Train services on the Thomson-East Coast Line (TEL) were disrupted for five hours yesterday morning due to a signalling fault.

In a Facebook post in the afternoon, rail operator SMRT said the fault was caused by a software glitch in the signalling system's network component.

As a result, the component had to be reconfigured before the system could be reset. The reconfiguration was carried out by engineers from systems supplier Alstom. "After completing our pre-operations start-up protocol, normal train services commenced," said SMRT.

The breakdown was first announced at 5.43am and lasted until 10.56am. Services at the three stations on the line typically begin at about 5.40am every day.

In an update at 7.02am on Twitter, SMRT said train services between Woodlands North and Woodlands South stations remained down, and free regular and bridging bus services were available. With Woodlands interchange between the two, this is stage one of the TEL, which has been open since Jan 31.

SMRT tweeted at 11.27am that the free bus services had ceased.

"We are sorry for affecting your commute this morning," SMRT added on Facebook.

It said in-train and station announcements were made to inform commuters of the delay and of the availability of the free bus services connecting the three stations.

SMRT also said it deployed more than 20 of its staff on-site to assist affected commuters.

This was the second breakdown this year on a new MRT line. In October, a damaged power cable between Tuas Link and Tuas West Road stations on the East-West Line (EWL) led to a series of events that caused major service disruptions which also affected the North-South Line and Circle Line.

The two stations are part of a four-station extension to the EWL that opened in June 2017.

Transport Minister Ong Ye Kung said in September that the com-pletion of the six stations in the second stage of the TEL will be delayed by three months to the first quarter of next year because of the impact of Covid-19. The stations were initially scheduled to open late this year.

Since July 30, services on stage one of the TEL have been ending earlier at 9pm daily and starting later at 6.30am on Saturdays and Sundays for SMRT to "continue testing of the integrated systems and trains in preparation for the opening of stage two" of the line. The early closures and later openings were slated to end on Aug 30, but have since been extended to Dec 31.