Special features in the design of transmission tower lines as imposed by electrical conditions

This paper is confined to the factors which affect the structural and mechanical phases of transmission line design. These are divided into two groups as follows: 1. Factors affecting design of tower. 2. Features involving location of towers. The writer has in general refrained from commenting on the various items listed. Exceptions are made, however, in certain features which in his opinion deserve particular emphasis. Briefly, these are: 1. The consideration of an “economical stringing stress” as described under “Factors affecting Strength of Tower.” 2. The description of transpositions. 3. Features involving location of towers. Views and diagrams are used to describe the transpositions and a table giving data on the standard towers for the 110-kv. and 220-kv. transmission lines of the Pacific Gas and Electric Company is also included.