Combating Curve Squeal: Monitoring existing applications

Curve squeal is the intense high frequency tonal noise that can occur when a railway vehicle traverses a curve or a switch. The high noise level causes annoyance for people who live in the neighbourhood of the squealing railway track as well as for the passengers waiting in stations with curves. The Combating Curve Squeal project is sponsored by the International Union of Railways (UIC) in order to develop tools to reduce curve induced squealing. The focus is to obtain applicable solutions. In phase 1, an overview of the extent of the noise problem for railways and a toolbox with methods and solutions to combat squeal noise were produced. In addition, work on a theoretical model was further advanced. As a conclusion, it was found that in principle solutions do exist, but several questions connected to their application have not yet been answered. Phase 2 of the project addresses these questions by concentrating on noise monitoring of existing solutions against squeal noise. Mainly infrastructure-based solutions to combat squeal noise in hot spots such as friction modification and asymmetric grinding will be assessed for further analysis. The aim is to obtain a preliminary design manual for practical solutions for the railways to reduce squeal noise. A measurement protocol and rig tests support these efforts. This paper focuses on the presentation of the applications and the development of the test procedure.