Financial Penalty of $3 Million Imposed on SMRT

          The Land Transport Authority (LTA) has completed its investigations into the root cause of the train service disruption on the East-West Line (EWL) between Jurong East and Buona Vista stations that occurred from 25 to 30 September 2024.

2.        On 25 September 2024, a dislodged axle box caused the wheels of the third train-car of a Kawasaki Heavy Industries (KHI) train to fall off the track, damaging the EWL tracks between Dover station and Ulu Pandan Depot. Repair works were carried out over six days and full services resumed on 1 October 2024. LTA was assisted by an Expert Advisory Panel (EAP) in its investigation and also commissioned SGS Testing and Control Services Pte Ltd (SGS) to conduct an independent forensic analysis of the axle box failure.

Summary of Findings

3.        The recovered axle box and axle bearings were badly damaged, and the grease in the axle box had completely burnt off. The recovered chevron spring debris was also too badly damaged for any tests to be done to identify any initial damage prior to the incident. It was therefore not possible to establish a definitive root cause.

4.        The investigations concluded that a likely cause of the failure was degraded grease in the axle box, which can increase wear and tear on the axle bearings, eventually causing overheating and failure. This conclusion is supported by the presence and location of burnt rubber and metal pieces from the chevron springs found along the incident train’s path of movement. This suggested that the axle box had generated sufficient heat to burn the rubber of the chevron springs. The chevron springs then progressively dropped off and eventually caused the axle box to dislodge. The sequence of events was further substantiated by the Hot Axle Box Detection System (HABDS), an additional monitoring tool put in place by SMRT on their own initiative to detect high temperatures to alert maintenance staff to potential issues on axle boxes. The HABDS had detected elevated temperatures on one of the axle boxes of the incident train prior to the incident.

Maintenance Regime

5.        The incident train was part of the 66-train first-generation KHI fleet that is progressively being replaced by new Movia trains. Initially, 66 Movia trains were to be handed over to SMRT by March 2024, with the first trains to be handed over in October 2021.  Due to the COVID-19 pandemic, there was a delay of 1.5 years, and the first Movia train was only handed over to SMRT in May 2023. SMRT began decommissioning the KHI trains upon receiving the first Movia trains. SMRT was required to continue carrying out regular maintenance for the KHI trains that were still in service, including conducting preventive maintenance and overhaul.

6.        Regular preventive maintenance carried out by SMRT on the incident train, including on 10 September 2024, found no anomalies with its axle box assemblies. The incident train was last overhauled in 2018, and had logged 690,000 km since its last overhaul in 2018. SMRT had twice extended the overhaul interval for the incident train beyond its stipulated maintenance requirement of 500,000km, to 575,000 km in August 2022, and to 750,000 km in August 2024. These extensions were carried out based on SMRT’s internal procedures, and SMRT had relied on analysis of the performance of the KHI train fleet and their continued reliability in deciding on these extensions of the overhaul intervals for the incident train. As axle box failures are not common, SMRT did not undertake a detailed engineering and risk assessment on extending the axle box overhaul interval. Based on the updated timeline for the replacement of KHI trains, in December 2023, SMRT had commenced a cycle of modular overhaul for 38 KHI trains that were still in service and required overhaul of their safety critical components, including the incident train. By the time of the incident on 25 September 2024, 18 had been overhauled, but the Incident Train had not. Had the incident train been overhauled in a more timely manner, the condition of its axle box assemblies would have been checked and any degraded grease could have been replaced earlier.

Penalty Proportionate to Incident’s Circumstances

7.        LTA intends to impose a financial penalty of $3 million on SMRT. In determining the penalty quantum, LTA took into consideration that SMRT had borne the cost of repairs, and provision of free bridging buses and regular bus services, as well as shuttle train services at the affected stations. It also provided free travel to passengers alighting at Jurong East and Buona Vista stations for the six days of disruption. The total costs amounted to over $10 million.

8.        The financial penalty collected will go to the Public Transport Fund to help lower-income families with their public transport expenditures.

Lessons Learned

9.        LTA and SMRT have incorporated lessons from the EWL disruption to improve the mitigation and management of major disruptions, to ensure that affected commuters will be able to continue their journeys as quickly as possible.

10.       After the incident, SMRT pre-emptively withdrew all KHI trains that had exceeded 500,000 km mileage since their last overhaul from service to undergo overhaul activities for axle boxes before they were put back into service. This was completed in October 2024. LTA has also developed an accelerated delivery programme for new Movia trains with the support of additional resources from SMRT and various contractors, to mitigate the delays from COVID-19, which will allow all KHI trains to be decommissioned by third quarter-2025.

11.       In consultation with LTA, SMRT has implemented the use of data analytics for earlier detection of abnormal axle box temperatures, so that pre-emptive action can be taken before problems occur. As asset owner, LTA has also strengthened its oversight of operators’ management of assets, including operators’ internal procedures to adjust maintenance schedules. LTA and operators will work together for future overhaul decisions.

12.        SMRT, LTA, and the National Transport Workers’ Union have set up a tripartite Rail Safety and Reliability Review Workgroup to review and enhance systems in areas such as life cycle management, asset renewal, system enhancements, and maintenance practices across the rail ecosystem. As part of the review, the workgroup has engaged overseas metro operators in Guangzhou and Taipei for mutual learning.

13.       In the medium-term, as announced at MOT’s Committee of Supply 2025, to support tripartite efforts to strengthen rail reliability, the Government intends to invest up to an additional $1 billion over the next five years to enhance the management of rail assets and improve the capabilities of the rail workforce. This includes putting in place more comprehensive condition monitoring capabilities, which allow for more proactive and targeted maintenance, across our rail network. This will complement investments to carry out targeted pre-emptive replacements of subsystems and components to better sustain our assets.

14.       For more details on the investigation findings and follow-up actions taken, please refer to the report.


Annex:  Diagrams and Photos