Danforth Line 2 Scarborough Subway Extension

[kEiThZ]

Reality check time

Add some stations, look for an optimized route (as they should have been doing), add an empty field, reduce the population and change name to Vaughan and off we go.

There are many reasons to dislike the SSE. But using Vaughan as a comparison is not one. It's only going to infuriate Scarborough residents. Vaughan has less density at VMC and isn't part of Toronto's tax base and isn't sharing operational costs. To suggest that Scarborough is the laggard in this comparison is offensive.

 

[TheTigerMaster]

Reality check time

Add some stations, look for an optimized route (as they should have been doing), add an empty field, reduce the population and change name to Vaughan and off we go.

Look for an optimized route? There's nothing optimized about the route of TYSSE, unless they were optimizing with the goal of wasting billions of taxpayers dollars. Tunnelling under empty fields. Sad!

 

[TheTigerMaster]

Reality check time

Add some stations, look for an optimized route (as they should have been doing), add an empty field, reduce the population and change name to Vaughan and off we go.

If we could build a six stop Subway extension in Scarborough for $3.2 Billion, I don't expect there'd be much opposition to that. I'd personally support that in a heartbeat.

 

[TheTigerMaster]

If it is indeed true, it makes sense. By having it deeper, you avoid sewers and other buried lines. You can also make it flatter.

There were utilities to avoid in the 1950s to 90s too. Doesn't really explain why subways today need to have such ridiculous depths.

 

[micheal_can]

There were utilities to avoid in the 1950s to 90s too. Doesn't really explain why subways today need to have such ridiculous depths.

There may have been problems that they are trying to avoid.

 

[Hopkins123]

It seems like each progressive phase of subway expansion in Toronto gets deeper. Any idea why?

NIMBYs are to blame.

Gone are the days when Toronto had the balls to cut-and-cover it's busiest transportation corridor (Yonge St) and leave it an open pit for five years in the heart of downtown. Now everything has to be TBM, even in deep suburbia, escalating costs to the point of public outrage even to suggest building a subway line.

 

[W. K. Lis]

It seems like each progressive phase of subway expansion in Toronto gets deeper. Any idea why?

Noise. The deeper the tunnels, the noise will be filtered better.

 

[kps]

NIMBYs are to blame.

Gone are the days when Toronto had the balls to cut-and-cover it's busiest transportation corridor (Yonge St) and leave it an open pit for five years in the heart of downtown. Now everything has to be TBM, even in deep suburbia, escalating costs to the point of public outrage even to suggest building a subway line.

Sure, if it weren't for that, an extension could just cut-and-cover along the former CNoR line, since it's in exactly the right place.

 

[denfromoakvillemilton]

This is it for me: Either build both subways, that being sheppard east and bloor danforth, or none at all.

 

[TheTigerMaster]

Noise. The deeper the tunnels, the noise will be filtered better.

And how much are we paying to save a few thousand homeowners from noise?

 

[W. K. Lis]

And how much are we paying to save a few thousand homeowners from noise?

Between the stations there are no difference. It's getting the stations down to meet the tunnels that is expensive.

 

[AlvinofDiaspar]

NIMBYs are to blame.
Gone are the days when Toronto had the balls to cut-and-cover it's busiest transportation corridor (Yonge St) and leave it an open pit for five years in the heart of downtown. Now everything has to be TBM, even in deep suburbia, escalating costs to the point of public outrage even to suggest building a subway line.

Actually gone are the days when the city actually expropriated en masse in downtown to build it (it being BD and early Yonge)

AoD

 

[OneCity]

https://www.thestar.com/opinion/letters_to_the_editors/2017/01/23/scarborough-choke-point.html

From the Stars hate mail bag.

Surely if a parking lot is required to be expanded they can build another level somewhere. Such an empty rant. But he did say boondoggle which met the main criteria to publish

Furthermore his concern sounds more like he thinks it will be a great success bringing in some new commuters of the 401.

 

[CapitalSeven]

A huge difference with the Yonge subway is that in two miles from Union to the Bloor there were 7 stations to build - close to a third of the distance. When you have that many stations in a shallow tunnel it makes sense to use cut and cover. The Scarborough extension is 4 miles of uninterrupted tunnel with a single station at the end in a parking lot. In that circumstance a bored tunnel makes logistical sense. And politically, you try tearing up the road in front of 4 miles of people, virtually none of whom will directly benefit from the extension.

 

[TheTigerMaster]

Between the stations there are no difference. It's getting the stations down to meet the tunnels that is expensive.

I'm no engineer, but I doubt that is true.

- Twice the depth means that the tunnel has to support twice as much dirt above it. That means more concrete and building materials to support the weight

- The deeper the tunnel, the harder it is for air to reach those depths. That means bigger, more expensive tunnel ventilation systems, to get air to these depths. These systems make up a non-negligible cost of subway construction. In comparison, Toronto's older subways are shallow enough that they can naturally ventilate, without specialized machinery.

- Deep tunnels increase the costs of emergency exits

- Temperaure control might be a concern so far underground. I recall that when the Russell Hill accident happened, the tunnel was dangerously hot for first responders, not because of fire, but because the tunnel trapped heat. Average tunnel temperatures increase significantly as depth increases, however the difference between seasonal absolute highest and absolute lowest temperatures decrease. Depending on exact conditions, tunnels 20 metres deep might require temperature control, so people down there don't fall ill due to high temperatures.