine cable is salvaged, the phase of the rear end head of the submarine cable needs to be combined before cutting, and the direction of the new submarine cable is prepared in advance;

the ship comprises a first construction ship, wherein a starboard side or a port side edge of the first construction ship is provided with a diving suspension cage, both sides of a deck of the first ship are provided with fences, the first construction ship is provided with a cable distributing machine and at least one electric turntable, and the deck of the first ship is provided with at least one arc plate to control the minimum bending radius of a submarine cable and prevent the submarine cable from being excessively bent to be damaged;

(2) Laying a new submarine cable:

the first construction ship is anchored into the point, and when anchored, a floating ball is tied on a steel wire crossing the sea cable;

(3) Throwing in a buried plow:

after the submarine cable is put into the abdomen of the buried plow, closing the door plate, slowly hanging the buried plow into water by adopting a crane, placing the buried plow on the seabed surface, and slowly placing the buried plow on the seabed;

(4) Sea cable detection cuts off and dehumidifies lead sealing:

a fourth construction ship carries a diver into a construction site, the diver cuts off the submarine cable near the fault point under water, and after cutting is completed, the submarine cable ends at two sides are immediately recovered to a deck; after the submarine cable end is recovered to the deck, firstly performing visual inspection, and cutting if the water inflow in the submarine cable is serious until no obvious water inflow condition exists; then checking the water-blocking tape in the submarine cable, and continuing to cut off if the water-blocking tape expands until the water-blocking tape is intact;

after the sea cable is dehumidified, carrying out integrity retest on the sea cable at two sides, judging whether the sea cable is good in insulation performance through insulation test, judging whether the sea cable is good in optical fiber through optical fiber detection, carrying out sea cable full-length data acquisition and abnormal waveform judgment through a low-voltage pulse method, detecting the sea cable ends at two sides according to the mode, if one of the sea cable ends is detected to be unqualified, continuing to recover the sea cable, cutting off the sea cable, detecting the sea cable until the sea cable is detected to be qualified, and carrying out lead sealing treatment on a notch after the sea cable is qualified so as to prevent water vapor from entering the sea cable; after lead sealing, the submarine cable ends on two sides are firstly connected with a steel wire rope through shackles, then are connected with the steel wire rope through a lifting rope, the other ends are bound and float on the sea surface through buoys, the submarine cable ends are placed on the sea bed, and beacon recording is carried out on the positions of the submarine cable ends;

(5) Two platform ship access points: inserting legs at the inlet points of the second construction ship and the third construction ship, wherein the elevation of the mud surface is h1, the elevation of the bottom of the mud layer is h2, the length h of the pile leg is more than or equal to h2+h0, and h0 is the height of an air gap;

the second construction ship and the third construction ship are provided with a ship positioning system, a lifting hook system and pile legs;

(6) Salvaging and fixing submarine cable ends:

the fourth construction ship pulls the new submarine cable end and the old submarine cable end to the deck through the fishing buoy respectively, then moves to the side of the second construction ship and the side of the third construction ship, the second construction ship and the third construction ship hoist the submarine cable end to the deck of the second construction ship from the arc plates at two sides through the crane, the guide wheels are arranged at proper positions on the deck, the fishing and the traction of the submarine cable are carried out by using the winch on the deck and the auxiliary of the deck crane, the monitoring is implemented in the traction process, and smooth and non-bending submarine cable fishing is ensured;

firstly, checking the water inflow condition of two ends of a submarine cable, cutting off the submarine cable which is dragged by external force when the two ends of the submarine cable are in water inflow and salvaged (each end is cut off by about 5-10 m), then pulling each submarine cable by about 25m, conveying the submarine cable end to a submarine cable joint chamber, ensuring that the two submarine cables are parallel and cross by about 7m, fixing the submarine cable on a platform deck, ensuring that the submarine cable is not displaced on the platform, and fixing the submarine cable in a double fixing mode, namely fixing the submarine cable on the edge of a ship and the outside of an access joint chamber, wherein the submarine cable buffering space can be reserved in the middle, and simultaneously, 6-8 brackets for raising the submarine cable by 0.5m are arranged on the platform ship, and fixing the submarine cable on a manufacturing platform;

(7) And (3) manufacturing a hard joint:

before optical fiber fusion, the optical fibers in the submarine cable at the two ends for manufacturing the hard joint are subjected to one-time on-off attenuation detection, after the optical fibers are fused, the optical cable splice box is placed in the shell and hung into the sea, and when the hard joint is buried, the hard joint and the central axis of the submarine cable are ensured to be in the same straight line; after the submarine cable is fished onto the operation platform, performing optical fiber OTDR inspection, primarily judging whether the submarine cable is intact by using attenuation indexes and lengths of the submarine cable tested by the optical fiber OTDR, and performing insulation performance test of the submarine cable;

(8) Armor stripping:

when the submarine cable is in place, the submarine cable needs to be staggered for 7 meters due to the fact that the optical fibers are connected, the armor of about 7 meters is stripped backwards from the middle position of the work shed, each 2 meters of stripped armor length is reserved, the submarine cable at the stripping end is stripped, the reserved staggered length of 1.5 meters is reserved, and then the rest part is cut off;

(9) Optical fiber fusion and mechanical protection:

after the intermediate joint is manufactured, optical cable connection and optical cable joint box installation are carried out firstly (on-shore on-line OTDR test is carried out); on the premise of ensuring quality and safety, the installation of the protective shell is synchronously carried out; after the protective shell is installed, the polyurethane glue is poured into the glue pouring holes;

(10) Sinking the submarine cable joint: after the submarine cable hard joint passes the completion test, removing the temporary joint manufacturing room, emptying the deck, and preparing a hanging beam, a hanging strip and a shackle;

binding the sea cables with steel wire ropes of about 30 meters at two ends of the joint on the sea cable, marking each 5 meters with paint with two different colors, taking care of a special person, then hanging the joint and the bending limiter by using a multi-point hanging tool by using a crane, lying down the arm in a vertical routing direction at the speed of 2-3 meters/min, slowly paying out the sea cable after the steel wire ropes at the left side and the right side are stressed, tightly preventing the sea cable from freely sliding into the sea from a deck so as not to impact the joint and the sea cable, slowly hanging the joint and the sea cable into water until the sea cable is smoothly placed on the sea bed, and keeping the steel wire outwards slightly all the time until the nylon rope and the steel wire are not stressed, and sinking the sea cable in the vertical routing direction at the top end of an omega shape;

after the hard joint is planted, a diver firstly observes whether the hard joint is placed smoothly on the seabed or not and whether a submarine cable is bent or not, and simultaneously performs exploring and USBL beacon dotting on the submarine cable track near the end head, then removes a lifting appliance and a rope, and recovers an upper deck; the distance between the two groups of hard joints is more than 120 m, so that the two groups of hard joints are prevented from interfering with each other for construction, and the subsequent maintenance of the hard joints is ensured to have enough allowance;

(11) Sea cable test detection and protection:

after the construction of the two joints is completed, carrying out sea cable alternating current withstand voltage test and optical fiber test, resetting the interior of the offshore booster station and the sea cable terminal after the test and the test are qualified, finally, selecting a machine to flush and bury the hard joint and the sea cable on the exposed seabed, wherein the flush and burying depth is not less than 2 meters, and recording the routing coordinates and the burying depth of the sea cable and the joint.

Further:

the distance L between the upper sea cable position of the arc plate and the end of the original sea cable is (L-L1) 2 is more than or equal to (h0+h3+h4) +L2, L1 is the sea cable deck length, L2 is the linear distance from the original sea cable, h3 is the highest tide depth, and h4 is the model depth.

The distance L0 between the upper sea cable position of the arc plate and the end of the new sea cable is (L0-L1) 2 is not less than (h0+h3+h4) +L3, L1 is the length of the upper sea cable deck, L3 is the linear distance from the upper sea cable, h3 is the highest tide depth, and h4 is the model depth.

The edge of the diving cage is required to be flush with the outermost board of the ship body.

The fence is of a steel structure with the height of 2 m.

Sea cable fixing bollards are welded on two sides of a sea cable channel behind the arc plates and are used for fixing sea cables.

The hard joint comprises a 220kV integral prefabricated insulating part middle joint, a joint protection shell and bending limiters, wherein a group of bending limiters are arranged at two ends of each joint, the diameter of the hard joint after the assembly is completed is about 1m, the total length of the hard joint is about 27m, and the two ends of the hard joint are respectively provided with 10m bending limiters.

The hanging beam is 12 m, the bearing is more than 20T, the bearing is more than 10T, and the bearing is more than 10T; the top of the hanging beam is provided with two first hanging points, and the bottom of the hanging beam is provided with eight second hanging points.

The buried plow is thrown and operated according to the following procedures:

(1) a plow is arranged to lift and put in the middle of the trolley;

(2) the submarine cable is put into the abdomen of the buried plow, the door plate is closed, and the moving ship controls the submarine cable water inlet angle to be 45-60 degrees, so that the bending radius of the submarine cable when the buried plow is put in is ensured;

(3) lifting the buried plow, and moving the trolley to the bow to allow the trolley to go out of the buried plow and enter the water space;

(4) starting a water pump, and checking the pressure of the water pump;

(5) moving the ship and simultaneously releasing the submarine cable, and slowly placing the buried plow on the seabed;

(6) starting a buried depth monitoring system;

(7) the worker and the boat are anchored, and traction and burying operation are started.

The intermediate joint comprises a plurality of small joints which are arranged in a staggered way up and down.

By adopting the technical scheme, the invention has the beneficial effects that:

according to the invention, four search construction vessels are adopted for overhauling, a first construction vessel is adopted for salvaging and cutting off lead sealing of a new sea cable, a second construction vessel and a third construction vessel of a self-elevating landing leg platform vessel are adopted as main maintenance vessels, two sea cable connectors are mainly used for simultaneous manufacture and sinking, a fourth construction vessel is an auxiliary maintenance vessel, mainly working such as sea cable cutting-off and sea cable salvaging can be respectively and simultaneously carried out for preparation work, division work is clear, working procedures are looped, accurate positioning can be realized, overhauling precision is improved, maintenance time is greatly shortened, maintenance efficiency is improved, and maintenance suspension and even failure caused by climate change are prevented; (1) When the new sea cable is salvaged, the angle is kept at 5-10 degrees, so that the new sea cable is prevented from being damaged due to large bending; (2) The steel wires of the submarine cable cross anchors are tied with floating balls so as to avoid friction of the submarine cables, and the anchor is thrown away from the laid submarine cable routes; (3) buried plow is used for shallow sea bottom ditching. It can be towed on the sea floor, plow a channel with the depth of 0.7-1 meter, and be used for burying submarine cables; (4) When the fourth construction ship cuts off, detects and maintains the old sea cable, the second construction ship and the third construction ship can carry out position adjustment according to the cutting-off length of the old sea cable; (5) After the positions of the second construction ship and the third construction ship are determined, the pile legs are inserted into mud for fixing, the length of the pile legs is not smaller than the elevation of the bottom of the silt layer plus the height of an air gap, and the fixing is more stable, so that the quick maintenance of maintenance personnel is facilitated; (6) Moving two ends of the old submarine cable and the new submarine cable to a second construction ship and a third construction ship respectively through a fourth construction ship, and respectively performing joint and detection on the second construction ship and the third construction ship; (7) Detecting the salvaged old submarine cable and the salvaged new submarine cable, and ensuring that no fault occurs after connection; (8) The submarine cables need to be staggered for 7 meters, and the staggered length of 1.5 meters is reserved, so that the submarine cable is prevented from being insufficient in length, and the smooth maintenance is improved; when the submarine cable connector is sunk, the hanging beam, the hanging strip and the shackle are adopted, so that the submarine cable is sunk into the seabed in the direction of the vertical route of the top end of the omega shape, the connector and the submarine cable are prevented from forming impact, the submarine cable is beneficial to being laid flatly, and the submarine cable is prevented from being bent and damaged.

Further, the sea cable rush-repair by adopting the landing leg ship has the advantages of safety, high efficiency, strong adaptability, low cost and the like:

(1) The safety is improved: the landing leg ship can provide a stable platform, so that the rush repair work is safer. When the landing leg ship works on the sea, the landing leg ship can be kept balanced, and the shaking of the ship body caused by sea waves and sea winds is reduced, so that the risks of operators and equipment are reduced;

(2) Efficiency is improved: the landing leg ship can operate on the sea for a long time without returning to the shore for replenishment and maintenance. Meanwhile, various maintenance equipment and tools can be carried on the landing leg ship, and the rush repair work can be rapidly carried out, so that the operation efficiency is improved;

(3) The method is suitable for complex marine environments: submarine cable faults typically occur on the ocean floor, requiring emergency repair in a marine environment. The landing leg ship can adapt to different marine environments and weather conditions, can operate under the condition of large sea waves, and improves the success rate of rush repair;

(4) The cost is reduced: the supporting leg ship is adopted to carry out sea cable rush repair, so that the transportation cost of personnel and equipment can be reduced, and meanwhile, the rush repair time and the labor cost can be reduced. The landing leg ship is adopted to carry out sea cable rush-repair, so that the rush-repair time can be reduced under complex sea conditions, the generated energy loss caused by sea cable damage is reduced, and the operation efficiency is improved.

Further, the distance L between the sea cable position and the original sea cable end is calculated through the formula (L-L1) 2 is more than or equal to (h0+h3+h4) +L2, the distance L0 between the sea cable position on the arc plate and the new sea cable end is calculated through the formula (L0-L1) 2 is more than or equal to (h0+h3+h4) +L3, the determination of the optimal positions of two platform ships is facilitated, the sea cable after maintenance is prevented from being overlong or too short, the position of the two platform ships is prevented from being deviated, the sea cable can be horizontally put down when being sunk, the quality of the sea cable after maintenance is improved, and the maintenance efficiency of the sea cable is improved.

Furthermore, the edge of the diving suspension cage is required to be flush with the outermost board of the ship body, so that the suspension cage is ensured not to collide with the ship body when being put down.

Further, set up the crooked limiter in the hard joint, can increase the intensity of connecting back submarine cable, when preventing submarine cable subsidence, hard joint department takes place wearing and tearing even fracture.

Furthermore, the bottom of the hanging beam is provided with eight second hanging points, which is beneficial to horizontal hanging of the submarine cable.

Further, the water inlet angle of the submarine cable is controlled to be between 45 and 60 degrees, so that the bending radius of the submarine cable when the plow is buried is ensured, and the submarine cable is prevented from being damaged.

Drawings

FIG. 1 is a schematic view of the construction of a second and third construction vessel at the point of entry for anchoring;

FIG. 2 is a schematic view of the structure of a second construction vessel sea cable towing upper deck;

FIG. 3 is a schematic illustration of the structure of a new sea cable and an old sea cable interlaced;

FIG. 4 is a schematic illustration of armor stripping of new and old submarine cables;

FIG. 5 is a schematic view of the structure of an intermediate joint;

FIG. 6 is a simplified side view of an intermediate joint;

FIG. 7 is a schematic structural view of the joint protection housing;

FIG. 8 is a schematic view of the submarine cable after repair;

FIG. 9 is a schematic view of a construction of a hanging beam;

FIG. 10 is a schematic view of a structure in which a hoist beam lifts a sea cable;

FIG. 11 is a schematic view of a submarine cable joint fabrication chamber;

fig. 12 is a schematic view of the construction of the scaffold inside the splice fabrication chamber.

Detailed Description

The invention will now be further described with reference to the drawings and detailed description.

Referring to fig. 1 to 12, the present embodiment provides a submarine cable salvage maintenance method, which includes the following steps:

(1) Salvaging and laying a new submarine cable:

according to a new submarine cable sinking layout and coordinates, a first construction ship reaches the vicinity of a submarine cable end, four anchoring positions are anchored, a diver enters water to find a new submarine cable end, a traction steel cable is connected, a winch at the stern is utilized for reeling, a ship is moved along the submarine cable direction, the angle of the submarine cable is kept at 5-10 degrees, after the submarine cable enters a cable laying machine, the winch continues reeling until the submarine cable enters an electric turntable, a cable coiling is continued to be recovered until the other end of the new submarine cable is completely discharged, after a cable head is left on a trolley, the submarine cable water inlet condition is checked and treated, and an optical fiber test, an insulation test and a lead seal are performed; when the new submarine cable is salvaged, the phase of the rear end head of the submarine cable needs to be combined before cutting, and the direction of the new submarine cable is prepared in advance;

the ship is characterized in that a diving suspension cage is arranged on the starboard or port side edge of the first construction ship, the edge of the diving suspension cage is required to be flush with the outermost board of the ship body, two sides of a deck of the first ship body are provided with fences, and the fences are of steel structures with the height of 2 m. The first construction ship is provided with a cable laying machine and at least one electric turntable, at least one arc plate is arranged at the deck of the first ship body, sea cable fixing bollards are welded at two sides of a sea cable channel behind the arc plate and used for fixing sea cables so as to control the minimum bending radius of the sea cables and prevent the sea cables from being excessively bent to be damaged;

(2) Laying a new submarine cable:

the first construction ship is anchored into the point, and when anchored, a floating ball is tied on a steel wire crossing the sea cable;

(3) Throwing in a buried plow:

after the submarine cable is put into the abdomen of the buried plow, the door plate is closed, the buried plow is slowly hung into water by adopting a crane and is placed on the seabed surface, and the buried plow is put in to operate according to the following procedures:

(1) a plow is arranged to lift and put in the middle of the trolley;

(2) the submarine cable is put into the abdomen of the buried plow, the door plate is closed, and the moving ship controls the submarine cable water inlet angle to be 45-60 degrees, so that the bending radius of the submarine cable when the buried plow is put in is ensured;

(3) lifting the buried plow, and moving the trolley to the bow to allow the trolley to go out of the buried plow and enter the water space;

(4) starting a water pump, and checking the pressure of the water pump;

(5) moving the ship and simultaneously releasing the submarine cable, and slowly placing the buried plow on the seabed;

(6) starting a buried depth monitoring system;

(7) the worker and the boat are anchored, and traction and burying operation are started.

(4) Sea cable detection cuts off and dehumidifies lead sealing:

a fourth construction ship carries a diver into a construction site, the diver cuts off the submarine cable near the fault point under water, and after cutting is completed, the submarine cable ends at two sides are immediately recovered to a deck; after the submarine cable end is recovered to the deck, firstly performing visual inspection, and cutting if the water inflow in the submarine cable is serious until no obvious water inflow condition exists; and then checking the water-blocking tape in the submarine cable, and continuing to cut off if the water-blocking tape expands until the water-blocking tape is intact.

After the sea cable is dehumidified, carrying out integrity retest on the sea cable at two sides, judging whether the sea cable is good in insulation performance through insulation test, judging whether the sea cable is good in optical fiber through optical fiber detection, carrying out sea cable full-length data acquisition and abnormal waveform judgment through a low-voltage pulse method, detecting the sea cable ends at two sides according to the mode, if one of the sea cable ends is detected to be unqualified, continuing to recover the sea cable, cutting off the sea cable, detecting the sea cable until the sea cable is detected to be qualified, and carrying out lead sealing treatment on a notch after the sea cable is qualified so as to prevent water vapor from entering the sea cable; after lead sealing, the submarine cable ends on two sides are connected with a steel wire rope through shackles, then are connected with the steel wire rope through a lifting rope, the other ends are bound and float on the sea surface through buoys, the submarine cable ends are placed on the sea bed, and beacon recording is carried out on the positions of the submarine cable ends.

(5) Two platform ship access points: the second construction ship and the third construction ship are inserted into the point, the elevation of the mud surface is h1, the elevation of the bottom of the mud layer is h2, the length h of the pile leg is greater than or equal to h2+h0, and h0 is the height of the air gap.

And the second construction ship and the third construction ship are provided with a ship positioning system, a lifting hook system and pile legs. As shown in fig. 1 and 2, the second and third construction vessels 1 and 2 are located at sea, the point a is a sea cable failure point, and the old sea cable 3 and the new sea cable 4 are spliced and detected in the splice manufacturing room 5.

The distance L between the upper sea cable position of the arc plate and the end of the original sea cable is (L-L1) 2 is more than or equal to (h0+h3+h4) +L2, L1 is the sea cable deck length, L2 is the linear distance from the original sea cable, h3 is the highest tide depth, and h4 is the profile depth; the distance L0 between the upper sea cable position of the arc plate and the end of the new sea cable is (L0-L1) 2 is not less than (h0+h3+h4) +L3, L1 is the length of the upper sea cable deck, L3 is the linear distance from the upper sea cable, h3 is the highest tide depth, and h4 is the model depth.

As shown in fig. 11 and 12, the joint making room 8 is constructed by using a tent and scaffold structure, and is constructed by using tarpaulin to resemble a simple house type joint making room and has a certain wind resistance and water resistance. According to the arrangement mode of the protective shell and the internal middle joint, in order to ensure the installation, the length, width and height of the inner part of the joint manufacturing chamber are at least 8m 4m 2m, 1 scaffold 81 is arranged in the joint manufacturing chamber by using a steel pipe and a clamp, and the scaffold is placed right above a joint installation area so as to use a hoist to hoist/move a submarine cable/joint in the installation process; scaffold dimensions: the length is 6m, the height is 2m, the width is 4m, the upper cross arm of the scaffold can bear the falling force of 250kg, the joint manufacturing room is used as an installation clean room, the floor cleaning is required, a dust collector is required to clean the interior of the clean room before installation, no dust is ensured, (a layer of floor leather is paved on the floor inside the joint manufacturing room, so that the dust on the floor is avoided from being generated again due to walking of people to a great extent), 2-3 windows 82 are arranged on each of the long sides of the two sides of the window of the joint manufacturing room, so that the interior of the joint manufacturing room is transparent, 6-9 fluorescent lamps (or at least 5 construction illuminating lamps with the power of 150-200 watts and a plurality of spare bulbs) are arranged at the top of the joint manufacturing room, so that illumination is realized; dampproofing, prevent wind, dustproof, constant temperature: an air conditioner, a purifier, a dehumidifier and the like are required to be installed, so that the environmental indexes of the joint chamber meet the following requirements: the temperature is 10-35 ℃ and the relative humidity is less than 80 percent. (set up the hygrothermograph and detect), connect the indoor top installation radial girder steel of preparation, can be used to hang calabash and suspender (load 3 t) to conveniently erect sea cable, remove accessory etc. indoor power supply: 1 single 220V power line is needed for the middle joint construction (5 kW).

(6) Salvaging and fixing submarine cable ends:

after the fourth construction ship pulls the new submarine cable end and the old submarine cable end to the deck through the fishing buoy respectively, the new submarine cable end and the old submarine cable end are moved to the side of the second construction ship and the side of the third construction ship, the second construction ship and the third construction ship hoist the submarine cable end from the arc plates on two sides to the deck of the second construction ship and the third construction ship through the crane, the guide wheels are arranged at proper positions on the deck, the marine cable is fished and towed by using the winch on the deck and the auxiliary crane on the deck, and the towing process is monitored, so that smooth and non-bending submarine cable is ensured when the submarine cable is fished.

Firstly, checking the water inflow condition of two ends of a submarine cable, cutting off the submarine cable which is dragged by external force when the two ends of the submarine cable are in water inflow and salvaged (each end is cut off by about 5-10 m), then pulling each submarine cable by about 25m, conveying the submarine cable ends to a submarine cable joint chamber, ensuring that the two submarine cables are parallel and intersected by about 7m, fixing the submarine cable on a platform deck, ensuring that the submarine cable is not displaced on the platform, and fixing the submarine cable by adopting a double fixing mode, namely fixing one outside a ship edge and an access joint chamber respectively, leaving a submarine cable buffering space in the middle, simultaneously providing 6-8 brackets for lifting the submarine cable by 0.5m on the platform ship, and fixing the submarine cable on a manufacturing platform.

(7) And (3) manufacturing a hard joint:

before optical fiber fusion, the optical fibers in the submarine cable at the two ends for manufacturing the hard joint are subjected to one-time on-off attenuation detection, after the optical fibers are fused, the optical cable splice box is placed in the shell and hung into the sea, and when the hard joint is buried, the hard joint and the central axis of the submarine cable are ensured to be in the same straight line; after the submarine cable is fished onto the operation platform, performing optical fiber OTDR inspection, primarily judging whether the submarine cable is intact by using attenuation indexes and lengths of the submarine cable tested by the optical fiber OTDR, and performing insulation performance test of the submarine cable; as shown in fig. 3 to 8, the hard joint 6 comprises a 220kV integral prefabricated insulating member middle joint 61, a joint protection housing 62 and bending limiters 63, a group of bending limiters 63 are respectively arranged at two ends of each joint, two glue filling holes 64 are formed in the joint protection housing 62, the diameter of the hard joint after the hard joint is assembled is about 1m, the total length is about 27m, the bending limiters are respectively arranged at the two ends of the hard joint, the middle joint comprises a plurality of small joints, and the small joints are arranged in an up-down staggered manner.

The outer diameter of the joint protection shell is 1m, the outer diameter of the bending limiter is 0.56m, and the outer diameter of the joint protection shell is not smaller than 0.8m, and the outer diameter of the bending limiter is not smaller than 0.5m. The structure can not be transitionally bent when the submarine cable is lifted and settled, so that the submarine cable is prevented from being damaged.

(8) Armor stripping:

as shown in fig. 3 to 8, when the submarine cable is in place, the submarine cable needs to be staggered for 7 meters due to the optical fiber connection, the armor is stripped back from the middle position of the work shed for about 7 meters, each end of the stripped armor length is reserved for 2 meters, and the submarine cable at the stripping end is stripped, reserved for staggered for 1.5 meters, and then the rest part is cut off.

(9) Optical fiber fusion and mechanical protection:

after the intermediate joint is manufactured, optical cable connection and optical cable joint box installation are carried out firstly (on-shore on-line OTDR test is carried out); on the premise of ensuring quality and safety, the installation of the protective shell is synchronously carried out; after the protective housing is installed, the glue-pouring holes 64 are filled with polyurethane glue (two-component glue, which requires stirring).

(10) Sinking the submarine cable joint: after the submarine cable hard joint passes the completion test, removing the temporary joint making room, emptying the deck, and preparing a hanging beam 7, a hanging strip 70 and a shackle as shown in fig. 8 to 10;

the hanging beam is 12 m, the bearing is more than 20T, the bearing is more than 10T, and the bearing is more than 10T; the top of the hanging beam is provided with two first hanging points 71, the center symmetry interval of the two first hanging points 71 is 6 meters, each can bear at least 20T, the bottom of the hanging beam is provided with eight second hanging points 72, the centers of the second hanging points 72 are symmetrical, the interval of the second hanging points at two ends is 2 meters, the interval of the other second hanging points is 1.5 meters, and each can bear at least 10T. The middle four second hanging points are connected with the joint protection shell, and other second hanging points positioned on two sides are connected with the bending limiter.

Binding the sea cables with steel wire ropes of about 30 meters at two ends of the joint on the sea cable, marking each 5 meters with paint with two different colors, taking care of a special person, then hanging the joint and the bending limiter by using a multi-point hanging tool by using a crane, lying down the arm in a vertical routing direction at the speed of 2-3 meters/min, slowly paying out the sea cable after the steel wire ropes at the left side and the right side are stressed, tightly preventing the sea cable from freely sliding into the sea from a deck so as not to impact the joint and the sea cable, slowly hanging the joint and the sea cable into water until the sea cable is smoothly placed on the sea bed, and keeping the steel wire outwards slightly all the time until the nylon rope and the steel wire are not stressed, and sinking the sea cable in the vertical routing direction at the top end of an omega shape;

after the hard joint is planted, a diver firstly observes whether the hard joint is placed smoothly on the seabed or not and whether a submarine cable is bent or not, and simultaneously performs exploring and USBL beacon dotting on the submarine cable track near the end head, then removes a lifting appliance and a rope, and recovers an upper deck; the distance between the two groups of hard joints is more than 120 m, so that the two groups of hard joints are prevented from interfering with each other for construction, and the subsequent maintenance of the hard joints is ensured to have enough allowance;

(11) Sea cable test detection and protection:

after the construction of the two joints is completed, carrying out sea cable alternating current withstand voltage test and optical fiber test, resetting the interior of the offshore booster station and the sea cable terminal after the test and the test are qualified, finally, selecting a machine to flush and bury the hard joint and the sea cable on the exposed seabed, wherein the flush and burying depth is not less than 2 meters, and recording the routing coordinates and the burying depth of the sea cable and the joint.

While the invention has been particularly shown and described with reference to a preferred embodiment, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.

Claims (10)

1. A submarine cable salvaging and maintaining method is characterized by comprising the following steps of: the method comprises the following steps:

(1) Salvaging a new submarine cable:

according to a new submarine cable sinking layout and coordinates, a first construction ship reaches the vicinity of a submarine cable end, four anchoring positions are anchored, a diver enters water to find a new submarine cable end, a traction steel cable is connected, a winch at the stern is utilized for reeling, a ship is moved along the submarine cable direction, the angle of the submarine cable is kept at 5-10 degrees, after the submarine cable enters a cable laying machine, the winch continues reeling until the submarine cable enters an electric turntable, a cable coiling is continued to be recovered until the other end of the new submarine cable is completely discharged, after a cable head is left on a trolley, the submarine cable water inlet condition is checked and treated, and an optical fiber test, an insulation test and a lead seal are performed; when the new submarine cable is salvaged, the phase of the rear end head of the submarine cable needs to be combined before cutting, and the direction of the new submarine cable is prepared in advance;

the ship comprises a first construction ship, wherein a starboard side or a port side edge of the first construction ship is provided with a diving suspension cage, both sides of a deck of the first ship are provided with fences, the first construction ship is provided with a cable distributing machine, at least one electric turntable and a winch, and the deck of the first ship is provided with at least one arc plate to control the minimum bending radius of a submarine cable and prevent the submarine cable from being excessively bent to be damaged;

(2) Laying a new submarine cable:

according to the position of the fault submarine cable scanned on the seabed, a first construction ship carries out new submarine cable laying operation according to the direction 5-30 m away from the original design route in the south, and a floating ball is tied on a steel wire crossing the new submarine cable when the first construction ship breaks down at an anchor point;

(3) Throwing in a buried plow:

after the submarine cable is put into the abdomen of the buried plow, closing the door plate, slowly hanging the buried plow into water by adopting a crane, placing the buried plow on the seabed surface, and slowly placing the buried plow on the seabed;

(4) Sea cable detection cuts off and dehumidifies lead sealing:

a fourth construction ship carries a diver into a construction site, the diver cuts off the submarine cable near the fault point under water, and after cutting is completed, the submarine cable ends at two sides are immediately recovered to a deck; after the submarine cable end is recovered to the deck, firstly performing visual inspection, and cutting if the water inflow in the submarine cable is serious until no obvious water inflow condition exists; then checking the water-blocking tape in the submarine cable, and continuing to cut off if the water-blocking tape expands until the water-blocking tape is intact;

after the sea cable is dehumidified, carrying out integrity retest on the sea cable at two sides, judging whether the sea cable is good in insulation performance through insulation test, judging whether the sea cable is good in optical fiber through optical fiber detection, carrying out sea cable full-length data acquisition and abnormal waveform judgment through a low-voltage pulse method, detecting the sea cable ends at two sides according to the mode, if one of the sea cable ends is detected to be unqualified, continuing to recover the sea cable, cutting off the sea cable, detecting the sea cable until the sea cable is detected to be qualified, and carrying out lead sealing treatment on a notch after the sea cable is qualified so as to prevent water vapor from entering the sea cable; after lead sealing, the submarine cable ends on two sides are firstly connected with a steel wire rope through shackles, then are connected with the steel wire rope through a lifting rope, the other ends are bound and float on the sea surface through buoys, the submarine cable ends are placed on the sea bed, and beacon recording is carried out on the positions of the submarine cable ends;

(5) Two platform ship access points: inserting legs at the inlet points of the second construction ship and the third construction ship, wherein the elevation of the mud surface is h1, the elevation of the bottom of the mud layer is h2, the length h of the pile leg is more than or equal to h2+h0, and h0 is the height of an air gap;

the second construction ship and the third construction ship are provided with a ship positioning system, a lifting hook system and pile legs;

(6) Salvaging and fixing submarine cable ends:

the fourth construction ship pulls the new submarine cable end and the old submarine cable end to the deck through the fishing buoy respectively, then moves to the side of the second construction ship and the side of the third construction ship, the second construction ship and the third construction ship hoist the submarine cable end to the deck of the second construction ship from the arc plates at two sides through the crane, the guide wheels are arranged at proper positions on the deck, the fishing and the traction of the submarine cable are carried out by using the winch on the deck and the auxiliary of the deck crane, the monitoring is implemented in the traction process, and smooth and non-bending submarine cable fishing is ensured;

firstly, checking the water inflow condition of two ends of a submarine cable, cutting off the submarine cable which is dragged by external force when the two ends of the submarine cable are in water inflow and salvaged (each end is cut off by about 5-10 m), then pulling each submarine cable by about 25m, conveying the submarine cable end to a submarine cable joint chamber, ensuring that the two submarine cables are parallel and cross by about 7m, fixing the submarine cable on a platform deck, ensuring that the submarine cable is not displaced on the platform, and fixing the submarine cable in a double fixing mode, namely fixing the submarine cable on the edge of a ship and the outside of an access joint chamber, wherein the submarine cable buffering space can be reserved in the middle, and simultaneously, 6-8 brackets for raising the submarine cable by 0.5m are arranged on the platform ship, and fixing the submarine cable on a manufacturing platform;

(7) And (3) manufacturing a hard joint:

before optical fiber fusion, the optical fibers in the submarine cable at the two ends for manufacturing the hard joint are subjected to one-time on-off attenuation detection, after the optical fibers are fused, the optical cable splice box is placed in the shell and hung into the sea, and when the hard joint is buried, the hard joint and the central axis of the submarine cable are ensured to be in the same straight line; fishing the submarine cable on the operation platform, and testing the insulation performance of the submarine cable;

(8) Armor stripping:

when the submarine cable is in place, the submarine cable needs to be staggered for 7 meters due to the fact that the optical fibers are connected, the armor of about 7 meters is stripped backwards from the middle position of the work shed, each 2 meters of stripped armor length is reserved, the submarine cable at the stripping end is stripped, the reserved staggered length of 1.5 meters is reserved, and then the rest part is cut off;

(9) Optical fiber fusion and mechanical protection:

after the intermediate joint is manufactured, the optical cable is connected and the optical cable joint box is installed; on the premise of ensuring quality and safety, the installation of the protective shell is synchronously carried out; after the protective shell is installed, the polyurethane glue is poured into the glue pouring holes;

(10) Sinking the submarine cable joint: after the submarine cable hard joint passes the completion test, removing the temporary joint manufacturing room, emptying the deck, and preparing a hanging beam, a hanging strip and a shackle;

binding the sea cables with steel wire ropes of about 30 meters at two ends of the joint on the sea cable, marking each 5 meters with paint with two different colors, taking care of a special person, then hanging the joint and the bending limiter by using a multi-point hanging tool by using a crane, lying down the arm in a vertical routing direction at the speed of 2-3 meters/min, slowly paying out the sea cable after the steel wire ropes at the left side and the right side are stressed, tightly preventing the sea cable from freely sliding into the sea from a deck so as not to impact the joint and the sea cable, slowly hanging the joint and the sea cable into water until the sea cable is smoothly placed on the sea bed, and keeping the steel wire outwards slightly all the time until the nylon rope and the steel wire are not stressed, and sinking the sea cable in the vertical routing direction at the top end of an omega shape;

after the hard joint is planted, a diver firstly observes whether the hard joint is placed smoothly on the seabed or not and whether a submarine cable is bent or not when the submarine cable is twisted or not after the hard joint is planted, and simultaneously performs exploring and beacon dotting on the submarine cable track near the end head, and then removes a lifting appliance and a rope, and recovers an upper deck; the distance between the two groups of hard joints is more than 120 m, so that the two groups of hard joints are prevented from interfering with each other for construction, and the subsequent maintenance of the hard joints is ensured to have enough allowance;

(11) Sea cable test detection and protection:

after the construction of the two joints is completed, carrying out sea cable alternating current withstand voltage test and optical fiber test, resetting the interior of the offshore booster station and the sea cable terminal after the test and the test are qualified, finally, selecting a machine to flush and bury the hard joint and the sea cable on the exposed seabed, wherein the flush and burying depth is not less than 2 meters, and recording the routing coordinates and the burying depth of the sea cable and the joint.

2. The submarine cable salvage and repair method according to claim 1, further comprising: the distance L between the upper sea cable position of the arc plate and the end of the original sea cable is (L-L1) 2 is more than or equal to (h0+h3+h4) +L2, L1 is the sea cable deck length, L2 is the linear distance from the original sea cable, h3 is the highest tide depth, and h4 is the model depth.

3. The submarine cable salvage and repair method according to claim 1, further comprising: the distance L0 between the upper sea cable position of the arc plate and the end of the new sea cable is (L0-L1) 2 is not less than (h0+h3+h4) +L3, L1 is the length of the upper sea cable deck, L3 is the linear distance from the upper sea cable, h3 is the highest tide depth, and h4 is the model depth.

4. The submarine cable salvage and repair method according to claim 1, further comprising: the edge of the diving cage is required to be flush with the outermost board of the ship body.

5. The submarine cable salvage and repair method according to claim 1, further comprising: the fence is of a steel structure with the height of 2 m.

6. The submarine cable salvage and repair method according to claim 1, further comprising: sea cable fixing bollards are welded on two sides of a sea cable channel behind the arc plates and are used for fixing sea cables.

7. The submarine cable salvage and repair method according to claim 4, further comprising: the hard joint comprises a 220kV integral prefabricated insulating part middle joint, a joint protection shell and bending limiters, wherein a group of bending limiters are arranged at two ends of each joint, the diameter of the hard joint after the assembly is completed is about 1m, the total length of the hard joint is about 27m, and the two ends of the hard joint are respectively provided with 10m bending limiters.

8. The submarine cable salvage and repair method according to claim 1, further comprising: the hanging beam is 12 m, the bearing is more than 20T, the bearing is more than 10T, and the bearing is more than 10T; the top of the hanging beam is provided with two first hanging points, and the bottom of the hanging beam is provided with eight second hanging points.

9. The submarine cable salvage and repair method according to claim 1, further comprising: the buried plow is thrown and operated according to the following procedures:

(1) a plow is arranged to lift and put in the middle of the trolley;

(2) the submarine cable is put into the abdomen of the buried plow, the door plate is closed, and the moving ship controls the submarine cable water inlet angle to be 45-60 degrees, so that the bending radius of the submarine cable when the buried plow is put in is ensured;

(3) lifting the buried plow, and moving the trolley to the bow to allow the trolley to go out of the buried plow and enter the water space;

(4) starting a water pump, and checking the pressure of the water pump;

(5) moving the ship and simultaneously releasing the submarine cable, and slowly placing the buried plow on the seabed;

(6) starting a buried depth monitoring system;

(7) the worker and the boat are anchored, and traction and burying operation are started.

10. The submarine cable salvage and repair method according to claim 1, further comprising: the intermediate joint comprises a plurality of small joints which are arranged in a staggered way up and down.