City officials pitch alternative signal system for Metro Line LRT
City of Edmonton officials say they have figured out a new way to run Edmonton’s Metro Line LRT if Thales Canada doesn’t meet its new Dec. 4 deadline.
In a report released Thursday afternoon, city officials said Thales Canada proposed that date as its last chance to have the line to NAIT running as designed, restoring full frequency to the original Capital Line. If it makes the deadline, Edmonton officials would then start testing the line, which could last into the new year.
Thales originally committed to finish its work in December 2013.
If Thales doesn’t meet the new deadline, city officials say they’ve already hired alternate consultants and figured out a way to use the old signalling system to run the line, restore frequency and even support expansion into the northwest.
That new technique would: Return the original line to a fiveminute
■ frequency during peak service (Clareview currently misses one train in three to serve the Metro Line);
Allow up to 10-minute frequencies
■ on the Metro Line between Health Sciences Station and NAIT; and
Allow Metro Line trains to run ■ every five minutes after the line extends north toward St. Albert.
But few details were available on just how they intend to accomplish that.
“If (the old system) could do that, why wouldn’t you have done that in the first place?” said Coun. Andrew Knack, hoping for more detail Tuesday.
City officials declined to comment until the plan is presented to council. They issued a notice of default to Thales in May.
TRAIN SIGNALS 101
There are two main types of signalling systems. For decades, Edmonton has used a fixed block system, where a track-side light doesn’t turn green to let a train through until the next section of track, or block, is free.
Thales Canada is attempting to use a new kind of signalling system, called moving block, which it said was necessary to allow trains to pass within 2.5 minutes of each other in the downtown tunnel. Edmonton needs that frequency to let trains on the Metro Line and the Capital Line both operate with five-minute frequencies.
Thales’ moving block system uses radio-wave communication between the trains, and between the track and the train, to keep the trains a safe distance apart.
NO ONE ELSE COULD DO IT
When Edmonton tendered the signalling contract for the Metro Line in 2011, Thales Canada was the only one of five companies to score full marks on the technical requirement to run trains within 2.5 minutes of each other in the tunnel. It was a $45.4 million contract.
Edmonton officials wouldn’t say which company has now been engaged to help it create this alternative signalling system.
Experts have previously said fixed block systems can be retrofitted to allow for higher frequencies if engineers make the safety blocks shorter. But the fact no other company could score full points for frequency in the procurement process suggests that technique alone would not take the city far enough.
The Metro Line is currently running at full speed. But it’s not allowing trains to weave between each other in the tunnel. That means every third train coming from the south has to divert to NAIT. For passengers, that means trains are overcrowded and shorter than usual from the south and there are up to 10-minute waits during peak hours in the north.
North side passengers are frustrated with the ongoing delay and want a solution that ensures any northwest LRT extension doesn’t carry the same signalling problems, said Coun. Jon Dziadyk.
“We’ve definitely given (Thales Canada) a lot of time to prove the concept,” said Coun. Aaron Paquette.
As for Edmonton’s new plan, he said, “administration seems to be pretty confident they can do it.”
Reached Thursday, a Thales Canada official said it will be commenting on the situation shortly. In the past, it has said not all of the delay is the company’s fault.