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> dates back to the late 1890s and will be replaced with a modern, more durable, metal trough.
I think any infrastructure that has lasted over 130 years is already quite durable.
It's wood, I'm sure the MBTA has a workshop that can build replacement parts.
Odds are the replacement is going to be some custom metal machined overseas and will be basically irreplaceable due to cost and skill issues.
The MBTA has a quite capable metal shop that's been making replacement parts for the 1960s vintage subway cars for quite a while.
Right but it will be something they can't work with. Like some custom magnesium-aluminum metal that has to be cast and can't be machined with normal tools.
And being the MBTA, it will be installed in the wrong size and have to be replaced in a couple of months.
My bet is on that there will be some kind of interaction of the metal catenary in the environment and maybe causing friction in the cables and shorts, which no one thought of since 1890 when they chose wood due for its insulating properties.
Then they will have to replace the metal with some fancy plastic one, because you can’t just admit the wood was better after all, but the plastic will also be unsuitable and degrade quickly which will ultimately end up with going back to wood in another 10 years. But that wood will then only last a fraction of the original wood, because we do not have old growth wood anymore and all the pine plantation wood won’t last a similar 130+ years.
So after about $3 billion dollars in costs and another $5 billion in economic and lifestyle impact after 20 years, they’ll declare it all a wonderful success, even though the wooden catenaries will live on as art or interior decor for another 200 years.
If we’re lucky, the death toll will even be low.
I foresee a "oh we can't replace the plastic one it with wood now because that would be a new material and we don't have data to prove it conforms with some rule we made up so the only solution is to pay some engineering firm who knows people on beacon hill a ton of money to say that pine is fine" situation before they go back to wood.
And as bad as the MBTA is... Keolis is worse (arguably).
Har, har, har, Buy Murican, amirite?
I encourage anybody who gets the opportunity to ride the green line. It's cool that they managed to build it in a time before tunnel boring machines (by literally digging a huge, long pit, building the track, then covering it with a roof and dirt again). Just wear noise cancelling headphones or something cuz those trains screech
Cut and cover is still the cheapest way to build subways, but is less often used nowadays because of the surface disruption.
Long before tunnel boring machines existed we needed to develop methods to dig under rivers. Brunel invented the tunnelling shield for digging under the Thames in 1825 and later a more refined version was used to dig the first deep-level tube line which opened in 1890.
THIS kind of comment is what makes HN gold!
TIL...
It's probably not the same wood since 1890. Requires more repairs and replacements.
I think there's a good chance it is. Not out in the sun, not in contact with ground/moisture, pretty consistent temperature. Wood can last a very long time under those conditions.
It could be. A lot of wood has been around for longer than that. Wood is easier to damage so I expect some has been replaced over the years, but there is no reason to think it wouldn't last in that application.
Yeah, I watch mine exploration videos and it's shocking how well wood in a dry and stable environment will last.
I wouldn't exactly call the environment on the green line as dry, especially in the summers.
The city of Venice is literally built upon timbers driven into the seafloor.
That haven't ever been replaced.
Maybe the chemicals they've used to treat the wood were so hardcore
Once again, promo-driven culture rears its ugly head.
Hold a chain at its ends, and let it hang down naturally. What is that shape called? A catenary and its equation is y = a cosh(x/a).
Maybe you all knew that factoid already, but I learned the name of shape only recently.
I actually did already know that factoid but was struggling (am still) to see how it relates to a wooden trough that merely holds cables.
Another interesting factoid about the catenary: Robert Hooke proved that it takes on the shape (though inverted) of the ideal arch, in terms of supporting loads above it. La Sagrada Familia in Barcelona is filled with them.
> but was struggling (am still) to see how it relates to a wooden trough that merely holds cables.
Overhead Catenary [1] is a standard term, for a system that has two wires overhead - one suspended from the posts (forming a series of catenary curve), the other suspended from that cable at regular intervals (and held level relative to the track). The wood in Boston's system seems to replace the catenary cable.
[1] https://en.wikipedia.org/wiki/Overhead_line#Overhead_catenar...
The Gateway Arch is an inverted catenary structure
https://www.nps.gov/jeff/planyourvisit/materials-and-techniq...
In a nutshell, the overhead power lines hang from their support points as catenary curves.
This is important to the design of trains, because you have to calculate the variance in height over the caternary length (highest at attachment point; lowest at somewhere near the middle, but depending on incline).
And efficiency of the line depends on the curvature so for a given target efficiency you can calculate how far apart the poles can be. For electrical lines I mean.
The part relevant to the editorialized headline:
“The MBTA will perform work in December to replace the wooden overhead catenary wire “trough” in the Green Line tunnel, which is original to the tunnel’s construction in the late 1890s. The trough houses the Green Line’s overhead wires and will be replaced with a modern, more durable, metal trough.”
San Fransisco looked at replacing their metal ladders with wood and decided to keep making the wood ones. Sometimes there's good reasons to keep the old material, the least of which is that metal conducts electricity. Unfortunately there's not many people left that can maintain it and it's probably cheaper to just keep ordering metal replacements. It still doesn't mean it's better.
https://sf-fire.org/our-organization/division-support-servic...
If only they’d make the T fare free and run more frequently and later into the night. The C line in Brookline has the potential to be extremely convenient, but at present most of the time it’s easier to take an Uber, or drive.
It's what, $2.40? I don't think they need to make it fare free.
Free fares would significantly increase ridership, no?
Probably not. For most people cost is not the issue of why they don't ride. Free would increase a little, but most people are not riding because the service isn't there. Service can be one of Frequency, speed, or ability to get to the destination.
Transit needs to: Get you from where you are, to where you want to be, when you want to go, in a reasonable amount of time, for a reasonable cost. If you lack any of those things and transit isn't useful. Generally cost is the only part of transit that is reasonable (but not always) and so it isn't something to focus on.
People who ask for free transit are really saying transit is for the poor and "normal people" should just drive.
Worse, free fares can cause undesirables to cluster and abuse the system.
Transit begin able to be paid with a phone has removed most or all the "friction" arguments, the need is to make it reliable (arrive on time) and frequent (so you don't have to meticulously plan your day).
> Free fares would significantly increase ridership, no?
It's not just about that. Higher transportation costs are heavily regressive. People with less money can't afford to live in the city and have to commute and then anything they pay to commute is independent of their wages, so $100 in fares is $100 whether you make $200k/year or $20k, whereas even the taxes like sales tax labeled as "regressive" would have the former person paying ten times more than the latter.
Moreover, fares are often heavily subsidized to begin with -- in large part because of the above -- but then not zeroing them out requires you to still pay the full cost of the collections infrastructure. Which is actually really expensive, because then you need turnstiles, payment processing equipment, security to prevent theft or card skimming, billing departments to deal with credit card fraud or chargebacks, customer service when people have problems, enforcement against people who skip the fare, etc. None of those costs go away if the fare is even $0.01, but they all disappear when it's actually zero.
And people who have never used it before then wouldn't have to figure out how to set it up, which is a significant source of friction independent of the fare and can cause people to just get an Uber (which they've already set up) or rent a car etc. Which causes people to never even try using mass transit, and then regard it as that thing they never use so why is the government spending money on it, instead of that thing that was convenient to use when their car was in the shop and made them realize that they can get by as a one-car household instead of two, or at least something worth supporting because they remember actually using it.
On top of that, removing the fares is better for privacy because then you're not tying your movement history to your payment card.
Speaking generally, free fairs also provide various benefits to a community such as reduced use of cars and easier access for lower income access to jobs and services.
you probably dont live in Boston, because there is no one on the planet that drives into boston rather than taking the T because its too expensive. people drive downtown and pay $40 for parking instead of taking the T.
Yes, and reduce its revenue that it needs to properly run and upgrade its existing infrastructure.
Why do you think they charge in the first palce?
Rider fair is only one way to fund transit. My city (Corvallis, OR) provides free bus service city wide since 2011. The newest addition is free bus service to surrounding cities (up to McMinville and down to Eugene).
It's paid for with state and federal grants, university (OSU) contribution, as well as a utility fee.
Because governments aren't allowed to simply provide services for free anymore. It is inconceivable that something like moving around on mass transit would be free at point of use.
I haven't been there in a while. Is one of the four bars in Brookline now open past 8PM or something?
There are a few, but they are trying to fix that since no one stays up that late.
The Abbey is often buzzing until 2am. Food served after midnight, too.
the MBTA already absolutely bleeds an incredible amount of money. No businesses in Boston are even open late, theres no night life. 90% of the young people in the city are nerds doing Phds.
I loved living right on the red line, but its just not worth it unless we figure out how to make it not cost a fortune.
Why does it have to make money? We don't ever expect the welfare department to suddenly turn a profit, do we?
It's been a decade+ since I used to catch the Green line at Park St, but at that time it was the noisiest, squealiest station that I regularly used. Not surprising to learn that parts of that station are left over from the 1890s.
It's deafening
The builders should be patting themselves on the back. The fact that some of this infrastructure was built in the 1890s is amazing.
I really like those service diagrams to show which stations are closed and how to get around them.
Boston subway to replace cable duct that worked for 130+ years