Constructing Power Lines

Power lines are constructed by stringing the conductors from support to support in a continuous manner and then adjusting the tension in the wire in each span (gap between poles or towers) consecutively. This tension is maintained by tying the conductor to the supports via insulators. The desired tension in the wire suspended between any two supports is a function of the average span length, the size and composition of the wire as well as the anticipated load variations (ice, wind) and temperature extremes encountered in that area. During construction this tension is the same for each span, so initially the supports do no more than provide vertical lift.