Bishan tunnel flooding


The Bishan tunnel flooding was a major incident on the North South MRT line of the Singapore MRT which occurred at 5.33 pm on 7 October 2017. The flooding of the tunnels between the Bishan and Braddell MRT stations was caused by heavy rain and a faulty maintenance pump. The flooding of the tunnels made the passage impassable, and bridging bus services had to be deployed while the Singapore Civil Defence Force and maintenance staff removed the water from the tunnel. The incident caused more than S$2 million in damages and lost revenue for the operator SMRT and led to the firing of eight maintenance employees.

Background

The section of flooded tunnels between Bishan and Braddell was part of the first section of the system to open. At the time of the incident, the system was going through a turbulent period plagued with multiple disruptions and delays which caused much public displeasure, and this incident further aggravated the situation. Earlier in the day, there was a lunchtime delay on the North East line, and in the previous month, service on the Bukit Panjang LRT line was disrupted.

Incident

At 5.33 p.m. on 7 October 2017, heavy rain flooded the tunnels between the Bishan and Braddell MRT stations. In addition, a small trackside fire, whose cause is still unknown, was spotted by a train driver between the Raffles Place MRT station and the Marina Bay MRT station. This prompted the trains operator, SMRT, to suspend all service from Ang Mo Kio to Marina South Pier. SMRT provided free bridging buses along the affected stretch of stations.
At 7.07 p.m., the Singapore Civil Defence Force received a call from SMRT about a flooding situation in the tunnels between the two affected stations. SMRT then officially reported the flooding on social media at 7.30 p.m. Train service between the Newton MRT station and Marina South Pier was restored, but service between Newton and Ang Mo Kio remained down. SMRT also mentioned that its engineers were working with SCDF personnel to pump water out of the affected stretch of tunnels. At 1.50 p.m. the next day, SMRT said that the water had been cleared and that service would resume, and test trains were deployed to ensure passenger safety. This resulted in almost 20 hours of disruption.

Investigation

Following the incident, SMRT and the Land Transport Authority launched a joint investigation into the incident. The initial report delivered by the LTA listed three possible causes for the failure. The investigation led to the uncovering of falsified maintenance records and lack of maintenance of the water pumps.

Aftermath

As a result of the incident, SMRT suffered S$2 million in damage to trackside equipment and trains. The incident prompted a check of other similar pumps around the system, two of which, at Lavender and Kembangan, were also found to be faulty. SMRT also fired eight employees from their maintenance crew — including a senior executive, two managers, and five members of the technical staff — as a result of the incident.