(The following article by Greg Gormick was posted on the Toronto Star website on February 2.)
TORONTO — These have been tough times for trains and train riders in the GTA.
Since the beginning of December, glitches in field components of Canadian National’s computer-driven rail traffic control system have shut it down on seven occasions and stopped trains dead in their tracks west of Toronto, three times during the commuter rush hours.
Snow and ice have jammed track switches on both the CN and Canadian Pacific main lines to the east, north and west of the city, leading to delays and even cancellations of the GO trains that shuttle thousands of commuters to and from their downtown jobs.
Six serious freight train derailments ? the worst of which claimed two lives ? occurred in Ontario last month despite the multi-million-dollar investments made by CN and the CPR in high-tech devices such as hot wheel, hot bearing and dragging-equipment detectors.
At least for the moment, it appears that advanced technology has failed the iron horse.
Yet one low-tech element of the GTA rail system has not failed: the 76-year-old electro-mechanical signalling system operating most of the track network at Toronto Union Station.
Signals are the heart of rail operations. It is the red, green and yellow lights that tell crews whether it’s go, or no go.
“We’ve had our share of problems,” says Derrick Dewar, supervisor of operations and safety for the Toronto Terminals Railway (TTR), which operates the downtown rail plant on behalf of owner GO Transit, referring to January delays. “We had a major problem last Thursday, when a track switch machine failed in a key location. Ironically, it was one of the newest ones. But there have been no delays due to what is the oldest and most vital element in the whole plant.”
About 200 GO Transit and VIA Rail trains roll along the tracks leading into Union Station every weekday, all of them under the control of this 1928-vintage signalling system.
As the warning system for whatever else goes wrong, the signals ? whose job is to keep trains a safe distance from each other ? can’t fail.
And although last week’s delays left many commuters fuming, they also proved the worth of the vintage system’s interlocking “fail-safe” system.
Take Thursday morning’s mechanical failure that disabled a key track switch on one of principle routes into Union Station.
Because the switch wouldn’t respond properly to the command from the John St. signal tower, the interlocking system that controls the whole operation couldn’t use that switch as part of its internal jigsaw puzzle. It locked the route out.
Although this reduced the capacity of the tracks in and out of Union and snarled rush hour operations, the control gear did what it was designed to do: it failed safe.
The fact that this industrial museum piece is still functioning reliably under this winter’s adverse conditions is a source of pride to the employees of the Toronto Terminals Railway. The ruggedness and reliability of this Roaring ’20s control gear is one reason it’s still used in one of Canada’s most vital transportation facilities, says Dewar, a 35-year veteran of the TTR
“The system hasn’t been kept in service for history’s sake. It’s because we can count on it to perform and keep the GO and VIA operations fluid. If it was prone to failure and it regularly delayed those trains, you’d be inconveniencing a large portion of the commuter population of the whole GTA. But this system still runs like a top.”
Union Station’s train traffic volume is the most intense in Canada even though, at a little less than 6 kilometres, the TTR is one of Canada’s shortest railways in terms of route distance. It encompasses the area from the Don River in the east to Strachan Avenue and Old Fort York in the west. Packed into this compact facility are 6.5 km of station platforms, 42 km of track, 142 track switches and 234 signals located beside or above the tracks.
The system that controls this thicket of tracks, switches and signals is known as interlocking ? an adjective that has become a noun in the quirky vernacular of railroading. One long-out-of-print handbook defines this long-out-of-production system as “a set of signals and signal appliances connected together so that their movements follow each other in a predetermined, successive order.”
TTR employees who work with this system say the easiest way to understand it is to think of the Union Station track grid as a giant jigsaw puzzle that is attached to machines that duplicate this puzzle in miniature. As in an interlocking puzzle, a railway interlocking demands that each piece must mate with the other pieces that surround it in order to complete the picture correctly and clear a pathway for a train to move across it. Just as putting the wrong piece in the wrong place makes it impossible to complete a puzzle, setting the wrong track switch or signal prevents the creation of a complete train routing picture and brings the process to a halt.
Despite its reliability and blemish-free record, this technological museum piece is living on borrowed time. There are plans on the boards to replace it with an advanced computer control system. The big advantage will be a reduction in the manpower needed to operate it and maintain the ancient equipment.
Parts no longer exist in many cases and must be custom manufactured in-house by specialized TTR craftspeople. The reason it hasn’t already been shunted aside is due to its replacement cost and the technological complexity of not just designing, but also installing a digital equivalent.
“We’ve allocated $377 million for a thorough rebuilding of the entire Union Station Rail Corridor,” says Greg Percy, director of rail operations for GO Transit. “Of that, $260 million will go for a new signalling system that will include microprocessor-based replacements for the electro-mechanical interlockers in the three towers. It’s going to take at least until 2013 to design, build and install it.”
Percy also points out that the task before the designers of the new rail traffic control system for Union Station will be to create the system alongside the existing one while the trains continue to roll. The old and new signalling systems will have to be completely operational at the same time.
Says Percy, “The electro-mechanical interlocking system can’t be removed until the new one has been tested and fully proved while the trains continue to roll. And we can’t shut it down to do the work unimpeded by train movements.
“The most you can hope for is a few hours at night or on weekends, when you can get a clear block of work time. In a tight, interwoven rail terminal like this, this is going to require airtight project planning and `out of the box’ engineering design.”
Understandably, the TTR employees have grown fond of the 76-year-old equipment that will vanish within the next decade. Some are not convinced that new will be better.
The westernmost section of the Union Station complex is already computer controlled and, the employees say, not yet as reliable as the interlocking machines.
They also point to the glitches that brought down CN’s brand new southern Ontario digital rail traffic control system in recent weeks as evidence of the fallibility of much of the so-called state-of-the-art rail traffic control technology.
“It’s inevitable that it (the old machinery) will vanish,” says the TTR’s Dewar. “We all hope some of the equipment will wind up going to a museum, so future generations can see what a technical marvel it really is.”