Lightning Shielding of Plastic Telephone Cable

Data are presented on the surge characteristics of various types and combinations of metals when applied as a shield for buried telephone cables. Surge currents were applied to the shield of 500-foot lengths of cable and the potentials developed between the shield and conductors were measured at selected points along the cable length in order to determine relative susceptibility to lightning influence. The shield metals included copper, aluminum, stainless steel, and low-carbon steel, and combinations of these metals. This program was begun and completed in the calendar year 1968. This program may have a substantial impact in the future designs of cable used in the Rural Electrification Administration systems.