JPH07247529A - Cable installation method - Google Patents

Abstract

PURPOSE:To protect a cable from being damaged and prevent local bending deterioration by supporting a cable which connects a float to an anchor with the float and a holding rope and spreading the cable on the water surface and then separating the float and forcing the float to sink with a parachute. CONSTITUTION:The tip of a cable 6 wound around a reel on a barge 12 is connected to a float 1 connected to an engagement unit 36 installed on a power boat 35. While the float 1 is being towed with the power boat 35, a floating substance 32, which lets through a holding rope 34 whose one end is fixed with the cable 6, is wound up around the reel one after another. Since the cable 6 is supported with a large number of floating substances 32 on a water surface, no heavy load is applied to the cable 6. An anchor 26 and a proper number of parachutes 38 are mounted to a terminal end of the cable 6 and the cable 6 is suspended in water with a crane 37 and then when the holding rope 34 is released from the engagement unit 36 and pulled to the barge from above, the cable 6 is separated from the floating substances 32 one by another from the side of the float 1 and gradually sinks while bending under the resistance from the parachute 38 until the anchor 26 reached the bottom of the sea. The floating substances 32 are collected as occasion demands and used once again.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for laying a super heavy cable on a water bottom, such as laying a cable between a buoy and an anchor on the sea floor when a buoy is installed at a predetermined position on the sea.

[0002]

2. Description of the Related Art In order to moor a floating body such as a buoy on the sea at a predetermined position, as shown in FIG.
It has a mooring structure in which it is connected by a cable 106 having 04 and 105. At this time, for the floating body 101,
The weight of the cable 106 in water and the water flow F act in the direction of sinking the floating body 101, and the cable 106 is also subjected to its own weight and the tensile force due to the water flow F.

The cable 106 receives the above-mentioned force in the erected state and, for example, in order to moor the floating body 101 at a location at a water depth of 1300 m, it is necessary to use the cable 106 having sufficiently high strength to withstand the tensile load. There is. As a result, the cable alone reached nearly 10 tons,
When the weight of other parts is added, the weight becomes extremely large. For such a floating facility,
As shown in FIG.
A reel 110 around which various facility equipment and cables 106 are wound, and a pontoon 111 on which a floating body, an anchor, and the like are mounted are transported by a power ship 112 to a predetermined position where the floating body is installed. At the predetermined position, the anchor 103 is connected to the socket 105 at the end of the cable 106 supported by the uncoiler 108, and the anchor 103 is connected to the crane 107.
To put it in water.

The state of the cable 106 at this time is shown in FIG.
As shown in, by gradually releasing the reel 110 supported by the unclealer 108 while being guided by the freely rotating cylindrical roller 113 provided at the end of the pontoon 111, the weight of the anchor and the cable causes The cable 106 is paid out from the reel 110, and the anchor 103
Reaches the bottom of the water. After that, the bottom of the floating body 101 is connected to the socket 104 at the upper end of the cable 106, and the facility for the floating body is completed.

[0005]

In constructing a cable for mooring a floating body in a facility for a floating body as described above, an anchor having an extremely large weight and the self-weight of a long cable, which requires sufficient strength, are used. A large force acts on the cable 106 fed out from the uncoiler 108. In particular, as shown in FIG. 11C, the reel 1 supported by the unloader 108 is connected to the cable 1
At the reel outlet 114 through which 06 is delivered, and the contact portion between the roller 113 that guides the cable 106 and the cable, there is a bend in the state where a large tensile force is applied to the cable. Therefore, the supporting force Q1 acts on the reel outlet 114, and the supporting force Q2 acts on the roller 113. Since each supporting force is an extremely large force, the wire of the cable 106 is large at the bent portion. It could be damaged by force. Also, the cable 10
The large force acting on the reel 6 acts on the reel 110 in the direction M of the arrow in the drawing, and the reeler 1
08 can not withstand this force, and at high speed the cable 1
There were times when I rolled out 06.

Therefore, according to the present invention, when a cable is erected, especially when the cable is unfolded and sunk, the cable is prevented from being damaged or the local bending is deteriorated without applying a large load to the cable, thereby extending the service life of the cable. It is an object of the present invention to provide a method for constructing such a cable.

[0007]

In order to solve the above-mentioned problems, the present invention according to claim 1 supports a cable by a float and a holding member when the cable is installed in water.
The cable is separated from the float and submerged in water after the cable is deployed on the water surface. The invention according to claim 2 is the invention according to claim 1, wherein a holding rope is wound around the cable as a holding member and supported. The invention according to claim 3 is the invention according to claim 1 in which the connecting ropes for supporting the floats at equal intervals are attached to the float. In the invention described in claim 4, in the invention described in claim 1, a hook provided with a holding rope can be attached to the float with one touch, the holding rope is hung on the hook, and the cable is wound around and supported, and the hook is expanded on the water surface. According to a fifth aspect of the present invention, in the invention according to the first aspect, a hook is attached to the float, and a knotted loop rope through which a cable is inserted is hooked for each hook to support the float at equal intervals. rope The holding rope as a holding member is developed so as to be substantially parallel to each other. In the invention according to claim 6, in the invention according to claim 1, the anchor side of the cable in which the floating body and the anchor are connected to both ends is provided. The parachute is attached and the anchor is sunk. The invention according to claim 7 is the invention according to claim 1 above.
A cable for connecting a floating body and an anchor to both ends of the cable is attached with a sinking rope having hooks at a predetermined pitch on the anchor side, and the anchors are sinked while sequentially supporting the hooks.

[0008]

Since the present invention is configured as described above, when the long cable is submerged in water, when the cable is separated from the float after the cable is expanded on the water surface while being supported by the float and the holding member. The cable is submerged without any local bends and thus with no local stress. At that time, the floating body is supported by winding a holding rope around the cable, or the floating rope is attached by a connecting rope that supports the floating body at equal intervals, or the holding rope is attached to the holding rope by a hook provided on the floating body. Wrap with a hook, wrap the supporting rope around the cable and support it, and deploy it on the water surface, or take the hook with the connecting loop rope on the float and insert the cable into this connecting loop rope to form the connecting rope. With the floats supported at equal intervals, the cable is deployed on the water surface, and at this time, the connecting member and the holding rope as the holding member are substantially parallel to each other, or one end of the cable deployed on the water surface is floated. Connected,
When the anchor side is sunk while the other end is connected to the anchor, the parachute attached to the anchor side opens and the anchor and the cable are gradually sunk, or one end of the cable deployed on the water surface is connected to the floating body, When the end is connected to the anchor and the anchor side is sunk, the anchor and the cable are gradually sunk by sequentially supporting the hooks of the sloping rope attached to the anchor side from the lower side.

[0009]

Embodiments of the present invention will be described with reference to the drawings. The cable erection method according to the present invention, as shown in the prior art in FIGS. 9, 10 and 11, when connecting a floating body such as a buoy to a predetermined position on the water surface, connects the floating body and the anchor on the seabed. A description will be given of what is applied to the embodiment of erection of a ship, which is equipped with an unloader and a crane as described above, and a pontoon on which a cable wound around a reel and a floating body and other facility equipment are mounted. Transport it in place.

From this state, as shown in FIG.
The through hole 3 of the connecting portion 2 provided at the bottom of the floating body 1 such as a buoy and the through hole 8 of the first socket 7 provided at the tip of the cable wound around the reel 5 supported by the uncoiler 4 are aligned. Then, the pin 10 is inserted into both the through holes 3 and 8, and the nut 11 is screwed into the threaded portion at the end of the pin 10 to connect the floating body 1 and the tip of the cable 6 on the pedestal 12. . At this time, the rollers 13 are appropriately arranged in order to prevent damage due to sliding contact between the cable delivered from the reel 5 and the pier.

As shown in FIG. 2, the cable 6 used here has a first socket 7 and a second socket 14 at both ends of the cable 6, and pins 15 and 16 provided on each socket serve to float and The cable can be connected to the anchor, and the internal structure of the cable is, as shown in Fig. 2 (a), a spiral rope 17 in which a grease-based rust preventive material is enclosed and covered with a polyethylene resin covering material 18. ing. When installing a floating body at a water depth of 1300 m, the cable connecting the bottom of the water and the anchor is tilted at 71 degrees, so the length is long enough to accommodate it and the resistance of the water flow and the tensile load due to the cable's own weight. A cable capable of handling the above is required. For that purpose, a tensile load of 126 tons and a cable diameter of about 38 mm are used, and the covering material 18 having a thickness of about 6 mm is used.

When connecting the floating body and the anchor, the cable 6 is arranged in the intermediate portion as shown in FIG. 3, rather than simply connecting by the cable as described above.
At both ends, the first socket 7 is connected to the first swivel 7 for free rotation, the second socket 21 is connected to the second swivel 22 for free rotation, and the first swivel 20 is connected via the first chain 23. Connected to the floating body 1, the second swivel 22
It is preferable to adopt a connecting structure for connecting to the anchor 26 that is dropped on the seabed 25 via the second chain 24. The chain used at this time has a unit weight of 84 kg /
m, tensile load of 300 tons, total weight 5
It becomes 0 tons.

The chains 23 and 24 used here are
It has the structure shown in FIG. 4, and is used by connecting it at an appropriate position using a connecting shackle 27. Also, swivel 20,
22 has the structure shown in FIG. 5, and has connecting portions 28, 2 at both ends.
9 and a rotating unit 30 in the middle thereof. The rotating part 30 is a sealed type with bearings and has a tensile load resistance of 13
Uses about 0 tons.

Regarding the facility of the floating body, as shown in FIG.
As shown in FIG. 6, from the state in which the cable 6 is connected to the floating body via the first socket 7, as shown in detail in FIG. Through hole 3 of floating body 32 with buoyancy of 50 kg
3 has a holding rope 34 having a diameter of about 12 mm as a holding member.
1B, one end of the holding rope 34 is extended and fixed to the locking portion 36 of the power ship 35. The locking portion 36 is connected to the floating body 1 by the rope 39. There is. Then, when the power ship 35 is made to travel, the floating body 1 is pulled by the rope 39, and the holding rope 34 is also pulled.
Along with that, the cable 6 is pulled, and the cable 6 of the reel 5 is paid out. Cable 5 from reel 5 at this time
Since the force to be delivered is a force that is simply pulled by the power ship and is in the horizontal direction, it does not impose a large load on the cable.

When the cable 6 is unwound from the reel 5 in this manner, the holding rope 34 inserted into the float 32 as described above is wound around the cable 6. As a result, the cable 6 expanding from the barge 12 to the water surface 31 is shown in FIG.
As shown in (a), the water surface 31
It will be supported above. When the connecting portion 27 of the anchor 26 is connected to the second socket 14 provided at the end of the cable 6 and the floating body 1 is connected to the first socket 7 even if the cable 6 of a predetermined length reaches the end. Similar to pin 35
Connect by. At this time, the crane 37 on the barge 12
With this, the rear end of the holding rope 34, which is connected while the anchor 26 is supported, and through which a large number of floats 32 are inserted and which is entangled with the cable 6, is fixed to the ship 12.

Next, as shown in FIG. 1D, the second socket 14 at the tip of the cable 6 or the anchor 26.
An appropriate number of parachutes 38 having a diameter of 3 m are attached to the connecting portion 27 of. Next, the connection between the holding rope 34 and the power ship 35 is released by the locking portion 36. After that, the anchor 26 on the ship 12 is suspended in the water by the crane 37. At this time, when the holding rope 34 is pulled on the pontoon 12, the holding rope 34 is sequentially pulled out from the through hole 33 of the floating body 32, whereby the cable 6 gradually descends from the floating body 1 side. Pier 1
When the anchor 26 suspended in the water while being supported by the rope 40 from 2 gradually descends, the parachute 38 receives the water and opens like 38 '. After that, the rope 40 is separated, and the anchor 26 sinks at a speed of about 1 m / sec due to the large resistance of the parachute 38 against the drop of the anchor 26 and the cable 6 due to its own weight. At this time, all the holding ropes 34 are wound up on the ship 12. The float 32, which is free to float away from the holding rope 34, is collected and reused as needed.

As described above, initially, the cable 6 which is developed in a substantially straight line on the water surface by the holding rope 34 provided with the float 32 loses its support due to the withdrawal of the holding rope 34 and gradually bends while descending. When the parachute 38 opens due to the anchor 26 descending in water, the large resistance of the parachute causes the anchor 26 and the cable 6 to move.
Gradually descends and the cable is erected without significant load. This erected state is shown as an anchor 26 ″ on the water bottom 25 in FIG.
Although the swivel and the chain are not provided at both ends of the cable 6 in the above embodiment, it is preferable to appropriately use these parts as described above and as shown in FIG. At this time, the above-mentioned cable construction method can be applied in exactly the same manner.

As means for providing the float to the holding cable, the means shown in FIG. 6B can be used in addition to the above-mentioned embodiment. That is, the floating object 40 is provided with the first through hole 41 through which the holding rope 34 is inserted and the second through hole 43 through which the connecting rope 42 is inserted. At the time of use, the holding rope 34 is inserted into the first through hole 41 of the float 40 while being wound around the cable 6 as in the above embodiment, and at the same time, the connecting rope 42 is inserted into the second through hole 43 of the float 40. Then, the stopper 44 is fixed near the outlet end. By repeating this operation, the floats 40 are attached to the cable 6 at substantially equal intervals as shown in FIG. When the holding rope 34 is pulled out from the floating object 40, if the connecting rope 42 is pulled from the power ship side, the floating object 40 will be fixed linearly.
However, it does not move by being dragged by the holding rope 34 and can be reliably pulled out from the floating object at a predetermined position, and after all the holding ropes 34 have been pulled out, the connecting rope 42 is pulled from the berth side or the power vessel side. By doing so, all the floats are recovered.

As means for providing a float on the holding cable,
The means of the embodiment shown in FIG. 6C can also be adopted. That is, without using a through hole for inserting the holding rope in the floating body 45, only the through hole 46 for inserting the connecting rope 46 is provided, and the ring 4 clamped and fixed to the outer periphery of the cylindrical floating body 45.
Fix the hook 48 to 7. The opening 49 of this hook 48
Is provided with a stopper 50 which is constantly urged in a direction to close the opening 49 from the inside to the outside of the opening 49 so as to be swingable around a shaft 51, whereby the hook 48 is provided.
Only pushes the holding rope 34 from the outside of the opening 49 to the end and swings the stopper 50 inward to open the opening 49.
Open, and the inside of the hook 48 is opened, and at the same time, the stopper 50 closes the opening 49 again, and thereafter, the holding rope 34 cannot come out only by pressing the stopper 50 from the inside, and the Hook 48
Open the stopper 4 only by pushing the stopper 50 from the outside.
9 is released, and the holding rope 34 comes off. Such a hook is commonly called a one-touch type hook, and is widely used. Here, those hooks having appropriate sizes are adopted. A stopper 44 is provided on the connecting rope 42 as in the embodiment shown in FIG. In this embodiment, the holding rope 34 is attached to the floating body 40.
Since the work of inserting it through the through hole is not necessary and the float 45 can be attached to the holding rope 34 with one touch, the work can be facilitated.

The means of the embodiment shown in FIG. 6D can also be adopted as means for providing the floating cable to the holding cable.
That is, as in the embodiment shown in FIG. 6C, the float 45 has only the through hole 46 through which the connecting rope 42 is inserted, and the rope 53 wound around and fixed around the through hole 46 has the same one-touch type as described above. Hang the hook 48. On the other hand, the holding rope 34 has
The ring-shaped holding rope 54 is appropriately fixed, and when the cable 6 is deployed on the water surface, the cable 6 is passed through the ring-shaped holding rope 54 and the ring-shaped holding rope 54 is hung on the one-touch hook 48. Thereby, the connecting rope 42 is arranged in parallel with the holding rope 34. Further, when the holding rope 34 is pulled out, the floating rope 45 is pulled in the same direction via the floating ring-shaped holding rope 54 and the one-touch type hook 48 by pulling the holding rope 34, and is collected.

At this time, the connecting rope 42 can be pulled alone or simultaneously with the holding rope. Also,
The cable 6 may be supported only by the ring-shaped holding rope 54 without using the holding rope 34. At this time, the ring-shaped holding rope 54 is pulled by pulling the connecting rope 42.
Can be removed from the cable 6. At this time,
As shown in FIG. 6 (e), instead of the ring-shaped holding rope 54, a holding rope 56 having retaining rings 55 at both ends is used. It is also possible to form something similar to a rope. Also in this case, when pulling out the holding rope 56, it can be pulled out by pulling the connecting rope 42.

In the above embodiment, an example in which a floating body such as a buoy is installed is shown, but in addition to this, the present invention can be applied when a cable is installed in water at the time of installation or construction of various objects. At that time, as shown in FIG. 7 (a), the cable 6 is pulled out from the pontoon 12 by the power ship 35, and at that time, the float 32 and the holding rope 34 are used to lift the cable 6 above the water surface 31 as in the above embodiment. The cable 7 is unfolded while floating, and the sockets 7 and 14 at both ends of the cable 6 are supported by the carrier 12 and the power ship, respectively. Then
By disconnecting the holding rope 34 from the power ship 35 side and pulling in the holding rope 34, the cable 6 is moved to the position shown in FIG.
As shown in FIG. 2, it can be stretched over the sea with both ends being supported, and it can be applied to various works such as attaching various members to both ends or connecting with other cables.

On the other hand, the means shown in FIG. 8 can be adopted as means for gradually lowering the end portion of the cable stretched on the water surface to the water bottom. That is, after the cable is unfolded on the water surface by the means shown in each of the above-mentioned embodiments, the sinking rope 60 is fixed to the second socket 14 side of the cable 6. A large number of rope hooks 61 are fixed to the sinking rope 60 by clamp rings 62 at appropriate intervals, as shown in FIG. The sinking rope 60 should be at least longer than the water depth. Crane 3 on the ship 12
Two crane rope actuating devices are provided at the tip of the arm 63 of No. 6, and crane ropes 64 and 65 are provided on each of them.

When the cable end is sunk, the rope hook 61 is hooked on the hook 66 of the crane rope 64 on one side and gradually lowered. At this time, the subsequent rope hook 61 is hung on the hook 67 of the crane rope 65 on the other side and kept at a predetermined height. When the hook 66 of the crane rope 64 on one side falls below the predetermined sinking pitch P. The descent of the sinking rope 60 is stopped by the hook 61 hung on the hook 67 of the crane rope 65 on the other side, and the hook 66 of the crane rope 64 on one side is disengaged from the rope hook 61. Then, the crane rope 65 on the other side is gradually lowered. This time,
The hook 66 of the crane rope 64 on one side is hooked on the succeeding rope hook 61 to raise it to a predetermined height. Or later,
By repeating the same operation, the end of the cable 6 gradually descends and reaches the water bottom 25. After the completion of the work, the sunk rope may be cut off, or the metal fitting for holding the socket 14 may be detached when no load is applied at the time of bottoming.

The float used in the above-mentioned various embodiments may be made of polystyrene foam, or may be a plastic tube filled with air and wound around a cable. You can reduce it. Further, the holding rope can be automatically cut by an additional load when the cable is settled.

Various cables, chains, and anchors can be used for the above-mentioned various embodiments, and for example, those shown in the following [Table 1] can be adopted.

[0027]

[Table 1]

[0028]

EFFECTS OF THE INVENTION Since the present invention is constructed as described above, the weight of the cable is dispersed on the surface of the water, an excessive rotational force is not generated on the reel, and the cable is not damaged by the local intermediate support. Local bending deterioration can be prevented in advance.

Further, since the floating body of the cable can be easily removed by pulling the holding rope, the influence of the floating body due to the water flow can be eliminated.

Further, after the cable is unfolded on the water surface, the buoyancy of the float is adjusted while the cable is tensioned in the horizontal direction, or the cable is sunk by reducing the sinking speed by the water resistance of the parachute, or at a predetermined pitch. By supporting the hooks in order by using the sunk rope equipped with the hooks and sunk, the cable can be prevented from shock damage and the life can be extended.

[Brief description of drawings]

FIG. 1 is a side view for sequentially explaining an outline of a cable erection method in an embodiment of the present invention based on (A) to (D).

FIG. 2 shows a cable used in an embodiment of the present invention,
(A) is a sectional view, (B) is a plan view, and (C) is a side view.

FIG. 3 is a side view showing a cable installation state according to the embodiment of the present invention.

FIG. 4 shows a chain used when constructing the cable,
(A) is a plan view and (B) is a side view.

FIG. 5 shows a swivel used when constructing the cable,
(A) is a plan view and (B) is a front view.

FIG. 6 shows various embodiments of cable support by a float according to the present invention, (a) is a perspective view of the embodiment shown in FIG. 1,
(B) is a perspective view of another embodiment, (C) is a perspective view of yet another embodiment, (D) is a perspective view of yet another embodiment, and (E) is one of the embodiments of (D). It is a perspective view showing a part modification.

FIG. 7 shows an embodiment in which the cable erection method of the present invention is used for various works, (a) is a side view showing a state in which the cable is supported by a floating body, and (b) is a part of the floating body supporting the cable. It is a side view showing the state where it was separated from the cable.

FIG. 8 shows another embodiment of the present invention, (A) is a side view showing an overall outline, and (B) is a partial side view thereof.

FIG. 9 is a side view showing an overall outline of mooring of a floating body to which the cable erection method of the present invention is applied.

FIG. 10 is a perspective view showing a state in which the cable is conveyed to a predetermined position on the water when the cable is installed.

FIG. 11 shows a conventional cable erection method, in which (a) is a partial plan view thereof, (b) is a side view thereof, and (c) is an enlarged side view of the same portion.

[Explanation of symbols]

1 ... Floating body, 4 ... Unreira, 5
…… Reel 6 …… Cable, 7 …… Socket, 1
2 ... Boat 14 ... Socket, 20 ... Swivel, 2
2 ... Swivel 26 ... Anchor, 32 ... Float, 3
4 ... Holding rope 35 ... Power ship

Claims (7)

[Claims] 1. An installation of a cable, characterized in that, when the cable is submerged in water, the cable is supported by a float and a holding member, and after being expanded on the water surface, the cable is separated from the float and submerged in water. Method. 2. The cable erection method according to claim 1, wherein a holding rope as a holding member is wound around and supported on the cable and is spread on the water surface. 3. The cable erection method according to claim 1, wherein the floating ropes are provided with connecting ropes for supporting the floating bodies at equal intervals. 4. The cable according to claim 1, wherein the float is provided with a hook to which the holding rope can be attached with one touch, the holding rope is hung on the hook, and the cable is wound around and supported by the hook, and the hook is unfolded on the water surface. . 5. A hook is attached to a floating body, and a hook and loop rope for inserting a cable is hooked for each hook, and a connecting rope for supporting the floating body at equal intervals and a holding rope as a holding member are substantially parallel to each other. The method for constructing a cable according to claim 1, wherein the cable is laid as follows. 6. The cable erection method according to claim 1, wherein a parachute is attached to the anchor side of the cable in which the floating body and the anchor are connected to both ends, and the anchor is sunk. 7. A cable for connecting a floating body and an anchor to both ends of the cable is provided with a sinking rope provided with a hook at a predetermined pitch on the anchor side, and the anchor is sinked while sequentially supporting the hook. The cable installation method described in 1.