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.