JPS5953770B2 - How to lay a long body on the seabed - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for laying long bodies such as submarine cables and water pipes on the seabed using a laying ship.

When a long body is to be laid on the seabed, a long body coil from which the long body is uncoiled is mounted on a laying ship, and the long body is paid out from this long body coil to carry out the laying work.

In this case, if a very long elongate body is coiled as one coil, the diameter of the elongate body coil will be very large, and a huge laying ship will be required.

To avoid this, usually a long body 1 is
Although the coils are shown as a plurality of coils, the drawings show them as two coils.

), the end of the elongate body 1 of the first elongate body coil 21 and the tip of the elongate body 1 of the second elongate body coil 2° are kept in a continuous state, and these elongate body coils 2 □ , 2□ is mounted on the laying ship 3, and a common sheave 5 is movably installed on this mount 4. Initially, this sheave 5 is placed above the first elongated coil 2. In this state, the long body 1 at the tip of the first long body coil 2□ is raised using the sheave 5 as a guide and guided to the rear of the laying vessel 3, and as the laying vessel 3□ advances. The elongated body 1 was fed out into the sea from the elongated body feeding end 3A at the rear end.

In addition, 6 is a tugboat that pulls the laying boat 3.

In this case, if the sheave 5 is not located directly above the elongated body coil being fed out, the elongated body coil being fed out will collapse and a kink will occur in the elongated body 1.

When the elongated body 1 finishes being fed out from the first elongated body coil 21 and moves on to being fed out from the second elongated body coil 2°, the sheave 5 is placed on top of the second elongated body coil 2 □. I need to move it.

Since the elongated body 1 is fed out at a speed of about 70 m to 120 m per minute, the sheave 5 cannot be moved in accordance with such speed.

For this reason, conventionally, the laying ship 3 was temporarily stopped and moored with an anchor, and the sheave 5 was moved.

However, such a laying method has the disadvantage of poor laying efficiency.

In addition, with such a laying method, the laying ship 3 may not be able to be moored unless it is accurately guided to the mooring point, or the laying ship 3 may not be able to moor.
The disadvantage was that the work could be dangerous due to water being washed away.

An object of the present invention is to provide a seabed long body that can continue laying a long body without stopping the laying vessel when transferring the long body from one long body coil mounted on the laying vessel to the next long body coil. To provide installation methods.

Hereinafter, specific examples of the present invention will be described in detail with reference to the drawings.

As shown in FIG. 2, in this embodiment, the first,
The second elongated body coils 2□, 22 are arranged such that the one with the smallest number is located on the side closer to the elongated body feeding end 3A of the installation ship 3, and the one with the largest number is located at the elongated body feeding end. They are mounted in alignment in the longitudinal direction of the laying ship 3 so as to be located on the far side from the section 3A.

The length of the first long body coil 2 □ with the smaller number among these long body coils 21, 2° and the length of the long body coil 2 □ with the larger number next to the end side of the long body 1 The distal end side of the ulnar body 1 is in a continuous state.

A frame 4 is mounted on the laying ship 3, and the first and second sheaves 5□, 5□ are supported on the frame 4 in correspondence with the upper parts of the first and second long body coils 2□, 22. It is set in place.

In this case, each sheave 50, 5□ has a semicircular shape.

The elongated body 1 of the second elongated body coil 2° with the larger number rises from the far side with respect to the first sheave 5 toward the second sheave 5□ above it. The hook passes over the sheave 5° and descends from the side closest to the first sheave 5□, and then connects it to the end of the elongated body 1 of the first elongated body coil 2 with the smaller number next to it. I'm trying to connect.

The elongated body 1 of the first elongated body coil 2□ rises from the side close to the second sheave 5□ toward the first sheave 5□ above it, and rises above this first sheave 5□. The hook is extended so as to pass through and reach the elongated body delivery end 3A at the rear end of the laying vessel 3.

In this state, while moving the laying ship 3 to the left in FIG. 2, the elongated body 1 is initially paid out from the first elongated body coil 2□ to carry out the laying work.

When the elongated body 1 has been fed out from the first elongated body coil 2 □, the end of the elongated body 1 of the first elongated body coil 2 □ and the long length of the second elongated body coil 2 □ Since it is continuous with the tip of the body 1, the feeding of the elongate body 1 automatically moves to the second elongate body coil 2° side.

At this time, since the elongated body 1 is passed in a special way as described above, the elongated body 1 paid out from the second elongated body coil 2 □ is directed toward the second sheave 52. First sheave 5
1 rises from the far side from the side, passes over this second sheave 5°, then passes over the first sheave 5□, and is fed out to the long body feeding end 3A side at the rear end of the laying ship 3. Ru.

Therefore, it is possible to automatically shift the feeding of the elongate body 1 from the first elongate body coil 2□ to the second elongate body coil 2□ without stopping the laying ship 3.

In addition, each long body coil 21.2 is
If the two elongated bodies are not in a continuous state with each other,
After coiling the long body coils 2□, 22 on the laying ship 3, the end of the long body coil 21 and the tip of the long body coil 22 are connected in a continuous state, and then this long body 1 is placed in a sheave. You may pass the hook to 5□, or pass the long body 1 on the long body coil 2□ side to the sheave 52, and then pass both coils 2□, 2.
Two elongated bodies 1 may be connected in a continuous state.

The present invention is not applied only to the case of the first and second elongated body coils, but also to the case where the first to nth (n is an integer of 2 or more) elongated body coils are used in the longitudinal direction of the laying ship. Even when the sheaves are aligned and mounted, the first to nth sheaves are fixed on top of the elongated body 1 extending from the second elongated body coil 2 □ in Fig. 2. Kake can be applied in the same way by sequentially performing the transfer method.

In the above embodiment, a case has been described in which the elongated body 1 is paid out from the rear of the laying ship 3. However, the present invention is not limited to this, and in FIG. The present invention can be similarly applied to the case where the installation ship 3 moves rightward in the drawing and the elongated body 1 is fed out from the front part of the installation ship 3.

In this case, the long body 1 fed out from the front part of the laying ship 3 turns at the front part of the laying ship 3 and passes under the laying ship 3.
It will head toward the ocean floor behind (to the left in the drawing).

As explained above, according to the method for laying an elongated body on the seabed according to the present invention, the first to nth sheaves are placed on the first to nth elongated body coils in which the elongated body is in a continuous state. Since the elongated body of each coil is passed through these sheaves in a special condition, the elongated body of each coil is passed through these sheaves in a special condition. When the cable is moved, the change can be made on patrol without stopping the laying vessel.

Therefore, according to the present invention, it is possible to efficiently install a long body without any danger.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram showing an implementation state of a conventional installation method, and FIG. 2 is an explanatory diagram showing an example of an implementation state of the installation method of the present invention. 1... Long body, 2 □, 22... First,
Second elongated body coil, 3... Laying ship, 4...
... Frame, 51°5□ ... First and second sheaves, 3A, curved, long body feeding end.

Claims (1)

[Claims] 1. The first to nth (n is an integer of 2 or more) elongated body coils are mounted on the laying vessel, the smallest numbered one of which is located on the side closer to the elongated body feeding end of the said laying vessel, and the number are arranged and mounted in the longitudinal direction of the laying vessel such that the largest one is located on the far side from the end of the elongated body,
First to n-th sheaves are placed in correspondence above the first to n-th elongated body coils, and the long length of the elongated body coil having a larger number among the adjacent elongated body coils. The distal end of the body faces the sheave above it, rises from the side far from the first sheave, passes over it, descends from the side close to the first sheave, and moves to the next smaller numbered sheave. The distal end side of the elongate body of the first elongate body coil is connected to the distal end side of the elongate body coil, and the distal end side of the elongate body of the first elongate body coil is close to the second sheave toward the first sheave above it. The hook is passed so that it rises from the side and passes over it to the end of the elongated body being fed out from the said laying vessel, and in this state, the elongated body is sequentially and continuously drawn from said first elongated body coil. A method for laying a long body on the seabed, which is characterized by sending it out into the sea.