JPH0341765B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an apparatus for investigating the landing state of a cable laid on the underwater bottom.

For example, when laying a cable on the ocean floor, if the ocean floor is made of uneven hard rock,
A cable may be laid in a so-called overbridge configuration in which the cable is laid across a concave position with two or more convex portions. In this case, the contact portion between the cable and the rock will slide over a long period of time due to the influence of the tidal current, ultimately leading to the risk of an accident such as a breakage of the cable. For this reason, after the cable is laid, it is necessary to detect whether it has completely touched the bottom of the seabed, and if there is an overbridge condition, it is necessary to remove it.

Traditionally, this inspection has been carried out by direct means, such as visual observation by a diver or taking pictures with a television camera, but in conditions such as deep water or poor visibility, these operations are completely impossible. It was impossible.

The present invention was developed to address the above situation, and does not involve direct means such as visual inspection by divers or camera photography, but indirect methods that allow cables to be easily and reliably fixed even in situations where visibility is poor. The object of the present invention is to provide an apparatus for investigating the landing state of a cable laid on the underwater bottom, which can detect the landing state of a cable laid on the underwater bottom. That is, the landing state investigation device for a cable laid on the underwater bottom of the present invention includes a movable investigation member that is loosely inserted into the cable laid on the underwater bottom and rotatably attached to the outer periphery of the cable;
A traction wire rope is connected to the movable investigation member so as to be rotatable relative to the outer periphery of the cable, and the movable investigation member is formed so as to be able to be towed along the cable from above the water. , arranged at four or more locations at predetermined intervals along the outer periphery of the substantially central ampulla of the movable investigation member, each consisting of a pin, a spring, and a contact, so that when the movable investigation member lands, The present invention is characterized in that it is provided with a detection member that detects the applied pressure irrespective of its rotational position, and means configured to transmit the pressure detected by the detection member to a watercraft by an electrical signal. DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of an apparatus for investigating the landing state of a cable installed on the bottom of water according to the present invention will be described below with reference to FIGS. 1 and 2. Figure 1 is an explanatory diagram of the landing situation investigation status on the seabed surface, and Figure 2 is the
FIG. 6 is an explanatory diagram of the operation of the detection member of the moving investigation member shown in the figure. In each figure, 1 is a cable, and 2 is a movable investigation member, which is formed in the shape of an elliptical sphere or an oblong sphere, and has a hole 9 larger than the outer diameter of the cable 1 in the center in the longitudinal direction, and the cable 1 is loosely inserted through the hole 9. . A large number of detection members 8 are disposed on the outer periphery of the movable investigation member 2 in the minor axis direction at predetermined pitches for detecting pressure applied to the movable investigation member 2. Each of the detection members 8 consists of a pin 3, a spring 6, and a contact 7 as shown in FIG. 2, and as shown in FIG. When the pressure on the member 2 is only water pressure, the pin 3 is projected outward by the tension of the spring 6, and the distance between it and the contact 7 is opened. Further, when the movable investigation member 2 is on the bottom of the seabed and pressure from the seafloor 5 is applied to the movable investigation member 2, the springs 6 of at least one or more detection members 8 are activated as shown in FIG. As shown in (b), the pin 3 is compressed in the direction of the arrow and comes into contact with the contact point 7.
The open/close state of the pin 3 and the contact 7 is indirectly detected by a means comprising a transmission device (not shown) that transmits an electrical signal to a ship on the water. Incidentally, the above-mentioned transmission device is constituted by a well-known electric circuit including a pressure/electricity conversion member. As described above, the apparatus of this embodiment detects special pressure applied to the movable investigation member 2 by opening and closing the pin 3 and the contact 7 to investigate the bottoming situation. In addition, the movable investigation member 2 of this embodiment has a detection member 8 arranged around the entire circumference, so that bottoming can be detected at a freely rotated position when a rotational force is applied by a tidal current while moving. . In order to be able to detect pressure when landing on the bottom regardless of the rotational position of the movable investigation member 2, it is necessary to provide the detection members 8 at four or more locations at a predetermined pitch.

4 is a traction wire rope, and the moving investigation member 2
The movable investigation member 2 is rotatably connected to the outer periphery of the cable 1 via a coupling device (not shown), and the movable investigation member 2 can be towed along the cable 1 from above the water. It's becoming like that.
After laying the cable 1 on the seabed surface 5, the movable investigation member 2 is attached to the cable 1 via the traction wire rope 1.
By moving the cable 1 in the longitudinal direction, the installation status of the cable 1 on the seabed surface 5 can be investigated. That is, when pressurization is not detected as shown in Fig. 2A, it is possible to indirectly detect from the water that the mobile survey unit 2 has not touched the bottom of the seabed 5, that is, is in an overbridge state. Can be detected reliably.

As explained in the above embodiments, the landing state investigation device for cables laid on the underwater bottom of the present invention does not use direct means such as visual inspection by divers or the influence of cameras, but indirectly under conditions where visibility is poor. This has the effect that the landing state of the cable can be easily and reliably detected even in the case of

[Brief explanation of drawings]

Fig. 1 is an explanatory diagram of the landing situation investigation state on the seabed surface of the first embodiment of the landing state investigation device for a cable laid on the underwater bottom according to the present invention, and Fig. 2 A and B are respectively for the mobile investigation of Fig. 1. FIG. 6 is an explanatory diagram of the operation of the detection member of the member. 1: Cable, 2: Moving investigation member, 3: Pin,
4: Traction wire rope, 5: Seabed surface, 6: Spring,
7: Contact, 8: Detection member, 9: Cable insertion hole.

Claims (1)

[Claims] 1. A movable investigation member 2 that is loosely inserted into a cable 1 laid on the bottom of the water and rotatably attached to the outer periphery of the cable 1; A pulling wire rope 4 is connected in a rotatable manner and is formed so that the movable investigation member 2 can be towed from above the water along the cable 1; They are arranged at four or more locations along the outer periphery at predetermined intervals, each consisting of a pin 3, a spring 6, and a contact point 7, and the pressure received when the movable investigation member 2 lands is determined by its rotational position. A cable laid on the bottom of the water, characterized in that it is provided with a detection member 8 that detects the pressure regardless of the pressure, and a means configured to transmit the pressure detected by the detection member 8 to a ship on the water by an electrical signal. Landing condition investigation device.