A cable float underwater recovery device and recovery method

Abstract

This invention discloses an underwater recovery device and method for cable floats, applicable to flexible cables and the cable floats to be recovered thereon. It includes a recovery mechanism and a dismantling mechanism for cutting the cable float's binding straps. The dismantling mechanism cuts the binding straps of the cable float, causing the cable float to detach from the flexible cable and float freely within a first frame. This invention uses a first frame with an open bottom to capture the cable float underwater. The first frame, carrying the cable float, sits within a second frame underwater, sealing the bottom of the first frame. A crane then lifts the second frame to the deck, achieving recovery of the cable float without the risk of it falling. This method requires less material, has low manufacturing costs, and has significant potential for widespread application. It is not only suitable for flexible risers but can also be applied to the dismantling and recovery of cable floats for dynamic cables, umbilical cables, etc., significantly improving operational efficiency and reducing operational risks.

Description

Technical Field

[0001] This application relates to the field of marine oil engineering technology, and in particular to an underwater recovery device for a cable float and a recovery method thereof. Background Technology

[0002] Before a Floating Production Storage and Offloading (FPSO) vessel is released, the flexible riser typically needs to be temporarily wet-stored on the seabed. The float is then recovered after the FPSO is released. The flexible riser consists of a flexible riser connector, a bend limiter short connector, a bend limiter, a float, and the riser body.

[0003] Currently, the conventional method for recovering deep-water flexible riser floats in China requires the use of a cable laying system to retrieve the flexible hose to the deck, where the float is then dismantled. When using a cable laying system to recover the flexible riser to the deck, the flexible riser connector and bend limiter must first be retrieved to the deck. Furthermore, the flexible riser connector and bend limiter must be wound into a drum via a tensioner and guide wheel. Storing bend limiters, which are approximately 7 meters long, on the drum is quite difficult. Cutting the bend limiter online poses a risk of damaging the flexible riser. Additionally, it is uncertain whether the performance parameters of the old flexible riser still meet the clamping requirements of the tensioner. This results in low recovery efficiency and high recovery costs. Summary of the Invention

[0004] The technical problem to be further solved by the present invention is to provide an underwater recovery device for cable floats that consumes less material, has low manufacturing cost, has promotional value and potential, and can also be applied to the dismantling and recovery of cable floats such as dynamic cables and umbilical cables, thereby improving the efficiency of recovery operations.

[0005] The technical solution provided by this invention is an underwater recovery device for a flexible cable float, applicable to a flexible cable and a cable float to be recovered thereon. The device includes a recovery mechanism and a dismantling mechanism for cutting the cable float's binding straps. The recovery mechanism includes a first frame for recovering the cable float and a second frame to prevent the cable float from falling during recovery. The first frame covers the cable float from all sides, and the top of both the first and second frames is equipped with rigging that works with a crane.

[0006] Furthermore, in the underwater recovery device for the cable float, preferably, openings are provided on the opposite side walls of the first frame, the width of the openings being greater than the outer diameter of the flexible cable, and the width of the openings being less than half the radius of the cable float.

[0007] Furthermore, in the underwater recovery device for the cable float, preferably, a first inlet is provided at the bottom of the first frame, and the first inlet is used for the cable float to float into the interior of the first frame; or / and a second inlet is provided at the top of the second frame, and the first frame is located inside the second frame by the second inlet;

[0008] In addition, the top of the second frame is provided with a guide mechanism that cooperates with the first frame, the guide mechanism being used to guide the first frame to sit freely within the second frame.

[0009] Furthermore, in the underwater recovery device for the cable float, the dismantling mechanism preferably includes a robotic arm and a drive element for driving the robotic arm. The drive element is connected to two robotic arms, and the front ends of the two robotic arms are respectively provided with a hydraulic shear element and a hook-unhooking gripper element.

[0010] The technical problem to be solved by this invention is to provide a safe, economical and efficient solution to the problem of underwater recovery of large-size cable floats. This method is not affected by the resources of large ships, and while ensuring the safety of the recovery operation, it also improves the efficiency of offshore operations. It is economical and breaks through the traditional method of recovering cables by relying on horizontal and vertical laying systems. This method is a low-cost underwater recovery method for cable floats.

[0011] The technical solution provided by this invention is a method for underwater recovery of a cable float, comprising the following steps: S1, placing the first frame inside the second frame from the top of the second frame, and lowering the second frame with the first frame to the seabed using a crane;

[0012] S2, the dismantling mechanism completes the unhooking of the crane hook and the second frame sling underwater, and then the dismantling mechanism completes the connection of the crane hook and the first frame lifting sling;

[0013] S3, the crane lifts the first frame away from the second frame, and then the first frame covers the cable float cover inside, while the flexible cable is horizontally inserted and secured in the symmetrical wall of the first frame;

[0014] S4, the dismantling mechanism cuts the binding strap of the cable float to cut it, so that the cable float is separated from the flexible cable and floats freely inside the first frame.

[0015] S5, the crane lifts the first frame away from the flexible cable and guides the first frame, carrying the cable float, into the second frame through the guide mechanism. The dismantling mechanism removes the rigging between the crane hook and the first frame, and then the dismantling mechanism grabs the crane hook and hooks it onto the rigging of the second frame.

[0016] S6, the crane retrieves the second frame and carries the first frame to the deck. The staff removes the cable floats from the first frame and stores them in the deck storage box.

[0017] Furthermore, in the underwater recovery method of the cable float, preferably in step S1, the first frame is located within the second frame through a second inlet opened at the top of the second frame.

[0018] Furthermore, in the underwater recovery method of the cable float, preferably in step S2, the robotic arm drives the unhooking gripper element to underwater clamp the crane hook to detach from the second frame, and the robotic arm drives the unhooking gripper element to clamp the crane hook to hook onto the first frame.

[0019] Furthermore, in the underwater recovery method of the cable float, preferably in step S3, the first frame covers the cable float inside through the first inlet opened at the bottom, and the flexible cable is inserted and secured in the opening opened in the symmetrical wall of the first frame.

[0020] The width of the opening in S3 is greater than the outer diameter of the flexible cable, and the width of the opening is less than half the radius of the cable float.

[0021] The cable floats are retrieved sequentially from the top to the bottom of the flexible cable.

[0022] Furthermore, in the underwater recovery method of the cable float, preferably in step S4, a robotic arm drives a hydraulic shearing element to cut the binding straps of the cable float.

[0023] After the robotic arm drives the hydraulic shearing element to cut the cable float binding tape, if the cable float is stuck and cannot float freely, the robotic arm needs to drive the unhooking gripper element to carry the pry bar to push the cable float away from its original position.

[0024] The robotic arm drives the hydraulic shearing element to cut the flexible tubing at both ends of the cable float, causing the cable float to detach from the flexible tubing and float freely inside the first frame.

[0025] Furthermore, in the underwater recovery method of the cable float, preferably in step S5, the robotic arm drives the unhooking gripper element to clamp the rigging that has detached the crane hook from the first frame, and the robotic arm drives the unhooking gripper element to grab the crane hook and hook it to the second frame.

[0026] Compared with the prior art, the beneficial effects of the present invention are:

[0027] This invention relates to an underwater cable float recovery device. A first frame with an open bottom captures the cable float underwater, preventing it from floating freely after the buoy's binding straps are cut. The first frame, carrying the cable float, sits within a second frame, sealing the bottom of the first frame to prevent the float from falling out during recovery. A crane then lifts the second frame to the deck, achieving recovery of the cable float without the risk of it falling out. This device requires minimal materials, has low manufacturing costs, and has significant potential for widespread application. It is suitable not only for flexible risers but also for the dismantling and recovery of cable floats for dynamic cables, umbilical cables, etc., significantly improving operational efficiency and reducing operational risks.

[0028] This invention provides a method for underwater recovery of cable floats. A first frame with an open bottom captures the cable float underwater, preventing it from floating freely after the lashing straps are cut. The first frame, carrying the cable float, is then placed within a second frame, sealing the bottom of the first frame to prevent the float from falling out during recovery. A crane then lifts the second frame onto the deck, achieving recovery of the cable float without the risk of it falling out. This method safely, economically, and efficiently solves the problem of underwater recovery of large-sized cable floats, is unaffected by the resources of large vessels, and improves operational efficiency while ensuring safety. It offers excellent economic benefits, breaking through the traditional methods of recovering cables using horizontal and vertical laying systems, thus reducing costs and increasing efficiency. Attached Figure Description

[0029] Figure 1 This is a first-view structural diagram of the first frame and the second frame of Embodiment 1 of the present invention.

[0030] Figure 2 This is a schematic diagram of the structure of the first frame of Embodiment 1 of the present invention.

[0031] Figure 3 This is a schematic diagram of the first frame and flexible cable in Embodiment 2 of the present invention.

[0032] Figure 4 This is a schematic diagram of the structure of the first frame and the cable float in Embodiment 2 of the present invention.

[0033] Figure 5 This is a schematic diagram of the second frame structure of Embodiment 2 of the present invention.

[0034] Explanation of the labels in the diagram:

[0035] 1. First frame; 2. Second frame; 3. Flexible cable; 4. Cable float; 5. Opening; 6. Guiding mechanism; 7. Rigging. Detailed Implementation

[0036] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0037] Example 1, by Figures 1 to 5 The present invention discloses an underwater recovery device for a flexible cable 3 and a cable 4 to be recovered thereon, including a recovery mechanism and a disassembly mechanism for cutting the binding straps of the cable 4.

[0038] The recovery mechanism includes a first frame 1 for recovering the cable float 4 and a second frame 2 to prevent the cable float 4 from falling during recovery. The first frame 1 covers the cable float 4, and the top of both the first frame 1 and the second frame 2 is equipped with rigging 7 that works with the crane.

[0039] Depend on Figures 1 to 2 Preferably, the crane is located on the ship's deck, and the rigging 7 is made of steel cables, ropes, etc., without limitation on the material. There are four steel cables, one end of which is installed at the four corners of the top of the first frame 1 or the second frame 2, and the other ends of the steel cables are connected to each other to facilitate the crane hook to hook onto the steel cables. The crane uses the steel cables to lift the first frame 1 and the second frame 2. The rigging 7 is installed at the four corners of the top of the first frame 1 and / or the second frame 2 by welding, binding, bolting, etc.

[0040] Alternatively, the top of the first frame 1 or the second frame 2 may not be equipped with rigging 7. The crane may have four hooks. When the crane lifts the first frame 1 or the second frame 2, the four hooks may be hooked at the four corners of the top of the first frame 1 or the second frame 2, or there may be lifting rings at the four corners of the top of the first frame 1 and the second frame 2. The hooks may be hooked onto the lifting rings to complete the lifting operation.

[0041] Depend on Figures 3 to 5 It is given that the two opposite side walls of the first frame 1 are provided with openings 5, the width of the openings 5 ​​is greater than the outer diameter of the flexible cable 3, and the width of the openings 5 ​​is less than half the radius of the cable float 4.

[0042] The bottom of the first frame 1 is provided with a first inlet, and the first inlet is used for the cable float 4 to float into the interior of the first frame 1; or / the top of the second frame 2 is provided with a second inlet, and the first frame 1 is located in the second frame 2 by the second inlet.

[0043] Preferably, the width of the opening 5 is greater than the outer diameter of the flexible cable 3, which facilitates the placement of the first frame 1. The first inlet and the two openings facilitate the first frame 1 to cover the flexible cable 3. In addition, the flexible cable 3 is located inside the opening 5, which prevents the first frame 1 from pressing on the flexible cable 3, prevents the first frame 1 from being in an inclined state, prevents gaps between the first frame 1 and the seabed, and prevents the cable float 4 from drifting away from the bottom gap. Furthermore, the cable float 4 floats inside the first frame 1, and the width of the opening 5 is less than the radius of the cable float 4, which prevents the cable float 4 inside the first frame 1 from drifting away from the opening 5 after being cut off.

[0044] Depend on Figures 1 to 2 Furthermore, the top of the second frame 2 is provided with a guide mechanism 6 that cooperates with the first frame 1. The guide mechanism 6 is used to guide the first frame 1 to freely sit inside the second frame 2.

[0045] Preferably, the guide mechanism 6 consists of two guide posts located on both sides of the top of the second frame 2, with the tops of the two guide posts tilted outwards. When the first frame 1 is placed inside the second frame 2, the side wall at the bottom of the first frame 1 will first contact the two guide posts. Through the limiting and guiding of the two guide posts, the first frame 1 will eventually enter the second inlet and sit inside the second frame 2.

[0046] Alternatively, four guide pillars can be installed. The four guide pillars are installed on the four sides of the top of the second frame 2, and the two symmetrical guide pillars are in an inverted V-shape. The four guide pillars are inclined outward, similar to a funnel structure. The larger opening of the inverted V-shape facilitates the entry of the first frame 1. The opening of the inverted V-shape gradually narrows, slowly guiding the first frame 1 into the second inlet and settling into the second frame 2.

[0047] The dismantling mechanism includes a robotic arm and a drive element for driving the robotic arm's movements. The drive element is connected to two robotic arms, and the front ends of the two robotic arms are respectively equipped with a hydraulic shearing element and a hook-unhooking gripper element. Preferably, the hydraulic shearing element is a hydraulic shear, a cutting blade, a cutting wheel, or other cutting tools. The hydraulic shearing element cuts the cable float 4 binding straps or flexible cable 3 from outside the first frame 1.

[0048] Example 2, by Figures 1 to 5 The present invention discloses an underwater recovery method for a cable float, comprising the following steps: S1, placing a first frame 1 from the top of a second frame 2 and placing it inside the second frame 2, and lowering the second frame 2 with the first frame 1 to the seabed by a crane. Preferably, in S1, the first frame 1 is placed inside the second frame 2 through a second inlet opened at the top of the second frame 2.

[0049] Specifically, when the ship is anchored near the sea level of the flexible cable 3, the crane on the ship's deck lifts the first frame 1 and places it into the second frame 2 through the second inlet. Then, the staff manually removes the crane hook from the rigging 7 of the first frame 1 and hooks the hook onto the rigging 7 of the second frame 2. Finally, the crane lifts the second frame 2 and lowers it to the seabed next to the flexible cable 3.

[0050] S2, the disassembly mechanism completes the underwater unhooking of the crane hook from the sling 7 of the second frame 2, and then the disassembly mechanism completes the connection of the crane hook to the hoisting sling 7 of the first frame 1; preferably, in S2, the robotic arm drives the unhooking gripper element to grip the crane hook underwater and detach it from the sling 7 of the second frame 2, and the robotic arm drives the unhooking gripper element to grip the crane hook and hook it back to the sling 7 of the first frame 1.

[0051] Specifically, the dismantling mechanism is an underwater robot, and the driving element is the core of the underwater robot. The unhooking gripper element consists of four mechanical grippers, or three or five mechanical grippers, depending on the requirements. The optimal choice is four mechanical grippers to grasp and move the crane hook. More specifically, another crane on the ship's deck lowers the underwater robot to the side of the second frame 2. The driving element includes an underwater camera and a sensing system. The underwater camera identifies the position of the rigging 7 on the second frame 2, and the sensing system plans the unhooking path. The robotic arm controls the unhooking gripper element to clamp onto the crane hook and remove it from the rigging 7 on the second frame 2. Then, the sensing system plans the hooking path, and the robotic arm drives the unhooking gripper element to clamp onto the crane hook and hook it onto the rigging 7 on the first frame 1.

[0052] The preferred rigging 7 is steel cable, rope, etc., and the material is not limited. Steel cable is preferred as needed, and three, four, or five steel cables are provided according to the requirements. The optimal rigging 7 is four steel cables. One end of the four steel cables is installed at the four corners of the top of the first frame 1 or the second frame 2, and the other end of the steel cables are connected to each other to facilitate the hook of the crane to hook onto the steel cables.

[0053] Depend on Figures 3 to 5 As given, in S3, the crane lifts the first frame 1 away from the second frame 2, and then the first frame 1 covers the cable float 4 inside, while the flexible cable 3 is horizontally inserted and secured in the symmetrical wall of the first frame 1; in the preferred S3, the first frame 1 covers the cable float 4 inside through the first inlet opened at the bottom, while the flexible cable 3 is horizontally inserted and secured in the opening 5 opened in the symmetrical wall of the first frame 1.

[0054] Specifically, the crane lifts the first frame 1 away from the second frame 2, and then attaches the bottom of the first frame 1 to the outside of the cable float 4. The first frame 1 captures the cable float 4. The flexible cables 3 at both ends of the cable float 4 pass through the openings 5 ​​on the opposite side walls of the first frame 1, completely enclosing the cable float 4 inside the first frame 1.

[0055] In the preferred embodiment of S3, the width of the opening 5 in S3 is greater than the outer diameter of the flexible cable 3, and the width of the opening 5 is less than half the radius of the cable float 4; in an even more preferred embodiment of S3, the cable float 4 is retrieved sequentially from the top end to the tail end of the flexible cable 3.

[0056] Specifically, the width of the opening 5 is greater than the outer diameter of the flexible cable 3, which facilitates the placement of the first frame 1. The first inlet and the two openings 5 ​​facilitate the first frame 1 to cover the flexible cable 3. In addition, the flexible cable 3 is located inside the opening 5 to prevent the first frame 1 from pressing on the flexible cable 3, to prevent the first frame 1 from being in an inclined state, to prevent gaps between the first frame 1 and the seabed, and to prevent the cable float 4 from drifting away from the gaps.

[0057] S4, the disassembly mechanism cuts the binding tape of the cable float 4 to detach the cable float 4 from the flexible cable 3 and allow it to float freely inside the first frame 1; preferably, in S4, the robotic arm drives the hydraulic shear element to cut the binding tape of the cable float 4; preferably, in S4, the hydraulic shear element is a hydraulic shear, a cutting knife, a cutting wheel, or other cutting tools.

[0058] Specifically, the flexible cable 3 is laid on the seabed or floats in the ocean, the cable float 4 floats in the ocean and is located directly above the flexible cable 3. The cable float 4 is connected to the flexible cable 3 by a binding strap. The underwater camera identifies the position of the binding strap, the sensing system plans the unhooking path, and the robotic arm drives the hydraulic shearing element to cut the binding strap.

[0059] In the preferred S4, another recovery method is to wrap and fix the cable float 4 around the flexible cable 3. In this case, the cable float 4 and the flexible cable 3 are recovered together. The robotic arm drives the hydraulic shear element to cut the flexible cable 3 at both ends of the cable float 4, so that the cable float 4 is separated from the flexible cable 3 and floats freely inside the first frame 1. The cable float 4 carries a small part of the flexible cable 3 and floats inside the first frame 1 for recovery.

[0060] More specifically, the hydraulic shears consist of two blades and a hydraulic device. The hydraulic device drives the two blades to move towards each other, thereby cutting the cable ties.

[0061] In the preferred S4, after the robotic arm drives the hydraulic shearing element to cut the cable float 4 binding tape, if the cable float 4 is stuck and cannot float freely, the robotic arm needs to drive the unhooking gripper element to carry the pry bar to push the cable float 4 away from its original position.

[0062] Specifically, the cut may cause the flexible cable 3 and the cable float 4 to get stuck together. In this case, the hook-and-grip element needs to be used to use a pry bar to push the cable float 4 away from the flexible cable 3 so that it can float freely within the first frame 1. Alternatively, after the cut, the cable float 4 may be entangled in seaweed and unable to float freely. In this case, the cable float 4 needs to be pushed to get rid of the seaweed.

[0063] Depend on Figures 1 to 2 As given, in step S5, the crane lifts the first frame 1 away from the flexible cable 3, and guides the first frame 1, carrying the cable float 4, into the second frame 2 by the guide mechanism. The dismantling mechanism removes the rigging 7 from the crane hook and the first frame 1, and then the dismantling mechanism grabs the crane hook and hooks it onto the rigging 7 of the second frame 2. Preferably, in step S5, the robotic arm drives the unhooking gripper element to clamp the crane hook and disengage it from the rigging 7 of the first frame 1, and the robotic arm drives the unhooking gripper element to grab the crane hook and hook it onto the rigging 7 of the second frame 2.

[0064] Specifically, the underwater camera identifies the position of the second frame 2, and the operator controls the crane to lift the first frame 1 and move it into the second frame 2. During the lifting process, because the cable float 4 has a floating property, the cable float 4 will move along with the first frame 1. Furthermore, when the first frame 1 is placed inside the second frame 2, the bottom of the first frame 1 first contacts the guide mechanism. Under the guidance of the guide mechanism, the first frame 1 corresponds to the second inlet, so that the first frame 1 is placed inside the second frame 2 through the second inlet.

[0065] Depend on Figures 4 to 5 More specifically, the guide mechanism 6 consists of two guide posts located on both sides of the top of the second frame 2, with the tops of the two guide posts tilted outwards. When the first frame 1 is placed inside the second frame 2, the side wall at the bottom of the first frame 1 will first contact the two guide posts. Through the limiting and guiding of the two guide posts, the first frame 1 will finally enter the second inlet and settle into the second frame 2.

[0066] Alternatively, four guide pillars are installed on the four sides of the top of the second frame 2, and the two symmetrical guide pillars form an inverted V-shape. The larger opening of the inverted V-shape facilitates the entry of the first frame 1, and the opening of the inverted V-shape gradually narrows, slowly guiding the first frame 1 into the second inlet and settling into the second frame 2.

[0067] S6, the crane retrieves the second frame 2, carrying the first frame 1 to the deck. The staff removes the cable float 4 from the first frame 1 and stores it in the deck storage box.

[0068] Specifically, the underwater camera identifies the position of the rigging 7 of the first frame 1, the sensor system plans the unhooking path, and the unhooking gripper element clamps onto the crane hook to remove it from the rigging 7 of the first frame 1. Then, the sensor system plans the hooking path, the unhooking gripper element clamps onto the crane hook and hooks it onto the rigging 7 of the second frame 2, and the operators control the crane to lift the second frame 2, carrying the first frame 1 and the cable float 4 to the ship's deck. Then, the workers or the crane remove the first frame 1 from the second frame 2. Finally, the cable float 4 inside the second frame 2 is removed and placed in a storage box to complete the recovery.

[0069] The beneficial effects of the first frame 1, the second frame 2, and the rigging 7 are as follows: The underwater recovery device for cable floats of the present invention captures the cable float 4 underwater through the first frame 1 with a bottom opening, preventing the cable float 4 from floating freely after the binding strap is cut. Underwater, the first frame 1 carries the cable float 4 and sits in the second frame 2, thus sealing the bottom of the first frame 1 and preventing the cable float 4 from falling out of the first frame 1 during the recovery process. Then, the crane lifts the second frame 2 to the deck, achieving the recovery of the cable float 4 without the risk of falling. It requires less material and has low manufacturing cost, and has great promotional value and potential. It is not only suitable for flexible cables 3, but can also be applied to the dismantling and recovery of cable floats 4 of dynamic cables, umbilical cables, etc., which can greatly improve the efficiency of operation and reduce the risk of operation.

[0070] The present invention provides a method for underwater recovery of cable floats. A first frame 1 with a bottom opening captures the cable float 4 underwater, preventing it from floating freely after the binding straps are cut. The first frame 1, carrying the cable float 4, is then placed within a second frame 2, effectively sealing the bottom of the first frame 1 to prevent the cable float 4 from falling out during recovery. A crane then lifts the second frame 2 onto the deck, achieving recovery of the cable float 4 without the risk of it falling. This method safely, economically, and efficiently solves the problem of underwater recovery of large-sized cable floats 4, is unaffected by the resources of large vessels, and improves the efficiency of offshore operations while ensuring the safety of the recovery operation. It is economically sound and breaks through the traditional methods of recovering cables using horizontal and vertical laying systems, achieving cost reduction and efficiency improvement.

[0071] It is understood that the above embodiments only illustrate preferred embodiments of the present invention, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can freely combine the above technical features without departing from the concept of the present invention, and can also make several modifications and improvements, all of which fall within the protection scope of the present invention. Therefore, all equivalent transformations and modifications made with respect to the scope of the claims of the present invention should fall within the scope of the claims of the present invention.

Claims

1. A method for underwater recovery of a cable float, applied to a flexible cable (3) and a cable float (4) thereon that needs to be recovered, characterized in that, An underwater recovery device for cable floats is adopted, which includes a recovery mechanism and a dismantling mechanism for cutting the cable float (4) binding straps; The recovery mechanism includes a first frame (1) for recovering the cable float (4) and a second frame (2) to prevent the cable float (4) from falling during recovery. The first frame (1) covers the cable float (4) around its perimeter. The top of both the first frame (1) and the second frame (2) is equipped with rigging (7) that works in conjunction with the crane. The method includes the following steps: S1, placing the first frame (1) on top of the second frame (2) inside the second frame (2), and lowering the second frame (2) with the first frame (1) to the seabed by a crane; S2, the dismantling mechanism completes the unhooking of the crane hook and the second frame (2) sling (7) underwater, and then the dismantling mechanism completes the connection of the crane hook and the first frame (1) hoisting sling (7); S3, the crane lifts the first frame (1) away from the second frame (2), and then the first frame (1) covers the cable float (4) inside, and the flexible cable (3) is horizontally inserted and clamped in the symmetrical wall of the first frame (1); S4, the dismantling mechanism cuts the binding strap of the cable float (4) to make the cable float (4) detach from the flexible cable (3) and float freely inside the first frame (1); S5, the crane lifts the first frame (1) away from the flexible cable (3), and guides the first frame (1) with the cable float (4) into the second frame (2) by the guide mechanism. The dismantling mechanism removes the rigging (7) between the crane hook and the first frame (1), and then the dismantling mechanism grabs the crane hook and hooks it to the rigging (7) of the second frame (2). S6, the crane retrieves the second frame (2) and carries the first frame (1) to the deck. The staff removes the cable float (4) inside the first frame (1) and stores it in the deck storage box.

2. The underwater recovery method for a cable float according to claim 1, characterized in that, The first frame (1) has openings (5) on its opposite side walls. The width of the openings (5) is greater than the outer diameter of the flexible cable (3), and the width of the openings (5) is less than half the radius of the cable float (4).

3. The underwater recovery method for a cable float according to claim 2, characterized in that, The bottom of the first frame (1) is provided with a first inlet, and the first inlet is used for the cable float (4) to float into the interior of the first frame (1); or / and the top of the second frame (2) is provided with a second inlet, and the first frame (1) is located in the second frame (2) by the second inlet; In addition, the top of the second frame (2) is provided with a guide mechanism (6) that cooperates with the first frame (1), the guide mechanism (6) is used to guide the first frame (1) to sit freely in the second frame (2).

4. The underwater recovery method for a cable float according to claim 1, characterized in that, The disassembly mechanism includes a robotic arm and a drive element for driving the robotic arm to move. The drive element is connected to two robotic arms, and the front ends of the two robotic arms are respectively provided with a hydraulic shear element and a hook-unhooking gripper element.

5. The underwater recovery method for a cable float according to claim 3, characterized in that, In S1, the first frame (1) is located within the second frame (2) by a second inlet opened at the top of the second frame (2).

6. The underwater recovery method for a cable float according to claim 4, characterized in that, In S2, the robotic arm drives the unhooking gripper element to underwater clamp the crane hook to detach from the second frame (2) and the robotic arm drives the unhooking gripper element to clamp the crane hook to the first frame (1) and the hook to hook the first frame (1) and hook the first frame (1) and hook the first frame (1) and hook the first frame (2 ...3) and hook the first frame (4) and hook the first frame (5) and hook the first frame (6) and hook the first frame (7).

7. The underwater recovery method for a cable float according to claim 3, characterized in that, In S3, the first frame (1) covers the cable float (4) inside the first inlet opened at the bottom, and the flexible cable (3) is inserted through the opening (5) opened on the symmetrical wall of the first frame (1). The width of the opening (5) in S3 is greater than the outer diameter of the flexible cable (3), and the width of the opening (5) is less than half the radius of the cable float (4). The cable float (4) is retrieved sequentially from the top to the bottom of the flexible cable (3).

8. The underwater recovery method for a cable float according to claim 4, characterized in that, In S4, the robotic arm drives the hydraulic shearing element to cut the binding strap of the cable float (4); After the robotic arm drives the hydraulic shearing element to cut the cable float (4) binding strap, if the cable float (4) is stuck and cannot float freely, the robotic arm needs to drive the hook-unhooking gripper element to carry the pry bar to push the cable float (4) away from its original position. The robotic arm drives the hydraulic shearing element to cut the flexible cable (3) at both ends of the cable float (4), so that the cable float (4) is separated from the flexible cable (3) and floats freely inside the first frame (1).

9. A method for underwater recovery of a cable float according to claim 4, characterized in that, In S5, the robotic arm drives the unhooking gripper element to clamp the crane hook and disengage the rigging (7) from the first frame (1), and the robotic arm drives the unhooking gripper element to grab the crane hook and hook it to the second frame (2) rigging (7).

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