Galloping control in bundle conductor transmission lines

Abstract From the Canadian patent

In an overhead transmission line comprising a bundle of conductors, each span of the line defining a torsionally oscillatory system, the mass distribution of the system with respect to the central torsional axis is asymmetrical. In this way the torsional stiffness of the bundle is modified so as to raise the natural frequency of oscillation in the torsional mode substantially above the natural frequency of oscillation in the transverse mode, thereby to prevent coupling between the modes and so prevent build-up of galloping vibrations.