SINGAPORE - Transport operator SMRT will commence "live" testing of its new signalling system on the East-West Line (EWL) on five Sundays from this Sunday (April 29) to May 27, according to the Land Transport Authority (LTA).

During the 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 end-May, 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 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 train operational hours. All 35 stations along the EWL have had their operating hours on weekends shortened since March 2, so as to provide more time for engineering staff to intensify testing of the new signalling system.

The last shortened hours on the EWL will be April 29.

Commenting on the live testing, 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 included ensuring accurate train-to-platform door alignment at East-West Line stations, smooth acceleration and deceleration of trains along tunnels and viaducts along the East-West Line, as well as the interface with North-South Line (NSL) operations, said LTA in a statement.

The LTA and SMRT warned commuters that during the live tests, commuters may occasionally encounter instances of train and platform doors not opening or closing promptly, trains being held at stations longer than usual, or trains stopping momentarily between stations.

At a press briefing held at a signalling simulation centre in Bishan Depot on Tuesday (April 24), LTA project director Tan Yih Long said the first phase of the centre was opened this month, and the second phase will open by year end.

Mr Tan said the simulation centre allows software issues to be identified and located quickly during the testing of the new communications-based train control (CBTC) signalling 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, East-West Lines.

Asked why this simulation centre - supposed the largest Thales has built - was not set up before resignalling on the North-South Line, a project fraught with glitches, started, Mr Tan said "at the time, the capability was not at this level" yet.

He said, however, that the simulation centre may not have been able to pick up the glitches which caused the many problems encountered last year.

These include prolonged disruptions and a collision at Joo Koon station which injured at least 30 passengers. Mr Tan said this was because many of last year's problems had to do with having the new and old system running at the same time.

Asked what it had learnt since the simulation centre was set up, the LTA said a software glitch which caused a slight misalignment when trains moved to the depot after service hours was identified and corrected.

The simulation centre is manned by a staff of four full-timers. It can be used as a training centre "to build up local expertise", and can accommodate up to 20 engineers. It will also be used when line extensions or new stations are added to the North-South, East-West Lines.

Transport Minister Khaw Boon Wan visited the centre on Tuesday morning.