Toronto Ontario Line 3 | ?m | ?s | Metrolinx

fanoftoronto said:
Eglinton West LRT extension - The EPR Addendum is written solely to support the underground+elevated option that was championed by Doug Ford. The alternatives presented were non-sensical and made the underground+elevated option the preferred choice by default. The daily boarding for the current proposal is 5,000 riders lower than the surface LRT option, while being billions more expensive. How is that sound engineering design decision making?
Click to expand...
Amusingly, the city report on the same project did exactly the same thing, but proposed non-sensical underground/elevated designs to justify council's preferred option of running the LRT in the median. I'm not sure we've ever gotten a non-baised assessment of the design of that line.
 
Although not substantial construction, I find these updates interesting for what preliminary work/investigations are happening. A recent sample from this month (PDFs trimmed for space. Source.)

1660941513390.png

1660941537561.png

1660941822370.png
 
fanoftoronto said:
To be fair, I don't support SCC needing to be 25m below ground either. Scarborough has literally the widest streets in all of Toronto, which is ripe for either cut-and-cover shallow stations or elevation.

Also, this is a horrible argument: "they're doing it in other projects, why not here?"
A bad engineering decision is a bad engineering decision regardless of where it is being implemented.

With regards to Queen and Osgoode stations, I do understand why they'd rather go that deep than deal with the myriad of engineering challenges with a shallow tunnel, but it more seems like there is no proper decision making process.

How much more expensive is it to have shallow tunnels between University and Yonge streets vs the currently proposed deep tunnels?
How much time is saved by going shallow vs going deep and having the passengers traverse 4 sets of elevators/stairs to get between lines?

It would be super easy for Metrolinx to nix any naysayers by providing the cost-benefit analysis of shallow vs deep tunnels. If it's going to cost (just for an example) $5 billion extra to tunnel shallow, then it's a moot point to support shallow tunnels. But they don't provide any of their decision making processes and that makes me suspicious if they even do any proper cost-benefit analysis for the different options.
Click to expand...
The problem is that deep for the sake of being deep is becoming a bigger and bigger issue these days, especially in North America. Look at projects like Silicon Valley BART, Seattle's 2nd Subway, or NYC's SAS. These projects are built super deep with deep stations simply because politicians don't want their constituents to be '"negatively impacted by construction", which means minimal surface impact. All these projects could be built far shallower and far more convenient for general use. With the context in mind, it's also easy to assume that the same thing is being done with the Ontario Line, whether or not that's true only the engineers know.
 
^After the Crosstown experience, I defy anyone to prove that deep tunnelling prevents anyone from being “negatively impacted by construction”.

At the same time, we know that in our downtown, the OL tunnel cannot be shallow. It makes good sense not to disturb all the utilities and foundations that cut and cover would encounter. Excavating to the inevitable depth required would be expensive and hugely intrusive.

Plus, I’m guessing that as a percentage of overall project cost, the expense of the insertion and extraction shafts is large - such that the cost of an incremental mile or two of tunnel is attractive once the sunk costs (so to speak) of those two end shafts are assumed. And the end shafts have to be situated where most appropriate for the surface environment. However, there must be a tipping point where the added expense for deeper station shafts overtakes the cost of cut and cover where it is feasible. The entire project doesn’t have to be tbm’d just because part of the line must be tbm’ed.

- Paul
 
crs1026 said:
^After the Crosstown experience, I defy anyone to prove that deep tunnelling prevents anyone from being “negatively impacted by construction”.

At the same time, we know that in our downtown, the OL tunnel cannot be shallow. It makes good sense not to disturb all the utilities and foundations that cut and cover would encounter. Excavating to the inevitable depth required would be expensive and hugely intrusive.

Plus, I’m guessing that as a percentage of overall project cost, the expense of the insertion and extraction shafts is large - such that the cost of an incremental mile or two of tunnel is attractive once the sunk costs (so to speak) of those two end shafts are assumed. And the end shafts have to be situated where most appropriate for the surface environment. However, there must be a tipping point where the added expense for deeper station shafts overtakes the cost of cut and cover where it is feasible. The entire project doesn’t have to be tbm’d just because part of the line must be tbm’ed.

- Paul
Click to expand...
I don't think that anyone is realistically suggesting that cut-and-cover is the best way to build the downtown sections of the Ontario Line.

However, there is an argument to be made about tunnelling closer to the surface (but not as shallow as cut-and-cover), especially with the connections to the Yonge and University Lines. It seems penny-wise-yet-pound-foolish to build something for the sake of building it easier, rather than building it the utility for which it was originally envisioned. Building it shallower - which would involve Yonge-Eglinton-style construction for many years, it's true - would greatly improve the connections between the lines, which is one of the purposes for which the line was conceived.

Dan
 
AlvinofDiaspar said:
There are a few, but Covent Garden station is one. Used it before - not the greatest experience when I was, but it did the job. Not sure if the system is up to handling any serious rush hour crowds though.

AoD
Click to expand...
You can take the stairs at CG too, but most just queue for the lifts.
 
fanoftoronto said:
But that's the thing, what have the engineering firms done to earn my trust? Lets look at the currently ongoing public transit improvements in Toronto and my engineering gripes with them:
  • Eglinton West LRT extension - The EPR Addendum is written solely to support the underground+elevated option that was championed by Doug Ford. The alternatives presented were non-sensical and made the underground+elevated option the preferred choice by default. The daily boarding for the current proposal is 5,000 riders lower than the surface LRT option, while being billions more expensive. How is that sound engineering design decision making?
  • Eglinton West LRT extension - Arguably the widest ROW in all of Toronto, but only elevated for 1.3 km of the total 9.2 km length. Elevated is handily cheaper than tunneling. Granted the elevated portion is to get past the Humber River, which is logical. But why not elevate for the rest of Eglinton as well where there is tons of space to do so?
  • Scarborough extension - Again, wide ROWs, but deep stations with zero attempt to look at elevated. The station at Lawrence and McCowan is, I believe, one of the deepest in Toronto. This is to get below river in that area, but Metrolinx went elevated for the Eglinton West LRT, why are they tunneling deep in this location? They aren't even being consistent with their design decisions.
  • Yonge North extension - The distance between the end of the Bridge station and beginning of the High Tech station is around 300m. Stations are one of the most expensive parts of transit building in Toronto, they're building 2 stations within 500 m of each other in the outer fringe of the city. Where is the sound engineering decision making evident in this?
The above are only some of the reasons why I don't trust the city/Province's design decision making process. I don't doubt the skill of the engineers involved in these projects, just that they're decisions are made for them by politicians and others that don't know how to make design decisions. And the engineers are forced to manipulate the numbers to support these decisions.
Click to expand...

There is a good reason to have both the Bridge and High Tech stations on Yonge North; both will be placed entirely at the surface level in the same rail corridor, and will be a lot cheaper than a typical subway station.

And, a partial justification can be found for the underground Lawrence & McCowan station. An elevated line would conflict with the Hydro wires that cross McCowan just north of the Lawrence intersection. Although in that case, there is a feeling that they just didn't want to explore any alternatives. They could place a shallow underground station south of Lawrence, make the Lawrence lanes go on a low bridge over the emerging subway tunnel, and let the subway cross the creek on the bridge while remaining well under the wires. Or, perhaps re-route the Hydro corridor a bit.

Overall, I agree with most of your points. There is no reason to tunnel so much of the Eglinton West LRT. There is no need to place the STC station 25 m below the surface.

Yonge North rises questions, too. Metrolinx wanted to cut the cost by utilizing the Bala Sub rail corridor. But, that requires tunneling under the Royal Orchard area houses. Facing the public opposition, Metrolinx agreed to place the tunnel deeper than originally planned, and add a very expensive deep station at Royal Orchard. Taking into account the slightly greater total length, are we even saving anything compared to the original plan that had the line follow Yonge? But Metrolinx cannot back down now, their credibility is at stake.
 
beatle04 said:
DC actually has a subway station so deep that the only way to access it is via a high speed elevator. There are no escalators/stairs other than an emergency stair well. But to your point, that'd never happen here.
Click to expand...
Édouard-Montpetit Station on the Montreal REM will be deeper and will also not have stairs. (They have emergency stairs of course.)
 
Metrolinx keeps commenting about some architecturally breathtaking bridge across to Don River, and includes renderings of a rather plain arch bridge. Am I missing something? Is it going to a design competition? The bridges in the Portlands redevelopment are unique and striking. A white arch bridge had been done many times before.
 
EnviroTO said:
Metrolinx keeps commenting about some architecturally breathtaking bridge across to Don River, and includes renderings of a rather plain arch bridge. Am I missing something? Is it going to a design competition? The bridges in the Portlands redevelopment are unique and striking. A white arch bridge had been done many times before.
Click to expand...
the architecturally breathtaking bridge will be the south Don River crossing by the West Don Lands, not the north ravine crossing.
 
LemonCondo said:
Which one is this?
Click to expand...
This is the bridge I'm talking about. Could it be more utilitarian? Not much if you are building a single span bridge to cover that weight and distance. It is a basic arch bridge following a standard pattern that has had little thought put into it on how it fits into its surroundings and the East Harbour station. I wouldn't be surprised if they chose a single span bridge to avoid road interruptions, impacting the river flood protections, and potentially utilities, then someone looked at the single span bridge and thought it looked nice.

If they really wanted to do a stunning bridge they couldn't do it without considering what is already there and either decide to remove some of the industrial looking eyesores that are there or finding a way to hide them with design. I don't feel like an architect was involved here.

Image-1-1.png
 
Last edited:
You must log in or register to post here.

Back
Top