Green Line Extension to Medford & Union Sq

[Koopzilla24]

That seems like an @F-Line to Dudley question if there ever was one. But what I do know is that "safe" isn't a binary state -- there is always some risk, if nothing else at least from Acts of God/natural disasters. Some large fraction of managerial decisions are based on how long an organization is willing to endure a certain level of risk. So, for example, it could be that the narrow gauges do increase risk from a "normal level" (e.g. "risk of derailment is so low that it would take 100 years for one to happen randomly") to "something higher", but that "something higher" is still acceptable in the short term (e.g. "risk of derailment is so low that it would take 20 years for one to happen randomly").

That all being said, it does seem like a significant omission on the part of the Globe's interviewer to have (presumably) not asked that very obvious question. (This goes back to a problem I've had for a long time -- the Globe really does need to get some more industry-familiar reporters on this beat. Almost every article I've seen seems to lack very obvious follow-up questions.)

In a live streamed announcement by Eng a couple hours ago he stated that 56 1/8” is their minimum tolerance for being “restricted gauge” meaning it needs to be addressed. So the rails can be up to 3/8” too narrow before a speed restriction is imposed. The remaining ties must be somewhere within that tolerance but at risk of falling out of tolerance at any point. I would imagine that this is the point at which the way the specific wheel profiles of green line trains behave differently at design speeds on tracks.

MBTA's new Green Line Extension problems worse than reported, Eng reveals

Former Gov. Charlie Baker denied knowing about the problems with the Green Line Extension, which Eng says were first discovered in April 2021.

www.wgbh.org

Will this new set of repairs also cover the Lechmere Viaduct's 10 mph slowzone? 4 weeks of repairs on the Medford and Union Sq. branches, and previous repairs on the Lechmere viaduct, and the Lechmere viaduct is still one giant slowzone.

Last I heard about this the problem with the viaduct is that the Type 7s and 8s when paired and with two trains on it at the same time can weight too much to be safe when crossing. At higher speeds the bumps from non-continuously welded rails could exert excess forces on the structure.

 

[Koopzilla24]

For those interested in a more in-depth explanation about how train wheels interact with the rails the YouTube channel Practical Engineering just recently did a video about it. The video explains very well how rails that are too narrow could cause the train to ride on parts of the taper that it’s not designed for which can cause hunting oscillation or excess wear on train wheels and the rails.

 

[Teban54]

2 senior leaders of MBTA Green Line project fired after rail gauge fiasco

Two people with senior positions in the Green Line extension project were fired Thursday, a source tells 5 Investigates, as a new program manager was named to take over the troubled project.

www.wcvb.com

Two people with senior positions in the Green Line extension project were fired Thursday, a source tells 5 Investigates, as a new program manager was named to take over the troubled project.

Internal emails from December 2022 to top Green Line Extension leaders show more warnings about the Medford branch: "areas of URGENT NARROW GAGE" were discovered in nearly 30 locations and would require speed restrictions.

 

[Badusername]

Last I heard about this the problem with the viaduct is that the Type 7s and 8s when paired and with two trains on it at the same time can weight too much to be safe when crossing. At higher speeds the bumps from non-continuously welded rails could exert excess forces on the structure.

Where did you hear this? The last I heard it was due to them needing custom ties for the viaduct.

'Temporary' Green Line Slow Zone Approaches 1-Year Anniversary - Streetsblog Massachusetts

But in spite of all the work that’s been done on the Lechmere Viaduct, a “temporary” slow zone that has forced trains to run at a walking-pace crawl is now approaching its one-year anniversary.

mass.streetsblog.org

 

[Jahvon09]

2 senior leaders of MBTA Green Line project fired after rail gauge fiasco

Two people with senior positions in the Green Line extension project were fired Thursday, a source tells 5 Investigates, as a new program manager was named to take over the troubled project.

www.wcvb.com

This was probably mentioned in one of the latest developments on stories covering the debacles of the GLX.

 

[Jahvon09]

Here's even more troubling news about the troubled GLX, as if we haven't heard enough of it already!!

T suggests GLX rail ties manufactured incorrectly

THE MBTA says it intends to hold its contractor responsible for fixing rail ties placed too close together on the Green Line extension to Somerville and

commonwealthmagazine.org

 

[cubbe8]

Here's even more troubling news about the troubled GLX, as if we haven't heard enough of it already!!

T suggests GLX rail ties manufactured incorrectly

THE MBTA says it intends to hold its contractor responsible for fixing rail ties placed too close together on the Green Line extension to Somerville and

commonwealthmagazine.org

The wording is incorrect. It is the same news from before that the tracks need to be widened.

 

[Koopzilla24]

Where did you hear this? The last I heard it was due to them needing custom ties for the viaduct.

'Temporary' Green Line Slow Zone Approaches 1-Year Anniversary - Streetsblog Massachusetts

But in spite of all the work that’s been done on the Lechmere Viaduct, a “temporary” slow zone that has forced trains to run at a walking-pace crawl is now approaching its one-year anniversary.

mass.streetsblog.org

You’re right I completely forgot they actually did reenforce the structure last year. Doesn’t feel like that long ago. Time flies.

Documents from the Patrick administration listed the viaduct’s “steel section capacity” as 12 train cars, 6 on each track. So I wonder how often that situation was ever even encountered since at least the Boeing LRVs

 

[bakgwailo]

For those interested in a more in-depth explanation about how train wheels interact with the rails the YouTube channel Practical Engineering just recently did a video about it. The video explains very well how rails that are too narrow could cause the train to ride on parts of the taper that it’s not designed for which can cause hunting oscillation or excess wear on train wheels and the rails.

So that was the rational of rebuilding the viaduct with the GLX, as the structure could no longer support more than one train in each direction. If that is still the same limit post rebuilding then that is a huge wtf.

 

[Jahvon09]

The wording is incorrect. It is the same news from before that the tracks need to be widened.

But there was no mentioning that the wooden ties were incorrectly made before. But it's all coming out in the wash. This problem began with the then Baker administration, not with the Healey administration. Baker was letting things slide with the T, giving them breaks & babying them, I guess to ease the pain, to make HIM look good in front of the press! We only find this out long after the previous administration left that there were "cracks" in the GLX that should've been taken care of long before the public knew about it. Baker was putting on a false facade to make everyone think that nothing wrong was going on. And Poftak was no better.

 

[cubbe8]

But there was no mentioning that the wooden ties were incorrectly made before. But it's all coming out in the wash. This problem began with the then Baker administration, not with the Healey administration. Baker was letting things slide with the T, giving them breaks & babying them, I guess to ease the pain, to make HIM look good in front of the press! We only find this out long after the previous administration left that there were "cracks" in the GLX that should've been taken care of long before the public knew about it. Baker was putting on a false facade to make everyone think that nothing wrong was going on. And Poftak was no better.

The ties were not made incorrectly. It was the plates on the ties that were installed too close together.

 

[Mother Brook]

Why would this ever happen in the first place? I understand that it could shift over time, perhaps unpredictably, but it seems like installing track at a specific and standard gauge should be something that track building companies know how to do without a lot of fussing around. Would it come from rushing and skipping QA steps?

 

[real_EthanHunt]

This kind of outcome is unsurprising given how hard Baker was pushing to get it open before he took his lone walk.

Staying on schedule is now 'pushing'?
You really think the way this went was that 'upper management' found out and told the transportation secretary and the governor and were told to stand down?
You think 'upper management' are people that you've heard of before? These decisions were made by anonymous people that you have no idea who they are and it doesn't go any higher. That's why the T is in the state that they're in. It's generational at this point.

 

[ulrichomega]

But then shouldn’t the slow zones still exist?

Right? They slowed everything down for almost a month, apparently didn't fix the problem, and now things are fine again but we still need to fix it.

If I had to guess, I'd say that Eng discovered the issue and had everything slowed down for safety while inspections were made. Maybe there were some sections that needed immediate fixing and that took them up until they removed the slow zones. Now it's a whole thing to fix the rest of the line so there aren't any more issues. Maybe? I don't know, because even though I think Eng is doing a much better job at communicating, we're still in the dark on so much.

 

[737900er]

So that was the rational of rebuilding the viaduct with the GLX, as the structure could no longer support more than one train in each direction. If that is still the same limit post rebuilding then that is a huge wtf.

The Lechmere Viaduct has been closed for over 3 years since 2004, with two full closures lasting well over a year. There is no excuse that it's not in nearly defect-free condition.

 

[HenryAlan]

But then shouldn’t the slow zones still exist?

It's a subtle point in the article, but I think the slow zones were there only because an automated measurement triggered the requirement of slow zones until human inspections could be completed. The idea is that it's still possible to move safely on these rails, but rules required the slow down. As for the point about safely using them, clearly the belief is that the safety is fleeting and demands an immediate effort to fix the alignment.

 

[HenryAlan]

Wow, what a wild set of facts. Part of leadership is taking responsibility, and another part is firing idiots into the sun when they messed up before your time. There should be heads on pikes outside of every GLX station by sun up. Yeesh.

They did fire at least two people.

 

[Jahvon09]

The ties were not made incorrectly. It was the plates on the ties that were installed too close together.

Go back & read some of the news links, please. I'm done.

 

[Jahvon09]

Here's the story on the 2 senior leaders of the GLX that were let go. Click on the link below. GM Phillip Eng said that the repairs to the tracks won't take years or months, but it would take weeks. The amount of weeks is not yet given.

MSN

 

[Koopzilla24]

The Lechmere Viaduct has been closed for over 3 years since 2004, with two full closures lasting well over a year. There is no excuse that it's not in nearly defect-free condition.

From what I could find there was not much actual track or structural work done on the viaduct for any of the closures until the 2021 rehabilitation. In this most recent one the concrete arches were restored and strengthened, track deck and stringers replaced, signal cables replaced, catenary poles replaced, some track replaced, and finally replacing the power transmission cables.

The prior closures went as follows:

2004: Causeway Street Elevated demolished. Service suspended to Lechmere for the demolition period. New concrete ramp/incline constructed to connect to Science Park. Viaduct was closed for this period and track and signals were upgraded to increase speeds up from the existing 6-15mph restrictions to 20mph over the viaduct.*

2011: Science Park was closed for 8 months to be rebuilt into an accessible station. Viaduct was closed for this period with no real work being performed on it.

I’d assume that the 2005 repairs weren’t the most in-depth due to speeds only going up to 20mph instead of 25 and with not much change to the physical viaduct and track structures. This work was likely a simple track and stringer replacement of the worst sections.

This all furthers what you say of how ridiculous it is that more wasn’t done during these long closure periods. No excuses.


*the irony of the article from 2005 that this information came from is that it closes with optimism that further repairs would be completed with the soon to be constructed Green Line Extension to Medford