Green Line Extension to Medford & Union Sq

devnull said:
I rode across the viaduct in both directions today, and clocked it at ~20-25mph in both directions on my phone's GPS!
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Interesting. The MBTA dashboard still shows a 10 MPH speed restriction southbound.

Although TransitMatters now shows a hudge pudge of a disorganized mess for travel times on the viaduct today.
EDIT: I'm seeing movement, scroll down to the last 2 images. Soundbound is more of a mess than northbound (northbound seems to have cleared)
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I commute over the viaduct daily, and here are my observations from yesterday evening and today:
  • Going northbound (RR eastbound), there’s a posted speed of 20 mph the whole way across the viaduct. I’m not sure why that’s short of the promised 25 mph, but it’s still a massive improvement over 10. The speed limit sign just past the north end of the Science Park platform is much larger than the usual speed limit signs and looks fairly permanent, so I’m not sure what’s going on there.
  • Going southbound (RR westbound), there is still a 10 mph restriction, but it’s been significantly shortened, now starting about 2/3 of the way across. Interestingly, I didn’t see any speed limit signs between the 25 mph sign leaving Lechmere and the new limit of the 10 mph restriction. It seems weird to me that the southbound side is apparently good for 25 but the northbound side is only good for 20.
While there’s still clearly work to be done, this represents a major improvement, especially after several false starts. If there’s more GLX early access work in January to finish addressing the gauge issues, I hope they’re able to make more progress on the viaduct.
 
alewife said:
I commute over the viaduct daily, and here are my observations from yesterday evening and today:
  • Going northbound (RR eastbound), there’s a posted speed of 20 mph the whole way across the viaduct. I’m not sure why that’s short of the promised 25 mph, but it’s still a massive improvement over 10. The speed limit sign just past the north end of the Science Park platform is much larger than the usual speed limit signs and looks fairly permanent, so I’m not sure what’s going on there.
  • Going southbound (RR westbound), there is still a 10 mph restriction, but it’s been significantly shortened, now starting about 2/3 of the way across. Interestingly, I didn’t see any speed limit signs between the 25 mph sign leaving Lechmere and the new limit of the 10 mph restriction. It seems weird to me that the southbound side is apparently good for 25 but the northbound side is only good for 20.
While there’s still clearly work to be done, this represents a major improvement, especially after several false starts. If there’s more GLX early access work in January to finish addressing the gauge issues, I hope they’re able to make more progress on the viaduct.
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Mind also paying some bit of attention to the northbound 5 MPH slowzone between North Station and Science Park?

IIRC the 5 MPH restriction starts towards the end of the last switches and crossovers, and the 600 ft NB slow zone ends at the end of the tunnel.

The MBTA's speed restriction dashboard has shown no progress on this slow zone. This means they cannot bill it as "GLX slow zone free to North Station", as that would be an inaccurate statement to make if this North Station to Science Park slow zone sticks around, and the Lechmere Viaduct is only at 20 MPH average speed and not the promised 25.
 
thepianoperson said:
I don’t think the GLX specs could even apply to the viaduct since the viaduct was a separate project entirely - my guess is that 25mph was always the design speed for the viaduct and the GLX specs were never intended to apply to it even though they imply otherwise.
Speaking of those specs though, it’s interesting to see how they (haven’t) been followed in practice. The end of the viaduct to Lechmere is 25 or 30, I think most of Red bridge is 30 or 35, all switches are 10, and overall line speed seems to be limited to around 40. Does anyone have insight into why this is the case? Is increasing the line speed to 50 ever in the cards? Is the 10 mph over switches rule ever going to be lifted (even if it’s only once they get rid of the Type 8s)? The East Somerville to North Station portion is always disappointingly slow since there’s so many switches in that stretch.
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I found in a Railroad.net forum from 2009 that switch speed limits on the Green Line are indeed due to the Type 8 center section. That's not confirmed information though. The few operator error accidents of the 2000s resulted in the MBTA dropping a lot of speed limits on the Green Line. The Riverside Branch used to be 45-50. Maybe with the successful implementation of the GLTPS they'll be more comfortable raising limits back to design speeds. On the GLX the stop spacing might be a limiting factor because at least in my experience on the line the trains only maintain 40 for a handful of seconds before needing to decelerate.

For maintenance purposes they may keep switch speeds low around yard turnouts and heavy use switches to preserve the frogs longer knowing how cheap the T likes to be historically.
 
I would normally link a news article, but I can't find any. The newest one I can find is WHDH's report that the GLX track work might get extended again. So here's the reddit thread that reports it by connecting 2 and 2 together -
https://www.reddit.com/r/mbta/comments/18o1lhs

If it only extends to January, then it still won't feel too bad once it's over. Like we can look back as a short-term hiccup in summer 2024. But the fact it needed to be extended a 2nd time is starting to broach into fears it's not going be over soon.
 
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Went up to Ball Sq today from Brookline Village to get a feel for how the speeds are doing on the Viaduct and Riverside Branch.

GPS clocked a top speed of 33mph on the Riverside. Not a large sample size because Longwood-Fenway is too short to reach top speed before the switches. North Station NB was indeed speed restriction-free and maybe it was the operator but there wasn't any 5mph zone from North Station to Science Park despite the dashboard saying there is a 0.11 mi one. The lowest the speed dropped was to 10mph past the yard and up the incline. Going NB/WB over the viaduct was very noticeably faster but my dumbass turned off the GPS because I was meeting someone. It felt like it was at least 25mph but felt quicker than the tunnels. SB/EB over the viaduct coming back was different and the 20mph limit was very apparent. Also of note was the operator didn't go beyond 20mph between Gilman and East Somerville SB. May have been at their discretion rather than a legit slow zone.
 
Koopzilla24 said:
Went up to Ball Sq today from Brookline Village to get a feel for how the speeds are doing on the Viaduct and Riverside Branch.

GPS clocked a top speed of 33mph on the Riverside. Not a large sample size because Longwood-Fenway is too short to reach top speed before the switches. North Station NB was indeed speed restriction-free and maybe it was the operator but there wasn't any 5mph zone from North Station to Science Park despite the dashboard saying there is a 0.11 mi one. The lowest the speed dropped was to 10mph past the yard and up the incline. Going NB/WB over the viaduct was very noticeably faster but my dumbass turned off the GPS because I was meeting someone. It felt like it was at least 25mph but felt quicker than the tunnels. SB/EB over the viaduct coming back was different and the 20mph limit was very apparent. Also of note was the operator didn't go beyond 20mph between Gilman and East Somerville SB. May have been at their discretion rather than a legit slow zone.
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To make sure, this is referring the the area towards the end of the switches, and before the end of the tunnel portal right? IIRC the 600 ft NB slow zone ran from near the end of the switches, up to the tunnel portal. (For the North Station -> Science Park slow zone)
 
Delvin4519 said:
To make sure, this is referring the the area towards the end of the switches, and before the end of the tunnel portal right? IIRC the 600 ft NB slow zone ran from near the end of the switches, up to the tunnel portal. (For the North Station -> Science Park slow zone)
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Yes from the end of the switches and following the first curve out of North Station. On the tracks paralleling the yard tracks leading to the portal the train was traveling above the restricted speed.
Operators largely ignore the Warren St>Washington St slow zone on the B since the trains sometimes struggle on that transition to the incline. I wonder if the more senior ones would do the same at the Science Park incline since it’s even steeper. On the other hand there is a signal on the incline and if it’s red they need to stop half on it so…
The Green Line is so especially operator dependent for speed and travel times that the speed restrictions don’t have the most uniform impact.
 
Koopzilla24 said:
Yes from the end of the switches and following the first curve out of North Station. On the tracks paralleling the yard tracks leading to the portal the train was traveling above the restricted speed.
Operators largely ignore the Warren St>Washington St slow zone on the B since the trains sometimes struggle on that transition to the incline. I wonder if the more senior ones would do the same at the Science Park incline since it’s even steeper. On the other hand there is a signal on the incline and if it’s red they need to stop half on it so…
The Green Line is so especially operator dependent for speed and travel times that the speed restrictions don’t have the most uniform impact.
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I’ve noticed in the portal when heading Science Park > North Station there is a stop sign (not signal) that all trains stop at. Is this related to track condition that could ever be resolved, or just to allow operators eyes to adjust to the dark tunnel?
 
Badusername said:
I’ve noticed in the portal when heading Science Park > North Station there is a stop sign (not signal) that all trains stop at. Is this related to track condition that could ever be resolved, or just to allow operators eyes to adjust to the dark tunnel?
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That stop sign is because of the steep grade of the incline. It's both a speed control and brake check. There are multiple of these on the B between Warren St and Sutherland Rd because of the steep hills.
 
Koopzilla24 said:
That stop sign is because of the steep grade of the incline. It's both a speed control and brake check. There are multiple of these on the B between Warren St and Sutherland Rd because of the steep hills.
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I'm not a rail junkie but is this a legal requirement or just the MBTA being overly cautious? There clearly isn't the same standard of safety for personal vehicles..
 
sneijder said:
I'm not a rail junkie but is this a legal requirement or just the MBTA being overly cautious? There clearly isn't the same standard of safety for personal vehicles..
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I'd call on an expert to fact-check me here, but my understanding is that the stop signs on the GL preceding various steep declines are a remnant of when older (Boeing-made) trolleys had brake issues and needed that extra layer of cautionary action. The rail vehicles prompting this are no longer in service. I do not think it is a legal requirement that electric rail vehicles need brake-check stop signs such as this. I hope they will someday (soon) be removed from throughout our system.

On a separate unrelated note, I rode the Lechmere viaduct in both directions several times over the holiday weekend and can corroborate @RandomWalk 's observation: the speeds seem at 25mph both directions consistently. It is a huge difference!
 
Took the T in to North Station today. Nice and fast over the viaduct.
Kinda felt like some sort of project closure.
Also the train was packed at 8.30am.
Felt like it had been running for years.
Credit where it is due. It's beginning to be a great public transit service!
 
Ruairi said:
Took the T in to North Station today. Nice and fast over the viaduct.
Kinda felt like some sort of project closure.
Also the train was packed at 8.30am.
Felt like it had been running for years.
Credit where it is due. It's beginning to be a great public transit service!
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Love to read this kinda thing. I've enjoyed and frequently made use of the GLX since it opened, but I'll admit that's mostly because of the whole "something is better than nothing" angle, plus a fair degree of railfanning/train-geekdom on my part, but it's absolutely improved measurably of late.

Eng should be short-listed for "Person of the Year."
 
chrisbrat said:
Love to read this kinda thing. I've enjoyed and frequently made use of the GLX since it opened, but I'll admit that's mostly because of the whole "something is better than nothing" angle, plus a fair degree of railfanning/train-geekdom on my part, but it's absolutely improved measurably of late.

Eng should be short-listed for "Person of the Year."
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I’ve openly discussed with my family that I want to frame a portrait of Eng and hang it the living room.
 
GLX Track repair work loses out due to bad winter weather forecasts. Due to a winter storm forecasted on January 7th, work to repair tracks on the Green Line Extension would not be able to proceed on January 7th, 2024.

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