[BurlOak]

The tunnels approaching Lawrence are incredibly deep. IIRC, TTC doesn’t permit grades of more than 2% for stations and 5% for tunnels. So for an elevated structure, it would have to rise to the elevated level, and descend back to tunnel level, within those grading constraints. Furthermore, towards the south of Lawrence the tracks will be curved, which will limit how steep the grading can be (IIRC, trains don’t like elevation changes on curves)

Finally, there’s the creek to the north, which the tunnels will have to navigate while descending back down to tunnel level.

The solution is not elevated, it's a Bloor viaduct style solution.

At Lawrence, the subway is underground about 5 or 6m.
It crosses Highland Creek at about the elevation of the current road bridge*.
It goes underground on the north bank between the hydro lines and St. Andrew Road.
The roadway goes directly on top of the subway.**
* - the elevation of the bridge may have to be raised to pass the Regional Storm (Hazel) under the bridge. Currently, it is likely designed that if a Regional Storm comes, it overtops the roadway and possibly washes out the north approach to the bridge. This idea of mine creates a 5m high bridge which could act as a dam if the water level gets too high, and may back up water levels upstream. However, the Sheppard line over the Don Rive solved this.
** - there needs to be some small changes to the roadway. Likely Benliegh Dr. would have to be realigned, or keep a low level bridge to the north of the subway bridge that gives access to Benleigh only from (and to) the NBL.
I show this new subway bridge (and road bridge) just west of the existing, because its construction may lead to less traffic disruption.

 

[BurlOak]

To this day, I question how re-doing the turn at Midland to accomodate subway vehicles is not cheaper than tunneling.

Surely, it is the kind of problem where if we "threw enough money at it" we would find an engineering solution? It would probably still be cheaper than a McCowan subway, and Lawrence East Station is back on the table.

My guess is that the constraints that were applied when the route was reviewed did not allow any actual cost savings to be had.
For a Value Engineering study like this, the criteria should be to find the best* way of getting the subway to STC. Maybe even the best way of connecting STC seamlessly to the rest of the network.

* - best meaning best bang for the buck.

 

[sixrings]

Pretty sure the surface option was not a option if i t meant shutting down the rt upsetting voters. The whole expansion is designed to win voters, they aren't going to expand while at the same time tick people off. There is no win in that. Therefore go underground and just justify whatever costs come with it.

 

[TheTigerMaster]

Pretty sure the surface option was not a option if i t meant shutting down the rt upsetting voters. The whole expansion is designed to win voters, they aren't going to expand while at the same time tick people off. There is no win in that. Therefore go underground and just justify whatever costs come with it.

The SRT is probably going to need to be shut down for RER regardless, according to ML plans.

 

[robmausser]

The best bang for the buck solution was and always has been to refurbish the existing SRT, and to buy new Mark 3 trains for it, like they have in Vancouver.

Refurbish the system, rebuild the tunnel to accommodate the new Mark 3 trains, and extend it to Sheppard, as the plans in the 1980's, or even to Malvern.

and thus don't build a Smarttrack station at Lawerence (no need) and with the money you have left over build the Sheppard LRT and Eglinton East LRT.

The SRT system would only be down for 6 months, which is much more reasonable than the two years cited for the LRT conversion


https://www.thestar.com/news/gta/tr...nd-modernize-the-srt-says-transit-expert.html

https://www.thestar.com/news/city_h...lect-of-scarborough-rt-is-shameful-james.html



This has always and will be the best solution in my mind

 

[WislaHD]

The best bang for the buck solution was and always has been to refurbish the existing SRT, and to buy new Mark 3 trains for it, like they have in Vancouver.

Refurbish the system, rebuild the tunnel to accommodate the new Mark 3 trains, and extend it to Malvern, as the plans in the 1980's, and thus don't build a Smarttrack station at Lawerence (no need) and with the money you have left over build the Sheppard LRT and Eglinton East LRT.

This has always and will be the best solution in my mind

But it is second-class.

 

[robmausser]

But it is second-class.

As opposed to having to take a bus to the one and only subway station in your region.

 

[sixrings]

This way politicians can act like they tried their best even if they knew it wasn't optimal. People know and like subways. People like subways on major roads. People will vote for this. The end.

 

[TheTigerMaster]

The best bang for the buck solution was and always has been to refurbish the existing SRT, and to buy new Mark 3 trains for it, like they have in Vancouver.

Refurbish the system, rebuild the tunnel to accommodate the new Mark 3 trains, and extend it to Sheppard, as the plans in the 1980's, or even to Malvern.

and thus don't build a Smarttrack station at Lawerence (no need) and with the money you have left over build the Sheppard LRT and Eglinton East LRT.

The SRT system would only be down for 6 months, which is much more reasonable than the two years cited for the LRT conversion


https://www.thestar.com/news/gta/tr...nd-modernize-the-srt-says-transit-expert.html

https://www.thestar.com/news/city_h...lect-of-scarborough-rt-is-shameful-james.html



This has always and will be the best solution in my mind

I’ve said before, I hope the SSE goes wildly out of budget so the City could have a somber second thought and adopt this most obvious of solutions.

We could even introduce a branch running north up the Stoufville corridor to serve Milliken

 

[Rainforest]

Pretty sure the surface option was not a option if i t meant shutting down the rt upsetting voters. The whole expansion is designed to win voters, they aren't going to expand while at the same time tick people off. There is no win in that. Therefore go underground and just justify whatever costs come with it.

I think "surface" options discussed in the last few posts actually mean "partly on surface and partly in shallow tunnels", but still using the new route. RT will not be affected any more than it would be by the deep-tunnel option currently on the table.

 

[Rainforest]

The tunnels approaching Lawrence are incredibly deep. IIRC, TTC doesn’t permit grades of more than 2% for stations and 5% for tunnels. So for an elevated structure, it would have to rise to the elevated level, and descend back to tunnel level, within those grading constraints. Furthermore, towards the south of Lawrence the tracks will be curved, which will limit how steep the grading can be (IIRC, trains don’t like elevation changes on curves)

Finally, there’s the creek to the north, which the tunnels will have to navigate while descending back down to tunnel level.

I understand the issue. However, aren't the tunnels so deep precisely because they want to build under the ravines and not to deal with any bridges? That option is most straightforward, but not necessarily cheapest, especially if we hope to get the Lawrence East station back.

If the McCowan-only route doesn't allow a shallow tunnel, then maybe the subway should run partly under Brimley. Going from Eglinton, it would clear the first ravine (which is not very deep) well before reaching Lawrence. It could raise to just a few meters below ground while still being under Brimley, then start curving north-east just before it crosses under Lawrence. The station would be north of Lawrence, next to the hydro corridor, either underground (shallow) or perhaps on surface. Then the tracks would cross the main Highland Creek ravine on a bridge, descent underground, and head north under McCowan to reach STC.

By the way, not sure if the STC station will have to be so deep in that case. There are no streams or ravines around that area.

 

[TheTigerMaster]

I understand the issue. However, aren't the tunnels so deep precisely because they want to build under the ravines and not to deal with any bridges? That option is most straightforward, but not necessarily cheapest, especially if we hope to get the Lawrence East station back.

If the McCowan-only route doesn't allow a shallow tunnel, then maybe the subway should run partly under Brimley. Going from Eglinton, it would clear the first ravine (which is not very deep) well before reaching Lawrence. It could raise to just a few meters below ground while still being under Brimley, then start curving north-east just before it crosses under Lawrence. The station would be north of Lawrence, next to the hydro corridor, either underground (shallow) or perhaps on surface. Then the tracks would cross the main Highland Creek ravine on a bridge, descent underground, and head north under McCowan to reach STC.

By the way, not sure if the STC station will have to be so deep in that case. There are no streams or ravines around that area.

All very good points, regarding tunnel depth. Unfortunately we’re so late into design phase that any modifications to tunnel depth to accommodate Lawrence East station is highly unlikely to happen. We’d be throwing away much of the design work we’ve completed across the entire line.

 

[OneCity]

As opposed to having to take a bus to the one and only subway station in your region.

Well if you believe that all that will ever be built? I certainly don't and a part of this mess is this the fact most residents would prefer to get rid of many things RT related. Unfortunately this line hasn't worked for many reasons.

Ridiclous 1 stop vs transfer LRT debate aside bringing the subway to SCC has greater benefit for Scarborough residents beyond transit. It's connects the central hub of Scarborough directly to the core of the City. That's very important for the future of the heart of a heavily populated and seriously neglected inner suburb. It's a far better long term foundation and the local network can continue to evolve around. There were cheaper subway or transfer free solutions which would provided an important improvement at a lower cost but I think that chance has passed.

I agree if the goal is to find the cheapest transit for Scarborough than RT update is the way and better value than the transfer LRT plan. I just don't see any reality where an appetite by residents to support the cheapest solution thru their core after the whole RT debacle and what we built to Vaughan and North York Centres.

 

[syn]

The list of alternative syn-facts is growing.



Source?

No answer. As expected.

Your alternative fact list about me is entirely made up. If you need to make this about me to deflect from the fact that there's virtually nothing in this debate that lends validity to the SSE, then go for it.


Cost of Scarborough subway extension rises to $3.35 billion as number of new riders fall
"The overall updated cost is a $150 million increase over the earlier $3.2 billion estimate, and doesn’t include the cost of financing.

The new estimate includes significant changes to a planned bus terminal at a new Scarborough Town Centre station which staff said requires 34 bus bays — the largest bus terminal in the entire TTC network.

However, staff said in the report that because the new $3.35 billion estimate is still based on very little design work being completed at this point, the range of accuracy for that estimate is massive. The estimate, staff said, could be off by up to 50 per cent — putting the high-end estimate at $5.02 billion."









Has the Scarborough subway already gone over its available funding?
"The $3.35 billion estimate covers construction of the subway tunnel, new station, associated infrastructure, including a new bus terminal on Triton Rd. at the Scarborough Town Centre, and the decommissioning of the existing Scarborough RT.

The report outlines several additional costs that are not included in that base number.

The additional costs include $14 million for platform edge doors that line up with subway doors at the station — a safety feature that has not been implemented elsewhere in the system but council requested the TTC consider as part of future expansions.

There is also an estimated $11 million for public realm improvements like wider sidewalks, plazas and street furniture.

According to consultants hired by the city to review cost estimates, the city should also establish a reserve in case of changes to the scope of the project. While the city staff report said the TTC believes that $100 million is adequate for that reserve, the consultants recommended that fund be twice as much.

Staff said the city must also build in a contingency for construction cost overruns and costs related to construction schedule delays — estimated, at what staff said are upset limits, of $115 million and $190 million respectively.

The base cost also does not include an estimated $40 million needed for the construction financing model recommended by staff or an additional $15 million required for project advisory fees.

Those additional costs, when you consider the higher-end estimates, total $585 million, putting the cost of the subway at $3.93 billion — leaving the subway $370 million short on funding."

...

"The new estimate includes significant changes to a planned bus terminal at a new Scarborough Town Centre station which staff said requires 34 bus bays — the largest bus terminal in the entire TTC network.

However, staff said in the report that because the new $3.35 billion estimate is still based on very little design work being completed at this point, the range of accuracy for that estimate is massive. The estimate, staff said, could be off by up to 50 per cent — putting the high-end estimate at $5.02 billion."







As Scarborough subway price rises, Mayor John Tory looks for cost-saving measures

"Earlier, Coun. Joe Mihevc told CBC Radio's Metro Morning he's worried the city has written a blank cheque for the 6.5-kilometre subway extension, and that he expects the cost to blow past the current price tag and go as high as $5 billion.

"It is still going way, way beyond expectations," he said.

Mihevc, who supported an earlier version of the subway that had three stops, said he expects city council to reluctantly OK the new recommendations for the subway, including using the McCowan alignment.

"We have to find a way to make peace with it at some point," he said.

"And that's perhaps the tragedy of our time."








Globe editorial: The Scarborough subway, a boondoggle on rails

"This week, it was revealed that the cost of the proposed one-stop Scarborough subway continues to grow. On Tuesday, a city staff report pegged the estimated cost at $3.35-billion, up from $2-billion last year. The report says the final price tag could end up as much as 50 per cent higher. So we may be looking at a $5-billion, one-stop subway.

The staff report upping the price also reduced the line's low projected ridership; it expects to attract just 2,300 new riders a day.

The Scarborough subway is illogical transit policy. Its only logic is political. Politicians, municipal and provincial, get to tell voters in Scarborough that they're getting a subway – even though most of Scarborough is far from the line and its solitary station, the cost of which is impoverishing transit elsewhere."



This will likey be, at least, a $5 billion+ subway line.

 

[BurlOak]

I can't follow what you wrote at all.

• If you are quoting from an article, then please use [ QUOTE ] at the start, and [ /QUOTE ] at the end (without the spaces between square brackets and letters).
• I am not sure if you deliberately made the font large in some locations, or it was part of your cut and paste. If you want to highlight text in a larger paragraph, I would suggest Bold or Underline or Coloured text, or a combination.