JPH11115890A - Submarine observation device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain observation data with safety by reducing shock caused by wave or swell on a sea water level at the time of grounding device on the ocean floor through a cable. SOLUTION: A plurality of submarine observation units 2 are mounted on a cage-like structure 1. A pedestal foot 9 is attached to the cage-like structure 1. The cage-like structure 1 is hung from a ship by a cable 5. The cage-like structure 1 is connected to the cable 5 by means of a hanging column 3. A stopper 6 prevents rotation of the hanging column 3. The cable 5 is connected to the hanging column 3 by means of a cable hooking part 4. A shaft core 7 is fitted to a bearing 8 arranged on the cage-like structure 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a seafloor observation apparatus, and more particularly, to a seafloor observation apparatus having a structure for preventing shaking during landing work and receiving no excessive impact when landing on the seabed.

[0002]

2. Description of the Related Art In recent years, marine observation devices and the like have been installed on the sea floor,
Oceanographic surveys are being widely conducted.

FIG. 4 is an explanatory diagram showing an operation state of a conventional seafloor observation apparatus.

FIG. 4 (a) is an explanatory view showing a suspended state on the sea surface, FIG. 4 (b) is an explanatory view showing a state immediately before the bottom of the sea bottom, and FIG. It is explanatory drawing which shows a hanging state.

Referring to FIG. 4A, a conventional seafloor observation device is a cage-like structure 10 on which a seafloor observation device 2 is mounted.
After hanging a single cable 5 wound around a cable drum 22 on a laying boat 21 through a crane 23, the cable 5 is installed on the seabed as it is while loosening the cable 5.
Here, the seafloor observation device includes a cage-like structure 10 on which a plurality of seafloor observation devices 2 are mounted, and a coupling mechanism for coupling the cable 5 to the cage-like structure 10. In this case, considering the balance when the cage-shaped structure 10 is suspended,
The cable anchoring point 11 of the seafloor observation device is determined to be on a straight line connecting the center of gravity (M) 17 supporting the structural weight (W) 18 and the fulcrum 13 from which the cable is pulled out from the crane 23.

When the laid ship 21 is shaken by the waves or undulations when it is lifted by the above-described method, the sway of the seafloor observation apparatus is caused by the swing angle ψ1 due to the movement about the cable drawing fulcrum 13 and the cable holding point 11 as a fulcrum. The motion becomes a double precession with a swing angle of ψ2, and the total swing angle is (ψ
1 + ψ2).

In particular, the cable retaining point 11 and the center of gravity (M)
When the distance from the radiator 17 is short, the swing angle ψ2 becomes very large.

Referring to FIG. 4 (b), when the laying boat 21 sways due to waves or swells, the vertical swing width is ΔL,
Assuming that the swing period is ΔT, the cage structure 10 has V = Δ
It will collide with the sea floor at a collision velocity of L / ΔT. The impact force at this time is the sum of the weight of the seafloor observation device and the weight of the cable 5 hanging the seafloor observation device. The sea bottom observation device apparently collides with the sea bottom at the collision speed V due to this sum of weights.

Referring to FIG. 4 (c), immediately after landing on the seafloor observation device, the cable 5 is extended as an extra length and the tension is relaxed, but the extra length of the loosened cable 5 is supported by the cable retaining point 11 as a fulcrum. Follow the trajectory indicated by the broken line to cover the seafloor observation device. Generally, when laying at a water depth of about 3000 m, it is necessary from experience that the extra extension length is about 20 m due to waves, swells, tides, and water depth measurement errors. If the surplus length is small, the installed seafloor observation device will be lifted again by the swell on the sea and will repeatedly collide. After laying out the extra length, the laying boat 21 lays cables in a cable extra length laying direction 24 indicated by an arrow in the figure.

As an example of such a cable laying technique, an "ocean observation sensor" described in Japanese Patent Application Laid-Open No. 4-357416 is known.

In this publication, an underwater observation sensor connected to a floating body on a water surface via a hanging cable is lowered to a predetermined depth and extended so as to be observable, and it is confirmed that the extension is completed. The technology of a marine sensor with a device is described.

[0012]

The above-mentioned conventional seafloor observation device is directly affected by the sway of the ship on the sea surface because it is hung by a cable. There is a disadvantage that there is.

In addition, when landing on the sea floor, it is difficult to control the payout speed of the cable due to the influence of waves and undulations. Therefore, there is a disadvantage that the equipment is damaged by a strong impact force when the cable collides with the sea floor.

Furthermore, since the adjustment of the cable feeding length is uncertain due to the influence of waves and undulations, there is a drawback in that observation data acquisition is hindered by covering an excessively long cable length more than necessary on the observation device. doing.

[0015] An object of the present invention is to reduce the influence of waves and swells on the sea surface when the observation device lands on the sea floor with a cable, and to obtain observation data safely and without damage due to collision with the sea floor. To provide an observation device.

[0016]

A seafloor observation apparatus according to the present invention is a seafloor observation apparatus which is suspended from a ship with a cable and installed on the seafloor, at a position different from the center of gravity of a cage-like structure on which a plurality of observation instruments are loaded. In addition, a connection fulcrum of a movable coupling portion connected to the cable is provided, and the rotational movement of the movable coupling portion is restricted by a stopper.

In a seafloor observation apparatus which is suspended from a ship by a cable and installed on the seabed, a plurality of observation instruments; a cage-like structure on which these observation instruments are loaded; and a bearing attached to the cage-like structure. A movable coupling part having a shaft core fitted to the bearing part and a cable retaining part for the cable, and connecting the cable and the cage-like structure; and a movable coupling part centering on the shaft core. And a stopper for restricting the rotational movement.

[0018] The invention is characterized in that the bearing is mounted at a position different from the center of gravity of the cage-like structure.

Further, the range of the rotational movement of the movable coupling portion is limited to a rotational angle from horizontal to vertical.

[0020]

Next, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is an external view showing an embodiment of the seafloor observation apparatus according to the present invention.

FIG. 1A is a front view of the seafloor observation device, and FIG. 1B is a plan view of the seafloor observation device.

In this embodiment shown in FIG. 1, a plurality of seafloor observation instruments 2, a cage-like structure 1 on which these are mounted, a pedestal foot 9 attached to this structure, and a cage-like structure 1 A cable 5 for suspending from the ship, a suspending column 3 for suspending the cage-like structure 1, a stopper 6 for restricting rotation of the suspending column 3, a cable retaining portion 4 for coupling the cable 5 to the suspending column 3, It comprises a bearing portion 8 provided on the cage-like structure 1 and a shaft core 7 fitted to the bearing portion 8.

In FIG. 1, components corresponding to those shown in FIG. 4 are denoted by the same reference numerals or symbols, and description thereof will be omitted.

Referring to FIG. 1, a plurality of seafloor observation instruments 2
Is mounted on the cage-like structure 1 and the seafloor observation equipment 2
It is suspended by a single cable 5 that also serves as a communication with the sea and installed on the sea floor. The bearing portion 8 is mounted on a frame 25 forming a part of the cage-like structure 1 at a position different from the center of gravity (M) 15 of the structural weight (W) 16 when all the seafloor observation devices 2 are mounted.

The suspension column 3 has a columnar shape attached to the cage-like structure 1 and has a shaft core 7 fitted to the bearing portion 8 on the column side near one end surface, and a cable 5 of cable 5 on the other end surface. It has a structure to which the retaining portion 4 is attached.

The stopper 6 is attached to the cage-like structure 1 and restricts the rotation of the suspension column 3 about the axis 7 to less than 90 degrees from horizontal to vertical.

FIG. 2 is an explanatory diagram showing one example of operation of the seafloor observation apparatus.

FIG. 2A is an explanatory diagram showing a state immediately before the sea bottom is landed, and FIG. 2B is an explanatory diagram showing a state just after the sea bottom is landed.

Referring to FIG. 2, the operation when the seafloor observation device is suspended and landed will be described. The bearing unit 8 is attached to a frame 25 forming a part of the cage-like structure 1 at a position different from the center of gravity (M) 15 formed by the total weight of the cage-like structure 1 including the seafloor observation device. On the other hand, a suspension pillar 3 having a columnar shape and having a shaft core 7 attached to the side surface of one end surface and a cable retaining portion 4 for retaining the cable 5 attached to the other end surface is fitted to the bearing portion 8. Attach so that they match. When the seafloor observation device having such a structure is suspended using one cable 5, the center of gravity (M)
15 and the cable retaining point 11 of the cable retaining section 4
Are aligned with the axis 26 of the cable 5. In other words, the center of gravity (M) 1 is vertically below the axis 26 of the cable 5.
5 moves. In addition, the cage-shaped structure 1 generates a clockwise torque centering on the suspension fulcrum 12 formed by the shaft core 7 and the structural weight (W) 16 of the seafloor observation device on the center of gravity (M) 15.

However, this torque is balanced by the contact between the stopper 6 attached to the cage-like structure 1 and the side surface of the suspension pillar 3. As a result, the stopper 6 and the suspension column 3 are strongly pressed against each other by the force of the torque, and even if the cable 5 moves due to the shaking of the laying ship 21, only this shaking is transmitted to the seafloor observation device as a primary shaking. Therefore, the shaking that results in the double precession as shown in FIG. 4 is sufficiently suppressed.

As shown in FIG. 2A, when the seafloor observation device is suspended by using one cable 5 and lowered to the seafloor, when the seafloor is horizontal, the seafloor observation is performed with respect to the horizon. It descends while maintaining the angle θ ° formed by the device. Therefore, the pedestal foot 9 of the seafloor observation device first lands on the seabed.
Immediately after the pedestal foot 9 lands, the cage-shaped structure 1 rotates counterclockwise by its own weight around the suspension fulcrum 12 of the shaft core 7, and the suspension pillar 3 separates from the stopper 6,
The weight of the sea bottom observation device is added to the other pedestal foot 9. When the cable 5 is further loosened, the cage-like structure 1 moves in the counterclockwise direction by θ °, and as shown in FIG.
Arrives. When these pedestal feet 9 completely land, the structural weight (M) 15 of the seafloor observation device and the weight of the suspended cable 5 are equally applied to the pedestal feet 9. As described above, the impact time at the time of landing is lengthened and the impact force is reduced by passing through two steps from the time when a part of the seafloor observation device comes into contact with the sea bottom until the entire weight is finally landed. .

Next, the operation after the seafloor observation device has landed on the seafloor will be described with reference to FIG. Pedestal foot 9
Is completely separated from the stopper 6 automatically. This is because the seafloor observation device is θ ° with respect to the seafloor
This is because the suspension 6 restricts the suspension column 3 to less than 90 ° even when the suspension column 3 is almost perpendicular to the sea bottom. Therefore, if the cable 5 is further extended from the laying boat 21 after the bottom of the seafloor observation apparatus, the suspension column 3 always falls down with the suspension fulcrum 12 as a fulcrum in the suspension column stable direction 27 shown by the arrow in the figure, and the suspension column 3 is indicated by a broken line. The horizontal position shown. That is, even if the cable 5 is extended as a surplus length, the surplus length of the cable as in the related art rarely covers the seafloor observation device.

FIG. 3 is an explanatory diagram showing an operation state of the seafloor observation apparatus of FIG.

FIG. 3 (a) is an explanatory view showing a suspended state on the sea surface, FIG. 3 (b) is an explanatory view showing a state just before the bottom of the sea bottom, and FIG. 3 (c) is a cable just after the bottom of the sea bottom. It is explanatory drawing which shows a hanging state.

Referring to FIG. 3 (a), the cage-like structure 1 on which the seafloor observation device 2 is mounted has a bearing portion 8, and the suspension pole 3 has a shaft core 7 fitted to the bearing 8 portion. And a cable retaining portion 4 for retaining the cable 5 fed from the laying boat 21.

The mounting position of the bearing 8 mounted inside the cage-like structure 1 is determined by the cage-like structure 1 on which the seafloor observation device 2 is mounted, that is, the center of gravity (M) of the structural weight (W) 16 of the entire seafloor observation device. ) 15.

When the cable 5 is lifted by the crane 23 of the laying ship 21, the cage-shaped structure 1 generates a clockwise torque by the structural weight (W) 16 around the suspension fulcrum 12 of the shaft core 7, The cage-like structure 1 is provided with a stopper 6 for restricting an attempt to rotate clockwise by torque.

When the crane 23 is suspended by the cable 5 extended from the crane 23 of the laying ship 21, the cable pull-out fulcrum 13 and the cable retaining point 14 of the crane 23 and the center of gravity (M) 15 of the cage-like structure 1 are perpendicular to the sea surface. And line up in a straight line. That is, they coincide with the axis of the cable 5.
The seafloor observation apparatus generates a clockwise rotation torque around the suspension fulcrum 12 of the suspension pole 3 and rotates. The rotation angle is limited by the stopper 6 hitting the suspension pole 3. That is, the stopper 6 and the suspension column 3 are pressed against each other by the above-described torque force F.

Actually, when the weight of the seafloor observation device is set to about 2 tons, the torque force F can produce a force of several hundred kg. If this level of force is obtained, the laying boat 21 shakes due to waves, undulations, tides, and the like, and even if the swing angle の of the cable 5 occurs about several tens of degrees around the cable draw-out fulcrum 13, the cable 6 is suspended from the stopper 6. Since the column 3 does not separate, no double precession due to shaking as shown in FIG. 4 occurs.

Referring to FIG. 3 (b), when the seafloor observation device lands on the sea floor, the pedestal feet 9 of the cage-like structure 1 land first. Since the suspension pillar 3 is separated from the stopper 6 from the moment when the pedestal foot 9 has landed, a part of the weight of the cage structure 1 is added to the pedestal foot 9. Then, cable 5
Is further extended, the other pedestal foot 9 is landed.

At the moment when the pedestal foot 9 has completely landed, the pedestal foot 9 is added with the total weight of the seafloor observation device and the cable 5 suspending the seafloor observation device. As a result, since a part of the seafloor observation device comes into contact with the sea bottom and is finally performed in two steps, the impact time is extended and the impact force is reduced.

Referring to FIG. 3 (c), after the seafloor observation device has landed on the sea floor, when the cable 5 is further extended from the laying ship 21, the suspension pole 3 gradually moves away from the stopper 6, and
Cable 5 connected to cable retaining portion 4 of suspension pole 3
The extra length reaches the sea floor via the trajectory shown by the broken line. Eventually, the suspension pillar 3 falls down to the sea bottom with the suspension fulcrum 12 as the center. Further, the laying boat 21 extends the extra length of the cable 5 and then lays the cable in the extra length laying direction 28 shown by the arrow in the figure. Therefore, the cable 5 does not cover the seafloor observation apparatus and does not hinder the observation equipment.

[0044]

As described above, since the seafloor observation apparatus of the present invention has a structure capable of flexibly controlling the cable payout and suppressing double precession, the ship sways on the sea surface. Therefore, there is an effect that work safety can be ensured without being directly affected by the work.

Further, since the cable feeding speed can easily be controlled by the influence of waves and swells when landing on the sea floor, there is an effect that the equipment is not damaged by collision with the sea floor and impact force.

Further, by adopting the present suspension method, the unwound cable does not cover the seafloor observation device more than necessary, so that there is an effect that there is no trouble in obtaining observation data.

[Brief description of the drawings]

FIG. 1 is an external view showing an embodiment of a seafloor observation apparatus according to the present invention.

FIG. 2 is an explanatory diagram showing an operation example of the seafloor observation device.

FIG. 3 is an explanatory diagram showing an operation state of the seafloor observation device of FIG. 1;

FIG. 4 is an explanatory diagram showing an operation state of a conventional seafloor observation device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Cage-like structure 2 Undersea observation equipment 3 Suspension pole 4 Cable retaining part 5 Cable 6 Stopper 7 Axis 8 Bearing part 9 Pedestal 10 Cage-like structure 11 Cable retaining point 12 Hanging fulcrum 13 Cable pulling-out point 14 Cable retaining point 15 Center of gravity (M) 16 Structural weight (W) 17 Center of gravity (M) 18 Structural weight (W) 21 Laying ship 22 Cable drum 23 Crane 24 Extra cable laying direction 25 Frame 26 Axial core wire 27 Suspension column stable direction 28 Extra cable length Laying direction

Claims (4)

[Claims] 1. A seafloor observation apparatus which is suspended from a ship by a cable and installed on the seabed, wherein a movable coupling portion connected to the cable is connected to a position different from a center of gravity of a cage-like structure on which a plurality of observation instruments are loaded. A seafloor observation device, wherein a fulcrum is installed and the rotational movement of the movable joint is limited by a stopper. 2. A seafloor observation device suspended from a ship with a cable and installed on the seabed, comprising: a plurality of observation devices; a cage-like structure on which these observation devices are loaded; and a bearing attached to the cage-like structure. A movable coupling portion having a shaft core fitted to the bearing portion and a cable retaining portion for the cable, and coupling the cable and the cage-like structure; and the movable coupling portion forms the shaft core. A stopper for limiting a rotational movement that rotates about a center; 3. The seafloor observation apparatus according to claim 2, wherein the bearing is mounted at a position different from a center of gravity of the cage-shaped structure. 4. The seafloor observation apparatus according to claim 1, wherein the range of the rotational movement of the movable joint is limited to a rotational angle from horizontal to vertical.