Dufferin: Toronto’s kinkiest street
May 16, 2010
Kenneth Kidd
Jim Schaffner, sporting the requisite hard hat, safety glasses and fluorescent orange vest, is searching for just the right analogy. He finds it in a shoebox.
If you were to take the bottom part of a shoebox, cut out one corner and then place it on the floor, upside down, you’d have something akin to the first section of the partially constructed new underpass at Queen and Dufferin Streets.
Put a brick on top of the cardboard box, and the box will become unstable, wanting to twist and collapse in the direction of the open corner.
Left on its own, this section of the unfinished underpass would react the same way, courtesy of more than 160 freight and commuter trains rumbling over it every weekday.
It wouldn’t be an underpass for long, so preventing its collapse has required a whole set of stop-gap measures.
To keep the structure in place, 32 great steel rods, or tie-backs, have been drilled down at an angle to connect the underlying bedrock with the east wall of the new underpass, next to what will one day carry the northbound traffic of Dufferin.
But the traffic lanes are at this point filled with dozens of temporary reinforced concrete pillars — yet another way of compensating for the weak, open corner.
“We need the columns there to hold up the rail traffic, so we don’t have this severe twist in the underpass,” says Schaffner, senior project engineer, structures and expressways, with the City of Toronto.
Building any new road structure on this scale is a major project, but doing so without blocking car travel on Queen St. or stopping the rail traffic overhead creates serious complications.
The whole $40-milllion project, from its start in late 2008 to its scheduled completion in August, is a Rubik’s Cube of staging and phasing and temporary measures.
Additional land had to be purchased, even an adjacent building partly demolished, to make way for the project.
By the time it’s over, the still-working rail lines above will have been moved twice to allow for excavation. Three rail bridges will have been raised a full metre and another bridge relocated about 10 metres from its original location.
All this to remove the so-called Dufferin Street Jog, the little detour to the east that has delayed and annoyed road travellers for more than a century.
Where Queen St. W. approaches Dufferin, the road dips just past the Gladstone Hotel to travel under a tight package of six bridges of the rail corridor running from downtown Toronto northwest toward The Junction and beyond.
This old underpass, or subway as it was originally called, is lined with walls of massive limestone blocks. On the north side of Queen, there’s a big piece of sculpted limestone.
“Queen St. Subway,” it reads.
Beneath that, in raised lettering, are the names “R.J. Fleming, Mayor” and “E.H. Keating, City Engineer,” followed by the date in large numerals, “1897,” the year of Queen Victoria’s Diamond Jubilee.
The whole structure speaks to a time when civic leaders dreamed in big, Imperial terms, laying the foundation for assumed greatness. Grand flourishes like the Queen Subway were being built for the ages.
What its creators couldn’t foresee was how Dufferin would eventually develop into the sort of major artery that Queen had already become in 1897. Dufferin north of Queen was turning heavily industrial, its factories backing onto the rail lines that would transport their goods.
With the advent of cars and trucks — lots of them — the great wall of the original Queen Subway became an awkward barrier.
If you were travelling north on Dufferin, you’d have to turn right on Queen, then left on Gladstone Avenue, then make another left onto Peel Street before turning right to get back onto the northward continuation of Dufferin.
In other words, precisely the “jog” now being eliminated by an underpass finally connecting the two stretches of Dufferin.
But how to do that when six rail bridges are not just involved but cross Queen awkwardly at a 45-degree angle, the most westerly bridge mostly crossing the soon-to-be unified Dufferin?
And how to do that without stopping cars and trucks from using the intersection?
The key to answering that, it turns out, comes courtesy of the rail industry’s consolidation in the last century.
Skip forward to 2008 and you’ve got six bridges, but only four rail lines running over them, two each for CN Rail and GO Transit’s Georgetown line. Spare bridges can come in handy at times like these; they make staging possible.
By tweaking schedules, what used to run on four lines could be accommodated on just three — half the bridges.
Hence Stage 1, beginning in December, 2008.
The rail lines were redirected over the three western bridges, leaving crews free to excavate the eastern portion of the site and construct the part of the underpass that now resembles the shoebox with a big corner piece missing.
But before they could shift to Stage 2, there was one small matter: relocating the most easterly bridge. In the original configuration, this bridge was much closer to Gladstone. To work with the new underpass, it had to be lifted and moved about 10 metres further along Queen, so that it would sit next to the other eastern bridges.
This happened “on a Sunday morning,” says Schaffner, who, like a lot of engineers, has a way of making this sound like an everyday occurrence. But it left more than a few pedestrians perplexed.
“A lot of people didn’t quite know what had happened when they came on Monday,” he says.
With the bridge moved and a pie-slice portion of the new underpass completed — replete with tie-backs and temporary pillars — all the rail traffic could then be shifted to the three eastern bridges.
By January, 2010, everything was ready for Stage 2 and another set of complications and temporary measures.
The western bridges originally rested on the great limestone wall that ran along the north side of Queen.
It was precisely this wall that had blocked Dufferin’s northward path, the very wall that would have to be demolished to let Dufferin connect with the new underpass.
Before that could happen, though, temporary steel support towers had to be constructed on either side of Queen to hold up the western bridges. But the towers were only built to within roughly 30 centimetres of the bridges to allow for something else to occur.
Huge jacks started raising the bridges, a few centimetres at a time, little additions made to the towers along the way.
“Then they lock them off, reset the jacks, and off they go,” says Schaffner. “That took about a morning, one Saturday morning.”
As he says this, Schaffner is beaming in that Boys Own Weekly manner all engineers seem to possess. As a breed, they’re not prone to saying something can’t be done.
In all, the western bridges were raised by nearly a metre, to increase the overhead clearance for traffic on Dufferin. On the south side, they could be shored up on top of the original limestone wall. Not so at the north end.
The 113-year-old wall on the north side would have to be replaced with a great steel girder in the shape of an archway, one that would let cars and trucks travel through it and into the underpass.
Which is roughly where things stand now.
In behind the archway, crews are busy setting out re-bar and forms for the concrete that will create the final, western portion of the underpass.
The entire structure will become whole, its shoebox weaknesses a thing of the past.
Just to the west of the underpass, some of the stone from the old wall will be incorporated in a parkette shaped like an amphitheatre.
Inside the underpass will be four lanes of traffic, two bike lanes and a little nod to the future.
Just as the Bloor Street Viaduct was built to allow for future subway trains, the concrete base of the underpass is recessed under two of the lanes.
That’s there to accommodate any new streetcar line, the top of whose rails would end up at the same grade as the adjacent traffic lanes. Until then, it will simply be covered in asphalt.
Barring any unexpected delays, the underpass will finally open to traffic in August, but not without a final complication, this one slight but lingering.
“One thing you’ll notice,” says Schaffner, a bit impishly, “is that we haven’t eliminated the jog entirely.” As Dufferin crosses Queen and into the underpass, the road will still veer about 1.5 metres to the east.
The problem is the archway girder and what it has to support.
“Because of the very heavy loads of these rail bridges, with every foot of span (carried by the girder), the depth of that overhead girder gets deeper,” says Schaffner.
Extending the span to get rid of the jog completely wouldn’t leave the desired headroom for the traffic on Dufferin. “So this was the optimum depth of girder and span.”
This thought seems to bring out something wry in Schaffner. “In 113 years,” he says, “there will be another jog elimination project.”
