Large-scale culture net cage offshore towing and multi-ship cooperative position control method

Abstract

The invention relates to a large-scale culture net cage offshore towing and multi-ship cooperative position control method. The method comprises the steps that S1, a net cage towing and in-position scheme is formulated; s2, net cage pulling preparation; s3, towing in the harbor; a three-purpose tug and a harbor tug are adopted, and the three-purpose tug and the harbor tug are matched with each other to drag the net cage to leave the wharf and drive into a harbor departure channel; s4, towing outside the harbor; a three-purpose tug and a harbor are adopted as tugs for towing, and according to the course and the voyage, the safe navigation speed is determined, and a safe water area is entered; s5, net cage entrance; and two three-purpose tugs, a harbor tug, a working boat and an engineering boat are cooperated to carry out net cage position control and are connected with four pre-laid anchor chains, so that large net cage towing and cooperative position control mounting operation are completed. The marine towing and in-place mounting device can safely and effectively carry out marine towing and in-place mounting operation on the large-scale aquaculture net cage, and effectively fills the blank of the marine towing and in-place mounting technology of the large-scale aquaculture net cage.

Description

Technical Field

[0001] The present invention relates to the technical field of ship engineering, and in particular to a method for towing a large-scale aquaculture cage at sea and for coordinated positioning of multiple ships. Background Art

[0002] Marine ranching is a new model of marine economy and a new form of marine industry. In 2023, aquaculture production will be 58.12 million tons, up 4.4% from 2022, with a net increase of 2.5 million tons. As China's aquaculture production continues to shift towards industrialization and intensiveness in recent years, deep-sea gravity cages have emerged in many places in China. Cage installation is a key project in the construction of marine ranches, but there are many technical difficulties in the process.

[0003] The cage is a regular hexagonal column-stabilized frame structure with buoys symmetrically arranged on the left and right sides of the base. After the construction is completed in the shipyard, it needs to be transferred to the designated sea area for installation. During the construction process, the cage is towed at sea to the breeding site. In order to ensure the safety and reliability of the cage structure under harsh working conditions, it needs to be fixed by anchoring. There are many operational difficulties and safety risks in the process of towing and positioning the cage, and any carelessness will cause major losses. The towing and positioning of the cage at sea is different from that of ships or offshore platforms for ship engineering personnel, and the industry lacks more mature towing and positioning technology. Summary of the invention

[0004] In view of the above problems, the purpose of the present invention is to provide a method for towing large-scale aquaculture cages at sea and coordinated positioning control of multiple ships. By using an engineering ship, two three-purpose tugboats, a harbor tugboat and a work boat to respectively carry out sea towing and coordinated control of the cages in place, the technical effect of safe and effective sea towing and installation of large-scale aquaculture cages is achieved, effectively filling the technical gap in sea towing of large-scale aquaculture cages and coordinated installation of multiple ships.

[0005] The technical solution adopted by the present invention is as follows:

[0006] The present invention proposes a method for towing a large-scale aquaculture cage at sea and coordinating the positions of multiple vessels, comprising the following steps:

[0007] S1. Develop a plan for cage towing and positioning;

[0008] S2, Preparation for lifting the cage;

[0009] The net cage needs to be prepared with mooring nylon cable, dragon beard cable and towing cable in advance. The overall height of the net cage is relatively high, and it is transported by a three-purpose tugboat equipped with sufficient special equipment for towing and the triangle plate, shackle and main towing cable required for conventional towing;

[0010] According to the construction plan, an engineering vessel and a multi-purpose tugboat II will complete the pre-laying of four anchor chains in the designated sea area, so that the cages can be put in place and installed as soon as possible after arriving at the designated sea area;

[0011] S3, towing in the port;

[0012] The three-purpose tugboat I and the port tugboat are connected to the net cages through towing equipment respectively, and the three-purpose tugboat and the port tugboat cooperate with each other to tow the net cages away from the wharf and enter the port channel;

[0013] S4, towing outside the port;

[0014] The three-purpose tugboat I tows the cages and assists with the harbor tugboat hanging at the rear of the cages. During the towing, the tugboat, towing equipment and the floating state of the cages are monitored. According to the course and distance, the safe navigation speed is determined and the cages are entered into safe waters.

[0015] S5, cage entry;

[0016] Before the cages enter the site, the engineering vessel, in cooperation with the three-purpose tugboat II, completes the anchoring of its own six positioning anchors and the pre-laying of four anchor chains for the cages, and waits near the upwind direction of the cages to be towed into the site;

[0017] After the cages enter the site, they gradually approach the engineering ship. When the three-purpose tugboat I tows the cages and approaches the engineering ship, the port tugboat tows the cages close to the stern of the engineering ship to prepare the cable, that is, the cages are towed at this time; the three-purpose tugboat II and a working boat are on standby near the cages, ready to assist and respond to emergencies at any time;

[0018] After the cage is towed over, it is towed by the harbor tugboat to a distance from the stern of the engineering ship within the range of the cable. At this time, the mooring cable of the cage is transported to the engineering ship by the workboat. The engineering ship cooperates with the harbor tugboat and the three-purpose tugboat I to gradually tighten the four mooring cables to a suitable distance. After the cage is moored to the engineering ship, the three-purpose tugboat II picks up the four anchor chains laid in advance respectively, and cooperates with the engineering ship to connect the mooring cable of the cage with the pre-laid anchor chain and the buoy. During this process, the three-purpose tugboat I maintains a certain tension to tighten the cage, and cooperates with the mooring cable of the engineering ship to control the position of the cage to prevent the displacement of the cage. The engineering ship adjusts the length of the six anchor cables and the positioning anchor through the three-purpose tugboat I to shift the engineering ship and the cage to the vicinity of the end of the pre-laid anchor chain, and cooperates with the three-purpose tugboat II to connect the mooring chain and the pre-laid anchor chain and perform tension test, complete the connection of the four pre-laid anchor chains and the mooring cable of the cage and perform tension test. After meeting the requirements, the installation work is completed.

[0019] Furthermore, in step S1, the solution includes accurately obtaining various parameters of the cage, and determining the types and quantities of vessels in the towing and positioning stages.

[0020] Furthermore, in step S2, the special equipment for cable-lifting includes a cable-lifting rope and a cable-lifting gun.

[0021] Furthermore, in step S3, the three-purpose tugboat I tows the net cage by connecting the mooring nylon cable, the dragon's beard cable, the short cable, the triangle plate, the short cable and the main tow cable, and the port tugboat hangs the stern of the net cage by the nylon cable to cooperate in controlling the navigation and buoyancy of the net cage.

[0022] Furthermore, in step S4, a steel cable is connected to the temporary anchor chain fastening point of the net box, and the other end is fastened to the root of the eye plate by a steel wire to control the movement of the anchor chain. The rest of the anchor chain is laid on the three-purpose tugboat I and the spare anchor, short rope, buoy and nylon cable are connected.

[0023] Furthermore, in step S4, after entering the safe waters, the length of the towline is adjusted in real time according to weather and sea conditions, hydrology, traffic density in the navigation area, water depth and draft, and the amount of towing force used.

[0024] Compared with the prior art, the present invention has the following beneficial effects:

[0025] 1. The present invention includes the technical points of towing in ports, outside ports and safe waters and the method of emergency anchoring of cages, which greatly improves the safety of towing large-scale aquaculture cages and provides effective protection for the offshore towing operations of large-scale aquaculture cages.

[0026] 2. Before the cages leave the port and go out to sea, the four anchor chains of the cages have been pre-laid, and the engineering vessel has made preparations for mooring the cages on the upstream side of two anchor chains, which has gained a time window to reduce the incomplete controllable state of the cages at sea and avoid missing the best time for the cages to enter and connect.

[0027] 3. After the cages arrived near the offshore positioning point, the coordination of an engineering vessel, two three-purpose tugboats, a harbor tugboat and a work boat greatly improved the efficiency of positioning and installation of the cages, indicating that the positioning construction plan for this large-scale aquaculture cage has technical characteristics such as clear division of labor and coordination. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 Schematic diagram of the pre-laying effect of the cage anchor chain in an embodiment of the present invention;

[0029] Figure 2 Schematic diagram of cage towing in an embodiment of the present invention;

[0030] Figure 3 Schematic diagram of temporary anchoring of a cage in an embodiment of the present invention;

[0031] Figure 4 This is a schematic diagram of the cage entry in an embodiment of the present invention;

[0032] Figure 5 Schematic diagram of the cage turning 90° in the embodiment of the present invention;

[0033] Figure 6 1 is a schematic diagram of the connection of the anchor chain (C11 end) in an embodiment of the present invention;

[0034] Figure 7 It is a schematic diagram of the connection between the net cage and the engineering ship with cables in an embodiment of the present invention. DETAILED DESCRIPTION

[0035] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0036] See attached Figure 1 The present invention proposes a method for towing a large-scale aquaculture cage at sea and coordinating the position of multiple vessels. The specific implementation process is as follows:

[0037] S1. Develop a plan for cage towing and positioning;

[0038] Define the voyage mission, including the starting and ending points of the towing mission, the appearance of the cage and the special requirements of the owner; then decompose it into several stages according to its characteristics, towing and positioning mission requirements, and reasonably allocate engineering ships, tugboats, resources and towing technical solutions for each stage; and optimize the solution in combination with local meteorological and hydrological characteristics to ensure the best safety, economy and seaworthiness; accurately understand the various parameters of the cage: draft, center of gravity height, longitudinal and transverse inclination, and the variable load to meet the towing requirements of the towed object; determine the types and quantity of tugboats, engineering ships, and towing equipment;

[0039] S2, Preparation for lifting the cage;

[0040] According to the structural characteristics of the net cage, choose the appropriate towing connection method. From the net cage to the three-purpose tugboat I2, it is mooring nylon cable, dragon beard cable, 5m short cable, triangle plate, and main towing cable. Choose the appropriate towing point: the three-purpose tugboat I2 leads out two 25m mooring nylon cables from the towing eye plate at the corresponding positions of C5 and C9. The nylon cable is connected to the dragon beard cable. The φ70mm×70m dragon beard cable is connected to the main towing cable through a triangle plate (for easy connection, a short steel cable φ70mm×5m is added between the dragon beard cable and the triangle plate) using a 125t shackle. At the same time, arrange the harbor tugboat 4 as an escort ship.

[0041] At the wharf, the shore crane is used to assist the towing connection of the dragon beard cable. The anchor chains of the two buoy columns are connected to the trapezoidal opening position behind the eye plate, and the shackle is used to connect the nylon cable, and then it is connected to the dragon beard cable with a 125t shackle. Then the two dragon beard cables are connected by the triangle plate and the main towing cable for towing. Figure 1 shown.

[0042] The net cages need to be prepared with mooring nylon cables, dragon beard cables, and tow cables (turnaround). The overall height of the net cages is relatively high, and the three-purpose tugboat I2 should be equipped with sufficient special equipment for towing cables, such as towing cables, towing guns, etc., as well as triangles, shackles, main towing cables, etc. required for conventional towing.

[0043] According to the construction plan, an engineering vessel 1 and a three-purpose tugboat II3 completed the pre-laying work of four anchor chains in the designated sea area, so that the cages can be put in place and installed as soon as possible after arriving at the designated sea area.

[0044] S3, towing in the port;

[0045] A three-purpose tugboat I2 and a harbor tugboat 4 are used. The three-purpose tugboat I2 is located in front of the cage, and the harbor tugboat 4 is located on the starboard side of the cage. The three-purpose tugboat I2 tows the cage by connecting the mooring nylon cable, dragon whisker cable, short cable, triangle plate, short cable and main towing cable, and the harbor tugboat 4 hangs the stern of the cage by the nylon cable to control the navigation and buoyancy of the cage; according to the wind, current, sea conditions and other conditions at the time, under the command of the pilot, the main tugboat and the harbor tugboat cooperate with each other, leave the dock and enter the port exit channel.

[0046] S4, towing outside the port;

[0047] 1) Use the three-purpose tugboat I2 as the main tugboat, and the harbor tugboat 4 as the auxiliary tugboat to assist the rear of the net cage. During the towing, monitor the three-purpose tugboat I2, the harbor tugboat 4, the towing equipment, and the towed net cage. According to the course and distance, determine the safe navigation speed and enter the safe waters; after entering the safe waters, adjust the length of the towing cable according to the weather and sea conditions, hydrology, traffic density in the navigation area, water depth and draft, and the size of the towing force used. Because the towing of the net cage is different from that of an engineering ship or an offshore platform, which can be temporarily anchored by itself or plugged in to avoid the wind, the net cage has no anchoring equipment or plugging equipment, so temporary anchoring measures need to be formulated according to the characteristics of the net cage.

[0048] 2) Temporary anchoring: Connect a φ70mm×35m steel cable to the temporary anchor chain fastening point near the cage at point C5, and fasten the other end to the base of the eye plate at point C3 with a φ20mm steel wire to control the movement of the anchor chain. Figure 3As shown, a 200m anchor chain is laid on the three-purpose tugboat I2, and a spare anchor is connected. A φ38mm×60m short rope is connected to the spare anchor crown. A buoy with a buoyancy of 2t is equipped, a φ38mm×60m short rope is connected to the bottom, and a 10m nylon cable is connected to the top.

[0049] 3) Deployment and recovery of temporary anchoring: When the net cage arrives at the temporary anchoring point, the three-purpose tugboat I2 approaches the net cage and sends the personnel to the pontoon, unties the steel cable controlling the anchor chain and connects the winch steel cable of the three-purpose tugboat I2. After the personnel are withdrawn, the winch is used to receive the anchor chain to the stern deck of the three-purpose tugboat I2 and controlled by shark clamps, the deck anchor chain and the spare anchor are connected, and the buoy is connected to the crown of the spare anchor. When emergency release is required, the anchor can be directly pulled down into the water; when it is necessary to raise the anchor, the port tugboat 4 cooperates to control the net cage, and the three-purpose tugboat 2 first salvages the buoy, and then unties it after the buoy is on the deck. The working towline is used to connect the anchor head short rope to raise the anchor, and the anchor is pulled onto the deck. The shark clamp is used to clamp the anchor chain and untie the emergency anchor. The ship uses a chain buckle to lock the anchor chain, and then connects the anchor throwing and lifting working steel cable to tighten the anchor chain. After approaching the net cage, the personnel board the pontoon to untie the anchor chain and complete the recovery of the spare anchor.

[0050] S5, cage entry;

[0051] Before the cages enter the site, the engineering vessel 1, in cooperation with the three-purpose tugboat II3, completes the anchoring of its own six anchors and the pre-laying of four anchor chains for the cages, and waits near the upwind direction of the cages to be towed into the site;

[0052] like Figure 4 and Figure 5 As shown, after the cage enters the site, it gradually approaches the engineering ship 1. When the three-purpose tugboat I2 tows the cage and approaches the horizontal direction of the engineering ship 1, the port tugboat 4 tows the cage close to the tail of the engineering ship 1 to prepare to bring the cable, that is, the cage is towed at this time; the three-purpose tugboat II3 and a working boat 5 are on standby near the cage, ready to assist and respond to emergencies at any time;

[0053] After the net cage is towed over, it is towed by the harbor tugboat 4 to a distance from the stern of the engineering ship 1 that is within the range that can be carried. At this time, the mooring cable of the net cage is transported to the engineering ship 1 by the workboat 5. The engineering ship 1 cooperates with the harbor tugboat 4 and the three-purpose tugboat I2 to gradually tighten the four mooring cables to a suitable distance. After the net cage is moored to the engineering ship 1, the three-purpose tugboat II3 picks up the four anchor chains laid in advance respectively, and cooperates with the engineering ship 1 to connect the mooring cable of the net cage with the pre-laid anchor chain and buoy. During this process, the three-purpose tugboat I2 maintains a certain tension to tighten the net cage, and cooperates with the mooring cable of the engineering ship 1 to control the position of the net cage to prevent the net cage from being displaced, which would cause danger to the operation of the three-purpose tugboat II3 connecting the mooring chain of the net cage with the pre-laid anchor chain. Engineering vessel 1 uses the three-purpose tugboat I2 to adjust the length of six anchor cables and the positioning anchor to shift engineering vessel 1 and the cage to the vicinity of the end of the pre-laid anchor chain, and uses the three-purpose tugboat II3 to connect the mooring chain and the pre-laid anchor chain and perform tension tests, etc., to complete the connection of four pre-laid anchor chains and the mooring cable of the cage and perform tension tests. The installation work is completed when the requirements are met.

[0054] The cage undergoes a submersible test, after which it floats up and the acceptance personnel conduct acceptance of the cage connection and installation. After the acceptance is completed and qualified, the entire operation task is completed.

[0055] The method of the present invention solves the problem of towing and positioning control of large-scale aquaculture cages by decomposing the towing and positioning stages and using multiple ships to collaboratively control the cages for towing and positioning operations. The method is suitable for towing and multi-ship collaborative positioning control of large-scale aquaculture cages.

[0056] Matters not described in detail in the present invention are all known technologies.

[0057] The embodiments described above are merely descriptions of preferred implementation modes of the present invention, and are not intended to limit the scope of the present invention. Without departing from the design spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field should all fall within the protection scope determined by the claims of the present invention.

Claims

1. A method for towing a large-scale aquaculture cage at sea and coordinating the position of multiple vessels, characterized in that: The method comprises the following steps: S1. Develop a plan for cage towing and positioning; S2, Preparation for lifting the cage; The net cage needs to be prepared with mooring nylon cable, dragon beard cable and towing cable in advance. The overall height of the net cage is relatively high, and it is transported by a three-purpose tugboat equipped with sufficient special equipment for towing and the triangle plate, shackle and main towing cable required for conventional towing; According to the construction plan, an engineering vessel and a multi-purpose tugboat II will complete the pre-laying of four anchor chains in the designated sea area, so that the cages can be put in place and installed as soon as possible after arriving at the designated sea area; S3, towing in the port; The three-purpose tugboat I and the port tugboat are connected to the net cages through towing equipment respectively, and the three-purpose tugboat and the port tugboat cooperate with each other to tow the net cages away from the wharf and enter the port channel; S4, towing outside the port; The three-purpose tugboat I tows the cages and assists with the harbor tugboat hanging at the rear of the cages. During the towing, the tugboat, towing equipment and the floating state of the cages are monitored. According to the course and distance, the safe navigation speed is determined and the cages are entered into safe waters. S5, cage entry; Before the cages enter the site, the engineering vessel, in cooperation with the three-purpose tugboat II, completes the anchoring of its own six positioning anchors and the pre-laying of four anchor chains for the cages, and waits near the upwind direction of the cages to be towed into the site; After the cages enter the site, they gradually approach the engineering ship. When the three-purpose tugboat I tows the cages and approaches the engineering ship, the port tugboat tows the cages close to the stern of the engineering ship to prepare the cable, that is, the cages are towed at this time; the three-purpose tugboat II and a working boat are on standby near the cages, ready to assist and respond to emergencies at any time; After the cage is towed over, it is towed by the harbor tugboat to a distance from the stern of the engineering ship that is within the range of the cable. At this time, the mooring cable of the cage is transported to the engineering ship by the workboat. The engineering ship cooperates with the harbor tugboat and the three-purpose tugboat I to gradually tighten the four mooring cables to a suitable distance. After the cage is moored to the engineering ship, the three-purpose tugboat II picks up the four anchor chains laid in advance respectively, and cooperates with the engineering ship to connect the mooring cable of the cage with the pre-laid anchor chain and buoy. During this process, the three-purpose tugboat I maintains a certain tension to tighten the cage, and cooperates with the mooring cable of the engineering ship to control the position of the cage to prevent the cage from displacement. The engineering ship adjusts the length of the six anchor cables and the positioning anchor through the three-purpose tugboat I to shift the engineering ship and the cage to the vicinity of the end of the pre-laid anchor chain, and cooperates with the three-purpose tugboat II to complete the connection between the four pre-laid anchor chains and the mooring cable of the cage and conduct a tension test. The installation work is completed when the requirements are met.

2. A method for towing a large-scale aquaculture cage at sea and coordinating the positions of multiple vessels according to claim 1, characterized in that: In step S1, the scheme includes accurately obtaining various parameters of the cage, and determining the types and quantities of vessels in the towing and positioning stages.

3. A method for towing a large-scale aquaculture cage at sea and coordinating the positions of multiple vessels according to claim 1, characterized in that: In step S2, the dedicated cable-lifting equipment includes a cable-lifting rope and a cable-lifting gun.

4. A method for towing a large-scale aquaculture cage at sea and coordinating the positions of multiple vessels according to claim 1, characterized in that: In step S3, the three-purpose tugboat I tows the net cage by connecting the mooring nylon cable, the dragon beard cable, the short cable, the triangle plate, the short cable and the main tow cable, and the port tugboat hangs the stern of the net cage by the nylon cable to cooperate in controlling the navigation and floating state of the net cage.

5. A method for towing a large-scale aquaculture cage at sea and coordinating the positions of multiple vessels according to claim 1, characterized in that: In step S4, a steel cable is connected to the temporary anchor chain fastening point of the net box, and the other end is fastened to the root of the eye plate by a steel wire to control the movement of the anchor chain. The rest of the anchor chain is laid on the three-purpose tugboat I and the spare anchor, short rope, buoy and nylon cable are connected.

6. A method for towing a large-scale aquaculture cage at sea and coordinating the positions of multiple vessels according to claim 1, characterized in that: In step S4, after entering the safe waters, the length of the towline is adjusted in real time according to the weather and sea conditions, hydrology, traffic density in the navigation area, water depth and draft, and the amount of towing force used.

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