Passengers on the East-West Line had their morning commute delayed again yesterday, after the same track circuit between Jurong East and Clementi developed a fault for the second day in a row.
Operator SMRT took almost two hours to rectify the fault, which began at 7.50am and caused travel time for commuters heading east from Joo Koon to nearly double.
An SMRT spokesman said trains going between Joo Koon and Clementi had to travel at slower speeds owing to the faulty track circuit, which is used to track and control the speed of trains.
Trains also stopped frequently between stations, only to start moving again several seconds later, commuters said.
SMRT turned several west-bound trains back towards Pasir Ris at Clementi and Jurong East, to reduce the waiting time for commuters at other stations.
Normal service resumed at about 10am. However, trains between Pioneer and Jurong East were still moving slowly for another half an hour owing to the earlier congestion.
On Tuesday, the same faulty track circuit caused delays of up to 30 minutes for commuters.
SMRT said its engineering staff examined the track circuit last night to determine the root cause of the latest fault. Repair work was carried out on Tuesday to fix the track circuit, it said.
Salesman Ong Wei Jun, 31, said he boarded the train at Boon Lay at 9.50am and expected to reach Clementi on time for work. However, his travel time doubled from the usual 10 minutes to more than 20 minutes.
"The train was very slow today," he said. "I'm very late for work. There was no warning, no announcement at the station. If I knew, I would definitely have taken a bus instead."
In a blog post yesterday, Transport Minister Khaw Boon Wan noted that both trains and track-side systems are significant causes of disruptions. To tackle this, more trains will be progressively added, while existing systems are being restored and upgraded, he said.
He added that he is now "more optimistic" about knowing what needs to be done to improve rail reliability, but also warned about "wild cards" - incidents caused by unforeseen factors.
"To battle the unknowns, we also have to build up an army of experts with years of experience. This takes time, but we are determined to get there," he said.