Green Line Reconfiguration

[F-Line to Dudley]

I think I prefer the deadend at Harvard Sq, and to spend any additional budget for more GL UR at Longwood.

Longwood can be accommodated by boosting D frequencies...easiest means for that running supplemental E's diverted to Brookline Village on E-to-D surface connecting trackage, then sending them inbound to Kenmore Loop. The Ring, being a radial, never promised--even in its wildest MOAR TUNNEL south-half acid dreams--a one-seat ride from Logan to Southie the back way. The ridership overchurns often...and the quadrants are useful metric of chunking the service because you can specific-target some of the overlaps (such as Sullivan-Kendall-Harvard being a high-demand one-seat for North Shore commuters but not so much for anybody coming anywhere south who's going to make their Red vs. Orange transfers earlier).

So in this case you aren't hell-or-high-water trying to replace the 66 with a one-seat. The 66 itself will never go away; it just gets relieved of a lot of scheudle-killing overcrowding by turning into "the Harvard-Allston local that then becomes the cross-Brookline local that then becomes the cross-JP local" with way fewer end-to-enders needing to sweat out the clock. The convenience is enabled by simply being able to hop one platform at Kenmore between an incoming Harvard Branch train and anything D. If the loopage-from-E supplement is there the D's Longwood Station would get twice the service while the E's LMA stop would get the wrap-around option, and the micro-targeted doubling of transfer headways at peak (which won't hurt traffic because Kenmore Loop only intermixes with C/D platform berths and the D is far under-capacity) shortens the wait on the platform hop.


Where you can see this eventually going is upping the ante on E enhancements. First the relocation off Copley Jct. and reattachment to Boylston/South End + Back Bay Station. And eventually lighting a fire under extending the Huntington Tunnel to Brookline Village for a full alt-spining of the Central Subway. Because then you'd have bi-directional junctions for service multi-routings at:

• Brickbottom: junction of Central Subway (all thru + Brattle Loop), Urban Ring NW-or-Union Branch, Urban Ring NE, Medford Branch
• BU Bridge: junction of Central Subway (inbound + Park/GC Loop), Urban Ring NW-or-Harvard Branch, B Line
• Brookline Village(-ish): junction of Central Subway (inbound + Kenmore Loop), E/Huntington, D Line, South Huntington streetcar
• South End: junction of Central Subway (northbound, Park/GC Loop, all Brickbottom routings), E/Huntington (incl. all Brookline Vill. routings), Transitway, Washington St. streetcar

...and the exponential service increases and routing variety that ensues.

We have one major unbreached conundrum with all these neato UR NW+NE renders: what about the south half Ring? We know that cannot be practically built with grade separation, because we'll all be dead eons before there's enough money and cooperation to MOAR TUNNEL all that. And the capacity constraints of on-street BRT or LRT are way more restrictive than the north half. Kenmore-Dudley and Dudley-Seaport are still very good projects even if they have to be BRT on some mixture of reservation bus lanes and striped/mixed bus lanes...but how do we give them an assist on the load-bearing capacity of the Ring? Well, look ^above^ at the exponential linkage being encouraged on the Green Line. That Kenmore Loop bend-back alt flavor of E that's goosing the cross-platform transfers for the diverted 66 riders? Well...if you put some urgency behind the giddayup of that Huntington installment plan the South End junction that eventually takes up the E has multi-direction routing from the E to Dudley OR Seaport. And that Huntington tunnel buildout to BV eventually pipes the capacity. So those Kenmore Loop trains that started out once upon a time as just grab-n'-go spot augmentation are now a major trunk 'circuit' in their own right supporting numerous routing flavors.

So maybe instead of envisioning the south-half BRT Ring SW & SE quadrants being load-bearing like the grade-separated north half, those Kenmore Loop runs turn permanent and scoot Kenmore-Dudley + Kenmore-Seaport as an augmented load-bearing pipe and the BRT-on-striped-lanes crosstown route traces the more faithful 2D arc between Kenmore, Longwood, JP/Roxbury, and Dudley on the surface. And they mutually complement by the alt-spined LRT being able to pipe the crowding at greater frequencies, while the BRT faithfully traces the 'tweener spots in arc corridor and adheres to better schedules from far less overloading. And by working them both in tandem they cumulatively achieve all of the goals that the MOAR TUNNEL killshot would have...except in installments we can actually string together in 25 years of self-pacing instead of likely never being able to build at all.


That's where I think the Urban Ring starts resembling this thread's namesake: "Green Line Reconfiguration". It's the first planks in totally remaking what purpose the Green Line serves. It's not a drop-in replacement for a bunch of one-seat routes taffy-stretched beyond their usefulness. Instead it totally remakes the idea of what a linked trip in Boston is and how convenient it should be by remaking the GL as not a trunk-with-spokes (...or even trunk-with-spokes that we're going to do this 'one' neat radial trick with), but rather a whole dynamic web. We haven't seen anything like that on the service side since maybe the very earliest BERy terminal days...and never ever before scaled to this kind of capacity.

Personally, I think popping our cherry on just the ONE first dip at converting the Grand Junction to NW Ring (+ West starter stub) is enough to ram this point home that it ends up filling the project pipe for another 30 years of constant-churn augmentation to build out the rest of the system. Attractively, none of the individual cogs are in-and-of-themselves all that expensive. Green-Transitway as replacement for Silver Line Phase III is probably the only one complicated enough and monolithic enough to be a $B's megaproject, and that has to be done for a wide-ranging many other reasons than just radial coattails. The other legs discussed have very reasonable costs and are well-insulated from each other for pacing oneself on the installments...and are ripe for micro-targeting and shape-shifting the service plans to fit demand curves that'll be very different on Opening Day vs. 20th Service Anniversary. The momentum gained by starting the first build is enough to carry the momentum forward for the second, the third, and so on.

 

[Highwayguy]

There may be a good reason for the GL tracks to be North of the CR tracks on the Union branch, but l cant help but think this is a prime example of T short sightedness. This alignment necessitates a crazy (and tight) flying junction under the McGrath to tie into the GJ, instead of a mundane flat junction if the GL was on the other side of the tracks. I’m not convinced that the GJ to Union branch underpass is even feasible because of the proximity of the Union branch viaduct. The incline starts just about at the foot of the McGrath overpass. Even if it is it will probably be another Boylston curve situation because of the tight coners on nasty grades, but without the proximity of a station to minimize loss time. And yes im aware of the need in the meantime to maintain N/S equipment moves; the row is plenty wide enough to support a single track lead to the engine terminal on the south side of the Green line until the flyover.

 

[ceo]

NOTES: GLX project does not have up-to-date schematics of the Brickbottom flyovers and carhouse track configuration...only online docs are ooooollllld.

These are from 2019 and match the as-built as I've observed it so far:
Union Square branch plan(25M PDF)
McGrath-area plan (50M PDF)

Unfortunately these diagrams don't give any information about how how the ramps and flyovers are configured, so it's hard to tell exactly where a UR line will fit.

 

[ceo]

There may be a good reason for the GL tracks to be North of the CR tracks on the Union branch, but l cant help but think this is a prime example of T short sightedness.

So the Grand Junction can connect to the Fitchburg Line, of course.

 

[F-Line to Dudley]

View attachment 5126
There may be a good reason for the GL tracks to be North of the CR tracks on the Union branch, but l cant help but think this is a prime example of T short sightedness. This alignment necessitates a crazy (and tight) flying junction under the McGrath to tie into the GJ, instead of a mundane flat junction if the GL was on the other side of the tracks. I’m not convinced that the GJ to Union branch underpass is even feasible because of the proximity of the Union branch viaduct. The incline starts just about at the foot of the McGrath overpass. Even if it is it will probably be another Boylston curve situation because of the tight coners on nasty grades, but without the proximity of a station to minimize loss time. And yes im aware of the need in the meantime to maintain N/S equipment moves; the row is plenty wide enough to support a single track lead to the engine terminal on the south side of the Green line until the flyover.

Incorrect. The ROW is not "plenty wide" enough, because all current RR traffic from the Grand Junction always goes straight to the north flank of BET crossing 3-5 tracks in the process...never continuing south-flank along the Fitchburg Main. Prior to GLX construction there wasn't even a switch to the Fitchburg Main...literally just a bunch of switchless track diamonds cutting straight over to the north. This is because all equipment swaps enter/exit from the north; Downeaster layover permanently lives there so that's where the Amtrak portion of the N-S lash-ups go, and majority of the time swaps are heading straight to/from the wye to change locomotives and cab cars to the service-facing direction of where they're going. CSX freights ran until July 2019 exclusively passing through the back to get on the Eastern Route to Everett, and CSX still today retains the rights there because the customers Pan Am is handling via the new haulage agreement are still CSX signees. If they are at all dissatisfied with Pan Am's performance on the haulage agreement they can terminate at-will and resume job B721 out of Framingham exactly like before. When it's Urban Ring time the T will square loss of the GJ by giving them overhead trackage rights on the inner Fitchburg Line from Ayer (CSX already has Worcester-Ayer rights) so they can keep retaining those Everett customers or opt at any time to serve Everett again (because if the Terminal expands they may have lucrative-enough new biz to chase)...and then it's just state wrapping a candy-coated freight grant at them to get their wink-wink approval for the federal Surface Transportation Board filing that landbanks the GJ off the FRA network.

There is not enough room to squeeze hard by the ex- Red Bridge cut for a south-flanking RR track that has GLX tracks in the middle...then get GLX out of there...then clear the Fitchburg cut in time to kamikaze-cross before the north-flank BET tracks are pulling off. It only works for the West-North Station dinky...not the equipment swaps (esp. the Amtrak stuff) and not for the still-extant freight rights. To create any more bandwidth, you'd first be doing additional property-takings of the businesses on O'Brien at the Twin City light, beginning with the storage warehouse. Land-takings like that aren't reasonably justifiable when there's nothing forcing them on the table except own-personal design fussiness. Therefore, they made absolutely the correct decision siting the GLX tracks on the north side. LRT can incline at >4% grades making a 12 ft. rise or drop quick, and meaning that most of this duck-under can be an inexpensive open-daylight cut with the Fitchburg tracks passing overhead on bridges...more alike where the Red Line and Old Colony main trade places south of Quincy Adams than the Wellington tunnel. You'll be making that jump-under with strobed sunlight coming into the trolley windows virtually the whole way...not in tunnel darkness.

As for the Union Junction...re-read the paragraph immediately above that picture grab. Some months ago we had a back-and-forth kvetching erupt about exactly the spacing concerns you bring up. We broke out the calculators, poured through the documents, spatially analyzed the various Street View panoramas giving 360 view of the underside of McGrath. Conclusion was the margins had enough give in them to do it comfortably...comfortably against all remaining uncertainty remaining from the amateur aB tape-measuring job. Board-search for that tiresome exchange from several months ago if that's keeping one up at night...I really don't feel like bandwidth-wasting a rehash of it right now. It's hairs-splitting, not viability-threatening. You aren't zooming off the Brickbottom flyovers at 50 MPH to begin with; the whole area is a slow meander, and is why Lechmere-Union on a stopwatch isn't :50 faster than the official docs say it is. It's still a non-concern in the big picture.

 

[F-Line to Dudley]

These are from 2019 and match the as-built as I've observed it so far:
Union Square branch plan(25M PDF)
McGrath-area plan (50M PDF)

Unfortunately these diagrams don't give any information about how how the ramps and flyovers are configured, so it's hard to tell exactly where a UR line will fit.

Not "fit"..."is located". "Fit" entails some uncertainty that the movements can be done. We absolutely 100.00% know the movements can be done, because GLX couldn't operate without those movements being 100.00% possible. The only thing we don't know for sure is where the actual steel/concrete is being actively erected, because there's an annoying little documentation gap on the final-final carhouse schematic coming after they kissed and made up with the Innerbelt NIMBY's and inked the Memorandum of Understanding.

Non-revenue service passage Lechmere<==>carhouse and Union Branch<==>carhouse is fluidly baked into the junction's design. Because Union Sq. Station has no tail tracks of it's own it's ironclad required that it be able to slip deadheads to/from the carhouse inside the margins of a 6-min. headway. During the service day you'll see many trains on either side of the island go out of service and pull straight out "No Passengers" rather than do a full layover for reversing direction...same as how a random-odds Alewife turn may opt to pull into the yard rather than immediately reopen doors. All mundane forms of turnover like operator shift changes will get staged with 'tweener scoots from the Union platform to the carhouse, as well as contingencies like delay recovery from gapping/bunching downtown where they've got to dump a bunching glut of incoming trains while resetting the departing headways. When this staging is in effect you may see a paused "No Passengers" train staged and waiting stopped just behind the carhouse-side switches on the flyovers as your train is passing by...waiting for the green light on next open mid-headway scoot slot. The distance to Union platform is short enough that this is completely adequate practice until you extend the line to Porter, in which case you'll need the usual 1-2 trainsets of slack storage on the tail tracks.

Movements across the junction are 100.00% guaranteed, and we know the carhouse parcel abuts the wrap-around tracks on the whole slab of land up to the 3rd Ave. driveway grade crossing for BET (it's cut off in your third link as the shaded parcel at the top. So full scope of work at enabling full-on revenue moves out of these 100.00% allowable non-revenue movements is how you go about switch-separating 2 mainline tracks from yard limits without too-badly pinching the remaining storage. There's umpteen ways that's feasible so there's no fatal blockers...but which of the umpteen feasible ways balances the needs and spits out the resulting track schematic that gets spliced in place of that "SCENE MISSING" placeholder in Part 0 of that post. That I don't know...because my 1-of-umpteeen guess probably isn't going to have lifelike accuracy to how the T chooses to do it.

But in no way does it mean there's a "fit = feasibility" issue here, nor should anyone worry about that. The Union Branch as slated to open in a couple of years would not be cleanly operable if the grunt work on the flyovers wasn't done beforehand...because those non-revenue carhouse scoots are the real-deal ops prereq for the branch that's under active construction.

 

[Highwayguy]

Incorrect. The ROW is not "plenty wide" enough, because all current RR traffic from the Grand Junction always goes straight to the north flank of BET crossing 3-5 tracks in the process...never continuing south-flank along the Fitchburg Main. Prior to GLX construction there wasn't even a switch to the Fitchburg Main...literally just a bunch of switchless track diamonds cutting straight over to the north. This is because all equipment swaps enter/exit from the north; Downeaster layover permanently lives there so that's where the Amtrak portion of the N-S lash-ups go, and majority of the time swaps are heading straight to/from the wye to change locomotives and cab cars to the service-facing direction of where they're going. CSX freights ran until July 2019 exclusively passing through the back to get on the Eastern Route to Everett, and CSX still today retains the rights there because the customers Pan Am is handling via the new haulage agreement are still CSX signees. If they are at all dissatisfied with Pan Am's performance on the haulage agreement they can terminate at-will and resume job B721 out of Framingham exactly like before. When it's Urban Ring time the T will square loss of the GJ by giving them overhead trackage rights on the inner Fitchburg Line from Ayer (CSX already has Worcester-Ayer rights) so they can keep retaining those Everett customers or opt at any time to serve Everett again (because if the Terminal expands they may have lucrative-enough new biz to chase)...and then it's just state wrapping a candy-coated freight grant at them to get their wink-wink approval for the federal Surface Transportation Board filing that landbanks the GJ off the FRA network.

There is not enough room to squeeze hard by the ex- Red Bridge cut for a south-flanking RR track that has GLX tracks in the middle...then get GLX out of there...then clear the Fitchburg cut in time to kamikaze-cross before the north-flank BET tracks are pulling off. It only works for the West-North Station dinky...not the equipment swaps (esp. the Amtrak stuff) and not for the still-extant freight rights. To create any more bandwidth, you'd first be doing additional property-takings of the businesses on O'Brien at the Twin City light, beginning with the storage warehouse. Land-takings like that aren't reasonably justifiable when there's nothing forcing them on the table except own-personal design fussiness. Therefore, they made absolutely the correct decision siting the GLX tracks on the north side. LRT can incline at >4% grades making a 12 ft. rise or drop quick, and meaning that most of this duck-under can be an inexpensive open-daylight cut with the Fitchburg tracks passing overhead on bridges...more alike where the Red Line and Old Colony main trade places south of Quincy Adams than the Wellington tunnel. You'll be making that jump-under with strobed sunlight coming into the trolley windows virtually the whole way...not in tunnel darkness.

As for the Union Junction...re-read the paragraph immediately above that picture grab. Some months ago we had a back-and-forth kvetching erupt about exactly the spacing concerns you bring up. We broke out the calculators, poured through the documents, spatially analyzed the various Street View panoramas giving 360 view of the underside of McGrath. Conclusion was the margins had enough give in them to do it comfortably...comfortably against all remaining uncertainty remaining from the amateur aB tape-measuring job. Board-search for that tiresome exchange from several months ago if that's keeping one up at night...I really don't feel like bandwidth-wasting a rehash of it right now. It's hairs-splitting, not viability-threatening. You aren't zooming off the Brickbottom flyovers at 50 MPH to begin with; the whole area is a slow meander, and is why Lechmere-Union on a stopwatch isn't :50 faster than the official docs say it is. It's still a non-concern in the big picture.

Well theres my good reason.

 

[ceo]

Oh, getting from the Union Square branch to the carhouse isn't the issue I'm concerned about. I'm wondering how to bring the line from the Grand Junction ROW in. The Union Square Branch southbound track ramps up to join the Medford Branch immediately after crossing under McGrath, so there's nowhere near enough distance for the Grand Junction southbound track to ramp up to meet it after crossing under the Fitchburg Line. And as it ramps up, it has to take up a track width, so you end up with 6 tracks going under the bridge. Because of where the piers are located (they're marked on the diagram I linked), there is space for only 4.

About the only way I see to do it is to demo 61 Medford St (side note: I worked in that building right after college, when it was a Lotus fulfillment center) and the Prime Storage building, and cut straight across their footprint so you can locate the track junctions completely clear of the bridge. The southbound GJ track would have to split off to the right of the Union Square track, ramp down in the Russell parking lot, and then cross under all four tracks. But I'm still not convinced there's enough space for the northbound track to come up and join the Union Square branch before the bridge.

 

[F-Line to Dudley]

Oh, getting from the Union Square branch to the carhouse isn't the issue I'm concerned about. I'm wondering how to bring the line from the Grand Junction ROW in. The Union Square Branch southbound track ramps up to join the Medford Branch immediately after crossing under McGrath, so there's nowhere near enough distance for the Grand Junction southbound track to ramp up to meet it after crossing under the Fitchburg Line. And as it ramps up, it has to take up a track width, so you end up with 6 tracks going under the bridge. Because of where the piers are located (they're marked on the diagram I linked), there is space for only 4.

About the only way I see to do it is to demo 61 Medford St (side note: I worked in that building right after college, when it was a Lotus fulfillment center) and the Prime Storage building, and cut straight across their footprint so you can locate the track junctions completely clear of the bridge. The southbound GJ track would have to split off to the right of the Union Square track, ramp down in the Russell parking lot, and then cross under all four tracks. But I'm still not convinced there's enough space for the northbound track to come up and join the Union Square branch before the bridge.

GLX design standards, in the official GLX design guide on the T website, allow for 4% sustained grades and 6% allowable grades within an individual 2500 ft. running section bookended by level ground. On the duck-under you'd be able to go to a 12 ft. minimum vertical underclearance from the GLX Union and Fitchburg tracks above. So at 4% grades you can get down from ground level to maximum depth in 300 ft., and at 6% get down there in an envelope-pushing 200 ft. The McGrath overpass spans 200 ft. over the tracks, and the Grand Junction property line meets the Fitchburg property line 75 ft. west of McGrath (with the current RR track hugging the extreme-south property fence). West of the overpass there is more room to play with if the rear parking rump of 1 Beyond on Medford St. is taken, which would expand the GJ property line to 175 ft. behind the bridge without knocking any buildings down. Now, the approach from the GJ to the Fitchburg Line has already inclined down to maximum depth before it approaches, so any parking lot easements from 1 Beyond are mainly for squaring the most of the curvature on-alignment to Union inbound before ever engaging the first set of McGrath overpass pilings. Assuming the underside of McGrath itself is 200 linear ft. and there may be a little more curvature left to square around the first set of pegs, you can still make 80% or more of the incline to track level before seeing daylight on the east side of McGrath.


Any and all remaining area of uncertainty between what you know you can accomplish on incline-up before the flyovers come into play comes down to about a 40 ft. stretch east of the bridge. And no, we do not have enough information right now today on 5/10/2020 from the available schematics to rule out possibility of a conflict within those 40 feet because we don't know if the base of the flyover is 10 ft., 25 ft., 50 feet from the 2D east limits of the bridge from these schematics. If anyone wants to lose sleep over that or keep hammering away at it every time this comes up...you will get no further clarity here. But the fact of the matter is that if 40 feet is your only mathematical uncertainty in the whole world on whether that junction is buildable...you do have at-cost mitigation options somewhere to smooth it over. Most likely taking place clear on the east side of the bridge with a mod of the last few feet of flyover where a faster-inclining set of UR tracks hits the switch at a flattening-out Union a few feet before it hits ground level. Which would require maybe 5 feet's worth of track-shifting of the Fitchburg side east of the bridge...but wrappable before it makes a close pass to Life Storage and thus requiring no land-taking.

That or probably a dozen other strategies that are similarly unsatisfying means of calming down anyone who's really going to stress out to the last hundredths of a percentage point on feasibility for lack of official documentation. I do not think ^^that game of inches^^ is going to upend the entirety of the Urban Ring and salt the earth clear from BU to Sullivan. It's inconceivable that even if it does come down to that game of inches that there isn't enough difference to be made up west and east of the bridge that feasibility will be imperiled. But if you want that perfection now...today...send a FOIA request to the state. Because neither your own eyes nor asking someone on the Internet to show all the math is going to keep the last hundredths of a percent variance from boring a hole in one's head. Nobody who isn't a staffed GLX project engineer has access to the full/final measurements.


I think, however, that an ascertained 99._% feasibility is quite above threshold for advancing this to revised DEIR and picking up the Alternatives Evaluation from the MIS that hasn't been touched in any way/shape/form in over 12 years. aB's Green Line Reconfig thread isn't going to build the fucking thing itself, after all...so if there's an advocacy point behind this whole nutsy-boltsy discussion it's that it's PAST TIME for this thing to go back to study front-burner. Especially when that hot mess of faltering urban vision @ West is begging a lot of existential questions in real-time about exactly what mobility should look like on this corridor.

 

[ceo]

I'm clearly missing something here. 200 feet from the west side of the McGrath overpass on the second-from-northernmost track location already puts you past the end of 61 Medford St. (Remember that the entire business has to be west of the bridge, because there are 4 track slots under it and they are all taken.) And the GLX design criteria manual specifies 14'7" as the absolute minimum vertical clearance, plus you need a few feet for the overpass itself, so realistically you're looking at more like 18 feet. Even at 6%, that's 300 feet right there, and then there's the turnout which is at least another 50 (it can probably be partially under the bridge).

Unless the Union Square branch mainline itself ramps down under the bridge, and there's a flat junction at the bottom. That would work, though the flat junction would be kind of a pain.

 

[F-Line to Dudley]

I'm clearly missing something here. 200 feet from the west side of the McGrath overpass on the second-from-northernmost track location already puts you past the end of 61 Medford St. (Remember that the entire business has to be west of the bridge, because there are 4 track slots under it and they are all taken.) And the GLX design criteria manual specifies 14'7" as the absolute minimum vertical clearance, plus you need a few feet for the overpass itself, so realistically you're looking at more like 18 feet. Even at 6%, that's 300 feet right there, and then there's the turnout which is at least another 50 (it can probably be partially under the bridge).

Unless the Union Square branch mainline itself ramps down under the bridge, and there's a flat junction at the bottom. That would work, though the flat junction would be kind of a pain.

Incorrect. 240 ft. is the measurement from west end of bridge to corner of 61 Medford building. Which is why I stated an upper-bound 175 ft. for taking the rear parking corner for curve allowances down at the bottom of the trench prior to the first McGrath pilings, and not a tally greater than that.

14'7"is the minimum physical clearance without written waiver:

2. Deviation from clearances described in the CRDSM and in this criteria require prior written approval by the MBTA.

With written approval from the MBTA it can go down to the Central Subway ruling height limit.


Again...we can split these hairs for 18 more pages of this exchange if it's so keeping you up at night. You will not get 100.00% certainty from a messageboard debate. FOIA the GLX project team if it's so extremely important to nail down 40 ft. of fudge factor that cannot be checked-off squeaky clean by any third-party means. I have zero intention of doing on-demand math homework over last 0.01% uncertainties, because that information isn't available to me either without an FOIA and that was pre-acknowledged up-front. And I have zero intention of encouraging this thread to get dragged down that wormhole on implicit 'onus' to bat away any/all of those 0.01% feasibility questions when Post #1 of these renders to today has made it abundantly clear that I can't credibly do that without access to the information. We...are...not...going...there.

My point is exactly the same as it was in the last post: if you have ascertained >99% build feasibility amid a hot ongoing discourse about the burning need for a substantial corridor transit plan linking West, BU, and Kendall...we are way past the threshold for picking up the 12-years-stale DEIR and finishing the LRT vs. BRT project scoping into a FEIR. It is extremely, extremely unlikely that such official analysis is going to find blockers in such extremely narrowly constrained areas of uncertainty...but hundredths-of-percent variances are a fact of life. You finish the scoping to settle those details; no project passes "Go" without that step. If you want to spend outsized attention catastrophizing about 0.01%'s when we still aren't funding an FEIR...knock yourself out. Others can equally feel free to use ascertained 99%+ feasibility as an advocacy pivot for finishing the next logical steps. Eye of the beholder: use it to enable the discourse or use it inhibit.

 

[Deetroyt]

F-Line, what do you see as the rolling out order of your described projects? Obviously UR NW quadrant as you've described would be a first step before getting thru Chelsea or over to Harvard, but what about the south half? Do you envision that coming after the NW and NE quadrants are done via LRT? I ask because if the southern half of the ring is going to be BRT, it seems like that would be relatively easy to implement sooner by creating some bus only lanes.

Admittedly i haven't studied any of the state's UR docs so this is purely me looking at googlemaps, and drawing (and apologies if this should be moved to the UR thread), but it seems by taking some parking and doing light digging you could have dedicated bus lanes from Kenmore most of the way. Start west on Beacon to reach Lansdowne, turning south on Park (not sure if a Fenway stop makes sense since you can hit the line at Kenmore?), and then using Fenway. Not sure what the ideal integration with Longwood is, Brookline Ave could support bus lanes but the trouble is Longwood Ave. Maybe just dropping off at Avenue Louis Pasteur, or actually putting bus lanes down Avenue Louis Pasteur, having it loop at Longwood Ave and come back down ALP, since that drops off at the heart of Longwood neighborhood and ALP could support bus only lanes by taking parking or by widening. The stretch of Louis Prang from Huntington to Evans Way will not support bus lanes, though it is a short stretch. Once across Huntington (obviously including a stop at Museum of Fine Arts) Ruggles St. could be widened to add bus lanes in each direction, since I believe this was planned to be highway and ripping out the trees in front of West Village would be easy. Stop at Ruggles station then continue in dedicated lanes down Melnea Cass, spurring south to stop at Dudley. Bus lanes on Melnea to the Mass Ave. intersection, then Southampton to Andrew station, though you're missing Newmarket so I'm not sure if preference would be to find a way down Mass Ave. and Columbia Rd. since JFK/Umass has Old Colony riders that may prefer one transfer to Longwood?

Anyways my point wasn't to say this makes the most sense from ridership-needs perspective - the official studies presumably have that info and this plan should be adjusted to fit - just that implementation of something like this seems pretty easy as it doesn't require tunnels or much heavy construction and still radially connects the main passenger destinations along the route (Kenmore, Lansdown, Longwood, Ruggles, Dudley, Andrew) and could be built for relatively cheap $$.

 

[ceo]

Incorrect. 240 ft. is the measurement from west end of bridge to corner of 61 Medford building. Which is why I stated an upper-bound 175 ft. for taking the rear parking corner for curve allowances down at the bottom of the trench prior to the first McGrath pilings, and not a tally greater than that.

You're still missing my fundamental point: the ramp-down CANNOT be under the bridge, because the piers are in the way. Or are you assuming all along that reconstructing the bridge would be part of this? That's actually not that disruptive; there's plenty of room between the abutments for all 6 tracks (though we might have to decide we don't need Somerville Ave. Extension anymore), and there are 2 separate spans so you can replace one of them at a time without closing the entire bridge.

 

[F-Line to Dudley]

Well...the original goal was that the CTx system of Crosstown buses was to be fleshed out with many more routes such that the core arc segments of the UR first got established as on-street buses. This was what Phase I of the MIS specced for Crosstown routes:

• CT1 - Central Square (Cambridge) to Andrew Station via Massachusetts Avenue
• CT2 - Sullivan Square to Ruggles via Union Square (Somerville), Kendall Square and Boston University Bridge
• CT3 - Longwood Medical Area to Airport Station and terminals via Ruggles, Boston Medical Center, and Ted Williams Tunnel
• CT4 - Ruggles Station to UMass Boston Campus via Dudley Square and Uphams Corner
• CT5 - Logan Airport to Sullivan Square via Downtown Chelsea, Wellington, and Assembly Square
• CT6 - Downtown Chelsea to Kendall/MIT via Community College and Lechmere
• CT7 - Kendall/MIT to Franklin Park via Mass Ave Bridge, Kenmore, Longwood Medical Area, Ruggles, Dudley, and Grove Hall
• CT8 - Sullivan Square to Longwood Medical Area via Union Square Somerville, Central Square Cambridge, Cambridgeport, Boston University Bridge, and Fenway Station
• CT9 - Kenmore to Harvard Square via Commonwealth Ave and Allston
• CT10 - Kenmore to JFK/UMass via Longwood Medical Area, Ruggles, and Boston Medical Center
• CT11 - Longwood Medical Area to Fields Corner via Ruggles, Boston Medical Center, and Uphams Corner
• EC1 - Anderson Regional Transportation Center to MIT at Mass Ave via Sullivan Square, Lechmere, and Kendall
• EC2 - Riverside to Lechmere via Mass Pike, Central Square, and Kendall
• EC3 - Natick to Copley Square via Mass Pike

With an assumption of the bus lane and signal priority features that have subsequently been fleshed out in the Key Bus Route and Better Bus plans, that gives you some idea of how these would have worked in mixed traffic. Some of these routes you can clearly see trace high-demand turnover points on the grade-separated Ring, and would have been pulled into the dedicated ROW upon Phase II. CT2, CT5, CT6, and CT9 the spot-on matches...while CT7, CT8, CT10 and others are partial matches. The system would've evolved via absorption of the on-street CTx's onto the dedicated ROW's, with some CT's (like CT1 most obviously) remaining independent and spurring other radial expansion of the Crosstown system. The fact that none of this was followed through upon, and the Crosstown system stagnated right then and there, is one of the biggest failures of the original MIS. It was supposed to spur on a lot of constantly-churning multimodal work apart from the scoping decisions on dedicated ROW's and running BRT vs. LRT on them. Instead the whole thing was written off as a monolith and thrown in a cabinet. That's tragic. Nothing should've stopped the CTx's from being their own everlasting breakout initiative with yearly-installment enhancements, but that's exactly what the cro-magnons in charge of the T at the time ran screaming from.

So basically you'd start there cranking up the Better Bus features. Especially with GLX bringing about a great reboot of the Somerville local routes you'll have an opportunity to shape-shift things around in the Kendall-Lechmere-Sullivan area to glom new patterns to areas of future-leaning demand. That's definitely a supporting effort, and any pickup of the studies needs to include thorough treatment of the surrounding Yellow Line ecosystem to look for synergies. So the "project" as it were is not a track-laying monolith. It can definitely start with some long overdue things like tossing the 66 a life raft in the form of something leveraging West Station akin to the CT9 from the above list here, and also fighting the good fight on congestion around the poorly-striped BU Bridge rotary in Cambridge + traffic-taming the Carlton/Mountfort clusterfuck on the BU side with a compacted single-signal intersection so Kenmore can take more schedule-reliable buses than today. All of that is mutually-serving to the end goal of carving out the dedicated ROW on the corridor. All multimodal efforts should be part-and-parcel pulling the same direction.

The funnest (I guess for this thread's purpose) part is that you can have a bonanza crayon-redrawing bus routes...both the ones that route-prime arcs of the corridor ahead of shovels-in-ground work, the ones that seed the south half with a spider's web that can be load-bearing despite the absence of dedicated ROW's, and the complementary routes that hit the major transfer points. UR planning...both the design work on the dedicated ROW portions and the service-side augments elsewhere, is a sort of Pied Piper for Better Bus seeding around the CBD. So whether the actual Ring quadrants fly the Green or Silver flag...it's as much a Yellow project on the follow-thru as anything else because matching up high-frequency to high-frequency transfers is the name of the game.

 

[F-Line to Dudley]

You're still missing my fundamental point: the ramp-down CANNOT be under the bridge, because the piers are in the way. Or are you assuming all along that reconstructing the bridge would be part of this? That's actually not that disruptive; there's plenty of room between the abutments for all 6 tracks (though we might have to decide we don't need Somerville Ave. Extension anymore), and there are 2 separate spans so you can replace one of them at a time without closing the entire bridge.

I have no idea what your point is, because each successive reply is micro-splitting more hairs. We've isolated the fudge factor on either side of the bridge, and the underside of the bridge apart from the piers is physically wider than the tracks it's carrying. Meaning if you get the curving in the pit over with before engaging any of the pilings there is lateral room to split and incline...one track between Union inound and the nearest Fitchburg track, one track flanking the outside of the bridge footprint. How much room, to the inch, do you have??? I don't fucking know; I would have to FOIA to find out, and I'm not going to. You've still maneuvered feasibility well past the threshold of functional doubt where the experts can pick up the unfinished DEIR and put some engineering exactitude to it in an FEIR.

THAT's the point of this exercise: to prove it can be advanced to FEIR. I can't square those last remainders, and if you keep hammering-hammering-hammering with more nitpicks the answer is never going to be any different. There will always be decimal-point remainders that the general public cannot verify. But there's your roadmap to how we find it out from the experts. We can either work with that to get the project advanced to formal study, or waste bandwidth laser-splitting ever smaller hairs and dragging the thread into nihilistic wormholes instead of expanding this discussion to other interesting areas (like Deetroyt's last post on breakout bus coattails). I have no intention of encouraging more of this.

 

[ulrichomega]

...if you keep hammering-hammering-hammering with more nitpicks the answer is never going to be any different. There will always be decimal-point remainders that the general public cannot verify. But there's your roadmap to how we find it out from the experts. We can either work with that to get the project advanced to formal study, or waste bandwidth laser-splitting ever smaller hairs and dragging the thread into nihilistic wormholes instead of expanding this discussion to other interesting areas (like Deetroyt's last post on breakout bus coattails). I have no intention of encouraging more of this.

ceo just seems to be trying to understand the limitations of the currently-under-construction infrastructure and what work it would take to patch in an UR connection. Unless your posts here constitute the FEIR justification itself what's the point in shutting them down every time they try to ask a question?

RE: Their actual question: I agree that the under-bridge space looks tight for six track-widths worth of junction and running track. F-Line, are you proposing putting the outbound+westbound UR tracks to the north of the northern pier, gobbling up that part of Somerville Ave? The span where Fitchburg goes through now is about forty feet across, so I'd be nervous about banking on four track-widths through there without some pier work. Which would be fine, it's just a matter of curiosity about if that would be required or not.

 

[F-Line to Dudley]

ceo just seems to be trying to understand the limitations of the currently-under-construction infrastructure and what work it would take to patch in an UR connection. Unless your posts here constitute the FEIR justification itself what's the point in shutting them down every time they try to ask a question?

Perhaps stating it ^exactly such^--"What's the lay of the land in areas X, Y, Z?" would be better than asking one discrete question...getting the best-available answer to that one question...then pivoting immediately to someplace different "...but you didn't say anything about here". What is this...a moving-target game of gotcha?

Somebody politely asked for a re-posting of the old V1 of the Ring renders that the photo host ate because this was topical discussion. That's what it was posted for. If this is being perceived at any level as some silly game somebody has to 'win', then I'm sorry for them for misinterpreting a simple MS Paint photo request as a fucking manifesto forced upon the board. If that's where this is going, then consider myself duly chastened for ever making the effort in the first place.

 

[ceo]

I have no idea what your point is, because each successive reply is micro-splitting more hairs. We've isolated the fudge factor on either side of the bridge, and the underside of the bridge apart from the piers is physically wider than the tracks it's carrying.

You know, it would be kind of nice if you actually read my posts. I have been saying the same thing all along: a) the existing bridge pier configuration provides slots for four tracks, not six, and b) there is nowhere near enough distance for the turnouts and ramps to be located entirely west of the bridge.

Now, I might be wrong about a). Looking at this diagram again, it looks like there might be room to squeeze 6 tracks around the piers. But I have no idea what their foundations look like underground, which is obviously relevant if we're digging trenches right next to them.

But, as I have also been saying, if there really isn't space for 6 tracks, the problem is easily solved by replacing the McGrath Highway bridge superstructure.

 

[F-Line to Dudley]

RE: Their actual question: I agree that the under-bridge space looks tight for six track-widths worth of junction and running track. F-Line, are you proposing putting the outbound+westbound UR tracks to the north of the northern pier, gobbling up that part of Somerville Ave? The span where Fitchburg goes through now is about forty feet across, so I'd be nervous about banking on four track-widths through there without some pier work. Which would be fine, it's just a matter of curiosity about if that would be required or not.

Possibly a flank on Somerville Ave. But also it's currently five tracks--3 Fitchburg, 2 GLX--passing under McGrath and spanning thru to the Medford St. overpass. 3rd Fitchburg track is a re-fashioned remnant of the old "Paint Track" that used to store some work equipment...currently dead-ending at a temporary bumper east of McGrath but with the new Medford St. bridge graded for 5 berths to tie it back into the main more or less where it used to fizz out behind Target (see placement of fence mounts separating GLX from Fitchburg west of Medford St. on Google and you can spot the probable switch point by the west side of Target where the Fitchburg side of the fence starts narrowing back to 2 tracks). "Paint Track" used to be a stub-end, but now with it being a distended full-on tie-in at its western extent it's not likely to be used the same way before as a parking spot for derelict flatcars and other MOW junk. Work equipment shuffled in from Alewife MOW will be taking that new switch tie-in west of Medford St. and riding it to the back of BET. So in the end does it really matter if the switch is east or west of the bridge? Always seemed like a strange retention, especially for forcing Medford St. overpass to be widened by +2 tracks to 5 berths instead of +1 to 4. So while cutting that track is not going to make the BET yardmaster all that happy over the perpetually precarious storage allowances, you could perma-end it with a switch east of the bridge near where the current bumper shows on Google and completely subtract 1 RR track underneath McGrath. Gone.

That immediately buys you all the room in the world to incline-up the northbound/inbound UR track to the northbound/inbound Union track. Keep in mind that 1) all of the inclining-down happens before you turn off the GJ ROW, and 2) the 1 Beyond parking lot easement can widen out the curve further west of the bridge abutments. In that case it's only the UR outbound-to-Union outbound connection that leaves any wiggle room for junctioning uncertainty vs. the bridge abutments. Underside of Somerville Ave. Ext. shows that the first piling on the westerly side is attractively centered (swing Street View around pointing west...then swing it around east to the piling right by the Stop sign, and notice the placement differences on either side). So for that last ~20% of the duck-under's curve you have ample space to complete the turn and be on tangent alignment. The worst-case scenario is that for the outbound side of the flying junction you have to pop up at max 6% grade swinging out over Somerville Ave. Ext. curb if there's no real estate inside the fence for 1 more track. Now there *is* some slack real estate between Union OB and the chain-link fence...we just don't know if it measures out to the last inch fitting inside the fence or overspills the sidewalk. One of those 0.01% uncertainties I simply can't answer. Somerville Ave. Ext. will no longer be required to be any thru street on that wrap-under once McGrath is lane-dieted, because Somerville Ave./Medford St./Poplar St. will have at-grade intersection access when the viaduct is flattened to the same grade as current ground-level 28N at the Poplar traffic island. So it is fully OK if you have to overspill the curb and prohbit motor vehicles under the bridge; there will still be enough space leftover to grade a nice cycle track through there. Best-case...you do fit the rising track inside the fence and don't have to touch the pavement at all.

Remaining uncertainty then becomes the squeeze around that easterly abutment hosting the stop sign...can you squeeze onto the ROW or do you have to swing roadside outside it and nick an inconsequential strip of street corner passing around and then haul ass to meet the start of the flyover incline. Either way you've got fudge factor to solve for the remainder. I can't speculate on the margins, but any which way you're far into the 99th percentile feasibility with what's available and avoid any need to blow up the bridge and re-space the pegs at added expense.

 

[F-Line to Dudley]

You know, it would be kind of nice if you actually read my posts. I have been saying the same thing all along: a) the existing bridge pier configuration provides slots for four tracks, not six, and b) there is nowhere near enough distance for the turnouts and ramps to be located entirely west of the bridge.

Now, I might be wrong about a). Looking at this diagram again, it looks like there might be room to squeeze 6 tracks around the piers. But I have no idea what their foundations look like underground, which is obviously relevant if we're digging trenches right next to them.

But, as I have also been saying, if there really isn't space for 6 tracks, the problem is easily solved by replacing the McGrath Highway bridge superstructure.

It's not four existing tracks...it's five existing tracks. Addressed further in immediate prior post.

That's two of us who aren't reading before replying.