Tuas West train service suspended until Sunday; Khaw 'disturbed' by software glitch that led to collision

Hannah Teoh
Senior Content Producer
Joo Koon MRT station after a train collision on 15 November 2017. (Photo: Hannah Teoh / Yahoo News Singapore)

The Land Transport Authority said on Thursday (16 Nov) that train service on the Tuas West Extension would resume next Monday, and that the old and new signalling systems on the East-West Line would be isolated “for up to one month”.

The software glitch that led to the train collision at Joo Koon MRT came about when the faulty train “was transiting between the old and new signalling systems”, the LTA said in its statement.

The finding has prompted LTA and SMRT to isolate the signalling system at the Tuas West Extension while investigations are ongoing. The Tuas West Extension runs on the new signalling system while the rest of the East-West Line runs on the old signalling system.

The number of people injured in the collision rose from 29 to 36 after more cases were reported at hospitals, according to LTA and SMRT.

The first train was found to have departed Ulu Pandan Depot with a software protection feature but this was removed when it passed by a faulty signalling circuit. Consequently, the second train misjudged the distance between the two, thereby causing the collision.

While train service on the Tuas West Extension between Gul Circle and Tuas Link stations is suspended, the rest of the East-West Line will continue to run on the old signalling system between Pasir Ris and Joo Koon.

Bridging bus services will be available between Joo Koon and Gul Circle MRT stations when the Tuas West Extension resumes service on Monday. LTA and SMRT are continuing to investigate the incident together with French firm Thales, which supplies the signalling system.

The Tuas West extension serves as many as 100,000 commuters daily and was expected to cut down travelling time by 30 minutes for those working in Tuas.

Bridging bus services at Tuas West Extension. Source: LTA

Khaw ‘disturbed’ by findings

Transport Minister Khaw Boon Wan said in a separate media statement on the same evening that he was “disturbed by the finding that a critical safety software could be disabled by a defective trackside device”.

“I have told the team to keep separating the two sections of EWL, if need be until the entire EWL is ready to run on the new signalling system. This way we avoid having trains transiting from one signalling system to another with its attendant safety risk,” said Khaw.

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