Thales looks for root cause of Metro line shutdown

Major disruptions to the LRT’s Metro line last Friday seem to have been caused by malfunctioning equipment that created an “extremely rare ‘network broadcast storm,’ ” the company responsible for its signal system says.

Thales Canada, contracted by the City of Edmonton to set-up the Metro line’s signalling system, apologized to LRT riders in a statement for the difficult commute on a very cold day. Temperatures reached a high of only -20 C, with a low of -26 C, according to Environment Canada, and that’s without factoring in windchill.

A preliminary investigation found the malfunction took place in third-party equipment that is part of its communications-based train control system, which allows trains to communicate where they are along the line, Thales said. A broadcast storm occurs when a network is overloaded by continuous electronic traffic.

The company said the storm overloaded the line’s central network, stopping it from properly communicating to trains if they could safely travel from one station to another.

“At no time was safety compromised. If a train can’t proceed safely then the safe thing for the train to do is not to proceed,” said Dave Beckley, Thales’s vice-president of commercial operations and customer service.

Beckley said Thales was able to find the piece of malfunctioning equipment but is still determining what caused the device to fail.

Thales won the bid to build the new signalling system in 2011. Work on the system was originally expected to be completed in 2013 but has faced years of delay. The city issued a notice of default against Thales last May, giving the company until Dec. 4, 2018 to finish working out any remaining issues.

“This type of disruption is unacceptable to Thales and we are working diligently with ETS to determine the root cause of this occurrence,” Cara Salci, Thales’s national director of public affairs and communications, said in the statement. “While Friday’s event was frustrating and disruptive, the reliability of the Metro line has been exceptional over the past 14 months.”

The city is conducting tests on the system, with LRT representatives saying previously that Edmontonians can expect an average of 1.5 days of line closures each month due to the testing.