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Marta requires 250 metro cars to be operated as six-car trains. The authority plans to issue a request for proposals in December with a deadline for responses of April 2017, and intends to award the contract in November 2017. Delivery of the fleet will begin in 2020 and run through to 2026.
Nevertheless, Marta is willing to consider having trains formed of two triple sets with wide open gangways between cars.
Interesting concept here:
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The Atlanta metro comprises a 77km four-line network which is electrified at 750V dc third rail. However, the new trains will need provision for a pantograph as future extensions to the network may be equipped with overhead electrification.
Currently only MTBA Blue Line has this technology in North America.
I assume that the allowance for two triple sets is if they meet the 8-car capacity of the current max possible consists. If they get 3-car, open-gangway sets, then that could feasibly be achieved.
I am curious if MARTA will require cross-compatability with the QC-312s, since mid-life refurbishing is included in this request. That could allow the paired 3-car trains to tag on a pair of older cars for high-capacity needs.
That pantagraph comment is exciting though~
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However, the Green Line to Bankhead can only accept two-car trains due to the short platforms at Bankhead.
That won't be an issue come the November Referendum.
I hope they go with something that will allow heavy rail and commuter rail to be compatible enough to be combined into the same lines, and use the same cars. (Not the current MARTA cars, but a more comfortable seat interior, for longer trips).
Clayton could be a good first example of how it will work. It could start out from Five Points using third rail tech, just like existing Red and Gold trains. Then at East Point, the train would fork out on a line thru Hapeville/ Forest Park/ Jonesboro, using overhead electrification.
Then Gwinnett could do the same thing for an extension of the Gold Line, into commuter rail. Five Points station just as it is, could be the commuter rail MMPT. Certain trains might would be able to just skip certain ITP stops, for an express service. And all maintenance would be in the same existing MARTA yards.
I hope they go with something that will allow heavy rail and commuter rail to be compatible enough to be combined into the same lines, and use the same cars. (Not the current MARTA cars, but a more comfortable seat interior, for longer trips).
Clayton could be a good first example of how it will work. It could start out from Five Points using third rail tech, just like existing Red and Gold trains. Then at East Point, the train would fork out on a line thru Hapeville/ Forest Park/ Jonesboro, using overhead electrification.
Then Gwinnett could do the same thing for an extension of the Gold Line, into commuter rail. Five Points station just as it is, could be the commuter rail MMPT. Certain trains might would be able to just skip certain ITP stops, for an express service. And all maintenance would be in the same existing MARTA yards.
You'll, quite quickly, run into capacity issues though. Given the scope of commuter rail that the metro really needs, having independent, dedicated routes are really the best bet. That's especially true when you start adding more heavy rail lines into other areas of the metro (like Cobb and Gwinnett).
This is especially true since Kieth Parker has said, in interview, that the plan is to have the Clayton Line built to be compatible with intra-state trains to Macon (and beyond). That means, in all likelihood, that the trains will need to be FRA compliant, which limits the possibility of interacting with the current MARTA system greatly.
What was brought up in the subreddit, though, was the possibility of using these trains along the Clifton Corridor. That certainly seems like much more of a possibility to me.
I hope they go with something that will allow heavy rail and commuter rail to be compatible enough to be combined into the same lines, and use the same cars. (Not the current MARTA cars, but a more comfortable seat interior, for longer trips).
Clayton could be a good first example of how it will work. It could start out from Five Points using third rail tech, just like existing Red and Gold trains. Then at East Point, the train would fork out on a line thru Hapeville/ Forest Park/ Jonesboro, using overhead electrification.
Then Gwinnett could do the same thing for an extension of the Gold Line, into commuter rail. Five Points station just as it is, could be the commuter rail MMPT. Certain trains might would be able to just skip certain ITP stops, for an express service. And all maintenance would be in the same existing MARTA yards.
Safety requirements for FRA, etc. would make those cars ingeritantly heavier and may not be able to use the existing track, but I could always be wrong. There are people a lot more smarter than us making these decisions and they could have thought and researched all this. But you do bring a good reason for the pantogragh request.
My principal takeaway from this is one of irritation. It seems MARTA is dead set on 6-car trains rather than at least retaining the capability to run 8-car trains. In theory, they could run two triplets with one old CQ-312 pair to get 8, but I doubt that will be the case. They could do away with pairs and have some kind of door isolation mechanism for Bankhead trains if they haven't expanded the platform, but I doubt they would do that. I am however pleased to see the consideration of open gangways. Ideally, MARTA would retain an even-numbered scheme, something like A-B()B-A+A-A Where A cars have cabs, B cars are "blind" - are drawbar connections (like the existing pairs but with gangways) + are the standard couplers (like between existing pairs) and () is a gangway connection that is not quite permanent like a drawbar, but not quite as easy as a coupler.
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Interesting concept here:
Currently only MTBA Blue Line has this technology in North America.
This is interesting. The MBTA Blue Line uses 600 volts in their catenary which matches their third rail. MARTA third rail and Atlanta streetcar both use 750 volts. BART uses 1000 volt third rail while Chicago's METRA Electric and South Shore use 1500 volts DC catenary. I can't help but wonder though if MARTA is looking at 25kV AC catenary, but that would complicate the electrical system somewhat. I can't imagine going to overhead catenary and staying at DC. The only advantages are safety as workers would no longer have to be cautious around a high voltage rail at knee-height. However, going to high voltage AC allows a massive reduction in substations and electrical gear as essentially all you need is a transformer and some switch gear, and only every 10 or so miles instead of every mile.
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Originally Posted by primaltech
I hope they go with something that will allow heavy rail and commuter rail to be compatible enough to be combined into the same lines, and use the same cars. (Not the current MARTA cars, but a more comfortable seat interior, for longer trips).
Clayton could be a good first example of how it will work. It could start out from Five Points using third rail tech, just like existing Red and Gold trains. Then at East Point, the train would fork out on a line thru Hapeville/ Forest Park/ Jonesboro, using overhead electrification.
Then Gwinnett could do the same thing for an extension of the Gold Line, into commuter rail. Five Points station just as it is, could be the commuter rail MMPT. Certain trains might would be able to just skip certain ITP stops, for an express service. And all maintenance would be in the same existing MARTA yards.
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Originally Posted by cqholt
Safety requirements for FRA, etc. would make those cars ingeritantly heavier and may not be able to use the existing track, but I could always be wrong. There are people a lot more smarter than us making these decisions and they could have thought and researched all this. But you do bring a good reason for the pantogragh request.
MARTA operating on the national network is absolutely impossible. I have asked this very question of people intimately familiar with railroads and their regulations and there is no practical way for MARTA equipment to operate on the national network. The only possibility would be to convert MARTA into an FRA-regulated railroad which would basically require a complete system and vehicle rebuild to comply with FRA regulations.
This is interesting. The MBTA Blue Line uses 600 volts in their catenary which matches their third rail. MARTA third rail and Atlanta streetcar both use 750 volts. BART uses 1000 volt third rail while Chicago's METRA Electric and South Shore use 1500 volts DC catenary. I can't help but wonder though if MARTA is looking at 25kV AC catenary, but that would complicate the electrical system somewhat. I can't imagine going to overhead catenary and staying at DC. The only advantages are safety as workers would no longer have to be cautious around a high voltage rail at knee-height. However, going to high voltage AC allows a massive reduction in substations and electrical gear as essentially all you need is a transformer and some switch gear, and only every 10 or so miles instead of every mile.
Awesome information Matt! If the concern is cost reduction for implementing service over longer distances, I am a happy camper. The addition of catenary is curious news to say the least
MARTA operating on the national network is absolutely impossible. I have asked this very question of people intimately familiar with railroads and their regulations and there is no practical way for MARTA equipment to operate on the national network. The only possibility would be to convert MARTA into an FRA-regulated railroad which would basically require a complete system and vehicle rebuild to comply with FRA regulations.
Pardon my ignorance on this, because you know so much more about this stuff than I do, but I just want to clarify something.
MARTA's existing cars, yeah, cannot work on FRA-regulated railroad lines. But if they ordered some completely new and different cars from a different maker, that had the capability built in to be powered by a third rail but also the capability to be powered by overhead wires, then would it be absolutely impossible for that new car be made to be legal and compatible with both systems?
Maybe MARTA could do something where, the legacy cars would only ever run on MARTA track and only ever with third rail, but new cars could be designed first and foremost to comply with FRA-regulations for commuter rail usage, but also be made to be compatible with existing MARTA tracks and system.
Again, shoot me down if I'm wrong. Just want to clarify. Because if it's at all possible, then we could really have the best of both worlds here, in my opinion.
No, in that case the problem is reverse, you'd have overly heavy cars running on tracks with the lighter trains. The FTA doesn't regulate things nearly as tightly as the FRA does, but they would not allow it.
As to your latter point, I also don't believe the FRA would allow that either since in theory non-compliant equipment could find itself on the connection to the national network. The only protection would be the human dispatchers and operators knowing not to route/operate the non-compliant trains over the connection. In theory, a computerized dispatching system could prevent this, but it's not an absolute, and manual control will always be an option. The FRA only allows physical connections for non-revenue service tracks like the spur into the east end of the Avondale yard from CSX's ex-Georgia road.
No, in that case the problem is reverse, you'd have overly heavy cars running on tracks with the lighter trains. The FTA doesn't regulate things nearly as tightly as the FRA does, but they would not allow it.
As to your latter point, I also don't believe the FRA would allow that either since in theory non-compliant equipment could find itself on the connection to the national network. The only protection would be the human dispatchers and operators knowing not to route/operate the non-compliant trains over the connection. In theory, a computerized dispatching system could prevent this, but it's not an absolute, and manual control will always be an option. The FRA only allows physical connections for non-revenue service tracks like the spur into the east end of the Avondale yard from CSX's ex-Georgia road.
What do you think the chance of us seeing pantagraph-equipped trains taking up the Clifton Corridor, instead of conventional light rail vehicles?
Or, rather, would you think it's mostly for, like, the longer-distance heavy rail extensions, like Connect 400 and I-20 East?
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