JP2020039254A - Installation construction method for floating fish reef - Google Patents

Abstract

To provide an installation construction method for a floating fish reef capable of shortening a construction time because a mooring line is enabled to be drawn out from a position on a barge to the sea and be spread in a short period of time, capable of immersing an anchor with high positional accuracy, and capable of appropriately spreading the mooring rope while inhibiting the mooring line from being twisted.SOLUTION: A barge 1 equipped with a floating fish reef body 5, an anchor 6 to be immersed on a sea bottom, and a mooring line 7 that is constituted by a lower chain 8 connected to the anchor, an upper chin 9 connected to the floating fish reef body, and a mooring rope 10 connecting the chains to connect the floating fish reef body with the anchor is disposed in an installation sea area for the floating fish reef body. The lower chain 8's lower end 8a side and upper end 8b side and the upper chin 9 are temporarily fixed at X, Y, Z on the barge in advance. First, an intermediate part Q of the mooring rope is drawn by a work boat 2 to draw out the mooring rope from the barge to the sea S.SELECTED DRAWING: Figure 4

Description

  The present invention enables the mooring line to be pulled out from the barge to the sea in a short time and deployed, thereby shortening the construction time, and also enabling the anchor to be laid down with high positional accuracy, and the mooring can be moored. The present invention also relates to a method for installing and constructing a floating fish reef that can be appropriately deployed without causing twisting or the like of a rope.

  Floating reefs are installed by mooring the main body of the floating reef to anchors submerged on the seabed with mooring lines, and the floating reef body located on the sea surface or the surface layer of the sea gathers fish and other marine life. I have.

  Background art related to this type of floating reef is disclosed in Patent Documents 1 and 2. In the “mooring rope of a floating body” of Patent Document 1, a buoy is moored by a chain, a swivel, an FRP rod, a swivel, and a chain on an anchor submerged on the sea floor. The FRP rod has a higher tensile strength than conventional ropes made of synthetic fibers and withstands a large amount of tension. Therefore, it can be made thin. By reducing the thickness, the tidal resistance is reduced, and the tension applied to the FRP rod is also reduced by a synergistic effect, so that the preliminary buoyancy of the buoy, the diameter of the chain, and the holding force of the anchor can be reduced.

  Patent Document 2 “Floating fish reef” has a floating body, an anchor, and a mooring line connecting the floating body and the anchor. When the speed of the tidal current is slow, the upper part of the floating body comes out on the sea surface, and when the speed of the tidal current is fast, The buoyancy of the floating body is adjusted so that the entire floating body is drawn into the sea, and a sign buoy is attached to the floating body via a mooring line.

JP-A-6-158571 JP 2007-236291 A

  FIG. 6 shows an example of the state of installation and construction of a conventional floating fish reef. The floating reef body a, the mooring line b, and the anchor c are mounted on a barge d and transported to the installation sea area.

  The mooring line b is usually about 1.5 times as long as the water depth of the installation sea area. For example, if the water depth is 1,000 to 1,300 m, the length is about 1,500 to 2,000 m. .

  The mooring line b generally includes a steel lower chain e having a lower end connected to the anchor c, a steel upper chain f having an upper end connected to the floating reef main body a, and the upper chain f and the lower chain f. And a synthetic fiber mooring rope g connecting the chain e. If the water depth is about 1,000 m, the upper chain f is about 50 m, the lower chain e is about 200 to 300 m, and the remaining length is about The mooring rope g is used.

  On the barge d, the mooring cable b having such a long length is divided into an upper chain f, a mooring rope g, and a lower chain e, and placed in an orderly manner.

  In the installation work of the floating fish reef in the installation sea area, first, the floating fish reef main body a is lowered from the boat d to the sea s by the crane of the work boat h accompanying the boat d.

  Next, the floating reef main body a is connected to the work boat h by the towing rope i, and the floating fish reef main body a is towed by the work boat h. The mooring line b is deployed from the barge d toward the sea s by towing the floating reef body a with the work boat h. Specifically, the upper chain f is first drawn out from the barge d to the sea s, and subsequently, the mooring rope b is drawn out from the barge d to the sea s, and the mooring line b is deployed. At this time, the lower chain e is left on the barge d.

  Next, when only the lower chain e and the anchor c remain on the barge d, the anchor c is dropped from the barge d to the sea s. When the anchor c is dropped, the lower chain e is pulled out from the barge d to the sea s. When the anchor c has landed and the entire mooring line b is pulled out to the sea s, the main body a of the floating reef is moored by the submerged anchor c in the installation sea area. The following problems were encountered in the installation and construction of conventional floating reefs.

  (1) Since the work of pulling out the mooring line b from the barge d to the sea s and deploying it is performed by the work boat h towing the floating reef body a, starting from the upper chain f and pulling out almost all of the mooring rope g. In addition, the floating fish reef main body a must be towed for the entire length thereof, which requires a large amount of work time.

  (2) To drop the anchor c into the sea s in a state where the floating reef main body a is lowered to the sea s and the deployment distance and the deployment range of the portion extending from the upper chain f to the mooring rope g are wide. The sinking of the anchor c causes the floating fish reef main body a to be sent to the sea s in advance and pulled by the mooring rope g or the like to become a resistance, and the anchor c to be landed at an intended position. Therefore, it was not possible to secure a high accuracy of the sunk position of the anchor c.

  (3) If the placement accuracy of the anchor c is poor, the installation position and the installation depth of the anchor c will be different from the plan due to the influence of the seabed gradient or the like, and as a result, the installation position of the floating reef main body a will shift. Or the installation depth is different, making it difficult to obtain the expected crowding effect, and receiving external forces such as water pressure and waves that exceed the design strength, raising concerns about durability and safety. In addition, when a situation such as crossing a water area boundary occurs, there is a possibility that a problem of fishery coordination with a local government or a fishery union may occur.

  (4) The mooring rope g constituting the mooring line b is composed of an upper rope j having a specific gravity which tends to sink and a lower rope k which tends to float, and the upper rope j is shackled to an upper chain f. The upper chain f sinks in the direction of the seabed from the floating reef body a toward the connecting hardware m, and the upper rope j floats from the connecting hardware m toward the sea surface. The mooring line b may be twisted near the heavy metal fitting m due to the movement or tide of the floating fish reef main body a that has been lowered to the sea s, and this may cause kink or entanglement. Was concerned.

  The present invention has been made in view of the above-mentioned conventional problems, and it is possible to pull out a mooring line from a barge to the sea in a short time and deploy the mooring line, shorten the construction time, and It is an object of the present invention to provide a method for installing and constructing a floating reef, which can be sunk with high positional accuracy, and in which a mooring line can be appropriately deployed without twisting or the like.

  The method for installing and constructing a floating reef according to the present invention includes a floating reef main body for gathering marine life such as fish, an anchor for sinking on the seabed, a lower chain having a lower end connected to the anchor, and a floating reef main body. An upper chain to which the upper end is connected, and a mooring rope that is lighter than the upper and lower chains and that connects these chains, are provided with a mooring line for connecting the floating reef body to the anchor. A barge and at least one workboat are arranged in the sea area where the floating reef body is installed, and at least the lower and upper ends of the lower chain and the upper chain are temporarily fixed to the barge in advance. First, by pulling at least the mooring rope from the barge to the sea by towing the intermediate portion of the mooring rope with the work boat, The temporary anchor at the lower end of the lower chain is released by lowering the anchor so that the anchor is settled on the seabed and the mooring rope is moored by the anchor via the lower chain. From the barge to the sea, and then release the temporary fix at the upper end side of the lower chain, pull out the entire lower chain from the barge to the sea, and then remove the floating reef body from the barge. Moving to the sea, releasing the temporary fixation of the upper chain, pulling out the upper chain from the barge to the sea, and mooring the floating reef main body from the seabed with the mooring line.

  At least when the mooring rope is withdrawn from the barge to the sea, an intermediate portion of the mooring rope and the work boat are connected by a towing rope.

  The mooring rope is characterized in that an upper rope having a high specific gravity capable of sinking in the sea and a lower rope having a low specific gravity capable of floating in the sea are connected in series.

  The lower rope is longer than the upper rope, and the workboat that pulls an intermediate portion of the mooring rope pulls the lower rope.

  In the method for installing and constructing a floating reef according to the present invention, the mooring line can be pulled out from the barge to the sea in a short time and deployed, so that the construction time can be shortened. And the mooring line can be deployed properly without twisting or the like.

It is a perspective view explaining the 1st process of one suitable embodiment of the installation construction method of the floating fish reef concerning the present invention. FIG. 2 is a perspective view illustrating a second step following the first step in FIG. 1. FIG. 3 is a perspective view illustrating a third step following the second step in FIG. 2. FIG. 4 is a perspective view illustrating a fourth step following the third step in FIG. 3. FIG. 5 is a perspective view illustrating a fifth step following the fourth step in FIG. 4. It is a perspective view explaining an example of the installation construction situation of the conventional floating fish reef.

  Hereinafter, a preferred embodiment of a method for installing and constructing a floating reef according to the present invention will be described in detail with reference to the accompanying drawings. 1 to 5 show a method of installing and constructing a floating reef according to the present embodiment according to a work procedure.

  At the time of installation of the floating fish reef, a barge 1 that carries the equipment of the floating fish reef and transports it to the installation sea area, and at least one work boat 2, 3, 4 that supports the installation and construction in the installation sea area is used. In the illustrated example, in addition to the two work boats 2 and 4, a guard boat is shown as the work boat 3 for ensuring safety in the installation sea area (see FIG. 5).

  The equipment of the floating reef mounted on the barge 1 mainly includes a floating reef main body 5 that is moved to the sea S for gathering marine life such as fish, an anchor 6 for sinking on the seabed, and a floating reef. And a mooring line 7 for connecting the main body 5 to the anchor 6.

  After the floating reef main body 5, the anchor 6, and the mooring line 7 are individually mounted on the barge 1, the upper end 7a of the mooring line 7 is connected to the floating fish reef main body 5, and the lower end 7b of the mooring line 7 is The anchor 6 is connected to the anchor 6 and the main body 5 of the floating reef is connected to the mooring line 7. Examples of the floating reef main body 5 include a type that floats without sinking on the sea surface, a type that floats and sinks at the tidal flow velocity on the sea surface, which is usually called a surface floating reef.

  The mooring cable 7 is mainly composed of a lower chain 8 made of steel or the like on the anchor 6 side, an upper chain 9 made of steel or the like on the floating reef main body 5 side, and lighter (specific gravity is lower than those of the upper chain 9 and the lower chain 8). (Small) made of synthetic resin or the like, and is composed of a mooring rope 10 connecting the upper chain 9 and the lower chain 8.

  A lower end 8 a (7 b) which is one end of the lower chain 8 is connected to the anchor 6. An upper end 9 a (7 a) which is one end of the upper chain 9 is connected to the floating reef main body 5. Both ends of the mooring rope 10 are connected to the lower end 9b, which is the other end of the upper chain 9, and the upper end 8b, which is the other end of the lower chain 8, so that the chains 8, 9 are connected in series by the mooring rope 10. Is done.

  Further, the mooring rope 10 may be configured by connecting a series of an upper rope 10a having a heavy specific gravity capable of sinking in the sea S and a lower rope 10b having a lower specific gravity than the upper rope 10a capable of floating in the sea S. preferable.

  For example, if the water depth is about 1,300 m, the total length of the mooring cable 7 is about 2,000 m, the length of the upper chain 9 is about 50 m, the length of the lower chain 8 is about 250 m, The remaining length is about 1,700 m, and about 40% of the length of the mooring rope 10 is constituted by the upper rope 10a, and about 60% is constituted by the lower rope 10b. That is, the lower rope 10b has a longer length than the upper rope 10a.

  If the specific gravity of the lower rope 10b is lighter than that of seawater, the lower rope 10b tends to rise from the connecting point with the lower chain 8, and similarly, if the specific gravity of the upper rope 10a is heavier than seawater, The upper rope 10a tends to sink, and in any case, it is possible to prevent such inconvenience that the ropes 10a and 10b are entangled with the chains 8 and 9 due to the tidal force acting during and after installation of the floating reef. In addition, it is possible to suppress a decrease in the strength of the connecting portion between the ropes 10a, 10b and the chains 8, 9.

  The lower chain 8 and the upper chain 9 are both folded back and forth from the upper end (one end) 8b, 9a to the lower end (the other end) 8a, 9b, and are laid flatly and one after another without being overlapped. 1 mounted.

  The upper rope 10a is mounted on the barge 1 in such a manner that a plurality of bundles 10x in an array that is folded back and forth from the upper end (one end) to the lower end (the other end) are arranged.

  The lower rope 10b is mounted on the barge 1 in such a manner that a plurality of coils 10y wound in series are arranged from the upper end (one end) to the lower end (the other end). The floating reef body 5 and the anchor 6 are also placed on the barge 1.

  As will be described later, before the anchor 6 is dropped from the barge 1 to the sea S, the lower chain 8 is temporarily fixed (temporarily fixed) X, Y at least on the lower end 8 a side and the upper end 8 b side to the barge 1. Is done. When the temporary fixing X and Y are released, the lower chain 8 can be pulled out to the sea S. Incidentally, the temporary fixing Y is set in order to prevent the entire lower chain 8 from being thrown into the sea S at once at a time when the temporary fixing X is released, so that the anchor 6 does not land on the seabed. Therefore, the lower chain 8 is drawn not only from the upper end 8b side and the lower end 8a side, but also a series of lower chains 8 from the barge 1 to the sea S in order from the lower end 8a side to the upper end 8b side. It is preferable to temporarily fix a plurality of appropriate places to the barge 1.

  As will be described later, the upper chain 9 is temporarily fixed Z to the barge 1 at least at any point in the length direction before the main body 5 is moved from the barge 1 to the sea S. When the temporary fixing Z is released, the entire upper chain 9 can be pulled out to the sea S. Regarding the upper chain 9, it is preferable that the portion around the lower end 9 b side is temporarily fixed to the barge 1.

  When the barge 1 and the work boats 2 to 4 arranged as shown in FIG. 1 reach the sea area where the floating fish reef main body 5 is installed, the installation of the floating fish reef is performed in the order shown in FIGS.

  One of the workboats 2 comes alongside the barge 1 to connect the mooring ropes 10 of the mooring lines 7 on the barge 1 and the workboats 2 at sea. At this time, it is preferable to connect the work boat 2 and the mooring rope 10 using the tow rope 11 towed by the work boat 2. When the work boat 2 uses the tow rope 11, the tow rope 11 is connected to an intermediate portion Q of the mooring rope 8, specifically, to a substantially central portion in the longitudinal direction of the mooring rope 10.

  Then, by pulling the intermediate portion Q of the mooring rope 10 by maneuvering the work boat 2, the mooring rope 10 is pulled out from the barge 1 to the sea S and deployed as shown in FIG. At this time, it is preferable that the upper chain 9 be continuously pulled out from the barge 1 to the sea S to the position where the upper chain 9 is temporarily fixed Z as shown in FIG.

  By connecting the intermediate portion Q of the mooring rope 10 to the work boat 2 and towing it to the sea S, the mooring rope is compared with the conventional case where the floating reef body is towed and the mooring line is sequentially pulled out from the upper chain. The entire mooring rope 10 (including a part of the upper chain 9) and the like can be deployed to the sea S with a towing distance and a towing time that is approximately half the length of 10, so that the work time can be reduced by half and work can be performed quickly. Can be completed.

  Further, when the mooring line 7 is pulled out to the sea S and deployed, it takes a lot of work time to tow the floating reef body which causes a great resistance, and unlike the conventional case where the boat maneuvering operation is complicated, the floating operation is difficult. With the fish reef body 5 left on the barge 1, only the mooring ropes 10 are pulled out from the barge 1 and deployed to the sea S, so that the mooring ropes 10 can be deployed smoothly, quickly, and easily. Work can be completed.

  An intermediate portion Q of the mooring rope 10 connected to the work boat 2 and towed by the work boat 2 is a lower rope 10b having a lower specific gravity than seawater. As described above, since the work boat 2 is connected to the lower rope 10b which tends to float and the mooring rope 10 is towed, the entire mooring rope 10 can be smoothly deployed to the sea S by easy boat maneuvering. .

  Also, when the mooring rope 10 is towed, the upper rope 10a tends to sink and the lower rope 10b tends to float, so that the ropes 10a and 10b can be prevented from becoming entangled.

  Next, as shown in FIG. 4, the anchor 6 is dropped into the sea S. The tow rope 11 is removed as preparation for the drop operation or at the start of the drop operation. Removal of the tow rope 11 is performed by disconnecting the connection at a connection point between the tow rope 11 and the work boat 2 or the mooring rope 10. When the tow rope 11 is not used, the connection between the work boat 2 and the mooring rope 10 is released. At this time, the temporary fixing Z of the upper chain 9 is left as it is.

  When the anchor 6 is dropped into the sea S, the temporary fixing X on the lower end 8a side of the lower chain 8 is released, whereby the anchor 6 can be dropped from the barge 1 and the upper end 8b side of the lower chain 8 , The lower chain 8 is drawn out to the sea S in accordance with the sinking of the anchor 6. When the lower chain 8 is temporarily fixed at a plurality of locations, the temporary fixing is sequentially released as the lower chain 8 is sequentially pulled out.

  Accordingly, when the anchor 6 is dropped from the barge 1 to the sea S, the anchor 6 is pulled by the anchor 6, and almost the majority of the lower chain 8 reaches the sea S up to the position of the temporary fixing Y on the upper end 8 b side of the lower chain 8. It is drawn toward.

  Subsequently, the temporary fixing Y on the upper end 8b side of the lower chain 8 is released. Thereby, the entire lower chain 8 is pulled out from the barge 1 to the sea S. By pulling out the lower chain 8 with the drop of the anchor 6 to the sea S, the anchor 6 is settled on the sea floor, and the mooring rope 10 and the like which have been deployed in the sea S in advance are passed through the lower chain 8. And anchored at anchor 6.

  When the anchor 6 is dropped, the floating reef main body 5 is placed on the barge 1 and the mooring ropes 10 and the like are only deployed in the sea S, so they are sent in advance and pulled by the mooring ropes. The anchor 6 pulls the lower chain 8 and the mooring rope 10 connected to the lower chain 8 without receiving such resistance, unlike the conventional method in which the floating reef main body in a state where the body of the floating fish reef becomes a resistance of the sinking anchor. However, it can sink almost straight toward the seabed directly below the barge 1.

  Therefore, the anchor 6 can be properly settled at the intended position, and the anchoring position accuracy of the anchor 6 can be ensured high.

  Since the accuracy of the anchoring position of the anchor 6 can be improved, the installation position and the installation depth of the anchor 6 can be made as planned, whereby the expected gathering effect can be obtained, and the water pressure and the waves exceeding the design strength can be obtained. High durability and safety can be ensured without receiving external force such as the above, and the situation such as crossing the water area can be prevented. It is possible to eliminate the possibility of occurrence.

  Then, as shown in FIG. 5, the floating reef main body 5 mounted on the barge 1 is moved from the barge 1 to the sea S by a heavy machine such as a crane provided on the barge 1 or the work boat 4. Move. The rope 12 may be connected to the work boat 4 so that the worker can come and go with the floating fish reef main body 5 moved to the sea S in order to perform an operation of removing the floating fish reef main body 5 from a crane or the like. Note that the connection of the rope 12 is released when the work on the floating reef main body 5 is completed.

  Next, the temporary fixing Z of the upper chain 9 is released, and the entire upper chain 9 is pulled out from the barge 1 to the sea S. The floating reef main body 5 transferred to the sea S in this manner is moored from the sea floor via the mooring line 7 by the anchor 6 already laid on the sea floor.

  After the mooring cable 7 is moored by the anchor 6, the floating reef body 5 is moved to the sea S, so that the upper chain and the upper rope are connected by the movement of the floating fish reef body that has been previously lowered into the sea. In contrast to the conventional case in which kink or entanglement is likely to occur at a location, it is possible to prevent a problem such as entanglement in the mooring line 7 and to secure high soundness of the mooring line 7 in the installed state.

  In the method for installing and constructing a floating reef according to the present embodiment described above, the mooring line 7 can be pulled out from the barge 1 to the sea S in a short time and deployed, thereby shortening the construction time. At the same time, the anchor 6 can be sunk with high positional accuracy, and the mooring line 7 can also be appropriately deployed without twisting or the like.

Reference Signs List 1 barge 2-4 work boat 5 floating reef main body 6 anchor 7 mooring line 8 lower chain 8a lower chain lower end 8b lower chain upper end 9 upper chain 9a upper chain upper end 10 mooring rope 10a upper rope 10b lower rope 11 towing rope Q Intermediate part of mooring rope S Sea X ~ Z Temporary fixing

Claims (4)

Floating reef main body for gathering marine life such as fish, anchor for submerging on the sea floor, lower chain connected to the lower end of the anchor, upper chain connected to the upper end to the floating reef main body, and these upper chains A barge and at least one work boat, which are lighter than the lower chain and a mooring rope for connecting these chains, and which are equipped with a mooring line for connecting the floating reef body to the anchor. Placed in the sea where the floating reef body is installed,
At least the lower and upper ends of the lower chain and the upper chain are temporarily fixed to the barge in advance,
First, by pulling at least the mooring rope from the barge to the sea by towing the intermediate portion of the mooring rope with the work boat,
Then, with the temporary anchoring of the upper chain left, the anchor is settled on the seabed and the lower chain is temporarily anchored so that the mooring rope is anchored by the anchor via the lower chain. Release the stopper and drop the anchor from the barge into the sea, then release the temporary fix on the upper end side of the lower chain, pull out the entire lower chain from the barge to the sea,
Thereafter, the main body of the floating reef is moved from the barge to the sea, the temporary fixing of the upper chain is released, the upper chain is pulled out of the barge to the sea, and the main body of the floating reef is moored from the seabed with the mooring line. Floating reef installation and construction method.   2. The method according to claim 1, wherein an intermediate portion of the mooring rope and the work boat are connected by a towing rope at least when the mooring rope is drawn from the barge to the sea.   3. The mooring rope according to claim 1, wherein the upper rope having a high specific gravity capable of sinking in the sea and the lower rope having a low specific gravity capable of floating in the sea are connected in series. 4. Floating fish reef installation and construction method.   The installation of a floating reef according to claim 3, wherein the lower rope is longer than the upper rope, and the work boat towing an intermediate portion of the mooring rope tow the lower rope. Construction method.

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