Train services on the Bukit Panjang LRT were fully restored yesterday afternoon, after going off-track for almost 24 hours.
At about 1pm, services running in a clockwise direction from Senja to Petir stations on the 14-station line resumed. At around 5.30pm, services in the opposite direction restarted.
Operator SMRT is giving commuters free rides on the Bukit Panjang LRT from the time service resumed till noon today.
During the disruption, commuters were given free rides on shuttle buses running parallel to the train route, as well as on regular buses calling at station bus stops.
Still, some complained about the inconvenience.
One of them, Ms Jessica Tan, 44, a part-time trainee teacher, took urgent leave to get her daughter to school on time.
The suspension of LRT service started on Monday evening after a fire broke out at an electrical room in Senja station at 5.45pm.
Preliminary investigations indicate that a tie-breaker overheated and caught fire. A tie-breaker is an electrical circuit breaker that connects two sectors of the power rail, and is used to supply power to the train.
A picture of the charred electrical box and other components surrounding the device was posted on Facebook by Transport Minister Lui Tuck Yew, who visited the station yesterday morning.
He wrote that the device had just been installed on Sunday to replace one that had "arcing problems". "Arcing" is an electrical discharge that jumps across a gap in a connection.
As investigations continue into the causes of the fire, The Straits Times understands that it could have been started by a faulty circuit breaker. The burnt component has been sent to a laboratory for study.
One theory being explored is that the electrical system could have been overtaxed as more trains were added to the system, and the newer trains deployed are heavier and draw more power. But this is still being studied, sources said.
The Straits Times understands that SMRT needs time to source the replacement parts. Meanwhile, it will bypass the burnt circuit breaker.
Professor Liew Ah Choy from the National University of Singapore's electrical and computer engineering department said that, in general, tie-breakers are like fuses and serve the function of "opening" or "tripping" when there is an abnormality in power. "By bypassing it, you lose the protective element in that circuit."
SMRT said 20 train cars were tested on the system following the bypass to ensure it ran safely.
Mr Lui said on Facebook that the "overall health" of the LRT system will be reviewed by a joint team from the Land Transport Authority and SMRT.
Commuters frustrated by lack of reliability
The Bukit Panjang LRT Line, which opened in 1999, had 50 disruptions in its first three years of operations.
Over the years, the line's lack of reliability has been a source of frustration for commuters. In the first nine months of last year, there were 59 incidents of delays.
Here is a list of the system's major disruptions:
Nov 19, 2000: A moving train rammed into a stationary train at Phoenix station, injuring three passengers. Operator SMRT was fined $10,000 for the accident, caused by an employee overriding a safety warning.
Oct 21, 2002: About 900m of track was damaged, after a wheel fell off a train. It took about five days for services to resume. SMRT was fined $10,000.
May 12, 2004: Services were down for four hours, following a series of power trips.
Nov 30, 2010: A power fault resulted in a two-hour disruption, affecting some 5,000 commuters. Four trains stalled and 88 passengers were forced to walk up to 300m to the nearest stations.
April 22, 2012: Due to a stalled train, 11 passengers had to walk on the tracks to Senja station. Train services took about 2½ hours to fully resume.
April 2, 2013: Forty passengers had to walk from a stalled train to the nearby Phoenix station, due to a power trip which disrupted services for more than an hour.
July 4, 2013: Human error resulted in a a stalled train blocking the depot exit routes. SMRT was fined $60,000 for launching a train on the wrong route and delaying train service.
Feb 24, 2015: A power and signal collecting assembly of a train got dislodged, hitting a signal rail and causing a power trip, resulting in an hour-long delay.
This article was first published on March 11, 2015.
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