Rail operator SMRT was yesterday told by the Land Transport Authority (LTA) to check all service maintenance doors, after a fault in one of them led to a 30-minute halt in train services between Queenstown and Bugis MRT stations yesterday morning.
Train services in both directions on the East-West Line had to be stopped from 11.30am to allow SMRT technicians to dismantle the unhinged service door near Tiong Bahru station.
The sliding door separating the east- and west-bound tunnels along the line had somehow become dislodged from its roller rail.
Whenever a train passed, the resulting air turbulence caused the faulty door to flap, allowing its bottom to come into contact with the power-supplying third rail. This caused intermittent power trips, The Straits Times understands.
Get The Straits Times
newsletters in your inbox
"We decided to remove the door as it was faster than repairing it," an LTA spokesman said. "This allowed train services to resume as quickly as possible."
The power trips started at about 6am. Each time, SMRT had to reset the system, and this caused delays and crowding on station platforms across the North-South and East- West lines. This was further aggravated later by a track circuit fault on the East-West Line.
Regular bus services were made free of charge at the affected stations. "We are very sorry for the inconvenience," train operator SMRT said on its Facebook page.
A large crowd was seen at a bus stop near Queenstown station, as commuters searched for alternative modes of transport to continue their journey.
The power trips started at about 6am. Each time, SMRT had to reset the system, and this caused delays and crowding on station platforms across the North-South and East-West lines. This was further aggravated later by a track circuit fault on the East-West Line.
Ms Crystal Yeow, a part-time promoter, was waiting for 20 minutes for a friend who had to alight from a train en route to their meeting point at City Hall to take a bus.
"I understand that some disruptions cannot be helped, but in the long run, it is not good for the economy because of the loss of productivity," said the 49-year-old.
Yesterday's train delays began from as early as 6am, with several commuters claiming they were stuck at Lakeside MRT station.
In a tweet at 7.26am, SMRT said trains were running at longer intervals due to an "intermittent power fault", adding that crowds were expected at stations.
The East-West Line was also hit by a track circuit fault at Commonwealth station later in the morning, with SMRT tweeting at 8.51am to warn of delays of up to 15 minutes for commuters travelling from Joo Koon to Commonwealth stations. It subsequently revised the estimate to 20 minutes at 9.33am.
Commuters who responded to the tweets, however, said the delays lasted at least 30 minutes.
Secretary Jesse Francis, 40, told The Straits Times that her normal commute from Jurong East to Queenstown took almost an hour instead of the usual 15 minutes.
"This is really out of the blue. I would normally take a taxi if I were expecting any delays," she said.
Train services returned to normal yesterday afternoon and ran without problems in the evening peak.
The latest incidents came barely 12 hours after a door obstruction at Newton station caused delays on the North-South Line during the evening peak on Monday.
A power fault last occurred on July 12, affecting train services on both lines late at night.
Last Friday, a signalling fault caused trains to stop in between stations for over 15 minutes on the Circle Line at around 10pm. Temporary clamps which came loose near Choa Chu Kang station on the North-South Line also caused delays earlier that day.
SMRT said it was still investigating those other glitches, but emphasised they were not related to the new signalling system on the North-South Line. It said it was also checking other components that might have come loose along the line and will investigate why the door became unhinged.
LTA said in a statement yesterday: "As a precautionary measure, the LTA has asked SMRT to do a system-wide check on all the service maintenance doors. We are investigating the cause of the loosened door to prevent it from recurring."
• Additional reporting by Lee Min Kok and Lim Min Zhang