Sound Dampening Methods for HDB Blocks Near MRT Tracks

Mr Alex Yam asked the Minister for Transport with regard to noise from MRT tracks (a) how many HDB blocks are currently within 15 metres of such tracks; (b) what are the methods of sound dampening that are currently used; and (c) whether new methods of sound dampening are being explored.

Mr Lui Tuck Yew: In determining the track alignment for the elevated MRT lines, LTA takes into consideration the distance between the tracks and the nearby residential buildings. However, as our MRT lines pass through high-density corridors, it is inevitable that some of the elevated tracks will be located quite close to the residential buildings. Generally, there is a minimum setback of 25-35 metres for residential buildings located near the MRT tracks, depending on the specific site constraints and the orientation of buildings.

Currently, there is only one HDB residential block at Jurong East Street 21 which is located within 15 metres of the MRT track. The close proximity was due to the need to build a new track as part of the Jurong East Modification Project (JEMP) in order to relieve the infrastructural bottleneck of the North-South and East-West Lines. In view of site constraints, the track had to be built within 15 metres of the existing HDB block. As part of the JEMP, LTA also installed noise barriers at this location to mitigate the noise from passing trains. The noise barriers have helped to reduce noise to around the same levels as before the implementation of the JEMP.

Besides the noise barriers installed at the MRT viaducts along Jurong East Street 21, LTA is also piloting the implementation of noise barriers along the open tracks next to the Bishan MRT station. The implementation is targeted to be completed by July 2012. Two additional locations – Tampines Street 21 and Jurong East Street 13 – have also been identified for further trials to test the effectiveness of noise barriers on different track configurations. LTA is also piloting the implementation of a noise barrier at the turnout location along Toh Guan Road. The trials will allow LTA to determine the most appropriate and cost-effective method to mitigate railway noise levels, before customising the implementation at other locations.

As part of the holistic plan to address railway noise, LTA has also embarked on an island-wide noise measurement study along the entire length of all elevated MRT tracks island-wide. The study is expected to be completed by April 2012, and will enable LTA to identify locations that require special attention.

With the findings from the trials and noise measurement study, LTA will develop and share the preliminary plan for railway noise mitigation around the 3rd Quarter of 2012.

In the meantime, LTA will continue to work with SMRT to ensure that they maintain the tracks and grind the wheels of their trains regularly to reduce railway noise. Where necessary, LTA will work with SMRT to tighten the maintenance regime. LTA is also looking into installing permanent noise sensors to measure the noise levels of passing trains, so that the areas where additional maintenance work is needed can be identified expeditiously.

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