Commuters breathed a sigh of relief that a warning about more train delays last night did not materialise, following chaos during the morning rush hour when two separate lines were disrupted for about three hours.
Both SMRT's North-South Line and SBS Transit's Downtown Line were hit by signalling faults occurring at around the same time, as people were hurrying to get to work, or school during examination season.
In the case of the North-South Line, a defective train added travel time of up to 45 minutes between Marina South Pier and Sembawang, beginning at around 6.30am. Normal service resumed around 9.20am.
The disruption followed a two- hour slowdown just hours before, during the Thursday evening peak.
In a statement, the Land Transport Authority said the fault may have been caused by erroneous signals being transmitted by the defective train to the line's signalling system. Because signals could not be transmitted correctly, the trains had to be driven more slowly for safety reasons.
The Straits Times understands that Thursday night's delays may also have been linked to this defective train, which has been pulled from service.
Meanwhile, the other rail operator, SBS Transit, said in a tweet at 6.25am that there was no train service on the Downtown Line, also due to a signalling fault. Trains began running again, but more slowly, at around 7am. Service was back to normal by about 9am.
SBS Transit said in a statement that "trains could not be launched automatically from the depot to the main line and had to be manually driven". "The first train started service at 5.37am, seven minutes later than scheduled, at DT1 Bukit Panjang station," it added. "As trains were progressively put into service, this resulted in an additional travelling time of about 15 minutes."
It also said that it is investigating the cause of the signalling fault.
At 4.53pm, SMRT said in a Facebook post that commuters planning to travel on the North-South Line "this evening are advised to plan their journeys ahead", and that "some additional train travelling time may be necessary".
However, checks on the SMRT and SBS Twitter feeds in the evening showed that there were no delays.
National University of Singapore transport researcher Lee Der Horng said it was "unfortunate" these two delays had happened simultaneously.
"I believe they were independent events that were not correlated," said Dr Lee, who said he understood why Singaporeans would be frustrated, given that they do not have alternative train lines to take in the event of delays or breakdowns, unlike in cities such as Tokyo.
Some students taking exams who were held up received time chits showing when they entered and left the train system from SMRT, and the Singapore Examinations and Assessment Board was informed of the delay.
The Ministry of Education said in a Facebook post that arrangements would also be made for Primary 6 pupils taking their PSLE oral examinations, who were delayed on the way to school. Fewer than 10 candidates taking the PSLE oral examination yesterday reported late due to the train disruption, said the examinations board.
The disruptions caused some commuters to arrive at work up to an hour later than usual.
Administrative staff member Nur Naqeeyah, 18, said she has been caught in train delays "quite often", but they had never been this serious.
Sales manager Low Fang Ling, 28, who was travelling from Toh Tuck, said she was delayed for around half an hour as she had to seek an alternative route to work in the Somerset area. She said she has been caught in delays quite frequently over the last two years.
During the disruptions, free bus rides and bus bridging services were available for commuters to continue their journeys.
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Crowds at MRT stations due to train delays. str.sg/4r59