Noise & vibration

Noise & vibration

Reducing airborne and groundborne noise and vibrations

Current international standards and regulations contain an increased focus on the levels of noise and vibration emitted by rail services. 

The increasing number of rail services around residential areas whether commuter services, high-speed intercity or freight services has provoked strong debate about the impact of noise levels on the quality of life of those living in close proximity to the tracks, as well as on the structural integrity of surrounding properties.

As a result, there is now an expectation that operators, infrastructure managers and vehicle manufacturers are taking steps to reduce the amount of airborne or groundborne noise and vibrations transmitted by today's rail traffic.

How we can help

Our experts can help measure and verify compliance with regulated noise levels or targets for anything from a sub-component to an entire rail system, and specify the appropriate mitigation requirements to improve on existing performance.

Services

  • Use of in-house software that provides accurate on-site measurements of current noise levels (e.g., soil transmission properties) and calculated modelling of predicted noise levels under any number of variables
  • Advice on low-noise design specifications for new rolling stock, defining recommended controls for noise suppression based on predicted internal and external noise
  • Troubleshooting sudden incidents of excessive noise, providing full diagnosis and definition of mitigation measures
  • Civil engineering design advice, such as anti-vibration bridges, tunnels and stations
  • Specific measurements of wheel and rail roughness and track decay rates, checking their compliance with standards (e.g. ISO3095:2005) or Technical Specifications of Interoperability (TSI)
  • Measurements of sound quality criteria, such as loudness or RASTI figures, in relation to passenger privacy or the intelligibility performance of the PA system in a rail vehicle or station
  • Technical Specifications for Interoperability (TSI) assessments

What are the benefits?

Our up-to-date knowledge of standards and regulations (TSI, ISO standards, codes for environmental impact) will ensure that products or entire systems comply with noise and vibration requirements, regardless of circumstance.
Our clients are supported by a highly specialized team of rail acoustic engineers working with the aid of in-house tools tailored to the rail environment.

Recent projects

  • We carried out a groundborne noise and vibration impact study of a suburban line in Bilbao, Spain. A new line into a cut-and-cover tunnel, which replaced an existing line at grade, prompted a need to predict the impact inside dwellings. Predictions were performed with our software, ODS-Gronav, and completed using experimental data from on-site measurements (i.e. track and soil mobilities and ground velocity levels). Industrial mitigation measures were recommended where necessary
  • At the request of RFF (Réseau Ferré de France), we incorporated a noise-emission monitoring module on the Gotcha wheel-rail measurement platform. The basis for this module is a noise-monitoring terminal designed for permanent monitoring of environmental noise. The information from the terminal is transferred to the Gotcha trackside equipment for further processing and integration with train passage information and then sent to a central server. The information is subsequently distributed to users within RFF and SNCF (French Railways) through a web-based user interface
  • As part of the Whispering Train Programme, we are investigating the impact of various brake blocks on wheel roundness as a means of reducing noise emissions