Malfunctioning water-pumping system the cause of train service disruption: LTA

A malfunctioning water-pumping system was the cause of a train-service disruption along the North-South line, said the Land Transport Authority (LTA) on Sunday.

Preliminary investigations found that water had entered the tunnels through the portal opening near Bishan MRT station, where aboveground rail tracks transit underground.

In a statement, LTA said that under normal circumstances, rainwater runoff would have been siphoned off by a system of pumps. The system malfunctioned on Saturday, resulting in rainwater overflowing from the storm water sump pit into the tunnel opening and accumulating at the lowest point of the tunnel, between Bishan and Braddell stations.

As a safety measure, SMRT immediately deactivated the trackside power supply. The pump system has since been repaired. Detailed investigations into the cause of this incident are ongoing.

LTA also said that it is investigating an un-related incident of a small trackside fire in the tunnel between Marina Bay and Raffles Place MRT stations that occurred on Saturday afternoon.

Train services between Newton and Ang Mo Kio MRT stations resumed at 1.50pm on Sunday, about 20 hours after services halted on Saturday evening.

It followed an overnight effort to clear water in the tunnels between Bishan and Braddell MRT stations, brought about by "torrential rain" on Saturday, according to Facebook updates by SMRT.

The post wrote: "Teams from the SCDF, PUB, LTA and SMRT worked jointly to pump out water from the tunnels."

It added that teams from SMRT and LTA also conducted network-wide checks on MRT tunnels.

More than 40 buses from SMRT and SBS Transit were deployed to provide bus bridging services between Newton and Ang Mo Kio. Teams of SMRT staff were seen at bus stops and at the affected MRT stations to help commuters find alternative travel routes and to address other queries.

Thousands of commuters were affected by the disruption on the North-South line since Saturday.