Joo Koon MRT collision: Faulty train was transiting between old and new signalling systems

SINGAPORE – A faulty train transiting between the old and new rail signalling systems at Joo Koon station on Wednesday (Nov 15) morning led the train behind it to move forward and hit it, said the Land Transport Authority (LTA) on Thursday.

The old signalling system currently operates from Pasir Ris to Pioneer, while the new system – which allows trains to arrive more frequently during peak hours – operates from Joo Koon to Tuas Link. The new system is supplied by French multinational firm Thales.

Given the finding, Transport Minister Khaw Boon Wan instructed the separation of the two sections of the East West Line operating under different signalling systems. This means there will be no train service from Monday between Joo Koon and Gul Circle stations for up to one month. Commuters will be served by bridging buses.

“Although Thales is confident, I am disturbed by the finding that a critical safety software could be disabled by a defective trackside device. Until this concern is fully addressed, we should not resume the link between Tuas West Extension and the rest of the East West Line,” said Mr Khaw to the media. The Tuas West Extension consists of Gul Circle, Tuas Crescent, Tuas West Road and Tuas Link stations.

“I have told the team to keep separating the two sections of East West Line, if need be until the entire (line) 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,” he said.

The isolation of the two signalling systems will allow for assurance checks, said the LTA.

The authorities had said on Wednesday that the faulty train had its software protection feature removed when it passed a faulty signalling circuit along the track.

The removal of the safety feature caused the train that was 10.7m behind at Joo Koon station to detect it as a three-car train and move forward, resulting in the collision that injured 36 people at about 8.20am. The disabling of the safety feature was the first occurrence for Thales anywhere in the world, Mr Peter Tawn, its project manager for the new signalling project in Singapore, had said on Wednesday.

The collision was the first major incident here involving the new signalling system which has already been rolled out on the North South Line.

Mr Khaw had apologised to commuters on Wednesday, saying: “It’s an awful day today. Commuters were inconvenienced, some even injured. We are deeply sorry for that.”