File:Bell telephone magazine (1922) (14755833622).jpg

Identifier: belltelephonevol3132mag00amerrich (find matches)
Title: Bell telephone magazine
Year: 1922 (1920s)
Authors: American Telephone and Telegraph Company American Telephone and Telegraph Company. Information Dept
Subjects: Telephone
Publisher: (New York, American Telephone and Telegraph Co., etc.)
Contributing Library: Prelinger Library
Digitizing Sponsor: Internet Archive

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ke sure thatbuilders, road workers,or other constructionpeople will not unknow-ingly damage the plant.In some of the more ac-tive areas, this ride isa daily affair, and inothers it may occur oncea week. In the wider spacesof the West, where our cables goacross country rather than along thehighways, such patrols may be madefrom an airplane. For example, theburied cable between Shreveport, Dal-las, and El Paso is one which is regu-larly patrolled by air to guard againstunwitting damage by farmers or bypipeline, oil well, and similar con-struction workers. hine Insulation Testing Although inspections are effectiveand economical in keeping the out-side plant in good condition, theycannot be completed often enough toprevent the development of serioustroubles between the cycles. Thelargest source of such trouble is wa-ter or moisture getting inside thesheath of the cables and affecting theinsulation between wires. Duringdry weather, breaks in the cablesheath have little or no effect on cus-
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This outdated manual zvay oj pcrjoriniii^ a line visula- tion test is being superseded by the automatic method shown on the opposite page tomer service, but during a rain-storm, water entering the cable maycause hundrecis of troubles. Thevalue of a means of rapidly detect-ing sheath breaks during dry weatherwas recognized many years ago, butlittle progress was made until theforties—when a new electronic lineinsulation test set and related tech-niques for its use were developed. The success of line insulation test-ing as a preventive maintenancemeasure is attested to by its contri-bution to a 25 percent reduction inthe number of customer reports oftrouble caused by outside plant In1952 as compared to 1947. Thissuccess is not due solely to the devel-opment of new equipment, but shouldbe largely credited to the fine spiritwhich exists on the telephone team.Line insulation testing Is most effec-tively performed in the hours justbefore sunrise. At this time, air In 212 Bell Telephone Mag

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