ABSTRACT
Icing of railway contact wires in the cold climates of the USA, Canada, China, Japan, and South Korea can cause significant problems and delays in the operation schedules of electric-powered trains and subway cars. As anti-icing methods, manual de-icing, contact-wire thermal running, resistive-wire-heating de-icing, and chemical de-icing have all been explored and tested. Among them, environmentally friendly chemical de-icing based on the same concept as that of automobileengine antifreezer can be practically effective for application to contact wires at railcar depots. In the present study, the railway contact wires are coated with anti-icing mixtures of ethylene glycol/tap water and glycerol/tap water at various ratios (v/v %) as well as with tap water alone, at temperatures of -30 and -40 °C in a deep freezer. The morphological change on the wire surfaces is observed under optical microscopy. The surface-contact angles are measured to examine the surface difference between uncoated and coated railway contact-wire fragments. Conclusively, the fragments coated with 40/60 and 60/40 (v/v %) ratios of ethylene glycol or glycerol with tap water, as compared with the uncoated fragments, are shown to have been effectively de-iced. The surface-characterizations data thus indicate that mixtures of glycerol or ethylene glycol with tap water can be practical de-icing agents for application to railway contact wires.
