Evaluation of Resistance at Supporting Pulley of Messenger Wire and Its Influence on Current Collection Characteristics

Tension in overhead contact line systems needs to be constant to maintain acceptable levels of current collection. However, it is conceivable that the tension is not exactly constant, because of the resistance at the supporting pulley of messenger wire. In this study, we investigated the mechanism of such resistance, carried out measurement of tension fluctuation, and examined the movement of messenger wires as part the investigation. Furthermore, in order to investigate the influence of the resistance at the supporting pulley on the current collection, we carried out a simulation to ascertain how current collection characteristics are influenced by changes in messenger wire tension.