[W. K. Lis]

I like the elevated option across the flats at Jane because

a) It mitigates the grade problem
b) it avoids the traffic issues at the Jane intersection
c) It minimises impact on the recreational lands in the valley
c) It's a short logical and low-risk place to try some elevated construction in the city, to demonstrate the quality and cost-effectiveness of this method. If we don't try a little of things, we will have endless debates on a hypothetical level with most people not having direct experience with what is being discussed. A real life example is worth a thousand pictures.

As noted, tunneling under the river beds is an utter non-starter.

- Paul

Like how they handle rapid transit in Chicago?

 

[Tuscani01]

Like how they handle rapid transit in Chicago?

Why go to Chicago for inspiration? We have our own elevated guideway in Scarborough that is way less obstructive than Chicago's El.

Source: BlogTO

The connection between the Jane LRT and Eglinton LRT doesn't need to be right at the intersection.

 

[Palma]

reminds me of the Gardiner

 

[crs1026]

Does there need to be a connection at all ? Are we assuming Mount Dennis must be the maintenance base for a Jane LRT ? As opposed to Finch ?

It's downtown streetcar thinking to assume we need alternate routings.... Makes sense when you need to divert the 505 around a fire or parade .... But less meaningful for the extended LRT grid which won't have any alternate routes. Until we get a Jane LRT, the Finch and Eglinton lines will be landlocked anyways.

- Paul

 

[W. K. Lis]

History lesson. Hurricane Hazel flooded Eglinton Flats (Eglinton & Jane) in 1954.

The Eglinton Flats were originally garden lot farms, which were flooded out from Hurricane Hazel. Eglinton & Jane are now on hillocks above the floodplain. The land is currently saturated from the high water table because of the Humber River. Even rainfalls leave surface water that takes "forever" to drain. Going underground will have a BIG cost to it because of the high water table.

 

[crs1026]

This might be common sense but I was really wondering...

Why don't the lrt trains have third rails? Wouldn't it make sense for lrt trains to use a third rail whenever they are in a tunnel? One of the things that increases cost for lrt underground is the need to build in clearance for the catenary no?

Third rail is great for heavier rail that is used throughout the length of the line, but adding pickup shoes to LRT vehicles that will run above ground for long stretches is not that practical. There are platform clearance issues created, and the risk of electrical contact with pedestrians is not acceptable.

There are certainly systems out there that use third rail for above ground lines, but that's not ideal for Toronto. We don't need memorial shrines all along the Jane-Humber flats just because another raccoon has contacted the third rail.

- Paul

 

[rbt]

It seems to me it would make so much sense to have trains that would transition from catenary to third rail the second they entered a tunnel retracting the pantograph and significantly shrinking the size of tunnel needed, surely the engineers at Alstom or Bombardier could figure that out?

3rd rail has a number of issues (mostly smoke/fire and evacuation challenges). Overhead fixed rail (see Queens Quay and Spadina tunnel portions) is preferred by a number of Metros around the world for new tunnelled lines; even entirely underground heavy-rail ones.

Eglinton's tunnelling costs were not noticeably more expensive, as a %age of the overall project, than Spadina's (adjust for start year).

 

[dowlingm]

Mixed catenary and 3rd rail also means more weight for the pickup shoes which is another thing which will need maintenance. Also, with low floor cars shoehorning more stuff in at wheel level is another PITA.

 

[Edward Skira]

Getting closer.

 

[hawc]

Are the machines tunnelling towards each other? What happens when they meet?

 

[TheTigerMaster]

Mixed catenary and 3rd rail also means more weight for the pickup shoes which is another thing which will need maintenance. Also, with low floor cars shoehorning more stuff in at wheel level is another PITA.

From what I've heard, 3rd rail adds a non negligible amount of friction.

 

[cplchanb]

Are the machines tunnelling towards each other? What happens when they meet?

I think I remember reading before that they might bury 1 set and extract the other....or was that for something else............

 

[TheTigerMaster]

Are the machines tunnelling towards each other? What happens when they meet?

They keep drilling into each other until one tears the other apart. The winner is declared strongest TBM in Toronto, and goes on to global championship round.


But seriously, the TBMs coming from the west will reach the extraction point at Yonge before the TBMs from the east.

 

[marcus_a_j]

They keep drilling into each other until one tears the other apart. The winner is declared strongest TBM in Toronto, and goes on to global championship round.

The next generation of robot wars.

 

[crs1026]

I think I remember reading before that they might bury 1 set and extract the other....or was that for something else............

Both sets will have to be removed in order for track to be laid through the extraction area.

- Paul