Rolling Noise Control at Source – Mitigation Measures for Existing and New Rail Transit Systems
adcIn 1997, TCRP Report 23: Wheel/Rail Noise Control Manual was published. The purpose of this Manual was to identify mitigation measures for wheel/rail noise produced by rail transit systems, and to provide practical procedures for noise control. In the years since this Manual was written, there has been considerable international research activity into wheel/rail noise. In particular, advancements have been made in the understanding of options to reduce wheel/rail rolling noise at source.
Wheel/rail rolling noise remains a common issue for new and existing rail transit systems. It is well known in principal that mitigating noise at-source is usually more cost-effective than mitigation measures targeting the propagation path or the receiver. However, in practice many transit operators, project proponents and acoustic consultants have a poor understanding of what at-source noise control actually means and how to achieve it. For rail transit rolling noise, source control measures include:
• minimizing wheel and rail roughness or corrugation, including by specialized acoustic grinding / milling or by use of friction modifiers on existing systems
• optimizing the design of wheels and selection of track components to minimize noise for new systems
• adding damping to wheels or rails to minimize radiated noise for new or existing systems
It can be difficult to quantify the potential noise benefit of a particular source noise control measure even for existing rail transit systems. The benefit achieved on one system may be quite different to that achieved on a different system, with a different baseline. For new or planned rail transit systems it is even more difficult as there is often no definitive information on long term system maintenance challenges and how maintenance practices will affect noise emissions. The benefit of source noise control could be up to 20 dB in some cases, but much less in others. Quantifying the benefits of source noise control requires an understanding of railway maintenance practices in addition to acoustic theory. In contrast, it is straightforward for an acoustician to calculate the noise reduction provided by a noise barrier. As a result, noise barriers are commonly assumed to be the only feasible solution to rail transit rolling noise issues and the potential benefits of source control are not quantified or realized in many cases.
Noise barriers can provide highly effective noise mitigation in some situations, but they are expensive, add additional weight and wind loading to guideway structures, and have adverse visual impacts. They are also ineffective in urban areas with high-rise residential buildings overlooking the tracks, as in this situation a barrier will not break the line of sight to the noise source. Increasing the awareness of transit operators, project proponents and acoustic consultants of alternative at-source rail noise mitigation measures is expected to reduce costs for new projects, and to provide more options for existing systems to maintain a state of good repair and minimize operational noise impacts on neighboring communities.
A TCRP synthesis study would consolidate available documented information on source control for rail transit rolling noise. It would update the information provided in TCRP Report 23, documenting source noise control practices that have been used successfully on recent projects worldwide. It would identify ongoing research in this area, and describe methods and tools that are available to resolve uncertainties in quantifying the benefits of the various source noise control options for particular rail transit systems.
The output of the study would be a reference report for transit operators, project proponents and acoustic consultants, and would facilitate the increased consideration and use of cost-effective at-source noise control measures by North American transit systems.
|Sponsoring Committee:||AEP80, Transportation-Related Noise and Vibration
|RNS Developer:||Briony Croft|
|Source Info:||D.J. Thompson, M.H.A. Janssens, and F.G. de Beer (1999) TWINS: Track-Wheel Interaction Noise Software, theoretical manual (version 3.0). TNO report HAG-RPT-990211, Delft.|
D.J. Thompson, C.J.C. Jones (2000) Using theoretical models to design low noise wheels and track. Transportation Research Record, Journal of the TRB, 1702, 1-56.
D.J. Thompson, C.J.C. Jones, T.P. Waters and D. Farrington (2007) A tuned damping device for reducing noise from railway track, Applied Acoustics, 68(1), 43-57.
D. J. Thompson (2009) Railway Noise and Vibration Mechanisms, Modelling and Means of Control. Elsevier, Oxford.
B. Suarez, J.A. Chover, P.Rodriguez and F.J. Gonzalez (2011) Effectiveness of resilient wheels in reducing noise and vibrations. Proceedings of the Institution of Mechanical Engineers, Part F: Journal of Rail and Rapid Transit Vol 225, Issue 6, pp. 545 – 565.
Betgen, B., Bouvet, P., Squicciarini, G. and Thompson, D.J. (2013) The STARDAMP software: an assessment tool for wheel and rail damper efficiency. In AIA-DAGA 2013 Conference on Acoustics, Merano, Italy.
Torstensson, P.T. and Nielsen, J.C.O. (2015) Rail Corrugation Growth on Curves – Measurements, Modelling and Mitigation. In Noise and Vibration Mitigation for Rail Transportation Systems Notes on Numerical Fluid Mechanics and Multidisciplinary Design Volume 126 pp 659-666.
Proceedings of the International Workshop on Railway Noise (2004, 2007, 2010, 2013, 2016, 2019)
|Index Terms:||Rolling contact, Noise, Noise control, Rail transit, |