About 14 per cent of the ageing timber sleepers on the East-West Line (EWL) have been replaced with concrete ones and the project is expected to speed up from tomorrow, when sections of the line will close earlier to give engineering crew more time to work.
This will allow the project to be completed by the end of next year.
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, has also helped to maximise the three-hour window it has every night to do the work.
So has the setting up of temporary staging areas. During the early hours of yesterday, the media was shown a staging area in Kallang, where four RRVs are deployed and concrete sleepers are stored.
Sleepers are used to hold tracks in place. Concrete ones are more durable, with a lifespan of up to 50 years - double that of timber ones.
Built on a field, the Kallang staging area is located where the train tracks are near ground level, allowing the RRVs to be launched quickly onto the tracks. There are similar staging sites in Redhill and near the Changi and Ulu Pandan depots.
SMRT said ending train service 30 minutes earlier on stretches of the EWL will allow its contractor to replace 25 per cent more sleepers every night. A single RRV can replace between 35 and 45 sleepers each night, but with an extra half-hour it can do 44 to 56.
The early end of service will last from tomorrow to the end of the year, with nine stations between Bugis and Tanah Merah being the first to be affected.
It will apply from Sundays to Thursdays, with the exception of the eve of public holidays.
SMRT programme director for track infrastructure Roger Lim said that as the work is done early in the morning, SMRT is taking steps to minimise disturbance to residents.
There are more than 92,000 timber sleepers to be replaced on the EWL. An earlier project to swop out 96,000 wooden sleepers on the North-South Line was completed in April. Since SMRT started on the re-sleepering efforts two years ago, it has increased its fleet of RRVs from two to 14.
On Thursday, SMRT president and group chief executive Desmond Kuek said the firm now spends 41 per cent of each fare revenue dollar on maintenance. This may be raised to 50 per cent by the year end and it covers costs to hire maintenance staff, replacement of depreciating assets and upgrading of older trains.