What is still (very)
good at Turcot
By Pieter Sijpkes
In this chapter
alternatives to the two main parts of the plan for the Turcot Interchange and
Turcot Yards put forward by the Ministθre des transports du Quιbec
(MTQ) will be outlined.
These counter-proposals
were developed this winter at McGill University when my second-year
architecture students and I looked into the opportunities and problems related
to the Interchange and the Yards.
The chapter is divided into
four sections: a summary; a counter proposal for the repair (rather than the
proposed demolition) of the Turcot interchange; a counter proposal to modify
the MTQs plans to reduce the Falaise St Jacques to a highway embankment
and; a final section in which all Montrealers are encouraged to visit and
survey the Turcot area in person. For those who prefer to stay in their
armchairs, I provide you with a short walking tour, in words, of my own recent
visit to this extraordinary place.
Proposed Entrance Pavilion and Belvedere, overlooking the Turcot
Interchange and Yards from Terry Fox Park. Designed by student Anne-Marie
Nguyen.
Summary
This stage in the course of
events surrounding the Turcot Yards project can be compared to the time when
things went wrong with the Apollo 13 mission.
The pivotal moment in that
mission came when its crew was asked by ground control to focus on what was
still good on the ship rather than on what went wrong. We are at a similar
pivotal point in the 40-year saga of
the Turcot Interchange and Turcot yards, and so I ask What is still good at Turcot?
The MTQ project is informed
by two major decisions, both of which should be reviewed from an Apollo mission
perspective. The first decision is that the many spans of the Turcot
Interchange (and the associated dAgrignon and de la Verendrye sections) should
be torn down and replaced by "lowered" structures.
I argue that a
repair-in-place option should be revisited. Repair-in-place of the viaducts
would not require expropriation of housing units, would preserve the many
hectares of useful land below the structures, and would eliminate the permanent
scarring and dividing of neighbourhoods with embankments.
The second MTQ decision is
to move highway 20 and the CN tracks towards the Falaise St. Jacques. This plan is reckless and expensive. The
highway and the tracks are fine where they are (straight and on grade) and how they are (in good condition). There is
no need to open up at great expense 100 hectares of developable land that are
already opened up. Instead, the Falaise
St. Jacques could be widened into a real and unique linear park, and it and
part of the restored St. Pierre River could be protected from highway noise by
a simple landscaped berm. The
remaining land could then be used for what it is well suitedtrain shunting and maintenance, and
truck-rail transfer activities. (This would have the additional humanly
beneficial effect of making neighbourhoods like Point St. Charles and Cote St.
Luc less noisy as such rail activities were moved away from them.)
Unlike the single plan
presented by the MTQ, the similar Alaskan Way Viaduct case in Seattle has for years seen experts and the
general public alike rigorously debate as many as ten options. Importantly, a
repair-in-place option was recently given new life with the commission of a
$150,000 independent study from the
prestigious engineering firm T.Y. Lin. Regardless of the outcome of this effort, it shows a
commendable openness to other points of view.
The lives of the Apollo 13
crew were saved by focusing on what was still good on their craft; the
environment and the pocketbooks of Montrealers will no doubt benefit from a
similar change in focus in the MTQ Turcot strategy.
Counterproposal 1
The ups and downs of the Turcot Interchange: a repair option
outline
Elevation
of a typical Turcot span after repair
Graphic
by Stuart Kinmond
The construction of the
Turcot interchange coincides with my arrival in Montreal in 1966. I saw the
concrete being poured; I rode across the interchange in a borrowed car the day
it opened. And there was a lot more fresh concrete curing in Montreal at that
time. Luigi Nervi's Place Victoria had just been declared the highest concrete
high-rise in the world, Ray Affleck's Place Bonaventure, the first real
mega-building on earth was being denuded of its formwork, and Moishe Safdie's
boxes of Habitat '67 were just settling in on top of each other.
The Turcot Interchange
looming high above the black landscape on its hundred-foot stilts, lit by two
parallel, continuous bands of built-in fluorescent lights, fit very well into
this brave new world.
However, the "alien
landing lights" were gone after two years (aluminum wiring and aluminum
casing do not last long when splashed with salt water in winter). And, the
concrete of the interchange soon showed signs of distress.
Reinforced concrete, when
soaked for prolonged periods in water (salt or not) will absorb it to a certain depth. If this
depth is more than the thickness of concrete covering the reinforcing bars (two
or three inches), these bars start to rust. When steel rusts it expands in
volume about ten times. Once water gets in, "rust inflation" will
soon push away concrete covering it, exposing yet more steel to the corrosive
influence of salt water. ("Spalling" is the technical term for this
process).
The Turcot interchange was
very tightly designedthere are no shoulders, so snow cannot be pushed to the side to
clear the road, and lots of road salt has been used to keep the easily frozen,
exposed spans navigable. The brine resulting from this process has flowed like
a river down the sloping roadways, not easily finding drains. Expansion joints
(planned "cracks" in the structure to allow it to expand and
contract) have formed virtual waterfalls, and the water has also found its way
into many unplanned cracks in the structure. The deck of the Interchange (the
upper section that constitutes the bed of the roadway) is made up of eight feet
deep by eight feet wide, hollow "caissons." In some places as many as
seven caissons are found side by side. When finally inspected through newly cut
access-holes, some of these hollow caissons were found to contain significant amounts of standing salt water which had infiltrated the hollow structures. If you set
out to weaken a concrete structure, this is the easiest way to do it.
Cross section of part of the Turcot interchange
Over the years, many
efforts have been made to repair flaws in the Turcot Interchange. The built-in
lights were replaced by standard pole-mounted lights; the spalling concrete was
patched up over and over again. The caissons were drained and the roadways
above were repaired many times. But the expansion joints remained problematic and
the spalling of the structure became so pervasive in recent years that the
concrete was no longer patched; instead, in many places and for all to see, it was covered with two
layers of mesh (one coarse layer covering a fine one) to prevent lumps of spalled
concrete from falling onto people and cars passing underneath.
After the collapse of the de
la Concorde overpass in Laval a few years ago, worries about the structural
integrity of the spans brought about almost desperate measures. Anchors were
installed from the top of some of the caissons to the bottom, in the hope of
preventing structural disintegration and possible collapse of the caissons
(particularly the outer ones, and mostly at the expansion joints). The
Interchange is monitored 24 hours a day
now, at a cost of several million dollars a year; it is not uncommon to see
worksites set up where emergency structural repairs are quickly made.
Yet, I think the Turcot
Interchange should be fixed rather than torn down. Mine is a minority voice.
The engineering community has decided that tearing the structure down and
replacing it with a system of on-grade access ramps and a few overpasses will
solve "the problem" the same way the Pine-Park interchange problem
was solved. But a replacement operation will be complicated, costly, and damaging to the
environment.
As with a heart-lung
operation, the system has to be kept fully functioning while the replacement
operation takes place. The volume of concrete debris created would be huge, and
as many as 200 apartments would have to be demolished, which would squeeze the
last breath from the small enclaves left after the massive demolitions required by the initial construction. The free
space now existing underneath the overpasses will be cut up and made useless by
the earth embankments. (For a preview of what is planned, the Anjou
interchange is offered as a model.) Finally, the estimated cost of the whole
operation stands at 1.5 billion dollars. I am always wary of figures like 1.5
billion. Why not 1.6 or 1.4? Because nobody really knows what the final cost
will be! Look at the Notre Dame East reconstruction. Two years ago it was
estimated to cost 750 million dollars. Last month, without a spade having
touched the ground, the cost has gone up to 1.5 billion dollars. Need I also
point again to the sad saga of the Super-hospitals?
(Perhaps we ought to be concerned with ballooning costs
for highways eroding limited public funds, funds that ought to be directed at
mass transit infrastructure.)
There are two schools of
thought in construction: the conservative school (of which I am a member) and
the more radical slash-and-burn school. I use the word "conservative"
here as it was used during Apollo 13, the movie. When faced with possible
disaster, Apollo 13's mission control director Gene Kranz said,"What do we
got on the spacecraft that's good?" This attitude helped save the lives of
the astronauts. Taking a comparable
stance toward fixing the Turcot will surely save a lot of grief and an
incredible amount of money. Again, the "slash and burn" approach to
hospital renewal (now over ten years in limbo) comes to mind, and it is
interesting to see how reality has forced the McGill University Health Centre
to include a renovated Montreal General Hospital building in its original
tabula rasa plan. But I digress.
There are many precedents
for major infrastructure projects that have followed the conservative "modify
rather than demolish" route (see endnotes). An important one for all to
see is barely a mile away from Turcot and goes back over a century. The
original Victoria Tubular Bridge was built in 1859 in the form of a single
wrought iron tube on 24 ice-breaking piers. A single train track ran through
the tube. Towards the end of the century this arrangement was woefully
inadequate, and a new bridge was needed. By reusing the 24 piers, and using the
steel tube as a scaffold, the current truss-structure came into being.
According to the Montreal Herald of the time:
$6,813,000 for the original
1859 bridge, and $2,000,000 for the 1897 one. It seems that re-use certainly
paid this time!
In the link section at the
end of this chapter there are references to several other large infrastructure
repair and reuse examples.
Renovate the Turcot
My proposal for the
Interchange consists of three ideas.
One, public safety has to
be put first and foremost; a collapse like the de la Concorde overpass must at
all cost be prevented. The solution is to reinforce all or most of the spans of
the (until now) self-supporting concrete deck by deep steel beams. A triage should be done, to identify spans
that need extra support right now, those that can wait, and those that dont need reinforcement. (This process is common
in earthquake country: at a Tokyo train station viaduct I recently counted four
different structural reinforcement systems within five spans; the motto there
clearly was: repair if you can at all costs.) Fortunately installing supporting
beams is quite easy in most places because the Interchange is elevated above
grade as much as 100 feet, leaving ample room for a new, prefabricated
structural beam (or even an arch in the long span cases) to be inserted,
without obstructing passage below. Once the original spans have this additional
support, there is no longer any worry about structural collapse even if part of
the caisson structure has deteriorated.
It is important to note
that the de la Concorde collapse was due to an unusual "lip joint"
that was badly designed, badly executed, and not maintained for 40 years. The Turcot, on the other hand, is a
continuous, indeterminate structural system; this system has a lot of
redundancy in it, which, combined with an extra support system underneath will
guarantee ample structural strength for many years.
Model and section of repaired Turcot span (cross-bracing with
castellated beams not shown in the section for clarity)
Detail
of the existing concrete structure supported from below by a new grid of
man-high steel beams.
If added measures have to
be taken to bring the structure up-to-date for earthquake resistance, this is
the time to do it. In my references below I give links to many examples of
retro-fit earthquake proofing.
Two, the roadways on the
deck and the expansion joints will have to be redone. This process
should ensure excellent drainage is achieved to minimize water infiltration. In
addition, the minimum amount of salt and the maximum amount of harmless grit
should be used in winter from now on to keep the roads navigable. It is said
that it is impossible to have waterproof expansion joints, but every time I
drive over them on Rene Levesque in front of Place Ville Marie, I realize that
there is no water leakage in the underground city below. If it can be done
there it can be done at the Turcot. The spalled surface concrete now so evident
should also be repaired using the latest techniques.
Third, the maintenance of
the structure should rigorous and continuous. Following the practice of Gothic
Cathedrals (where maintenance structures were built into the fabric at the time
of construction), the new under-deck support structures that I suggest, would
serve as platforms for future maintenance of the concrete deck without the need
for expensive scaffolding every time a flaw becomes apparent. The steel girders
portrayed in the illustrations are of the castellated type, which feature large
openings in the web, allowing easy access by maintenance personnel.
It is my view that taken
together these three measures will allow the interchange to continue to
function for many years to come. During this time there will be opportunities
to improve and extend the public transit system with projects like the rapid
rail line to Trudeau airport, thus relieving some of the pressure on the
Interchange. Cars, on average, have become smaller and lighter since the Turcot
was built, so the rather tight dimensions of the roadways are actually becoming
less onerous as time passes.
Finally, one great
advantage of the methodology sketched above is that it can be completed in
steps, starting tomorrow. These steps can be small and we can learn from them
as we go along; costs can be tightly
controlled during a step-by-step repair of the system, and; no interruption of traffic and no displacement of people will be
required.
Counterproposal 2:
A case for the expansion of the Falaise St. Jacques into a linear
park.
The MTQs plans call for the realignment of the CN tracks and autoroute 20
close to the Falaise St. Jacques. Public pressure against this move has
recently led them to change their original plans: the location of the
right-of-way for the highway and the tracks are now set back from the Falaise by
15 meters rather than being right up against it. This change in alignment makes
the cost of relocation even more onerous when calculated as a charge per
hectare of land. My student group has focused their efforts on the design of
the expanded Parc Falaise St. Jacques.
One intriguing idea brought
up by them was that the Park could accommodate functions that are not available
in any of the other Montreal parks, such as horse riding, mountain biking and
orienteering. One student proposed in some detail a steel cable suspended from
a tower in Terry Fox Park, a small park at the top of the Falaise on St.
Jacques Street, that would allow visitors to slide down to a pavilion at the
bottom, across where rue Pullman now runs and where she had restored the St.
Pierre River. It was wonderful to see these ideas bubble up, and it reminded me
of the time in the early 70s, where, as students, my study mate and I proposed a green park
along the banks of the Lachine Canal (including a bike path) to incredulous
critics.
MTQ proposal to move
autoroute 20 and the CN tracks.
The new Parc Falaise St. Jacques which includes the Falaise proper
enlarged by a green strip (including Rue Pullman) and a bicycle/foot path along
the top of the Falaise.
Terry Fox Park, provides an
excellent location for the construction of an access pavilion towards the new Parc Falaise St. Jacques.
Section through the Falaise at Terry Fox Park, showing an entrance
pavilion straddling the drop in elevation toward the lower level. Design by McGill student Ali Nouri-Nekouri.
Section
through Falaise showing tower at left, sliding cable and Pavilion on artificial
mount across the St. Pierre river at the bottom of the hill. Design by McGill
student Emily Dovbniak.
People of Montreal! Get to know your Turcot Yards and Interchange!
Go visit and imagine what could be...
***
Getting to know the Turcot
Who has not heard: Traffic is heavy going in from the Turcot to
the Ville Marie this morning. or Coming from the West on the 20, avoid a stalled car in the right
lane heading onto the Turcot. or Smooth sailing through the Turcot this morning.
Everybody in Montreal knows
about the Turcot. Whether youre young or old, fit or not, a car driver or a bicyclist, French
or English, you can't avoid hearing the endless morning and evening traffic
reports that clutter Montreals airwaves. The nearly
300,000 cars that daily negotiate the many tentacles of the interchange
apparently form a large enough market to make this interminable Turcot traffic
intelligence broadcast-worthy round the clock.
But does everybody really
know the Turcot? Not really. In fact many people in Montreal know the lay of
the land in Old Orchard Beach or
Fort Lauderdale better than the in and outs of the Turcot Interchange and
Yards. And no wonder, because even today, with the property in Government hands,
anyone entering the domain is technically considered a trespasser. Before the site was acquired by the MTQ it
was railway property, tightly patrolled and strictly off-limits.
Yet the Turcot Interchange
and the Turcot Yards and the Falaise St. Jacques all belong to we taxpayers.
That is, to you and me, and whatever plans may be implemented by the MTQ will
in effect be financed by us. So, to better inform yourself, let me suggest that
you leave these words and take a trip to the Turcot Interchange to have a look
'round for yourself. After all, taking a peak at your own property can hardly
be seen as a real infraction. My nine architecture students and I made such a
trip in February through deep snow (and have been back several times) as part
of a Turcot-focused McGill
architecture design course. These trips have been a revelation. I provide links
to the blogs of several intrepid explorers who have paved the way over the last
few years, in my endnotes.
A walking tour of the Falaise St Jacques and the Turcot Yards
You can choose the high
road by starting from the Vendome Metro, or take the low from the St Henri
Metro, using the map composed here from Navigateur Urbain (a great online
resource that for free lets you combine photos and plans and allows you to
measure distances quite preciselya vital tool in judging a project this size!)
Let me give you some
tour-guide direction as you make a loop starting from on high at Vendome and
ending below at St Henri. Head west along de Maisonneuve and go left at Decarie
(dont miss the view at the still-vacant site of McGills Superhospital at your left, a silent
reminder of the way grand ideas get bogged down, their cost spiralling out of
sight.). Continue to the end of Decarie
Boulevard at St. Jacques, and turn left; cross the street to continue at the
South side of the street, which gives you a top-down view of the interchange,
always animated by streams of cars, rubies coming and diamonds going as the song says.
Continue over the massive
Decarie Expressway viaduct towards Girouard, (enjoy the view from here to the
South, over the Lachine Canal, all the way to the St. Lawrence and Mount
Johnson beyond) and keep going till you get to Terry Fox Park, a green strip shoehorned between St.
Jacques and the Falaise St. Jacques below to your left. Take the gravel path
that meanders down the middle of the park until youre about halfway through, where you will see
a hole in the fence (obviously well-used) separating the park from the
relatively steep slope below. (This is the location of the student-proposed
entrance pavilion shown above. From this pavilion you would be able to access a
belvedere and a set of stairs down the slope).
Slip through the hole, and
enter a strange green wonderland. In old photographs the Falaise appears as a
treeless dump, but in several campaigns dating back to the reigns of Jean
Drapeau and Jean Dorι, the site was gradually cleared of the most noxious detritus,
trees and bushes were planted, and it is now a green oasis rooted
between the rocky outcrops of stone and concrete fill that were left in place
after the clean-up.
Slip-slide down the first
part of the slope that is particularly steep, and enjoy a break at the level,
overgrown pathway used by intrepid NDG strollers and dog walkers. After your
break, continue down the slope till you reach the bottom. You have now
descended about 100 feet. Take care, because it is often wet down at the
bottom. Jump over the creek and get back to level, terra firma on the asphalt
of Pullman Road.
You can now see the green
Falaise from the bottom up, and, scanning counter-clockwise, you see the
three-kilometre extent of Rue Pullman stretch empty before you like a country
road. (In the student plans this road
would be turned into a meandering bike and pedestrian path that would run the
full length of the park. It would intertwine with the restored St. Pierre River.)
Keep on turning, and the
equally empty Turcot Yards stretch out in front of you as far as the eye can
see. Turn a bit more and auto route 20 comes into view in the South, about 400
meters away. (This view would be changed by my proposal for a landscaped berm
that would silence the traffic noise from auto route 20 and the CN tracks.)
Finally, turning some more,
the amazing outline of the Turcot Interchange appears. Curved, intertwining
concrete ribbons on high stilts form a strange, groaning monument of enormous
proportions. Its great height and the complete emptiness of the land below is
an important aspect of the Interchange because it allows the easy insertion of
support structures from below without compromising headroom, as I discussed above.
Now head East on Pullman
toward the interchange and pass underneath it to walk among the almost
100-foot-high portals created by the overpasses You cant help but notice the lower noise level down
here. The wonderful panels of graffiti adorning the massive piers of the
viaducts seem fitting here. You can imagine mature trees growing in this
amazing landscape, which we might call le forκt Turcot. A gate crosses the way from the Yards but
there is ample room to slip through.
Pullman ends at St. Remi.
Make a right turn there and duck underneath the beginning of the Ville Marie
expressway above. Go on a few feet until you get to rue Cazelais on your left.
In almost every window on the street an Action Turcot poster is on view, and understandably so,
because almost 200 housing units in this pleasant looking neighbourhood will be demolished if the MTQ plans are executed. This
community has been in the forefront of mobilizing scrutiny of the MTQ plans.
Rue Cazelais abuts Rue Desnoyers. Make a left there and a right when you get
back to Rue St. Jacques. St Henri Metro station is six blocks down the road.
You have made the Turcot loop! And you have seen great views from the top,
accomplished the descent the green Falaise, surveyed the vast empty Yards, marvelled
at the height and size of the Interchange, and walked by, maybe talked to, the
people of the threatened neighbourhoods.
In conclusion
It is important that we
Montrealers realize what is at stake here and also important that we realize
the now eerily empty Yards encompass an area more than twice the size of Old
Montreal. We should know that the Falaise could be a linear park almost four
kilometers long. Now a unique green area in the heart of the city, it could be
a recreational resource to rival sections of the Lachine Canal paths in
popularity. Finally, clearly understanding that the massive Intersection
structure is still doing the job it was designed to do a mere forty years ago, we must look seriously into upgrading it instead of simply
demolishing it.
The fate of this huge
"packet of urbanity" has been, lock stock and barrel, in the hands of
the Ministθre des transports du Quιbec, who have made, in isolation, major
decisions. In my view these decisions are misguided, and, at the very least
should be subjected to serious scrutiny. Adding some poetry and a good dose of
fiscal restraint to the review decision matrix would be a good start.
References
There are some interesting
blogs on the Turcot Interchange and Yards that are continuously upgraded. Andi
Rigas excellent blog has many links to other Turcot sites embedded in
it. See http://communities.canada.com/montrealgazette/blogs/metropolitannews/archive/2009/04/17/turcot-a-feature-in-four-blog-postings.aspx
Websites
Below some of the websites
that students and I created during the McGill 2009 winter term.
Some of the student work:
http://www.arch.mcgill.ca/prof/sijpkes/turcot_book/
The website below is a
short version of the original two-pronged alternative proposal to the MTQ plan:
http://www.arch.mcgill.ca/prof/sijpkes/Turcot/intro.html
The website below has many
chapters that look at other examples of re-use and repair of infra structure:
http://www.arch.mcgill.ca/prof/sijpkes/U2-winter-2008/presentation-turcot/cover.html
A particularly interesting
link is to the Victoria bridge project in Rochester GB, where an arch bridge is
turned into a truss bridge without interrupting traffic:
http://www.rbt.org.uk/bridges/oldgall.htm
The many twists and turns of Seattles decade-long Alaskan Way Viaduct saga can be traced on-line in posts too many to
list.