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Old 05-20-2019, 07:55 AM   #3521
ulrichomega
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Re: Crazy Transit Pitches

Quote:
Originally Posted by F-Line to Dudley View Post
If they pick up Transitway-Downtown for re-study as LRT, they'll work up the Essex St. Alternative again simply because that was the best-studied one when it was Silver Line Phase III. But its chances are not good because of the expense incurred by structurally underpinning Boylston Station and Chinatown Station (with a double-decker Silver platform, making it 3 stories deep!!!), and the mitigation costs incurred by the digging under very narrow Essex.

The killer flaws that need to be corrected to net a cost estimate that's actually buildable are:
  • Fewest structural underpins possible. Offset, rather than stacked, stations.
  • Fewer touches of old infrastructure. 20th c. widened streets, 1960's urban renewal property >>> "Old Boston" 19th c. buildings + poorly documented utilities.
  • Less duplication of infrastructure. Re-use outer Boylston platforms + some/all of Tremont tunnel instead of building twice, resorting to ham-fisted geometry to make transfers.
That probably means you're doing a South End jog, hitting Orange-Tufts Med. Ctr. with a connecting concourse, and looking for wide and/or urban renewal streets (Kneeland, Marginal...more than one way to try it). Then hitting the pre-provisioned trajectory into the Transitway at the north tip of Chinatown Park. And keep in mind: as BRT the Essex tunnel was to be so godawful dog slow that nearly all service would be forced to loop from either side at Boylston for dispatching sanity. So a trolley on fixed track is going to make this trip faster than SL Phase III ever would've even if the path is no longer straight as the crow flies and looks underwhelmingly indirect on a 2D map. SL Phase III would've been way, way worse than the Transitway crawl.
There are two broad options for connecting the Transitway to the Green Line system as a whole: Either you connect from Park St or you connect from Kenmore (let's ignore a new E line trunk for now). the south side, in my opinion, has far more capacity to give than anything routed through Park St. Given the narrow street geometry near Boylston, I don't see any sort of track curve happening to bring anything from Kenmore down south to reconnect to the Tremont subway. Far better, in my mind, to simply follow Van's suggestion of using the widened tunnel near Arlington to bury a new tunnel under Boylston and Chinatown. The costs are high, yes, but if it means actually being able to feed the Seaport rather than sacrificing overall system capacity I think it's worth it.

Quote:
It's less about having a "favorite" routing than maximizing the build odds...because we should've already had this but those bulleted pitfalls above torpedoed the cost. It's a billions-dollar project, but we want a "buildable" digit stuck onto the front.
As above, think efficiency + minimal pitfalls to lift up the Seaport connection to the realm of buildability. Tremont tunnel is 4 tracks...right there you've got grade separation for 2 branches. Can you utilize 2 tracks for the Seaport branch and 2 tracks for the Dudley branch? Or can you plow that 4-track tunnel past Tufts station down Tremont, set up 2 of the tracks to go to the Seaport + Dudley, and leave a 2-track stub to continue west as the "new" E to Back Bay + Prudential. Such that the Huntington tunnel eventually gets extended to become an "alt. spine".
Now let's bring back the new E-Trunk. This new tunnel gives us another way of reaching the Seaport from the south: merely continue the tunnel forward with a wye where you would otherwise turn to hit Boylston. This lets you route traffic from the north and south into the Seaport. I like it as a solution, and will probably integrate it into future thoughts. Under this system you'd essentially be trading one E-Trunk branch for a Seaport branch at Park St.

For the record, I was considering one of the two tracks to continue west under Stuart or Marginal, and dedicate the other to Seaport/Dudley traffic.

Quote:
As in my last reply, that's way way too many northern branches to dispatch...and the fact that the non-UR additions are subject to the chaos of hard-to-control grade crossings offset too far from nearest traffic lights means schedule dominoes are going to start falling regularly.
Look again at the map. Only three lines are actually going into Lechmere from the north. There's a bit of dispatching trouble possible at the new maintenance yards, but at no point would more than three lines ever be sharing tracks:
  • Urban Ring, Malden to Downtown, Malden to Kendall across the bridge into Sullivan
  • Medford Branch, Porter Branch, Malden to Downtown through Lechmere into Downtown.
  • Porter Branch, Malden to Kendall and Urban Ring along a short stretch between the maintenance yards and where the Grand Junction splits off.

Now, that's a lot of line interweaving but there's no point at which it becomes a crisis, especially given that two of the lines are completely traffic separated.

Quote:
The Cambridge Ring is absolutely positively essential. Kenmore is the tie-in destination, because the south-half Ring that's going to have to be BRT originates there. Filet service between the Kenmore circuit and Harvard Branch as suitable, but anyone waiting on the westbound platform at Kendall surface station must be able to hit Kenmore on at least every other train. Bio-metropolis over in Cambridge needs to be able to pick up a quick transfer to Longwood; that shouldn't even be a question.
How is traffic getting routed at Kenmore then? If it's continuing straight into Back Bay then I don't see the point of any of it. At what point does someone get on the train along the Urban ring to go all the way through Kendall and BU just to get to Park St? If the traffic is bounding back out along the C or D, then reconfiguring the tracks is going to be a monster to allow that. And if we're bounding back out along the B then Kenmore is a terminal station on the Urban Ring? That seems reasonable, but I'd be worried about trains sitting on active B platforms.


Quote:
Watertown's pretty straightforward. It'd be about 3/4 mile of street-running (though perhaps with reservation'ed platforms) on Arsenal St. at the very tail end...not enough length to kill an inbound schedule to Lechmere. But other than that the routing is very direct and structurally simple (2 shallow duck-unders of Sherman St. and Fresh Pond Pkwy. being the most concrete poured). On cost and buildability it's a good one. It's just not as mission-critical as the biggies. We REALLY REALLY need the Seaport connection, the NW+NE Ring quadrants, Dudley streetcar, the Porter transfer, Needham (for all the well-documented RER-driven reasons), and the E Back Bay relocation. Watertown just doesn't have any oxygen when that's the five-alarm needs list.
Hence why I didn't include it. There's a dozen ways out from there, all of them reasonably priced and of reasonable ridership to alleviate Red Line congestion at the end, but none of them that are of high importance.

Also, I start to get nervous extending any line out from there too far. You quickly start looping back on yourself over absurdly long dispatch distances if you send D or E out there, which you have to if you want to maintain branches as traffic separated.

Quote:
As I said, that's just too many northern branches. And that's a bad thing if the extras exert any destabilizing effect on a load-bearing branch like the Urban Ring segments. Or Medford, for that matter...that one's got insane potential to completely blow its projections out of the water and require more service. And you can't do much more than is already going up. Lechmere is a pretty snug fit across the street, so there isn't a turnback until Brattle Loop. The problem with having crossing-heavy branches added to the 2 grade separated GLX's and the 2 very nearly grade separated Ring routes is that if one of these extra builds stubs its toes in crossing traffic in Malden it's already started dragging the rest down for several stops before it ever gets the chance to dump out at Brattle. And that's doubly ungood for whatever other branches are running at much denser frequencies when they get tripped up (like two 3-min. headway 3-car trains becoming late because of a 6-min. headway 2-car train, and relative numbers of riders impacted).
I absolutely agree that keeping completely traffic-separated branches apart from non-separated branches is critical, but I don't see any way to really do that unless we're limiting ourselves to two northside branches for all time (or biting the bullet and picking out new downtown tunnel locations. An alternative is to send all of the Urban Ring/Malden branches down the Grand Junction, but I don't think that riders there are going to love needing to make odd transfers to get downtown.
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Old 05-20-2019, 09:28 AM   #3522
Tallguy
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Re: Crazy Transit Pitches

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Originally Posted by F-Line to Dudley View Post
I would posit finding some evidence to back up such a bold statement, but I know that ship has sailed. In your mind, this is modal warfare: anything on steel wheels is better than anything on rubber tires, regardless of the service offered. I'm asking what is it about a such a convoluted routing, with so many conditions levied on it (Orange-Reading, reworking a large chunk of Orange, reconstructing 1.5 miles of a state parkway for a reservation, ROW acquisition beside an Interstate highway) to function at all, that makes it good TRANSIT. Ditto your 6th GL-north branch to Saugus with all its own traffic impacts, and how you're going to integrate two brittle schedules into the Green Line without gumming up Union, Medford, UR NW, and UR NE at the Brickbottom merge.

One is an argument of intensity-of-belief, one is an argument of facts and empirical comparison with other routes. I think you need to account for why no other routes in the area choose such pretzeled routings and how systemwide--all-modes--the twisted routings fare in relation to more direct routes. On the evidence that clearly is not so strong a rider behavior characteristic as you're assuming it is. I think you need to account for the feasibility of any project with so many separate prerequisite builds if it is to exist at all, and how you're ever going to stage so many separate builds in separate jurisdictions to...make...it...all...so. How much is Orange-Reading going to cost and how many years will it take to even give you any path at all to the Medford Branch and Saugus Branch before spending another load to rework a 2.5 mi. stretch of Orange ROW? How is it the mere existence of steel wheels that makes Fellsway a more viable transit route when that's contingent on MassHighway spending 9 figures separately to rip the everloving crap out of the roadway to radically compact it and make a reservation. How can any planner expect to just wave those things off as foregone conclusions??? And since we're talking modes, why is bus congestion and troubleshooting therein so stinky-poo while there is no consideration whatsoever being given to the network effects of merging SIX branches at Brickbottom. We point fingers all the time at Kenmore's 3 branches and the future mitigation that's needed there to pare back "garbage-in/garbage-out" from the B and C. But are the chaos effects of mixed-traffic running under street signals somehow not a concern at Brickbottom because of the magic of steel wheels on Fellsway and all those askew Saugus Branch crossings???


I've been through enough of these arguments on AB to know that you cannot argue rationally with pure intensity-of-belief, and you will never convince someone deep in the modal warfare trenches that flawed transit is flawed transit is flawed transit. Their choice of vehicle is already the hammer looking for every nail: nothing more needs to be considered because "_RT = voila!", project flaws don't need to be corrected because of "Y mode sux!" irrelevance and near-religious belief that their mode choice is self-correcting, and every prospective rider believes exactly the same as they do.

Been there, done that. Too many times. Believe what you want to believe, but on the merits these are deeply flawed proposals that assume way too much about their project areas, prerequisite infrastructure, system integration, and rider behavior. All that stuff doesn't get waved away because you believe harder in it than the next person.
Ah, I was wondering how long it would take the see the "modal warfare" epithet!

Here is what I have observed, not "believe".

1. That transport moves best on a dedicated, grade crossing free ROW.
Barring that, a dedicated ROW with minimal crossing is next best.
That a dedicated steet running lane is more desirable.
2. That one seat rides draw the most, even in cases where it might result in a moderately longer trip.
3. That HRT can carry more people than LRT, which can carry more people than buses.
4. That Boston's roads are clogged and are only going to get worse.
5. That BRT operations require the kind of roads that we have few of.
6. That, within financial reason,it is easier to adapt to human nature than it is to try to change it
7. That real estate prices and development make my points.


While I admire the progress that the Everett and Washington St. bus lanes have brought to transit solution discussions, they are not enough. Let a thousand bus lanes bloom! We still need to extend the Orange Line to West Roxbury. We still need to do more to provide transit equity to Everett, Chelsea and Mattapan. BRT Light will help., but full development of Fairmont Line, Green Line UR over the Mystic River and RER to Salem should still be the goal.
But maybe rich people deserve steel wheels and poor people should just make due with rubber tires........

Does that make me a modal warrior? Strange argument from a person whose screenname advocates for replacement of buses with street-running trolleys. ....

But consistancy does not seem a hallmark of your reasoning. You advocate a circuitous route from Watertown to downtown by Green Line, but condemn me forthe same. You blithely wave off the nightmare that contructing a trench across Rt 2 would be. You also calmly dismiss the effects of 3/4 mile of street-running on Arsenal, a major artery, would have on Brickbottom branch merging, but condemn my Medford and Saugus proposals for their impact. You try to equate the 25-30 street-crossing nightmare of the B and C lines with the 5 crossings of Medford and while Saugus has 14-9 crossings, the route is MUCH less congested(one crossing services a dozen houses, a lorise apt building and a small business.

I did not wait over a year for the right to post to get into a flame war, but I will not abide inconsistent argumentation or ad hominem attacks either.

BTW, F-Line, I checked this mornings travel times from Medford Center this AM, as I did several times before I suggested the route. All the options were longer and only one was one ride, the express to Haymarket (which might still require a transfer ifyou are going anywhere but Haymarket. This is called research, not "intensity-of-belief".

Last edited by Tallguy; 05-20-2019 at 09:39 AM.
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Old 05-20-2019, 09:52 AM   #3523
Tallguy
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Re: Crazy Transit Pitches

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Originally Posted by ulrichomega View Post
There are two broad options for connecting the Transitway to the Green Line system as a whole: Either you connect from Park St or you connect from Kenmore (let's ignore a new E line trunk for now). the south side, in my opinion, has far more capacity to give than anything routed through Park St. Given the narrow street geometry near Boylston, I don't see any sort of track curve happening to bring anything from Kenmore down south to reconnect to the Tremont subway. Far better, in my mind, to simply follow Van's suggestion of using the widened tunnel near Arlington to bury a new tunnel under Boylston and Chinatown. The costs are high, yes, but if it means actually being able to feed the Seaport rather than sacrificing overall system capacity I think it's worth it.



Now let's bring back the new E-Trunk. This new tunnel gives us another way of reaching the Seaport from the south: merely continue the tunnel forward with a wye where you would otherwise turn to hit Boylston. This lets you route traffic from the north and south into the Seaport. I like it as a solution, and will probably integrate it into future thoughts. Under this system you'd essentially be trading one E-Trunk branch for a Seaport branch at Park St.

For the record, I was considering one of the two tracks to continue west under Stuart or Marginal, and dedicate the other to Seaport/Dudley traffic.



Look again at the map. Only three lines are actually going into Lechmere from the north. There's a bit of dispatching trouble possible at the new maintenance yards, but at no point would more than three lines ever be sharing tracks:
  • Urban Ring, Malden to Downtown, Malden to Kendall across the bridge into Sullivan
  • Medford Branch, Porter Branch, Malden to Downtown through Lechmere into Downtown.
  • Porter Branch, Malden to Kendall and Urban Ring along a short stretch between the maintenance yards and where the Grand Junction splits off.

Now, that's a lot of line interweaving but there's no point at which it becomes a crisis, especially given that two of the lines are completely traffic separated.



How is traffic getting routed at Kenmore then? If it's continuing straight into Back Bay then I don't see the point of any of it. At what point does someone get on the train along the Urban ring to go all the way through Kendall and BU just to get to Park St? If the traffic is bounding back out along the C or D, then reconfiguring the tracks is going to be a monster to allow that. And if we're bounding back out along the B then Kenmore is a terminal station on the Urban Ring? That seems reasonable, but I'd be worried about trains sitting on active B platforms.




Hence why I didn't include it. There's a dozen ways out from there, all of them reasonably priced and of reasonable ridership to alleviate Red Line congestion at the end, but none of them that are of high importance.

Also, I start to get nervous extending any line out from there too far. You quickly start looping back on yourself over absurdly long dispatch distances if you send D or E out there, which you have to if you want to maintain branches as traffic separated.



I absolutely agree that keeping completely traffic-separated branches apart from non-separated branches is critical, but I don't see any way to really do that unless we're limiting ourselves to two northside branches for all time (or biting the bullet and picking out new downtown tunnel locations. An alternative is to send all of the Urban Ring/Malden branches down the Grand Junction, but I don't think that riders there are going to love needing to make odd transfers to get downtown.
If UR stayed UR and did not try to go downtown, both Sullivan(from the north) and the presumed Inner Belt station on the UR(from the south) should be easy same platform transfers to Medford or Saugus. So, three branches feed Lechmere not six.
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Old 05-20-2019, 12:59 PM   #3524
dmdogs900
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Re: Crazy Transit Pitches

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Yikes. It's about 30 miles between Northampton and the nearest passing of the App Trail, with some rough terrain in-between. I seriously doubt it. The B&A and Fitchburg Main were the only two RR's ever chartered that passed through the border of Berkshire County to any of the neighboring counties to the east...so there aren't any unused RR ROW's available at all. Nor is rail-with-trail a possibility on those two hugely busy freight lines, as some of the cuts/fills/ledges done through tricky terrain are no wider than the in-use trackbed. There may be a maze-like spaghetti map of hiking trails available that span much of the distance, but you'd be talking very circuitous routes, unmaintained surfaces, and a lot of grades so steep a complete trip by mountain bike would be out of the question...and possibly some climbing gear required.


Central Mass trail is also far from finished. Between Clinton and Belchertown the RR was abandoned in pieces between 1933-38, so property acquisition is a bear. Most of what's trailed or planned for trail is on the MBTA-owned section Waltham to Hudson, the Mass Water Resources Authority-owned section around Wachusett Reservoir, and the Northampton-Belchertown section spanning the Conn River Line and NECR mainline (re-named the Wheelwright Branch after the mainline was severed in the middle) abandoned by B&M in 1979. The roadbed on the Depression-era abandonment is remarkably unencroached after all this time, but there's still huge amounts of legal work to do before they can span Worcester County with a connecting trail between T territory and the Wheelwright Branch.
I think it can be connected to the new England trail, from there can it be connected to the appalachian Trail?
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Old 05-21-2019, 07:29 AM   #3525
ulrichomega
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Re: Crazy Transit Pitches

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Originally Posted by Tallguy View Post
If UR stayed UR and did not try to go downtown, both Sullivan(from the north) and the presumed Inner Belt station on the UR(from the south) should be easy same platform transfers to Medford or Saugus. So, three branches feed Lechmere not six.
Exactly. Lechmere is a chokepoint, but with the Grand Junction switched to Light Rail we have a convenient outlet for a lot of traffic from the Sullivan direction. Also given how much of a job center Kendall is I think direct service there from points north would do a lot to alleviate congestion on the Orange Line and the downtown transfers.
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Old 05-21-2019, 01:08 PM   #3526
Tallguy
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Re: Crazy Transit Pitches

Has anyone seen cost estimates for a bridge over the Mystic for a pair of LRT tracks? I know a ped bridge has been discussed....
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Old 05-21-2019, 05:45 PM   #3527
F-Line to Dudley
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Re: Crazy Transit Pitches

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Has anyone seen cost estimates for a bridge over the Mystic for a pair of LRT tracks? I know a ped bridge has been discussed....
Doesn't exist. Urban Ring Phase II was never studied in enough depth to itemize any costs by component, and hasn't been revisited in a dozen years now.

You would first have to re-study to even figure out WHAT kind of bridge you were building. UR has to go on the west side of the Eastern Route tracks to steer clear of the Everett Terminal freight turnout. That means that the most logical bridge option would be repurposing the 1988 RR bridge for the UR and instead building a new RR bridge on the alignment of the old Eastern Route drawbridge...at half the length of the '88 span...to shift the Eastern Route onto. But if that's not doable you're probably building a new one to the north that's a few hundred feet longer than the '88 span.

How can you possibly peg an itemization without doing a new study to affirm even a tentative preference? It's unknowable, because we don't know by factor of half how long a new bridge will need to be.
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Old 05-22-2019, 07:17 AM   #3528
mass88
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Re: Crazy Transit Pitches

How unrealistic would it be to double track every commuter rail line? And then triple or quadruple tack the 5 or 6 busiest lines to allow express trains? Would doing this make any tangible difference in terms of speed and reliability of the commuter rail?
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Old 05-22-2019, 07:46 AM   #3529
sneijder
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Re: Crazy Transit Pitches

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Originally Posted by mass88 View Post
How unrealistic would it be to double track every commuter rail line? And then triple or quadruple tack the 5 or 6 busiest lines to allow express trains? Would doing this make any tangible difference in terms of speed and reliability of the commuter rail?
I think it ranges from easy (add retaining walls and lay track) for Needham to damn near impossible (Old Colony pinch). NYC has shown that you can run an absurd amount of service well dispatched across two tracks. I think two tracks should suffice for almost all express/local service in the network, maybe save the NEC.
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Old 05-22-2019, 10:14 AM   #3530
Tallguy
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Re: Crazy Transit Pitches

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Originally Posted by F-Line to Dudley View Post
Doesn't exist. Urban Ring Phase II was never studied in enough depth to itemize any costs by component, and hasn't been revisited in a dozen years now.

You would first have to re-study to even figure out WHAT kind of bridge you were building. UR has to go on the west side of the Eastern Route tracks to steer clear of the Everett Terminal freight turnout. That means that the most logical bridge option would be repurposing the 1988 RR bridge for the UR and instead building a new RR bridge on the alignment of the old Eastern Route drawbridge...at half the length of the '88 span...to shift the Eastern Route onto. But if that's not doable you're probably building a new one to the north that's a few hundred feet longer than the '88 span.

How can you possibly peg an itemization without doing a new study to affirm even a tentative preference? It's unknowable, because we don't know by factor of half how long a new bridge will need to be.
Thank you, F Line, for telling me that YOU are not aware of anyone, say Wynn Resorts, who has looked into it. They have thrown money around like a drunken sailor. Perhaps someone else has. Hence my query.
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Old 05-22-2019, 10:37 AM   #3531
HenryAlan
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Re: Crazy Transit Pitches

Well aside from Wynn and the secret study by the Eater Bunny, publicly available data doesn't exist, so....
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Old 05-22-2019, 12:52 PM   #3532
Tallguy
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Re: Crazy Transit Pitches

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Originally Posted by HenryAlan View Post
Well aside from Wynn and the secret study by the Eater Bunny, publicly available data doesn't exist, so....
Again, another polite, useful comment. Is this forum here to take potshots at each other or to discuss transit? I asked a polite question. So far, I've gotten two snide comments.
I don't proport to know everything about everything, and neither should either of you.
And btw, Santa did the secret report, not the Bunny
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Old 05-22-2019, 01:16 PM   #3533
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Re: Crazy Transit Pitches

Surely the bigger cost for Light Rail in that direction is going to be the complete retooling of Sullivan station? You need to make room for an Orange Line platform, at least one Commuter Rail platform (maybe more depending on how we're redoing the Haverhill line's connection here) and a Green Line platform. All of this under a major roadway. It looks like there's physically room to spread out in there, but the supports for the highway surely weren't built with this in mind and will have to be redone.
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Old 05-22-2019, 02:50 PM   #3534
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Re: Crazy Transit Pitches

So right now, there are seven tracks and two platforms @Sullivan: (from east to west)2 CR, the unused OL express track, an island platform OL, island platform, OL, and two empty spurs up from Brickbottom. The two lines could be separated enough for a platform AFAIK, so, whith some kind of connection over the tracks, you could do it. As far as the CR, it depends on how badly you want to preserve the unused express track. If (big if)you can connect that line to the western CR without running into a highway pylon, that means you could have space for a platform for the eastern track. If not, then you could build a new platform over the OL express and either blow out the station wall ( no idea whats on the other side) and or run the platform offset to the north.

Last edited by Tallguy; 05-26-2019 at 05:36 AM.
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Old 05-23-2019, 06:03 AM   #3535
F-Line to Dudley
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Re: Crazy Transit Pitches

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Originally Posted by mass88 View Post
How unrealistic would it be to double track every commuter rail line? And then triple or quadruple tack the 5 or 6 busiest lines to allow express trains? Would doing this make any tangible difference in terms of speed and reliability of the commuter rail?
It's not necessary, because capacity doesn't really match 1:1 with number of tracks.

Background. . .

In the old days of steam, 1840-1950, block signaling was fairly primitive and RR tracks were signaled mostly unidirectional. This was because:
  • Steam locomotives were unidirectional and had to be turned around at wyes, loops, or a turntable. No such thing as passenger push-pull or freight cab-backward running, except with early electrics.
  • The RR was mechanically dispatched from employees in lineside towers every umpteen miles pulling levers on a mechanical switchboard while reading a telegraph feed. The only way to keep it sane was to segregate track directions over-rigidly.
  • Trains could run "wrong rail" if they absolutely had to for reaching a siding or junction, but it was kludgy at best and required extra cautions that gummed up traffic in the other direction.
  • Track switching was primitive until switch motors were perfected, so throwing a crossover switch either required a human switch tender in the field (usually practical only at staffed stations or very busy spots), or complicated pneumatic machinery to auto-throw a switch.
Consequently, the only single-track lines in existence were short low-traffic branches and very ends of lines where "track occupancy" rules (i.e. one train holds total control of the entire territory until it either leaves the territory or safely ties down on a siding) were enough. Very busy lines like the innermost NEC, B&A, Old Colony, and Western Route were all tri- or quad-tracked because the scarcity of crossovers meant there had to be express + local tracks in each direction for express of skip-stop overtakes.

After WWII things were significantly modernized with bi-directional diesels, and what's called Centralized Traffic Control (CTC) signaling which consolidated all those manual field towers (last one on the T: Waltham Tower controlling Fitchburg Line, retired 2011) in favor of massively centralized and heavily automated master controls. The T has the whole northside and whole southside under centralized dispatch offices...and CSX, for example, dispatches close to 100K miles of its whole east-of-Mississippi route network out of some giant operations bunker down South. With that centralization the lines were updated with full bi-directional signaling and a crapton more automatic switches so no human had to physically touch traffic.

The upshot was that the extra tracks were no longer needed. Dispatch now had the whole 'big-picture' railroad at its fingertips instead of having to play telephone with a bunch of field towers, automated crossovers were way more numerous, and the signals (including widespread deployment of stop-enforcing cab signals) were much safer and more precise for staging close train meets. A well-designed 2-track line would have MORE raw capacity than the 4-track express+local line of old that could only do brute-force overtakes. And the single-track line with very well-placed passing sidings corresponding to scheduled meets could fare just as well as a double-track line. So the RR's, which were flailing around in bankruptcy by the 50's and 60's, ripped out most of their extra trackage...some haphazardly, some judiciously. Quad-track really only remained on the NEC where passenger traffic New Haven-south remained too insanely dense (even during the ridership famine era) to mess with. That's also when all of the non-passenger branchlines that were still human/tower-controlled had their signals retired and went dark (local examples: Cape Cod mainline, Framingham Secondary, Fitchburg Secondary, Peabody Branch, Fall River & New Bedford Branches + pre-restoration Middleboro & Plymouth).

-----------------------------------

What does it mean today?
  • A lot of the remaining single-track needs to be backfilled back to double due to changing traffic levels.
    • They obviously re-doubled the Haverhill Line between Wilmington and Lawrence because the cuts to single were too severe 50 years ago.
    • Franklin has a funded package starting construction soon for DT spanning the long stretch between Walpole and Norfolk stations so train meets are less brittle. It'll get a little bit more between Norwood Central and Windsor Gardens if Foxboro full-time service comes to pass.
    • Worcester got the Beacon Park constriction filled, and is funded for Worcester Union Station to get a second platform track. That will make it the only line other than NEC & Lowell that are unbroken DT end-to-end.
    • Fairmount's due to get its Readville platform located off the single-track connector so it can host intended service levels on a double-track full-high island. That would make Fairmount the 4th line to be unbroken end-to-end DT.
  • RER will require a systemwide audit on where additional double-track is needed.
    • Wildcat Branch will probably need to be doubled up if Haverhill trains are being moved out there.
    • Reading Line Urban Rail requires Reading Jct. in Somerville to be doubled, the Wellington passing siding to be upgraded, and Reading Station-proper to be doubled. The unexpandable Medford-Malden single-track along the Orange Line is OK so long as long-haul service to Haverhill vacates.
    • Newburyport Branch will need most (maybe not 100%) of its remaining single backfilled.


That said, some places can probably suffice as single-track for a very long time.
  • Old Colony branches. Obviously until you spend megabucks to fix the Dorchester-Quincy pinch there's not enough traffic that can get through to merit unbroken DT. You'll just be adjusting the lengths of the passing sidings if scheduled meets change.
  • Needham. Same reason; service levels can't physically increase because of SW Corridor congestion, so no point. The only contiguous DT it'll ever see is from Orange & Green.
  • Gloucester-Rockport and Franklin-Forge Park. Arse ends of the line, so even at RER :30 levels trains clear the single track without problems. At most, Gloucester Station-proper and Franklin Station-proper could use a doubling-up instead of the double cutting out right before the stops...but it won't be needed on the running track between there and the terminal stops.
  • Extremely short single-track exceptions. Examples:
    • There's a practical reason why the Fairmount-Franklin connector is a single-track bridge that wasn't doubled-up. That short stretch spans "Readville Upper" and "Readville Lower" junctions, where the sheer complexity of the switches makes it operationally easier to stage as single rather than double. It's too short a stretch to affect ANY :30 or :15 headway on Fairmount, Foxboro, or Forge Park so is a non-issue.
    • There may have to be a short stretch of single in the middle between Windsor Gardens and Walpole, because there's a narrow historic tunnel under a block of Walpole streets that would prevent side emergency exit from a stalled train if it went back to DT.
    • Junctions: Wildcat Branch split from Lowell Line immediately crosses a grade crossing; no problem if it doesn't fan out to DT until after the crossing. Ditto the Middleboro/Plymouth split because both feed immediately into crossovers at Braintree Station and switches for 2 x 2 splits are maintenance-intensive.


For MORE than 2 tracks. . .

Basically nowhere except the NEC. And that's for one very specific reason: speed differential, not express vs. local. Even though you have a pretty dense layer cake of services envisioned for Worcester and even Lowell...with increased Amtrak presence bouncing around in there...all traffic is moving at more or less the same top speed. A well-designed crossover layout is what makes it happen.

So for example:
  • Most Worcester service is going to be skipping through Allston-Newton like today and picking up only the occasional stop. It's the only way to keep sane travel times. On Amtrak, Framingham's the first stop for a Lake Shore Ltd. or an Inland Route train, so their needs for skipping over the Urban Rail Riverside locals are exactly the same as most Worcester schedules. One track layout between Yawkey and Riverside Jct. handles all meets.
  • After the Riverside trains have dropped off, it's only Amtrak and some super-expresses that have to leapfrog anything in Wellesley and Natick. Fewer crossovers necessary for juggling that traffic, so there's more flex to add them if Amtrak's and T skip-stop's needs start to diverge.
  • After Framingham, it's just Worcester and Amtrak. Other MetroWest locals have all dropped off. And Worcester is making the local stops everywhere except maybe on some future Heart-to-Hub schedule where they're making the same skips as Amtrak. It's pretty much crossovers for Amtrak.
^^Unless you raise the top speed >80 MPH, which will take some work, the meets happen pretty much the same spots whether they're Amtrak>T or T>T. It's mercifully straightforward. Things would be slightly different if Amtrak could rev it up to 90 MPH, because then the meets wouldn't be happening at the same crossovers and you'd need a more complex railroad. But in no practical sense is there anything here calling out for 3 tracks.

Now, you DO have places for 3-track passers: West-Boston Landing where it actually exists, the new Natick station which leaves a provision, and possibly a sorting stretch between Riverside Jct. across 128 if it's necessary for resetting the order after the Urban Rail trains turn out. Likewise, the Framingham and Westborough freight yard leads space out *possible* passing opportunities to the west if traffic ever gets hectic enough. But I would not consider any of those available lengths of triple necessities; some are just easy-grab luxuries because they're already present. Those wouldn't be needed for base-build RER. That's more for when you've got RER, NSRL, max-expansion Amtrak schedules, Framingham-Northborough branch service, and a couple decades of mind-blowing growth on the whole lot of them.


Q: WHY IS THE NEC DIFFERENT?
A: THE NEED FOR SPEED!


The EMU'd Providence Line of our dreams is not going to look a ton different from today. You might kiss 90 MPH for an insignificant number of seconds, but generally speaking the stop spacing doesn't allow for much more than that (thus, not many EMU's on the market ever get rated for speeds >90 because the added expense won't be put to good enough use).

But NE Regionals sustain a maximum-rated 125 MPH from about a mile south of Canton Viaduct all the way to the RI state line. And Acelas sustain 150 MPH (to-be 165 MPH) from the curve by Sharon Station to East Junction in Attleboro. And at those speeds it gets incredibly difficult to time an overtake with any precision, because even a variable station dwell like if the Providence train's staff had to assist a special-needs passenger at Mansfield @ 1-2 min. penalty can be enough that the nonstop Acela has moved too far vs. the next crossover opportunity. Therefore, Amtrak dispatch has to level punitive and unilateral priority on its own trains to keep commuter chaos effects from screwing them up.

^THIS^ is where you need 3-4 tracks, because the speed differential so limits the effectiveness of crossovers for meets, and HSR ops limit how many crossovers you can feasibly spray around like a confetti cannon. Sustained triple-digit speed Amtraks that are at many times running >2x the speed of commuter locals need segregation. And the T needs to trim the fat out of the Providence schedule imposed by Amtrak dispatch priority. Until recently that called for a contiguous 3 tracks everywhere except certain pinch points like Canton Viaduct or the Blackstone River Bridge into RI (both non-issues), and 4-track bulb-outs at most stations. With the recent NEC FUTURE study claiming even higher HSR service levels post-2040, now it looks a lot more prudent to just quad everything up except by the Viaduct and South Attleboro. With slower-speed territory between Forest Hills and 128 just needing it because of sheer nuttiness of traffic levels in the RER era.

But unless we start to see a widening speed differential on other lines (not very likely) or start to see Metro North-level schedule congestion on other lines (also not very likely)...there probably won't be a need likely to arise for any contiguous tri-track segments (just those Worcester tri- passers, which are operationally more akin to rich-man's crossovers).
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Old 05-23-2019, 06:59 AM   #3536
sneijder
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Re: Crazy Transit Pitches

Thank you, F-line. The thoroughness of information you bring to this forum is absolutely incredible.
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Old 05-23-2019, 08:26 AM   #3537
HenryAlan
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Re: Crazy Transit Pitches

Thank you F-Line, that was a hugely informative post. The dispatch complexity are pretty mind boggling.

Quote:
Originally Posted by Tallguy View Post
Again, another polite, useful comment. Is this forum here to take potshots at each other or to discuss transit? I asked a polite question. So far, I've gotten two snide comments.
I don't proport to know everything about everything, and neither should either of you.
And btw, Santa did the secret report, not the Bunny
The point is that unless you have a copy of the Santa study to publish here, we all lack the data to make for a meaningful discussion beyond rough speculation.

Last edited by HenryAlan; 05-23-2019 at 08:41 AM.
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Old 05-23-2019, 06:23 PM   #3538
F-Line to Dudley
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Re: Crazy Transit Pitches

Quote:
Originally Posted by ulrichomega View Post
Surely the bigger cost for Light Rail in that direction is going to be the complete retooling of Sullivan station? You need to make room for an Orange Line platform, at least one Commuter Rail platform (maybe more depending on how we're redoing the Haverhill line's connection here) and a Green Line platform. All of this under a major roadway. It looks like there's physically room to spread out in there, but the supports for the highway surely weren't built with this in mind and will have to be redone.
Complete retooling isn't necessary. The freight tracks side is where Green would go since that's a straight shot from the 3rd Ave. carhouse (with a quick duck-under of the freight wye needed). The highway supports most definitely were built for 2 tracks on that side, since Assembly was a major freight yard until the mid-1980's. That 2-track ROW is 35 ft. wide from Orange Line fence to Clinton Pl. retaining wall, exactly the same measurements as 2 tracks + 2 full-ADA platforms at BU Central station. Only in this case the the tracks would be spread out as close to the wall/fence as the trolley's clearance envelope would go and the 6+6 ft. of platforms would be lumped center into a 12 ft. island.

Since all of that is outside of the Orange station's structure, then it's just a matter of extending the main entrance headhouse serving the 2 current OL islands back over the Green island and shafting down another set of stairs and elevators. If they haven't also plunked a small entrance on Perkins St. by this point, now is the time to finish the job. But that's pretty much it for necessary station construction. It would be a lot more complicated if BRT were chosen for the Ring because space for wider-envelope buses on that side is hard to come by, but this is so easy for LRT that they might even want to do just a Sullivan +1 now and extend C's that normally terminate at North Station to there for some cheap & instant boost. Take those free-throws sooner, figure out the Mystic crossing later.


Now, the CR side is much harder than the freight tracks/UR side because that most definitely was not laid out to support a platform add-on. I honestly have no idea how one fits a pair of 6 ft. wide ADA side platforms or a 12 ft. island in here. Cannibalizing the Orange Line third track for the job isn't feasible because you can clearly see all the big honking girders in the way. And the Orange Viaduct from Community College touches down too close to the Sullivan platforms to try to track-shift the modes around to use that berth.

They say they want it for RER...which means not long from now. It would be great to have if they can do it. But I have no frigging idea how they're going to build it so I hope somebody can show a render of how this is going to work. *SOMEBODY* on the Rail Vision team has to have some inkling of how it would work, otherwise it would be irresponsible to promo Sullivan CR as a coming attraction. I just hope it's a more cunning plan than "build a platform way the hell on Sherman St. behind the Charlestown Garage scrap pile, and walk 2 blocks to the so-called 'cross-platform' transfer"...because that would be a major buzzkill.
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Old 05-24-2019, 07:23 AM   #3539
ulrichomega
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Re: Crazy Transit Pitches

Quote:
Originally Posted by F-Line to Dudley View Post
Complete retooling isn't necessary. The freight tracks side is where Green would go since that's a straight shot from the 3rd Ave. carhouse (with a quick duck-under of the freight wye needed). The highway supports most definitely were built for 2 tracks on that side, since Assembly was a major freight yard until the mid-1980's. That 2-track ROW is 35 ft. wide from Orange Line fence to Clinton Pl. retaining wall, exactly the same measurements as 2 tracks + 2 full-ADA platforms at BU Central station. Only in this case the the tracks would be spread out as close to the wall/fence as the trolley's clearance envelope would go and the 6+6 ft. of platforms would be lumped center into a 12 ft. island.

Since all of that is outside of the Orange station's structure, then it's just a matter of extending the main entrance headhouse serving the 2 current OL islands back over the Green island and shafting down another set of stairs and elevators. If they haven't also plunked a small entrance on Perkins St. by this point, now is the time to finish the job. But that's pretty much it for necessary station construction. It would be a lot more complicated if BRT were chosen for the Ring because space for wider-envelope buses on that side is hard to come by, but this is so easy for LRT that they might even want to do just a Sullivan +1 now and extend C's that normally terminate at North Station to there for some cheap & instant boost. Take those free-throws sooner, figure out the Mystic crossing later.


Now, the CR side is much harder than the freight tracks/UR side because that most definitely was not laid out to support a platform add-on. I honestly have no idea how one fits a pair of 6 ft. wide ADA side platforms or a 12 ft. island in here. Cannibalizing the Orange Line third track for the job isn't feasible because you can clearly see all the big honking girders in the way. And the Orange Viaduct from Community College touches down too close to the Sullivan platforms to try to track-shift the modes around to use that berth.

They say they want it for RER...which means not long from now. It would be great to have if they can do it. But I have no frigging idea how they're going to build it so I hope somebody can show a render of how this is going to work. *SOMEBODY* on the Rail Vision team has to have some inkling of how it would work, otherwise it would be irresponsible to promo Sullivan CR as a coming attraction. I just hope it's a more cunning plan than "build a platform way the hell on Sherman St. behind the Charlestown Garage scrap pile, and walk 2 blocks to the so-called 'cross-platform' transfer"...because that would be a major buzzkill.
Given that's what they did with Ruggles...
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Old 05-26-2019, 05:49 AM   #3540
Tallguy
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Re: Crazy Transit Pitches

Quote:
Originally Posted by ulrichomega View Post
Agreed. This isn't a high priority extension, but it seems like an obvious one after we've nailed a few other Green Line extensions. It won't be the cheapest one that's ever been done, but it's hardly the impossible feat of engineering that something like burying the Grand Junction under Main would be. Personally I'd much rather have an activation of that ROW come from up in Everett as that seems to serve more people assuming urban-ring-as-light-rail happens.

So basically:
  1. 1/Pines Pond
  2. Linden
  3. 99/Maplewood
  4. Cross St
  5. Dana St
  6. Malden Square
  7. Bell Rock
  8. Park L
  9. Santilli Circle
  10. Encore
  11. Sullivan

EDIT: Heck, if you shift the far end of this down to the Showcase and through the traffic circle you can take over the old Rt 1 ROW and send this thing all the way out to Lynn through the swamp. Obviously that's an entirely new order of magnitude of funding and effort for a lot of rail through a place not many people want to go, but if we can't get the Blue Line out there, why not?
My main reason for suggesting routing through Wellington rather than Everett is the timeframe for a Mystic River crossing bridge. Assuming Green Line UR your routing has some advantages.
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