Waves in the periodic overhead-conductor systems of electrified railways

The interaction between overhead conductor and pantograph is analysed by the use of the theory of waves in periodic systems composed of discrete elements. The equations of motion are linearised, and each of the identical spans is represented by only two masses. A 2-fold infinity of critical speeds is to be expected for a continuous cable, although only a few critical speeds are significant in practice. The speeds depend entirely on the measurable characteristics of the overhead-conductor system.