Surge characteristics of a buried bare wire

BURIED bare wires are frequently used as grounds or counterpoises for transmission-line towers and also as shield wires for underground rubber-covered telephone wires. Experience has verified the effectiveness of such wires in reducing insulator flashovers for direct strokes to transmission towers and breakdowns of underground rubber-covered wires due to surges. Quantitative relations between surge characteristics of the wires and various fundamental constants are, however, incomplete. Theoretical considerations of surge characteristics appear to have been confined to empirical approximations of test results^1,2,3 and do not reveal the relation to fundamental constants, such as the earth resistivity and dielectric constant of the earth.