Effects of ice loading on transmission lines

Wires hung from suspension insulators do not maintain their relative positions as closely as when pin type insulators are used, owing to the deflection of the insulators with unequally loaded spans. During the winter season a transmission line of the Washington Water Power Company was rendered almost useless due to short circuits caused by the stretching and sagging of the wires when unequally loaded with ice, which falls from some spans sooner than others. A series of tests upon an experimental line was made to determine (1) the influence of the loaded line upon the elasticity of the cable; (2) the effect of swing of insulators; (3) the effect of using strain insulators at short intervals, and (4) the combined effect of these conditions. The manner of making the tests is described and the results are shown graphically.