Green Line Extension to Medford & Union Sq

Re: Green Line to Medford to start in 2011

winstonoboogie said:
I believe they are actually tearing down and replacing the elevated structure itself all the way from the Land Blvd/Gilmore Bridge approach intersection to the location of the existing station.
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I'm sure they have a decent story about where the new alignment needs to leave the old (and it is probably longer than any of us are picturing) but still, that's the part that you do last as the final tie in. I agree, if this were a highway, it'd be closed for no more than 3 months.
 
Re: Green Line to Medford to start in 2011

Let's look at the last few times that trains were swapped onto a completely new route:

  • North Station, 2004: Old station closed on June 25, new station opened on June 28.
  • Southwest Corridor, 1987: April 30 - May 4
  • Red Line Northwest Extension, 1983: September 2 - September 6
  • Haymarket North Extension, 1975: April 4 - April 7
  • South Shore Line, 1971: no disruption

So that claim that they need 17 months to make a changeover? I can smell the bullshit a mile away.
 
Re: Green Line to Medford to start in 2011

novitiate said:
I wonder if this has something to do with the deals the MBTA made to get the land for the new station? The new developer would seem to have the most to gain from closing the station at the beginning of reconstruction.
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This is the only reasonable argument that I can come up with. Still, not a good reason to be shutting terminating lechmere service for 17 months. I see no reason why the tie in isn't done towards the end of the Phase 2/2A.

Are there changeovers on the viaduct at all? Could service terminate at Science Park while the changeover is under way? Or is it unwise to have lengthy layovers on the bridge?
 
Re: Green Line to Medford to start in 2011

novitiate said:
I wonder if this has something to do with the deals the MBTA made to get the land for the new station? The new developer would seem to have the most to gain from closing the station at the beginning of reconstruction.
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I bet this is the answer (or close to it)--I think they have to do a parcel swap to "get" the whole new site, meaning they have to surrender the old site.
 
Re: Green Line to Medford to start in 2011

The EGE said:
Let's look at the last few times that trains were swapped onto a completely new route:

  • North Station, 2004: Old station closed on June 25, new station opened on June 28.
  • Southwest Corridor, 1987: April 30 - May 4
  • Red Line Northwest Extension, 1983: September 2 - September 6
  • Haymarket North Extension, 1975: April 4 - April 7
  • South Shore Line, 1971: no disruption

So that claim that they need 17 months to make a changeover? I can smell the bullshit a mile away.
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When the elevated structure at Science Park was cut into the new portal, service was shut down on June 25 2004 and didn't resume operating until November 12, 2005. They had to demolish the old structure west of Science Park station and then build the new ramp occupying the same space.

Based on slide 17 from this presentation
http://greenlineextension.eot.state...tgs/staDesign/Lechmere_Presentation061813.pdf
it looks like a similar situation, as they will have to demolish the existing elevated as far west as Land Blvd and then build the new structure on a slightly different alignment in its place.

That's why it will take 17 months, its not going to be a simple connection between the new station and a new structure with the old, but rather, it will be a new station and a replacement of a significant section of the old elevated with a new structure.
 
Re: Green Line to Medford to start in 2011

One thing that might help is if in addition to the shuttles, the 69, 87,88 and 80 were routed to North Station. And the buses will need a lane on the bridge... will the Longfellow still be closed?
 
Re: Green Line to Medford to start in 2011

Winston: you're correct that they didn't resume Lechmere service for a while. But they did the elevated-to-underground North Station transition over the weekend. MassDOT replaced 14 prefab bridges above 93 in single weekends; now their subsidiary agency is claiming it'll take 17 months to replace a couple hundred feet of viaduct?
 
Re: Green Line to Medford to start in 2011

Great. I'll likely live in Somerville just long enough to get all of the negative construction effects and none of the benefits. 17 months is ridiculous.
 
Re: Green Line to Medford to start in 2011

The EGE said:
Winston: you're correct that they didn't resume Lechmere service for a while. But they did the elevated-to-underground North Station transition over the weekend. MassDOT replaced 14 prefab bridges above 93 in single weekends; now their subsidiary agency is claiming it'll take 17 months to replace a couple hundred feet of viaduct?
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The elevated-to-underground transition at the Science Park end wasn't done over a weekend, it took from June 2004 to November 2005. When service ended in June 2004, they demolished the old structure to the west of Science Park, prepared the site to build the new ramp connection to the new portal, built the ramp connection, and resumed service to Lechmere, 16 months later.
That appears to be the same thing (although without a tunnel portal/ramp) that will be going on here. They will stop service to Lechmere, tear down the elevated structure from the old Lechmere to Land's Blvd (which looks to be about 1000ft), and then build a new elevated structure from Land's Blvd to the new Lechmere.
I suppose they could build a temporary structure over O'Brien Highway from Land's Blvd to old Lechmere, so they could tear down the old structure while maintaining service, but that would be pricey, and the costs for this project are already much higher than anyone would have guessed years ago.
 
Re: Green Line to Medford to start in 2011

If this was a highway project, they would have a temporary viaduct and service would halt for a period of hours in the middle of the night. It's absurd that closure for nearly a year and a half is considered okay.

Couldn't they construct a temporary station in the block bordered by Glassworks Ave, Leighton St, East St and the O'Brien Highway? That way they could demolish the small portion of the viaduct in front of the Archstone building, put in a temporary ramp, have it cross Leighton St at grade, and stay away from construction of the new viaduct. This way service would only have to be interrupted for as long as that one block segment takes to build instead of the whole project, and the current Lechmere site could still be vacated ASAP.

Unlike its predecessors, the MBTA seems to have no knack whatsoever for constructing temporary trackage during construction projects.
 
Re: Green Line to Medford to start in 2011

Where are they going to turn trains to Science Park? They can't turn everything at North Station...
 
Re: Green Line to Medford to start in 2011

Matthew said:
Where are they going to turn trains to Science Park? They can't turn everything at North Station...
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When Lechmere-North Station was closed for Science Park station reconstruction, the C and the E were both terminated at North Station.
 
Re: Green Line to Medford to start in 2011

So that means they won't be able to serve Science Park with green line trains for 17 months either?
 
Re: Green Line to Medford to start in 2011

If the shuttle bus had dedicated lanes, it wouldn't be such a big deal, but of course it won't...
 
Re: Green Line to Medford to start in 2011

Would running the shuttle to Community College or Kendall be better than North Station?

I don't see anywhere to turn a bus around by CC, however.
 
Re: Green Line to Medford to start in 2011

Is that spur off to the right at 0:35 the same track that comes from underneath at 0:51, presumably to the Union branch? I can't help but think how much more tolerable the main trunk of the Green line would be if the C,D, and E branches spurred off similarly (not that I think thats even remotely realistic).
 
Re: Green Line to Medford to start in 2011

DominusNovus said:
Is that spur off to the right at 0:35 the same track that comes from underneath at 0:51, presumably to the Union branch? I can't help but think how much more tolerable the main trunk of the Green line would be if the C,D, and E branches spurred off similarly (not that I think thats even remotely realistic).
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From what I understand the E merge at Copley was supposed to be a flying juntion, but they ran out of money and cheaped out, hence the current bottleneck.

The C/D split is probably due to the constraints of getting under the pike with the existing tunnel. As a branch its not as huge a deal though.
 
Re: Green Line to Medford to start in 2011

Yes, that is the flying junction to the Union Square branch.
 
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