Technician’s control room error causes metro trains to shut down
July 29, 2019
A shutdown of Sydney’s new metro rail line on Monday morning was caused by a technician inexplicably breaking the glass on a fire suppression system, triggering gas to be pumped into a control room and forcing its evacuation.
The “serious incident” at 9.20am caused delays for thousands of commuters for the next 90 minutes, forcing stations along the $7.3 billion Metro Northwest line to be evacuated and replacement buses put on to eventually transfer passengers to their destinations.
At the time, 17 driverless trains were running along the 36-kilometre line in both directions between Rouse Hill and Chatswood. Two of the trains were stuck in tunnels for about 15 minutes before they were moved on to stations where passengers could get off and catch buses.
Transport officials initially blamed the shutdown on a “communications system issue”.
But Transport Minister Andrew Constance said the incident was due to “human error”, caused by a technician in the metro line’s control room at Rouse Hill in the city’s north west breaking the glass on a fire suppressant system.
“In breaking the glass, gas was released through the control centre, which led to an evacuation. Because of the very nature of the gas released, it meant there was no oxygen to ensure that people were safe inside the centre,” he said.
Firefighters arrived quickly on the scene. No fire or smoke was detected
Transport systems around the world including Sydney’s have mechanisms in place for critical areas which, in the event of a fire, result in oxygen being sucked out of rooms to suppress flames and protect equipment. Staff are evacuated before their safety is placed at risk.
Mr Constance said he expected the private operator of the metro line to “look closely at this” incident, and details about why the technician activated the suppression system.
“We will always take key lessons out of incidents like this,” he said.
The control centre for the trains is housed in buildings adjacent to a large stabling yard for the line’s fully automated trains at Rouse Hill. Up to 30 people typically work in the control centre.
Transport for NSW secretary Rodd Staples said the system worked “exactly as it was planned and designed”, citing the evacuation of the operations control centre, and the stopping of trains to ensure “that everyone was safe”.
“[It is] important we learn some lessons out of this and the metro operator is certainly looking at that. But the back-up system did come into play and we were able to stand up the system,” he said.
Within an hour of the alarm, a decision was made to shift to the back-up system to allow a gradual recovery of services on the metro rail line.
The delays coincided with the first day of major changes to the bus network in Sydney’s north west, which has linked more bus routes to stations along the metro line but come at the cost of a number of services to the central city including the 610 from Rouse Hill to the CBD.
Mr Constance said the government would continue to monitor the response of commuters to the changes, but cited a drop of up to 25 per cent in patronage on some buses to the CBD as evidence people were switching their travel patterns to use the new metro trains.
“You can’t change services without upsetting someone. At the same time, it’s about the greater good to benefit the majority of people,” he said.
Matt O’Sullivan is the Transport Reporter for The Sydney Morning Herald.