Danforth Line 2 Scarborough Subway Extension

[Tuck]

Its logical it you look at economics with the highest priority for sure

*I find it odd that some outside Politicians, and some residents think most Scarborough residents like the current RT and believe it integrates SCC well into the City's network.
*I find it odd people think its acceptable to leave Sheppard as a stubway and connect another technology.
*I find It odd people are determined to create Municipal Holy war against the SSE but barley a peep when Vaughan or North York Centre was built
* I find it odd that people think the placement of the transfers are well designed in the broader network

Don't get me wrong a local network will serve one need really well, but that can be addressed in the future. Logic is based on where you live in this City and how important you weight what has been built elsewhere and the convenience & economic parity of building better integrated transit . If Tory could get off Smartrack, add a stop on the subway and fund Eglinton East we would have what I consider a logical plan. Neither the SLRT or 1 stop/Smarttrack hit the mark.

RER should serve the need to go downtown better than a subway would, though there is the issue of fare integration.

The transfer would still be there, but simplified - no more stairs. Hope off one train and get on another. Plus a Eglington wouldn't have one.

I agree with you on Sheppard.

 

[OneCity]

RER should serve the need to go downtown better than a subway would, though there is the issue of fare integration.

The transfer would still be there, but simplified - no more stairs. Hope off one train and get on another. Plus a Eglington wouldn't have one.

I agree with you on Sheppard.

There is also the importance of SCC to residents and the economic spin-off of the subway compared to the LRT with a transfer before, commuter attractiveness & quality investment around Scarborough Centre will be greater with the subway stop. RER will be good but as you say fare structure needs work to have value vs. any time saved as the frequency would not be the same as the subway.

 

[BurlOak]

Many "Non-supporters" would agree with you on Vaughan, but the question is whether we commit a second wrong by letting the "Supporters" carry the day on the basis of local politicians and MPP's doing exactly the same crap that was done to sell Vaughan. The "supporters" need to have a better argument than that for the decision to be seen as honest.

I am still wondering whether cut and cover construction would save some money and permit the added stations to be restored. If that were so, we could abandon ST altogether and that money would be freed up to keep other parts of the Scarborough plan moving. Tory is the only one standing in the way of that so Council would have to throw him under the bus for this to happen. The Eglinton extension could be where Queens Park could pick up the slack rather than just being pressured to up the ante every time the Line 2 cost rises.

- Paul

The key to cut-and-cover is to find a way of handling the hospital. I sketched up an B-D line that is just west of McCowan (note that North is right). Google Earth elevations are not that accurate, so I am not sure if things are correct. Once you clear the hospital, everything else can be cut-and-cover - unless you want to go to Sheppard than TBM is required under 401).
The Station is underground at Lawrence, but extends north and becomes roughly at (near)-grade as McCowan dips about 3.5%. The subway would be on a bridge, about the same elevation as McCowan. After crossing Highland Creek, the line would go underground and curve to continue north under McCowan. I have now blocked access to the hospital, so that needs to be worked out.

I would have loved to raise the elevation of McCowan and just put the subway under the bridge, however, the line would not be underground in time for Benleigh Drive and access to that road would be blocked.

 

[crs1026]

Woke up in the night and wondered.....why not use the prefab panel method of construction (xactly what a TBM does) but do it in an open trench that is excavated, rather than bored?

You would have the same moving, 15 meters a day progress as a bored tunnel, with none of the forming and curing time that poured concrete has. Earth moving is cheap because as you excavate at one end, you just transfer the material to the other end and use it to fill the completed end in. Cut and cover doesnt have to meean shutting down the whole length of the project at one time.

I kniw, it's engineering on the back of an envelope... just wondering if any system has tried something like that.

- Paul

 

[crs1026]

Crs1026: you say we can get rid of ST because of the subway to SCC, if stops are added. ST is an RER subsidy by Toronto taxpayers to serve Markham, and just as Oxford Properties has surfaced re SCC, no doubt there will be forces, like York University who are building a campus there, who will mobilize to keep ST alive

A York U campus may be valid reason for a single stop.... but Markham already has thsoe. Is the campus not close enough to an existing stop?

- Paul

 

[BurlOak]

Woke up in the night and wondered.....why not use the prefab panel method of construction (xactly what a TBM does) but do it in an open trench that is excavated, rather than bored?

You would have the same moving, 15 meters a day progress as a bored tunnel, with none of the forming and curing time that poured concrete has. Earth moving is cheap because as you excavate at one end, you just transfer the material to the other end and use it to fill the completed end in. Cut and cover doesnt have to meean shutting down the whole length of the project at one time.

I kniw, it's engineering on the back of an envelope... just wondering if any system has tried something like that.

- Paul

I have not found any detailed articles on this, but there was discussion earlier about a similar thing being done in China (Shanghai?).

I see a 180m long moving operation.

• 30m closed for construction activities/staging.
• 15 m excavate.
  
• 15 m support utilities.
• 15m prepare bedding.
• 15m place precast tunnel
• 15m grout tunnel
• 15m waterproof tunnel
  
• 15m backfill tunnel
• 15m restore pavement
• 30m parking for those accessing closed portion.

I will assume each activity can be done in a day, although some may need more (i.e. if excavation has to dig around many utilities).

Its 6000m from Eglinton to STC - that works out to 400 days - just over a year. This moving operation would have each individual area closed for about 12 days.

The stations would of course take longer, but they are now located quite shallow, so their construction is much faster than the current ECLRT and TYSSE. They would have to be decked over during construction if in the middle of the road (i.e. not STC if it is in the parking lot).

 

[Tuck]

The key to cut-and-cover is to find a way of handling the hospital. I sketched up an B-D line that is just west of McCowan (note that North is right). Google Earth elevations are not that accurate, so I am not sure if things are correct. Once you clear the hospital, everything else can be cut-and-cover - unless you want to go to Sheppard than TBM is required under 401).
The Station is underground at Lawrence, but extends north and becomes roughly at (near)-grade as McCowan dips about 3.5%. The subway would be on a bridge, about the same elevation as McCowan. After crossing Highland Creek, the line would go underground and curve to continue north under McCowan. I have now blocked access to the hospital, so that needs to be worked out.

I would have loved to raise the elevation of McCowan and just put the subway under the bridge, however, the line would not be underground in time for Benleigh Drive and access to that road would be blocked.

View attachment 102350

Why is a TBM needed for the 401? A bridge would be fine - on the Spadina side of line 1, its elevated over the 401.

 

[crs1026]

I will assume each activity can be done in a day, although some may need more (i.e. if excavation has to dig around many utilities).

Its 6000m from Eglinton to STC - that works out to 400 days - just over a year. This moving operation would have each individual area closed for about 12 days.

The stations would of course take longer, but they are now located quite shallow, so their construction is much faster than the current ECLRT and TYSSE. They would have to be decked over during construction if in the middle of the road (i.e. not STC if it is in the parking lot).

With proper planning, some of the "tough spots" could be started early and undertaken concurrently, so that when the "moving trench" reaches them, they are ready to go.

Unlike Crosstown, station excavations could begin ahead of the arrival of the "trench"... the whole thing could have parallel activites to the tunnel construction.

- Paul

 

[BurlOak]

With proper planning, some of the "tough spots" could be started early and undertaken concurrently, so that when the "moving trench" reaches them, they are ready to go.

Unlike Crosstown, station excavations could begin ahead of the arrival of the "trench"... the whole thing could have parallel activites to the tunnel construction.

- Paul

Exactly. Also, as soon as the tunnel is laid, you can start work on tracks and electrical. With TBM, the spoils are extracted through the interior of the tunnel, so nothing else can start until the entire tunneling is complete.

 

[BurlOak]

Why is a TBM needed for the 401? A bridge would be fine - on the Spadina side of line 1, its elevated over the 401.

If a transit line is below grade, the top of tunnel is 1.5m to 2.0m below grade. This means that the tracks are about 6.0m below grade. Now when a transit line is elevated, it requires a clearance for traffic below of 5.0m, plus allow 1.0m to 2.0m (or more) for the bridge structure (depending on how close you want your support pillars). This means that the transit line has to raise about 13m to switch from underground to elevated. TTC preference for subway is 2% grade, although a maximum of 2.5% is allowed. This means you need a clear length of about 500m to switch from underground to elevated. There are also some transitions from horizontal to the 2.5% grade at the two ends of the vertical curve, so this adds another 100m at each end. The total is about 700m.

When I look at STC, there is no 700m long stretch where all the roads can be blocked as the line switches from underground to elevated. It would require the subway to be elevated before crossing Ellesmere, which has its own set of problems. (For Spadina, the subway was already elevated, or at least on a berm, to the south so bridging over 401 involved minimal grade change).

https://www.google.ca/maps/@43.7747288,-79.2574351,16z

I think it has been pointed out that TBM is not that expensive in itself, it is all the associated activities. Vancouver had a number of short TBM section and did it quite economically. The cost are due to emergency exits from deep tunnels, ventilation from deep tunnels, station excavation for deep tunnels, etc. If the tunneling is simply from the STC parking lot to the parking lot south of Milner, none of that would be required. The SELRT had pretty small costs for their short TBM segment under highway 404.
What were the costs for ECLRT? The launch shaft was maybe $60M (don't recall the exact cost). Extraction would be less. TBM's already exist and can be used for short runs even if productivity has slowed due to their age. I would guess the cost would be in the $200M to 300M range.

 

[kEiThZ]

I don't get the fixation on burying the line. I don't think most residents who want a subway care how it gets to STC. The major complaint has always been the transfer. The main benefit of burying the line should have been a Lawrence Station at the hospital and an STC station right on McCowan. If Lawrence station is being completely written off they might as well go with the Murray plan.

 

[BurlOak]

Problem with elevated subway line is that stations are 150m+ long. The SRT is only about 50m, and SkyTrain in Vancouver is 40m to 90m long. It is a bit worse on the aesthetics.
I have always thought that its best (maybe not best, but cost effective) to have stations shorter than trains. If you want to get off at certain stops, only certain cars line up with the platform. The major transfers and high use stations are the only ones that need platforms long enough for the full train.

 

[ssiguy2]

Its logical if you look at economics with the highest priority for sure

*I find it odd that some outside Politicians, and some residents think most Scarborough residents like the current RT and believe it integrates SCC well into the City's network.
*I find it odd people think its acceptable to leave Sheppard as a stubway and connect another technology.
*I find It odd people are determined to create Municipal Holy war against the SSE but barley a peep when Vaughan or North York Centre was built
* I find it odd that people think the placement of the transfers are well designed in the broader network

Don't get me wrong a local network will serve one need really well, but that can be addressed in the future. Logic is based on where you live in this City and how important you weight what has been built elsewhere and the convenience & economic parity of building better integrated transit . If Tory could get off Smartrack, add a stop on the subway and fund Eglinton East we would have what I consider a logical plan. Neither the SLRT or 1 stop/Smarttrack hit the mark.

You can't compare the Vaughn or potential Yonge extension as these are not places that there is already an existing RT line. I see the issue of the awkward transfer but that can be fixed. The people in Malvern aren't going to see their commute improve one bit and increasingly neither are any of the people of South Scar as the money for that project is quickly evaporating. Also the extension of any subway to Malvern will never happen in our lifetimes.

Maybe a compromise might be to keep the RT and extend it down Eglinton and North/West from STC but also have a ST spur from the mainline to STC so people in the area have RT to downtown and a seamless connection down Eglinton. Even that would be cheaper than a subway extension.

Before they spend untold billions on a line perhaps a councillor from Scar and Tory could spend a few thousand and take a trip to Vancouver to experience the MK111 trains and se why Vancouverites love their SkyTrain so much.

 

[OneCity]

You can't compare the Vaughn or potential Yonge extension as these are not places that there is already an existing RT line. I see the issue of the awkward transfer but that can be fixed. The people in Malvern aren't going to see their commute improve one bit and increasingly neither are any of the people of South Scar as the money for that project is quickly evaporating. Also the extension of any subway to Malvern will never happen in our lifetimes.

Maybe a compromise might be to keep the RT and extend it down Eglinton and North/West from STC but also have a ST spur from the mainline to STC so people in the area have RT to downtown and a seamless connection down Eglinton. Even that would be cheaper than a subway extension.

Before they spend untold billions on a line perhaps a councillor from Scar and Tory could spend a few thousand and take a trip to Vancouver to experience the MK111 trains and se why Vancouverites love their SkyTrain so much.

This Is the never ending debate that people seem baffled to understand why many Scarborough residents support the subway. I get your points, trust me and they are valid and some are shared in Scarborough depending where they live. All the plans leave elements to be desired. For the pro SLRT argument I disagree with how they weigh their key points, especially the weighting of integration based on existing tech, and I see the future completely differently. Its too late for Skytrain based on the LRT and subway network already built and underway. The City and Province had that chance and that's not Scarborough's issue.

Most Malvern residents will have a better commute with the subway. That's why they highly support the subway extension(s) which some pundits don't seem to understand and have somewhat ignored. The majority would have to bus to the LRT then LRT to subway to get out of Scarborough. Very inconvenient in a 4 hour daily commute for many. The bus on this side of the City is not bogged down in traffic. That doesn't mean the extension has no merit but not urgent & when we do extend locally I fully support an extension to Malvern TC, which isn't in the LRT plan. This extension is a way lower priority at this time and will be done in the future. The subway is a one time deal and will help many in the North, Centre and East immediately. If the Eglinton East LRT is funded it can be easily extended to Malvern TC as option as well and can be designed during construction. The subway extension is far better starting point at SCC to build a future than the SLRT. A cross City line can be built in the future when needed and Id argue part of the infrastructure exists already for when that day comes.

A compromise is in many ways what Tory is attempting, if it wasn't for Markhamtrack weakening the subway to one stop and impacted Eglinton East for now it would be harder to argue. The only other reasonable compromise at this point is to go back to the Ford plan. Tory seems to be confident about Eglinton LRT and if its funded you'll see solid support as people wont have to choose local vs. integration of the Core hubs. Both important ideologies will be well on their way for what I see as a solid future. If he limps in "as-is" itll be interesting to see what the LRT and subway plans will be. There is a lot that can be improved with the subway when Smarttrack funds are shifted around.

 

[Tuck]

If a transit line is below grade, the top of tunnel is 1.5m to 2.0m below grade. This means that the tracks are about 6.0m below grade. Now when a transit line is elevated, it requires a clearance for traffic below of 5.0m, plus allow 1.0m to 2.0m (or more) for the bridge structure (depending on how close you want your support pillars). This means that the transit line has to raise about 13m to switch from underground to elevated. TTC preference for subway is 2% grade, although a maximum of 2.5% is allowed. This means you need a clear length of about 500m to switch from underground to elevated. There are also some transitions from horizontal to the 2.5% grade at the two ends of the vertical curve, so this adds another 100m at each end. The total is about 700m.

When I look at STC, there is no 700m long stretch where all the roads can be blocked as the line switches from underground to elevated. It would require the subway to be elevated before crossing Ellesmere, which has its own set of problems. (For Spadina, the subway was already elevated, or at least on a berm, to the south so bridging over 401 involved minimal grade change).

https://www.google.ca/maps/@43.7747288,-79.2574351,16z

I think it has been pointed out that TBM is not that expensive in itself, it is all the associated activities. Vancouver had a number of short TBM section and did it quite economically. The cost are due to emergency exits from deep tunnels, ventilation from deep tunnels, station excavation for deep tunnels, etc. If the tunneling is simply from the STC parking lot to the parking lot south of Milner, none of that would be required. The SELRT had pretty small costs for their short TBM segment under highway 404.
What were the costs for ECLRT? The launch shaft was maybe $60M (don't recall the exact cost). Extraction would be less. TBM's already exist and can be used for short runs even if productivity has slowed due to their age. I would guess the cost would be in the $200M to 300M range.

This was a very concise, clear explanation. Thank you.