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Old 05-17-2019, 03:30 PM   #2981
HenryAlan
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Re: Green Line Extension to Medford & Union Sq

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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Old 05-17-2019, 04:22 PM   #2982
sm89
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Re: Green Line Extension to Medford & Union Sq

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Originally Posted by Rover View Post
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.
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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Old 05-17-2019, 05:33 PM   #2983
HelloBostonHi
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Re: Green Line Extension to Medford & Union Sq

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Originally Posted by HenryAlan View Post
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.
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
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Old 05-17-2019, 05:35 PM   #2984
HelloBostonHi
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Re: Green Line Extension to Medford & Union Sq

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Originally Posted by sm89 View Post
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.
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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Old 05-17-2019, 06:02 PM   #2985
sm89
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Re: Green Line Extension to Medford & Union Sq

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Originally Posted by HelloBostonHi View Post
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...
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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Old 05-17-2019, 07:14 PM   #2986
F-Line to Dudley
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Re: Green Line Extension to Medford & Union Sq

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Originally Posted by HenryAlan View Post
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.
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.
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Old 05-17-2019, 08:18 PM   #2987
Arlington
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Re: Green Line Extension to Medford & Union Sq

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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Old 05-17-2019, 10:20 PM   #2988
F-Line to Dudley
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Re: Green Line Extension to Medford & Union Sq

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Originally Posted by Arlington View Post
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
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.
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Old 05-19-2019, 11:34 AM   #2989
ceo
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Re: Green Line Extension to Medford & Union Sq

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Originally Posted by F-Line to Dudley View Post
The 9's will also be able to trainline with the Type 10's.
I hadn't heard that. What's the point?
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Old 05-19-2019, 01:50 PM   #2990
F-Line to Dudley
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Re: Green Line Extension to Medford & Union Sq

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Originally Posted by ceo View Post
I hadn't heard that. What's the point?
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.
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Old 05-20-2019, 02:02 PM   #2991
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Re: Green Line Extension to Medford & Union Sq

Quote:
Originally Posted by sm89 View Post
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.
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.
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Old 05-20-2019, 08:09 PM   #2992
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Re: Green Line Extension to Medford & Union Sq

Site prep.









North of Zinc



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Old 05-20-2019, 08:29 PM   #2993
Arlington
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Re: Green Line Extension to Medford & Union Sq

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.
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Old Yesterday, 02:39 PM   #2994
Tallguy
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Re: Green Line Extension to Medford & Union Sq

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.
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