1. To reduce passing railway noise, the Land Transport Authority (LTA) will install noise barriers at three more sites at Tampines, Jurong East and Toh Guan, following the successful installation of barriers at Jurong East and Bishan.
2. The barriers at the two locations had successfully reduced passing railway noise by at least 5 decibels (dBA), measured from the façade of the nearest residential block.
3. As part of the Jurong East Modification Project (JEMP), LTA had installed the noise barriers along parts of the new viaduct at Jurong East, close to some HDB blocks, within 15m at certain stretches.
4. LTA has also completed the installation of 180m of noise barriers along the open tracks next to the Bishan MRT station, where the configuration of the MRT tracks and structures includes a tunnel portal near a block of flats.
Award of Tender for More Noise Barriers
5. Following the earlier installations, additional barriers will be installed at Tampines, Jurong East and Toh Guan. These installations will also act as pilot projects to help study how noise barriers can be set up at different types of tracks and also further test noise mitigation effectiveness. LTA has awarded the tender for the additional noise barrier installation to CKT Thomas Pte Ltd at a cost of about $5 million. CKT Thomas was also the contractor for the noise barrier trial at Bishan.
Noise Barriers on Elevated Viaducts
6. The noise barriers to be installed at Tampines Street 21 (next to Block 269) and Jurong East Street 13 (next to Block 110) will be similar to those installed at Bishan.
7. These two locations were selected as the eastern and western stretches of the viaduct come with different designs. The two projects will allow LTA to test the installation methodology of noise barriers at different segments of the existing viaducts, and assess the most efficient design and installation method that can subsequently be applied to other locations.
8. LTA expects to take about one year to complete the installation works. Upon completion, the noise barriers are expected to reduce noise levels from passing trains by at least 5dBA.
Noise Barrier at Turnout Location
9. LTA will also install a 150m long, 4.5m high noise barrier at the turnout location at Toh Guan Road (next to Blk 266).
10. Turnout locations are areas where two separate tracks merge for trains to be diverted from one track to another. As noise levels are higher when trains cross the tracks at the turnouts, and it is also not possible to install noise barriers adjacent to the tracks where the trains change tracks, the noise barrier will be higher here to effectively mitigate the noise.
11. The installation work for the implementation of noise barrier at the turnout location will entail greater complexity and will take about one and a half years to complete. The barriers at the turnout location are expected to be able to reduce noise levels from passing trains by up to 10dBA.
12. The installation of noise barriers is a complex procedure. Work can only be done during the narrow window when train services are not operating which is from 0130hrs to 0430hrs. The installation also has to contend with the maintenance requirements by SMRT on the operating network and the on-going resignalling and sleeper replacement projects.
Island-wide Railway Noise Study Completed
13. LTA has also completed the islandwide noise measurement study as part of the plan to address railway noise. The study began in September 2011, and covered the entire length of all elevated MRT tracks island-wide, including 455 blocks of flats located close to elevated viaducts or turnouts. The study has identified a number of locations along the elevated tracks that experience high railway noise levels and will need special attention. LTA will use this information to look into the appropriate noise mitigation measures and announce the implementation plan in early 2013. The implementation plan will focus on stretches of track that are close to residential units.
14. With an ageing MRT system that has been in operation since 1987 and increased train frequencies to better serve commuters, LTA recognises that some residents living particularly close to the MRT viaducts may experience increased noise levels. LTA will continue to work with SMRT to tighten the maintenance regime of the train fleet and tracks to minimise noise.
Annex A: Noise Barrier Types and Design
Annex B: Photographs of Noise Barrier Trials