Tests of Pocket Gophers Gnawing Electric Cables

Abstract

Rodents of various kinds occasionally gnaw insulation from wires and cause short circuits. Such damage usually occurs on wires located inside buildings or on cables buried underground, although at times tree squirrels become destructive to wires suspended between poles. Pocket gophers (Thomomys, Geomys, and Cratogeomys) are probably the principal offenders responsible for damage to buried cables. In certain localities pocket gophers have been reported gnawing through conduits and insulation on signal cables along railroads. Cases have been reported where the copper conductors as well as the cable insulation were gnawed away by gophers. Because of these instances, this study was undertaken at the request of W. J. Delehanty of the General Electric Company, to test the ability of pocket gophers (Thomomys bottae) to penetrate different types of insulation. Most of the samples used were provided by the General Electric Company, although some (many of which are not illustrated in this article) were furnished by the following: Pacific Telephone and Telegraph Company, Alarm Corporation, Carbon Products Corporation, and Yardley Plastics Com-