Dear Councillors McKelvie, Lai,
Karygiannis, Thompson, Ainslie and Crawford
Many of you support building the Sheppard
Subway and the Scarborough Subway Extension. So do we.
But none of us want to see huge parts of
our city destroyed by the TTC for 5, 6 or 7 years while they build stations
with their ‘cut and cover’ technique.
We want you to please move a motion at the
next TTC Board meeting.
Please ask Staff to report back on the
issues and opportunities raised in this letter.
This
is how the TTC builds stations
on a subway line.
Can you image this along Sheppard…
at Victoria
Park, at Warden, at Kennedy…
all at the same time…for 5, 6 or 7 years!
Is
there a better way?
Can
we get a subway system without destroying our communities and businesses?The answer is YES and experts in the TTC and their tunneling consultant Hatch know all about it.
Edward Poon of the TTC and experts from Hatch
went to the North American Tunneling Conference in Washington D.C. this past
June. They presented a paper advocating a better way to build subways. Their
conclusion:
While the cost of a large diameter running
tunnel between stations is higher
compared to twin tunnels, the savings in
the avoidance of cut and cover construction (stations
and track cross-overs) more than offsets the
larger tunnel cost in the running structure.
The estimated project cost saving at this
very preliminary stage was approximately 25%
of the capital
cost.
What
are they talking about? We call it the Barcelona Technique
because that’s who pioneered it.
The TTC has typically built our subways by
boring out two tunnels running parallel using tunnel boring machines [TBM’s] of
6 meters diameter. That’s how they built the recently opened Spadina-Vaughan
subway extension. For the Scarborough Subway Extension they are thinking about
using a single larger TBM of around 10.7 m diameter.
The single 10.7m TBM excavates maybe 60% more earth but saves the cost of building passageways between the twin tunnels for cross over tracks, service and emergency passages.
The Barcelona Technique takes this one step
further. It uses a 13m diameter TBM. That’s wide enough for trains to run side
by side, do all the cross over tracks and emergency passages they need AND… the key benefit…at stations, one
train can run on a deck above the other, as shown in the diagram below.
There
are three HUGE advantages
1.
No ‘cut and cover’ excavations at
stations = ZERO disruption to the street above;
3.
With a little forethought
future stations can be opened later if there is not sufficient demand today.
None
of this is possible with the TTC’s ‘cut and cover’ station building technique.
This
is a picture from Barcelona’s Line 9 under
construction. They are building the
deck within the tunnel so one train can run above the other. This will become a station when they’re done.
They can build major portions of the
stations while the TBM continues up ahead excavating the rest of the tunnel.
They can build major portions of the stations
while the TBM continues up ahead excavating the rest of the tunnel
How do people get down to these new
stations? You acquire a property next to the street
and excavate down and then laterally into the station. The shaft handles escalators/elevators,
emergency stairs, plus all the pipes and wires needed for the new station. ZERO
disruption to the street.
Picture on the right is how Barcelona did
it.
They are excavating the shaft down to track
level beside the street for the escalators, elevators and emergency
stairs.
Canadian tunneling companies are way out in
front of this industry: they just pioneered boring a diagonal shaft for
escalators down to the Moscow subway. Can we do that here?
What do other tunnel building experts
say about the Barcelona Technique?
Here’s what AECOM’s chief tunnel engineer
Verya Nasri says:
Both the time savings and
minimization of roadway right- of-way disruptions, due to cut-and-cover
construction, translate into significant construction cost savings and a more
manageable public relations effort.
Here’s what Michael Schatz, Managing
Director of Hatch says:
You get a better solution for
less cost.
Is any other city using the Barcelona Technique?
Yes. Just this past year alone, the cities
of Calgary and San Jose-Bay Area Rapid Transit systems researched everything
you could possibly know about subway building and chose the Barcelona Technique.
They did not want to tear up their downtowns for 5, 6 or 7 years.
What’s the catch? If TTC Engineers know
all about this why haven’t they told us?
It costs more to excavate a large diameter
tunnel. The savings come when you build stations.
It’s a clear winner for extending the
Sheppard Subway with perhaps 5 or 6t stations along the way to Scarborough Centre.
For the Scarborough Subway Extension, they
have knocked out all possible stations along the route.
Take away the stations and there can be no
savings! But no-one in the whole world has ever gone to the expense and
disruption of excavating a 6 kilometer subway tunnel…and built no stations
along the way! We will be the laughing stock of the world subway building
industry.
Serve the people of Scarborough: put the
stations back on this line at Lawrence and at Eglinton-Danforth. If someone
persuades you there is not enough demand at present for these stations, the
Barcelona Technique allows you to ‘rough’ them in. They can be opened later
with minimal disruption when demand warrants. You can’t do this with the TTC’s inflexible
cut and cover technique.
You need to hear from Edward Poon, Verya
Nasri, Michael Schatz, the people from Calgary, San Jose/BART, and Barcelona.
They believe the Barcelona Technique is the ‘better way’ to build subways.
Please put this letter on the agenda of the
next TTC Board meeting.
Please move a motion directing staff to
give you a full and fair comparison of the Barcelona Technique versus the TTC’s
typical ‘cut and cover’ way of building subways
Yours truly,
Lorne Ross for the Glen Andrew Community
Association.
CC: Luke Robertson, Chief of Staff, Office
of the Mayor.
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