JPS5924610B2 - How to land a long body on the seabed - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for landing a long submarine body (for example, a submarine cable, a water pipe, a pipe, etc.), and in particular, the method of unloading a long submarine body (for example, a submarine cable, water pipe, pipe, etc.) This invention relates to a method for changing the position of the elongated object from the stern to the bow when the elongated object is unloaded by the sea floating method after mooring the laying ship.

BACKGROUND OF THE INVENTION As shown in FIG. Long body 10
When unloading, the following is generally done:

■) All the elongated bodies 10 remaining in the laying vessel 16 are brought out onto the sea surface 14 and floated with buoys 38 attached (Fig. 1).
, 2) The final end of the elongated body 10 is pulled up onto the land 42 (FIG. 2), and 3) The buoy 38 is removed and the elongated body 10 is sunk.

This method requires a wide area of water because the entire remaining elongate body 10 is to be floated on the sea.

Furthermore, there is a risk that the elongated body 10 will be damaged.

In order to minimize the risk, the situation (sea winds and waves, currents, etc.)
Depending on the topography, for example, whether the elongated body is located in a deep sea area, it may be convenient to change the position of the elongated body 10 toward the land 42.

In such a case, conventionally, the laying vessel 16 to be moored was
The ship was rotated by 10° to point the stern 160 toward land 42.

However, this work is ■) very difficult, 2) there is a risk of creating loops or kinks in the long bodies, and 3) especially when multiple long bodies are laid at the same time, the long bodies may intersect. There are disadvantages such as making it impossible to implement the system.

OBJECT OF THE INVENTION It is an object of the invention to provide a method that eliminates the above-mentioned drawbacks and allows the position of feeding out the elongated body to be changed from the stern to the bow without changing the mooring direction of the laying ship.

In the embodiment "Figures 3 and 4", 10 is a long seabed body, 12 is a seabed, and 14 is a sea surface.

16 is the laying ship, 160 is its stern, 162 is the bow, 18
2 is a long body tank, 20 is a tower, and 22 is a foil provided on top of the tower.

A feeding facility 29 including a roller 24, a drawing machine 26, and a sheave 28 is provided from the foil 22 toward the stern 160.

The above is the same as the conventional case.

In the present invention, the equipment on the laying ship 16 is further configured as follows (.

1) For example, a rotating table 30 is provided on the tower 20, and it is made to be able to rotate at least 90 degrees (preferably greater than 90 degrees, and approximately 180 degrees is appropriate) around a vertical axis 320 passing through the center of the tower 20. .

A foil 22 is then mounted thereon to allow for a change of direction from the stern 160 to the bow 162.

2) Another set of unwinding equipment 129 from the foil 22 toward the bow 162, namely the roller 124 and the unwinding machine 126
, sheave 128, etc. are provided.

Although the present invention can be easily carried out even when two strips of the elongated body 10 and one OA are laid at the same time as shown in "Fig. 4", in order to avoid complexity, the method shown in "Fig. 3"and"
The illustration of the other set is omitted below in "Fig. 5", and the following explanation will be given only for one set.

(Li) The construction ship 16 is moored with the bow 162 facing the land 42.

34 is an anchor. The elongated body 10 is fixed to a stopper 36 (buoy at a fixed position) to prevent movement and deformation of the elongated body 10 (FIGS. 3 and 4).

Then, the elongated body 10 is let out from the stern 160, and the buoy 38
Float on the sea surface 14 while attaching.

At that time, the small boat 40 is pulled to prevent the elongated body 10 from deforming.

At this time, the feeding length is such that the long body 10 is
The length required for transferring the cable from the cable to the unwinding equipment 129 on the bow 162 side, specifically about 1.5 to 2 times the total length of the laying vessel 16.

Therefore, especially when the long body is fed out over a long distance (for example, 5
00m or more), the effect is significant.

(2) After the elongated body 10 is paid out by the above-mentioned length, the elongated body 10 is removed from the feeding equipment 29.

Also, the foil 22 is turned 1801 and directed toward the bow 162.

Meanwhile, the long body 10 on the sea is moved from the stern 160 side to the bow 162 side (FIG. 5).

(3) After moving the elongated body 10 to the bow 162 side, remove a part of the buoy 38, and attach the elongated body 10 to the roller 124, the drawer 126, and the sheave 128 in this order.
．． Figure 6).

When the attachment of the elongated body 10 to the feeding equipment 129 is completed (FIG. 6), the elongated body 10 is removed from the anchor 34.

(4) Reversely rotate the drawer 126 to remove the long body 10 on the sea.
is temporarily stored in the long body tank 18.

Then, the elongated body 10 is laid in a straight line on the seabed 12 (
Figure 7).

That is, the elongated body 10 is laid on the seabed 12 below the laying ship 16 and appears above the sea surface 14 on the bow 162 side.

(5) Fixing the elongated body 10 to the stopper 136.

Then, the drawer 126 is rotated in the normal direction to float the entire elongated body 10 on the sea surface 14 (FIG. 8).

After that, the procedure is the same as in the case of the conventional floating method.

(6) Note that the operation in (4) above can also be omitted.

Therefore, this work step is excluded from the scope of the claims.

Effects of the Invention (1) Reliability can be achieved in landing operations that may cause loops or kinks in the elongated body 10.

(2) It can also be applied when two or more elongated bodies 10 are laid simultaneously.

(3) Long-distance landing (when the distance is long, such as in shallow waters)
suitable for

[Brief explanation of the drawing]

Figures 1 and 2 are general explanatory diagrams of the sea floating method, and Figures 3, 5, 6, 7, and 8 are explanations showing embodiments of the present invention in the order of steps. 4 corresponds to the plan view of FIG. 3 and shows the case where two strips are laid at the same time. 10... Long body, 16... Laying ship, 1
60... Stern, 162... Bow, 18
... Long body tank, 22 ... Foil,
24...Kolo, 26...Drawer machine, 2
8... Sheave, 29... Feeding equipment,
124... Roller, 126... Drawer, 128... Sheave, 129... Feeding equipment.

Claims (1)

[Claims] 1. A foil 22 is provided above the elongated tank 18, and from the foil 22 toward the stern 160, a roller 24, a drawer 2
6. Laying ship 1 equipped with unwinding equipment 29 including sheave 28
6, while sailing towards land 42, the long body 10 is paid out from the stern 160 and laid, and after being moored near the shore, the long body 10 remaining inside the ship is paid out and placed on the sea surface. 14, and then the final end of the elongated body 10 is pulled onto land. In this method, the foil 22 is made so that it can be turned from the stern 160 to the bow 162. Further, on the laying ship 16, a pay-out equipment 129 including a roller 124, a puller 126, and a sheep 128 is installed from the foil 22 toward the bow 162 (and pays out all the remaining elongated bodies 10 as described above). Before taking out the elongated body 10, the elongated body 10 is paid out from the stern 160 by an appropriate length and placed on the sea surface 14.
After floating on top, the elongated body 10 is removed from the feeding equipment 29 and the foil 22 is removed.
is directed toward the bow 162 at a constant angle, the elongated body 10 is attached to the feeding equipment 129, and the feeding position of the elongated body 10 is changed to the side of the bow 162. How to land a long body on the seabed.