M II A II R II K
Senior Member
So it’s likely to be above ground west of Bathurst and would be more useful north of the Gardiner, but will the Liberty Villagers object to having it cut through neighbourhoods.
If the Liberals before, or David Miller, or City Council when they took the transit file away from Ford, actually prioritized the DRL - then the station design would have been known.
I suspect the Province is eyeing something like #1 (red). Queen to Bathurst to Front under Fort York to station at CNE streetcar loop.
An alternative I could conceive of is #2 (orange). Quuen to Strachan to Fleet to Princes' to station near BMO Field.
The desire to not cut transit lines under building would preclude a lot of other choices.
View attachment 181406
One of a number of examinations of the plan. Again, the reference is to what was to be the *City's DRL plan*. It was to only cross the Don at one point!
They can, but then the design of the TBM is highly compromised when doing much longer sections. To do the curves people are asking about means the TBMs themselves would have to be articulated in length of sections no longer than the cars planned for tunnel, and that presents immense problems. In practical terms, really tight turns would have to be bored manually, or by a machine or shield dropped down a vertical shaft at that point, which raises costs dramatically. This brings us back to @BurlOak 's continual point on modern cut and cover techniques, and how deep the tunnelling would be at certain points and if C&C would be more apt in those sections. It's apt you ask, because the TTC's alignment as published shows very sharp curves at points, ones that I intuitively guessed would be very difficult for TBMs to do. These problematic sharp turns are rampant in Ford's Fantasy Foible.Is a tunnel boring machine capable of making such tight turns?
http://www.cat-bus.com/2018/01/far-from-boringmeet-the-most-interesting-tunnel-boring-machines/[...]
People tend to think it’s the tunnels that are the most expensive part of underground systems like metros, but thanks to the already existing TBM technology, they often represent only a small portion of the overall cost. Sometimes as little as 10%
[....]
A large diameter tunnel becomes really interesting for the construction of a metro, if it is large enough to fit not only the tracks, but the station platforms inside it. This saves costs because it’s unnecessary to excavate large caverns, possibly dug from above requiring the purchase of a large amount of land. [...]
The cost of a TBM doesn’t get much higher as you increase its diameter. Tt is therefore cheaper to build one very large tunnel, rather than two smaller ones. So giant, linear tunnel building factories have been constructed, with some reaching up to 17.6m in diameter.
[...]
The issue is that for the "bridge" that was part of the TTC's planned Don Crossing is that the Don would be only crossed at one point.(By Eastern Ave) And the TTC had finalized and published their route for the DRL for all but a few small details. And it was the TTC's DRL (South) that Ford was referring to. The Relief Line North is and was always a Metronlinx project. Even DRL South was shared with the TTC when it became obvious that the TTC (and later City) were in over their bore depth.The issue we dont how much of RLN was planned.
The space age maglev system immediately won the interest of the Davis government, and in the Phase II proposals they selected it for further study, along with the Ford ACT and Hawker Siddeley's entry, both of which used rubber tires. Ford withdrew when the ICTS varied too greatly from the system it wanted to develop, which was aimed primarily at sites in the U.S. With only Hawker Siddeley and Krauss-Maffei remaining, the 1 May 1973 announcement that the Krauss-Maffei design had won the contest was unsurprising.
In November 1974 Krauss-Maffei announced that it was forced to withdraw from the project. The West German government had been funding development of several maglev systems based on different technologies, and decided at that time that Krauss-Maffei's system was less interesting than ones from Thyssen-Henschel and Messerschmitt-Bölkow-Blohm. There were also technical problems; in testing, the complex systems needed to switch trains on the magnetic tracks froze up, and would require a re-design. With Krauss-Maffei's financial support gone, and daunting technical problems remaining to be solved, the maglev project died. A test track being constructed on the grounds of the Canadian National Exhibition was abandoned in place, with the foundations and a few support pillars already constructed. Krauss-Maffei continued development of the original inter-city Transrapid, but at a very slow pace and through a series of mergers with other companies involved in maglev technology. The first Transrapid system did not enter service until 30 years later.
If I understand this right, curves of radius above 300m can likely be bored. I was imagining a radius of about 100m (something that TTC subways can't handle, but these REM type trains can). Do they basically dig up the curve from above and built it cut and cover? The TBM then passes through this and continues on it's way on a tangent. It's work from above, but it's still faster than a station because it's just the tunnel that's poured and the rest just back-filled. The TBM also doesn't need to be dismantled to cross this space.They can, but then the design of the TBM is highly compromised when doing much longer sections. To do the curves people are asking about means the TBMs themselves would have to be articulated in length of sections no longer than the cars planned for tunnel, and that presents immense problems. In practical terms, really tight turns would have to be bored manually, or by a machine or shield dropped down a vertical shaft at that point, which raises costs dramatically. This brings us back to @BurlOak 's continual point on modern cut and cover techniques, and how deep the tunnelling would be at certain points and if C&C would be more apt in those sections. It's apt you ask, because the TTC's alignment as published shows very sharp curves at points, ones that I intuitively guessed would be very difficult for TBMs to do. These problematic sharp turns are rampant in Ford's Fantasy Foible.
I see a number of very good TBMs engineering papers on-line, I'll read a few more before referencing.
Edit to Add: Catbus to the rescue yet again, and very germane to this discussion as the REM is his main muse:
http://www.cat-bus.com/2018/01/far-from-boringmeet-the-most-interesting-tunnel-boring-machines/
As with the bridge controversy, one of the points remains the same: Once you have TBMs at work deep tunnelling, you keep them at that level unless you have a very real need to surface them, like a portal at the end of the underground section, not bringing them all the way up to cross a bridge to go all the way down again. For a deep river valley as you find on the northern leg, your bore depth in the surrounding area is not as deep as the valley floor you're going to traverse, so you *emerge* at near neutral grade to cross that valley, and in the case of the Leaside area crossing, the track would be run on embankment to allow level grade crossing for the various bridges needed to cross the DVP, Bayview, Bala Sub and Don River bridges before boring into the northern face of the valley to continue north.
The issue is that for the "bridge" that was part of the TTC's planned Don Crossing is that the Don would be only crossed at one point.(By Eastern Ave) And the TTC had finalized and published their route for the DRL for all but a few small details. And it was the TTC's DRL (South) that Ford was referring to. The Relief Line North is and was always a Metronlinx project. Even DRL South was shared with the TTC when it became obvious that the TTC (and later City) were in over their bore depth.
Well here's where the mined muck hits the belt:If I understand this right, curves of radius above 300m can likely be bored. I was imagining a radius of about 100m (something that TTC subways can't handle, but these REM type trains can).
[...]Urban EPB Tunneling in Limited Space:
A Case Study of the San Francisco Central Subway Project
Noah Johnson
The Robbins Company
ABSTRACT: The San Francisco Central Subway project is a challenging modern example of urban tunneling in limited space conditions. Two 6.3 m diameter Earth Pressure Balance Machines (EPBs) are excavating parallel 2.5 km long tunnels under low cover and in mixed ground conditions. The small launch site situated between an interstate and an off-ramp, highly curved tunnel alignment, and geology are particular challenges. These elements required customized tunnel and machine design, from TBM shipment and assembly, to launch and excavation. This paper discusses the project challenges and solutions at the Central Subway project, with a focus on TBM and continuous conveyor logistics. Requirements of the project include explosion-proof electrical components, laser-guided survey, rubber-tired supply vehicles, and machine and back-up solutions for steep inclines and tight curves.
http://www.therobbinscompany.com/wp-content/uploads/2014/08/UrbanEPBs_NAT2014.pdf[...]The tunnels will level out then take a sharp right turn (R 137 m) towards the north at Market Street, where they will pass under two other operational subway lines. In order to ensure the safety of those lines during boring operations, a liquid level system working in concert with longitudinal and transverse strain gauges and other instrumentation will be used to monitor ground disruption. The system will be used under the live tracks and determine if settlement mitigation measures must be executed
[...]
Due to the complex geometry of the alignment, steering the TBMs accurately through the tight curves (min R 137 m) is one of the key challenges of the project. To accomplish this it was necessary to articulate the TBM shields. An active articulation system was integrated as it allows the thrust cylinders to remain parallel to the tail skin and react evenly with the segments. This feature mitigates the risk of segment damage, ring deformation, or settlement during boring.
[...]
It's more a question of where to dump it than the extraction itself. For Crossrail, it was shipped by freight from within the tunnels to the mouth of the Thames some thirty miles away to create new islands in the estuary as wildlife sanctuaries. That's yet another advantage of boring to mainline standards.The other thing, as I understand it, is that taking the muck out of the shaft becomes harder as it becomes longer.
It sure wouldn't.In terms of cut-and-cover, I worry it might not fly downtown.
Tunnelling
Sydney’s new metro railway will run through purpose designed and built tunnels.
A number of factors determine the tunnel route and alignment. These include:
Stage 1: Sydney Metro Northwest
- the location, depth and structure of the stations
- vertical track grade
- rock conditions
- track curvature, to allow train speeds of up to 100 kilometres an hour
- the physical constraints of the route, including crossing under Sydney Harbour.
Tunnelling finished in January 2016 on Australia’s longest railway tunnels – twin 15 kilometre tunnels from Bella Vista to Epping as part of Stage 1 of Sydney Metro.
Stage 2: Sydney Metro City & Southwest
Tunnelling started in October, 2018 on the twin tunnels from Chatswood to Sydenham, including under Sydney Harbour and through the Sydney CBD.
Tunnel boring machine progress
[...Google maps and interactive panes...]
The most successful transit systems in the world are more real-estate development initiatives than transport initiatives (though they combine both.) In Japan and Hong Kong, the agency planning the transit owns the station lands and gets developers to build apartment/mall/office complexes on top of where the stations will go. The transit agency reaps both the ridership and the rents.
...
The most successful transit systems in the world are more real-estate development initiatives than transport initiatives (though they combine both.) In Japan and Hong Kong, the agency planning the transit owns the station lands and gets developers to build apartment/mall/office complexes on top of where the stations will go. The transit agency reaps both the ridership and the rents.
...
It's redundancy. Also, some on LSE, who are going to City Hall, may want to make the transfer here - it would relieve Union a bit. A similar argument could be made that having an Ontario Line station on the other rail corridor may have some benefit.I dont understand the obsession with this line intersecting with the existing GO?Smarttrack stations? Exhibition/Liberty GO.
I think it really doesnt offer much benefit in terms of inter-modality. I dont think many people wish to transfer to these stations, when they could just take the trains from these to Union already. They basically go to the same place.
Id rather see a stop in the heart of Liberty, at the parking lot of Atlantic/East Liberty, and a stop right at Ontario Place.
I dont understand the obsession with this line intersecting with the existing GO?Smarttrack stations? Exhibition/Liberty GO.
I think it really doesnt offer much benefit in terms of inter-modality. I dont think many people wish to transfer to these stations, when they could just take the trains from these to Union already. They basically go to the same place.
Id rather see a stop in the heart of Liberty, at the parking lot of Atlantic/East Liberty, and a stop right at Ontario Place.