YYCguy
Active Member
Indeed, by the time NCLRT comes to fruition, the UCP, or at least underground hating Smith and Dreeshen could no longer be in power, so a below ground option for NCLRT could be back on the table.
Green Line LRT | ?m | ?s | Calgary Transit
- Thread starter Surrealplaces
- Start date
darwink
Senior Member
It isn't that they hated underground, it is that the city never found a way/was unwilling to mitigate risk besides throwing more money at the problem from the project base budget, instead of accepting the risk of cost overruns from the tunnel and covering it out of city only reserve funds, for the very specific and best place to run the train in the core.
Also didn't help that choosing low floor LRT to save tens of millions on suburban and street running stations then meant spending hundreds of million more on each of the larger underground stations, amplified even more by putting a large arena which will have huge demand surges right next to one of the planned underground stations. Then that choice locking in higher operating costs forever, that the city also bemoaned that it shouldn't have to cover.
Green Line should have had a sprint reevaluation when it failed procurement and needed to be rescoped/truncated. Instead the city made the choice to unfail the procurement. After the market told it exactly what it didn't want to hear!
And that was after it failed once before, when the province rightly judged the procurement strategy to be not compatible with the city's objectives of completing a full line, at lowest possible cost and with cost certainty risking a failed procurement which ended up happening anyways.
So many choices along the way where this went bad. I can forgive most of them, they were driven by a council who we shouldn't expect to be experts on contract design, to cater to business interests who we shouldn't expect to be aligned with the public's objectives, and a civil service that isn't empowered to give fearless advice due to the governance structure of the city. The political choice to press on with the project despite all the problems after the failed procurement, that was the make or break, and I think lands firmly in the Mayor's office.
InfrastructureEnthusiast
Active Member
I get the appeal of underground, I just don't think doing it for NC is great value. It'll cost at least twice as much without much speed or service advantage from elevated, and looses the visibility aspect.
Rather than spend extra to put the line 'out of sight out of mind' why not use those resources to build out part of something like this, can run as a loop line if the rest of GL is fully separated.
Rather than spend extra to put the line 'out of sight out of mind' why not use those resources to build out part of something like this, can run as a loop line if the rest of GL is fully separated.
whatchyyc
Active Member
CalgaryTiger
Senior Member
It's not about out of sight, out of mind. It's about the best way to use the space and avoiding conflicts with major intersections. You do not want a train line that can be out run (literally a guy outran a new LRT in Ontario) end to end because of time delays at conflicts with major intersections.
My mind isn't going to expensive boring or a deep underground, on Centre Street only until 16th do a cut and cover (like was done for the section of Macleod through cemetery hill) and at the other major intersections you just need the tarin to be in a trench (like the one for the BRT at 90th Ave SW).
alexwilliamsyyc
New Member
FINALLY! A route that’ll take me to the airport!
darwink
Senior Member
underground to get into the median of Centre makes sense given the elevation change. The crossing at grade onto Centre seemed like a false economy to me, trading a long term expense (slow, plus traffic impacts) to save maybe $50 million bucks up front. After that going under or over 16th makes sense. Over would cost maybe 100 million more, under, 200-300. That is still assuming you'd take out traffic lanes for a portal or two, not staying underground (staying underground means you need to add at least 1 maybe 2 evacuation and smoke management structures), driving costs.
After that, traffic volumes are low enough that street running if can reach consistently a 50 kph speed limits is fine imo. If traffic impacts either slow it down too much, or are bad enough to pay more, there is another option.
Expropriating the first row of structures on one or the other side of the street.
If you want underground to avoid visual impacts, widening the street reducing the visual impact of elevated. You can also use the space to run the train on the side rather than the median, which would save even more money.
Of course, the city's normal design mode doesn't weigh 'would this cost less if we had more land' versus the cost to build it on a constrained corridor. We saw this same problem with the event centre 1.0, where the design and budget was under significant pressure from choosing too small of a site and being unwilling to make adjustments after that became obvious.
After that, traffic volumes are low enough that street running if can reach consistently a 50 kph speed limits is fine imo. If traffic impacts either slow it down too much, or are bad enough to pay more, there is another option.
Expropriating the first row of structures on one or the other side of the street.
If you want underground to avoid visual impacts, widening the street reducing the visual impact of elevated. You can also use the space to run the train on the side rather than the median, which would save even more money.
Of course, the city's normal design mode doesn't weigh 'would this cost less if we had more land' versus the cost to build it on a constrained corridor. We saw this same problem with the event centre 1.0, where the design and budget was under significant pressure from choosing too small of a site and being unwilling to make adjustments after that became obvious.
Roaring Flames
Senior Member
Honestly since the route north along Centre Street is being delayed, why don't we just go all the way and put the entire stretch from downtown up to Nose Creek underground? Have the train cross the river and go straight into the embankment. There's plenty of time between now and when it gets built to get the money to do just that.
darwink
Senior Member
A long response which jumps around a bit:
Because each of the 6 (not counting 16th or the possible one to the south) stations would cost $200 million in today's dollars. Then add in 16+ smoke and evacuation structures plus the land for them (any run longer than 400 metres between evacuation points needs an additional evacuation point) - this is in addition to smoke control built into the station boxes, increasing exvcavated volume. The tunnel itself is the cheap part, likely less than half a billion on its own, if it was the same size to carry anything else.
In very general terms when thinking about cost for infrastructure, with a surface line and elevated, costs increase in a linear manner. Above ground structures, you're working in two dimensions, so stations if you make them wider, also increases costs, just as when you make them longer. So costs go be square. When you go underground, you're talking about cubic metres of dirt excavated and held back, so costs increase by the cube.
So you 90 metre long surface station at $10 million, you add 5 metres of width to 'eyeball' building an elevated structure, and you're at $50 million, then for underground you add 4 metres of depth, you're at $200 million. Super basic, but when thinking of these things as amateurs, simple rules of thumb are useful to start to conceptualize costs.
For smoke and evac, any time a tunnel can be kept at fewer than 400 metres you save a lot of money. West LRT Westbrook tunnel accomplishes this, Cemetery Hill is too long, closer to 700 metres and so it has an evacuation point. The Red Line Tunnel from the Beltline to Downtown is 460 metres, and has an evacuation point on 10th Ave.
For under a street, you can't just go virtually straight up either, you have to lateral to a lot off to one side, which also can increase the frequency of additional structures, as it makes evacuation paths longer. Also ends up requiring higher power fans for smoke, since you have to fight vertical draft. For smoke, since the tunnel is going up and down, you can need even more structures, if the optimal spacing places the smoke control structures at low points.
Then you have things like substations. When going underground, there is a huge temptation to just add them into station boxes instead of expropriating land, to make the projects less complex to approve but at the result of making them more expensive to build.
There is a reason Toronto didn't build under Bloor Street for its second subway line, and for its first, avoiding building under Younge as much as possible, at least until later expansions when they unlearned their cost savings reasons.
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lemongrab
Active Member
Is this regulated by national fire code, or something else?
Presumably this would have applied to the tunnel under the Bow River, too? I can't even begin to imagine those costs, but I guess that's why comparing option costs by shading in eighths of a circle is kinda dumb.
Obviously it's just one factor of so many, but it looks like on of the early modest options wouldn't have needed an evac point at all (tunnel from ~11th to 3rd with a station at 7th is about 800 meters with a station in the middle; perhaps it would have needed egress at each end of the station which at least serves riders)
lemongrab
Active Member
Just came across this video from just a few weeks ago. Pretty good summary with a bunch of neat ideas/suggestions (though some probably aren't practical).
Integrating with the old Via Rail station sounds interesting, but I'm not sure how that could actually work? I always figured the 'station' was on the north side, but it makes sense that there's an underground ped tunnel there. Where would the access be from 10th?
The other little note that I didn't realize is that low floor vehicles are typically a bit taller (and quite a bit heavier). Not sure the height thing is necessarily true here as I've found that Calgary's Siemens S200 = 3.85m (though looks like they are shorter for other cities) and the Urbos 100 = 3.65m. I'm sure there's a little more nuance there, but the weight thing seems like a more substantial difference.
whatchyyc
Active Member
Seems like he got the S200 weight from the minimum spec listed on Wikipedia, probably for the SF MUNI version. Siemens spec sheet lists ours at 40,800kg. Most 7 segment Urbos 100 trains are about 53,000kg, but I remember that the city said the 12 ton mockup represented about 20% of the final vehicle weight. Ours could be heavier because they'll have solid axles, but even at 60,000kg a 42m Urbos would be 1.5 times as heavy as an S200 while being 1.6 times longer
Infrastructurist
New Member
This is completely unrelated, but I've heard the new trains they have for the green line are actually about 2x as long as the current S200's does anyone know if this correlates directly with them having 2x the capacity? Also this is great video, integrating with the old via rail station is actually a really cool idea. I also found this old news report recently that shows an underground ctrain tunnel built ages ago. I wonder why this hasn't been used.
Edit: 1 google search and I answered my own question lol. Urbos 100 has a max of 288 passengers, S200 currently has a max of ~180
whatchyyc
Active Member
The capacity is slightly less for the length. Each car being longer leaves less interior space lost to cabs and couplers, but the low floor layout takes some away so it nearly evens out
InfrastructureEnthusiast
Active Member
Well, username checks out! Lol
But yeah, transit connected airports are another thing that says 'smart city'. Far more than a tunnel for the sake of a tunnel..
Care to point out where I was promoting such a thing? Avoiding surface entanglements can be done either above or below. Turns out that one is not only significantly cheaper than the other, but it also has a strong visual presence that showcases its speed and efficiency rather than hiding it at great expense.
Cute name
