Insulation fault on power cable caused MRT disruption: SMRT preliminary findings

SINGAPORE — In preliminary findings released on Thursday (Oct 15), rail operator SMRT said a breakdown of insulation of a power cable was to blame for a major disruption to train services on Wednesday evening.

Services were disrupted for more than 3.5 hours on the North-South Line (NSL) and East-West Line (EWL) starting about 7pm on Wednesday. Services on the Circle Line were disrupted for about an hour starting from 7.30pm.

In its statement, SMRT said it was “sorry” for the disruption. It said the faulty insulation of a power cable was between Tuas Link and Tuas West Road stations.

“A circuit breaker at Tuas West Road station should have kicked in to isolate the fault, but it did not, resulting in the NSL and EWL power system to trip,” said SMRT.

“To restore power to the NSL and EWL, there was an attempt to draw power from Buona Vista Intake substation (BVI). However, this was done without first isolating the fault, resulting in a power supply disruption to Circle Line as BVI also serves Circle Line.”

A total of 36 stations were affected by the disruption. The stations were from Woodlands to Jurong East, Queenstown to Gul Circle and Harbourfront to Serangoon.

Train service on the Circle Line was restored at 8.40pm, while the NSL and EWL services returned at 10.35pm.

During a doorstop interview on Thursday, Transport Minister Ong Ye Kung said that it was a “rough night” and thanked engineers, technicians, station staff, service ambassadors, home team and bus companies who helped rectify and control the situation.

Mr Ong said he had received “many emails” from commuters who were “actually quite upset” over the disruption to services.

“I'm quite new to this job, but I inherited a very united team, due to years of hard work, whether it is regulator, operator, contractor or off-site security agencies, government agencies, all coming together and really just one purpose: To make sure that our system is in as tip-top condition as possible to serve our commuters,” he said.

”With that I believe we can continue to improve the system.”

“It’s a complex system… so, never be complacent, continue to work hard and work together to make sure the system works as well as possible.”

The insulation fault has been identified and isolated and the faulty component of the circuit breaker has been replaced, said SMRT, adding that train services are running normally on Thursday.

“We are working with the Land Transport Authority to conduct a full investigation into the premature failure of these components, together with the original equipment manufacturers who supplied the parts.”