Green Line Extension to Medford & Union Sq

Rover said:
Great, then cancel the whole bike path thing and stick with the primary focus of the project, the Green Line extension. Works for me.

FK4 has a fair point about lets see the final cost estimate. I was using figures someone else had posted for the 500M, but really even if its half that I can't see justifying that much money to give bikers the ability to ride like lunatics down the path. Call it a pedestrian walkway then and ban bikes as long as its not adding to the total cost. This project has already had enough overruns.
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People on bikes need to get to the station too. It's like saying ban buses from dropping people off at the station because they'll cause traffic on nearby streets. Let's also remember that the project came in so insanely under budget that they were able to add all the options and still be below the MBTA's Engineer's Estimate.
 
HenryAlan said:
No, the Type 9s will mix in with everything else. The extension creates the requirement for additional cars, which will happen to be Type 9, but dispatch will continue to function across all branches and those cars will see service all over the place.
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Although I will say that so far I've exclusively seen them in revenue service on the D branch so there is something to be said there. I'm sure/hoping it will balance as more roll out. But beyond testing on other lines, D is the only revenue service I've seen. And still only on weekday off-peak mid afternoon hours. newtrains.today
 
sm89 said:
People on bikes need to get to the station too. It's like saying ban buses from dropping people off at the station because they'll cause traffic on nearby streets. Let's also remember that the project came in so insanely under budget that they were able to add all the options and still be below the MBTA's Engineer's Estimate.
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Hate to be that person but the MBTA engineer estimates are usually inflated 20% or so because bids coming in under budget sounds so much better than coming in over budget. Management looks badly on projects where bids come in over estimate and complain but never do the same for underestimates...
 
HelloBostonHi said:
Hate to be that person but the MBTA engineer estimates are usually inflated 20% or so because bids coming in under budget sounds so much better than coming in over budget. Management looks badly on projects where bids come in over estimate and complain but never do the same for underestimates...
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I've done a few Engineer's Estimates over the years, not always for MBTA projects, but there have been a couple that I helped with. You use the standard bid items and the MassDOT averages for a lot of it, but you are right that there is a contingency built in, mostly because transit work doesn't have many comps in this region. There ends up being a lot of lump sum items in the contract. If you look at the awarded projects on the MBTA's website, some are over, some are under, but I didn't see a trend that would make me think that there is a strategy to overestimate.
 
HenryAlan said:
No, the Type 9s will mix in with everything else. The extension creates the requirement for additional cars, which will happen to be Type 9, but dispatch will continue to function across all branches and those cars will see service all over the place.
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The 9's will also be able to trainline with the Type 10's. They broke backwards compatibility on trainlining with the 7's & 8's to make sure they were at a technological baseline that could be forward-compatible instead. Even though the make/model of the next fleet is not yet known, the software mods required to make them talk to the CAF's shouldn't be a big deal.

It's all code tweaks nowadays, whereas the work required to make the 7's and 8's behave in a lash-up was more akin to electro-mechanical voodoo.
 
So the 9s will:
Probably be clustered on 1 line / yard / shop (?)
mix in traffic with 7/8s
Trainline only with other 9s and future 10s

And so 9s will not be trainlined with 7/8
 
Arlington said:
So the 9s will:
Probably be clustered on 1 line / yard / shop (?)
mix in traffic with 7/8s
Trainline only with other 9s and future 10s

And so 9s will not be trainlined with 7/8
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Stuff gets mixed around the system enough during the service day that they'll make appearances on all lines. Right now they're only on the D because non-accepted cars live at Riverside and one of the revenue cars needs to get borrowed to do testing. But that's exactly how it went with the Type 8's when they were first being delivered.

Per the GLT study, the D and E are the two lines nearest-ready to have 2-car "stretched" trains of Type 10's...with the B and C still having too many short platforms to renovate. 5+ years from now you'll probably see the 9's skewed more heavily to BC and Cleveland Circle where 10-9 consists are better able to fit than 10-10's.
 
ceo said:
I hadn't heard that. What's the point?
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Universal compatibility. All vehicles on the roster will be able to trainline with all other vehicles. Isolated fleets suck for ops cohesiveness, so this is important even when the CAF's are a minority fleet.

Also, see last post. The Type 10's, because they're much longer, won't be able to platform a two-car train at many surface stops on the B and C until the stop renovation backlog is tamed. Which isn't anticipated until after 2030 because of the number of stops that need to be modded. Only the D and E will be ready to take paired cars at the start. While the individual stretched cars do have enough interior capacity that Type 10 singlets can approximate the seating capacity of today's two-car 7-8 consists, the B's overcrowding makes the inability to run two-car trains there a problem for however many years it'll take to get the last stops (some contingent on Comm Ave. Phase III reconstruction) compliant.

Running 10-9 consists, however, can buy time for the platform work by adding extra capacity sooner as some of the platforms that need to be modded for 10-10's can take a 10-9 as-is, while it's a much shorter list of station mods skewed to the particularly short platforms required to bring 10-9's online. Meaning, instead of waiting past 2030 to get a two-car supertrain they can front-load some platforms sooner to enable 10-9 mixes and be under less financial pressure for the final finish-up of the station program.
 
sm89 said:
I've done a few Engineer's Estimates over the years, not always for MBTA projects, but there have been a couple that I helped with. You use the standard bid items and the MassDOT averages for a lot of it, but you are right that there is a contingency built in, mostly because transit work doesn't have many comps in this region. There ends up being a lot of lump sum items in the contract. If you look at the awarded projects on the MBTA's website, some are over, some are under, but I didn't see a trend that would make me think that there is a strategy to overestimate.
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I do these all the time. I start with the MassDOT Weighted Bid Averages and make adjustments based on economy of scale or vice-versa and add in contingency factors. The aim is to have an estimate that is around the average, as you never want to have something that represents the low bid. But you don't inflate the numbers without sound justification in doing so.
 
Have they said for how long Lechmere will be bustituted?

If they have secured the right to build New Lechmere and most of its new viaduct, then the closure could be limited to just the time it takes to replace the viaduct on the two blocks of common alignment that both old and new will use.

If the deal still is that they can't take possession of the new stations parcel until they've given the current site to Delaware North then it will be a long closure.
 
Has anyone seen any maps, renderings or videos of what EXACTLY is being built at the junction of Union and Medford lines? I have seen some preliminary stuff, but who knows now.
Van, have you updated your map yet?

Also, can anyone ID sources of GLX cost at a more granular level ie individual stations, tracklaying, viaduct, maintenance yards etc.
 
Looking north from Lowell St- some type of work protection being set up:


North from Cedar St- retaining wall piling work, plus Broadway excavation in the background.


South from School St- Homan's building demolition and staging for drainage.



East from McGrath- supporting column construction for the Union Sq branch.



Behind Cambridge Antique Market- grading and staging of columns.


East from Water St- rebar cages and prep for Lechemere Station
 
Honestly, I still can't believe this is happening.

Great photos, FitchburgLine, thanks for sharing!
 
I've been wondering what they're doing between Cedar and Lowell Streets. They've filled and graded the GLX ROW almost up to street level, is that just for equipment access from behind the DPW garage?
 
Downburst said:
Honestly, I still can't believe this is happening.

Great photos, FitchburgLine, thanks for sharing!
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I want to say this because a while back, back during we were in limbo, I once got into an argument where I got hammered down that we haven't got into the "real" construction yet. I got pounded so hard when I made that comment (not here, different website). Yes, I'm sure the project before the stoppage wasn't doing absolutely nothing. I mean there was some visible work and I wasn't going out of the way to look.

But right now, what we are experiencing with all the closures, crews, overnight work, cranes into the sky - yes, this what I meant by "real" construction.
 
ceo said:
I've been wondering what they're doing between Cedar and Lowell Streets. They've filled and graded the GLX ROW almost up to street level, is that just for equipment access from behind the DPW garage?
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I was also wondering about that- it seems like the RoW is too narrow without that space, so likely it's a temporary ramp.
 
Tallguy said:
Van, have you updated your map yet?
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I need to check what I've added. The problem is I don't have exact locations for switches and I'm not 100% on what they are doing with the new yard. If anyone can get me that info I'll add it to the map.
 
They are building up a temporary stabilized earth berm to support the drilling rig installing the noise wall foundations.
 
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