LTA probes root causes of MRT disruptions after 3 incidents in week

The Land Transport Authority (LTA) has said that they are working closely together with rail operators SMRT and SBS Transit to identify the root causes of the three MRT disruptions in less than a week.

In a statement on Thursday (Feb 13), LTA said the peak-hour disruptions on Feb 7, 10 and 11 to the North-South Line (NSL), North East Line (NEL) and Circle Line respectively, are unrelated.

The service disruption on the NSL began at about 5.15am when an engineering vehicle broke down at a railway crossing in Bishan Depot after completing routine maintenance works.

This prevented trains from being launched from Bishan Depot into passenger service.

"When SMRT tried to move the stalled vehicle using a rescue train, some of the wheels of the engineering vehicle came off the rails," said LTA.

LTA said that SMRT then redirected some trains from the East-West Line to the NSL to ensure that the latter could commence operations.

This allowed train services to operate throughout the day on both lines, with a longer interval between trains during peak hours, they added.

Normal service progressively resumed after the stalled engineering vehicle was cleared by 5.30pm, allowing SMRT to launch trains from Bishan Depot.

"LTA and SMRT are conducting a thorough investigation into the root cause of this incident," the authority said.

Signalling fault behind NEL disruption

As for the Feb 10 disruption on the NEL, LTA said that it was caused by a signalling fault near Buangkok station at 6.08am, which resulted in trains travelling slower. 

During the incident, SBS Transit provided free regular and bridging bus services between Punggol Coast and Dhoby Ghaut.

Normal train services then resumed progressively from 8.00am.

"Preliminary investigations indicate that the incident was due to a fault in the signalling equipment, caused by a malfunctioning electronic card," said LTA. "SBS Transit replaced the malfunctioning electronic card on the same morning and restored the system's operations.

LTA added that the malfunctioning component was sent to system manufacturer Alstom for further examination.

Power trip affected 17 trains on Circle Line

Then on Feb 11, there was another signalling fault, this time between Paya Lebar and Marymount stations on the Circle Line at 8.15am.

This caused a power trip which affected 17 trains and caused delays to the morning commute.

Power was subsequently restored and train movement progressively resumed at 8.20am, said LTA.

"When restoring operations, SMRT observed that the Central Automatic Train Supervision (CATS) System, which regulates the movement of driverless trains, was less responsive than usual," said LTA, adding that this caused a delay to normal operations resuming that day.

According to LTA, the last time they experienced an issue on the CATS system was in September 2024.

"LTA and SMRT have been working with Alstom, who is the system manufacturer, over the past few months to develop a software patch," said LTA. "The patch is scheduled to be deployed this weekend, following the completion of rigorous testing."

chingshijie@asiaone.com

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