[gweed123]

Yes exactly. I don't know I suppose it depends on the dwell time differences between using Union as a terminal station vs through station. Combined with use of Summerhill station (the great rail hype of regional transit in the GTA) could that not relieve pressure off of Union by up to, say, 25%?

I really don't know what the difference would be, and whether that difference would be enough to eliminate the capacity crunch. In all of my maps though, the only line that uses Union as a terminus is the Milton line (it's the odd man out, so to speak).

As for Summerhill, it would certainly be of value to a Midtown GO line, but I don't think it would be a good idea to pour too many people into there, because of the Yonge capacity crunch. The only way I would put a lot of pressure on Summerhill is if it became the terminus of a Bay St subway (aka a Yonge Express line). But that's a pipe dream for sure.

For what it's worth, here's the quick map I did of what I'm talking about:

 

[Thernan]

Personally, I would like to see two downtown relief lines.

One that travels from Main station southward through the Beaches and along Queen (to replace teh streetcar) that would eventually continue on Lakeshore all the way to Long Branch and then go northward to Sherway Gardens (to which teh Bloor line could also be extended). This would do a great deal to improve transit access to the poor buggers living in places like Grenadier Point, Parkdale, Mimico etc...who currently have few decent options.

The second one would begin at Jane, head southeastward to connect to the western downtown, Exhibition place, Island Airport, Union Station, Docklands and then northward through Leslieville to eventually reach Pape.

We should also seriously think about having a second subway directly beneath the yellow line to double its capacity.

 

[gweed123]

I think that would depend on geological conditions. Toronto hasn't had a single bore tunnel in... decades? If Crosstown is twin bore not sure why a Queen-Crosstown wouldn't be.

Anyways, the same relative cost increase would apply. Whether the cross section looked like (F)-(F)-(S)-(S) or (FF)-(SS) it would still require twice the tunneling of a single technology system (F)-(F) or (FF). F being fast tracks and S being slow tracks. In other words, if you could fit two tracks in one tunnel, then you'd still be doubling the amount of tunneling from one to two by running an LRT beside a GO tunnel.

I'm not sure what the geological practicality of such a plan would be, I'm just presenting an alternative, much like what Metrolinx did with the capacity study last year.

As for the tunnels, I would have them arranged like this: (FS)(SF). I'm not sure why Metrolinx went with 2 tunnels of Eglinton instead of one large one. It could be that it's simpler construction to do two smaller tunnels, even if you require twice the amount of TBMs.

 

[rbt]

I'm not sure why Metrolinx went with 2 tunnels of Eglinton instead of one large one.

http://stevemunro.ca/?p=2372

"In a conversation after the meeting, I learned that although the single large bore tunnel (13m) proposed for Eglinton might be feasible, this large tunnel greatly increases the cost of removing spoil (earth and rock) because the tunnel structure is much larger than would be the case for two single tunnels. In turn, this begs the question of how much of the Eglinton line will be built cut-and-cover so that it is not dependent on the availability of tunnel boring equipment. We shall see in the fall when the next set of community meetings come around for the Eglinton corridor study."

In short, dirt disposal is a non-trivial cost.


I also recall a TTC report in 2010 or early 2011 indicating a single tunnel might not fit between building foundations without reinforcement of the buildings. The tunnel itself would fit, obviously, but a buffer for stability is required around the tunnel and that buffer increases with the size of the bore and instability of the soil. I cannot find this report.

 

[Jaye101]

We should also seriously think about having a second subway directly beneath the yellow line to double its capacity.

I think I'd rather a line parallel to Yonge than one directly underneath. One that runs from Bloor-Yonge, veers east to Church, heads south, then west to Union at Front staying on that angle from Church and to Southcore and eventually up Spadina to Bloor once the University line is overcapacity (after the drl is built, of course)

I believe we need two new east-west subway lines between Front and Bloor in order for the core to expand at it's full potential within the next 30 years. Even if the second is a short line from the Don to Roncesvalles.

 

[gweed123]

http://stevemunro.ca/?p=2372

"In a conversation after the meeting, I learned that although the single large bore tunnel (13m) proposed for Eglinton might be feasible, this large tunnel greatly increases the cost of removing spoil (earth and rock) because the tunnel structure is much larger than would be the case for two single tunnels. In turn, this begs the question of how much of the Eglinton line will be built cut-and-cover so that it is not dependent on the availability of tunnel boring equipment. We shall see in the fall when the next set of community meetings come around for the Eglinton corridor study."

In short, dirt disposal is a non-trivial cost.


I also recall a TTC report in 2010 or early 2011 indicating a single tunnel might not fit between building foundations without reinforcement of the buildings. The tunnel itself would fit, obviously, but a buffer for stability is required around the tunnel and that buffer increases with the size of the bore and instability of the soil. I cannot find this report.

Interesting, thanks for that.

I remember a couple years ago there was a discussion about building a fill island in the Humber Bay, in order to shield the beach from the polluted water coming down the Humber. If one of the tunnel launch shafts is around Roncesvalles and Queen, it wouldn't be nearly as long of a trip to dump fill as it would be from Eglinton.

Logistically, this wouldn't be all that dissimilar from what Montreal did to build Ile Notre Dame for Expo. So that would potentially solve the fill problem.

The foundation problem is an interesting one. I wonder if building them as stacked tunnels (LRT on top, GO on the bottom) would solve that problem.

 

[ssiguy2]

Just sort of an off question............what exactly are they going to do with all the dirt?

I know some cities use it to create islands like Montreal so what does Toronto have in mind?

 

[bleu]

^ fill in the gap between the city and YTZ. saving the cost of making that tunnel (and the stupid 30 seconds ferry ride).

 

[W. K. Lis]

Just sort of an off question............what exactly are they going to do with all the dirt?

I know some cities use it to create islands like Montreal so what does Toronto have in mind?

MGM would need some dirt to build their casino project.

 

[gweed123]

Just sort of an off question............what exactly are they going to do with all the dirt?

I know some cities use it to create islands like Montreal so what does Toronto have in mind?

Are you referring to Eglinton? Or the future subway project that we're discussing here?

 

[Woodbridge_Heights]

I wouldn't mind them adding to the Leslie spit and/or doing a similar thing out at Humber Bay park.

 

[gweed123]

I wouldn't mind them adding to the Leslie spit and/or doing a similar thing out at Humber Bay park.

I'd rather see the Humber Bay personally. It would be really nice to have a meandering park out there. Would make for some pretty nice green space. Plus the area between the spit and the mainland could become a pretty nice beach area. I always feel like the Humber Bay area is squeezed between the Gardiner and the lake. Having some extra land to walk out to out there may make it feel more wide open. Plus the view of downtown would be spectacular.

 

[TheTigerMaster]

Just sort of an off question............what exactly are they going to do with all the dirt?

I know some cities use it to create islands like Montreal so what does Toronto have in mind?

For Eglinton last I heard they were looking in to creating three islands off the shores of Humber Bay.

 

[drum118]

Madrid and other systems in Europe are built as a one tunnel to handle 2-4 tracks. There are some lines that have twin tunnels.

It has been stated our tunnels have to be twin for safety reasons. Unless there are a lot of fire doors between these tunnels, waste of time and money.

Look at the tunnel NYC is building for its new lines and that is one hell of a hole in solid rock.

 

[rbt]

Look at the tunnel NYC is building for its new lines and that is one hell of a hole in solid rock.

It's 3 billion per mile or something like that for the East Side Access project. It should buy one heck of a large hole.