Tunnels!

Roads - Rails - Sidewalks - Bikeways
talindsay
Wells Fargo Center
Posts: 1537
Joined: September 29th, 2012, 10:41 am

Re: Tunnels!

Postby talindsay » January 4th, 2021, 11:51 am

Back in 2003 I asked a Met Council person why they hadn't considered elevating the (Hiawatha) line through downtown to remove grade conflict and the dude laughed dismissively, saying it would interfere with the skyways. That seemed like an unsatisfactory response to me, but Metro Council has clearly never taken elevated lines in the downtown seriously. And to be fair, they *are* ugly and disruptive, and the skyway problem is real.

I've also heard that our tunneling costs are relatively low compared to most places, and so the cost difference between elevating and tunneling is smaller than in most places. Basically if it's not worth tunneling here, it's not worth elevating either given the small difference in cost and the substantially higher disruption and environmental impact of elevated rail.

DanPatchToget
Foshay Tower
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Joined: March 30th, 2016, 1:26 pm

Re: Tunnels!

Postby DanPatchToget » January 4th, 2021, 12:02 pm

While Miami doesn't have skyways (that I know of) their Metro Rail is elevated above their People Mover system in downtown, so that's probably the closest example of what elevated rail in Downtown Minneapolis would look like. I don't think anyone is proposing building the tracks through the skyways and then we have to deal with many grade crossings in skyways, but rather have the tracks go above the skyways.

Tcmetro
Wells Fargo Center
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Joined: May 31st, 2012, 8:02 pm
Location: Chicago (ex-Minneapolitan)

Re: Tunnels!

Postby Tcmetro » January 4th, 2021, 12:40 pm

I think the downtown at-grade alignment is fine. Considering there's no long-term plan to add a third line to the 5th St corridor there isn't much need. I'd even be surprised if 7.5 min peak frequencies come back before the next decade.

As for the cheap tunneling, I believe it was first considered in the late 60s. The idea is that limestone is relatively easy to dig through. The problem is that the limestone layer is like 80 feet below ground, so stations would be quite expensive to build. The initial subway plan had stop spacing of 1-3 miles.

DanPatchToget
Foshay Tower
Posts: 849
Joined: March 30th, 2016, 1:26 pm

Re: Tunnels!

Postby DanPatchToget » January 4th, 2021, 2:26 pm

I think the downtown at-grade alignment is fine. Considering there's no long-term plan to add a third line to the 5th St corridor there isn't much need. I'd even be surprised if 7.5 min peak frequencies come back before the next decade.

As for the cheap tunneling, I believe it was first considered in the late 60s. The idea is that limestone is relatively easy to dig through. The problem is that the limestone layer is like 80 feet below ground, so stations would be quite expensive to build. The initial subway plan had stop spacing of 1-3 miles.
From a near term perspective yes the 5th Street Corridor does the job. Long term however, I don't think it's in our best interest to rely on a corridor that's already at capacity.

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Nick
Capella Tower
Posts: 2716
Joined: May 30th, 2012, 9:33 pm
Location: Loring Park, Minneapolis

Re: Tunnels!

Postby Nick » January 6th, 2021, 10:57 pm

Man, does anybody remember the argument on here like six or seven years ago about whether or not train frequencies would increase on 5th Street with the Blue and Green Line extensions?

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Anondson
IDS Center
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Joined: July 21st, 2013, 8:57 pm
Location: Where West Minneapolis Once Was

Re: Tunnels!

Postby Anondson » January 7th, 2021, 3:47 pm

All the time.

Tom H.
Rice Park
Posts: 433
Joined: September 4th, 2012, 5:23 am

Re: Tunnels!

Postby Tom H. » January 10th, 2021, 1:46 pm

Vividly.


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