SINGAPORE: Delays on the Downtown Line on Thursday were caused by a "synchronisation issue between two sets of signalling equipment", said SBS Transit and the Land Transport Authority (LTA) in a joint news release on Friday (Mar 2).

It affected service between Promenade and Downtown stations for the whole of Thursday, with trains having to be driven manually and at a lower speed.



The fault, which occurred at Bayfront station, involved the Temporary Speed Restriction Manager and the Trackside Automatic Train Control System.

The "synchronisation issue" between these two equipment triggered an "automatic safety response from the system", which led to a speed restriction along the affected stretch of the line, said SBS Transit and LTA.

They added that normal train service resumed from the start of service hours on Friday morning, after engineers worked through the night to fix the problem.

"Two track circuits at Bayfront station were manually synchronised. This restored the synchronisation issue between the two sets of signalling equipment," said the joint release.



"We were then able to lift the speed restriction imposed between Promenade and Downtown stations. The team also operated empty test trains through the affected stretch through the night to verify that the issue had been fully resolved."



The supplier of the signalling system, Siemens, will continue to investigate the root cause of the "failed synchronisation" to prevent a repeat of the problem, they added.

