SMRT CEO and top management in charge of engineering maintenance should get fired. But Chee Hong Tat will not as he can always put the blame to SMRT or even LTA and can even score points with a few directives lines like " I have instructed LTA to do a thorough investigation and to ensure such incidents will not happen again..." and continue to collect his million-dollar salaries.
Btw, this is the second major incident in recent weeks. Previous breakdown at CCL is equally bad and there was a failure in adherence to maintenance protocol..:\
https://www.straitstimes.com/singap...ed-during-sept-17-circle-line-disruption-smrt
Maintenance protocol breached during Sept 17 Circle Line disruption: SMRT
SMRT said that the disruption was first caused by a circuit breaker in the Traction Safety Shutdown System on the Circle Line that tripped. PHOTO: SMRT/FACEBOOK
Updated Sep 27, 2024, 02:19 AM
SINGAPORE – The power fault that prolonged the
disruption of the entire Circle Line (CCL) service on Sept 17 was caused by a maintenance team that did not get clearance to replace a circuit breaker during service hours, said rail operator SMRT.
In a Facebook post on Sept 26, SMRT said that the disruption was first caused by a circuit breaker in the Traction Safety Shutdown System (TSSS) on the CCL that tripped.
It took longer than normal to resume operations that evening because SMRT’s maintenance team triggered a power trip on a second circuit breaker in the system when it wanted to replace the main circuit breaker.
The team had wanted to replace the main circuit breaker to prevent the fault from happening again and affecting the work of withdrawing the trains to the depot later that day.
However, the team did not have the necessary permission to perform the needed corrective maintenance work during service hours, according to SMRT. This was a breach of the operator’s standard protocol.
The incident caused the operator to spend additional time to ensure that there were no further technical issues before resuming normal train services.
“For the safety of our commuters, the Operations Control Centre had to account for all trains before normal services could resume. Learning from previous incidents, we activated diversion plans and advised commuters to continue their journeys using other MRT lines or buses,” SMRT said in its social media post.
During the disruption, a technical glitch caused the public announcement (PA) system to be down for 12 minutes. The PA system informs travellers of the alternative MRT lines or buses available during a service disruption.
In the Facebook post, SMRT also provided an update on the
CCL disruption that happened on Sept 18. It said that the root cause of the fire that started in a TSSS cubicle at Kim Chuan Depot is still under investigation.
The fire was detected at about 8pm, SMRT added. This, in turn, triggered the Global Emergency Shutdown (GES) system, which is a built-in safety feature, to automatically shut down the entire line.
SMRT is working with the Land Transport Authority to review the overall design of the TSSS and GES systems involved in the back-to-back disruptions on the CCL.
In addition, the CCL’s signalling and public address systems will also be enhanced, SMRT said. The signalling system is used to direct rail traffic and ensure that trains maintain a safe distance from one another.
“System improvements will be made, including enhancements to Circle Line’s signalling and PA systems, as well as fail-safe and new fail-soft features. Procurement for a replacement TSSS cubicle, with enhanced features, is being expedited,” the post said.
The Straits Times has contacted the operator to get more details about the areas under review and planned improvements.
The CCL was the least reliable among five MRT lines in the 12 months ending March 2024. It is also the only one that posted a dip in performance.
The Thomson-East Coast Line, which has not fully opened, is not included in this measure.
On Oct 14, 2020, the
disruption of train services on the North-South, East-West and Circle lines for more than three hours was partly exacerbated by SMRT staff.
A circuit breaker failure caused a secondary protection system to trip, cutting off power supply from the Tuas Depot substation. This affected stations on the North-South and East-West lines (NSEWL).
Train service between Woodlands and Jurong East stations on the NSL and between Queenstown and Gul Circle stations on the EWL was shut down.
SMRT subsequently decided to draw power from another substation, which supplies power to the CCL.
An SMRT staff member and supervisor misread equipment at the substation and wrongly assumed the fault in Tuas had been isolated.
Failure to isolate the fault before drawing power led to a voltage dip at the Buona Vista substation, causing a power trip and a second disruption that affected service between HarbourFront and Serangoon stations on the CCL.
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