JP2002281626A - Boat for laying submarine long material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a boat for laying a submarine long material which prevents size enlargement and weight increase of brake device for controlling the speed of forcing down a submarine long material into the sea, and arranges the side pressure added to the brake device to not to be excessive. SOLUTION: In the board for laying a submarine long material, which is equipped with a long material storage for storing a pipe 12 for water-intake being the submarine long material, a brake device for controlling the speed of letting down the pipe 12 for water-intake into the sea, and a shooter 20 for letting down the pipe 12 for water-intake, the sliding face 20a in contact with the pipe 12 for water-intake of the above shooter 20 is provided with a high frictional resistance layer 22 for increasing the frictional resistance with the pipe 12 for water-intake.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a submersible elongate body such as a submarine water pipe, a submarine oil supply pipe, a fluid transport pipe such as a seawater intake pipe, and a submarine cable or the like for power and communication (including optical communication). The present invention relates to a seabed laid long body laid boat for laying (including burying) on the seabed.

[0002]

2. Description of the Related Art A conventional submarine laid long body laying boat comprises a long body storage section for storing a submarine laid long body, a brake device for controlling a speed at which the submarine laid long body is dropped into the sea, and a submarine laid. It has a shooter that drops a long body into the sea. Then, when laying a submarine laid long body on the seabed using this laid boat, a laid boat previously storing the submarine laid long body in the long body storage section is provided along the predetermined laying route on the sea. Towing by tugboat. At the same time, the submarine laid elongate body is pulled out from the elongate body storage part, dropped into the sea from the stern or bow of the laid boat by a chute while being controlled to a predetermined drop speed by a brake device, and laid on the seabed. . The submarine laid long body laid on the seabed is buried on the seabed as needed.

[0003] By the way, a chute used for dropping a submarine laid long body from a laid boat into the sea is required to maintain the submarine laid long body at an allowable radius of curvature or more when dropping the submarine laid long body into the sea. This is an indispensable device to suppress the lateral pressure applied to the laid long body to the allowable lateral pressure or less.
Then, the friction coefficient of the sliding surface in contact with the submarine laid long body is reduced, the friction resistance with the submarine laid long body is reduced, and a large brake is applied to the submarine laid long body that passes through the chute and falls into the sea. In order to prevent the force from acting, the submarine laid long body is dropped into the sea.

[0004] Further, a control force required for a brake device for controlling the speed of dropping the submarine laid long body into the sea, that is, a braking force F, depends on the laying depth h of the submarine laid long body laid on the seabed. If the frictional resistance received from the chute when the submarine laid long body passes through the chute largely depends on the underwater weight W per unit length of the submarine laid long body, the following equation (1) is obtained. Relationship.

[0005]

## EQU1 ## F = Wh (1)

Accordingly, as the installation water depth h of the long seabed installation body increases, the braking force F required for the braking device increases.

[0007]

In recent years, the development and utilization of deep ocean water with relatively good water quality, high nutrient content, and low temperature in various places have been advanced, and this deep water is pumped up to sea or land for transportation. There is a tendency that the water depth of the water intake pipes used for the installation on the seabed is rapidly increased. In the case of laying an intake pipe on the seabed in such a deep sea area, the weight of the intake pipe to be supported by the stern or bow of the laid vessel increases at the time of the installation, so that the weight of this underwater weight is increased. Most of them need to be supported by a brake device, and in this brake device, the braking force required to control the speed at which the intake pipe is dropped from the laid boat into the sea becomes extremely large. In this case, it is necessary to increase the power for driving the brake device and the mechanical strength of each mechanism, and there is a problem that the brake device becomes large, heavy, and causes a significant increase in cost.

Further, the gripping force for gripping the water intake pipe by the brake device naturally increases, and a large lateral pressure exceeding the allowable side pressure is applied to the hollow water intake pipe, and the hollow water intake pipe is compressed and buckled. There was also a risk of destruction.

[0009] Such a problem also occurs when a fluid transport pipe such as a submarine water supply pipe or an oil supply pipe, which is a long submarine laying body other than the above-mentioned intake pipe, is laid on the seabed in a deep sea area.
Furthermore, the submarine laid long body other than the fluid transport pipe, for example, when laying a submarine cable on the seabed, although the case of the water intake pipe, there are few cases laid on the seabed in a deep sea area, Since the underwater weight per unit length is generally larger than the water intake pipe, when the laying water depth becomes slightly deeper, the braking force required for the drive control of the brake device also increases, and the brake device is large. In addition to increasing the weight and increasing the cost, the submarine cable may be subjected to excessive lateral pressure exceeding the allowable lateral pressure, and the submarine cable may be deformed or damaged, thereby deteriorating the electrical characteristics and signal transmission characteristics.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and it is possible to prevent a brake device for controlling the speed of dropping a submarine laid long body into the sea from becoming large and heavy, and
It is an object of the present invention to provide a submarine laid long body laid boat in which side pressure applied to a brake device is not excessively increased.

[0011]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention controls a long body storage section for storing a long seafloor laid body and a speed of dropping the long seafloor laid into the sea. In a submarine laid long body laying boat equipped with a brake device and a shooter for dropping the submarine laid long body into the sea, a sliding surface of the chute that comes into contact with the submarine laid long body has friction with the submarine laid long body. It is characterized in that a high friction resistance layer for increasing resistance is provided.

According to the above construction, the submarine laid long body which is dropped into the sea while sliding on the sliding surface of the chute from the laying ship via the brake device is provided with a frictional resistance provided by the high frictional resistance layer provided on the sliding surface of the chute. By this action, a large braking force acts to lift the submarine laid long body in the direction opposite to the direction in which it is dropped into the sea. Then, even if the underwater weight of the submarine laid long body increases at the time of laying, the underwater weight of the submarine laid long body will be supported not only by the brake device but also by the shooter,
The braking force required to control the speed at which the submarine laid long body is dropped into the sea by the brake device is reduced. Therefore, the power for driving and controlling the brake device and the mechanical strength of each mechanism can be reduced, and the size, weight, and cost of the brake device can be reduced.

Further, when the braking force required by the brake device is reduced, the gripping force of the long submarine laid body is inevitably reduced, and excessive lateral pressure exceeding the allowable side pressure does not act on the long submarine laid body. When laying a long body under the sea floor,
The submarine laid long body does not cause buckling breakage, deformation or damage, and the submarine laid long body can be safely laid on the seabed in a deep sea area.

[0014] In the submarine laid long body laying ship of the present invention, the submarine laid long body laid on the seabed is laid as a high frictional resistance layer provided on a sliding surface of the chute which is in contact with the seabed laid long body. The friction coefficient may have directionality so that the frictional resistance in the direction of pulling up to the ship is smaller than the frictional resistance in the direction of dropping the submarine laid long body from the laid boat into the sea.

As described above, when the friction coefficient of the high frictional resistance layer is made directional, the long submarine laid on the seabed may be damaged by anchoring or the like, and may be pulled up on a laid ship for repair. In addition, since the frictional resistance of the chute in the direction in which the elongate submarine laid body is lifted is reduced, the take-up force required to lift the elongate submarine laid body can be reduced. Therefore, it is possible to reduce the size of the facility for winding and recovering the long submarine laid body provided on the laid ship, thereby reducing the cost of the recovery facility, and adding the frictional resistance of the shooter to the long laid submarine floor. This is preferable because the taking-up force of the body is increased, and there is no danger of the seabed laid long body being damaged during collection.

Further, in the present invention, in order to give directionality to the friction coefficient of the high frictional resistance layer, the contact surface of the resistance layer with the submarine laid long body is dropped or the submarine laid long body is dropped. A plurality of projections having a trapezoidal cross section are provided along the lifting direction, and the length of the inclined side of the projection located above the shooter is formed to be shorter than the length of the inclined side located below the shooter. Is also good.

[0017]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a schematic diagram showing a state in which a seabed laid long body, for example, a deep seawater intake pipe 12 is laid on a seabed 14 using a seabed laid long body laying boat 10 of the present invention. . The submarine laid long body laying boat 10 shown in this figure is a long body in which the water intake pipe 12 is wound and wound in a coil form on a turntable or a drum installed on the laying boat or inside the boat, or on a laying boat or inside the boat. The storage unit 16 includes a storage device 16, a brake device 18 such as a caterpillar for controlling the speed of dropping the water intake pipe 12 into the sea, and a shooter 20 serving as a guide for dropping the water intake pipe 12 into the sea.

As shown in FIGS. 2A and 2B, the shooter 20 has a gutter shape (bend type) having a U-shaped cross section with an opening facing upward and a 1/4 circular shape in the length direction. The main body is made of a metal material such as mild steel and stainless steel.
Then, as shown in FIG.
Or it is installed at the bow (not shown). This shooter 20
The inner bottom surface is a sliding surface 20a for guiding while sliding in contact with the intake pipe 12 and dropping it into the sea,
In order to prevent excessive bending from being applied to the water intake pipe 12, the intake pipe 12 is formed to have an allowable curvature radius or more and be curved outward with a constant curvature radius.

The long laying ship 10 of the present invention is characterized in that the sliding surface 20a of the chute 20 is provided with a high friction resistance layer 22 for increasing the friction resistance with the water intake pipe 12. I have. For example, as shown in FIG. 2C, the high frictional resistance layer 22 has a rubber plate-like body (rubber sheet) 24 having a rectangular cross-section curved in an arc shape so as to conform to the shape of the sliding surface 20a. And is provided by attaching the bottom surface to the sliding surface 20a with an adhesive or the like. The rubber plate 24 is made of a rubber material having excellent wear resistance and durability, such as EP rubber, urethane rubber, and polybutadiene rubber. By using a rubber material, the friction coefficient of the contact surface with the water intake pipe 12 increases, and the frictional resistance with the water intake pipe 12 can be increased.

It is to be noted that, when a large number of micro uneven portions 24a as shown in FIG. The friction coefficient of the surface increases, and the friction resistance can be further increased. The coefficient of friction can be adjusted by changing the material of the high frictional resistance layer 22 or the unevenness (rough surface state) of the contact surface of the rubber plate-like body 24, etc., up to a coefficient value of about 1.0. It can also be easily obtained.

As described above, the sliding surface 20a of the shooter 20
By providing a high frictional resistance layer 22 on the water intake pipe 12
Of the water intake pipe 12 at the chute 20 increases when the water falls down into the sea while sliding on the sliding surface 20a.
Since the braking force opposing the drop of the water works, the braking force required by the brake device 18, that is, the braking force that must be applied to the water intake pipe 12 by the device 18 can be reduced and reduced. So shooter 2
The relationship between the friction coefficient on the surface of the high frictional resistance layer 22 (the contact surface with the water intake pipe 12) provided on the 0 sliding surface 20a and the braking force required by the brake device 18 is expressed by the following equation (2). Can be sought.

[0022]

## EQU2 ## T = Wh / e ^μθ (2)

In the above formula (2), T: rear tension on the inlet side of the chute 20 for introducing the intake pipe 12 (= braking force required by the brake device 18) W: unit length of the intake pipe 12 Underwater weight per unit h: Installation water depth μ: Friction coefficient of high frictional resistance layer 22 (when dropping water intake pipe 12 into the sea) θ: Curvature of high frictional resistance layer 22 (π / in FIG. 2)
2)

When a flexible intake pipe 12 having a weight of 50 kg / m in water is laid on the seabed 14 in a sea area at a depth of 100 m, the brake device is set using the friction coefficient μ of the high friction resistance layer 22 as a parameter. Table 1 below shows a trial calculation of the required braking force at 18.

[0025]

[Table 1]

As is clear from the above Table 1, the weight of the water intake pipe 12 under water until it is dropped into the sea and reaches the seabed 14 is not only the brake device 18 but also the shooter 2.
Since it supports even zero, the force for supporting the underwater weight is dispersed, and the braking force required by the brake device 18 can be reduced. Further, by increasing the friction coefficient of the high frictional resistance layer 22, the braking force can be reduced exponentially. For example, when the friction coefficient of the high friction resistance layer 22 is 0.5, the braking force applied by the brake device 18 is reduced to about 1/2 and the friction coefficient is set to 1. In the case of 0, the braking force can be reduced to about 1/5. As a result, even if the water laying depth of the water intake pipe 12 becomes deep and the underwater weight increases, the braking force to be borne by the brake device can be reduced. Therefore, it is possible to reduce the mechanical strength, reduce the size and weight of the brake device, reduce the cost, and reduce the installation cost.

FIG. 4 shows the contact surface between the high frictional resistance layer 22 and the water intake tube 12, that is, the contact surface between the rubber plate 24 constituting the high frictional resistance layer 22 and the water intake tube 12. , The dropping direction or the lifting direction of the intake pipe 12 (FIG. 2).
A plurality of projections 26 each having a trapezoidal cross section are provided continuously along (a), and the length of the inclined side 26a of the projection located above the shooter is determined by the length of the inclined side 26b located below the shooter. The surface is roughened so as to be shorter than the length so that the intake pipe 12 has a reverse direction in the dropping direction and a forward direction in the lifting direction. That is, by providing such projections 26 and roughening the contact surface, the frictional resistance in the direction in which the intake pipe 12 laid on the seabed 14 is lifted to the laying boat 10 for repair or the like is reduced. The friction coefficient of the contact surface of the high friction resistance layer 22 has a direction so as to be smaller than the friction resistance in the direction of dropping the water intake pipe 12 from the laying boat 10 into the sea for laying. is there.

As described above, when the friction coefficient of the high frictional resistance layer 22 is made directional, the water intake pipe 12 laid on the sea floor 14 is damaged by an anchor or the like, and is pulled up on the laying boat 10 for repair. In such a case, the frictional resistance of the shooter 20 in the direction in which the intake pipe 12 is pulled up is reduced.
Is smaller than the frictional resistance in the direction of dropping the water, so that the take-up force required to pull up the water intake pipe 12 can be reduced. Therefore, when the take-up / recovery facility (not shown) for the water intake pipe 12 provided on the laying boat 10 and the long body storage unit 16 also serves as the recovery facility, the storage unit 16 is reduced in weight and size. This makes it possible to reduce the cost of the recovery facility and to reduce the take-up force required to lift the water intake pipe 12, so that the water intake pipe 12 may be excessively stretched or subjected to side pressure during its recovery. It is practical because there is no risk of damage.

When the water intake pipe 12 is laid on the seabed 14 by using the seabed laid long body laying boat 10 of the present invention, as shown in FIG. Is towed by the tugboat 11 along the predetermined laying route on the sea. At the same time, the long body storage unit 1
The stern of the laying boat 10 or the stern of the laying boat 10 is pulled out while pulling out the water intake pipe 12 from the 6 and controlling the dropping speed by applying a predetermined braking force with the brake device 18 and applying frictional resistance in the lifting direction by the shooter 20. It is performed by dropping it from the bow into the sea and laying it on the seabed 14. The water intake pipe 12 laid on the seabed 14 is buried under the seabed simultaneously with or after the laying as required. In addition, the submarine laid long body laid on the seabed 14 by the laying ship 10 of the present invention is not limited to the water intake pipe 12, but can be naturally applied to other fluid transport pipes and submarine cables. It is.

FIGS. 5A and 5B show a shooter 28 having a structure different from that of the shooter 20 shown in FIG. The shooter 28 is composed of a bend pipe having a split structure in which two iron-made semicircular tubular bodies 30 and 30 are divided and combined. The semicircular tubular bodies 30, 30 have mounting flanges 30a, 30a on both side edges, and are 1/4 in the longitudinal direction.
It is formed in a substantially semicircular cross-section that is curved outward and convex so as to have a circular shape and maintain a constant radius of curvature equal to or larger than the allowable radius of curvature. And these semicircular tubular bodies 3
0, 30 are overlapped so that the semi-circular recesses face each other, and the two mounting flanges 30a, 30a are combined by tightening with bolts, and a long seabed laid elongate body such as the water intake pipe 12 is provided at the center. A through hole 32 is provided to pass through. This through hole 32 is 10 to 20% smaller than the outer diameter of the submarine laid long body.
A rubber plate (rubber sheet) having a large inner diameter and forming the high friction resistance layer 22 on the inner peripheral surface, that is, the sliding surface.
24 is lined. The inner peripheral surface of the rubber plate 24, that is,
The surface to be contacted with the submarine laid elongate body may be subjected to the above-mentioned surface roughening treatment, if necessary, to increase the frictional resistance with the submarine laid elongate body.

When such a shooter 28 is used, almost the entire peripheral surface of the long body laid on the seabed can be brought into contact with the high frictional resistance layer 22 of the shooter 28 and dropped into the sea.
Therefore, it is preferable because the frictional resistance when dropping the long seabed laid body can be further increased, the braking force required by the brake device 18 can be reduced, and the burden can be further reduced.

The high friction resistance layer 22 is formed by providing a rubber plate 24 on the sliding surface of the chute 20 or 28, such as the water intake pipe 12 or the like, which is in contact with the long submarine laid long body. In addition, the sliding surface itself is subjected to a surface roughening treatment such as the provision of the fine irregularities 24a and the protrusions 26 having a non-equilateral triangular cross section, as described above, to thereby provide a high friction resistance layer (not shown). ) May be provided.

[0033]

As described above, according to the submarine laid long body laying ship of the present invention, the seabed laid on the sliding surface of the shooter which drops the submarine laid long body into the sea is in contact with the submarine laid long body. Since the high friction resistance layer for increasing the frictional resistance with the elongate body was provided, the installation water depth of the elongate undersea elongate body was deepened, and even when the underwater weight of the elongate undersea elongate body increased during the installation, The underwater weight can be supported by the shooter, and the braking force required by the brake device can be reduced. Therefore, the power for driving and controlling the brake device and the mechanical strength of each mechanism can be reduced, and the size, weight, and cost of the brake device can be reduced.

Further, the gripping force of the submarine laid long body is reduced, and excessive lateral pressure exceeding the allowable side pressure does not act on the submarine laid long body. Buckling failure, deformation or damage does not occur, and the seabed laid long body can be safely laid on the seabed in a deep sea area.

In addition, in the submarine laid long body laying ship of the present invention, the chute is provided with a seabed laid long body laid on the seabed as a high frictional resistance layer provided on a sliding surface in contact with the seabed laid long body. The friction coefficient may have directionality such that the frictional resistance in the direction of lifting the laying boat is lower than the frictional resistance in the direction of dropping the submarine laid long body from the laying boat into the sea. In this case, when the long seabed laid on the seabed is to be lifted on a laid ship for repair or the like, the frictional resistance of the shooter in the direction in which the long seabed laid body is lifted is reduced. The take-up force required for lifting the laid long body can be reduced. Therefore, it is possible to reduce the size of the facility for winding and recovering the long seabed laid on the laid ship, thereby reducing the cost of the recovery equipment and the pulling force required for lifting the long seabed laid body. Therefore, there is no danger of the seabed laid long body being damaged due to excessive stretching or lateral pressure during its recovery.

[Brief description of the drawings]

FIG. 1 is a schematic view showing a use state of a long sea laying boat laid on a seabed according to the present invention.

FIGS. 2A and 2B schematically show a shooter used in a submarine laid long body laid boat of the present invention, wherein FIG. 2A is a front view, FIG. 2B is a right end view, and FIG. It is the front view which expanded the part.

FIG. 3 is an enlarged front view of a part of a modification of the high friction resistance layer of FIG.

FIG. 4 is an enlarged front view of a part of a further modification of the high friction resistance layer of FIG. 2 (c).

FIG. 5 shows an outline of a modified example of a shooter used in a submarine laid long body laid boat of the present invention, wherein (a) is a front view,
(B) is a right end view.

[Explanation of symbols]

 REFERENCE SIGNS LIST 10 Submarine laid long body laid boat 11 Towing boat 12 Intake pipe 14 Seabed 16 Long body storage section 18 Brake device 20 Shooter 20a Running surface 22 High friction resistance layer 24 Rubber plate 24a Micro unevenness 26 Triangular cross section Projector 26a Inclined side 26b Inclined side 28 Shooter 30 Semicircular tubular body 30a Mounting flange 32 Through hole

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H02G 9/02 F16L 1/04 C

Claims (3)

[Claims] An elongate body storage section for storing an elongate submarine laid body, a brake device for controlling a speed at which the elongate submarine laid object is dropped into the sea, and a shooter for dropping the elongate submarine laid body into the sea are provided. In the above-described submarine laid long body laying ship, the chute is provided with a high friction resistance layer for increasing frictional resistance with the submarine laid long body on a sliding surface that comes into contact with the submarine laid long body. A long body laying boat laid on the sea floor. 2. The high frictional resistance layer has a frictional resistance in a direction in which a submarine laid long body laid on the seabed is lifted to the laying boat, and a frictional resistance in a direction in which the submarine laid long body is dropped from the laying boat into the sea. 2. The long marine submarine laying ship according to claim 1, wherein the coefficient of friction has a directivity so that the friction coefficient is also reduced. 3. A plurality of non-equilateral triangular projections are provided on the contact surface of the high frictional resistance layer with the long submarine laid body along the dropping or lifting direction of the submarine laid long body,
2. The submarine laid long body laying ship according to claim 1, wherein the length of the inclined side of the projection located above the chute is shorter than the length of the inclined side located below the chute.