JPH01231215A - Optical fiber complex underwater cable - Google Patents

Abstract

PURPOSE:To reduce electrical corrosion by using a material of an equal ionization tendency value for an outer sheath wire and a metal pipe. CONSTITUTION:An outer sheath wire 2 such as an iron wire is used for all around a cable core 1 comprising an electric power cable core, a tele-communications cable core or the complex construction thereof, thereby forming a corrosion prevention layer 3. Furthermore, one or a plurality of the outer sheath wires 2 formed into a metal pipe 5 containing an optical fiber 4 is formed with a metal tape of the same material as the outer sheath wire 2. The outer sheath wire 2 and the metal pipe 5 are made of the same material or such a material as having the same ionization tendency value. According to the aforesaid construction, it is possible to prevent the early electrical corrosion of the outer sheath wire 2.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Technology] The present invention relates to improvements in optical composite submarine cables.

[Prior art]

Conventionally, various optical composite submarine cables have been proposed, such as the one disclosed in Japanese Utility Model Application Publication No. 56-32314. As shown in No. 11m, in this type of cable, for example, an electrical cable core, a communication cable core, or a cable core l made of a composite of these cables is sheathed with an armor wire 2 such as iron wire, and this is provided with anti-corrosion protection as necessary. A layer 3 is applied thereto, and one or more of the sheath wires 20 are made into a metal tube 5 made of, for example, stainless steel and containing an optical fiber 4.

A feature of this type of optical composite submarine cable is that the outer diameter of the metal tube 5 containing the optical fiber is made to match the outer diameter of the adjacent iron wire armored wire 2 or to be smaller than this. causing the armored wire 2 to receive pressure from
The point is that it has been devised so that no direct pressure is applied to it.

However, when this type of cable is used for a long period of time, a problem has arisen in that the armored wire 2 side corrodes at a rate that would be unimaginable due to conventional corrosion caused by seawater alone.

(Object of the Invention) In view of the above-mentioned problem, the object of the present invention is to slow down the progress of corrosion of the armor wire in an optical composite submarine cable, or the optical fiber-containing metal tube assembled together with the armor wire.

[Structure of the invention]

In order to achieve the above-mentioned object [1], the present invention provides a l-band cable having a cable core and several tn armored wires sheathed on the outside of the cable core, wherein one or more of the sheathed wires are The optical composite submarine cable is a metal tube containing an optical fiber, and the armored wire and the metal tube are made of materials having the same ionization tendency.

[Embodiments of the invention] Embodiments of the present invention will be described in detail below with reference to the drawings.

As a result of repeated various experiments, the present inventor found that the cause of the early corrosion of the armored wire 2 described above is that there was a difference in ionization tendency between the metal tube 5 containing the optical fiber 4 and this armored wire 2. I came to believe that this was due to electrical corrosion occurring. When the metal tube 5 was formed from a metal tape made of the same material as the iron wire sheathing wire 2 shown in FIG. 1, it was found that early corrosion of the sheathing wire 2 could be prevented.

In this experiment, the sheathing wire 2 and the metal tube 5 were made of iron, but basically they should be made of the same material, or the aluminum should have the same ionization tendency value. Which one to select may be selected depending on the ease of manufacturing the metal tube 5, etc.

Further, the metal tube 5 containing the optical fiber 4 may be filled with, for example, a sherry mixture for waterproofing or a water-absorbing swelling powder for waterproofing purposes.

〔Effect of the invention〕

As described above, according to the present invention, an optical composite submarine cable with little electrical corrosion can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view showing an example of an optical composite submarine cable according to the present invention. 1~Cable core 2~Exterior wire 4~Optical fiber 5~
Metal pipe patent applicant Furukawa Electric Co., Ltd.

Claims (1)

[Claims] An optical composite submarine cable having a cable core and a plurality of armored wires sheathed on the outside of the cable core, wherein one or more of the armored wires is a metal tube containing an optical fiber. An optical composite submarine cable characterized in that the wire and the metal tube are made of materials whose ionization tendency values are the same.