Green Line Extension to Medford & Union Sq

ulrichomega said:
So... it was fine all along and they were just wasting our time?
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It wasn't fine all along - I did speak with someone who would know, and this was a real physical problem that took a few weeks to fix. The contractor built the track at the narrowest edge of spec (by mistake, but approved at the time because it was just barely in spec) and it narrowed further with usage infinitesimally to the point where first a little of it, then a lot of it failed inspection.

There are some new people in charge of line work at the T, and I think hopefully a corner has been turned.

Also...

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I was expecting repairs on the Medford Branch to take deep into November, given only 1 hour or 2 hours overnight to fix it (last train 1:41, first train 4:37. Surprised it took "only" 4 weeks.
 
I’ll be a little bummed when Union reopens and the E branch no longer gets the type 9s. 1) who decided that the 9s would (when the branch is fully open) be D-only and why? 2) why was the type 9 order so small relative to 7 and 8? It’s a drag that the best (by far) GL cars are such rare unicorns.
 
chrisbrat said:
I’ll be a little bummed when Union reopens and the E branch no longer gets the type 9s. 1) who decided that the 9s would (when the branch is fully open) be D-only and why? 2) why was the type 9 order so small relative to 7 and 8? It’s a drag that the best (by far) GL cars are such rare unicorns.
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My understanding is that back in 2012-2014 when they ordered the type 9s that they'd originally considered a much larger order to include replacing a significant portion, if not all, of the type 7s. Ultimately, if I recall correctly, the decision was made to only order enough to sustain the GLX extension, and they basically immediately pivoted to rehabbing the 7s in the interim and planning for the Type 10.
 
chrisbrat said:
I’ll be a little bummed when Union reopens and the E branch no longer gets the type 9s. 1) who decided that the 9s would (when the branch is fully open) be D-only and why? 2) why was the type 9 order so small relative to 7 and 8? It’s a drag that the best (by far) GL cars are such rare unicorns.
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Type 9s are not allowed on the street-running sections of the E branch. IIRC, state laws require light rail vehicles running in mixed traffic to be able to display a STOP sign to alert cars behind them, which the Type 7s and 8 do on their folding doors. Type 9s can't do that as they have swinging doors.
 
I guess they have given up on the bike cage at Gilman. It was supposed to be located near the base of the stairs to Reavis Field.
 
Teban54 said:
Type 9s are not allowed on the street-running sections of the E branch. IIRC, state laws require light rail vehicles running in mixed traffic to be able to display a STOP sign to alert cars behind them, which the Type 7s and 8 do on their folding doors. Type 9s can't do that as they have swinging doors.
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I was watching a Type 9 go by while riding on the path this morning and I noticed that there is a little mirror that extends when the doors open. They've already got a mirror that pops out when the doors open, what is stopping the MBTA from adding a stop sign?
 
Stlin said:
My understanding is that back in 2012-2014 when they ordered the type 9s that they'd originally considered a much larger order to include replacing a significant portion, if not all, of the type 7s. Ultimately, if I recall correctly, the decision was made to only order enough to sustain the GLX extension, and they basically immediately pivoted to rehabbing the 7s in the interim and planning for the Type 10.
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There were contract options with CAF to more than double the number of Type 9's (I think 50 cars was the target) for the introduction of 3-car peak trains nearly everywhere. It wouldn't have replaced the 7's or 8's unless they re-upped for something like 200 more on top of that, so the options in the original contract were strictly a per-train expansionary thing. That obviously fell by the wayside when they moved on to the Type 10's, which would net the seating capacity of Type 7/8/9 triplets with a 2-car 'supertrain'.
 
F-Line to Dudley said:
There were contract options with CAF to more than double the number of Type 9's (I think 50 cars was the target) for the introduction of 3-car peak trains nearly everywhere. It wouldn't have replaced the 7's or 8's unless they re-upped for something like 200 more on top of that, so the options in the original contract were strictly a per-train expansionary thing. That obviously fell by the wayside when they moved on to the Type 10's, which would net the seating capacity of Type 7/8/9 triplets with a 2-car 'supertrain'.
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This is going way off-topic, but are platforms on the entire system long enough for three Type 7-9 cars (and two Type 10 cars)?
 
Teban54 said:
Type 9s are not allowed on the street-running sections of the E branch. IIRC, state laws require light rail vehicles running in mixed traffic to be able to display a STOP sign to alert cars behind them, which the Type 7s and 8 do on their folding doors. Type 9s can't do that as they have swinging doors.
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Thanks! That makes total sense (still a drag that they couldn't have retrofitted the 9s with signage to indicate stops, but oh well).
 
Teban54 said:
This is going way off-topic, but are platforms on the entire system long enough for three Type 7-9 cars (and two Type 10 cars)?
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LRV triplets have run before on the D and B within the last 15 years, and even at Boylston they were able to get all the doors open. Even though some of the platforms (like Boylston) couldn't berth all of the carbody, they were able to berth all of the right-side doors. Though some of the B platforms are maximally snug for that and require *very* precise train stop positioning to get all doors open, which slows ops down and required headways to be lengthened the last time triplets were tried. On the E the main constraint is that only the outer loop at Heath could be used, and on the C Washington Square is definitely much too short so they haven't been featured on the C often or at all in the last 47 years. I'm not sure if any other lesser C stops are too short, but the GLT docs indicate that there's considerable work required on that branch so Washington might not be the only constraint.

The main difference between 7/8/9 triplets and the 'supertrains' is the door configuration. The Type 10's have right-side doors further back of the train than the last set of middle doors on a 7/8/9 consist, so there are platforms which will snugly host a 7/8/9 triplet with some of the rear of the train behind the doors overspilling that definitely won't allow the rear-most doors of a T10 deuce to open. Most of the platform work for the 'supertrains' is going to be on the B and C getting the platforms up-to-spec for comfortable full-speed starts/stops at those train lengths and that particular door config. Because some were so maximally snug to begin with for the door config on existing triplets, there are a lot of stations on those 2 branches that the GLT effort will have to touch to make them compatible with 'supertrain' door layouts. The D will be ready on Day 1, and on the E they really only need to do something about Heath's full 2-track capacity.
 
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Here's the story that also came from Comm. Mag!!!! :)

commonwealthmagazine.org

MBTA says all GLX slow zones are eliminated - CommonWealth Magazine

THE MBTA reported on Wednesday that all of the slow zones on the Green Line extension have been removed – good news that was surprisingly buried in a MassDOT press release about repairs being completed early on the Squires Bridge in Somerville. The T has taken a lot of heat for 3 mile-per-hour...
commonwealthmagazine.org commonwealthmagazine.org
 
So, now that the 3 MPH slow zones have been removed, can we return to the much-earlier discussion about what actually constitutes "line speed" over the Lechmere Viaduct? I can't find the reference right now, but waaaaay upthread I remember reading that the design speed in the GLX documentation was 50 MPH, but more recent discussions have referred to 25 MPH as the speed limit over the viaduct. Is this simply too fine a point to be worth investigating?
 
Steve H said:
So, now that the 3 MPH slow zones have been removed, can we return to the much-earlier discussion about what actually constitutes "line speed" over the Lechmere Viaduct? I can't find the reference right now, but waaaaay upthread I remember reading that the design speed in the GLX documentation was 50 MPH, but more recent discussions have referred to 25 MPH as the speed limit over the viaduct. Is this simply too fine a point to be worth investigating?
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They supposedly fixed that portion of the GLX to supposedly be able to support the much heavier Type 10 super-long trolleys when they go into service after delivery & testing. At least that is what I'm thinking. :)
 
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