Anchor chain laying method

Abstract

The invention belongs to the technical field of anchor chain laying, and particularly relates to an anchor chain laying method applied to an offshore floating structure anchor chain. The anchor chain laying method is applied to an offshore floating structure anchor chain and comprises the steps that the whole anchor chain is arranged into at least one row in a preset operation area of an operation barge deck, each row of anchor chains are straightened and adjusted to be twisted, and a plurality of fixing devices are arranged at the two ends, in the bow and stern connecting line direction, of the preset area; adding color marks on the same side of the anchor chain; and a winch is used for carrying tension to enable the anchor chains to be sequentially lowered and laid on a seabed through a roller switch blade chain stopper, the winch is arranged at the position of a deck bow of the operation barge, and the roller switch blade chain stopper is arranged at the position of a stern. The anchor chain can be controlled to twist in the whole anchor chain laying process, and the construction quality and efficiency are greatly improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of anchor chain laying, and in particular relates to a laying method of anchor chains applied to offshore floating structures. Background Art

[0002] The buoy of the CALM single-point mooring system is moored and fixed by an anchor chain connected to an anchor or pile. There are requirements for the torsion of the anchor chain during installation. For example, the torsion of the anchor chain within a length of 100 meters should be less than 360 degrees. The anchor chain has a large chain diameter and is heavy. The work of arranging the anchor chain before installation is cumbersome. In addition, there are installation requirements for laying accuracy and torsion. If the anchor chain is directly dropped from the deck into the sea without taking control measures, the torsion of the anchor chain cannot be controlled and the safety risk of the ship and personnel is relatively large.

[0003] The commonly used construction schemes are as follows: Figure 1 As shown: the crane hook is used to lower the anchor chain in reverse, and the main and auxiliary hooks of the crane are used to cooperate to lower the anchor chain to the seabed. The overall process efficiency is low, and the anchor chain is prone to twisting. Summary of the invention

[0004] The disclosed embodiment proposes a method for laying anchor chains to ensure the laying accuracy and torsion of anchor chains for offshore floating structures during installation. The existing installation method of anchor chains is not easy to control the torsion of anchor chains, and the construction process is cumbersome and difficult, with low efficiency.

[0005] A first aspect of an embodiment of the present disclosure provides an anchor chain laying method, which is applied to anchor chains of offshore floating structures, comprising:

[0006] Arrange the entire anchor chain into at least one row in a preset working area on the deck of the working barge, and straighten and adjust the torsion of each row of the anchor chain, wherein a plurality of fixing devices are provided at both ends of the preset area along the line connecting the bow and the stern;

[0007] Adding color marking to the same side of the said anchor chain;

[0008] A winch is used to carry tension so that the anchor chain is lowered and laid on the seabed through a roller gate knife chain stopper in sequence, wherein the winch is arranged at the bow position of the deck of the working barge, and the roller gate knife chain stopper is arranged at the stern position.

[0009] In some embodiments of the present disclosure, arranging the entire anchor chain into at least one row in a preset area of ​​the deck of the working barge, and straightening each row of the anchor chain and adjusting the torsion thereof comprises:

[0010] Leading out the end of the anchor chain stacked at a preset position on one side of the deck of the working barge, and fixing the end to a first fixing device at one end of the preset working area;

[0011] Spreading out a portion of the anchor chain according to the length of the preset working area and fixing the spread anchor chain to a second fixing device at the other end of the preset working area, straightening the anchor chain between the first fixing device and the second fixing device and adjusting the torsion;

[0012] Continue to spread out the remaining anchor chains, arrange the anchor chains into multiple rows between the first fixing device and the second fixing device, and straighten each row of the anchor chains and adjust the torsion.

[0013] In some embodiments of the present disclosure, straightening the anchor chain and adjusting the torsion includes:

[0014] The winch guides the anchor chain through an open pulley, wherein the open pulley is arranged at the bow position of the deck of the working barge, and one end of the winch wire rope is connected to one end of the anchor chain through the open pulley;

[0015] The anchor chain is straightened by the cooperation of a winch and an opening block and the anchor chain is adjusted and twisted until one side of the anchor chain is facing upwards at every other anchor chain link.

[0016] In some embodiments of the present disclosure, adding color marking to the same side of the anchor chain includes:

[0017] Every other link is painted on the same side of the anchor chain link.

[0018] In some embodiments of the present disclosure, the method of using a winch to carry tension to sequentially lower the anchor chain through a roller blade chain stopper and lay it on the seabed includes:

[0019] Obtain the calculated value of winch carrying tension according to the actual anchor chain size, weight and water depth;

[0020] During construction, when the working barge moves with the main working ship, the winch carries the tension based on the calculated value and sequentially lowers the anchor chain through the roller blade chain stopper and lays it on the seabed.

[0021] In some embodiments of the present disclosure, the method of using a winch to carry tension to sequentially lower the anchor chain through a roller blade chain stopper and lay it on the seabed further includes:

[0022] In an emergency, the knife of the roller knife chain stopper is closed to stop the lowering of the anchor chain.

[0023] In some embodiments of the present disclosure, the stern of the working barge is further provided with a stern circular tube and a plurality of groups of limiting columns;

[0024] The stern circular tube is fixed to the rearmost end of the deck and has an arc-shaped surface, and the anchor chain is launched into the water through the surface;

[0025] The limiting column comprises a limiting groove for preventing the anchor chain from being displaced left and right, and is used to ensure that the anchor chain enters the roller blade chain stopper or the stern round tube in a specified direction.

[0026] In some embodiments of the present disclosure, the step of lowering the anchor chain to the seabed through a roller blade chain stopper comprises:

[0027] The anchor chain passes through the first limiting column and enters the roller gate knife chain stopper, and then passes through the second limiting column and enters the stern circular tube after coming out of the roller gate knife chain stopper, and enters the water from the stern circular tube.

[0028] In some embodiments of the present disclosure, the fixing device is a shackle or a D-ring.

[0029] In some embodiments of the present disclosure, the preset working area can accommodate at least two anchor chains to be arranged simultaneously, or one anchor chain is being laid while another anchor chain is being laid.

[0030] In summary, the anchor chain laying method provided by each embodiment of the present disclosure straightens and adjusts the torsion of the anchor chain when arranging the anchor chain on the deck of the working barge, paints the anchor chain to indicate whether torsion occurs, and carries the tension through the roller gate knife chain stopper for laying. The back-twisting and straightening function of the roller gate knife chain stopper ensures that the anchor chain is finally laid on the seabed in one direction, thereby achieving the effect of controlling the torsion of the anchor chain throughout the process. At the same time, dual chains can be arranged simultaneously in the deck arrangement area, and another anchor chain can be arranged while one anchor chain is laid, so that multiple anchor chains can be laid quickly, efficiently and continuously, thereby greatly improving the construction quality and efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] The features and advantages of the present disclosure will be more clearly understood by referring to the accompanying drawings, which are schematic and should not be construed as limiting the present disclosure in any way. In the accompanying drawings:

[0032] Figure 1 It is a schematic diagram of the existing method for laying anchor chains for offshore floating structures;

[0033] Figure 2 is a schematic diagram of a work barge deck shown in some embodiments of the present disclosure;

[0034] Figure 3 is a flow chart of an anchor chain laying method shown in some embodiments of the present disclosure;

[0035] Figure 4a-4f is a schematic diagram of arranging anchor chains on a working barge deck according to some embodiments of the present disclosure;

[0036] Figure 5 It is a schematic diagram of painting an anchor chain shown in some embodiments of the present disclosure. DETAILED DESCRIPTION

[0037] In the detailed description below, many specific details of the present disclosure are set forth by way of example in order to provide a thorough understanding of the relevant disclosure. However, it will be apparent to one of ordinary skill in the art that the present disclosure can be implemented without these details. It should be understood that the use of the terms "system," "device," "unit," and / or "module" in the present disclosure is a method for distinguishing different parts, elements, parts, or assemblies at different levels in a sequential arrangement. However, these terms may be replaced by other expressions if other expressions can achieve the same purpose.

[0038] It should be understood that when a device, unit or module is referred to as being "on," "connected to," or "coupled to" another device, unit or module, it may be directly on, connected to, coupled to, or communicating with other devices, units or modules, or there may be intermediate devices, units or modules, unless the context clearly indicates an exception. For example, the term "and / or" as used in this disclosure includes any and all combinations of one or more of the relevant listed items.

[0039] The terms used in this disclosure are only for describing specific embodiments and are not intended to limit the scope of this disclosure. As shown in the specification and claims of this disclosure, unless the context clearly indicates an exception, the words "one", "a kind" and / or "the" do not specifically refer to the singular, but may also include the plural. Generally speaking, the terms "include" and "comprise" only indicate the inclusion of clearly identified features, wholes, steps, operations, elements and / or components, and such expressions do not constitute an exclusive list, and other features, wholes, steps, operations, elements and / or components may also be included.

[0040] Figure 2 Schematic diagram of a deck of a working barge shown in some embodiments of the present disclosure. When the working barge moves with the main working ship, the working barge puts the anchor chain arranged on the deck into the sea from under the stern.

[0041] like Figure 2 As shown:

[0042] A plurality of anchor chain stacking areas are provided on both sides of the deck of the working barge, where the anchor chains are initially stacked.

[0043] A winch and an open block are arranged at the bow of the deck of the working barge, and a plurality of fixing devices such as a shackle and a D-ring are arranged beside the winch and the open block is fixed to the D-ring through the shackle.

[0044] The deck stern of the work barge is provided with a roller gate knife chain stopper, a stern circular tube and a plurality of groups of limit columns. The roller gate knife chain stopper is used to prevent the anchor chain passing through it from twisting, thereby ensuring that the anchor chain is eventually laid on the seabed in one direction; and in an emergency, the anchor chain can be locked by closing the gate knife so that it cannot be lowered. The stern circular tube is formed by cutting off a quarter of a circular tube in the axial direction, and the remaining three quarters are inverted at the very end of the stern, wherein the cross section of the stern circular tube fits the deck, and the arc-shaped surface faces the sea surface. The limit column includes a limit groove to prevent the anchor chain from shifting left and right, and is used to ensure that the anchor chain enters the roller gate knife chain stopper or the stern circular tube in a specified direction. A fixing device is also provided at the corresponding position of the stern.

[0045] The work area is formed between the fixtures at the bow and stern of the ship. The anchor chain to be laid needs to be pre-arranged in the work area to straighten the anchor chain and adjust the twist, and paint the anchor chain at the same time. The anchor chain being laid also extends from the stern to the work area. The area of ​​the work area and the ancillary facilities, such as winches, stacking areas, and fixtures, need to be able to accommodate at least two anchor chains to be laid at the same time, or one anchor chain can be laid while another anchor chain is being laid.

[0046] Figure 3 FIG. 1 is a flow chart of a method for laying an anchor chain as shown in some embodiments of the present disclosure. Figure 3 As shown, the method includes:

[0047] S310, arranging the entire anchor chain into at least one row in a preset working area on the deck of the working barge, and straightening and adjusting the torsion of each row of the anchor chain, wherein a plurality of fixing devices are provided at both ends of the preset area along the direction of the bow and stern line.

[0048] Specifically, Figure 4a-4f It is a schematic diagram of arranging anchor chains on the deck of a working barge according to some embodiments of the present disclosure.

[0049] Initially, the anchor chain is hoisted to the deck of the working barge by a crane and stacked in the preset stacking areas on both sides of the deck of the working barge.

[0050] When the layout starts, Figure 4a As shown, the end of the anchor chain stacked in the stacking area is led out, the end is pulled to a first fixing device near one end of the bow in a preset working area and fixed at the position.

[0051] Then, if Figure 4b As shown, the anchor chain is partially spread out according to the length of the preset working area, and the spread anchor chain is pulled to the preset working area near the stern end and fixed to the second fixing device at the position.

[0052] Then, if Figure 4c As shown, one end of the winch wire rope at the bow is connected to the end of the anchor chain through an open pulley, and the open pulley is arranged at the bow position of the working barge deck to guide the anchor chain. The anchor chain between the first fixing device and the second fixing device is straightened by the cooperation of the winch and the open pulley, and the anchor chain is adjusted and twisted until one side of the anchor chain is facing upwards in every other anchor chain link.

[0053] Continue to spread out the remaining anchor chains and arrange the anchor chains into multiple rows between the first fixing device and the second fixing device. Figure 4d , and straighten and adjust the twist of the newly spread anchor chain arranged between the first fixing device and the second fixing device, such as Figure 4e Finally, the entire anchor chain is arranged in the preset working area. Figure 4f .

[0054] S320, adding color markings to the same side of the anchor chains.

[0055] Specifically, Figure 5 Schematic diagram of painting anchor chain shown in some embodiments of the present disclosure. Figure 5 As shown, every other link is painted with colored paint on the same side of the anchor chain link. The purpose of painting with colored paint is to form a striking visual mark, so that when the anchor chain is twisted, it can be observed intuitively and quickly. So that corresponding corrective measures can be taken. Painting the anchor chain is a visual quality control method for the laying of the anchor chain.

[0056] S330, using a winch to carry tension to sequentially lower the anchor chain through a roller gate knife chain stopper and lay it on the seabed, wherein the winch is arranged at the bow position of the deck of the working barge, and the roller gate knife chain stopper is arranged at the stern position.

[0057] Specifically, the tension of the roller gate knife chain stopper on the ship is first calculated according to the actual anchor chain size and weight, and then the calculated value of the winch carrying tension is calculated according to the tension of the roller gate knife chain stopper and the water depth, as shown in Table 1. During the construction period, when the working barge moves with the main working ship, the winch sequentially lowers the anchor chain through the roller gate knife chain stopper and lays it on the seabed based on the calculated value carrying tension.

[0058] In some embodiments of the present disclosure, the organized anchor chain is introduced from the working area into the first limit column, enters the roller gate knife chain device through the first limit column, and then enters the stern circular tube through the second limit column after coming out of the roller gate knife chain device, and enters the water from the stern circular tube.

[0059] The limit column is used to ensure that the anchor chain enters the roller gate knife chain stopper or the stern round tube in the specified direction. The roller gate knife chain stopper is used to prevent the anchor chain passing through it from twisting, so as to ensure that the anchor chain is finally laid on the seabed in one direction; and in an emergency, the anchor chain can be locked by closing the gate knife so that it cannot be lowered. The arc-shaped surface of the stern round tube can prevent the bending radius of the anchor chain passing through it from being too small, so that it is stuck at the stern and cannot enter the water.

[0060]

[0061] Table 1

[0062] In some embodiments of the present disclosure, the preset working area includes a sufficiently large area and a sufficient number of auxiliary equipment, such as a winch, a stacking area, and a fixing device, so that double chains can be arranged simultaneously or another anchor chain can be prepared for arrangement while laying an anchor chain, thereby improving efficiency and realizing rapid, efficient and continuous laying of multiple anchor chains.

[0063] In summary, the anchor chain laying method provided by each embodiment of the present disclosure straightens and adjusts the torsion of the anchor chain when arranging the anchor chain on the deck of the working barge, paints the anchor chain to indicate whether torsion occurs, and carries the tension through the roller gate knife chain stopper for laying. The back-twisting and straightening function of the roller gate knife chain stopper ensures that the anchor chain is finally laid on the seabed in one direction, thereby achieving the effect of controlling the torsion of the anchor chain throughout the process. At the same time, dual chains can be arranged simultaneously in the deck arrangement area, and another anchor chain can be arranged while one anchor chain is laid, so that multiple anchor chains can be laid quickly, efficiently and continuously, thereby greatly improving the construction quality and efficiency.

[0064] It should be understood that the above specific embodiments of the present disclosure are only used to illustrate or explain the principles of the present disclosure, and do not constitute a limitation of the present disclosure. Therefore, any modifications, equivalent substitutions, improvements, etc. made without departing from the spirit and scope of the present disclosure should be included in the protection scope of the present disclosure. In addition, the claims attached to the present disclosure are intended to cover all changes and modifications that fall within the scope and boundaries of the attached claims, or the equivalent forms of such scope and boundaries.

Claims

1. A method for laying anchor chains, applied to anchor chains of offshore floating structures, characterized in that: include: Arrange the entire anchor chain into at least one row in a preset working area on the deck of the working barge, and straighten and adjust the torsion of each row of the anchor chain, wherein a plurality of fixing devices are provided at both ends of the preset area along the line connecting the bow and the stern; Adding color marking to the same side of the said anchor chain; A winch is used to carry tension so that the anchor chain is lowered and laid on the seabed through a roller gate knife chain stopper in sequence, wherein the winch is arranged at the bow position of the deck of the working barge, and the roller gate knife chain stopper is arranged at the stern position.

2. The method according to claim 1, characterized in that The method of arranging the entire anchor chain into at least one row in a preset area of ​​the deck of the working barge, and straightening and adjusting the torsion of each row of the anchor chain comprises: Leading out the end of the anchor chain stacked at a preset position on one side of the deck of the working barge, and fixing the end to a first fixing device at one end of the preset working area; Spreading out a portion of the anchor chain according to the length of the preset working area and fixing the spread anchor chain to a second fixing device at the other end of the preset working area, straightening the anchor chain between the first fixing device and the second fixing device and adjusting the torsion; Continue to spread out the remaining anchor chains, arrange the anchor chains into multiple rows between the first fixing device and the second fixing device, and straighten each row of the anchor chains and adjust the torsion.

3. The method according to claim 1 or 2, characterized in that: Straightening the anchor chain and adjusting the torsion include: The winch guides the anchor chain through an open pulley, wherein the open pulley is arranged at the bow position of the deck of the working barge, and one end of the winch wire rope is connected to one end of the anchor chain through the open pulley; The anchor chain is straightened by the cooperation of a winch and an opening block and the anchor chain is adjusted and twisted until one side of the anchor chain is facing upwards at every other anchor chain link.

4. The method according to claim 1, characterized in that The adding of color marking on the same side of the anchor chain comprises: Every other link is painted on the same side of the anchor chain link.

5. The method according to claim 1, characterized in that The method of using a winch to carry tension to sequentially lower the anchor chain through a roller blade chain stopper and lay it on the seabed comprises: Obtain the calculated value of winch carrying tension according to the actual anchor chain size, weight and water depth; During construction, when the working barge moves with the main working vessel, the winch carries the tension based on the calculated value and sequentially lowers the anchor chain through the roller blade chain stopper and lays it on the seabed.

6. The method according to claim 1, characterized in that The method of using a winch to carry tension to sequentially lower the anchor chain through a roller blade chain stopper and lay it on the seabed also includes: In an emergency, the knife of the roller knife chain stopper is closed to stop the lowering of the anchor chain.

7. The method according to claim 5, characterized in that: The stern of the working barge is also provided with a stern circular tube and multiple groups of limiting columns; The stern circular tube is fixed to the rearmost end of the deck and has an arc-shaped surface, and the anchor chain is launched into the water through the surface; The limiting column comprises a limiting groove for preventing the anchor chain from being displaced left and right, and is used to ensure that the anchor chain enters the roller gate knife chain stopper or the stern round tube in a specified direction.

8. The method according to claim 7, characterized in that The method of lowering the anchor chain to the seabed through the roller blade chain stopper comprises: The anchor chain passes through the first limiting column and enters the roller gate knife chain stopper, and then passes through the second limiting column and enters the stern circular tube after coming out of the roller gate knife chain stopper, and enters the water from the stern circular tube.

9. The method according to claim 1, characterized in that: The fixing device is a shackle or a D-ring.

10. The method according to claim 1, characterized in that Also includes: The preset working area can accommodate at least two anchor chains to be arranged simultaneously, or one anchor chain can be arranged while another anchor chain is being laid.

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