[ad_1]
SINGAPORE: Train services on three MRT lines were disrupted overnight on October 14 due to simultaneous power failures, affecting 15 trains and 123,000 passengers.
The electric trip affected the North-South Line (NSL) between Woodlands and Jurong East stations, the East-West Line (EWL) between Queenstown and Gul Circle stations, and the Circle Line between Serangoon and HarbourFront stations.
As a result, passengers had to be evacuated from stopped trains and asked to walk on the tracks to return to nearby stations. Bus stops also filled up as travelers rushed to continue their trips by alternative means.
Here’s how the events unfolded:
6.58 pm
A breakdown of the insulation of a power cable between the Tuas Link and Tuas West Road stations caused a power outage at the NSL and EWL. This caused 12 trains to stop at the sections of the viaduct between stations.
The train’s lighting and air conditioning were also affected. The backup battery on the affected trains was automatically activated to provide emergency lighting and mechanical ventilation, the Land Transportation Authority (LTA) said.
Services between Woodlands and Jurong East on the NSL and between Queenstown and Gul Circle on the EWL were discontinued.
Crowds enter a bridge bus at the Buona Vista MRT station after a power failure disrupted train services on several lines on October 14, 2020 (Photo: Christy Yip).
Crowds waiting for buses at Clementi MRT station after a power failure disrupted train services on several lines on October 14, 2020 (Photo: Ang Hwee Min).
Free regular bus and bridge bus services were made available.
To maintain train services at unaffected stations, trains were changed at nearby stations. Single line train shuttle services were implemented between Marsiling and Woodlands stations on the NSL, as well as between Dover and Queenstown on the EWL.
To restore power to both lines, an attempt was made to extract power from the Buona Vista intake substation. SMRT said that as this was done “without first isolating the fault,” there was a power outage on the Circle Line, which is also served by the substation.
READ: Train services resume on North-South, East-West, Circle lines after disruption due to power failure
7.34 pm
A second power outage occurred, affecting service on the Circle line between Serangoon and HarbourFront.
Three trains stopped in the tunnels with passengers on board.
Trains turned around at Serangoon and Tai Seng stations toward Stadium to continue serving unaffected sections of the Circle Line.
7.38 pm
After assessing that the power supply could not be restored quickly, SMRT initiated passenger disembarkation on the affected NSL and EWL trains. To protect personnel and travelers, electrical protection devices were installed to prevent the traction power from being accidentally switched on.
Passengers on a train near Kranji on the North-South Line to Woodlands were evacuated after a power failure disrupted MRT service on several lines on October 14, 2020 (Photo: Julie Chan).
7.53 pm
The derailment began for the 12 trains stopped at the NSL and EWL. SMRT personnel walked along the tracks to reach the stopped trains and check on the well-being of the passengers on board, as well as to assist and guide them back to the nearest station.
7.59PM
The derailment began for the three stopped trains on the Circle Line.
8 pm
Power supply was restored on the Circle Line after power was drawn from Bishan Depot Intake. However, the restoration of traction power was prevented for safety reasons, as the derailment of the passengers had already begun.
Crowds at the Buona Vista MRT station after a power failure disrupted train services on several lines on October 14, 2020 (Photo: Christy Yip).
8.17 pm
Bypass for commuters on the Circle Line completed.
8.42 pm
The discharge concluded for travelers on the NSL and EWL, with the exception of a train near Bukit Batok station. The download was delayed due to inclement weather and the risk of lightning.
8.43 pm
Train services along the Circle Line progressively resumed after security checks were completed, about an hour after the outage was reported. Approximately 13,000 commuters were affected, including 275 who were traveling on the trains.
9.32 pm
SMRT announced on Twitter that free scheduled bus and bridge bus services for the affected Circle Line stations had ceased.
9.43 pm
The discharge was concluded for the train that stopped near Bukit Batok station. The more than 70 passengers who had remained on board until traction power was restored in the sector alighted directly on the station platform.
10.34 pm
Train services on the NSL and EWL were progressively restored after security checks, more than three and a half hours after the outage was reported.
The disruption on these two lines only affected about 110,000 travelers, including about 6,500 who had been on the trains.
READ: Power cable insulation failure started a chain of events leading to MRT – SMRT service interruption
EARLY OCTOBER 15
In site investigations conducted during engineering hours, a 22 kV cable section located about 400 m from the Tuas Link station was found to have burned out.
The faulty trigger coil and faulty wires have since been replaced, LTA said.
Later that day, a maintenance crew inspected all the stations in the West Tuas Extension to make sure the trip coils for the circuit breakers were working.
Two were found to exhibit inconsistent performance and were replaced. The defective coils were later sent for further forensic investigation.
OCTOBER
The replacement work for the affected power cables was scheduled to begin.
NOVEMBER
Contractor Alstom agreed to replace all 22kV cables after the October 14 outage. To ensure that power cable failures do not cause another service interruption, the 113 trip coils along the Tuas West expansion will also be replaced.
The Land Transportation Authority will implement weekly early closings beginning in November so that the replacement of the firing coils can be completed before the end of the year.
Early closings or late openings will also be scheduled on weekends or full closings on Sundays in 2021 to facilitate physical cable replacement jobs.
Additionally, SMRT will increase the frequency of checks of the 22 kV trip coils and circuit breakers while replacement work is being performed.
