Red Line Extension to Mattapan

[TheRatmeister]

Just a reminder that the other option has not been proven to be viable either

I don't get why you're so hung up on proving things that don't need to be proven. The worst case scenario for a conversion is just the current routing but bored underground so you have a nice convenient work site and place to build ventilation shafts. There is no world, none, where building a new tunnel on the other side of the river but without the convenience of an already reserved ROW makes more sense. That's just how building things works.

 

[Scott]

There is no engineering study that says the current ROW is even possible. You know that so stop wondering. But a tunnel on the ROW could be an option but that is also unknown

 

[F-Line to Dudley]

There is no engineering study that says the current ROW is even possible. You know that so stop wondering. But a tunnel on the ROW could be an option but that is also unknown

Yes...there...is. As extensively discussed and which you keep ignoring, the Boston Transit Commission designed the ROW from Day 1 with conversion in mind.

 

[TheRatmeister]

There is no engineering study that says the current ROW is even possible.

The engineering work was done in the 1920s when they originally got the extension as far as Mattapan approved, and if you haven't noticed technology has advanced a little bit since the early 1900s, providing it doesn't require bending space or something you can pretty much build a railway wherever you want now. Here is the list of challenges that face any RL conversion, and their likely solution or solutions:

• Cemetery Embankment: Either strengthening the embankment or doing a capped cut tunnel
• Central Ave Grade Crossing: Either a bridge/overhang over the river or a bridge over the road
• Capen St crossing: Cutting/capped cut or bridge

None of those are particularly difficult to do. You are way, way, way more likely to run into political problems than engineering ones, which is why we were talking about the cemetery in the first place.

 

[Charlie_mta]

Sound wall technology has also advanced.

 

[Tallguy]

Serious question. Is there anything preventing a tunnel straight down Dot Ave from Ashmont to Milton, thus by-passing the cemetery?

Outrageous cost

 

[Jahvon09]

The MBTA will be getting new Type 10 long supercars to replace the present ones on the Green Line. When it does, it will be putting the new Type 9's in place of the old PCC trolleys on the Mattapan Line. At least, there will be ADA-compatible trolleys on the line, which there havn't been any at all!!!!

 

[Scott]

The engineering work was done in the 1920s when they originally got the extension as far as Mattapan approved, and if you haven't noticed technology has advanced a little bit since the early 1900s, providing it doesn't require bending space or something you can pretty much build a railway wherever you want now. Here is the list of challenges that face any RL conversion, and their likely solution or solutions:

• Cemetery Embankment: Either strengthening the embankment or doing a capped cut tunnel
• Central Ave Grade Crossing: Either a bridge/overhang over the river or a bridge over the road
• Capen St crossing: Cutting/capped cut or bridge

None of those are particularly difficult to do. You are way, way, way more likely to run into political problems than engineering ones, which is why we were talking about the cemetery in the first place.

I am sorry I missed this. I never said that I thought it wasn't possible or desirable. I just said that the measurements on a 100 year old document cannot possibly be valid today and you should be compelled to agree. There clearly needs to be a new study. Yes, the embankment would need to be strengthened and it would require making sure that all the burials in Cedar Grove Cemetery are where they are supposed to be because that isn't always the case in Boston with old cemeteries. I think a capped tunnel there would probably satisfy the neighbors concerns about noise. The Central Ave crossing would need to be done with some thought, so that it doesn't create a wall where there has been a historic divide between rich and poor, and black and white. A cut at Capen Street would undoubtedly be the best idea.

So then, where are they going to put the new stations? The walkshed to the current stations are part of the reason that it has such low ridership historically precluding any upgrade to heavy rail.

 

[TheRatmeister]

Wow, what a throwback.

I just said that the measurements on a 100 year old document cannot possibly be valid today and you should be compelled to agree. There clearly needs to be a new study

Of course. But engineers 100 years ago were not bumbling idiots and so we can have some level of confidence that the infrastructure was designed as they said it was. That's the difference between going into a study where the result seems like a 50/50, and one where the result seems like an 85/15. That's especially true given the recent reconstruction studies, where they verified that no reconstruction of the viaduct is necessary with the Type 9's AW3 (Crush capacity) axle load of ~22950 lbs. The maximum allowed weight at AW3 for Red Line trains as given in the 2013 RFP is 125,000lbs for an axle load of 31,250lbs, but I don't know what the actual weight of the 1900s is.

the embankment would need to be strengthened and it would require making sure that all the burials in Cedar Grove Cemetery are where they are supposed to be because that isn't always the case in Boston with old cemeteries.

Ceder Grove Cemetery isn't actually that old. The embankment came before the cemetery, not the other way around. That being said I can see some headstones have gotten very close to the embankment.

I think a capped tunnel there would probably satisfy the neighbors concerns about noise.

You don't get closer than ~400ft from homes until Butler station, and there are multiple layers of trees between them. I'm not overly concerned about noise there and if it is a problem you could always reduce the speed on that segment. It's also worth stating that the PCCs are hardly quiet as it is.

So then, where are they going to put the new stations? The walkshed to the current stations are part of the reason that it has such low ridership historically precluding any upgrade to heavy rail.

This is already a problem with the Type 9 reconstruction, and as per the last Mattapan Line meeting a review of possible closures and consolidations is ongoing. Valley Rd is very likely on the chopping block and frankly it deserves it. We can also be pretty sure that Capen St would be axed as part of any subway conversion. Central Ave/Milton, by far the busiest intermediate stops, are close enough to be consolidated for a subway station. It would probably be a couple minutes walking from either end to the street which isn't ideal, but I don't see a better solution. Cedar Grove/Butler are the most borderline but if they can be linked well enough to Ashmont/Milton respectively then I think they're reasonably safe to be eliminated. In any case, bus service could be used to supplement the new subway line for these cases.

 

[Scott]

A station ideally located could have a pedestrian bridge over the river, access to the Neponset Rail Trail, Dorchester Village, Milton Village, and the Central Ave areas of Milton and Mattapan. One actual Red Line station would be better than multiple trolley stops on the wrong side of the river

 

[JumboBuc]

So then, where are they going to put the new stations? The walkshed to the current stations are part of the reason that it has such low ridership historically precluding any upgrade to heavy rail.

I still think the best reference for this is Post #1 of this thread:

This popped up on my Twitter feed:

https://medium.com/@skyqrose/red-line-extension-to-mattapan-b7351aa782e

In the piece the author outlines how it might be beneficial to replace the high speed line with a simple extension of the Red Line. The MBTA is looking at what to do with the old light rail line especially in the wake of the recent crash. Knowing them they'd want to just pave it over and throw down BRT but a full heavy rail extension might be worth looking at.

• Keep Milton and Mattapan and close all the other ones.
• Turn the existing High-Speed Line viaduct from Ashmont to Cedar Grove into a pedestrian bridge, cutting down the walking distance between those two stations significantly.
• Build a new pedestrian bridge extension to tie Capen St into the existing network of elevated pedestrian bridges just east of Mattapan
• Butler and Central Ave are easy Neponset Trail walks from Milton
• This leaves only Valley Rd uncovered, but it has less ridership than a mid-tier bus stop.

 

[Scott]

My crazy transit pitch would be a station between Milton and Central, with entrances to both, that has a pick up/ drop off at Eliot Street on Milton Hill. The pedestrian bridge would cross the river approximately where the dam is now but is currently being removed, and hopefully it could have a connection to the supermarket and Washington Street. Otherwise the walkshed would not be any better