Written Reply to Parliamentary Question on Cause of 3 June MRT Disruption and Efforts to Improve Handling of Future Incidents

Mr Alex Yam Ziming asked the Minister for Transport

a. what have investigations into the MRT disruption on 3 June 2024 found to be the cause of the power traction failure;

b. whether current lightning protection for the MRT system is adequate;

c. how can future occurrences of such disruptions be prevented;

d. what are the contingencies for such major incidents; and

e. whether the Ministry will accede to providing more transport options for residents of Yew Tee and Limbang estates.

Mr Lim Biow Chuan asked the Minister for Transport whether the Ministry regularly reviews the communication and crowd control measures adopted by the public transport operators to notify commuters affected by breakdown of MRT trains.

Reply by Minister for Transport Chee Hong Tat:

1. My reply will address Questions Nos 88 and 89, as well as Written Question No 70 for today's sitting.

2. The investigation into the disruption on the North-South Line on 3 June 2024 is ongoing. We have established that a lightning strike damaged an outdoor trackside power control box near Kranji station at around 5.46pm. Based on LTA's preliminary investigation, the surge arrester that was designed to protect the power control box against lightning strikes did not operate as intended. This caused a loss of traction power, and the disruption to train service.

3. The current lightning protection systems for our MRT network comply with local and international standards, to ensure the safety of our commuters. Until this incident on 3 June 2024, there had been no train disruptions due to lightning strikes in the past five years.

4. The operator had adhered to the maintenance regime recommended by the manufacturer for the surge arrester. It is possible that past lightning strikes had accelerated the deterioration of this particular surge arrester, as this section of track between Kranji and Marsiling is lightning prone. Arising from this incident, we are working with the manufacturer and the rail operators to review the maintenance frequency of surge arresters. We have replaced the surge arrester in question, and the other surge arresters in the vicinity have been checked and found to be in working condition.

5. LTA mandates that rail operators have in place robust response plans in the case of service disruptions. These plans include providing alternative transportation options, such as free bus boarding at affected stations and bridging bus services. LTA, rail operators, and other relevant agencies jointly exercise these plans annually. Learning points from incidents and exercises help LTA and our operators to make continual improvements to their incident response plans.

6. For the 3 June disruption, LTA has assessed that the operator had responded in accordance with the standard operating procedures. Nevertheless, LTA has taken note of the feedback arising from the disruption, and are working with the rail operators to strengthen their incident management plans. These include improving the clarity of public announcements during service disruptions, and improving crowd control measures for affected MRT stations and at boarding points for bridging buses.

7. Mr Alex Yam asked transport options for Yew Tee and Limbang. Yew Tee and Limbang residents are served by the North-South Line at Yew Tee station, and are also connected to the East-West Line and Downtown Line by bus services. By the mid-2030s, Yew Tee and Limbang residents will have better access to the Downtown Line when it is extended beyond Bukit Panjang station towards a new Sungei Kadut interchange station.