JPH0787659B2 - Optical fiber composite aerial ground wire erection method - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method for constructing an optical fiber composite overhead ground wire.

[Prior art and its problems]

In recent years, by constructing an optical fiber composite overhead ground wire on an overhead power transmission line, a high-quality, large-capacity optical communication system using the overhead power transmission line has been constructed, providing stable power supply, system automation, and operational efficiency. Have achieved great results.

Conventionally, erection of an optical fiber composite overhead ground wire has been performed by the same method as that of a normal overhead power transmission line. That is,
Pass the messenger wire between the steel towers to be installed, connect the optical fiber composite overhead ground wire to the end, pull the tip side of the messenger wire with a take-off machine, and brake the sending machine at the sending side of the optical fiber composite overhead ground wire. Is applied, and the optical fiber composite overhead ground wire is extended by applying an appropriate tension.

However, the optical fiber composite overhead ground wire is often extremely long because of the demand to minimize the number of optical fiber connection points in the entire optical communication line. As a result, the wire extension distance becomes long and the number of times the safe passes is increased, so that twisting or crushing of the optical fiber composite overhead ground wire is likely to occur during the wire extension, which may cause the optical fiber to break. There was a problem.

[Means for solving problems and their effects]

An object of the present invention is to provide a method for constructing an optical fiber composite overhead ground wire that solves the above-mentioned problems of the prior art.

In order to achieve this object, the present invention hangs an optical fiber composite overhead ground wire under a normal overhead ground wire in which optical fibers are not combined, and the tension of the optical fiber composite overhead ground wire is set to the above normal overhead ground wire. The optical fiber composite overhead ground wire is erected in a state where the tension is kept lower than the tension.

In other words, in the present invention, in addition to the optical fiber composite overhead ground wire, another normal overhead ground wire is installed, and the tension for the installation of the optical fiber composite overhead ground wire is partially borne by the optical fiber composite overhead ground wire. By lowering the tension applied to the composite overhead ground wire, the twisting and crushing that occur when the optical fiber composite overhead ground wire passes through the gold wheel is eliminated, and the breakage of the optical fiber is eliminated. Further, it is very effective to install the optical fiber composite overhead ground wire under a normal overhead ground wire in order to prevent the optical fiber composite overhead ground wire from being directly hit by lightning after the installation.

〔Example〕

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 1 shows an embodiment of the present invention. In the figure, 11 is a steel tower, 12A and 12B are safes hung from the steel tower, 13 is an ordinary overhead ground wire without optical fibers combined, 14 is an optical fiber composite overhead ground wire, and 15 is a messenger wire.

In this method, the ordinary overhead ground wire 13 and the optical fiber composite overhead ground wire 14 are connected to the rear end of the messenger wire 15 at the tip thereof, and both overhead ground wires 13 and 14 are installed at the same time. At this time, while suspending the optical fiber composite overhead ground wire 14 below the normal overhead ground wire 13 via the suspension member 16, the tension of the optical fiber composite overhead ground wire 14 is lower than the tension of the normal overhead ground wire 13 As described above, the optical fiber composite overhead ground wire 14 is installed between the suspension members 16 in a slightly loosened state. The normal overhead ground wire 13 passes through the upper gold wheel 12A, and the optical fiber composite overhead ground wire 14 passes through the lower gold wheel 12B.
Since the optical fiber composite overhead wire 14 has a low tension, there is no risk of damage such as twisting or crushing.

As the ordinary overhead ground wire 13, a plurality of steel wires or aluminum-coated steel wires 21 are twisted as shown in FIG. 4, and the optical fiber composite overhead ground wire 14 is used as shown in FIG. Optical fiber built-in type shown in FIG. 6 or No. 7
The optical fiber winding type shown in the figure is used. In the optical fiber composite overhead ground wire of FIG. 5, the optical fiber 22 is housed in the groove of the grooved spacer 23, and the metal pipe 24 is provided on the outer periphery thereof.
And a steel wire or an aluminum-coated steel wire 21 is twisted on it. The one shown in FIG.
The optical fiber 22 is twisted around the periphery of the optical fiber, a protective coating 26 such as FRP is provided on the outer periphery of the optical fiber to form an optical unit, which is loosely accommodated in the metal pipe 24, and a segment-shaped steel wire or The aluminum-coated steel wire 21A and the round steel wire or the aluminum-coated steel wire 21B are twisted together. Furthermore, Fig. 6 shows the required number of steel wires or aluminum-coated steel wires.
An optical fiber unit 28 having an FRP coating or the like is spirally wound around the outer circumference of an overhead ground wire main body 27 in which 21 are twisted together.

Further, as the suspending member 16, it is preferable to use a spacer or the like that holds both overhead ground wires 13 and 14 and keeps them at appropriate intervals.

FIG. 2 shows a state after the optical fiber composite overhead ground wire is erected by the above erection method. After the installation, the tension of the optical fiber composite overhead ground wire 14 may be lower than the tension of the normal overhead ground wire 13, but may be the same. Both overhead ground wires 13 and 14 are connected by a spacer 17 at least at one or more places in the span,
It is held at a predetermined interval. As the spacer 17, the hanging member 16 used at the time of installation may be used as it is. 18 is an overhead power transmission line installed under the overhead ground lines 13 and 14.

In this way, the optical fiber composite overhead ground wire 14 is
When installed below 13, the optical fiber composite overhead ground wire 14 is prevented from being directly hit by lightning, so that melting and damage of the optical fiber composite overhead ground wire 14 due to lightning can be prevented, and therefore the optical fiber disconnection is also eliminated. The reliability of the optical communication line can be improved.

FIG. 3 shows another embodiment of the present invention. In this method, an ordinary overhead ground wire 13 is installed first, and the optical fiber composite overhead ground wire 14 is suspended therethrough via a roller-type suspension member 19 to perform the installation. When the optical fiber composite overhead ground wire 13 is pulled by the messenger wire 15 and the suspension member 19 travels, the suspension member 19 travels along the normal overhead ground wire 13 and travels together with the optical fiber composite overhead ground wire 14. By providing such suspension members 19 at intervals narrower than the intervals of the steel tower 11, the optical fiber composite overhead ground wire 14 can be installed with a sufficiently low tension, and twisting or crushing when passing through the safe 12 can be prevented. Occurrence can be prevented. Even with such an erection method, the state after erection is the same as that of the above embodiment.

〔The invention's effect〕

As described above, according to the present invention, the optical fiber composite overhead ground wire can be installed with a sufficiently low tension, so that the optical fiber composite overhead ground wire will not be damaged when passing through the gold train, and therefore during installation. It is possible to prevent disconnection of the optical fiber. After installation, the optical fiber composite overhead ground wire will be located below the normal overhead ground wire, so it will not be directly hit by lightning, and it is possible to prevent melting and damage due to lightning strikes of the optical fiber composite overhead ground wire. The reliability of the optical communication line can be improved.

[Brief description of drawings]

FIG. 1 is an explanatory view showing a method of constructing an optical fiber composite overhead ground wire according to an embodiment of the present invention, FIG. 2 is an explanatory diagram showing a state after construction by the same method, and FIG. FIG. 4 is a sectional view showing an example of an ordinary overhead ground wire, and FIGS. 5 to 7 are sectional views showing an optical fiber composite overhead ground wire. 11-steel tower, 12 / 12A / 12B-gold car, 13-normal overhead ground wire,
14 ~ Optical fiber composite overhead wire, 15 ~ Messenger wire, 16 ~ Hanging member, 19 ~ Hanging member.

Claims (3)

[Claims] 1. An optical fiber composite aerial ground wire is hung below an ordinary aerial ground wire not combined with an optical fiber, and the tension of the optical fiber composite aerial ground wire is kept lower than the tension of the normal aerial ground wire. A method for constructing an optical fiber composite overhead ground wire, comprising: erection of an optical fiber composite overhead ground wire in a closed state. 2. The erection method according to claim 1, wherein the optical fiber composite overhead ground wire is installed together with a normal overhead ground wire. 3. The overhead ground wire according to claim 1, wherein a normal overhead ground wire is installed first, and the optical fiber composite overhead ground wire is hung and installed there. Characterized by.