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  • Discussion relating to commuter rail, light rail, and subway operations of the MBTA.
Discussion relating to commuter rail, light rail, and subway operations of the MBTA.

Moderators: sery2831, CRail

 #1377855  by eustis22
 
>the plan would have involved elimination of Commuter Rail service between BON and Reading with the Orange Line in its place, service to Lawrence and Haverhill would run via the Lowell Line and the Wildcat branch through Wilmington.

From your keyboard to God's monitor....
 #1395476  by cloudship
 
I remember reading somewhere that the Washington St tunnel was initially designed to handle regular rail cars at the beginning, although I can't seem to find this now. This had me wondering - could something like the MTA's M7 cars work on the orange line, or would they be too large to fit?
 #1395480  by CS
 
Not sure where you read that, but it's incorrect for many reasons including the most important - the tunnels cannot even fit Red Line cars.
 #1395492  by MBTA3247
 
The only subway line in the world I know of that was designed for regular railroad equipment is part of the Circle Line in London, which was built with Great Western backing and originally used 7' gauge.
 #1395522  by ExCon90
 
That continued for quite a few years, even after conversion to standard gauge. I have a London Transport Underground timetable from 1939 showing some through rush-hour service over the Great Western from Windsor & Eton Central and Slough to either Kings Cross or Liverpool St. on the Metropolitan via Paddington; there was no time for an engine change at Paddington, so it must have been steam throughout. The service ended with the outbreak of war in 1939 and was never resumed.
 #1395609  by F-line to Dudley via Park
 
Orange's 1909 tunnel can't even take Red Line-sized cars. It was the last subway built in these parts before BTC and BERy planners had gained enough experience to settle on a default tunnel dimension for construction consistency's sake. Pretty much everything built after the Red Line in 1912 is buffed out to Red's loading gauge. Including the Green Line Boylston St. subway, Kenmore Station and portals, Huntington subway, 1963 GC-Haymarket partial replacement under City Hall Plaza, and '95-04 North Station Under relocation. Ditto Orange's 1967 South Cove tunnel and 1975 North Station tunnel + portal, and the Silver Line Transitway (which is even wider in spots, particularly around curves). The turn radius in these post-1912 tunnels may not all clear Red rolling stock and one-off pinch points (e.g. the low roof on the C/D portal tunnel underneath the old Boston Edison substation on Beacon St.) can be specific to each line...so it's not like everything is intended to be out-of-box capable of being converted to run the 01800's. But for 100 years now it's been default practice to Keep It Simple Stupid™ by designing and engineering to one default loading gauge guaranteed to fit anything. It's much easier to work from generous defaults rather than designing everything custom to fit snugly around a particular line's unique rolling stock. You'd have situations where--oops!--somebody brain-farted on the metric-to-English units conversion and a whole section of new Green Line wall has to be torn out and redone because it fouls an LRV's clearance envelope.


RR tunnels are a different ball of wax because you have other 50-year future-proofing variables to consider during design like potentially needed high-and-wide freight clearances, future 25 kV overhead electrification clearances, and/or future 25 kV electrification clearances over high-and-wide freight clearances to factor in. With that hedge on freight future-proofing varying significantly line-by-line, and a catch-all default max (23 ft. super-tall vertical clearances for 25 kV electrification over double-stack freight cars) simply not feasible for every single construction situation.
 #1408336  by Arlington
 
Orange line is dispatching trains more-reliably at Oak Grove using an extra operator who boards as soon as an arriving northbound train has shut down and starts preparing for southbound departure while the arrival trip's operator walks the length of the train doing the inspection.

This article:
http://www.dotnews.com/2016/mbta-eyes-s ... range-line" onclick="window.open(this.href);return false;

says that so far it has been used to improve dispatch reliability at Oak Grove, but if also implemented at Forest Hills it could boost capacity by 10%
 #1408355  by Arborwayfan
 
The Santiago Metro (Chile) does this at busy terminal and short-turn stations. Since their trains generally arrive at an off-only platform, head into the tail tracks in the tunnel beyond the station, then revers and cross over to the departure track, you get to see the odd sight of the train pulling away from the platform with the next operator already in the rear cab setting it up to take over and drive it back up to the departure platform. It seems to work really well, and I'm glad to see the T doing it, too.
 #1408410  by dbperry
 
Arlington wrote:Orange line is dispatching trains more-reliably at Oak Grove using an extra operator who boards as soon as an arriving northbound train has shut down and starts preparing for southbound departure while the arrival trip's operator walks the length of the train doing the inspection.
This "drop back" procedure was discussed at the 11/7 FMCB meeting. Presentation mentioning "drop back," along with information on new cars and all things Orange, is here:

http://www.mbta.com/uploadedfiles/About ... 7%2016.pdf" onclick="window.open(this.href);return false;
 #1408689  by BandA
 
That's a good presentation. Speeding the turnaround by 30 sec at the terminals sounds awesome. Things that strike my are that the trains only run at 18MPH?? Need an express track and skip-stations. And new trains 3-6 years from now will go from 6 min headway to 4 min. Why can't headway be even shorter? Run 'em 2 minute headway - strap giant pillows to the end of trains and allow them to bounce harmlessly off of each other in case of collision in station. Kidding/not kidding.
 #1426996  by rhodiecub2
 
One more question regarding the 3rd track from Community College to Wellington. If they ever did set this up for use of an express track, which track would be used for the express track in the am rush hour and the pm rush hour?
 #1427025  by deathtopumpkins
 
rhodiecub2 wrote:One more question regarding the 3rd track from Community College to Wellington. If they ever did set this up for use of an express track, which track would be used for the express track in the am rush hour and the pm rush hour?
I believe he initial plan wasn't for a specific track to be the express track, but rather to have the flexibility to run either an express or a local train on either track. That's why all stations had platforms for all 3 tracks.

Nowadays, if the T planned on actually running express trains (which would be pointless, as I've explained previously. You could skip Community College and maybe Assembly, but the state and developers would balk at trains skipping the brand new, expensive station. If you're only skipping one or two stations, there's no real point. You'd save people maybe a minute or two of travel time. The triple-tracking was a legacy of the original plan to go out to Reading, which would have made express trains more necessary.), if they wanted to use separate tracks for express/local trains, they'd have to use the easternmost track for express trains in the PM peak (no usable platform at Assembly or Community College), and the middle track for locals. In the AM peak, same thing, easternmost track for expresses, which would be a nightmare to dispatch.

So in short, it ain't gonna happen.
 #1427041  by MBTA3247
 
Normal practice on triple track subway lines is to use the center track for express trains, with inbound expresses in the morning and outbound expresses in the evening. This avoids the need either for expresses to cross over the opposing track during one rush hour period or the other, or for trains running in a given direction to use different tracks at different times of the day.

As the Orange Line exists today, expresses are never going to happen. If the T ever does decide to extend the line out to Reading, they'll undoubtedly rehab the second platform at Community College, build a second island platform at Assembly Square, and possibly modify the stations at Malden and Oak Grove with dual island platforms, allowing express trains to run from Oak Grove all the way to Community College.
 #1427047  by RenegadeMonster
 
What do they use the Eastern most track for now?

Occasionally in the morning when commuting in on the Newburyport / Rockport line I see a Orange line train on it.

Sometimes it's just a two car set, which I assume is not a revenue train. But sometimes its a 6 car set or stopped at Sullivan Square.
 #1427058  by CRail
 
It's a test track. 0704/0705 ran on it quite a bit when they were delivered.

Malden center would not need reconfiguration. The Commuter Rail track would be the northbound.
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