Quote:
Originally Posted by trofirhen
THE CANADA LINE cannot go under the harbour, as C.M. said. It's too shallow, it seems, and it would have to make a sharp L - turn to go sideways to gain depth.
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Just rebuild the tail tracks north of Waterfront station, and the whole crossing should be doable within 6% grade using cut and cover and immersed tube. I don't know what's the maximum grade those Rotem trains can handle, but the industry standard seems to be around 7-8% with some companies offer up to 14%. So the worse case would be just getting some new trains that can handle steeper grade.
Distance between the edge of platform and Expo line track is ~80m, so with a rebuilt tail tracks, the line can drop 5m before reaching Expo Line at 6% grade. If this is problematic, I'm sure the train can handle a drop of ~8% at a short distance.. (What's the grade for the tunnel portal near Marine Drive? It seems more than 6% to me)
Distance between the edge of platform and the edge of water is ~180m, so the line would be already 11m underground with 6% grade.
The length of the harbour is 3400m and the maximum depth is 75m. With immersed tube, you don't need to dig deep into the soil. You either place the tube on the ocean floor and cover it with soil and rocks, or cut a small trench and place the tube inside the trench. So the tunnel only need to go down at most 80m at its deepest. Assume the tunnel enters the water at 10m below ground on Vancouver end and 5m on North Van end, only 4.3% average grade is required for the crossing.
The main problem with that proposal is that the feasibility of the harbour crossing, but it is how the line run up Lonsdale Ave. Assuming the line come aground 5m below surface, and run at 6% grade between each station:
Scenario 1:
Station 1 at Lonsdale and Eplanade: -10m
Station 2 at Lonsdale and 13th: -40m (Compare this to 25m for Granville)
Station 3 at Lonsdale and 23rd: +0m
Scenario 2:
Station 1 at Lonsdale and Eplanade: -10m
Station 2 at Lonsdale and Keith: -40m
Station 3 at Lonsdale and 20th: -20m
Station 4 at Lonsdale and 29th: -25m
The first scenario can barely made it up the hill with one very deep station (probably the access is going to be elevator-only). The second scenario just not feasible.
So this is my funny-looking proposal for the North Van line:
(Brown = cut and cover tunnel, Blue = elevated, Red = bored tunnel)
It would be a longer, 9.9km route from Lynn Valley, with 3 elevated and 3 underground stations:
Station 1 at Lonsdale Quay: -5m
Station 2 at Forbes and 3rd (E/W line): +5m (4% grade)
Station 3 at North Van City Hall: -10m (6% grade)
Station 4 at Lonsdale and 20th: -5m (5% grade)
Station 5 at Lynn Valley and TCH: +5m (3% grade)
Station 6 at Lynn Valley and 29th: +5m (pretty much flat)
This way it would avoid those very deep station when going up Lonsdale, although the screeching noise would probably going to be quite annoying...