[andrewpmk]

The detailed design of the Don Mills station and adjacent line segments is not available yet. They might be able to keep the tail track (east of Don Mills) underground, while the two main revenue tracks ascend to the surface level before the Ferrand stop.

Given that the Eglinton line is designed for 90-m trains at most, they will need something like 120 m of extra tunnel; or even less if the western half of tail track is located in the section that will be tunneled anyway.

Why would you want to have such a complex design like that, rather than just eliminating the rather useless Ferrand stop? Plus if the downtown relief line goes to Don Mills/Eglinton, you need provision for that in the design, which makes the design of the station even more complicated.

 

[Platform 27]

I am not sure, but I think the decision to use TBM was before they realized that boring could not be done under the existing subway lines. Essentially, these are 3 separate boring jobs each about 3 km long (the East one is a bit longer now that the launch site was moved to Don Mills). In those 3 kilometres, there are 3 or 4 stations (each with probably about a 200m cut excavation), plus a launch and extraction site. This means that even though TBM is used, about 1/3 of the total length is actually built with cut-and-cover. (If the station spacing on the DRL are closer, this could become over half).

Eglinton's tunnels are considerably deeper on average than most other lines on the subway (look at the stairs on Caledonia station's secondary entrance for one example of how this line has shades of the London Tube). I don't think there was much of an opportunity to go shallower because train climbing grades can't keep up with the hilliness of Eglinton itself. Even if the community disruption issue was a non-factor (and we know it very much isn't), I'm willing to guess the depth of the trench that would need to be excavated probably wipes out any cost-savings of a bore.

 

[BurlOak]

Eglinton's tunnels are considerably deeper on average than most other lines on the subway (look at the stairs on Caledonia station's secondary entrance for one example of how this line has shades of the London Tube). I don't think there was much of an opportunity to go shallower because train climbing grades can't keep up with the hilliness of Eglinton itself. Even if the community disruption issue was a non-factor (and we know it very much isn't), I'm willing to guess the depth of the trench that would need to be excavated probably wipes out any cost-savings of a bore.

I thought LRT can handle a 5% slope. I would guess that the grade on Eglinton is never more than 5% - it is shown as 4.9% for the hill just east of Brentcliffe. The LRT (or Skytrain, but not HRT subway) could probably have just followed the road profile - about 8 to 10m down. Maybe they just wanted to smooth out the line for passenger comfort - but then the latest revision to go under the Don River West Branch adds extra undulation.

 

[junctionist]

I thought LRT can handle a 5% slope. I would guess that the grade on Eglinton is never more than 5% - it is shown as 4.9% for the hill just east of Brentcliffe. The LRT (or Skytrain, but not HRT subway) could probably have just followed the road profile - about 8 to 10m down. Maybe they just wanted to smooth out the line for passenger comfort - but then the latest revision to go under the Don River West Branch adds extra undulation.

Subway technology can handle grades of more than 5 percent, but it has to be rubber tired. The Montreal Metro trains can handle grades of 6 percent according to John Martins-Manteiga in his book Metro: Design in Motion.

 

[Monarch Butterfly]

I thought LRT can handle a 5% slope. I would guess that the grade on Eglinton is never more than 5% - it is shown as 4.9% for the hill just east of Brentcliffe. The LRT (or Skytrain, but not HRT subway) could probably have just followed the road profile - about 8 to 10m down. Maybe they just wanted to smooth out the line for passenger comfort - but then the latest revision to go under the Don River West Branch adds extra undulation.

There are hills on Eglinton that are over 5%, which is the limit for the light rail vehicles. The streetcars are supposed to be able to handle 8% inclines, but not the light rail vehicles for the Transit City lines. From Keele east to Caledonia, the tunnel inclines will have to be no more than 5%, which is why the station at Caledonia is very deep, but the station at Keele is shallow, the tunnels cannot exceed 5% incline.

 

[Rainforest]

Why would you want to have such a complex design like that, rather than just eliminating the rather useless Ferrand stop? Plus if the downtown relief line goes to Don Mills/Eglinton, you need provision for that in the design, which makes the design of the station even more complicated.

I don't think it is very complex, to extend the tunnel by 60 m or even 120 m.

Downtown relief line station will be close to Don Mills and rather far from Ferrand, so yes it will add complecity, but totally unrelated to the design of the eastern tail.

Ferrand stop will help riders walking from the residential area, located south of Eglinton and just west from DVP.

 

[dowlingm]

They should have done cut and cover! This is ridiculous. Cut and Cover would have save 5 years and maybe this is up and running in 2018! Same with the DRL. Hell cut and cover would all us to do all the Transit projects faster.

Pardon me for judging you based on your username, but maybe you could do a Street View trip through Eglinton say from the Allen to Bayview and then imagine how a cut/cover would go. The property owners along there won't be caught napping like the ones on Vancouver's Cambie Street were. The reference to subway performance at high grades is interesting, since there was a big deal made about these tunnels being able to be retrofitted for subway by which I think most people thought steel-on-steel.

 

[innsertnamehere]

Dan actually lives in minniopolis, so it is understandable that he doesn't know the area that well.

 

[denfromoakvillemilton]

Pardon me for judging you based on your username, but maybe you could do a Street View trip through Eglinton say from the Allen to Bayview and then imagine how a cut/cover would go. The property owners along there won't be caught napping like the ones on Vancouver's Cambie Street were. The reference to subway performance at high grades is interesting, since there was a big deal made about these tunnels being able to be retrofitted for subway by which I think most people thought steel-on-steel.

I live in the city, but I hear your responses. I agree now. I guess I was wrong.

 

[ssiguy2]

I'm the one that lives in suburban Rainforestcity and am a stauch critic of the obscene waste of funds resulting from the Eglinton/SRT combo, perhaps you were think of me?

 

[JayBeeGooner]

There are hills on Eglinton that are over 5%, which is the limit for the light rail vehicles. The streetcars are supposed to be able to handle 8% inclines, but not the light rail vehicles for the Transit City lines. From Keele east to Caledonia, the tunnel inclines will have to be no more than 5%, which is why the station at Caledonia is very deep, but the station at Keele is shallow, the tunnels cannot exceed 5% incline.

Aren't inclines limited to 5% due to passenger safety and comfort? I am sure LRV's can climb greater than 5%.

 

[smallspy]

Aren't inclines limited to 5% due to passenger safety and comfort? I am sure LRV's can climb greater than 5%.

There are a whole bunch of different factors which have to be taken into account when factoring these kinds of things. The units that Metrolinx are buying can handle more than a 5% grade without difficulty on their own, but wouldn't be able to haul a dead unit up a grade steeper than that - thus, the arbitrary 5% grade limit. The legacy fleet cars can handle much steeper than 8% grades, but the same thing applies. This is also why ALRVs are not allowed on St. Clair at all, or on the Harbourfront line if it is at all possible - they can't push a disabled unit up those grades.

Dan
Toronto, Ont.

 

[rbt]

There are a whole bunch of different factors which have to be taken into account when factoring these kinds of things. The units that Metrolinx are buying can handle more than a 5% grade without difficulty on their own, but wouldn't be able to haul a dead unit up a grade steeper than that - thus, the arbitrary 5% grade limit. The legacy fleet cars can handle much steeper than 8% grades, but the same thing applies. This is also why ALRVs are not allowed on St. Clair at all, or on the Harbourfront line if it is at all possible - they can't push a disabled unit up those grades.

For the legacy LRT, I believe they had to be able to push a disabled and derailed car up that grade. The reasoning being that it would be very difficult to get trucks into the Queens Quay tunnel to manipulate an LRV to get it back on the track.

 

[smallspy]

For the legacy LRT, I believe they had to be able to push a disabled and derailed car up that grade. The reasoning being that it would be very difficult to get trucks into the Queens Quay tunnel to manipulate an LRV to get it back on the track.

There were a number of locations that they looked at, but that grade was one of them.

In the grand scheme of things it would not be difficult to purchase a unit such as a UniMog or a RailKing which has the ability to tow a disabled unit up and out such locations, but I suspect that the TTC would rather have the car behind do the work to try and minimize the disruption to service.

Dan
Toronto, Ont.

 

[raptor]

Finally some noticeable progress?

Keele Station Headwall Construction and Utility Relocation for Twin Tunnels
Crews will be relocating various utilities for the construction of the Keele Station headwalls. Headwalls are underground support walls located at the east and west ends of the future station location. Following the relocation of utilities, crews will be installing these underground station headwalls in advance of the twin tunnel construction.

http://www.thecrosstown.ca/news-media/whats-new/keele-station-headwall-construction-and-utility-relocation-for-twin-tunnels