JPH0126484B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a device for investigating the landing state of cables laid on the bottom of water.

Generally, when a cable is laid on the ocean floor, etc., and the location is made of uneven hard rock, etc.
A cable may be laid across two or more convex portions, for example, in a hole-like portion, in a so-called overbridge configuration. In this case, there is a danger that the contact portion between the cable and the rock will slide over a long period of time due to the influence of tidal currents and the like, ultimately resulting in an accident such as a breakage of the cable. For this reason, after the cable is laid, it is necessary to inspect whether it has completely landed on the seabed, and if there is overbridge, it must be removed.

Conventionally, inspections in this case have been carried out by means such as visual inspection by a diver or by taking pictures with a television camera, but in conditions such as deep depths or poor visibility, such inspections have become difficult. was completely impossible.

The present invention was made in view of the above situation, and it is possible to inspect the landing state of a cable laid on the underwater floor easily, easily, and reliably indirectly, rather than by direct means such as visual inspection by a diver or camera photography. The purpose is to provide an investigation device.

The landing state investigation device for a cable laid on the water bottom of the present invention is loosely inserted into a cable laid on the water bottom, and has an elliptical cross section so that the axial direction of the cable and the long axis of the ellipse are perpendicular to each other. A rotary investigation member formed such that the long axis is located in a vertical direction when attached and cannot touch the bottom surface such as a recess position at the bottom of the water, and the rotary investigation member can be moved along the cable. The rotary survey member is provided with a traction wire rope attached to the rotary survey member, and a landing position detection device that detects the landing position of the rotary survey member at each position in which the long axis of the ellipse of the rotary survey member is in a vertical direction and a horizontal direction. Means is provided with a transmission device attached thereto for transmitting a signal of the bottom attitude of the rotating investigation member from the landing attitude detection device to a boat on the water.

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the apparatus for investigating the landing state of cables laid on the bottom of water according to the present invention will be described below with reference to FIGS. 1 and 2. FIG. 1 is an explanatory diagram of the landing state inspection situation, and FIG. 2 is a sectional view taken along the - arrow in FIG. 1. In the figure, 1 is a cable laid on the seabed, 2 is a rotating survey member, which is loosely inserted into the cable 1 and has an elliptical cross section so that the axial direction of the cable 1 and the long axis of the ellipse are perpendicular to each other. It is formed so that the long axis of the ellipse is located in the vertical direction when it is attached and cannot come into contact with the seabed surface 5, such as in a recessed position on the bottom of the water. Reference numeral 3 denotes a non-rotating member, which is connected to the rotating investigating member 2 and has a pulling wire rope 4 attached thereto for dragging the rotating investigating member 2. Reference numeral 8 denotes a landing posture detection device, and an arc-shaped sealed hollow portion 9 is formed internally at the longitudinal end of the rotation investigation member 2 with the central axis of the ellipse on the center side of the radius, and a plurality of devices are formed within the arc-shaped sealed hollow portion 9. It consists of a contact 6 and a liquid conductive member made of mercury 7 filled inside so as to occupy a part of the space. The landing attitude detection device 8 electrically changes the connection of the contact 6 between on and off depending on the position of the mercury 7 in the landing attitude detection device 8, and transmits the information obtained thereby to a ship on the water (ocean). Then, the posture of the rotating survey member 2 on the water bottom can be determined by using a known transmission device (not shown), such as drawing out an electric signal through a wire or emitting a sound wave with a different wavelength from each contact point 6 and detecting it on board. It forms a means for detecting.

The rotary investigation member 2 is formed so that when it is located at the recess position 10 portion of the seabed surface 5 (see FIG. 3), the landing attitude detection device 8 side is always located at the lower end side. For this reason, the hole 11 into which the cable 1 is loosely inserted is provided eccentrically, not at the center of the elliptical cross section, and when floating in water, the same position is always the lowest position. In addition, by providing a cavity on one of the major axis sides of the elliptical cross section, attaching a weight, or composing a composite material with a different specific gravity, it is formed so that when it floats in water, the same direction is always the bottom side. Good too. The rotation investigation member 2 may be formed in two pieces.

The cable 1 is inserted into the hole 11 of the rotating investigation member 2 and laid on the seabed surface 5. Then, at the same time as the laying or after the laying, the rotating investigation member 2 is connected to the cable 1 via the traction wire rope 4.
along the seabed surface 5 in the direction of arrow A. If the cable 1 is in the concave position 10, for example, as shown in FIG. 3, and the long axis of the ellipse is not in parallel contact with the seabed surface 5, that is, in a state where it is floating in the water and has not landed, the landing detection device 8 detects its position. The situation is detected, a signal thereof is transmitted to a ship on the sea, and the landing attitude of the rotating investigation member 2 is indirectly detected.

Since the device for investigating the landing state of cables laid on the water bottom of this embodiment is configured in this way, there is no need for divers to dive underwater for visual confirmation or to take pictures on television, making it easy and simple. Moreover, the landing state can be detected reliably.

As described above, the device for investigating the landing state of cables laid on the underwater bottom according to the present invention has the effect of easily and reliably inspecting it indirectly, rather than by direct means such as visual inspection by divers or camera photography. It is something.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram of the landing inspection state of an embodiment of the landing state investigation device for a cable laid on the underwater bottom according to the present invention. FIG. 2 is a cross-sectional view taken along the - arrow in FIG. FIG. 4 is a cross-sectional view of the rotating investigation member shown in FIG. 1 from which the landing attitude detection device is attached. 1...Wire rope, 2...Rotating investigation member, 4
... Traction wire rope, 5 ... Seabed surface, 6 ... Contact, 7 ... Mercury, 8 ... Landing attitude detection device, 10
...Recess position.

Claims (1)

[Claims] 1 It is loosely inserted into the cable laid on the bottom of the water,
It has an elliptical cross section and is installed so that the cable axis direction and the long axis of the ellipse are perpendicular to each other, so that the long axis is located in the vertical direction when the cable cannot contact the bottom surface of a recessed position on the bottom of the water. a rotating investigation member formed in the above-mentioned cable; a traction wire rope attached so as to be able to move the rotating investigation member along the cable; A landing attitude detection device for detecting the landing attitude at each position is provided on the rotating investigation member, and a transmission device is attached for transmitting a signal of the underwater attitude of the rotating investigation member from the landing attitude detection device to the watercraft. 1. An apparatus for investigating the landing state of a cable laid on the bottom of water, characterized by comprising: