Written Reply by Minister for Transport Khaw Boon Wan to Parliamentary Question on Investigation into Joo Koon MRT Train Incident

Dr Lim Wee Kiak asked the Minister for Transport 

a.     whether he can give an update on the Ministry's investigation into the Joo Koon MRT train accident;

b.     what are the lessons learnt and the steps taken to prevent such incidents; and

c.     how serious are the injuries of those injured and whether any person is suffering from a long-term effect of the injuries.

Reply by Minister for Transport Khaw Boon Wan:

1.     LTA completed detailed investigations and released a summary of its findings on 18 Dec 2017. These are consistent with initial findings reported a few days after the collision on 15 Nov 2017. 

2.     The root cause of the collision was a software logic issue with the new Communications-Based Train Control, or CBTC, signalling system. It failed to anticipate and hence could not handle a specific confluence of failure conditions. These conditions, in turn, occurred as a result of complications from operating two signalling systems concurrently on a single line - the new CBTC system on the Tuas West Extension and the old legacy signalling system on the rest of the East-West Line.

3.     The signalling system supplier, Thales, has rectified the system to address the failure conditions which led to the collision. In addition, Thales will set up a CBTC simulation facility in Singapore to strengthen the CBTC testing process. The facility will enable LTA and SMRT to perform additional simulation tests in a controlled setting which is tailored to our local environment and the infrastructural conditions of our rail network, before deploying it on our train services. 

4.     As a precautionary measure, we further decided to separate the CBTC operations on the Tuas West Extension from the rest of the East-West Line. The separation will continue until the rest of the East-West Line has fully transitioned to the new CBTC signalling system. Meanwhile, we are speeding up the re-signalling project and the extended engineering hours from MRT early closures and late openings will enable us to complete this transition by the middle of this year. 

5.     A total of 37 passengers, including four SMRT staff, sustained injuries from the Nov 15 collision. All were discharged from hospital within a week of the incident, with most discharged on the same day. 10 require outpatient follow-up treatment and SMRT is in touch with them to provide all necessary support. We expect a full recovery.