Toronto Spadina Subway Extension Emergency Exits | ?m | 1s | TTC | IBI Group

M II A II R II K said:
How much faster and cheaper could this have been built if it all weren’t unnecessarily tunneled.
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Let's think about this practically.

TTC has a rule that no track should have more than a _% slope.

Assuming the York University station couldn't be located anywhere else, the track had to be _ m underground because it passes under some existing buildings. I guess York U could have chosen an elevated station but it would not be possible to locate it as close to the centre of campus as the choice location. Plus you would then need to find a way to transition from underground track at Old Downsview to elevated track in a completely developed area, save for the north end of Downsview Park, but then you'd be obstructing the clear path for landing aircraft.

Can anyone fill in the two blanks with accurate info?

The route crosses the CN railroad, the Hydro corridor, and the 407, none of which were willing to change elevations in any way, plus the Hydro corridor's pylons have presumably deep foundations so it's best to avoid tunneling under them and Hydro wasn't willing to relocate any pylons.

This was the gist of a TTC study I read more than a decade ago, which concluded tunneling was the only option. These last few years I have in vain searched for it online to help quell this recurring argument.

Basically, every time you try to engineer the route, there are 'way too many strikes against building at surface or elevated.

Flying at 30,000 feet, the real point you should be making is why couldn't they have planned for the subway well before all the other infrastructure and development was in place?
 
strookie said:
Let's think about this practically.

TTC has a rule that no track should have more than a _% slope.

Assuming the York University station couldn't be located anywhere else, the track had to be _ m underground because it passes under some existing buildings. I guess York U could have chosen an elevated station but it would not be possible to locate it as close to the centre of campus as the choice location. Plus you would then need to find a way to transition from underground track at Old Downsview to elevated track in a completely developed area, save for the north end of Downsview Park, but then you'd be obstructing the clear path for landing aircraft.

Can anyone fill in the two blanks with accurate info?

The route crosses the CN railroad, the Hydro corridor, and the 407, none of which were willing to change elevations in any way, plus the Hydro corridor's pylons have presumably deep foundations so it's best to avoid tunneling under them and Hydro wasn't willing to relocate any pylons.

This was the gist of a TTC study I read more than a decade ago, which concluded tunneling was the only option. These last few years I have in vain searched for it online to help quell this recurring argument.

Basically, every time you try to engineer the route, there are 'way too many strikes against building at surface or elevated.

Flying at 30,000 feet, the real point you should be making is why couldn't they have planned for the subway well before all the other infrastructure and development was in place?
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I feel like trenching at specific places while keeping it at tunnel level for other areas, like Rosedale > Eglinton was a perfectly doable option.

That way you can tunnel under all these obstacles and save money in the trenched areas where there are none, and the grade changes would be acceptable.

Until I see a paper outlining the numbers I will never believe that tunneling the whole thing up there was the best option. Sorry.

But I think the whole extension was unnecessary and influenced by Sorbara, who was an MP at the time and now, lo and behold, Sorbara Group is planning massive development along the line. Surprise, Surprise.
 
strookie said:
Can anyone fill in the two blanks with accurate info?
The route crosses the CN railroad, the Hydro corridor, and the 407, none of which were willing to change elevations in any way, plus the Hydro corridor's pylons have presumably deep foundations so it's best to avoid tunneling under them and Hydro wasn't willing to relocate any pylons.
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A few more blanks to know.
What is clearance of subway above Railway? This 1 is 7.2m, plus about 2.5m for the bridge superstructure (likely about span/18)
What is clearance below hydro lines (i.e. can it fit under hydro and above ground)?
What is clearance of subway above roadway? This 1 is 5.0m, plus about 2.5m for the bridge superstructure (likely about span/18)
 
robmausser said:
I feel like trenching at specific places while keeping it at tunnel level for other areas, like Rosedale > Eglinton was a perfectly doable option.

That way you can tunnel under all these obstacles and save money in the trenched areas where there are none, and the grade changes would be acceptable.
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Much of the DRL was planned to be in a Rosedale-style trench for this reason.

The next question to ask would be whether or not trenching is actually cheaper than boring with TBM. Trenching is still a very manual, and labour intensive process, while much of the work for tunneling is automated, so I can see why trenching might not have significant cost savings over boring (I’m not including station costs here).

On the other hand, I refuse to believe that a Rosedale-style trenched station costs anywhere near as much money as the Downsview-style mausoleum we just built.
 
TheTigerMaster said:
Much of the DRL was planned to be in a Rosedale-style trench for this reason.

The next question to ask would be whether or not trenching is actually cheaper than boring with TBM. Trenching is still a very manual, and labour intensive process, while much of the work for tunneling is automated, so I can see why trenching might not have significant cost savings over boring (I’m not including station costs here).

On the other hand, I refuse to believe that a Rosedale-style trenched station costs anywhere near as much money as the Downsview-style mausoleum we just built.
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True, although what SSE has shown us is that even with no stations (well, 1), the cost of ventilation and emergency exits also add to the TBM costs vs. trenching.
 
TheTigerMaster said:
On the other hand, I refuse to believe that a Rosedale-style trenched station costs anywhere near as much money as the Downsview-style mausoleum we just built.
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Perhaps but then everyone here would be complaining about our climate and how putting stations above ground is bad in the winter and so forth.
 
Edward Skira said:
Perhaps but then everyone here would be complaining about our climate and how putting stations above ground is bad in the winter and so forth.
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This kind of discussion needs to be stopped at all costs though. It would be like saying we should put all bus stops underground. Nothing that shelters and a good space heater system can't fix.

Or better yet, build the above ground stations with full height passenger screen doors and fully heat the platforms. Increase safety and shelter.

I don't see anyone complaining the UPX stations (at Union and Pearson) are cold and they are above ground.

Honestly the subway stations underground are COLD in the winter anyways. You are just out of the wind. Which again is what shelters are for.
 
This is all pointless discussion for a project whose EA was approved, I dunno, 10 years ago?

Probably we can all agree:
-Subways do not ALWAYS have to run underground
-It may be smart and save money to look at above-ground options where appropriate
-Possibly there are stretches of this project that could possibly have run above ground and maybe possibly saved some money in the process
-We don't know for certain that this is the case
-Next week we will find something else to complain about other than the subway's existence, Greg Sorbara, the overbuilt and/or underbuilt stations, suburban transit in general or at what altitude subways could and should run
 
What about an express tube under Lake Ontario? Why route a future relief line under Queen when you can go straight under Lake Ontario!
 
Rainforest said:
Does anything like that exist anywhere in the world?
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Not sure to tell you the truth but with some prefabricated tubing it is possible. You would need a submarine to secure it to the bottom of the lake. It would have the benefit of no stops for quite some time.. no emergency exits either
 
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