An underwater trenching and cable laying device and system

Abstract

The present application belongs to the technical field of underwater trenching and cable laying, and particularly relates to an underwater trenching and cable laying device and operation system. The device comprises a main frame, at least two jet pump assemblies; the at least two jet pump assemblies are symmetrically arranged on the main frame, each jet pump assembly comprises a jet pump body, a mounting rack and two sets of angle adjusting mechanisms, and the inlet of the jet pump body is detachably provided with a suction member, and the port of the suction member extends downward. After the jet pump assembly is started, high-pressure water flow is directionally sprayed from the nozzle to scour the seabed to form a trench, and at the same time, the suction member extending downward at the inlet synchronously sucks the disturbed silt to complete the trenching and cable laying preparation; the two sets of independent angle adjusting mechanisms integrated in each jet pump assembly are used to precisely control the nozzle to swing left and right in a first vertical plane and to control the nozzle to swing forward and backward in a second vertical plane, and the two sets of angle adjusting mechanisms are cooperatively linked to realize the continuous and dead-angle-free 360° omnidirectional flexible adjustment of the spraying direction of the nozzle.

Description

Technical Field

[0001] This invention belongs to the field of underwater trenching and cable laying technology, specifically relating to an underwater trenching and cable laying device and operating system. Background Technology

[0002] Currently, the mainstream equipment for laying submarine cables mainly includes towed jet shovels, towed laying shovels, and self-propelled trenchers. Although these devices have certain operational capabilities under specific working conditions, they generally suffer from poor adaptability. They are usually only suitable for flat, homogeneous sandy or muddy seabeds and are difficult to deal with complex terrains and geological conditions such as sand dunes, reefs, and hard clay.

[0003] It is particularly noteworthy that the nozzle direction adjustment mechanism of existing jet flushing equipment has significant limitations, making it difficult to achieve 360° omnidirectional adjustment. The jet nozzles of traditional equipment can usually only be adjusted to a limited angle within a single plane (such as only left and right swinging or only forward and backward pitching), and cannot flexibly adjust the jet direction according to complex seabed topography and diverse operational needs (such as trenching, backfilling, pre-sweeping, and cable exploration). This results in low efficiency or even inability to complete operations when facing irregular seabed topography, hard soil layers, or special operational scenarios. Summary of the Invention

[0004] This application provides an underwater trenching and cable laying device and operating system, which overcomes the shortcomings of existing jet pump nozzles that have limited adjustment range and can only be adjusted in a single plane, and realizes 360° omnidirectional flexible adjustment of jet pump nozzles for complex seabed topography during underwater trenching and cable laying operations.

[0005] In a first aspect, this application provides an underwater trenching and cable-laying device, comprising:

[0006] The main frame is equipped with a lifting device for connecting the steel wire rope of the ship's crane.

[0007] At least two jet pump assemblies are symmetrically arranged on the main frame. Each jet pump assembly includes a jet pump body, a mounting bracket, and two sets of angle adjustment mechanisms.

[0008] The inlet of the jet pump body is detachably equipped with a suction component, and the port of the suction component extends downward.

[0009] The mounting bracket surrounds and is connected to the jet pump body;

[0010] The two sets of angle adjustment mechanisms are used to adjust the left-right swing and front-back swing of the nozzle of the jet pump body, respectively, so that the nozzle of the jet pump body can achieve 360° omnidirectional adjustment.

[0011] Optionally, the angle adjustment mechanism includes at least two shaft support structures coaxially mounted on the main frame, a positioning pin mounted on at least one of the shaft support structures, and a limiting plate mounted on the mounting bracket. The limiting plate has multiple positioning holes arranged in an arc shape for inserting the positioning pin. The mounting bracket is connected to the shaft support structure via a rotating shaft.

[0012] Optionally, the main frame is provided with two linear adjustment structures for adjusting the lateral spacing between the two jet pump assemblies. Each linear adjustment structure includes two sets of limiting holes opened on the main frame. Multiple limiting holes in each set are distributed along a straight line. The shaft support structure is connected to the corresponding limiting holes through multiple fasteners.

[0013] Optionally, the multiple positioning holes on the limiting plate are evenly distributed along the arc, so that the nozzle of the jet pump body can swing within a range of -60° to 60° in the horizontal plane with the initial reference position as the center.

[0014] Optionally, the limiting plate has 7 to 15 positioning holes.

[0015] Optionally, the underwater trenching and cable laying device further includes an umbilical cable, a float bend limiter fitted onto the umbilical cable, and a connecting structure disposed at the bottom of the float bend limiter. The umbilical cable is connected to the surface power supply and control system to provide power supply and control signals for the underwater controlled flow trenching and cable laying operation system. The float bend limiter provides a certain buoyancy to the umbilical cable and limits excessive bending of the umbilical cable. The connecting structure is connected to the main frame.

[0016] Optionally, the underwater trenching and cable laying device further includes a terminal box, a compensator, an electronics compartment, protective covers, and sonar; wherein, the terminal box connects to the umbilical cable and has a built-in transformer to convert the high voltage in the umbilical cable and connect and process various underwater electrical signals; the compensator is used to compensate for hydraulic oil pressure underwater and serves as an oil tank; the electronics compartment contains various electrical components for receiving and processing underwater signals; multiple protective covers are set on the outside of the main frame, and sonar is installed inside the protective covers.

[0017] Optionally, the float bend limiter includes a split inner sheath and a split outer sheath. The outer sheath is assembled with fasteners and fitted onto two adjacent inner sheaths and snapped in place. The inner sheath is fitted onto the umbilical cable by the action of the outer sheath.

[0018] Optionally, the connection structure includes a first connection portion connected to the inner sheath at the bottom end and a second connection portion connected to the first connection portion. The first connection portion is provided with a force-bearing clamp for holding the umbilical cable. A force-measuring pin is connected between the first connection portion and the second connection portion. An annular position sensor coaxial with the force-measuring pin is provided on the second connection portion. The annular position sensor forms a relative rotational relationship with the secondary main structure. A magnet is provided on the first connection portion. The magnet moves on the annular position sensor to generate a changing magnetic field signal.

[0019] Optionally, the inner wall of the inner sheath is shaped as a bidirectional outward-expanding trumpet, with radially protruding snap-fit ​​edges at both ends that snap into the inner wall of the outer sheath. The two ends of the outer sheath are provided with arc-shaped end faces, and adjacent outer sheaths can be bent to fit together to form a certain bending radius.

[0020] Optionally, a roller is provided on the first connecting part, and the roller is in rolling engagement with the umbilical cable.

[0021] Secondly, this application provides an underwater trenching and cable laying operation system, comprising:

[0022] The underwater trenching and cable laying device described above;

[0023] Mother ship, used to provide equipment installation, ship power, and positioning;

[0024] The umbilical cable connects to the surface power supply and control system, providing power and control signals to the operating system.

[0025] The control cabin is used to operate the control area and is electrically connected to the umbilical cable.

[0026] The power distribution compartment connects the ship's electrical system and the umbilical cable, providing power and frequency conversion control for the underwater controlled flow trencher;

[0027] A crane, connected to the lifting device of the underwater trenching and cable laying apparatus via a steel wire rope;

[0028] An umbilical cable winch is used to store the umbilical cable, connect to the underwater trenching and cable laying device, and control the length and tension of the umbilical cable.

[0029] At least two wire rope winches are respectively set on both sides of the umbilical cable winch, and are connected to both sides of the underwater trenching and cable laying device by wire rope. The attitude of the underwater trenching and cable laying device is adjusted by controlling the length and tension of the wire rope.

[0030] The hydraulic power unit provides hydraulic power for the wire rope winch and the umbilical cable winch.

[0031] The beneficial effects of this application are:

[0032] The underwater trenching and cable laying device provided in the first aspect of this application is operated by a ship crane using a lifting device to lower it to the seabed work area. After the symmetrically arranged jet pump assembly is started, high-pressure water jets are sprayed directionally from the nozzle to scour the seabed and form trenches. At the same time, the suction component extending downward at the inlet simultaneously suctions and agitates the sediment to complete the trenching and cable laying preparation. Its core lies in the two independent angle adjustment mechanisms integrated in each jet pump assembly—one set precisely controls the nozzle to swing left and right in the first vertical plane, and the other set controls the nozzle to swing back and forth in the second vertical plane. The first vertical plane and the second vertical plane are perpendicular to each other. The two work together to enable the nozzle spray direction to be continuously and flexibly adjusted in all directions of 360° without dead angles. This breakthrough overcomes the technical bottleneck of traditional jet equipment where the nozzle is limited to a single plane for adjustment. The device can dynamically optimize the jet angle and force distribution in real time for complex seabed terrains such as sand dunes, reefs, and hard clay, as well as diverse operational needs such as trenching, backfilling, pre-scanning, and cable exploration. This significantly improves the device's adaptability to operations in heterogeneous seabed environments, trenching efficiency, and trenching quality.

[0033] The underwater trenching and cable laying system provided in the second aspect of this application integrates the aforementioned multifunctional underwater trenching and cable laying device with modules such as the control room, power distribution room, umbilical cable winch, wire rope winch, and hydraulic power unit on the mother ship platform, constructing a highly efficient, flexible, and intelligent subsea cable laying solution. This system utilizes umbilical cables for power transmission and real-time signal interaction, combined with wire rope winches on both sides for active three-dimensional attitude control of the underwater device, significantly improving its stability and operational accuracy in complex seabed terrain. Simultaneously, a crane facilitates rapid hoisting and retrieval, the umbilical cable winch precisely manages cable length and tension, provides variable frequency power support to the power distribution room, and the hydraulic power unit uniformly drives key deck equipment, effectively ensuring operational continuity and safety. This allows the system to complete the entire process of trenching, cable laying, and backfilling in one integrated manner without the need for multi-ship coordination or equipment switching, significantly shortening the construction cycle, reducing ship relocation costs, and enhancing adaptability to harsh conditions such as deep water, strong currents, and irregular seabed conditions, providing highly reliable and efficient technical support for the construction of subsea energy and communication infrastructure. Attached Figure Description

[0034] Figure 1 This is a schematic diagram of the underwater trenching and cable laying device provided in the embodiments of this application;

[0035] Figure 2 This is a schematic diagram of the structure of the jet pump assembly provided in the embodiments of this application;

[0036] Figure 3 This is a schematic diagram of the structure of the jet pump body provided in the embodiments of this application;

[0037] Figure 4This is a schematic diagram of the float bending limiter and connecting structure provided in the embodiments of this application;

[0038] Figure 5 This is a cross-sectional structural diagram of the float bending limiter provided in the embodiments of this application;

[0039] Figure 6 A schematic diagram of the cable probing status of the underwater trenching and cable laying device provided in the embodiments of this application;

[0040] Figure 7 A schematic diagram of the trenching state of the underwater trenching and cable laying device provided in the embodiments of this application;

[0041] Figure 8 A schematic diagram of the trenching and pumping backfilling states of the underwater trenching and cable laying device provided in the embodiments of this application;

[0042] Figure 9 A schematic diagram of the pre-sweeping state of the underwater trenching and cable laying device provided in the embodiments of this application;

[0043] Figure 10 A schematic diagram of the lateral backfilling state of the underwater trenching and cable laying device provided in the embodiments of this application;

[0044] Figure 11 A schematic diagram of the centering backfill state of the underwater trenching and cable laying device provided in the embodiments of this application;

[0045] Figure 12 A top view of the underwater trenching and cable laying system in operation state 1 provided in the embodiments of this application;

[0046] Figure 13 This is a front view of the underwater trenching and cable laying system in operation state 1 provided in the embodiments of this application;

[0047] Figure 14 A top view of the underwater trenching and cable laying system in operation state 2 provided in the embodiments of this application;

[0048] Figure 15 This is a front view of the underwater trenching and cable laying system in operation state two, as provided in the embodiments of this application.

[0049] In the diagram: 1000, Underwater trenching and cable laying device; 100, Main frame; 110, Lifting gear; 120, Terminal box; 130, Compensator; 140, Electronics compartment; 150, Protective cover; 160, Limiting hole; 200, Jet pump assembly; 210, Jet pump body; 211, Suction component; 220, Mounting bracket; 230, Angle adjustment mechanism; 231, Shaft support structure; 232, Positioning pin; 233, Limiting plate; 234, Rotating shaft; 300, Umbilical cable; 400, Float bend limiter; 410, Inner sheath; 411, Clamping flange; 4 20. Outer sheath; 421. Arc-shaped end face; 500. Connecting structure; 510. First connecting part; 520. Second connecting part; 530. Load-bearing clamp; 540. Force-measuring pin; 550. Annular position sensor; 560. Magnet; 2000. Mother ship; 2010. Control room; 2020. Power distribution room; 2030. Crane; 2040. Umbilical cable winch; 2050. Wire rope winch; 2060. Hydraulic power unit; 2070. Winch wire rope; 2071. Crossed wire rope; 2080. Counterweight; 2090. Guide groove. Detailed Implementation

[0050] To make the technical problems, technical solutions, and beneficial effects to be solved by this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and are not intended to limit the scope of this application.

[0051] like Figures 1-5 As shown, in a first aspect, embodiments of this application provide an underwater trenching and cable-laying device comprising:

[0052] The main frame 100 is equipped with a lifting device 110 for connecting the wire rope of the ship crane.

[0053] At least two jet pump assemblies 200 are symmetrically arranged on the main frame 100. Each jet pump assembly 200 includes a jet pump body 210, a mounting bracket 220, and two sets of angle adjustment mechanisms 230. The inlet of the jet pump body 210 is detachably provided with a suction component 211, the port of which extends downward. The two sets of angle adjustment mechanisms 230 are used to adjust the left-right swing and back-forward swing of the nozzle of the jet pump body 210, respectively, so that the nozzle of the jet pump body 210 can achieve 360° omnidirectional adjustment.

[0054] The underwater trenching and cable laying device 1000 provided in the first aspect of this application is lowered to the seabed operation area by a ship crane using a lifting device 110. After the symmetrically arranged jet pump assembly 200 is started, high-pressure water jets are sprayed directionally from the nozzle to scour the seabed and form trenches. At the same time, the suction component 211 extending downward at the inlet simultaneously suctions the disturbed mud and sand to complete the trenching and cable laying preparation. Its core lies in the two independent angle adjustment mechanisms 230 integrated in each jet pump assembly 200. One set precisely controls the nozzle to swing left and right in the first vertical plane, and the other set controls the nozzle to swing back and forth in the second vertical plane. The first vertical plane and the second vertical plane are perpendicular to each other. The two work together to enable the nozzle spray direction to be continuously and flexibly adjusted in all directions of 360° without dead angles. This breakthrough overcomes the technical bottleneck of traditional jet equipment where the nozzle is limited to a single plane for adjustment. The device can dynamically optimize the jet angle and force distribution in real time for complex seabed terrains such as sand dunes, reefs, and hard clay, as well as diverse operational needs such as trenching, backfilling, pre-scanning, and cable exploration. This significantly improves the device's adaptability to operations in heterogeneous seabed environments, trenching efficiency, and trenching quality.

[0055] In some possible implementations, the angle adjustment mechanism 230 includes at least two shaft support structures 231 mounted on the main frame 100 and coaxially arranged, a positioning pin 232 mounted on at least one shaft support structure 231, and a limiting plate 233 mounted on the mounting bracket 220. The limiting plate 233 has multiple positioning holes arranged in an arc shape for inserting the positioning pin 232. The mounting bracket 220 is connected to the shaft support structure 231 through a rotating shaft 234.

[0056] Specifically, the angle adjustment mechanism 230, which enables the jet pump body 210 to swing left and right around the corresponding axis, is achieved by setting a pluggable positioning pin 232 on one of the shaft support structures 231. This works in conjunction with a limiting disc 233 on the mounting bracket 220—which has multiple positioning holes arranged in an arc shape. When the jet direction needs to be adjusted, the operator pulls out the positioning pin 232, rotates the mounting bracket 220 to the desired angle, and then reinserts the positioning pin into the corresponding positioning hole, thus locking the specific deflection angle of the jet pump nozzle towards both sides. This allows for flexible adjustment of the jet scouring angle before or during underwater operations based on seabed topography and trench width requirements, enhancing the device's adaptability to complex geology and different cable laying depths.

[0057] Specifically, in the angle adjustment mechanism 230 that enables the jet pump body 210 to swing back and forth around the corresponding axis, the jet pump body 210 is connected to the mounting frame 220 via at least two coaxially arranged shaft support structures 231. The mounting frame 220 is rotatably hinged to the support structures via a rotating shaft 234. One of the shaft support structures 231 has a removable positioning pin 232, and a corresponding limiting disc 233 is fixed to the mounting frame 220. This limiting disc has multiple positioning holes arranged in an arc shape. Before or during operation, the operator can pull out the positioning pin 232 according to the seabed slope, burial depth, or scouring efficiency requirements, rotate the jet pump body 210 around the rotating shaft 234 to the desired pitch angle, and then insert the positioning pin 232 into the corresponding positioning hole to lock the angle. This allows the nozzle to adapt to both horizontal scouring on a gentle seabed and directional erosion on slopes or undulating terrain, further improving the operational flexibility and trenching accuracy of the device in complex seabed environments.

[0058] In some possible implementations, the main frame 100 is provided with two linear adjustment structures for adjusting the lateral spacing between the two jet pump assemblies 200. Each linear adjustment structure includes two sets of limiting holes 160 opened on the main frame 100. Each set of multiple limiting holes 160 is distributed along a straight line. The shaft support structure 231 is connected to the corresponding limiting holes 160 through multiple fasteners.

[0059] Specifically, each linear adjustment structure includes two sets of limiting holes 160 distributed in a transverse straight line, located in the corresponding installation area of ​​the main frame 100; the shaft support structure 231 is connected and fixed to the selected limiting holes 160 by multiple fasteners (such as bolts or pins). When it is necessary to adjust the spacing of the jet pump assembly 200, the operator loosens the fasteners, slides the shaft support structure 231 to the target position along the arrangement direction of the limiting holes 160, and then re-tightens the fasteners to complete the positioning. This linear adjustment structure is simple in structure and reliable in adjustment. The trench width can be flexibly set according to the cable diameter, burial depth and seabed conditions before operation, improving the adaptability of the device to diverse cable laying tasks.

[0060] In some possible implementations, multiple positioning holes on the limiting disk 233 are evenly distributed along an arc, so that the nozzle of the jet pump body 210 can swing within a range of -60° to 60° in the horizontal plane with the initial reference position as the center.

[0061] Specifically, based on the initial neutral position of the jet pump body 210, the jet pump body 210 can be adjusted to the left or right by a maximum deflection angle of 60° each, with a total adjustment range of 120°. This allows the jet pump nozzle to flexibly adjust the scouring direction within a wide lateral angle range according to seabed topography, trench width, or operational requirements. The jet pump body 210 can also be adjusted forward or backward by a maximum deflection angle of 60° each, with a total adjustment range of 120°. This allows the jet pump body 210 to flexibly adjust the incident angle of the jetting water flow according to seabed undulations, burial depth, or scouring efficiency requirements. For example, a steeper downward thrust angle can be used in harder seabeds to enhance the erosion effect, or the nozzle orientation can be adjusted in sloping terrain to maintain trench continuity. By inserting the positioning pin 232 into the positioning hole at the corresponding angle, the desired jetting angle can be quickly and stably locked.

[0062] In some possible implementations, the limiting plate 233 has 7 to 15 positioning holes. For example, the limiting plate 233 may have 7, 8, 9, 10, 11, 12, 13, 14, or 15 positioning holes.

[0063] In some other possible implementations, the angle adjustment mechanism 230 also includes a linear telescoping device and a rotary driver, with the actuator end of the linear telescoping device connected to the positioning pin 232 and the rotary driver drivenly connected to the rotating shaft 234.

[0064] Specifically, the angle adjustment mechanism 230 further integrates a linear telescoping device and a rotary actuator to automate the lateral deflection angle of the jet pump body 210. The linear telescoping device (such as a hydraulic cylinder or electric push rod) has its actuator connected to the positioning pin 232, automatically controlling the insertion or removal of the positioning pin. The rotary actuator (such as a rotary motor or servo motor) is connected to the rotating shaft 234, actively driving the mounting bracket 220 and the jet pump body 210 to rotate around the rotating shaft 234 to the target angle after the positioning pin is removed. When the nozzle's lateral orientation needs adjustment, the control system first instructs the linear telescoping device to retract, disengaging the positioning pin 232 from the positioning hole on the limit plate 233. Then, the rotary actuator drives the jet pump assembly 200 to rotate to the preset angle. Once in position, the linear telescoping device extends again, precisely inserting the positioning pin into the corresponding positioning hole to lock it in place. This upgrades traditional manual adjustment to remote or automatic control, significantly improving operational efficiency, adjustment accuracy, and underwater operational safety, making it particularly suitable for cable laying operations in deep water or highly dynamic sea conditions.

[0065] In some possible implementations, the device also includes an umbilical cable 300, a float bend limiter 400 fitted onto the umbilical cable 300, and a connecting structure 500 disposed at the bottom of the float bend limiter 400. The umbilical cable 300 is connected to the surface power supply and control system to provide power supply and control signals for the underwater control flow trenching and cable laying operation system. The float bend limiter 400 provides a certain buoyancy to the umbilical cable 300 and limits the excessive bending of the umbilical cable 300. The connecting structure 500 is connected to the main frame 100.

[0066] Specifically, the umbilical cable 300 is used to connect the power supply and control unit of the surface vessel, providing continuous power and real-time control signals for underwater operations. A float bend limiter 400 is fitted around the umbilical cable 300, which consists of multiple bend-limiting segments integrated with buoyancy material. This provides moderate positive buoyancy to the umbilical cable 300, reducing its own weight's downward pull on the main frame 100 and maintaining the cable's stable suspension in the water. Furthermore, the structural rigidity limits excessive bending and kinking of the umbilical cable 300 under dynamic ocean currents or vessel movement, preventing damage to internal cables or optical fibers. A dedicated connection structure 500 (such as a flange, lug, or quick-connect coupling) is located at the bottom of the float bend limiter 400. This connection structure 500 is firmly connected to the main frame 100, ensuring that the entire umbilical cable 300 system moves in tandem with the operating device, avoiding wear or stress concentration caused by relative displacement.

[0067] In some possible implementations, the underwater trenching and cable laying device 1000 also includes a terminal box 120, a compensator 130, an electronics compartment 140, a protective cover 150, and a sonar; wherein, the terminal box 120 is connected to the umbilical cable 300 and has a built-in transformer to transform the high voltage in the umbilical cable 300 and connect and process various underwater electrical signals; the compensator 130 is used to compensate for hydraulic oil pressure underwater and serves as an oil tank; the electronics compartment 140 has various electrical components built-in for receiving and processing underwater signals; multiple protective covers 150 are arranged on the outside of the main frame 100, and sonar is installed inside the protective covers 150.

[0068] Specifically, the terminal box 120 is connected to the end of the umbilical cable 300 and integrates a high-voltage isolation transformer and a signal processing unit. It is used to convert the high-voltage power transmitted by the umbilical cable 300 into a safe operating voltage suitable for underwater equipment, and to collect, condition and perform preliminary processing on analog or digital signals from various sensors (such as force pin 540, position sensor, depth gauge, etc.) to achieve power distribution and information aggregation.

[0069] As a pressure balancing unit of the hydraulic system, the compensator 130 automatically adjusts the internal hydraulic oil volume according to the water depth through an elastic diaphragm or piston structure to compensate for the compression or expansion of the oil chamber caused by changes in environmental static pressure. It not only maintains the stable operation of the hydraulic system, but also serves as a small oil tank, reducing dependence on external oil sources.

[0070] The electronic compartment 140 is sealed and installed inside or near the main frame 100. It has a built-in controller, power module, communication interface and data processing unit. It is responsible for receiving surface commands, parsing sensor data, driving actuators (such as linear telescoping devices and rotary actuators), and supporting local closed-loop control or status feedback.

[0071] The protective cover 150 is located on the outside of the main frame 100. It adopts a streamlined pressure-resistant structure and integrates forward-looking or side-scan sonar inside. It is used to detect the seabed topography, obstacles and the location of laid cables in real time, providing high-precision perception support for trenching path planning and obstacle avoidance.

[0072] In some possible implementations, such as Figure 4 As shown, the float bend limiter 400 includes an inner sheath 410 with a segmented structure and an outer sheath 420 with a segmented structure. The outer sheath 420 is assembled with fasteners and sleeved on two adjacent inner sheaths 410 and snapped in place. The inner sheath 410 is sleeved on the umbilical cable 300 by the action of the outer sheath 420.

[0073] Specifically, the inner sheath 410 consists of two or more axially aligned semi-annular components, which can be conveniently wrapped around the outside of the umbilical cable 300. The outer sheath 420 is also a segmented structure, with adjacent inner sheath 410 segments clamped and fixed together by fasteners (such as bolts, clamps, or quick-release pins). Simultaneously, its inner cavity contour matches the outer surface of the inner sheath 410, and radial compression ensures that the inner sheath 410 fits tightly against the umbilical cable 300, achieving a secure hold. This not only facilitates on-site installation or replacement of the bend limiter unit without cutting the umbilical cable 300, but also effectively limits the local bending radius of the umbilical cable 300 through the synergistic constraint of the inner and outer sheaths 420, preventing excessive bending. Furthermore, buoyancy materials (such as closed-cell foam or lightweight composite floats) can be integrated into the interior or surface of the outer sheath 420, providing the required buoyancy while maintaining a compact overall structure, pressure resistance, and erosion resistance, suitable for long-term operations in complex deep-water conditions.

[0074] In some possible implementations, the connection structure 500 includes a first connection portion 510 connected to the inner sheath 410 at the bottom end and a second connection portion 520 connected to the first connection portion 510. The first connection portion 510 is provided with a force-bearing clamp 530 for holding the umbilical cable 300. A force-measuring pin 540 is connected between the first connection portion 510 and the second connection portion 520. An annular position sensor 550 coaxial with the force-measuring pin 540 is provided on the second connection portion 520. A magnet 560 is provided on the first connection portion 510. The magnet 560 moves on the annular position sensor 550 to generate a changing magnetic field signal.

[0075] Specifically, the annular position sensor 550 and the magnet 560 constitute a non-contact angle detection unit. When the main frame 100 or the umbilical cable 300 swings, it will cause the first connecting part 510 and the second connecting part 520 to rotate relative to each other around the force-measuring pin 540, thereby causing the magnet 560 to move around the periphery of the annular position sensor 550. Its multipole magnetic field vector changes continuously relative to the Hall element or magnetoresistive array in the annular sensor. The sensor converts the magnetic field angle information into a high-precision electrical signal (such as analog voltage or digital encoding) in real time. The force-measuring pin 540 accurately senses the tension transmitted by the umbilical cable 300 to the connecting structure 500, preventing the risk of breakage caused by ship movement, water flow impact, or excessive tension during deployment and recovery. The annular position sensor 550 continuously obtains the deflection angle of the umbilical cable 300 relative to the main frame 100 by detecting the change in the circumferential position of the magnet 560, effectively warning of excessive bending of the umbilical cable 300 or accidental entry into dangerous areas such as jet pump blades or sharp angles of the frame. Meanwhile, the cable bearing clamp 530 and small roller combination structure set near the force measuring pin 540 enable the umbilical cable 300 to smoothly transition along the roller under stress, avoiding direct hard contact or friction between its free end and metal parts, and significantly reducing the risk of wear on the outer sheath 420 and fatigue damage to the internal conductor.

[0076] In some possible implementations, such as Figure 5 As shown, the inner wall of the inner sheath 410 is shaped as a two-way outward flared trumpet, with radially protruding snap-fit ​​flanges 411 at both ends that snap into the inner wall of the outer sheath 420. The outer sheath 420 has arc-shaped end faces at both ends, and adjacent outer sheaths 420 can be bent to fit together to form a certain bending radius.

[0077] Specifically, the outer sheath 420 is matched with the inner wall contour, achieving axial limiting and circumferential fixation through fitting. The two end faces of the outer sheath 420 are machined into smooth arc surfaces. When multiple outer sheath 420 units are connected sequentially, the arc-shaped end faces 421 of adjacent units can slide against each other, allowing the overall structure to flexibly deform along the bending direction under external loads or water flow, thus forming a continuous and controllable bending shape and ensuring that the actual bending radius is always greater than the safe minimum bending radius of the umbilical cable 300. This ensures both effective support and bending protection of the umbilical cable 300 by the float bend limiter 400, while also giving it good flexibility and dynamic adaptability.

[0078] In some possible implementations, a roller is provided on the first connecting part 510, and the roller rolls in engagement with the umbilical cable 300. The roller is used to guide the umbilical cable 300 and reduce its frictional resistance during dynamic operations caused by ship rolling, water flow disturbance, or device attitude adjustment.

[0079] To facilitate understanding of the underwater trenching and cable laying device 1000 provided in this embodiment, the following are some operating states.

[0080] (1) such as Figure 6 As shown, the probe cable is used for route detection or monitoring of submarine cable laying status. Equipped with multiple sonar or electrical detection devices, it flies along the submarine cable to detect its working status, span, and burial depth, transmitting cable route information to the water surface. It replaces traditional ROVs, enabling low-cost and flexible operation. By adjusting the direction of the two jet pump bodies 210, it provides a certain lateral force to achieve underwater current resistance, ensuring the stable attitude of the underwater controlled-flow trencher. It should be noted that... Figure 6 The circle at the bottom represents a submarine cable (the same applies below).

[0081] (2) such as Figure 7 As shown, trenching: the jet pump body 210 is vertically downward, and the jet acts vertically on the seabed plane, creating a large pit. By adjusting the height of the underwater control flow trenching machine above the seabed, the rotational speed / pressure of the jet pump body 210, and the distance between the two jet pump bodies 210, the submarine cable is sprayed into the trench. For the suspended section of the submarine cable, this effectively reduces the sand dune wave crest and lowers the cable suspension height.

[0082] (3) such as Figure 8 As shown, trenching and suction backfilling: The jet pump body 210 is equipped with a suction component 211. The jet pump body 210 is vertically downward, and the jet acts vertically on the seabed plane, spraying out a large pit. By adjusting the height of the underwater control flow trenching machine from the seabed, the speed / pressure of the jet pump body 210, the distance between the two jet pump bodies 210, and the distance of the suction port, the submarine cable is sprayed into the trench, and at the same time, the mud and sand on both sides are backfilled into the trench.

[0083] (4) such as Figure 9 As shown, pre-scanning: Before laying the submarine cable, pre-scanning mode is used to treat uneven areas on the seabed, making the route flat and suitable for trenching and cable laying. The two jet pump bodies 210 are tilted towards the center. By adjusting the height of the underwater control flow trencher from the seabed, the pump speed / pressure, and the distance between the two jet pump bodies 210, the jet is converged onto the seabed surface to smooth out the seabed protrusions.

[0084] (5) such as Figure 10 As shown, lateral backfilling: After the submarine cable is laid to the seabed, active backfilling is required. Two jet pump bodies 210 rotate to the same side. By adjusting the height of the underwater control flow trencher from the seabed, the rotational speed / pressure of the jet pump bodies 210, and the distance between the two jet pump bodies 210, the jets are collected and directed to the seabed surface on one side of the submarine cable. This causes the seabed sediment kicked up by the jets to fall and cover the surface of the submarine cable, forming backfill.

[0085] (6) For example Figure 11As shown, backfilling is carried out in a centered manner: After the submarine cable is laid to the seabed, active backfilling is required. Two jet pump bodies 210 rotate outwards. By adjusting the height of the underwater control flow trencher from the seabed, the rotational speed / pressure of the jet pump body 210, and the distance between the two jet pump bodies 210, the jet flow is dispersed to the seabed surface on both sides of the submarine cable, so that the seabed sediment ejected from both sides falls and covers the surface of the submarine cable, forming backfill.

[0086] like Figures 12-15 As shown, in a second aspect, embodiments of this application provide an underwater trenching and cable laying system, comprising:

[0087] The underwater trenching and cable laying device 1000 as described above;

[0088] The mother ship 2000 is used to provide equipment installation, ship power, and positioning.

[0089] The umbilical cable 300 connects to the surface power supply and control system, providing power and control signals to the operating system;

[0090] The control cabin 2010 is used to operate the control area and is electrically connected to the umbilical cable 300;

[0091] The power distribution compartment 2020 connects the ship's power supply and the umbilical cable 300, providing power and frequency conversion control for the underwater controlled flow trencher;

[0092] Crane 2030, with lifting device 110 connected to underwater trenching and cable laying device 1000 via steel wire rope;

[0093] The umbilical cable winch 2040 is used to store the umbilical cable 300, connect to the underwater trenching and cable laying device 1000, and control the length and tension of the umbilical cable 300.

[0094] At least two wire rope winches 2050 are respectively set on both sides of the umbilical cable winch 2040 and connected to both sides of the underwater trenching and cable laying device 1000 by wire rope. The attitude of the underwater trenching and cable laying device 1000 is adjusted by controlling the length and tension of the wire rope.

[0095] The hydraulic power unit 2060 provides hydraulic power to the wire rope winch 2050 and the umbilical cable winch 2040.

[0096] The underwater trenching and cable laying system provided in the second aspect of this application integrates the aforementioned multifunctional underwater trenching and cable laying device 1000 with modules such as the control room 2010, power distribution room 2020, umbilical cable winch 2040, wire rope winch 2050, and hydraulic power unit 2060 on the mother ship 2000 platform, constructing an efficient, flexible, and intelligent subsea cable laying solution. This system utilizes the umbilical cable 300 for power transmission and real-time signal interaction, combined with the two wire rope winches 2050 on both sides for active three-dimensional attitude control of the underwater device, significantly improving its stability and operational accuracy in complex seabed terrain. Simultaneously, the crane 2030 facilitates rapid hoisting and retrieval, the umbilical cable winch 2040 precisely manages cable length and tension, provides variable frequency power support to the power distribution room 2020, and the hydraulic power unit 2060 uniformly drives key deck equipment, effectively ensuring operational continuity and safety. This allows the system to complete the entire process of trenching, cable laying, and backfilling in one integrated manner without the need for multiple vessels to coordinate or switch between multiple devices. This significantly shortens the construction cycle, reduces vessel relocation costs, and enhances the system's adaptability to harsh conditions such as deep water, strong currents, and irregular seabed. It provides highly reliable and efficient technical support for the construction of submarine energy and communication infrastructure.

[0097] The underwater trenching and cable laying system of this embodiment also includes multiple guide grooves 2090 and guide pulleys set on the side of the mother ship 2000. The guide grooves 2090 provide support and guidance for the wire rope, and the guide pulleys provide support and guidance for the umbilical cable 300.

[0098] When in use, the underwater trenching and cable laying device 1000 relies on the mother ship 2000 for attitude and movement control. There are two operating modes for the underwater trenching and cable laying system:

[0099] (1) 1000 steel wire rope direct connection underwater trenching and cable laying device:

[0100] like Figure 12 and Figure 13 As shown, the underwater trenching and cable laying device 1000 has wire ropes 2070 (wire cables) of wire winches 2050 connected to both sides. By raising and lowering the wire winches 2050 on both sides, the tension of the wire ropes 2070 is adjusted to provide lateral force for the underwater trenching and cable laying device 1000, which facilitates attitude adjustment, resists ocean currents, and stabilizes operation. It is mainly used in shallow water.

[0101] (2) The underwater trenching and cable laying device 1000 is connected by two sets of counterweights 2080:

[0102] like Figure 14 and Figure 15As shown, the underwater trenching and cable-laying device 1000 is connected to two sides by cross steel wire ropes 2071, which are in a horizontal position. The ends of the winch steel wire ropes 2070 of the left and right wire winches 2050 are connected to a set of counterweights 2080, which are connected to the cross steel wire ropes 2071. The distance between the counterweights 2080 and the underwater trenching and cable-laying device 1000 is adjustable. By increasing the attitude adjustment arm of the underwater trenching and cable-laying device 1000, the attitude of the device is more easily controlled, effectively resisting ocean currents and ensuring stable operation, making it suitable for deep water. Compared to directly connecting the underwater trenching and cable-laying device 1000 with steel wire ropes, this solution offers better control, although the cost is slightly higher.

[0103] Those skilled in the art should understand that the discussion of any of the above embodiments is merely exemplary and is not intended to imply that the scope of protection of this application is limited to these examples; under the concept of this application, the technical features of the above embodiments or different embodiments can also be combined, the steps can be implemented in any order, and there are many other variations of different aspects of one or more embodiments of this application as described above, which are not provided in detail for the sake of brevity.

[0104] One or more embodiments in this application are intended to cover all such substitutions, modifications, and variations that fall within the broad scope of this application. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of one or more embodiments in this application should be included within the protection scope of this application.

Claims

1. An underwater trenching and cable laying device, characterized in that, include: The main frame (100) is equipped with a lifting device (110) for connecting the steel wire rope of the ship crane; At least two jet pump assemblies (200) are symmetrically arranged on the main frame (100). Each jet pump assembly (200) includes a jet pump body (210), a mounting bracket (220), and two sets of angle adjustment mechanisms (230). The inlet of the jet pump body (210) is detachably provided with a suction component (211), and the port of the suction component (211) extends downward. The mounting bracket (220) surrounds and is connected to the jet pump body (210); The two sets of angle adjustment mechanisms (230) are used to adjust the left and right swing and the front and back swing of the nozzle of the jet pump body (210) respectively, so that the nozzle of the jet pump body (210) can achieve 360° omnidirectional adjustment; The underwater trenching and cable laying device (1000) also includes an umbilical cable (300), a float bend limiter (400) sleeved on the umbilical cable (300), and a connecting structure (500) set at the bottom of the float bend limiter (400). The umbilical cable (300) is connected to the surface power supply and control system to provide power supply and control signals for the underwater control flow trenching and cable laying operation system. The float bend limiter (400) provides buoyancy to the umbilical cable (300) and limits the excessive bending of the umbilical cable (300). The connecting structure (500) is connected to the main frame (100). The float bend limiter (400) includes a split inner sheath (410) and a split outer sheath (420). The outer sheath (420) is assembled with fasteners and sleeved on two adjacent inner sheaths (410) and snapped in place. The inner sheath (410) is sleeved on the umbilical cable (300) by the action of the outer sheath (420). The connection structure (500) includes a first connection part (510) connected to the inner sheath (410) at the bottom end and a second connection part (520) connected to the first connection part (510). The first connection part (510) is provided with a force-bearing clamp (530) for clamping the umbilical cable (300). A force-measuring pin (540) is connected between the first connection part (510) and the second connection part (520). The second connection part (520) is provided with an annular position sensor (550) coaxial with the force-measuring pin (540). The first connection part (510) is provided with a magnet (560). The magnet (560) moves on the annular position sensor (550) to generate a changing magnetic field signal.

2. The underwater trenching and cable laying device according to claim 1, characterized in that, The angle adjustment mechanism (230) includes at least two shaft support structures (231) disposed on the main frame (100) and coaxially, a positioning pin (232) disposed on at least one of the shaft support structures (231), and a limiting plate (233) disposed on the mounting bracket (220). The limiting plate (233) has a plurality of positioning holes for inserting the positioning pin (232) and distributed in an arc shape. The mounting bracket (220) is connected to the shaft support structure (231) through a rotating shaft (234).

3. The underwater trenching and cable laying device according to claim 2, characterized in that, The main frame (100) is provided with two linear adjustment structures for adjusting the lateral spacing between the two jet pump assemblies (200). Each linear adjustment structure includes two sets of limiting holes (160) opened on the main frame (100). Each set of multiple limiting holes (160) is distributed along a straight line. The shaft support structure (231) is connected to the corresponding limiting holes (160) through multiple fasteners.

4. The underwater trenching and cable laying device according to claim 2, characterized in that, The multiple positioning holes on the limiting plate (233) are evenly distributed along the arc, so that the nozzle of the jet pump body (210) can swing within a range of -60° to 60° in the horizontal plane with the initial reference position as the center.

5. The underwater trenching and cable laying device according to claim 4, characterized in that, The limiting plate (233) has 7 to 15 positioning holes.

6. The underwater trenching and cable laying device according to claim 1, characterized in that, The underwater trenching and cable laying device (1000) also includes a terminal box (120), a compensator (130), an electronics compartment (140), a protective cover (150), and a sonar; wherein, the terminal box (120) is connected to the umbilical cable (300) and has a built-in transformer to transform the high voltage in the umbilical cable (300) and connect and process various underwater electrical signals; the compensator (130) is used to compensate for hydraulic oil pressure underwater and serves as an oil tank; the electronics compartment (140) has various electrical components built-in for receiving and processing underwater signals; multiple protective covers (150) are set on the outside of the main frame (100), and a sonar is installed inside the protective cover (150).

7. The underwater trenching and cable laying device according to claim 1, characterized in that, The inner wall of the inner sheath (410) is shaped as a two-way outward flared horn, with radially protruding snap-fit ​​flanges (411) at both ends that snap into the inner wall of the outer sheath (420). The outer sheath (420) has arc-shaped end faces at both ends, and adjacent outer sheaths (420) are bent into fit. A roller is provided on the first connecting part (510), and the roller is in rolling fit with the umbilical cable (300).

8. An underwater trenching and cable laying system, characterized in that, include: The underwater trenching and cable laying device (1000) as described in any one of claims 1 to 7. Mother ship (2000) is used to provide equipment installation, ship power and positioning; The umbilical cable (300) connects to the surface power supply and control system, providing power and control signals to the operating system; The control cabin (2010) is used to operate the control area and is electrically connected to the umbilical cable (300); The power distribution compartment (2020) is electrically connected to the ship's power supply and umbilical cable (300), providing power and frequency conversion control for the underwater controlled flow trencher; The crane (2030) is connected to the lifting device (110) of the underwater trenching and cable laying device (1000) by a steel wire rope. An umbilical cable winch (2040) is used to store the umbilical cable (300), connect to the underwater trenching and cable laying device (1000), and control the length and tension of the umbilical cable (300); At least two wire rope winches (2050) are respectively set on both sides of the umbilical cable winch (2040) and connected to both sides of the underwater trenching and cable laying device (1000) by wire rope. The attitude of the underwater trenching and cable laying device (1000) is adjusted by controlling the length and tension of the wire rope. The hydraulic power unit (2060) provides hydraulic power to the wire rope winch (2050) and the umbilical cable winch (2040).

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