Transport operator SMRT will commence "live" testing of its new signalling system on the East-West Line (EWL) on five Sundays from April 29 to May 27, according to the Land Transport Authority.
During full-day tests, which will happen when train services are operational, the line will connect Gul Circle and Joo Koon stations. This section of the line was disconnected after a train collision at Joo Koon station on Nov 15 last year.
Shuttle bus services between the two stations will not be available during the test dates. By the end of next month, if all goes well, week-long live testing will commence. The system is expected to be fully ready by June.
The new communications-based train control (CBTC) system will allow trains to run closer together, and arrive at intervals of up to 100 seconds during peak hours, instead of 120 seconds currently.
Previously, tests of the new signalling system were done outside operational hours. All 35 EWL stations have had their operating hours on weekends shortened since March 2, so as to provide more time for engineering staff to test the new signalling system. The last shortened hours on the EWL will be on Sunday.
Commenting on the live testing, the Land Transport Authority's (LTA) deputy chief executive Chua Chong Kheng said: "Trials conducted during service hours are important, as they give us an opportunity to expeditiously identify and resolve issues that may only surface when the system is operating under real-world operating loads."
This includes ensuring accurate train-to-platform door alignment at stations, smooth acceleration and deceleration, as well as interface with the North-South Line, said the LTA in a statement.
During testing, commuters may encounter train and platform doors not opening or closing promptly, trains staying at stations longer than usual, or trains stopping momentarily between stations, the LTA and SMRT warned.
At a press briefing held at a signalling simulation centre in Bishan Depot yesterday, LTA project director Tan Yih Long said the first phase of the centre opened this month, and the second phase will open by the year end.
Mr Tan said the simulation centre allows software issues to be identified and located quickly during the testing of the CBTC system.
The centre, he said, is able to "reproduce problems in the field", and engineers will be able to "stress-test the full system" without having to go down to the tracks.
The system, set up by signalling contractor Thales for an undisclosed sum, was customised for the North-South and East-West lines.
Asked why this simulation centre was not set up before resignalling on the North-South Line started, Mr Tan said that "at the time, the capability was not at this level" yet.
He said, however, that the simulation centre may not have been able to prevent glitches that caused problems last year. These included prolonged disruptions and a collision at Joo Koon station which injured at least 30 passengers. He said this was because many of last year's issues had to do with having the new and old system running at the same time.
Using the simulator has allowed SMRT to correct a software glitch which caused a slight misalignment when trains moved to the depot after service hours.