Services on the North-South Line were delayed after an engineering vehicle derailed at Bishan Depot on Feb 7, 2025. - Photo: ST
SINGAPORE: In the wake of three delays on the North-South, North East and Circle MRT lines over a span of five days, the Land Transport Authority (LTA) said it is working with rail operators SMRT and SBS Transit (SBST) to improve their incident response and identify the root causes.
Rail services during the morning peak hours were delayed on Feb 7, 10 and 11. The three incidents are unrelated, LTA said in a statement on Thursday (Feb 13).
Releasing its early investigation findings, it added that it takes a serious view of the incidents.
LTA noted that on Feb 7, an engineering vehicle broke down at a railway crossing in Bishan Depot at 5.15am after completing routine maintenance works.
When operator SMRT tried to move the stalled engineering vehicle using a rescue train, some of the wheels of the engineering vehicle “came off the rails”, LTA said.
The derailed vehicle prevented trains serving the North-South Line (NSL) from leaving the depot.
Hence, to ensure that the NSL could start operations, SMRT redirected some trains from the East-West Line to the NSL.
This allowed train services on the two rail lines to operate throughout the day, but with a longer interval between trains at peak hours, LTA said.
In social media posts on Feb 7, SMRT told passengers on the NSL and EWL to add up to 20 minutes to their morning commutes, as the interval between trains on both rail lines was temporarily raised to up to five minutes that morning.
The typical peak-hour frequency between 7am and 9am is one train every two to three minutes.
While normal train service later resumed at about 9.30am and off-peak train services were unaffected, train journeys during the evening peak period were also delayed briefly as efforts to recover the derailed vehicle took a longer time.
SMRT said then that there was not enough space around the depot’s tracks to use a heavy lifting crane. So a hydraulic jack was deployed to shift the derailed wagon “inch by inch” onto another track at the depot.
After more than 12 hours, the stalled engineering vehicle was cleared by 5.30pm, LTA said. SMRT was able to successfully launch trains from Bishan Depot at about 6.35pm.
LTA noted on Feb 13 that SMRT had provided free regular and bridging bus services along the stretch between Woodlands and Bishan to augment train capacity on the NSL during the morning peak period on Feb 7.
“LTA and SMRT are conducting a thorough investigation into the root cause of this incident,” the authority said.
LTA also reiterated an earlier statement by SMRT, emphasising that the Feb 7 engineering vehicle derailment is completely different from the major EWL disruption that happened in September 2024.
The authority noted that in the earlier incident, which downed services along a stretch of the EWL between Jurong East and Buona Vista for six days, an empty passenger train had derailed while it was returning to the depot.
Turning to the incident on Feb 10, LTA said a signalling fault near Buangkok station at 6.08am caused trains to travel slower on the North East Line (NEL).
Operator SBS Transit provided free regular and bridging bus services between Punggol Coast and Dhoby Ghaut until normal train services resumed progressively from 8am.
LTA said early investigations indicate that the incident was due to a malfunctioning electronic card, which led to a fault in the signalling equipment.
It said SBS Transit replaced the faulty card on the morning of Feb 10, and the component has been sent to French company Alstom, the system manufacturer, for further examination.
During the incident, NEL passengers were told to expect delays of up to 30 minutes due to the signalling fault.
Finally, on Feb 11, a signalling fault happened between Paya Lebar and Marymount stations on the SMRT-operated Circle Line (CCL) at 8.15am.
LTA said this caused a power trip affecting 17 trains. Power was later restored.
While restoring train operations, SMRT found that the central automatic train supervision system - which regulates the movement of driverless trains - was less responsive than usual. This caused a further delay on the CCL.
LTA said the last time there was a similar issue with this supervision system was in September 2024.
Over the last few months, the authority and SMRT have been working with system manufacturer Alstom to develop a software patch.
The patch is scheduled to be deployed on the weekend of Feb 15, after the completion of rigorous testing, said LTA. - The Straits Times/ANN
