Green Line Extension to Medford & Union Sq

Union square station
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i was a real little kid when it was happening, so my perspective was surely not 100% accurate, but i feel like the three-station extention of the red line in the early/mid '80s -- davis, porter, alewife -- went way faster than this green line thing and those stations are actual, bigass stations and serious projects. what is so complicated about making some outdoor platforms and laying track alongside already-existing track in a space that already exists for the new line?
 
i was a real little kid when it was happening, so my perspective was surely not 100% accurate, but i feel like the three-station extention of the red line in the early/mid '80s -- davis, porter, alewife -- went way faster than this green line thing and those stations are actual, bigass stations and serious projects. what is so complicated about making some outdoor platforms and laying track alongside already-existing track in a space that already exists for the new line?

It can be interpreted from the Wikipedia article that construction of the Red Line extension was approx. January 1981 to March 1985.


Groundbreaking for GLX was June 2018. It will (theoretically) be fully operational in December 2021. So a bit over 4 years for RLX vs. 3.5 years for GLX.
 
i was a real little kid when it was happening, so my perspective was surely not 100% accurate, but i feel like the three-station extention of the red line in the early/mid '80s -- davis, porter, alewife -- went way faster than this green line thing and those stations are actual, bigass stations and serious projects. what is so complicated about making some outdoor platforms and laying track alongside already-existing track in a space that already exists for the new line?

The difference between building something brand-new (RL tunnel) versus relocating (a [commuter] rail line) and then building a new line next to it.

EDIT: Basically, building two new lines versus just one.
 
The difference between building something brand-new (RL tunnel) versus relocating (a [commuter] rail line) and then building a new line next to it.

EDIT: Basically, building two new lines versus just one.
Yea, this.
I didn't quite realize the extent of the work needed for the GLX till I saw it being done.
Basically building a new stretch of commuter rail and a new stretch of T rail the length of one of the most densely populated cities in America all while keeping car, bus and train traffic moving and letting residents get some sort of sleep at night. Rebuilding bridges, drainage, building new cuts and widening stretches. The size of the stations seems to be a tiny part of what this job involves.
Don't get me wrong, it's been a huge upheaval to Somerville but I'm definitely not sitting here thinking they are dragging their heals on this project.
 
i guess that all makes sense. i also don't feel like they're dragging their heels -- it just doesn't make intuitive sense to me that three BIG (particularly porter and alewife, both of which are absolute monsters) stations and all the new track takes ony half a year longer (assuming GLX is, indeed, done in 4 years. fun fact: it won't be) than building outdoor platforms and moving a commuter rail track while also laying the new one (as ra84970 put it "building two lines versus just one"). eh, whatever.
 
The other piece to consider when comparing today's GLX to the RLX of yesteryear -- GLX was stuck in planning limbo (or maybe planning hell) for decades, but a Red Line extension beyond Harvard had been thrown around for at least 35 years before it was built. Of course, those same plans for extension-past-Harvard also called for even more ambitious extensions-past-Lechmere, so...
 
The other piece to consider when comparing today's GLX to the RLX of yesteryear -- GLX was stuck in planning limbo (or maybe planning hell) for decades, but a Red Line extension beyond Harvard had been thrown around for at least 35 years before it was built. Of course, those same plans for extension-past-Harvard also called for even more ambitious extensions-past-Lechmere, so...

While that's true, however complicated in the execution, extending light rail along the side of a commuter rail line and deep bore-tunneling a metro line out of Harvard Square are not in the same universe of ambition. I don't think we have a similarly audacious concept in the pipeline today.
 
While that's true, however complicated in the execution, extending light rail along the side of a commuter rail line and deep bore-tunneling a metro line out of Harvard Square are not in the same universe of ambition. I don't think we have a similarly audacious concept in the pipeline today.

True! If we're comparing past projects, better analogs would be:
  • Haymarket North Extension
  • Braintree Extension
  • Orange Line - Southwest Corridor
Interestingly, I think if GLX opens in a year, then all of the above projects would have taken longer than GLX from groundbreaking to completion. I could be wrong, though.

It seems to me that once we got past all of the preliminary issues, construction has moved along at a reasonable pace.
 
True! If we're comparing past projects, better analogs would be:
  • Haymarket North Extension
  • Braintree Extension
  • Orange Line - Southwest Corridor
Interestingly, I think if GLX opens in a year, then all of the above projects would have taken longer than GLX from groundbreaking to completion. I could be wrong, though.

It seems to me that once we got past all of the preliminary issues, construction has moved along at a reasonable pace.

Agreed and to be honest I'm surprised somewhat that there wasn't something hidden under the surface that kaboshed the budget on this project. I know it's mostly previously built upon right of way but still like no plumes of oil soaked dirt or surprise half-mile long stone walls hidden by the embankments
 
For more clarification on the timeline: Northwest Extension construction took a full seven years.

Heavy construction on the Northwest Extension began in late 1978/early 1979; Harvard/Brattle opened in March 1979 as a bus transfer point as the Harvard busway closed. The old Harvard station closed in January 1981, replaced with Harvard/Holyoke, as construction had progressed to the point where the old station needed to be demolished. Only the Church Street entrance to the new Harvard station opened in September 1983, though tracks were operational to the Davis crossover by that time. Davis and Porter opened in 1984, and Alewife and the main Harvard headhouse/lobby in March 1985. Harvard busway reopened in September 1985, and the Alewife crossovers weren't in full service until that December.
 
True! If we're comparing past projects, better analogs would be:
  • Haymarket North Extension
  • Braintree Extension
  • Orange Line - Southwest Corridor
Interestingly, I think if GLX opens in a year, then all of the above projects would have taken longer than GLX from groundbreaking to completion. I could be wrong, though.

It seems to me that once we got past all of the preliminary issues, construction has moved along at a reasonable pace.

Haymarket-North the closest, because Reading Line commuter service and B&M freight service was retained alongside throughout. NETransit's MBTA service histories compendium notes no long-term suspensions of service during that build, so it probably was done around weekend bustitutions much like GLX/Lowell. Including the replacement of the former Mystic River drawbridge with the current 4-track fixed bridge, wholesale bridge replacements @ Malden Center, and relocation of the Mystic Jct. split with a (then considerably longer and more customer-active) Medford Branch to the roof of the new Wellington Tunnel pour. Given the large-scale structures that had to be accommodated with minimal disruption, that's the one that fits most closely. Oak Grove trailed the rest of the extension's opening by 2 years, but was substantially under-construction simultaneous with the rest of the project.


The SW Corridor involved an 8-year shutdown to completely knock down the old elevated NEC embankment and create the new cut...no finessing, all brute-force. Providence/Stoughton, Franklin, and Amtrak all relocated to a freshly upgraded Fairmount Line for the duration, while Needham service was suspended for the entirety. The Orange Line South Cove tunnel connection was waiting as a completed shell for 12 years prior to groundbreaking, only needing final outfitting. It was an enormous undertaking to sink the ROW, but given that most of the affected abutting properties were already acquired by MassDOT for the canceled I-95 extension and this was the cancelled highway's replacement project, they were pretty much able to make as loud a mess as they wanted cleanrooming it all. So very much a different animal in terms of accommodation. Except at cross streets accommodation was pretty much nonexistent.

Red Line South Shore extension was done in multiple chunks:
  1. Columbia Jct. to Quincy Ctr. yard. ROW purchased from NYNH&H July 1965, constructed 1966-71, opened 9/1/71. End of track was Granite St. south of QC (underneath present-day Stop & Shop HQ's air rights garage). Included new Neponset River Bridge and demolition of old RR drawbridge that burned down in 1966.
  2. Cabot Yard. Land purchased from Penn Central 12/1969, constructed 1972-74, RL lead tracks from Columbia opened June 1974; bus garage opened Dec. 1974.
  3. Braintree was deadlocked by disputes over station sitings (North Braintree + South Braintree vs. Quincy Adams + South Braintree) and had to be bid out for complete re-study in 1969 to break the deadlock. Planning malingered into the late-70's, and most construction ended up taking place simultaneous with the Alewife extension, 1976-80. Braintree opened 3/22/1980, QA was slated to open simultaneous but had numerous construction issues and slipped to 9/10/1983 opening.
  4. JFK was an Ashmont-only station until the Braintree platform opened in 1988 after a year's worth of construction.
No commuter rail traffic whatsoever, 1958-1997. Penn Central had abandoned Dover St. Yard by the time it was purchased by the state for Cabot Yard. There was no thru freight traffic Boston-Braintee after 1966 because of the burned drawbridge. Local freights ran a couple days a week from Southie to Boston Globe, the ex- Freeport St. spur that underpassed the Ashmont Branch by Savin Hill in the now-capped tunnel, and Milton Lower Mills via the Mattapan Branch (on the rail-trailed segment + a single RR track that ran alongside the High Speed Line to Central Ave.). 1 or 2 itty-bitty zit customers still existed in Quincy at time of construction (as far as North Quincy and the burnt drawbridge) but were gone by end-70's. For the Quincy Ctr.-Braintree '80 extension Braintree Yard (then as now source of daily dropoffs from Fore River Transportation off the Greenbush Line and pickups via Attleboro-Middleboro-Braintree on then-Conrail/now-CSX) was undisturbed, and multiple day-per-week service to the West Quincy Industrial Track (out-of-service since 2002) which used to have several customers and stretch within eyesight of I-93N @ the Furnace Brook Pkwy. exit. The RL-over-RR overpass and associated inclines would've been constructed here around the West Quincy jobs, which weren't frequent enough to be disrupted. So between the extreme scarcity of adjacent RR traffic to plan around and the out-of-sequence chunking of the build, not a lot of accommodation required. There was undoubtedly more street grid disruption in Quincy Ctr. during the main thrust of the '66-71 build down in the trench, but that was the only place on the whole corridor it would've been halfway-acute levels of disruption at any given time.
 
True! If we're comparing past projects, better analogs would be:
  • Haymarket North Extension
  • Braintree Extension
  • Orange Line - Southwest Corridor
Interestingly, I think if GLX opens in a year, then all of the above projects would have taken longer than GLX from groundbreaking to completion. I could be wrong, though.

It seems to me that once we got past all of the preliminary issues, construction has moved along at a reasonable pace.

I think a modern equivalent to Red-to-Alewife would be something like Blue-to-Kenmore. Extension from an urban terminus that makes no sense, some cut and cover combined with some deeper, more complicated tunneling. If, you know, anyone in MA government was actually talking about it. It's hard enough to get them to address the comparatively much easier RBX and Blue-to-Lynn.
 
  • Still on schedule for 12/2021 completion of the whole project.
  • Still planning to open stations in phases to help with training operators, etc. Almost assured but not required that Union and Lechmere be the first stations to go live some time in mid-2021. Not committed to a specific date.
How long do y'all think it'll be before the T starts rolling out new Green Line / system maps including GLX? It can't be long, right? Or is this going to be a "sticker update" situation for the coming future?
 
How long do y'all think it'll be before the T starts rolling out new Green Line / system maps including GLX? It can't be long, right? Or is this going to be a "sticker update" situation for the coming future?

'Stencil' update. They can chop off all the Arborway stops still showing all over on signage and re-glue them attached to Lechmere instead.
 
Does the way the glx tracks straighten out for the platforms at union sq affect the possible future extension? If the extension ever comes will they be able to add the extension right off the end of the tracks, or will they need to rip up the station and round off the tracks to match the commuter line curve? Its hard to tell in the pictures.

Heres a post showing what Im talking about:
 
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I'm ignorant on the subject, as I wasn't really paying attention to this when they were in the planning, but why did they decide to construct the Union Square branch with this? GLX-Porter makes sense, and I understand all the reasons one would want Green to Porter and beyond, but at completion of this GLX, it seems the catchment area for the two branches will strongly overlap. Those directly in Union Square benefit a great deal, but how, on a cash-strapped project, did they justify adding this single-stop branch on?
 
Those directly in Union Square benefit a great deal
Answered your own question right there!

Less cynically, I'm guessing the city of Somerville did a great deal of lobbying to make it happen. My understanding is they've been pushing hard to redevelop Union Square to increase their commercial office space, and without a visible transit link it'd be a much harder sell.
 
USq station structure is perfectly set up to extend to Porter--but the Prospect St viaduct and (long existing) power substation were not (and were never going to be, no matter what)

So at the USq station they built 100% of what was consistent with going farther, did no demolition, and added as little as possible that might need demolition later

In fact they VEd/deleted the station's tie in directly to The Prospect Viaduct (deleting 2 elevators and an escalator was an easy savings because it might have needed demolition when it comes time to redo Prospect)

And to go outward on the outbound side they'll first have to spend the big bucks and redo Prospect and the electric Substation.
 
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