The Land Transport Authority (LTA) and rail operator SBS Transit are working to improve the power system for the North East Line (NEL) and Sengkang–Punggol LRT (SPLRT) following two major train disruptions caused by power fault incidents on Aug 12 and Aug 15.
In a joint statement on Aug 16, LTA and SBS Transit gave updates on the investigations into the power fault incidents along the NEL and SPLRT on Aug 12 and Aug 15.
Image: Screengrab from SGTrains
On Aug 12, both NEL and SPLRT were disrupted at around 11am, with the NEL recovering at around 2:10pm and SPLRT fully resuming services after 9pm.
SGTrains received the first train disruption alert from an LTA data feed at 11:29am, which we had displayed on our Train Service Status web page.
The SPLRT was disrupted for the second time during the morning peak hours on Aug 15 at around 8:40am, with LRT services fully resuming at around 12:54pm. SGTrains received the first train disruption alert from an LTA data feed at 8:59am.
North East Line, Sengkang-Punggol LRT power fault on Aug 12
The joint statement by LTA and SBS Transit said the Sengkang Depot power substation has two interconnected switchboards, which serve as backups for each other.
At the voltage transformer for Switchboard 2, two faults were encountered on Aug 12: The first being a high current surge due to a fault in the voltage transformer, and the second being a dislodged cable connecting to the voltage transformer.
Image: LTA, SBS Transit
In a normal situation, the joint statement said the first fault “would have” triggered the fuse in the voltage transformer and cut off the electric current.
LTA and SBS Transit said, in this situation, the dislodged cable “came into contact” with the metallic surface of the voltage transformer panel and allowed electric current to continue flowing, despite the fuse having been blown.
This caused Switchboard 2 to be damaged by the high current surge, and as the two switchboards were connected, the high current surge from the fault caused Switchboard 1 to disconnect from the system to avoid damage.
With Switchboard 2 damaged and Switchboard 1 disconnected, this caused the power supply to 11 stations on the NEL and the entire SPLRT to be cut off.
“The above ‘double fault’ scenario is rare, and we are working on how to eliminate a recurrence in the future,” said the joint statement.
Free regular and free bridging buses were available for commuters during the train disruption on Aug 12. (Image: SGTrains)
Train services on the NEL and SPLRT were progressively restored on the same day, around three to five hours after it began, using the backup Dhoby Ghaut power substation.
Switchboard 2 could not be repaired immediately due to the extensive damage, said LTA and SBS Transit, adding that Switchboard 1 was protected from damage and was reconnected to allow normal service to resume the next morning.
LTA and SBS Transit worked with contractors to expeditiously and safely repair the voltage transformer and Switchboard 2 on Aug 16.
Sengkang-Punggol LRT power fault on Aug 15
Image: Screengrab from SGTrains
The LTA and SBS Transit joint statement said a power cable fault occurred on Aug 15 between Farmway and Kupang stations on the Sengkang LRT west loop.
“In normal circumstances, Switchboard 2 at Sengkang Depot power substation could have been used to provide backup power,” said LTA and SBS Transit.
However, Switchboard 2 was still out of service from the earlier Aug 12 incident, and the power cable fault caused the entire SPLRT to lose electrical power. Some time was required to complete the safe detraining of all passengers from the stalled LRT trains.
Train services on the SPLRT resumed around four hours after they first began, after power was restored.
LTA and SBS Transit said they are still investigating the cause of the cable fault, and engineers from are also testing the cables along the entire SPLRT to assess their condition.
These tests on around 28km of power cables are expected to be completed by Aug 23, as they can only be carried out after train services have ended for the day.
Secondary power supply source at Sengkang Depot will be implemented by the end of 2025
LTA said that as part of the Sengkang Depot expansion works, which started in 2022, it will be implementing a secondary power supply source directly from the national power grid, which will be completed by the fourth quarter of 2025.
“For the longer term, LTA is also working with SBS Transit to make further upgrades to the power supply for the NEL and SPLRT.”
Related Links
Train Service Status – SGTrains
North East Line – SGTrains
Sengkang LRT – SGTrains
Punggol LRT – SGTrains
External Links
“Joint Action by LTA and SBST to Address Recent North East Line and Sengkang-Punggol LRT disruptions” – LTA/Facebook
Images: SGTrains, LTA, SBS Transit.
This article first appeared on SGTrains.
This is a companion discussion topic for the original entry at https://blog.sgtrains.com/2025/08/nel-splrt-disruptions-lta-sbs-transit-working-to-improve-power-system-after-rare-double-fault/