JPH0452567B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] This inventive communication cable, more specifically,
The present invention relates to an underwater seismic cable having at least one tension member disposed upstream within the shaped cross section.

[Prior art and problems]

In offshore seismic observation, communication cables are essential for towing the gun array and for supplying power, air, and electricity for shooting operations. Conventionally, cables of this type have been used, such as cables in which bundles are coated with various air hoses, tension cables, conductive wires, etc., and armored cables that include the hoses, etc. The connecting cable may be deformed due to the load applied when winding the cable, etc.
There was a problem in that it lacked durability because it caused damage to the conductive wire and caused electrical leakage. That is, when the bundle is wound around a sheave or drum, the tension cable causes friction on the conductor wire, and more specifically, the tension cable applies point pressure on the conductor wire, causing damage to the conductor wire. Another drawback was that it caused electrical leakage. One way to overcome these drawbacks is to use a wire rope tension cable like a kind of clothesline, and connect the wire rope tension cable and a covered circular bundle of electrical cables and air hoses with rope or the like. A method was used in which multiple points were connected to obtain high tensile strength of the wire rope tension cable, but the high stress did not extend to the adjacent bundle of electrical cables and air hoses. This method is useful as long as the bundle can be pulled up like an accordion without hoisting it up, but as the distance between the tug and the towed object increases and the cable length increases, The resistance received from
This method also had the disadvantage that it was impractical and its effectiveness was diminished because it required lifting work rather than drum winding.

Furthermore, this method has the disadvantage that local bending tends to occur in the bundle, and as this bending is repeated, the life of the bundle is shortened. As an alternative to this method, a method was considered in which the tension wire, air hose, and conductive wire were integrated into one connecting cable, but when the conductive wire and hose were bent into a circular shape around the pulley, the conductive wire and hose The disadvantage was that the cable was crushed, causing electrical and gas leakage, and shortening the cable's lifespan. A method has also been devised that uses an armored cable in which a hose and conductive wire are inserted into the outer shell tension member. Although this method was satisfactory from the viewpoint of cable strength and windability, it was difficult to use because the connecting cable was heavy, it was difficult to seal the cable end, and the replacement cost was high. It had problems such as questionable reliability. Furthermore, all of the above methods have the problem of high resistance in seawater due to the large overall diameter of the cable and unsuitable cross-sectional shape. This becomes noticeable when towing the vehicle. Details will be described later. As a commercially available connection cable, there is Flexpack (registered trademark) manufactured by Hydrill, but since Flexpack has tension cables arranged at both ends of the cable, it is not the same as the present invention. In addition, the orthopedic connection cable Flexnose (registered trademark) manufactured by Huasom Oceanology
This cable is made by connecting various members with clips, and is different from the communication cable of the present invention which is integrally molded.

[Means to solve the problem]

This invention was made to solve the above problems, and it is possible to use a pulley to pull up and wind onto a reel without any trouble, and also to have a shaped cross section with a small coefficient of resistance in seawater. The object of the present invention is to provide cables, in particular cables, which are characterized by the fact that the conductor wire is coated with a jacket having a shaped cross section that is continuously extruded, and more particularly, the conductor wire and the air hose are coated with a jacket having a shaped cross section. A connecting cable for towing a towing object in which a tension member having good axial strength is arranged side by side in a jacket having a flat or substantially flat cross section, and the hose is located at a position biased to one side in the longitudinal direction of the cross section of the jacket. The tension member is arranged at a position biased to the other side in the longitudinal direction of the cross section, so that the connecting cable is maintained in a flat position in the water along the wave cutting direction when the connecting cable is towed. . Further, according to the present invention, a covered electrical cable with a relatively small tension, in which a plurality of conductive wires are twisted around a soft flexible core member, and a tension member are arranged side by side in the jacket. Said cable is most suitable for Saismic cable. In particular, a structure is adopted in which the hose is disposed at a position biased to one side in the longitudinal direction of the jacket cross section, and the tension member is disposed at a position biased to the other longitudinal direction of the jacket cross section, so that the center of gravity of the cable is adjusted to the position of the center of gravity of the cable. Since the position can be set to be biased toward the tension member side than the buoyancy center position of the cable, the underwater posture when towing the connecting cable can be set to a flat position along the wave cutting direction with the tension member positioned forward in the wave cutting direction. It is easy to maintain a stable posture, and the drag coefficient in water when being towed can be minimized.

〔Example〕

Next, one embodiment of the present invention will be described in detail.

As shown in FIG. 1, a subarray 10 is towed to a position quite far outside the mother ship or tugboat 12 via an earthquake observation communication cable 11.
Although multiple floats are normally used, only one float is shown in the figure for convenience. For the purpose of seismic research, it is considered desirable to tow a large number of floats on one side of the tug, far outboard. Offset width from the longitudinal axis of the float 13
is directly influenced by the hydrodynamic resistance force experienced by the connecting cable 11. Therefore, in order to solve the problem of increased offset width, a shaped cable is required in which one or more tension members are disposed at the front end of the cross section. Examples of this type of shaped cable are shown in FIGS. 2 and 3, respectively. The illustrated cable is shaped into the shape of an airplane wing to reduce drag. Circular cables generally have a resistance coefficient of about 1.2 to 1.3, although this varies depending on their diameter. On the other hand, flat cables of the same thickness have a resistance coefficient of about 0.13, which is about an order of magnitude different. As shown in Figures 2 and 3,
Tension members 20, 30 are arranged at the forefront of the communication cable in the cutting direction, and behind them are electric cables 21, 31 and air hoses 22, 30.
32 are arranged. Tension members 20, 3
0, it is preferable to use a steel wire rope which has torsion-stable anti-kink properties and does not twist even when the connecting cable is loaded. A bundle of electrical cables 21, 31 is arranged behind the tension members 20, 30, and these bundles are connected to the tension member 2.
It is configured to have greater elasticity in the axial direction as compared to 0.0 and 30. Preferably, a plurality of twisted pair insulated conductive wires are wound in multiple layers to form a cylinder, and soft insertion materials 23, 33 such as soft rubber are inserted into the hollow circle. It is desirable that the material has elasticity such that it contracts or expands in the radial direction depending on the situation. Adjacent conductive wires 21, 31 are arranged so as not to rub tightly against each other. The plurality of twisted pairs of conductors in each layer are also spaced apart from one another, imparting bending properties to the conductors, resulting in an axially flexible cable.
Arranged behind the tension member and the electrical bundle are air hoses 22, 32 which are likewise designed to be axially flexible.

A plurality of bundles (three in FIG. 2, two in FIG. 3) in which a plurality of tension members 20, 30 are stacked in a circular shape are coated with a soft coating material, and the bundles are stacked in a circular shape as shown in FIG. , or fixedly arranged in parallel as shown in FIG.
Similarly, electrical bundles 21, 31 are also coated with a soft coating. The three components, the tension member, the electrical bundle, and the air or fluid hose, are passed through a plastic injection mold and the outer plastic jackets 24, 34 are mold coated. The molding material is preferably nitrile rubber or polyurethane, which has excellent durability and bending resistance.

The two types of connecting cables shown in Figures 2 and 3 exhibit somewhat similar behavior in seawater due to the similarity in the fluid behavior of the fluid passing over the outer circumferential surface. As shown in FIGS. 4 and 5, there are differences in how they are wound and stored. The flat connecting cable shown in Figure 5 is wound in a single ribbon with the flat surfaces overlapping in the radial direction of the drum, whereas the streamlined connecting cable shown in Figure 4 has its tip on the drum surface. oriented, each cable is automatically wound one after the other on the drum without radially overlapping each other. For this reason, the longitudinal width of the hoisting drum in FIG. 4 is set to be sufficiently large.
The communication cables are arranged so that they do not overlap each other. Both the cable's air hose and conductive elements are structurally designed to have a high degree of flexibility against axial stretching and compression, resulting in excessive stress when the cable is wound onto the drum. Not at all. The shaped connection cable shown in FIG. 5 is different from the connection cable shown in FIG.
The stress that is applied during winding is extremely low. This is because the bending axes or pitch axes of the conductive member 31 and the air hose 32 coincide with the bending axis of the tension member 30.

Since the tension members 20, 30 are torque balanced, they will not twist under varying axial loading conditions, which is a very important factor in the flat shaped connecting cable of FIG. Since the connecting cable shown in Figure 4 does not have a flat surface, if the distance between the wound cables increases, the cable may become kinked. Therefore, the cable should be wound on the drum without any gaps, and the structure of the cable should be symmetrical. It is desirable that the axis, ie the longitudinal axis of the cable in FIG. 2, be kept in place. Fifth
An advantage of the cable shown is that it can be wound onto a ribbon reel. In other words, it is not necessary to wind the windings so that they do not overlap as shown in FIG. 4, and it is possible to wind the windings multiple times. Therefore, the cable is wound and stored not in the small diameter and long dimension as shown in FIG. 4, but in the large diameter and short dimension. Furthermore, it has the advantage that tension member stress during winding acts on the reel and is not transmitted to the conductive wire. On the other hand, in the case of a circular cable, due to tension member stress,
The conductive wire is compressed during winding.

The cable shown in FIG. 5 has a structure that prevents such compression, so it can be wound and stored using an outrigger reel. This is because the inclusions in the interconnection cable, such as electrical conductors and air hoses, are essentially laid down on the reel and the entire stress is exerted on the tension member.

The communication cable of the present invention can be used not only as the aforementioned Saismic cable but also as a communication cable for towing objects such as submarines. Furthermore, by changing the direction of the shaped cross section of the connecting cable from horizontal to vertical, or to an intermediate direction, the state of resistance exerted by seawater can be changed, and the connected towed object can be positioned directly behind or directly below the tug. You can also do it.

The communication cable described above is merely one embodiment of the present invention and may be modified without departing from the spirit of the invention and within the scope of the claims of the present invention.

[Brief explanation of drawings]

Figure 1 is a plan view showing the subarray being towed by a tugboat, Figures 2 and 3 are cross-sectional views of the cable, and Figures 4 and 5 are cross-sectional views of the cable wound and stored in a reel or drum. It is. 10...Sub array, 11...Communication cable,
12...Tugboat, 13...Offset width, 20,3
0... Tension member, 21, 31... Electric bundle, 22, 32... Air hose, 23, 33...
...insert material, 24, 34...jacket.

Claims (1)

[Claims] 1. A plurality of conductive wires 21, 31 and hoses 22, 3
2, the conductive wires 21, 31 and hoses 22, 32
The tension member 20 has greater axial strength than the tension member 20,
30 and a jacket 2 having a flat or substantially flat cross section.
4, 34, the hoses 22, 32 are located at a position biased to one side in the longitudinal direction of the jacket cross section, and the tension member 20 is located at a position biased to the other longitudinal direction of the jacket cross section. . 2. The connecting cable according to claim 1, wherein the jackets 24, 34 are integrally molded with a shaped cross section, and the tension members 20, 30 are disposed at the front end of the shaped cross section. 3. The communication cable according to claim 1, wherein the plurality of conductive wires 21, 31 are twisted together on the outer periphery of soft insertion core members 23, 33. 4. A connecting cable according to claim 1, wherein the tension members 20, 30 are wire ropes with anti-kink properties. 5 The plurality of conductive wires 21, 31, the hose 2
2, 32. The connecting cable according to claim 1, wherein torque balance between the tension members 20, 30 and the integrally molded jackets 24, 34 is maintained. 6 Tension members 20, 30, hose 22,
32, and a plurality of tension-removal conductive wires 21 twisted together on the outer periphery of the soft insertion core members 23, 33,
31 and a jacket 2 having a flat or substantially flat cross section.
4, 34, the hoses 22, 32 are located at a position biased to one side in the longitudinal direction of the jacket cross section, and the tension member 20 is located at a position biased to the other longitudinal direction of the jacket cross section. . 7. The connecting cable according to claim 6, which is provided with a ribbon reel for storing the cable winding, and the entire bending stress generated when the cable is wound on the ribbon reel is applied to the tension member 30. 8 The tension member 30 and the plurality of conductive wires 3
8. A connecting cable according to claim 7, wherein the connecting cable 1 is covered with a jacket 34 having a shaped cross section. 9 A connecting cable for towing a towing object consisting of a plurality of conductive wires covered with jackets 24, 34 having a flat or substantially flat cross section and having a uniform shaped cross section, with a hose attached at a position biased to one side in the longitudinal direction of the jacket cross section. 22, 32 are tension members 20, 3 at positions offset to the other side in the longitudinal direction of the jacket cross section.
0 is arranged so that when the connecting cable is towed, its underwater attitude is maintained in a flat attitude along the wave cutting direction. 10. The connecting cable of claim 9, wherein the length to thickness of the connecting cable is in the range of 2/1 to 5/1. 11. The connecting cable according to claim 9, wherein the shaped cross-section front end portion of the connecting cable has greater axial strength than the remaining portion. 12 A plurality of conductive wires 21, 31 and the conductive wire 2
A connecting cable for towing a towing object, in which tension members 20, 30 having an axial strength greater than those of 1, 31 are placed side by side in jackets 24, 34 having a flat or substantially flat cross section, the cable having tension members 20, 30 having axial strength greater than those of The hoses 22 and 32 are located at an offset position.
The tension members 20, 30 are disposed at positions biased to the other side in the longitudinal direction of the jacket cross section, so that the underwater posture when pulling the connecting cable is maintained in a flat posture along the wave cutting direction. There is a contact cable. 13. The connecting cable according to claim 12, wherein the jackets 24, 34 are integrally molded with a shaped cross section, and the tension members 20, 30 are disposed at the front ends of the shaped cross sections. 14. The connecting cable according to claim 12, wherein torque balance between the tension members 20, 30 and the jackets 24, 34 is maintained.