Mechanics spent nearly two hours fixing railway points at Hua Lamphong subway station after an "unexpected" system failure caused delays that affected hundreds of morning commuters during Monday's morning rush hour.
The incident occurred about 7.30am when passengers queued up at Hua Lamphong began to notice a delay, which consequently stranded commuters who wanted to avoid traffic.
Passengers were unable to travel as officials had to close Hua Lamphong and the adjacent Sam Yan station while repairs were conducted. Service resumed at 10.15am.
"This problem was unexpected," Transport Minister Arkhom Termpittayapaisith said after an inspection.
He insisted subway officials run routine checks every day, their work meets strict standards and the issue with the railway points was more complex than they had expected.
The points are very important to trains coming from Bang Sue station as they have to change tracks in order to return to Bang Sue.
Subway supervisor Mass Rapid Transit Authority (MRTA) was aware of the impact that extended to many stations on the 20km route. The MRTA had to implement a temporary plan to divide the route into two sections -- from Bang Sue to Rama IX station and from Rama IX to Silom station -- to keep services at those stations operational, said MRTA governor Peerayudh Singpatanakul.
Despite this measure, he admitted the number of train trips was reduced.
To deal with such a situation, officials need to provide affected passengers with other types of public transport to better serve their needs, Mr Arkhom said.
The problem occurred on the same day Bangkok Expressway & Metro Plc, which was contracted by the MRTA to run subway services, held a drill to address brake issues experienced by a packed train on a section of track between the Huai Kwang and Thailand Cultural Centre stations.