• Green Line Derailments Increasing

  • 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

  by BandA
 
You could have the normal Type 9s, then an optional order where the cab end comes off and is replaced with an articulating joint where 1/2 of a Breda is attached. So you would have a double-length car with three articulating joints. Would be fun to service.
  by BostonUrbEx
 
F-line to Dudley via Park wrote:
Disney Guy wrote:"Eliminate the Park St. loop and install universal crossovers south of the station"
Would be confusing to passengers unless the boarding location, including any on the "inbound" side, for each destination was the same for all hours and all days and all trips. Also an operational nightmare if you have occasional "wrong way" pull ins and pull outs for cars terminating at Park St. (tracks 2 and 3) mixed with through service.
Actually, he's referring to a $12M fed grant award the T got about 7 years ago to install crossovers from the inbound loop side to the outbound track to facilitate thru service on the inner track. ...
No, he read me correctly. While the project you outlined is also a key component to Green Line improvements, I was indeed talking about eliminating the loop entirely in favor of universal crossovers west (south) of Park in addition to the project you outlined. I'm not sure how common Park St short turns are lately, especially if both eastbound tracks were to be capable of continuing to Lechmere, so I figure crossover might be feasible over a loop.
  by F-line to Dudley via Park
 
BostonUrbEx wrote:
F-line to Dudley via Park wrote:
Disney Guy wrote:"Eliminate the Park St. loop and install universal crossovers south of the station"
Would be confusing to passengers unless the boarding location, including any on the "inbound" side, for each destination was the same for all hours and all days and all trips. Also an operational nightmare if you have occasional "wrong way" pull ins and pull outs for cars terminating at Park St. (tracks 2 and 3) mixed with through service.
Actually, he's referring to a $12M fed grant award the T got about 7 years ago to install crossovers from the inbound loop side to the outbound track to facilitate thru service on the inner track. ...
No, he read me correctly. While the project you outlined is also a key component to Green Line improvements, I was indeed talking about eliminating the loop entirely in favor of universal crossovers west (south) of Park in addition to the project you outlined. I'm not sure how common Park St short turns are lately, especially if both eastbound tracks were to be capable of continuing to Lechmere, so I figure crossover might be feasible over a loop.
Behind-schedule B's get shorted all the time at Park...more than ever. Though that would not be so prevalent if real branch signal priority fixed the garbage-in/garbage-out situation at the portals. But curve radius is not the be-all/end-all for why we can't have full off-shelf trolleys in Boston. There's height pinches in a couple places like the C/D portal tunnel under the Beacon St. substation that are blockers and PITA to try to solve with tunnel shaving. Things like that force a very odd and top-heavy weight distribution that going lower-floor would exacerbate. The 7's already sway like hell at high speed.

So getting rid of one single loop does nothing to widen the purchase options unless all other design-kludge forcing constraints were solved...all of them. There's no single, simplistic killshot. And since some of those height pinches were already shaved for the LRV era they have limited options for going to the well. Not impossible, but well into diminishing returns where each solve takes escalating $$$ with the killshot still an elusive thing.
  by CRail
 
All Comm. Ave. service turns at Park Street unless diverted.
Bramdeisroberts wrote:I was responding to someone's suggestion that they do a similar conversion to the 8's and 9's, though I'm honestly shocked (not really) that the T never considered a similar upgrade to the 7's
I believe they did, but it was decided to go with new cars. They were probably deterred by the capital cost of converting the carhouses to be compatible with new car lengths. I'd much rather see a 100% fleet of Super 7s.
  by F-line to Dudley via Park
 
CRail wrote:All Comm. Ave. service turns at Park Street unless diverted.
Bramdeisroberts wrote:I was responding to someone's suggestion that they do a similar conversion to the 8's and 9's, though I'm honestly shocked (not really) that the T never considered a similar upgrade to the 7's
I believe they did, but it was decided to go with new cars. They were probably deterred by the capital cost of converting the carhouses to be compatible with new car lengths. I'd much rather see a 100% fleet of Super 7s.
Kinki did indeed gave the T a detailed presentation (though don't think the renders were ever released online) several years ago before the midlife rebuild program was RFP'd about modding the 7's during overhaul with a new low-floor "sandwich section" between the two existing ends that would work for all Green Line curve and clearance specs. Feasibility and per-car price point checked out fine for the Kinki-manufactured sandwich section, but the carhouses just couldn't handle it without blowout-cost retrofits and a daunting timeframe for blitzing the mods without pinching day-to-day maint capacity. Not just re-equipping the service bays, but very invasive building renovations and possible outright no-go with Lake St. carhouse for the increased length. If GLX were about 8 years earlier on the schedule they might've had a chance by starting out with Brickbottom heavy-repair facility being built from Day 1 able to handle it. That would give them more time, less above-and-beyond budget pressure for OT labor, and less ops disruption for a Riverside renovation, and ability to punt the tougher mods at Reservoir and Lake St. further out on a different CIP budgeting period by segregating the 8's exclusively to the B and C while they reloaded the facilities budget. But the construction schedule for Brickbottom didn't project anywhere close to a match 8 years ago when they were evaluating the Kinki proposal, let alone match umpteen GLX delays later. The proposal was very attractive on the merits because Kinki was offering a pretty solid feasibility guarantee, but there wasn't any timeframe matchup that could make it work at any practical level for the support facilities.
  by MBTA3247
 
That's not on the B Line, that's the shop lead at Reservoir.
  by jwhite07
 
Looks to me from the picture that it was a Type 7 that derailed. Can't quite tell if it made contact with that Type 8 on the adjacent track.
  by Type 7 3684
 
Looks like it was 3659 that derailed. Out of service for repairs according to NETransit.
  by F-line to Dudley via Park
 
The Chestnut Hill Ave. trackage is in garbage condition and in much need of some upkeep dough. I'm surprised this doesn't happen more often given how much it's used every single day during shift changes.
  by CRail
 
How is it in "garbage condition?" Have you ever ridden over it?
  by BostonUrbEx
 
CRail wrote:Have you ever ridden over it?
Can this be arranged? :-D
  by F-line to Dudley via Park
 
CRail wrote:How is it in "garbage condition?" Have you ever ridden over it?
Yes, actually. Ridden it 2 or 3 times in revenue service when the Cleveland Circle train I was on was waived on to BC in advance of the early-PM shift change. I haven't done it in a few years, but used to be an inspector's discretion decision whether to let passengers stay on board so it occasionally paid to find an excuse to ride the C after lunch in hopes of getting some rare mileage.


As for "garbage condition"...look at the curve rail on both ends of the street, and all of the frogs. Chestnut Hill Ave. hasn't been resurfaced in over 20 years, and all of the original pavement has crumbled away around the rail replaced only by overlapping layers of pothole patch that have to be refilled each year. The rail moves so much because of shot substrate that old patch breaks loose all the time. Those new green-painted bike lanes the city put in a few years ago are already a safety hazard of deep gashes around the tracks, and a big bone of contention for bicyclists in the neighborhood. The straightaway between Beacon and Comm Ave. has held up well, but both intersections are in deplorable shape and way overdue for track + surface replacement. Lack of any effective MBTA + BTD coordination has back-burnered any basic fixes far, far longer than would be allowed anywhere else in the city, but it's now deteriorating to the point where another year of pothole patch isn't going to cut it.

To be completely fair to the T here, they probably would've been more inclined to repair before it got this bad if BTD weren't so notoriously dysfunctional and prone to neighborhood-on-neighborhood factionalism. There's a reason why that nice paving job Brookline did on Beacon St. turns into a boulder field at the city line, and it has more to do with the torturous politics of Cleveland Circle and Cleveland Circle redevelopment than anything else.
  by jwhite07
 
The MBTA needs to do what Toronto does with its in-street trackage - use coated steel ties and encase the whole thing within a deep concrete trench. No ballast/wood under asphalt. That way the structure is solid and nothing moves except the asphalt abutting it. Build it to be durable and last many years... but with the T's dim view of street running that ain't happening.

Having said that, CRail is correct that nobody here knows that track conditions caused the derailment. The leading car, a derailment-susceptible Type 8 no less, made it past the point of derailment. So was it really a "garbage condition" track issue? Maybe a switch point got picked by a thin wheel flange? Or an increase to an improper and unsafe operating speed? Not ours to know - I'm sure it's been investigated thoroughly by those who are responsible. But even if every one of us took a ride over that trackage (I have a few times, though this was many years ago), it wouldn't tell us anything, unless you happen to be a closet professional track engineer and you've brought all of the proper geometry measuring tools with you in your back pocket. Good rare mileage though.