MBTA "Transformation" (Green Line, Red Line, & Orange Line Transformation Projects)

FormFollowsBudget said:
I have to guess the MBTA is making the canopy a requirement alongside the ramp to prevent primarily snow/ice from accumulating on the ramp, rather than relying on the reliability of maintenance and snow-clearing contracts to ensure the ramp remains clear and accessible at all times.. but the project probably doesn't have the budget for a nicer canopy than this off-the-shelf looking one..

Dealt with enough MBTA design comments to venture a guess at it...
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It looks like it covers less than half the ramp. So if keeping it clear is the goal, it's not going to meet it, in addition to being an eyesore.
 
JeffDowntown said:
Other than the Riverside Line, I am not sure how much benefit there is on rated speed increases on the Green Line. Speed on much of the line is controlled by stop spacing and other safety factors like curves, slopes (tunnel to North Station, for example).

Also, are you sure you want this before GLTPS is fully implemented?
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Yeah, with the NTSB breathing down their necks there isn't a chance in hell that Green sees any speed limit increases until GLTPS Phase 2 is completely in-place. Even Phase 1's warning-only protection doesn't completely remove operator error from the equation. So unfortunately the D isn't going to be doing 50 again until the technology fully closes the loophole on missed signal sightlines (the presumed cause of the fatal 2008 rear-end crash). And active switches are going to continue to be restricted to 10 MPH because an ignored Phase 1 warning buzzer leaves the loophole still open on whoopsies like the GLX split-switch derailment of 2 years ago.

Lechmere Viaduct might well be a Type 8-paranoia thing, which puts it on the same timeline as GLTPS Phase 2 all the same.
 
F-Line to Dudley said:
Lechmere Viaduct might well be a Type 8-paranoia thing, which puts it on the same timeline as GLTPS Phase 2 all the same.
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The Bredas do feel a bit unstable even at moderate speeds - more hunting motion than is comfortable IMO on the Riverside Branch.
 
BronsonShore said:
It looks like it covers less than half the ramp. So if keeping it clear is the goal, it's not going to meet it, in addition to being an eyesore.
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Not saying you're wrong, just venturing to guess someone at the MBTA thinks it's a good idea and this is what we get now.
 
Stlin said:
Honestly, I think it'll top out at 50. Worth remembering these speed increases are less "increase speeds from baseline" and more "restoring design speeds." I believe that large parts of OL were designed to operate at 55, while the RL extension was originally designed to operate at 50, and no higher. Increasing above 50 would probably take quite a bit more design and validation work that probably isn't in scope.
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Rather too bad, always think sections like that that have decent stretches along the highway are the perfect advertisement for the T - blast through at 60+ mph with cars stuck under 50 (or much, much worse in the case of 93).
 
F-Line to Dudley said:
So unfortunately the D isn't going to be doing 50 again until the technology fully closes the loophole on missed signal sightlines (the presumed cause of the fatal 2008 rear-end crash). And active switches are going to continue to be restricted to 10 MPH because an ignored Phase 1 warning buzzer leaves the loophole still open on whoopsies like the GLX split-switch derailment of 2 years ago.
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Are the Type 10s capable of going 50 mph? I recall reading that the Type 10s are designed for only 43 mph, which is very disappointing if true.
 
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themissinglink said:
Are the Type 10s capable of going 50 mph? I recall reading that the Type 10s are designed for only 43 mph, which is very disappointing if true.
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CAF Urbos 3's are designed for 43-50 MPH depending on particular lengths, so the Type 10's probably have an identical design speed as the propulsion systems would be identical.

Most of the schedule and speed improvements for the Type 10's are not going to come from the topline radar reading, but from the shorter dwell times from all-door low-floor boarding and GLTPS Phase 2 whacking the 10 MPH-over-switches speed restrictions, eliminating sightline caution pauses, and easing curve restrictions.
 
bakgwailo said:
Rather too bad, always think sections like that that have decent stretches along the highway are the perfect advertisement for the T - blast through at 60+ mph with cars stuck under 50 (or much, much worse in the case of 93).
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Safe and comfortable train top speed is an optimization of the wheels' conical profile to handle curve radii. The more conical the better it handle curves without squealing and wearing down the flange but the lower the speed it develops hunting oscilation. The Red Line has sharper curves at Harvard, under Fort Point, and by Fields Corner than anything on the Orange Line so the specified wheel profile probably doesnt lend itself to higher speeds comfortably
 
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