Red Line / Blue Line Connector

F-Line to Dudley

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Yes. GC Emergency Exit is located here.(https://goo.gl/maps/UJmRi6bUZasZRX7B6). Entrances on the "Bowdoinside" of both MGH and GC are a better solution than keeping a curve-crippled Bowdoin. And if we're crazy-wrong, in 40 years, you can come back and do an infill on its site. When they straighten things out and eliminate Bowdoin they should put it in a place that doesn't rule out a Future Straight Bowdoin.

Depending on what AFC 2.0 looks like, you could probably push the front doors /canopy to the headhouse another 50 feet closer to Bowdoin/Sudbury/Bullfinch Place for a psychological win.

And, yes, build/provision MGH Blue as a two-ended platform
One of the reasons they didn't attempt a 6-car lengthening of Bowdoin is that the structural mods would've ended up dragging it even closer to GC where the emergency exit conversion beckons. As it stands a substantial portion of Bowdoin's platform would remain structurally intact when they do the partial demo for the loop-end straightening, leaving it and a recycled rump of the exit staircase as a level-boarding emergency exit for 3-4 cars. Yes, you'd absolutely be able to build a new station there by recycling the easterly platform remainder and extending it anew to one side or the other. But that'll either put you true-uselessly close to GC...on the order of 300-400 ft....if it stretches east, or pretty redundantly close to Charles if the new platform extension trudges further west. Charles itself has the option for an easterly Blue-only headhouse on the Grove-Anderson Sts. block if funding allows, and that kicks another leg out from under Bowdoin. Because then if you opt to rebuild it post-straightening the works are going to shift further west, entrance-to-entrance on that side is 1000-1200 ft.

I wouldn't hand-wring about Bowdoin. You can do the partial demo and attempt some sort of rebuild later if demand does hedge towards closer stop spacing. But you won't ever get a chance to buy longer, higher-capacity cars without straightening through the loop. You won't get a minimum operable headway that can match Orange or Red's capabilities unless you whack the speed restriction near the loop structure. And outward expansion north to Lynn & beyond or west to Kenmore & beyond is going to be harder to administer unless you even up the asynchronous IB vs. OB speeds through the loop structure. Those considerations are all saddled with complications forever if you don't demo Bowdoin. You're never--for life--prevented from building a new Bowdoin if need be after some healthy debate about whether it's truly necessary points to the affirmative.

Ergo, smash that loop to bits and don't worry about the rest until you've got funding, because all 100-year considerations are covered any which way.
 

ulrichomega

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F-Line, isn't there a similar restriction on Blue Line car size from one of the curves on State Street? I have vague recollections of you talking about that in the past.

And my understanding is also that you can't reuse any of the Bowdoin platforms, at least under some of the plans for construction, because the plan is to tunnel under them to go out along Cambridge St. That's why I was talking about construction of a newer station a bit further from GC once the grade levels off. See: https://www.mass.gov/files/documents/2018/10/19/SummMem_ConstStudy_0.pdf

However, looking at that study, it appears any sort of Bowdoin station is actually, literally impossible. The grade doesn't level off until well past Staniford, at which point you're basically constructing a new station right on top of the Charles switches. I suppose you could argue for attempting to put a lot of the grade change after a Bowdoin station (which seems like it would also minimize the amount of excavation), but that doesn't appear to be in the cards. I'm aware that the grades I'm looking at are for the old study, but I haven't found anything to suggest not doing something basically the same with the new alternatives.
 
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Suffolk 83

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I'm sure this has been mentioned but wouldnt the easiest albeit not most superior option would be to build a pedestrian tunnel from DTX to State st? Wouldn't this at least make do?
 

JeffDowntown

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I'm sure this has been mentioned but wouldnt the easiest albeit not most superior option would be to build a pedestrian tunnel from DTX to State st? Wouldn't this at least make do?
The super station tunnel (connecting OL Forest Hills at State to OL Oak Grove at DTC) certainly should be built. But for any volume of Red to Blue connectivity that is a really poor connection. By T standards, it is already an inconvenient haul from BL to OL Forest Hills. Connecting through the busy platforms all the way from BL to RL is not going to be very attractive.

It also does not actually relieve the pedestrian traffic volume in those stations, which is a throughput choke point. People fighting their way from BL to RL via the packed OL platforms is not going to speed up operations.

Which is why the system really needs a separate connection point (clear of the overstressed downtown transfer stations) for BL to RL.
 

Arlington

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I'm sure this has been mentioned but wouldnt the easiest albeit not most superior option would be to build a pedestrian tunnel from DTX to State st? Wouldn't this at least make do?
Now's not the time to accept inferior (and lesser-studied) alternatives. Red Blue @ MGH
- Is on its way to "shovel ready"
- Serves high walkable demand at MGH/Beacon Hill
- Relieves the Red and loads Blue where it has slack capacity
- Is an easy up/down connection
- sets up future Blue enhancements

Beyond that, I think the next most sensible tunneling Downtown would be the NSRL
 

F-Line to Dudley

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F-Line, isn't there a similar restriction on Blue Line car size from one of the curves on State Street? I have vague recollections of you talking about that in the past.

And my understanding is also that you can't reuse any of the Bowdoin platforms, at least under some of the plans for construction, because the plan is to tunnel under them to go out along Cambridge St. That's why I was talking about construction of a newer station a bit further from GC once the grade levels off. See: https://www.mass.gov/files/documents/2018/10/19/SummMem_ConstStudy_0.pdf

However, looking at that study, it appears any sort of Bowdoin station is actually, literally impossible. The grade doesn't level off until well past Staniford, at which point you're basically constructing a new station right on top of the Charles switches. I suppose you could argue for attempting to put a lot of the grade change after a Bowdoin station (which seems like it would also minimize the amount of excavation), but that doesn't appear to be in the cards. I'm aware that the grades I'm looking at are for the old study, but I haven't found anything to suggest not doing something basically the same with the new alternatives.
State is not the ruling curve...Bowdoin is. So retention of the loop and the half-loop for thru service locks Blue in at the current car size. State is a MUCH less severe curve, so the cars you would be able to order in the very next procurement would be able to be considerably longer with Red-Blue constructed with the Bowdoin alignment straightening. The burning question is whether you'd be able to re-standardize the carbodies at rote Orange dimensions (note: the slight difference in platform heights Blue vs. Orange is accommodated in the adjustable air ballast in the cars and does not require any design differences). I've never been able to find an official quote on both the Orange Line's ruling curve and State curve's radius so that answer isn't verifiable without getting very lucky on Google. But State is close enough to Orange specs that demoing Bowdoin for Red-Blue either allows you a very nearly Orange-length car with only slight stubbiness...or a "Blue Line Transformation" studies the costs of a State curve-easing and sees if the difference can be made up. At any rate, eliminating Bowdoin as the ruling curve is easily worth 50+ seats per 6-car train for however much longer cars they want to buy for the 0800 series, and that is going to loom large if Suffolk Downs redev and/or Lynn exert their influence on ridership.

More consequential, however, is whacking that speed restriction. You simply can't get the headways down in the neighborhood of what Red and (ultimately) Orange are capable of if the inbound trip to Charles on the half-loop is so extremely slower than the outbound trip from Charles that only has to pass through the far straighter end of the loop. It's silly to get all that precious about Bowdoin station and footsteps-counts from the next-nearest stop when aggregate accessibility is a whole lot worse on a line that could in the future saturate at 6-min. headways and has no way to drop to 5/4/3-mins. because we hand-wrung ourselves into a corner about touching that one misfit station's platform.

As for whether it's rebuildable...yes, that depends on what set of blueprints you're looking at. Originally it was assumed to be cut-and-cover, and at cut-and-cover the rump-of-Bowdoin emergency exit plan with open door for rebuilding was in effect. Then the state said...no, it must be deep-bore. Then there was all the expert push-back saying...no, there's nothing wrong with cut-and-cover except you wanting to tank the project. Then, instead of saying "No, we know what we're talking about" re: the deep-bore plan, this recent backpedalling opening up the door for cut-and-cover again. So we don't know anything for sure, except that there was probably no small amount of thuthiness in the state's last presentation if they were so quick to backpedal. All you can say is that the possibility of a reanimated Bowdoin is nonzero, and we'll know a bit more when this next study takes an engineering crack at it. But again...something is amiss if Bowdoin's fate is keeping anyone up at night. If it's a choice between 50-year capacity gains for the whole line present configuration AND extended each direction, and fear of what a future-redevved Bulfinch Triangle will generate for ridership...what is the higher-leverage proposition? Is it the never-major 'tweener stop taking the same 210-seat cars at middling headways forever, or dual-headhoused GC & Charles being able to take 270-seat cars at as little as 3 minutes a pop when saturation finally requires those headways. This is a pointless one to "yeah, but..." because raw throughput is going to slay the footstep count on-balance (in a way, because of the low-use/'tweener status, that you wouldn't be able to project with this much more controversial "Master Station" consolidation at the downtown transfers). Build Red-Blue for the throughput, hope for sanity and transparency in the study...and if the study ends up matching with the previous C&C scenarios that kept the Bowdoin emergency exit rump know that then there'll at least be the realistic possibility to re-infill if necessary.
 

FK4

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The psychology is very important here — you can get away with much greater distances if your connection is an underground passage — the reason it works in London etc is it just feels like a lot less of a distance when you’re walking underground.. since underground connections are often cumbersome anyway, like the SB OL to SB RL at DTX. I’m not advocating anything specific here, just saying that if you walk on the sidewalk it can seem twice as long.

This is relevant for future projects, as well, as we discussed on the GL expansion thread with a proposal for a large underground series of stations that all would technically be called Tufts Med.
 

mass88

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Where would you rank the importance/benefit of the red/blue connector among other transit related projects either under construction or proposed?
 

DominusNovus

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The psychology is very important here — you can get away with much greater distances if your connection is an underground passage — the reason it works in London etc is it just feels like a lot less of a distance when you’re walking underground.. since underground connections are often cumbersome anyway, like the SB OL to SB RL at DTX. I’m not advocating anything specific here, just saying that if you walk on the sidewalk it can seem twice as long.

This is relevant for future projects, as well, as we discussed on the GL expansion thread with a proposal for a large underground series of stations that all would technically be called Tufts Med.
i wouldn’t say its just psychology - you can get away with further distances because those tunnels are strictly segregated for pedestrian traffic between stations. Everyone can walk further and quicker because nobody has to wait for the walk signal while crossing streets and the flow of pedestrian traffic is pretty uniform on terms of speed (few are casually strolling) and direction (the trains themselves sort out the clumps).
 

jklo

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Where would you rank the importance/benefit of the red/blue connector among other transit related projects either under construction or proposed?
In terms of projects that are realistic, rather high. Mostly due to making connectivity to/from Kendall much easier. Kendall is what makes it worthwhile doing.
 

Arlington

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I would rate this below the "Transformation" (signals, rolling stock, geometry) and maybe below an infill like Assembly, but above any extension (GLX, BLX Lynn, OLX Southwest)

This got demoted more because support was diffused across the system vs GLX got done because support was locally adamant.
 

George_Apley

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I would rate this below the "Transformation" (signals, rolling stock, geometry) and maybe below an infill like Assembly, but above any extension (GLX, BLX Lynn, OLX Southwest)

This got demoted more because support was diffused across the system vs GLX got done because support was locally adamant.
Yes. The reason it's being resurrected now is that there's a massive coalition for transit improvements from the business community. Corporate Boston is rightfully fearful of what continued gridlock means for the future of the city's prosperity.

Plus transit advocates (led by TransitMatters) are far more organized than at any time in the last half-century.
 

bakgwailo

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Yes. The reason it's being resurrected now is that there's a massive coalition for transit improvements from the business community. Corporate Boston is rightfully fearful of what continued gridlock means for the future of the city's prosperity.

Plus transit advocates (led by TransitMatters) are far more organized than at any time in the last half-century.
The State also kind of shot itself in the foot in the Amazon bid.
 

whighlander

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Yes. The reason it's being resurrected now is that there's a massive coalition for transit improvements from the business community. Corporate Boston is rightfully fearful of what continued gridlock means for the future of the city's prosperity.

Plus transit advocates (led by TransitMatters) are far more organized than at any time in the last half-century.
I think its the realization of the need for redundancy to insure a state of adequate service -- all of the recent major T failures [going back to the Snowpocalypse] highlight the number of places in the system where single point failures can cause systemic failures

If you connect Red - Blue @ Charles*1 you can isolate a lot of failures and provide redundant routing without getting out the buses. Of course a good connection from Somewhere west of Kenmore to somewhere near Kendall and then North Station would really help

Redundancy is one of key features of the Tube in London -- they have lots of individual failures [stations closed, lines closed] but because of their massive amounts of redundancy they can Keep Calm and Carry On as the Brits say

Of course before the Red-Blue @ Charles -- I think a priority is a Red-Blue via Orange using a pedestrian tunnel from DTX to State either along the Washington St Subway ROW -- this can enable a single entrance to serve as a portal to Red, Green, Blue, orange and SL to Dudley

*1 -- I would continue the Blue Line past MGH along the Esplanade then under the Charles to a new Kendall West and then on to Lechemere -- using tunnel boring machine
 

Charlie_mta

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For the short stretch from Bowdoin to Charles, mobilizing a tunnel boring machine for that would be very expensive. I'd say do the cut-and-cover and call it good. The street is wide so the surface traffic could be routed through with a bit of lane reduction temporarily.

It's not just system redundancy that this link would provide. It would take quite a bit of traffic off the Green Line pinch point between Park Street and GC, and obviously reduce the changeovers to Logan from the Red Line (via the Blue Line).
 

KriterionBOS

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Is this RL-BL connector still just a proposal or is it under construction already?
 

whighlander

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For the short stretch from Bowdoin to Charles, mobilizing a tunnel boring machine for that would be very expensive. I'd say do the cut-and-cover and call it good. The street is wide so the surface traffic could be routed through with a bit of lane reduction temporarily.

It's not just system redundancy that this link would provide. It would take quite a bit of traffic off the Green Line pinch point between Park Street and GC, and obviously reduce the changeovers to Logan from the Red Line (via the Blue Line).
Charlie -- the TBM would be used from the Charles @ MGH Blue Line Station under Storrow Dr to the Storrow @ Mass Ave Station ["Just a handfull of Smoots from MIT"] under the Charles near the Mit/Harvard Bridge and then down Mass Ave and over to the Kendall West Station [essentially at Draper -- ultimately a Grand Junction to Blue Transfer Pt] on to a new underground Blue at Lechemere -

That should be enough work to justify a TBM
 

F-Line to Dudley

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Charlie -- the TBM would be used from the Charles @ MGH Blue Line Station under Storrow Dr to the Storrow @ Mass Ave Station ["Just a handfull of Smoots from MIT"] under the Charles near the Mit/Harvard Bridge and then down Mass Ave and over to the Kendall West Station [essentially at Draper -- ultimately a Grand Junction to Blue Transfer Pt] on to a new underground Blue at Lechemere -

That should be enough work to justify a TBM
No, tou wouldn't be TBM'ing under Storrow. Because that assumes you're saving all of Storrow at far greater expense. Blue-Kenmore only happens if you're tearing down the midsection of Storrow for a parkway diet.

You'd be open-air cuttting on Storrow's westbound carriageway at semi-surface level from the point where the Charles Circle ramps pull away, depth akin to the rump of Green Line tunnel behind the Hynes stop that sticks well above daylight at Pike level. It would essentially be rebuilding the Back St. retaining wall as a tunnel wall + passive flood barrier, with the ceiling capped 3-6 ft. above ground and covered with dirt landscaping. The 3-lane eastbound carriageway can stay as a low traffic Esplanade access road, and the landscaping over the new tunnel on the WB carriageway can basically be like a much longer "BU Beach" earthen berm. The tunnel would be situated a full 20-30 ft. shallower than cut-and-cover, because there is no utility sandwich layer under the Storrow pavement. And that's why it slays TBM'ing or any other means on cost-effectiveness. Think of it like a longer linear Wellington Orange Line tunnel that pokes its ceiling a little higher above-ground.

The tunneling economics do not work at all if they have to incur roadway rebuilding or preservation costs and use a more expensive boring method. You are not keeping Storrow while extending Blue...full-stop. Terms of engagement are that one has to go to enable the other. The project requires a local consensus that Storrow between the Kenmore and Public Gardens exits is a wholly redundant-to-Pike eyesore and induced demand trap that needs to be torn down, and by virtue of being torn down mandates a transit trade-in in the same project area capable of moving similar volume of people. (And by "in the same project area", I mean zero funds allowed for anything one may hope to do west of Kenmore because separate area from the Storrow footprint = separate project/separate timeframe.). Since that one chunk of the parkway IS wholly duplicated by the Pike on a segment of Interstate that just so happens to be somewhat lower-volume than Allston-west, teardown is a debate...while not all that active today...that we can very plausibly see heating up over the next 20 years. And possibly cresting enough to put this one on the board as a fast project starts. The fact that you can chuck in some beneficial Back Bay flood fortifications in the same fairly inexpensive package will be a nifty assist.

----------------

Not to thread-derail too much from the present-day subject with this, but ^this^ is exactly why what you do after Charles is built is completely, totally, absolutely de-coupled from going to Charles. Those trade-in terms of engagement about bringing the Kenmore project into existence have to happen first in due time. It's not possible to simply mission-creep the Charles extension into a Phase II bootstrap, just as doing this build can't really have jack to do with anyone's desire to consolidate downtown stations because accessibility-under-load requirements will dictate whether "Master Stations" conceptually have any more reality than a dream.

Red-Blue fully provisions for going anywhere once you reach Charles MGH, so the important work gets done right here for anyone who wants to take the rest to the "Crazy/Reasonable Transit Pitches" threads. And that is also why the Bowdoin curve speed restriction looms large, and the Bowdoin curve dimensional restriction. If we're prepping to go truly anywhere outbound of Charles at the 100-year-level, we better truly be giving Blue the capacity throughput to make good on it. That curve straightening really isn't optional.
 

Arlington

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From FMCB meeting:
  • Consultant has been engaged to identify a preferred alternative for design, construction staging.
  • Goal is to have an RFP ready for environmental permitting in Fall 2020.
Set up as though they're building this. Aiello mentioned MGH is delighted about this and wants to make sure their construction is coordinated. No mention of headhouses. Need to mention headhouses.
I am quoting this from upthread. It is entering a stage of design indicative of a will to build.
 

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