Engineers are to trial an innovative way to reduce airborne noise from rail tracks, which requires minimal intervention.
A Transport for London (TfL) trial between Woodford and South Woodford stations will use a spray-on product called Quietrail, where a thin membrane is sprayed onto the web of the rail (the indented section) to produce noise reduction of around seven decibels.
After receiving noise complaints from Woodford residents engineers inspected the tracks but found nothing wrong.
“The track formation was in a good condition, there was no corrugation of the track, the fixtures and fittings were complete and there was no apparent cause,” said TfL London Underground head of operational upgrades and asset development Duncan Weir.
He concluded it was just noise from the trains on the Central Line running over the track.
“Clearly it was causing disturbance to the people, that’s why they’d complained, and that’s why I asked my engineering team to source or innovate a solution,” he said.
Weir’s team went out to the marketplace and found Quietrail, a self-adhesive membrane around 4.5mm thick which dampens noise from vibrations by transforming energy from the rail vibration into heat instead of noise. It is non-toxic and does not affect ballast realignment.
Although widely used in the automotive and marine industries, this is the first time it has been used on rail tracks. Noise readings will be taken to assess the impact of Quietrail.
If the results from the trial, starting in May and lasting six months to a year, are positive the technology could be rolled out to other locations across the network.
“We believe there are other sites where we might be able to use that as an engineering solution if it does give us the reduction in noise we are expecting,” said Weir.
Quietrail is believed to reduce railway noise by around seven decibels. Noise at the Woodford site is around 50 decibels, because of the proximity of surrounding properties to the tracks.
Details of the trial were revealed yesterday (Thursday 16 March) as Weir was questioned by the London Assembly Environment Committee over the impacts of noise from the Tube.