Forty-five-year old Vasan, who has been searching to buy a property in Chennai, is cautious and avoids buying one close to the Metro Rail alignment fearing that his children would be disturbed even by faint rumblings. “It may not be too loud but if you are living adjacent to the tracks, then, it could be a bit annoying to be woken up by the noise every day,” he adds.
To dampen the noise and vibrations, Chennai Metro Rail Ltd. (CMRL) plans to fix high-resilience rail fasteners on the tracks in the Phase II project.
This ₹61,843-crore project will comprise 76 km of elevated tracks and 43 km of underground tracks.
CMRL officials said a study was carried out to check in which areas there was a high possibility of increased vibrations and noise levels that could affect the nearby residents. “In this system, the ballastless track structures are supported by rubber pads which cut down the noise and vibration levels. These will be placed at many locations, including Kolathur, Purasaiwalkam, Perambur, Ayanavaram, Pattalam, Thirumayilai, Kutcheri Road and Mandaiveli,” an official said. Apart from this, rail grinding machines would be used every three months to smoothen the rails to reduce the noise generated while the train is running. Indian Railways has provided guidelines which state that most persons don’t feel a significant impact until the vibration levels crosses 70 VdB (vibration decibels).
The detailed project report indicates that the maximum permissible levels of vibration is 65 vdb but during the study it has been found that structures about 2 metres from the alignment face 73 vdB but with installation of noise barriers it comes down.
Sources said though this was done in Phase I and Phase I extension not many important locations were covered as a result of which rail screeching and vibrations were pronounced.