Loosened bolt caused train platform door to become dislodged

SINGAPORE — The faulty platform screen door on the Downtown Line (DTL) that caused a train delay earlier this month was a result of a bolt that had come loose, causing the door to fall out of place and into contact with the side of an approaching train.

And while an investigation after the incident on Oct 4 found that platform screen doors on the whole were functioning normally, the Land Transport Authority (LTA) and SBS Transit (SBST) have gone back to the original equipment manufacturers of the DTL doors to enhance the design of the door fasteners. These enhanced fasteners will installed on all DTL doors.

“Going forward, more specific checks on all DTL platform screen doors will be done as part of routine maintenance,” the LTA and SBST added in a press release on Tuesday (Oct 18).

On Oct 4, a platform screen door at Sixth Avenue station had dislodged, and trains could not pass through the station towards Chinatown.

The LTA and SBST said a bolt on the fastener that secures the affected platform screen door to the guide rail had “loosened over time”, causing the door to be misaligned and coming into contact with the side of an approaching train. “No commuters were hurt in this incident,” they added.

(The current fastener design; image: SBS Transit/LTA) 

The DTL is the Republic’s newest MRT line, and phase two of the line — where the incident happened — opened to fanfare in December last year.

The LTA and SBST said the platform screen doors at Sixth Avenue station were last checked by SBST in August as part of its routine maintenance, and none were found to be faulty.

Following the incident, all DTL platform screen doors, including bolts and securing mechanisms went through further extensive inspections. “All the platform screen doors were found to be functioning normally. Platform screen doors on the other rail lines were also inspected, and found to be secure and in good working condition,” they added.

(The enhanced fastener design; photo: SBS Transit/LTA)

A self-locking nut and a retaining pin will be added as an additional measure to better secure the fastener to the guiding rail.

“The enhancement works to the doors are expected to be completed in the next two weeks. All platform screen doors for the upcoming DTL3 will also use this enhanced fastener design,” they said.

As for the other rail lines, the LTA and SBST said the platform screen door design is different and will be retained. “(They) have been operating well for some years without any report of loosened mechanical parts,” they added.