The re-signalling project for the North South Line (NSL) and Tuas West Extension (TWE) will take between four and six months to stabilise amid upgrading works and “teething issues”, train operator SMRT and the Land Transport Authority (LTA) said on Friday (14 July).
At a press conference held jointly by LTA and SMRT to announce a new software upgrade to the signalling system, SMRT told the media that the train operator could not rule out more train faults occurring during the software upgrade, which will begin on Friday night and continue over the weekend.
The software update is expected to address several teething issues, such as to improve alignment between train and platform screen doors, trackside to train communications, and strengthen the signalling system’s main server.
SMRT and LTA also said that testing of the new signalling system during commuter hours, which began in late May, was inevitable, in part because other maintenance works had to be carried out during engineering hours.
SMRT Trains CEO Lee Ling Wee, who spoke on behalf of SMRT, said that delays relating to the new system have reduced over the past weeks.
He pointed out that not all the delays caused on the North-South and East-West Lines (NSEWL) over the recent weeks were due to the new system.
“From time to time, we still encounter signalling faults due to the ageing legacy signalling system that is still running part of the East-West Line (EWL) from Pasir Ris to Pioneer station,” said Lee.
Lee pointed out that the incident on Wednesday morning (12 July), which caused delays on the East-West Line for more than two hours, was due to a track circuit failure, and nothing to do with the new system.
Ngien Hoon Ping, LTA’s Chief Executive, said at the conference that other countries could stop train services over weekends for testing but Singapore could not afford to do the same.
SMRT has been plagued by a recent spate of train faults and delays in the past few weeks, with at least four incidents this month and another string of delays in June.
On Wednesday night, a traction power trip disrupted train services on the NSEWL, causing blackouts on trains. On Monday, services along the EWL were delayed due to a signalling fault.
The delay to trains pulling the NSEWL during evening rush hour on 28 June was related to the new system. However, it was a “one-off” incident caused by human error and not a flaw in the software itself, SMRT said. A team from signalling systems supplier Thales had not implemented the software incorrectly, causing all trains on the NSL and TWE to lose communications and come to a halt.
LTA and SMRT also elaborated on the implementation of the new signalling system and the challenges that have arisen since it was deployed.
One of these challenges includes trains switching over to the new system from the legacy system when they switch lines at Jurong East Station, since the EWL is currently operating on the old system.
Even though the actual switch takes one and a half minutes, this adds to delays in commuters’ journeys.
While trains on the NSL and TWE can fall back on the legacy system should the new system fail, the delays may take up to 30 minutes as the process involves stations and control centres.
SMRT plans to extend testing of the new system on the EWL in stages in the coming months, and will apply the testing to commuter hours in December this year, if all goes according to plan.
On behalf of SMRT, Lee said, “I apologise for the inconveniences to commuters over the past weeks.
“The completion of the NSEWL re-signalling project will bring long-term benefits to our commuters. These include more reliable train services and an increase in train capacity, translating into shorter waiting time and less platform congestion during peak hours.”