Commuters will have smoother and faster rides on the entire East-West Line (EWL) by year end, when a 1½-year-long project to upgrade rail sleepers is finally completed.
Worn timber sleepers - some as old as 28 years - which had meant a rougher ride for commuters are being replaced by concrete ones.
Temporary speed restrictions - to allow the new sleepers to settle on the ballast bed when freshly installed - will also be fully removed.
Currently, 75 per cent of the upgrading programme is completed, train operator SMRT told The Straits Times.
The entire project will be finished by the end of the year. This is after the deadline was pushed back to early next year following a massive breakdown in July last year.
SMRT has been replacing timber sleepers on the line with longer- lasting concrete ones since May last year. The work has caused speed restrictions to be placed on the line for four- to six-week periods to allow the sleepers time to settle on the ballast bed.
SMRT said that since February, it has been closing stretches of the EWL earlier to allow more work to be done during off-service hours in a bid to make up for lost time. Since June, selected stations have also opened later on Sundays.
Gantry cranes have been used near the Pasir Ris and Chinese Garden MRT stations to allow the faster deployment of engineering vehicles and materials by hoisting them directly onto the tracks.
Previously, the vehicles could be deployed only from depots close to the ground level at Ulu Pandan and Bishan, or from temporary work sites near Kallang and Redhill.
When the project is done, trains will run at normal speeds of up to 80kmh instead of between 40kmh and 60kmh, which has been the case on certain stretches of the line.
Sleepers help to hold the rails in place and there are more than 92,000 on the EWL. The remaining 25 per cent to be replaced are mainly in the western part of the line. Worn sleepers can result in bumpier rides and, in extreme cases, pose a safety risk. Concrete sleepers have a lifespan of 50 years, more than twice that of the timber ones.
"Commuters can look forward to smoother and more comfortable rides," an SMRT spokesman said.
Some 96,000 sleepers on the North-South Line (NSL) were replaced in a separate project which was completed in April last year.
Meanwhile, SMRT said it is also replacing the power-supplying third-rail. The project is 36 per cent complete on the NSL and 42 per cent on the EWL.
A re-signalling project - which will allow trains to run at shorter intervals of 100 seconds instead of 120 seconds now - is also under way. It is 98 per cent complete on the NSL and 76 per cent on the EWL.
Commuter Margaret Tan, 56, a housewife, said: "The trains have been travelling more slowly. A trip from Lakeside to Raffles Place station takes about 10 minutes more.
"But I think during the peak hour, speeds are slower because there are more trains on the line and they have to maintain a safe distance apart."