Danforth Line 2 Scarborough Subway Extension

[nfitz]

But now we've instead raised taxes to pay for the extra subway costs and rehab the SRT for 10-years extra life.

The no-brainer decision is clearly to go back to the 2006 plan.

 

[Voltz]

Modifying the stations and tunnels for the Mark II/III cars would have been quicker in the long run than converting the line to an LRT or the subway option, but what sold the city at the time was the fact the LRT option would be covered by the Province, not the city, so it was a no brainier.

I don't remember that being the case at all,

They didn't decide on which technology until well into the design and EA of the extension and changes to Kennedy Station, and the line was brought into the Transit City plan by that point, using LRT would not have required a new yard, so it was cheaper to use LRT.

 

[nfitz]

They didn't decide on which technology until well into the design and EA of the extension and changes to Kennedy Station, and the line was brought into the Transit City plan by that point, using LRT would not have required a new yard, so it was cheaper to use LRT.

Using Mark II equipment didn't require a new yard either; just more storage area. Whether those extra storage tracks be at the Sheppard East LRT yard or at Ellesmere shouldn't change cost that much.

 

[Voltz]

Using Mark II equipment didn't require a new yard either; just more storage area. Whether those extra storage tracks be at the Sheppard East LRT yard or at Ellesmere shouldn't change cost that much.

Then where would the Mark II cars be maintained? They are different from everything else.

 

[CodeMonkey]

I don't remember that being the case at all,

They didn't decide on which technology until well into the design and EA of the extension and changes to Kennedy Station, and the line was brought into the Transit City plan by that point, using LRT would not have required a new yard, so it was cheaper to use LRT.

It was pretty much a done deal before the EA came out that the city and the TTC would pick the LRT option (pre-Ford) over any SRT option. The argument was why should we continue to use an orphan proprietary bombardier technology when we could use a cheaper, open bombardier technology instead.

 

[nfitz]

Then where would the Mark II cars be maintained? They are different from everything else.

The existing yard where they maintain the Mark I's - which would all have been disposed of. With more storage.

 

[Voltz]

The existing yard where they maintain the Mark I's - which would all have been disposed of. With more storage.

I distinctly remember the EA displays showing a new yard east of Bellamy on the south side of the line, the extension would have run right through the existing yard.

 

[nfitz]

I distinctly remember the EA displays showing a new yard east of Bellamy on the south side of the line, the extension would have run right through the existing yard.

That was for the later extension project. The $190 million TTC plan in 2006 was only for the existing SRT from Kennedy to McCowan. This didn't require a new yard.

As the city planning department has concluded that extension part Scarborough Centre isn't necessary, we can go back to 2006 plan rather than spending $billions.

 

[innsertnamehere]

So in light of the TTC apparently looking at single bore tunnels in the future to save money on construction costs, I thought I would visualize the 3 different options in sketchup. Today the TTC uses two 6.5m diameter tunnels, each one housing each direction of subway track. The option originally being evaluated for Scarborough was a single, 13.5m wide tunnel, which would allow for crossover tracks to be constructed without having to use cut and cover, saving costs and disruptions. Now that the scope of the project has been reduces to simply a tunnel to Scarborough Centre, the TTC is looking at doing a single bore tunnel with a 10.5m diameter, as only a single crossover would need to be constructed at Scarborough Centre.


Looking at these three options, I wonder if the 13.5m tunnel could result in major cost savings. It almost looks large enough to build an entire platform in.. imagine just excavating a small concourse level above the TBM tunnel, then dropping some escalators directly to track level within the tunnel.. seems it would be way cheaper and less complicated. The question is if a 5-6m platform would be wide enough.

 

[Voltz]

Pretty sure the idea with the 13.5m tunnel was to include the station platforms in the tunnel, but with the tracks for each direction being stacked on top of each other, creating two levels within the tunnel. This would leave enough width for a platform on each level beside each track. Such a design was examined for the Eglinton LRT.

 

[Voltz]

That was for the later extension project. The $190 million TTC plan in 2006 was only for the existing SRT from Kennedy to McCowan. This didn't require a new yard.

As the city planning department has concluded that extension part Scarborough Centre isn't necessary, we can go back to 2006 plan rather than spending $billions.

We could, but it seems to have been determined that a subway will lead to an exponential increase in development at STC.

 

[BurlOak]

But now we've instead raised taxes to pay for the extra subway costs and rehab the SRT for 10-years extra life.

The no-brainer decision is clearly to go back to the 2006 plan.

Brad Duguid: "That will happen over my dead body"

At least now we know who is responsible for the waste endless games and waste of $2B.

 

[BurlOak]

Specific to the size/dimension of Mk1 and whether it can be reproduced (with or w/out LIM)...I think a lot of that depends on who you ask. The City says no (and IIRC even from last week's transit powwow Keesmaat was asked a similar question, with the answer being 'no, the trains and their parts are not made anymore, case closed'). I don't want to quote Michael Schabas since I generally don't care much for his expert opinions, but in the past he said otherwise. And that trains can be reproduced and made-to-order by manufacturers upon request - which is a common practice worldwide. I tend to agree with this, since it seems logical.

Somehow I agree with you - I don't think the Mark II train dimensions are in Kessmaat's expertise - but I am also sure that it would not stop her from saying it as a fact.

 

[BurlOak]

Exactly. And there were affordable options to allow for this Laird-Kennedy grade-separation. But this was doomed to fail since all the per km costing was done for underground-only.

Maybe more surprising that after a number of years of construction, it would still be the most cost effective solution.

• Tear up maybe 500m of tunnel west of the portal (when the TBM's are done) and relocate the track to the south side of Eglinton.
  
• Grade-separate Laird to Kennedy.
• Connect SRT to Eglinton line.
• Cost is still cheaper than Scarborough subway.
• Proper interchange station with DRL could be built.
• It could be done faster than Scarborough subway.
• Yonge-Eglinton Station would still be on the critical path for completion of the Eglinton line.

 

[officedweller]

MKI SkyTrain cars are 12.8 m long
MKII SkyTrain cars are 17.35 m long

Bombardier recently built the 5000 series car for Chicago which are 14.63 m long.

http://www.bombardier.com/en/transp...ountry=ca&f-segment=all&f-type=all&f-name=all

See also:
https://en.wikipedia.org/wiki/5000_series_(CTA)

**************

The SkyTrain Evergreen Extension TBM had a 10 m diameter and bored a single tunnel for both guideways. A gravel bed with concrete floor and concrete wall separating the 2 directions (fire proofing) are now being completed.
It encountered a number of sinkhole problems - not sure if the large diameter was a contributing factor.

http://tranbc.ca/2014/03/26/the-eve...ll-make-it-a-boring-job/#sthash.eL4BBt56.dpbs

http://www.vancitybuzz.com/2015/09/tunnel-boring-resumes-for-skytrain-evergreen-line/