Railway noise and vibration
ISVR Consulting and the ISVR Dynamics Group have a team of specialists with a unique understanding of noise and vibration from overground railways, underground railways and tramways.
ISVR Consulting is currently undertaking ground-borne noise and vibration predictions for an extension to an underground railway system. The sites were visited to measure transfer functions for vibration transmitted through the soil from a tunnel to the surface. We then used prediction methods developed in-house by Dr Chris Jones of the ISVR Dynamics Group to predict vibration levels at the ground surface in the vicinity of the route and to evaluate the benefits of using different types of track.
ISVR Consulting has an impressive portfolio of other high-profile projects including:
- Thessaloniki Underground Complex, Greece: ISVR Consulting undertook the ground-borne noise and vibration predictions for a state-of-the-art underground line in Greece's second largest city. The track will run in twin tunnels at a maximum depth of 28 metres. The route follows a main road through the city and will pass a number of sensitive and historic buildings including a university, a hospital, prestigious hotels and a concert hall.
- Croydon Tramlink: Ground-borne vibration from similar vehicles in Sheffield was measured and transposed to the Croydon site, based on ground propagation measurements at Croydon. The rolling noise with different track systems was predicted by mathematical modelling and the benefits of vibration mitigation assessed.
- Heathrow Terminal 5 Underground Complex: ISVR Consulting was engaged to predict the likely levels of ground-borne noise from underground trains that could occur in the new terminal building, and its satellites. Recommendations were made to reduce the potential impacts to acceptable levels.
- Jubilee Line Extension, London
- Crossrail, London
- Lantau Crossing, Hong Kong
- London Underground, Effects on ground vibration of a tunnel strengthening scheme
Internal noise and vibration
ISVR Consulting also has much experience of measuring and assessing noise within trains, and has been working with Greenstreet Berman on two projects for the Rail Safety and Standards Board (RSSB).
The first project was the design of a set of ergonomic alarm and alert sounds for the GSM-R cab radio system for communications between drivers, signallers and others. The sounds were designed to be easily and quickly identified, to be readily heard above the noise in the driver's cab, to convey an appropriate degree of urgency, and to not conflict with or interfere with sounds from existing equipment already fitted in cabs, such as the ‘Automatic Warning System’ (AWS) and the ‘Driver Safety Device’ (DSD). The GSM-R system has been trialled in Scotland.
The second project concerned sound levels from warning devices in train cabs, such as the AWS and DSD. We prepared a practical guidance document which will allow train operators or manufacturers to set sound levels of current and future warning devices in each type of cab, so that the sounds will be heard reliably, but will not be so loud as to cause annoyance or even discomfort. We have recorded and analysed the ambient noise in driver’s cabs of electric passenger trains and a diesel-electric freight locomotive to test the procedures, and these measurements will be included as example case studies within the guidance.