Low Friction Metallic Coatings for Reducing Railroad Squeal

Squeal or screech continues to be a major noise pollution problem for rail systems in heavily populated areas. Squeal is a result of stick-slip phenomena in tight curves and switches at relatively low speeds, where the wheels "crab" through the turn. Current solutions for the problem have focused on lubricating the rails with a number of liquid systems including water and greases. However, commercially available systems have only shown mixed success, not only in terms of reducing squeal itself, but also from an economic and environmental standpoint.