File:Bell telephone magazine (1922) (14733038336).jpg

Identifier: bellvol25telephonemag00amerrich (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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water level until itreached the cable. Gas pressurewould have kept the water out of thecable and given warning of the break,so that it could have been repairedbefore the cutover was made. On another occasion a cable in aduct underneath a bridge failed whena flood submerged the duct. When the water receded, a large hole wasfound in the cable sheath, evidentlycaused by lightning. As the cluct wasnormally dry, it is not improbablethat the cable had lain in this condi-tion for months. These are typical examples of whatused to happen before the days ofgas pressure. Holes and crackswould develop in cable sheaths, butin the dry season no one would havewarning of them. When the rainsdescended and the floods came, everytestroom in the storm area would bein an uproar. In contrast to this, gaspressure tips off neighboring test-rooms soon after a break of any kind 10 0 GAS PRESSURE TESTING - GRAPH OF PRESSURE READINGS PoleorM.H. No.Pressure Reading SO GS 70 7S 80 as- 4.00 2.4S .60 /.S9 3.32 4.40
Text Appearing After Image:
36 38 40 Valve Locations • Feet x 1000 48 Cable _-^^5^4 -_e£m. jiGas Section Nd._^ Testboard Report No._?r^_ Plotted Location_^4L^M.^-Z/.. Actual Location.i^lf^Z/ ogje Time Error in Feet-<f-fl of Test^^/_AM Made By_/l/<y._. Checked By. Cause of V^^YA^JlSM.^^/f, ^t^Mx CLOC/px Temp._<?^t5_ _ A pressure graph., showiiig how readings at valves on either side of a low-pressure pointmay be charted to locate the point of cable sheath damage 1946 Damaged Telephone Cables Send Their Own Alarms 169 occurs in a sheath, permitting repairs,before service is affected. Developing Gas Methods An early use of gas for the purposeof testing the tightness of solderwork in a telephone cable was initi-ated about 1912 by the Bell Tele-phone Company of Pennsylvania. Inthis use, plant forces gave a cablewhat was called the flash test: dryair was forced into a section of thecable and they listened for gas leaksand checked gauge readings at eitherend of the c

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