Green Line Extension to Medford & Union Sq

FitchburgLine

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Almost- the branch to the right will go nowhere for now. It’s pointed towards the yard, but the current designs connect the yard tracks to the Medford branch via a fly under.
 

sneijder

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Is there any shared infrastructure that can be installed when the GLX wire is strung up over the tracks? I know that Fitchburg/Lowell aren't priorities for early electrification under RER/RUR and voltage is different from the 25k AC standard for EMU's...but can the four sets of wires at least share a frame & poles to save some equipment down the road?
 

Arlington

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Is there any shared infrastructure that can be installed when the GLX wire is strung up over the tracks?
Good question.

We are getting a lot of other things (bridges, sound walls, drainage) rebuilt as "4 track" infrastructure for the next 50 ~ 100 years, but I don't think there was an opportunity missed in not building bigger (4 track) catenary systems.

They are so different (GLX = 600V DC, RUR = 25,000V 60Hz AC), that I suspect the greater economies of scale are found by each system buying its own equipment at scale.
 
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Arlington

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At College Avenue, They have started laying the ties for the new position of the commuter rail.

EDIT: Pictures here:
on the MBTA Green Line Extension Facebook site
Including this one showing (from left to right) the sound walls under construction, the new ties being laid for the CR shift, and the foundation walls of Tufts' new building:
GLXatCollAve.jpg
 
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Arlington

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The Nov. 5th Update was posted on the GLX site. It has some interesting stuff:
1) The Washington St Bridge closure has been re-timed. The underpass will stay closed this winter, but in exchange work on it will finish c. April 2020 -- 5 months earlier than originally planned.
2) Lots of station "100% design" details are now available such as the counts of benches and extent of platform sheltering
3) Lots of construction photos with explanations of what you're seeing.
 

jass

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The Nov. 5th Update was posted on the GLX site. It has some interesting stuff:
1) The Washington St Bridge closure has been re-timed. The underpass will stay closed this winter, but in exchange work on it will finish c. April 2020 -- 5 months earlier than originally planned.
2) Lots of station "100% design" details are now available such as the counts of benches and extent of platform sheltering
3) Lots of construction photos with explanations of what you're seeing.
Is it just me or are the slides really blurry?

For Union square, having one egress point be emergency only is a huge offense to those living on the other side.
 

Arlington

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Is it just me or are the slides really blurry?
The station design images are certainly too small.
For Union square, having one egress point be emergency only is a huge offense to those living on the other side.
I think the station entrances suck generally, usually involving a long perpendicular walk away from the street you entered from, and somehow never reaching out on the "both sides" or "both ends"
 

F-Line to Dudley

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Good question.

We are getting a lot of other things (bridges, sound walls, drainage) rebuilt as "4 track" infrastructure for the next 50 ~ 100 years, but I don't think there was an opportunity missed in not building bigger (4 track) catenary systems.

They are so different (GLX = 600V DC, RUR = 25,000V 60Hz AC), that I suspect the greater economies of scale are found by each system buying its own equipment at scale.
Eh. You could install poles on the center-divider fence between the CR and GL sides of the ROW capable of hoisting catenary bracket arms over each side...but that's reaaaaalllly splitting hairs as the unit cost difference in the parts ordered is probably not more than a few hundred bucks at most. The NH Main is a protected Plate F (17 ft. tall) freight route end-to-end from Concord, NH to the Cobble Hill/ex- Yard 10 turnout. Per the terms of the B&M line sales that allowed the T to cannibalize the Fitchburg Cutoff for the Red Line Alewife extension, the high-and-wide clearance route into town was required to flip from the Fitchburg Line (where it then used the Cutoff to avoid a bunch of low bridges Mass Ave.-east) over to the Lowell Line and be given special protected status in perpetuity. The state then re-cleared the whole line during a 1979 bridge raising + trackbed undercutting project to fulfill its end of the bargain. A 25 kV line over a Plate F car requires 19.5 ft. of total clearance (i.e. whatever the car's vertical envelope is +2.5 ft. of electrical arc safety clearance), so they're going to have a lot of work to do in the Somerville trench doing another round of trackbed undercuts before they're able to string up the commuter rail wire. Won't require any touches to the finished GLX side, but lineside structures will definitely be shifting around in places as they hack their way around the big squeezes underneath bridges. Without any prelim engineering whatsoever as to a northside 25 kV power distro system, there's virtually nothing the GLX team can do to anticipate even the *incidental* places where their electric hardware will be installed in close proximity to the future CR electrification. And since that incidental hardware envelope overlap isn't a cost-bloater to begin with...Keep It Simple Stupid.
 

ulrichomega

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Is it just me or are the slides really blurry?

For Union square, having one egress point be emergency only is a huge offense to those living on the other side.
It looks like they're trying to minimize pedestrian track-crossings? Seems absurd because they've already got another at East Somerville, but I'm sure there's a legal/logistics/operations reason why they're restricting people from crossing tracks.

Looking at it more, though, the East Somerville station seems to have just horrible connectivity to the surrounding neighborhood. Why didn't they flip the station to the other side of Washington and use the additional height to not need a pedestrian track crossing? It seems like a perfect location to simply have a staircase coming up from Washington Street directly into the station. It also puts the station closer to everything that isn't just industrial buildings. Or, the very very least, just swap which entrance is the emergency exit?

EDIT: Looking at things a bit more, it does appear as though there's too much of a grade to have a station north of Washington St. I still think the entrance/exit should be swapped though.

It's great to see future platform extensions already planned for, though.
 

whighlander

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Anyone see the American Experience program "The Race Underground" about the building of the original subway in Boston?

If you get a chance it’s worth the 1 hr time commitment

There are some issues with the material and presentation -- for example there is no mention made of Thomson & Houston Company of Boston / Lynn [a founding part of GE] who actually installed the working electrification of the West End Street Railway. In the program a great deal is made of the Sprague Company which did a preliminary installation [more of a proof of concept than anything] but ultimately did not participate in the operational installation. *1

However despite those a couple of other minor issues about who owned -- what there were some important points including:

  1. Boston in 1880 was the densest city in the US
  2. When Mr. Whitney was done consolidating the various horsecar lines into the West End Street Railway -- WESR was the largest Transit System in the WORLD with over 200 miles of lines [initially horse drawn cars] with 2131 cars hauled by 8,000 horses [soon to be replaced by motors]*2
  3. The shear speed at which the project progressed [both the original electrification of the WESR and the later building of the tunnel] -- this speed was despite complicating issues such as: a gas line leak and explosion, and accidentally un-burying some souls down by Boylston T Station
  4. The 250,000 people who used the Subway on its first day of operation and some 50 Million people who used it in its first year of operation --those are significant numbers even by today's standards


*1
From the IEEE Milestone on the Electrification of the Boston Streetcar System
  • 27 June 1889: Thomson-Houston is awarded their first large electric contract: furnish between 240 to 600 streetcar motors, provide maintenance services, and install overhead lines. The contract for generators and switchboards came a few months later
  • July 1889 Contracts to erect the temporary power house are awarded
  • Aug 1889 Start excavation and site work for the permanent Central Power Station
  • Oct 1889 EP Allis, manufacturer of steam engines from Milwaukee, is awarded the contract for six triple expansion Corliss Reynolds steam engines. The largest ever made.
  • Oct 1889 Temporary power station is complete;100 cars are in service.
  • Nov 23 1889 Boston Globe announces that company conductors will begin training
  • Dec 1889 Company shops are very busy building and testing cars
  • Dec 12 1890 Newspaper announces that lightning rods and copper grounding downcomers were installed on top of CPS's chimney
  • Dec 24 1891 The first two steam engines with countershafts and generators are inaugurated
  • Construction continued at a steady pace until the entire network was electric.

*2
from History of the West End Street Railway
 

vanshnookenraggen

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Does anyone know if there is a budget breakdown for the cost of this project? I did some Google searches but I didn't find anything specific.
 

FitchburgLine

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Does anyone know if there is a budget breakdown for the cost of this project? I did some Google searches but I didn't find anything specific.
954m base, <100m options. Not sure of internal breakdowns in the current contract, and since money is fungible any such data wouldn't mean much
 

vanshnookenraggen

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954m base, <100m options. Not sure of internal breakdowns in the current contract, and since money is fungible any such data wouldn't mean much
I'm looking for at least an estimate of the parts broken down. There must have been one as part of the EIS.
 

FitchburgLine

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I'm looking for at least an estimate of the parts broken down. There must have been one as part of the EIS.
The EIS, which came out 1 decade before the current round of bids, is highly unlikely to have relevant cost breakdowns. The bid documents do not have a cost breakdown in the (public) technical specifications, but maybe the price scoring is FOIA-able
 

Arlington

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