Most commuters on the North- South Line (NSL) were unfazed when their train journey came to a scheduled stop yesterday for about 10 minutes.
At about 11.10pm, the 30 trains in service stopped running to allow for the network to be switched over to an upgraded signalling system.
The switchover was completed at about 11.20pm.
This was the first test of the new communications-based train control system by the Land Transport Authority and train operator SMRT during passenger service hours.
The new system is due to replace the current fixed-block signalling system used on the 30-year-old NSL, but no date has been set yet.
The new signalling system will allow trains to run at faster intervals of 100 seconds, instead of the current 120 seconds.
When The Straits Times visited Toa Payoh station at about 10.45pm, SMRT staff were giving out complimentary train ride tickets. These tickets, valid for a single trip on all SMRT lines until December next year, were given out from 10.30pm as a gesture of goodwill for commuters affected by the stoppage.
During the switchover, announcements were made at all 26 NSL stations and in the trains while SMRT service staff assisted affected commuters.
Student Clarence Chu, 21, was annoyed by the interruption. "I understand this is necessary but I'm quite unhappy. I'm trying to get home so I can get work done."
Others were more relaxed about the brief delay. A 30-year-old hotel cleaner, who gave her name only as Ms Xing, said in Mandarin: "I'll just wait it out because it's quite normal for trains to stop sometimes."
Mr Siu Yow Wee, SMRT's director for station operations for the North-South and East-West lines, said a second test is likely to be carried out on Thursday.
Earlier in the evening, a fault affected the same line. At about 9pm, SMRT tweeted that there was a signalling fault at Sembawang station and commuters were told to allow for an additional 15 minutes in travelling time from Bishan towards Sembawang.