SINGAPORE - Around 14 per cent of the ageing timber sleepers on the East-West Line (EWL) have been replaced with concrete ones, and the project is steaming ahead to finish by the end of 2016.

Rail operator SMRT said that having a larger fleet of Road Rail Vehicles (RRV), which are used to transport and hoist the sleepers onto the tracks, and the setting up of temporary staging areas have helped to maximise the three-hour window it has every night to do the works.

The media was shown a staging area in Kallang during the early hours of Friday morning, where four RRVs are deployed and concrete sleepers are stored.

Sleepers are used to hold tracks in place, and concrete ones are more durable with a longer lifespan of up to 50 years.

Built over a field, the staging area in Kallang is located where the train tracks are fairly level to the ground, allowing the RRV to be launched quickly onto the tracks.

There are similar staging sites in Redhill and near the train depots in Changi and Ulu Pandan.

SMRT said that stopping train services on stretches of the EWL half-an-hour earlier will also allow its contractor, Gammon Construction, to replace 25 per cent more sleepers.

The early closure starts from Nov 15 till the end of the year, with nine stations between Bugis and Tanah Merah being the first stretch to be affected. It will apply from Sunday to Thursday, with the exception of the eve of public holidays.

Mr Roger Lim, SMRT's programme director for track infrastructure, said: "We understand that this will create inconvenience to the public, and we appreciate all the support... so we can expedite the work."

As the works are done early in the morning, Mr Lim said SMRT is taking steps to minimise disturbance to nearby residences.

"We have sound barriers and protection gauze for sound-emitting devices, like generators. We also put noise measuring systems to help us understand the noise generation, so we can stop and control the noise, as and when it reaches a threshold," he added.

There are more than 92,000 timber sleepers to be replaced on the East-West Line.

An earlier project to swap out 96,000 wooden sleepers on the North-South Line was completed in April 2015. Since it started on the re-sleepering efforts two years ago, SMRT has increased its fleet of RRVs from two to 14.