SMRT worker, supervisor suspended over Oct 14 disruption
They committed error that extended the disruption of NSEW lines to Circle Line, which affected about 123,000 commuters on Oct 14
An SMRT staff member and his supervisor have been suspended after an error exacerbated the three-line train disruption during evening peak on Oct 14.
The worker had misread a graphics display and thought the initial fault, which caused a power outage along sections of the North-South and East-West Lines, had been isolated, said SMRT chief executive Neo Kian Hong yesterday.
This caused a second outage in parts of the Circle Line, worsening the disruption and eventually affected about 123,000 commuters.
At a joint briefing with the Land Transport Authority and systems supplier Alstom to explain what went wrong, Mr Neo said the pair will need to undergo retraining and recertification before they can resume duties.
Human error was one of several issues that plagued the train network that evening. (See infographics on the right.)
Apologising for the disruption, Mr Neo said Alstom has committed to replacing all 150km of power cable along the Tuas West Extension.
This will be completed by the end of next year.
Plans were already in place to replace some of the cables from this month after four similar cable faults were found along the 7.5km-long extension since it opened in 2017.
As an added precaution, Alstom will also replace all 113 trip coils along the extension by the end of this year.
To facilitate the replacements, there will be early closure of stations from next month, as well as late openings or even full-day Sunday closures for limited periods next year. The French company will bear the cost of the works.
It is still investigating the cause of the cable and trip coil faults. A visual check of the malfunctioning circuit breaker on Oct 6 had found no issues.
In the interim, SMRT will increase the frequency of checks on its circuit breakers from once a year to once every six months.
It will also review its power recovery protocols.
Said Mr Neo: "There are lessons to be learnt and we will do better."
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Timeline of events
Oct 14, 6.58pm
- A power outage caused by concurrent faults along the Tuas West Extension shuts down train services between Woodlands and Jurong East stations on the North-South Line and between Queenstown and Gul Circle stations on the East-West Line. This causes 12 trains to stall on the tracks. It also affects in-train lighting and air-conditioning.
- The backup battery on affected trains kicks in to provide emergency lighting and ventilation.
- An attempt to draw power from the Buona Vista substation causes a second power outage, affecting service between HarbourFront and Serangoon stations on the Circle Line.
- Three trains stall as a result.
- SMRT decides to detrain passengers on the stalled trains as it cannot restore power supply quickly.
- As a safety measure, electrical protection devices are installed to guard against the accidental turning on of traction power.
- SMRT staff members walk along the tracks to reach the stalled trains and help commuters.
- NSEWL passengers begin to leave the stalled trains.
- CCL passengers begin to leave the trains.
- Power supply is restored for CCL, but SMRT does not restore traction power along sectors where detrainment is taking place, for safety reasons.
- All stranded CCL passengers reach the nearest stations.
- Passengers from 11 stalled trains on NSEWL reach the nearest stations.
- Train services along CCL progressively resume.
- Detrainment of the last train near Bukit Batok station is temporarily halted due to rain and lightning risk, with 78 passengers still on board.
- The 78 passengers reach Bukit Batok station.
- Train services are progressively restored on the NSEWL.