Regional Rail (RUR) & North-South Rail Link (NSRL)

[DBM]

Re: North-South Rail Link

There is NO difference in flood protection between alignments. Portals are exactly the same places they were before because there's only discrete places they can possibly slot...like for example the NEC portal which has to be between Shawmut and Harrison centered on the Washington block because west is the Orange Line tunnel and east is the giant mass of switches for surface Cove Interlocking. Portals will have to have flood doors and active pumping, but down below has no potential for water intrusions.

Thoughtful debunking/skeptical analysis here, F-Line [and I would've expected no less]. I just want to point out, though, on the rising sea level consideration, which is what I immediately intuited as the possible key criteria: since the original Downtown shoreline pretty accurately corresponds to the Congress St. corridor, the fact is that the west side of Congress St. is the original geological strata, whereas the east side is landfill. So leaving aside the portals, what about the question of the porosity/permeability of the landfill strata vs. the original Shawmut peninsula composition? Apparently you're saying that's a non-starter?

 

[CSTH]

Re: North-South Rail Link

Reposting these from the summer:

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[F-Line to Dudley]

Re: North-South Rail Link

Thoughtful debunking/skeptical analysis here, F-Line [and I would've expected no less]. I just want to point out, though, on the rising sea level consideration, which is what I immediately intuited as the possible key criteria: since the original Downtown shoreline pretty accurately corresponds to the Congress St. corridor, the fact is that the west side of Congress St. is the original geological strata, whereas the east side is landfill. So leaving aside the portals, what about the question of the porosity/permeability of the landfill strata vs. the original Shawmut peninsula composition? Apparently you're saying that's a non-starter?

The depth of the tunnel is below the ancestral water level. The Big Dig breached the bottom of the man-made landfill (even to the point of finding a few 18th c. shipwrecks in the process). So in the same way that the lead tunnels for SS Under on the Dot Ave. alignment swing out underneath the Ft. Point Channel, if this was old Shawmut Peninsula the mainline would've been bored under the water. That's important in keeping it dry, because the hardest-hit areas on the flood map are in the poor drainage of the man-made landfill. In three dimensions, the CA/T NSRL alignment is below the landfill.

Moreover, it's already framed by the CA/T slurry walls and an extremely thick ceiling so water passing through the landfill up above is not going to leak downstairs. Also, I-93 upstairs gambled on bare slurry walls to get as wide a highway footprint as they could underneath the old Artery. That gamble came with a big downside of leak risk...and indeed the walls have leaked like a sieve for years. NSRL would not have that issue because its 2 tracks/2 bores occupy a far narrower footprint than the highway lanes above, meaning the existing slurry walls on that level would be finished off with a second water-tight layer of thick concrete. No possible intrusions from the landfill, no possible intrusions from the water table.

The only places where weapons-grade flood protection is needed (true for the CA/T or Congress alignments) are the portals. The NEC portal sits in an area of pretty terrifyingly high risk, and at shallow depth through landfill for about its first 2000 ft. Need big, strong flood doors there and any companion flood fortifications because the storm drain effect from that direction is basically Terror Threat #1 for the whole tunnel complex. Southampton portals...not quite as serious a risk, but similar fortifications required because steepness makes storm drain effect equally devastating. Northside portals are on a relative oasis on the flood map and are at much shallower depth...needs something, but not kitchen-sink strong like the 3 south portals.


Without knowing more about exactly how the Congress St. alignment is going to be constructed, it's anybody's guess which alignment performs relatively better on water intrusion risk in the mainline tunnel. But it's exactly the same risk for the portals, requiring exactly the same mitigation. Portal intrusions are a large (if easily mitigated) concern for the whole works on any alignment. Soil intrusion and street intrusion are microscopic in comparison to the portals/storm drain risk. All I can say is that if those microscopic risks are directly negated to pretty much zero in the CA/T alignment, it's hard to see how Congress could do any better.

 

[stefal]

Re: North-South Rail Link

Reposting these from the summer:

Should probably be posting this in Crazy Transit Pitches, but this alternative poses the potential for a sizeable public-private partnership redeveloping City Hall, CHP, and potentially JFK and Center Plaza, with a large supertransit stop spanning under the plaza, connecting Government Center, State/Haymarket (formerly "North Station Under"), Haymarket, and State. One could debate the need for such a station, but the opportunity to connect Government Center with State and Haymarket is there with this.

 

[F-Line to Dudley]

Re: North-South Rail Link

Should probably be posting this in Crazy Transit Pitches, but this alternative poses the potential for a sizeable public-private partnership redeveloping City Hall, CHP, and potentially JFK and Center Plaza, with a large supertransit stop spanning under the plaza, connecting Government Center, State/Haymarket (formerly "North Station Under"), Haymarket, and State. One could debate the need for such a station, but the opportunity to connect Government Center with State and Haymarket is there with this.

The picture says a thousand words. The secondary exit to NS Under on the CA/T alignment is literally across the street from Haymarket. How much effort would it take to drag the headhouse from the corner of Beverly St./N. Washington 450 ft. into the main Haymarket station? Problem already solved.

What kills this location dead? How about..."What's a North Station that doesn't provide access to North Station?" No connection whatsoever to the surface terminal is mortally disqualifying. Like a broken record...in an RER universe we are using the surface terminals to their fullest and fileting service upstairs/downstairs, meaning everyone is working their transfers to the hilt. WTF are we even building this thing for if you can't bloody transfer to one of our primary terminals??? Do you think the New Hampshire commuters running on diesel from Concord and Dover are going to appreciate having to take Green or Orange 1 stop to get on another Purple train to take them to their job on one of the southern 128 quadrants. Forget Crazy City Hall Pitches....Transitmatters needs to nuke this from orbit for again missing the point of what RER is.

 

[tysmith95]

Re: North-South Rail Link

So Seattle can build an 2 mile underground highway for 3 billion dollars (which is over budget btw), yet it costs mass 10 billion to build a shorter rail tunnel. Auto tunnels are usually larger (and therefore more expensive) than rail tunnels.

I am absolutely perplexed at why transit projects in this state are so expensive.

Even the 2nd Ave subway in NYC has a lower cost per mile then this.

 

[Arlington]

Re: North-South Rail Link

How about the sea level position of CS station entrances and emergency egress? ...

 

[CSTH]

Re: North-South Rail Link

How about the sea level position of CS station entrances and emergency egress? ...

Look I'm as alarmed as anyone by the sea level rise scenarios, but if your assumption is that it's not going to be possible to have underground infrastructure near the ocean then the question is 'where do we build the harbor closure dike?' not 'which nsrl alignment is going to be the smallest depth below the storm tide in 2050?'

 

[F-Line to Dudley]

Re: North-South Rail Link

How about the sea level position of CS station entrances and emergency egress? ...

If it's Aquarium, they're already planning fortifications for the Blue Line Resiliency study and CS will just piggyback onto that when it expands the headhouse.

Who knows what they're thinking with these alt alignments, because doesn't appear a whole lot of nitty-gritty thought has been put into them at all. Although, per previous posts, egress and soil intrusions are minor to nonexistent problems with the depths we're talking. Portal protection is what has always mattered, for any alignment.

 

[Arlington]

Re: North-South Rail Link

So Seattle can build an 2 mile underground highway for 3 billion dollars (which is over budget btw), yet it costs mass 10 billion to build a shorter rail tunnel. Auto tunnels are usually larger (and therefore more expensive) than rail tunnels.

I am absolutely perplexed at why transit projects in this state are so expensive.

Even the 2nd Ave subway in NYC has a lower cost per mile then this.

I think the $9B price tag, moreso than any alignment they chose (or didn't) tells you they were doing it wrong.

Even allowing for inflation (these are 2025 dollars or something) and allowing for having to excavate a cavern for a station (which Seattle did not), I just don't see how you get above $5b to $6b.

So one does come back to F-Line's point that they did not seem to have done careful engineering or transit planning, but somehow race right to picking the expensive-enough-to-kill-it scenario.

 

[Coyote137]

Re: North-South Rail Link

Charlie has future aspirations to consider, and being another big spender from MA won't help.

 

[boston85]

Re: North-South Rail Link

So Seattle can build an 2 mile underground highway for 3 billion dollars (which is over budget btw), yet it costs mass 10 billion to build a shorter rail tunnel. Auto tunnels are usually larger (and therefore more expensive) than rail tunnels.

I am absolutely perplexed at why transit projects in this state are so expensive.

Even the 2nd Ave subway in NYC has a lower cost per mile then this.

Dig into their cost estimate and you will see why. They took the entire cost of Seattle's project, which includes all the engineering, management, portal, roadways, risk contingencies and used that for their regression for cost per mile of tunnel boring and nothing else. After inflating the cost per bored tunnel to around $500M per mile then they add on factors for design, management, mitigation, stations, inflation, risks. I don't know about their other sources, but that Seattle reference is a blinding red flag as its a big outlier and is double counting.

Also to note, Seattle and a couple of the Russian projects used for references has the highest cost per mile(~$1B/mile), take those outliers out, and their regression significance goes to shit.

 

[Arlington]

Re: North-South Rail Link

Charlie has future aspirations to consider, and being another big spender from MA won't help.

Perfecto: Baker's core message has been "we can have this stuff, we just shouldn't overpay for it and don't need to raise taxes for it", which is a great Republican position in a role where (in the last presidential election) everyone agreed that there should be $1T spent on infrastructure.

So let's make this Baker's chance to reprise his GLX $3b --> $2b role by turning NSRL from $9b --> $6b.

 

[bigpicture7]

Re: North-South Rail Link

Perfecto: Baker's core message has been "we can have this stuff, we just shouldn't overpay for it and don't need to raise taxes for it", which is a great Republican position in a role where (in the last presidential election) everyone agreed that there should be $1T spent on infrastructure.

So let's make this Baker's chance to reprise his GLX $3b --> $2b role by turning NSRL from $9b --> $6b.

I think this is spot on. Baker needed a fake high number, so he can be the republican hero who swoops in and "lowers" it. Or, if the whole thing fails, he can just pin it on high cost that's "irresponsible" for the taxpayers. It's a win-win for him.

 

[fattony]

Re: North-South Rail Link

Ari wrote a whole post a while ago explaining why the current North Station and Central-under-Aquarium are lousy locations for a major train station. Pretty interesting read: http://amateurplanner.blogspot.com/2017/08/north-station-doesnt-belong-on-north.html

 

[bakgwailo]

Re: North-South Rail Link

I'm not saying it makes sense, but suspect you'll get a list like this:

• Shorter, straighter routing
• Closer to tallest buildings & "the center"
• Central Station connected to Green, Orange, Blue
• Farther from the rising ocean.
• Option to build 2 now and 2 later

I'm not saying that I know that these advantages outweigh those of tunneling through the Big Dig's clean fill, but they are the advantages of a Congress St alignment. The real question is how they scored these and priced out the tunneling costs.

This would also leave the ROW under 93 free - which might make subway usage (which I think has been discussed in crazy pitches) a possibility at some point. I do agree that I think it would be short sighted to not do 4 tracks now - or at least really future proof it to make adding two more track trivial when need arises.

 

[F-Line to Dudley]

Re: North-South Rail Link

Ari wrote a whole post a while ago explaining why the current North Station and Central-under-Aquarium are lousy locations for a major train station. Pretty interesting read: http://amateurplanner.blogspot.com/2017/08/north-station-doesnt-belong-on-north.html

It's interesting, but wrong. He completely omits the fact that the secondary NS entrance on the CA/T alignment is so extremely close to Haymarket that it can/will be integrated into that station. That fact kicks the legs out from under his whole "off-roading" alignment in same way this Congress St. alignment doesn't add up. His whole stance only holds water with willful omission of that fact.


I love Ari's work, but that was a sloppily researched and somewhat disingenuously argued post by his standards.

 

[fattony]

Re: North-South Rail Link

So which northside lines will use the link under this proposal? Clearly half the southside lines will continue to terminate all trains at SS.

 

[tangent]

Re: North-South Rail Link

The other part of this is that the quick blurb the press uses to describe the project is completely wrong. The existing North and South "Stations" can't be "connected" by NSRL. That is a physical impossibility in any real meaningful sense since the portals will be well north and south of the stations and the underground platforms would be quite a walk away from the existing station platforms.

It is the North and South rail networks that would be connected. Saying they would be connecting the stations themselves is an artificial political constraint which appears to just add costs by trying to locate the new underground platforms as close as possible so they could be connected somehow underground with walkways to the existing North and South stations.

 

[Arlington]

Re: North-South Rail Link

So which northside lines will use the link under this proposal? Clearly half the southside lines will continue to terminate all trains at SS.

As I read it, all Northside lines get connected to the NSRL, via either (1) Fitchburg portal or the (2) Portal for everything else. The Northside doesn't have the geometric complications that the Southside has (that make doing the Old Colony & Fairmont hard)

Then it is a very different question of which particular trains go into/through North Station Under versus which terminate at North Station (surface), which is all TBD.