Abstract
Telephone cable shielding must provide electrical and mechanical shielding for the entire life of the cable. Thus, mechanical and electrical properties are important in the shielding design. In order that these properties are properly maintained, the shielding materials must also be corrosion resistant.
The impact of corrosion on buried telephone cable shielding materials has been demonstrated over the last thirty years in a wide range of laboratory and soil burial tests sponsored by the Rural Electrification Administration (REA) and conducted by the National Bureau of Standards (NBS) and Industrial Organizations.
This paper discusses the importance of corrosion resistance in cable shielding materials, describes the mechanisms of shielding corrosion which occur in buried telephone cable, and evaluates the results of the six years REA Horry Coop buried telephone cable corrosion test. In this study, both active and static cables were included. Withdrawals were made over a six year period. These cables were evaluated for cable shielding corrosion. Special attention was paid to the comparative behavior of active and static cables.
Results indicate that steel shieldings are most susceptible to the effects of AC in active cables. Results of a wide range of shieldings are presented and evaluated.
