Thursday, September 29, 2016

Part One: Introduction

Scarborough Subway Project
Part One: Introduction.

We are all in favour of getting subway service to our Centre. We’re just not sure the City-TTC have figured out the best way to do it. The plan they put in front of Toronto Council in June is only 5% completed. It’s like an approval in principle.

They were directed by Council to proceed with further design work and costing for their preferred route ‘and other possible alignment options’.

We believe their preferred alignment will have horrendous consequences for the Glen Andrew and North Bendale communities during the 5 or 6 years of construction.

We have put two ‘other possible alignments’ in front of the City-TTC staff. Both have been rejected quickly. As far as we can tell, they are only studying their own proposal.

We believe our community, and our elected representatives Glenn DeBaeremaeker, Brad Duguid and Salma Zahid who will be asked to approve and/or fund this subway, deserve better answers from the TTC-City Planning.

To help you catch up to what we have been doing and form your own opinions, we’ve put together four pretty short documents to tell you what’s going on.

Part 1: What do you need to build a Subway extension to Scarborough Centre.
Part 2: The TTC-City Planning Proposal
Part 3: You Have to Be Kidding, Right? Our critique of the city’s proposal
Part 4: Our Proposals. Alternate Alignments for the Subway Extension.

It’s your home. It’s probably your biggest investment. It’s your community. Read the posts in this blog. Get involved. Tell us what you think is best for our community.
Contact Glenn DeBaeremaeker at:
Contact Brad Duguid at:
Contact Salma Zahid at:
Contact City Planning at :
Lorne Ross for the Glen Andrew Community Association.

What You Need to Build A Subway
In the course of meeting with TTC-City Planning Staff they have helped us understand what is required to build a subway extension to Scarborough Centre.
Here’s what we’ve learned so far.

First: The Launch Shaft.
To get the Tunnel Boring Machine [the TBM] started on its way you first have to excavate a humungous hole, called the TBM launch shaft, at the very start of the track. It’s got to be large enough to lower the huge TBM all the way down to the future track level.

This photo is from the TTC’s Spadina- Vaughan subway extension. That white barrel shaped thing is the cutting head of the tunnel boring machine [TBM] Holey at the bottom of the launch shaft.

This photo a TBM cutting head being lowered down one of the launch shafts for the London England Crossrail subway project.
Both of the TBM’s in these photos are about 6 meters in diameter. The TTC is thinking about using a TBM of over 10 meters in diameter.

Second: Initial Tunnel Boring, The Tail Track.
The TBM launch shaft is located about 300m from the first [and in our case the only] station on the line. The TBM digs its way forward and right through what will be the station location and carries right on digging the tunnel. At this point in the process, all of the clay, rock sand it excavates is conveyed back to the launch shaft and lifted to the surface to be hauled away by dump trucks. Plus all the materials needed to build this part of the tunnel are brought to the launch shaft, lowered down to track level and moved forward as the TBM progresses.
The 300 m tunnel from the launch site to the first/only station will become the ‘tail track’ for the subway. It’s a safety feature in case a train ever approaches the station and the brakes fail.

Third: The Station.
The first and only station proposed by TTC-City Planning is not just a subway station: there are +\-14 TTC bus routes coming into Scarborough Centre Station today, plus several GO bus routes, plus long distance Greyhound and Megabus routes serving places as far away as Montreal, plus buses going to places like Casino Rama. All of these have to be moved over to the proposed new station in the east mall parking lot.

Fourth: The Work Site.
It takes years to build a subway station/bus terminal. If you are going to get an early start on building the station, you cannot have 500,000 cubic meters of clay, rock and sand excavated by the TBM as it
works its way down to Kennedy Station passing back up the tunnel and through the very place where you are trying to build the station. You can’t have thousands of truck loads of precast tunnel liners needed to build the bare tunnel passing the other way through where you want to build the station. If you did that, you would have to wait until the whole tunnel was built before you start work on the station. To work on the station while the TBM builds the whole length of the tunnel, you need what is called the “Work Site” and it has to be located further down the line past the station.
The work site is another huge hole excavated down to track level. It replaces the launch shaft as the place where all the excavated clay, rock, sand whatever is lifted to the surface on conveyors, dumped into heavy trucks and hauled away. Everything you need to build first the bare tunnel and then to build the actual subway track is brought to the work site by flatbed and other heavy trucks and lowered down to track level at the work site.
It is a super busy place generating a massive volume of heavy truck traffic. And it will operate for 5 or six years. It operates 7 days a week.
Once you have the work site operating, you no longer need the launch shaft. It can be filled in and the site restored. Maybe an emergency escape and air vents for the subway would remain on the launch site after it is restored.
Once you have the work site in operation, you can start building the subway station while the TBM continues boring its way 6 kilometers down to Eglinton.
Below is a photo of a typical work site:

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