Theory of the non-elastic and elastic catenary as applied to transmission lines

Equations for length of conductor, span, tension and sag are derived on the basis of a flexible elastic conductor. These equations contain functions of Φ, the angle of bending of the curve in which the conductor hangs, and a constant. The constant is eliminated in two ways leading, (a), to the characteristic ratios of the elastic and non-elastic catenaries, (b), to three equations which give the values of tension, length of conductor and sag in terms of each other. Numerical values of the characteristic ratios of the simple catenary are tabulated for angles less than sixty degrees. By means of this table problems based upon the theory of the non-elastic catenary may be solved readily. The characteristic ratios of the elastic catenary are reduced to more simple approximate forms involving the characteristic ratios of the non-elastic catenary. The equations which give the exact values of the ratios of the elastic catenary are too complicated to use. The results of tests on an experimental span approximately two hundred feet long are given in two tables and these values are compared with the theoretical values based on the non-elastic catenary.