The Downtown Line 3 (DTL3) project will be a step closer to be up and running, when the Land Transport Authority (LTA) hands over the new 21km, 16-station rail line to operator SBS Transit in August.
SBS will then conduct trial runs and staff training to get the DTL3 ready for its opening, targeted to take place by the year end.
In the next four months, LTA will also progressively ramp up tests of the entire Downtown Line (DTL) system, by running trains between the existing DTL network and the new DTL3.
The present network with the DTL1 and DTL2, which opened in 2013 and 2015 respectively, stretches from Bukit Panjang to Chinatown. The DTL3 will run from Fort Canning to Expo, passing through areas such as Jalan Besar, Ubi and Tampines.
To facilitate tests of the entire DTL, LTA said yesterday that train services will start about 11/2 hours later on Sundays, from the middle of next month until August.
The delayed start will give rail engineers more time during off-service hours to test the system, on top of the three hours of engineering time they have each night.
It is necessary because it takes 2hr 20mins for a train to travel from Bukit Panjang to Expo, the DTL3's last stop, and make the return journey, said LTA director for rail systems Yee Boon Cheow.
More trains will also be used for the tests, with extra time needed to prepare, launch and withdraw them, Mr Yee added.
Currently, up to 29 trains are used on the existing DTL network during peak hours. The number is expected to double when DTL3 is opened. For the Sunday tests, 35 trains will be used initially, with the number raised progressively.
On average, 220,376 commuters ride the DTL daily and this is expected to hit more than half a million when the DTL is fully opened.
During the tests, LTA will monitor the system performance of the whole line, including checking train movements and announcements as well as the intervals between the arrivals of each train at a station, said Mr Yee.
The Sunday schedule during this test period from May 14 to Aug 27 will see the the first train leaving Bukit Panjang station for Chinatown at 7.31am, instead of 5.50am. The first train in the opposite direction will leave Chinatown station at 7.31am instead of 6.28am.
Trains will run on their normal schedule on June 25, during the Hari Raya Puasa weekend.
On the affected Sundays, a shuttle bus service will run parallel to the existing DTL network and stop at each of the 18 stations.