The Land Transport Authority (LTA) is preparing for the third phase of railway noise barrier installation works on the North-South and East-West lines (NSEWL).

It called a tender yesterday to supply and install a total of about 5.5km of noise barriers at 16 new locations along elevated railway sections of the MRT lines, the LTA said.

It expects to award the tender next July, and on-site installation works are due to begin in the third quarter of 2020, following design and off-site fabrication works.

Installation of the barriers, which are expected to reduce noise levels from passing trains by about five to 10 decibels, is expected to be completed by around 2023. When the third phase is completed, there will be 27km of railway noise barriers installed across the island.

Installation on the East-West Line will take place near Pasir Ris, Simei, Tanah Merah, Kembangan, Paya Lebar, Queenstown, Clementi and Lakeside stations.

On the North-South Line, works will take place near two locations in Jurong East, two in Woodlands and one each in Bukit Gombak, Admiralty, Sembawang and Yishun.

The LTA said installation of noise barriers will take place after passenger service hours and will require coordination with other ongoing maintenance and renewal works.

The LTA will prioritise works on elevated tracks where noise levels exceed the National Environment Agency's noise limit of 67 decibels on average over an hour.

The first phase of the noise barriers programme has been completed, while the second began in September and is expected to end by 2020.

The LTA said implementing early closures and late openings on the NSEWL since December last year has helped to speed up the installation of noise barriers.

The LTA will also work with train operators and manufacturers to reduce noise by fitting trains with noise-dampening wheels, using ballast and concrete sleepers on tracks for better absorption of noise, and carrying out service works on train wheels and tracks more frequently.