The Land Transport Authority (LTA) and SBS Transit (SBST) would like to provide an update on our investigations into the power fault incidents along the North East Line (NEL) and Sengkang-Punggol LRT (SPLRT) on 12 and 15 August 2025.

12 August 2025 Incident

2.        The Sengkang Depot Substation has two interconnected switchboards (see diagram) which serve as backups for each other.

3.        On 12 August, two faults were encountered at the voltage transformer for Switchboard 2. The first involved a high current surge due to a fault in the voltage transformer. The second was a dislodged cable connecting to the voltage transformer. In a normal situation, the first fault would have triggered the fuse in the voltage transformer and cut off electric current. However, in this situation, the dislodged cable came into contact with the metallic surface of the voltage transformer panel and allowed electric current to continue to flow, despite the fuse having been blown. The high current surge damaged Switchboard 2. 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, power supply to parts of the NEL and the SPLRT was cut off. The above “double fault” scenario is rare, and we are working on how to eliminate a recurrence in the future.

4.        The NEL and SPLRT services were progressively restored on the same day using a backup power supply. Due to the extensive damage, Switchboard 2 could not be repaired immediately. As Switchboard 1 was protected from damage, it was reconnected to allow normal service to resume the next morning.

5.        LTA and SBST worked together with their contractors to ensure that repairs to the voltage transformer and Switchboard 2 were carried out expeditiously and safely. These were completed on 16 August.

Flow of Incident

15 August 2025 Incident

6.        On 15 August, a power cable fault occurred between Farmway and Kupang stations on the Sengkang LRT. In normal circumstances, Switchboard 2 at Sengkang Depot Substation could have been used to provide backup power, but since it was still out of service from the incident on 12 August, the power cable fault caused the entire network to lose power. Service progressively resumed during the afternoon after power was restored. Some time was required as we had to complete the safe detraining of all passengers first.

7.        LTA and SBST are still investigating the cause of the cable fault. Engineers from LTA and SBST are also testing the cables along the entire SPLRT network to assess their condition. These tests on around 28km of cables is expected to be completed by 23 August, as they can only be carried out during engineering hours.

Next Steps

8.        As part of the Sengkang Depot expansion works, LTA will be implementing a secondary power supply source directly from the SP Power Grid, which will be completed by 4Q2025. For the longer term, LTA is also working with SBST to make further upgrades to the power supply for the NEL and SPLRT.

9.        We thank our commuters for their patience and understanding.