North-East Line disruption: LTA, SBS Transit reviewing measures to strengthen power system's resilience

SINGAPORE: The Land Transport Authority (LTA) and SBS Transit are reviewing measures to strengthen the power system's resilience after an hours-long disruption hit train services on the North-East Line (NEL) and Sengkang-Punggol LRT on Tuesday (Aug 12). 

Train services between 11 stations on the NEL were affected on Tuesday after a power trip occurred at a depot substation. The Sengkang-Punggol LRT service was disrupted as well.

"Based on preliminary investigations LTA conducted with SBS Transit, a fault had occurred in the switchboards which fed power to the system," said the transport authority in a Facebook post on Wednesday. 

"There are two switchboards that act as backups for each other. Normally, if one trips, the other can continue supplying power from the main source."

However, during Tuesday's fault, the first switchboard was damaged and the surge triggered a safety feature that shut down the second switchboard to protect it from damage, said LTA. 

This also cut off the main power supply from Sengkang Depot.

As a result, SBS Transit had to manually connect the backup power source from Dhoby Ghaut to the second switchboard to restore services progressively.

“As part of post-incident follow-up, LTA and SBS Transit are also reviewing measures to strengthen our power system’s resilience,” said the transport authority. 

DISRUPTION 

Tuesday's disruption was announced by SBS Transit at around 11.30am, stating that train services between Farrer Park and Punggol Coast MRT stations on the NEL and the entire Sengkang-Punggol LRT were affected. 

Power was progressively restored to the affected stations, and NEL services fully resumed at 2.10pm.

However, services on the Sengkang-Punggol LRT were down for about five hours. 

SBS Transit Group CEO Jeffrey Sim said that recovery works for the LRT service had to be carried out in stages to ensure a steady increase of the electrical load and prevent another power trip, as both the NEL and Sengkang-Punggol LRT were now relying on a shared substation. 

Power on the Sengkang LRT was restored at 3.34pm, while Punggol LRT had begun progressively resuming services from 4.15pm. 

However, to avoid stressing the power supply from the single substation, services on the Sengkang-Punggol LRT operated on a single track for both the east and west loops during the evening peak periods. 

Full services on the LRT were resumed as of 9.20pm. 

Acting Transport Minister Jeffrey Siow expressed disappointment last week at the rail disruptions in the last few months.

In July and August, services were disrupted on the East-West Line (EWL), Thomson-East Coast Line (TEL) and Bukit Panjang LRT. The EWL, TEL and Bukit Panjang LRT are operated by SMRT.