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Danforth Line 2 Scarborough Subway Extension

nfitz said:
I was hesitant to link it as we've discussed the drawings before, and it's a 150 MB file.

It's the "Environmental Project Report - Volume 1" on the TTC's website for the Line 2 Extension - https://www.ttc.ca/About_the_TTC/Projects/Scarborough_Subway_P
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Thanks.
  1. Starting from Eglinton - the tail tracks (underside of tunnel) are 10.5m below grade.
  2. Because of tunneling, this quickly increases to 23m by Midland.
  3. This make a Brlimley station 24m deep. Presumarbly, with cut-and-cover, this could be ~10 to 12m deep. What would that be, half the cost? The station would have to be entirely west of Brimley.
  4. Keep in mind that each emergency exit would also be half the cost due to depth.
  5. At Lawrence/McCowan, the TBM option is 35m below grade.
  6. I actually like the West side alignment, since it disrupts traffic less during construction. Basically, I would say the top of tunnel would be a flat at Elevation 155m, or sloping up a bit northwards to 156.5m (maybe 0.5% slope). With a 6.0m superstructure, this puts the soffit at about 149m - or 1.3m clearance (maybe 1.8m at stream centre-line). It looks like the service entrance to the hospital could be used for temporary access. the more I look at this, the more doable it looks.
  7. For horizontal alignment, my first beef would be at Ellesmere. I would try to start the curve to the west a little bit farther north (maybe 200m) to spare those few houses.
  8. Nobody will mind chopping a 15m wide swath through that small wooded area, so cut-and-cover is still working here. It also adds a nice connection from Borough Dr. to McCowan/Ellesmere corner.
  9. The TBM launch site is in the right location, but it should drive north to the CPR rail yard (just north of McCowan/Sheppard). It may also be used to drive south towards Lawrence (Highland Creek) if needed.
 
BurlOak said:
Thanks
  1. This make a Brlimley station 24m deep. Presumarbly, with cut-and-cover, this could be ~10 to 12m deep. What would that be, half the cost? The station would have to be entirely west of Brimley.
  2. Keep in mind that each emergency exit would also be half the cost due to depth.
Click to expand...
Where do you get this idea that cutting the depth in 1/2, assuming that were feasible, would reduce construction cost by 1/2? I can assure you it does not work that way.

The typical cost of constructing subway At-Grade is 65% or so of the cost of tunneled. So you sure as hell are not getting a still tunneled project down in cost by 1/2!

There are many sources for this, but here's one: http://lrt.daxack.ca/LRTvsHRT/CostCompare.html

When one gets into the nitty gritty of cut and cover vs tunneling, its simply not right to assume that you would cut material down for instance, when cut and cover tunnels will typically be physically larger, and you need to shore all the way down to working depth.

There is typically more disruption and therefore time-delay involved with cut and cover, and time is money; and land acquisition costs are higher.

Your assumptions are completely off-base. Sigh.
 
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W. K. Lis said:
If the 504 KING streetcar has a ridership of 84,000 over its mixed-traffic length, a light rail line over a private right-of-way should have more. No!! MUST be heavy rail subway.
o_Oo_Oo_O
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The goal of the subway is to reduce the otherwise insane number of transfers many Scarborough residents are facing. Bus to SRT/SLRT, then RT to subway, then perhaps subway to another subway, and then to another bus or streetcar.

Looking at capacity only, a light rail line could do the job.
 
OneCity said:
I also love the addition of a Brimley/Danforth area stop and don't see the chaos of starting over worth the long term savings on Lawrence. Its time to fix the design for the missing stops and move forward.
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The question is whether the tunnel design has to change in order to restore the Lawrence station. If the changes are substantial (need to go deeper, need to add room for a crossover, change the curvature etc) then it might be essentially a new tunnel design, just on the same route as before. If so, then the design duration for a new tunnel under Brimley will be same as under McCowan. Btw, this proposal would not move the STC and Sheppard stations. The Lawrence station would be at Brimley, but somewhere north of Lawrence, the line would veer east a bit, and arrive to the already-confirmed STC station location.

On the other hand, if the Lawrence station is compatible with the current tunnel design (just construct the tunnel and then excavate the station box), then indeed it might be best to keep the changes to a minimum and proceed with the current route.
 
Rainforest said:
The question is whether the tunnel design has to change in order to restore the Lawrence station. If the changes are substantial (need to go deeper, need to add room for a crossover, change the curvature etc) then it might be essentially a new tunnel design, just on the same route as before. If so, then the design duration for a new tunnel under Brimley will be same as under McCowan. Btw, this proposal would not move the STC and Sheppard stations. The Lawrence station would be at Brimley, but somewhere north of Lawrence, the line would veer east a bit, and arrive to the already-confirmed STC station location.

On the other hand, if the Lawrence station is compatible with the current tunnel design (just construct the tunnel and then excavate the station box), then indeed it might be best to keep the changes to a minimum and proceed with the current route.
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  • In plan, the line start a slight horizontal curve about 185m south of Lawrence. Since the station will be entirely north of this point - no change is required for this.
  • In terms of vertical, again the station box would be north of the river, so it should be ok, unless there is some very porous soil that might make de-watering difficult.

I look to the Ontario Line where they (Metrolinx) did everything possible to make the line as shallow as possible. There is was not related to the actual crossing of the Don (tunnel under vs. bridge), but to save costs of the very deep stations on either side of the river (Sumach and East Harboour). Pretty much the same scenario as here (if a Lawrence Station is being added). I look to Vancouver, where they took a political hit to allow the Canada Line to be built cut-and-cover - because they knew it would save good chunks of money.
  • I would be shocked if they don't bridge over Highland Creek.
  • I am almost sure they will TBM from STC north to Sheppard (I hope they go to the Agincourt CPR yard).
  • I suspect they will TBM from STC south to Highland Creek (seems to be enough space there just north of the creek for extraction).
  • If they add the Brimley station, I think they will use cut-and-cover, but they will TBM if not. This may depend on whether they want to be seen as "fair" in using cut-and-cover here and for the Ontario Line, or for neither.
 
cplchanb said:
regardless of whether they actually withheld info or not, Matlow is being an asshole by bringing this up at the critical juncture and potentially fuelling another generation of decisive debates.
just get the thing designed and built already for gods sake!!!!!
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What critical juncture? The provincial government just passed legislation forcing the city to stop all work, and have deferred the planned 2026 opening by years, while they revisit the design.

This is all in the province's hands now. Councillors have every right to call out the lies told to them, and hold people accountable.
 
nfitz said:
What critical juncture? The provincial government just passed legislation forcing the city to stop all work, and have deferred the planned 2026 opening by years, while they revisit the design.

This is all in the province's hands now. Councillors have every right to call out the lies told to them, and hold people accountable.
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This revelation is going to drag into the next election, and frankly, id bet that the conclusion wouldve been the same even with this secret info. Matlow is one of the few still trying to scrape the bottom of the barrel on this issue, but i guess they dont really care anyways since in the end they will still get their posh pension either way.
 
cplchanb said:
regardless of whether they actually withheld info or not, Matlow is being an asshole by bringing this up at the critical juncture and potentially fuelling another generation of decisive debates.
just get the thing designed and built already for gods sake!!!!!
Click to expand...

It's not Matlow, it's The Star, which has been able to evaluate what actually happened due to the Freedom of Information Act.

I don't think anyone can accuse Matlow of not being very clear in his opposition to this project.
 
cplchanb said:
This revelation is going to drag into the next election, and frankly, id bet that the conclusion wouldve been the same even with this secret info. Matlow is one of the few still trying to scrape the bottom of the barrel on this issue, but i guess they dont really care anyways since in the end they will still get their posh pension either way.
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Maybe instead of being angry at Matlow, you should be angry at Tory and friends for doing this in the first place?
 
syn said:
Maybe instead of being angry at Matlow, you should be angry at Tory and friends for doing this in the first place?
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Thats what democracy is isnt it? Majority rules? I'm angry at every politician like mamolliti and matlow who in their stubborn and selfish ambitions to make themselves look good continuously revisit decided matters over and over again. This is the reason why things never get built here. Is it worth sacrificing a generation just so you can fight for a slightly different alignment or mode of transport? I dont care if in the end theres a slight advantage to LRT
but to hold up construction and suffer endless price increases and delays due to infighting is criminal in itself. Remember we pay for their council mosh pits too. He needs to realise when there
is no point in resisting a losing cause.
 
cplchanb said:
This revelation is going to drag into the next election, and frankly, id bet that the conclusion wouldve been the same even with this secret info. Matlow is one of the few still trying to scrape the bottom of the barrel on this issue, but i guess they dont really care anyways since in the end they will still get their posh pension either way.
Click to expand...
Why are you blaming Matlow for this? The Star made the FOI request at the time, and JUST got the results back. Matlow hasn't pushed the issue in council.

Clearly, Metrolinx was trying to bury this. Why do you defend such lies and cover-ups?

The only reason this will drag to the next election, is Doug Ford and the Conservatives have delayed the project. They were fully-funded, ready to start tendering, with construction starting before the election. Doug Ford personally made sure this couldn't happen.

Doug Ford and his brown-nosed minions have delayed this. Not Matlow.
 
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