[TheTigerMaster]

Can't say it's undoable, but it does give one pause.

From Thorncliffe Park and Overlea to the creek itself, on the gentlest possible curve, is just under 1600 feet. At 3% grade, that's a potential 48 foot drop. Then it's 2100 feet to Gateway and Don Mills. That makes me think that it's physically possible (just barely) for a duckunder to be above grade at Thorncliffe Park, dip to intersect the hydro lines below grade, and be back up to a portal around Gateway. Cut and cover in the schoolyard won't create the need to demolish the school building. Perhaps the elevation of the Overlea Roadway would be adjusted to give a bit more clearance on the down slope.

- Paul

View attachment 228491

So basically, there'd be a tunnel under the hydro corridor. This tunnel would end at a portal at gateway and Don Mills. Just making sure we're on the same page.

That tunnel would be running rather shallow and right at the edge of the valley. I'd be concerned about erosion.

Also, trains really don't like to make grade changes on curves. It increases the risk of derailment. Slow orders would likely be in effect for this segment

Might very well be possible though. It would just be janky, like everything else about the Ontario Line.

 

[crs1026]

So basically, there'd be a tunnel under the hydro corridor. This tunnel would end at a portal at gateway and Don Mills. Just making sure we're on the same page.

That tunnel would be running rather shallow and right at the edge of the valley. I'd be concerned about erosion.

Also, trains really don't like to make grade changes on curves. It increases the risk of derailment.

Might very well be possible though. It would just be janky, like everything else about the Ontario Line.

Yes on all points. The radius of that curve is probably ok for graded track - it would be no worse to (for instance) Line 2 dipping into the Humber and back up. We've never seen a problem on that gradient/curvature.

I could see the line being in an open trench with rooftops at grade at the point of intersection with the hydro lines....just to save a few feet of cover over the underground part. Maybe the up-grade runs up the west side of Don Mills and over the current OSC parking lot until it is elevated enough to jog over to the center of Don Mills. (Can't wait to see the renderings of that :^[ )

- Paul

 

[TransitBart]

I'll take a streetcar network that carries 500K passengers per day and serves all of Downtown & Old Toronto over one ICTS line that can only carry about 250K PPD. I guarantee you that if the streetcar network was removed, we'd have far less traffic throughout the subway network, we'd be far worse off financially, and downtown wouldn't be nearly as lively as it is today.

So why is it so hard to buy the required number of streetcars to maximize the usage of the installed track (ahem 505, 503) and conceivably expand service - er we bought the same amount of capacity but now it’s in 200 vehicles instead of 250.

 

[Northern Light]

So why is it so hard to buy the required number of streetcars to maximize the usage of the installed track (ahem 505, 503) and conceivably expand service - er we bought the same amount of capacity but now it’s in 200 vehicles instead of 250.

Wandering a bit OTP here.........but money aside; the problem with vastly more streetcars at this moment is nowhere to store them. Remember these vehicles are larger.

The TTC used to have a working yard at Wychwood, which now at Artscape/Farmer's Market/Park site.

That capacity will have to be resurrected, likely at Hillcrest.

***

In terms of having ordered the correct number; no allowances were made for latent demand, nor for population and jobs growth in the core of the kind that we've seen.

 

[TransitBart]

Wandering a bit OTP here.........but money aside; the problem with vastly more streetcars at this moment is nowhere to store them. Remember these vehicles are larger.

The TTC used to have a working yard at Wychwood, which now at Artscape/Farmer's Market/Park site.

That capacity will have to be resurrected, likely at Hillcrest.

***

In terms of having ordered the correct number; no allowances were made for latent demand, nor for population and jobs growth in the core of the kind that we've seen.

This is rational and I knew all this. My question is really why the city can’t get its shit together?

 

[Northern Light]

This is rational and I knew all this. My question is really why the city can’t get its shit together?

LOL; Where's Waldo? What was before the universe? If Time is dimension, how can one exist outside of it? So many difficult to answer questions.

 

[TransitBart]

LOL; Where's Waldo? What was before the universe? If Time is dimension, how can one exist outside of it? So many difficult to answer questions.

Why is the sky blue? Is Donald Trump’s hair real? Is Justin Trudeau’s?

 

[BurlOak]

Good eye!

The elevated bridge would start at Overlea (orange), curve northeast, probably run a short segment at-grade at the northwest corner of the middle school (green), before utilizing an elevated alignment (orange) to cross under the hydro corridor. It would then connect to Don Mills Road. These elevated structures over the park would be more than 600 metres long.

Bridges and elevation are cheap - that's why it's done that way so often.

That 600m bridge would likely cost $60 to $80M. Add another $10M if the terrain is difficult - which it really isn't, but environmentalist will put plenty of restrictions on it anyways.

 

[Northern Light]

Bridges and elevation are cheap - that's why it's done that way so often.

That 600m bridge would likely cost $60 to $80M. Add another $10M if the terrain is difficult - which it really isn't, but environmentalist will put plenty of restrictions on it anyways.

Really? Citations? Because your cost estimates, according to me, and anyone with a modicum of knowledge are way low. Your failing to account for the extraordinary height of the structural supports across the valley, and their needs to be supported on bedrock, below the water table.

That's w/o being concerned about any environmental restrictions. (what restrictions? btw).

There would be environmental damage, that's unavoidable, it would result in 'compensation' (money spent protecting/restoring somewhere else). That's a mandatory cost under the law; not an option.

 

[TheTigerMaster]

I wonder if it might just be best to tunnel the line, between the Overlea bridge and Don Mills at Gateway Blvd. Remember, the most expensive part of tunnelling isn’t the tunnels themselves, but rather the stations and emergency exits. But a 600 to 700 metre tunnel wouldn’t need any stations or exits, so it should be relatively affordable. Even if it cost, say, 30% more than going elevated over the valley, I’d be willing to pay the extra cost to go underground for this segment.

I really have no clue at all how the tunnel costs and elevation costs compare though

 

[robmausser]

I wonder if it might just be best to tunnel the line, between the Overlea bridge and Don Mills at Gateway Blvd. Remember, the most expensive part of tunnelling isn’t the tunnels themselves, but rather the stations and emergency exits. But a 600 to 700 metre tunnel wouldn’t need any stations or exits, so it should be relatively affordable. Even if it cost, say, 30% more than going elevated over the valley, I’d be willing to pay the extra cost to go underground for this segment.

I really have no clue at all how the tunnel costs and elevation costs compare though

The concern in my mind isnt the tunneling under the valley, its then getting back up to grade once youre under.

Otherwise we will have stations at Cosburn and Thorncliffe Park that are like the stations on the REM, 80+ meters down and requiring elevators.

Not only inconvenient but also would most likely increase the cost because of the station depths.

OR we would have to use some kind of train tech that allows for steep inclines like rubber tyred trains or the LIM of the Scarborough RT (GASPS)

EDIT: actually now that I think about it tunneling under a designated flood plain might also not be the best idea.

 

[W. K. Lis]

Will the stairs be accessible to wheelchairs, strollers, and bicycles when the elevators or escalators are out-of-service? Enclosed, the slope shouldn't be that slippery, but should still have a surface to be not slippery when wet.

From link. Or will the design not be considered because the designers are not handicapped, have kids, or ride bicycles? The usual excuse.

 

[BurlOak]

Really? Citations? Because your cost estimates, according to me, and anyone with a modicum of knowledge are way low. Your failing to account for the extraordinary height of the structural supports across the valley, and their needs to be supported on bedrock, below the water table.

That's w/o being concerned about any environmental restrictions. (what restrictions? btw).

There would be environmental damage, that's unavoidable, it would result in 'compensation' (money spent protecting/restoring somewhere else). That's a mandatory cost under the law; not an option.

This is not that complex. All the land, I believe, is public. The contractor could easily access the valley from the south. The river itself at normal water is not wide and you are crossing it at close to 90 degrees. This elevated portion would near ideal 40m spans. With the columns being taller, they would likely need to be 2100mm or 2400mm diameter instead of 1800mm - but not that much of a premium. Tall piers are not a big deal, and they are relatively cheap so no need to make spans of the bridge excessively long (which does add cost).

Foundation would be piled foundation to bedrock, with pile cap at/near ground level. A bit of dewatering would be needed, but the excavation for these pile caps would be likely 2m deep. Infiltration is likely not a great concern, although I have no idea if the soils are cohesive or cohesionless.

It goes without saying the most of the trees

Your elevated track structure would cost $5000 /m2. Assuming 10m wide, that's $50M per km. Add about 25% for normal substructure (footings and piers) that's $12M. Associated civil works, grading, access, would be another 25%, or another $12M. design fees and Construction Administration (CA) would be another 25%, or another $12M. Finally, add another 25% to the substructure component due to the height, that's another $4M. Total cost per km is about $90M. I could probably know $10M off this due to economies of scale, since it's not just this bridge being built, but the contract likely includes several kilometers of bridge.
This is a bit old, but if you double the 2011 values it match the above to some degree. These subways and LRT are similar load to highway trucks. Highways are 64 tonnes over 18m, or 3.5 t/m. LRT is maybe 50t empty+ same weight of passengers over 25m, or 4 t/m
I may be off by 25%, but overall $80M to $100M for the bridge structure is a reasonable estimate.

You now have a bridge with a couple of feet of ballast, and the remaining construction is the same as at grade. I'd figure track, electrical, signalling would be $40M/km.

 

[TheTigerMaster]

The concern in my mind isnt the tunneling under the valley, its then getting back up to grade once youre under.

Otherwise we will have stations at Cosburn and Thorncliffe Park that are like the stations on the REM, 80+ meters down and requiring elevators.

Not only inconvenient but also would most likely increase the cost because of the station depths.

OR we would have to use some kind of train tech that allows for steep inclines like rubber tyred trains or the LIM of the Scarborough RT (GASPS)

EDIT: actually now that I think about it tunneling under a designated flood plain might also not be the best idea.

Oh my gosh, I didn’t mean tunnel under the valley

The valley would still be spanned by an elevated structure. But once on the eastern side (Don Mills) it would enter the valley wall to become a tunnel. Just like how Line 2 transitions from elevated to underground at the Bloor Viaduct. The tunnel would end at a portal on Don Mills road, near Gateway Blvd, to become an elevated structure. That should be around 700 meter of tunnel

Something roughly like this image. Yellow = elevated and red = tunnel

 

[Northern Light]

This is not that complex. All the land, I believe, is public. The contractor could easily access the valley from the south. The river itself at normal water is not wide and you are crossing it at close to 90 degrees. This elevated portion would near ideal 40m spans. With the columns being taller, they would likely need to be 2100mm or 2400mm diameter instead of 1800mm - but not that much of a premium. Tall piers are not a big deal, and they are relatively cheap so no need to make spans of the bridge excessively long (which does add cost).

Foundation would be piled foundation to bedrock, with pile cap at/near ground level. A bit of dewatering would be needed, but the excavation for these pile caps would be likely 2m deep. Infiltration is likely not a great concern, although I have no idea if the soils are cohesive or cohesionless.

It goes without saying the most of the trees

Your elevated track structure would cost $5000 /m2. Assuming 10m wide, that's $50M per km. Add about 25% for normal substructure (footings and piers) that's $12M. Associated civil works, grading, access, would be another 25%, or another $12M. design fees and Construction Administration (CA) would be another 25%, or another $12M. Finally, add another 25% to the substructure component due to the height, that's another $4M. Total cost per km is about $90M. I could probably know $10M off this due to economies of scale, since it's not just this bridge being built, but the contract likely includes several kilometers of bridge.
This is a bit old, but if you double the 2011 values it match the above to some degree. These subways and LRT are similar load to highway trucks. Highways are 64 tonnes over 18m, or 3.5 t/m. LRT is maybe 50t empty+ same weight of passengers over 25m, or 4 t/m
I may be off by 25%, but overall $80M to $100M for the bridge structure is a reasonable estimate.

You now have a bridge with a couple of feet of ballast, and the remaining construction is the same as at grade. I'd figure track, electrical, signalling would be $40M/km.

Did I see a citation?

Must have missed that.