Discussion relating to the past and present operations of the NYC Subway, PATH, and Staten Island Railway (SIRT).

Moderator: GirlOnTheTrain

  by R36 Combine Coach
 
Kamen Rider wrote:The systems are not the same, Canarsie is Siemens, Flushing is Thales.
At the Corona Yard tour in June, the superintendent mentioned the CBTC system is being installed on the Flushing Line cars by Canadian firm Telus.
  by FRN9
 
Does anyone know the CBTC systems planned for the Second Avenue Subway and the 2/5 trains?
  by Kamen Rider
 
R36 Combine Coach wrote:
Kamen Rider wrote:The systems are not the same, Canarsie is Siemens, Flushing is Thales.
At the Corona Yard tour in June, the superintendent mentioned the CBTC system is being installed on the Flushing Line cars by Canadian firm Telus.
telus is a phone company...
  by Kamen Rider
 
FRN9 wrote:
Kamen Rider wrote:The systems are not the same, Canarsie is Siemens, Flushing is Thales.
Kamen,

What about power? Is it possible to run the 625V A div trains on 600V B div power? Does anyone know about any hybrid technology that would switch between both voltages?

Thanks,
there is no "switch between voltages" issue because there is no difference. This isn't an AC system. adding or subtracting 25 volts is not as appreciative a difference as, say trying to run on the LIRRs 750 volts, which would fry the resistor grid. at peak power loads, the traction voltage can drop past 600. It's simply a matter getting enough power to turn the wheels.

Voltage is to electricity what pressure is to water. The strength of the push. 600 and 625 are just a baseline standard. the more trains on the circuit, the weaker the push, but that does not automatically mean the trains would stop the moment it gets below 624. Conversely, too much push= fried resistor grid.
  by DaveBarraza
 
The radio systems in particular are not compatible. One of the big selling points of CBTC was *supposed* to inter-operability. The contract specifications for both Canarsie and Flushing require it - but that would require these two large automation companies to divulge certain information that they consider proprietary.

It is up to NYCT as the customer to ensure compatibility of replacement systems that is equal to 100% compatibility the legacy signal systems being replaced have with one another.

It's "Thales" , which is pronounced something sounding like "telus" - so both of you are correct! Thales used be called Alcatel ...when they supplied the SSI interlocking for Bergen Street.
  by Fan Railer
 
DaveBarraza wrote:The radio systems in particular are not compatible. One of the big selling points of CBTC was *supposed* to inter-operability. The contract specifications for both Canarsie and Flushing require it - but that would require these two large automation companies to divulge certain information that they consider proprietary.

It is up to NYCT as the customer to ensure compatibility of replacement systems that is equal to 100% compatibility the legacy signal systems being replaced have with one another.
And this is what the Culver CBTC test track is for.
  by DaveBarraza
 
The Culver test track won't retroactively make the Canarsie and Flushing radios work together.

Thales stated that theirs would be incompatible and MTA said okay.
  by Fan Railer
 
DaveBarraza wrote:The Culver test track won't retroactively make the Canarsie and Flushing radios work together.

Thales stated that theirs would be incompatible and MTA said okay.
I never implied that assumption. The Culver track is for any projects post-Flushing.
  by Jeff Smith
 
Interesting, in-depth, and long article primarily on CBTC; the title is a bit misleading but informative. Some fascinating insights. I appreciate the Atlantic's writing generally speaking; this article certainly seems, unlike so many others in the general media, to be well-informed and researched. It will take more informed minds than mine to speak to some of the details...

The pictures are via the sourced article, although they may be from third-parties; see linked article for attribution: The Atlantic

A brief, fair-use quote really doesn't do the article justice, but here is my attempt <SNIPS>:
Why New York Subway Lines Are Missing Countdown Clocks
...
But here’s the truly crazy thing: The only people who know exactly where that train is are on the train itself. The signal-tower operators don’t know; there’s no one in the Rail Control Center who could tell you, because the F isn’t hooked up to the Rail Control Center. Today, for the F train—along with the G, the A, B, C, D, E, J, M, N, Q, R, and Z—the best the system can say is that the train will get there when it gets there.
...
There is a locked door just below the southwest entrance to the 14th Street A/C/E station. It looks like the door to a small office or break room. But going inside is like stumbling into the Keebler tree. There is a whole world down there: a warren of rooms and equipment, including a working section of track about 20 yards long, that comprise the subway system’s Signal School. This is where the MTA teaches its staff to operate the subway’s switches and signals, which look like simple traffic lights but turn out to be key components of one of the earliest and most complex manmade information-processing systems in existence.
...
The reason there are no realtime countdown clocks on the F line is that even the tower operators don’t know which train is where. All they can see is that a certain section is occupied by a certain anonymous hunk of steel. It’s anonymous because no one has a view of the whole system. A hunk comes into one section of track from somewhere else; the tower’s job is to get it through their section efficiently. The next tower they pass it to will likewise not know whether it’s an F, say, or a G. When there are incidents, trains are located by deduction.
...
By 1994 the MTA was presenting a business case for a new kind of signaling system that had become the standard for modern transit projects: communications-based train control, or CBTC.
...
CBTC does away with the “fixed-block” signaling system, where track is broken into sections that report whether they’re occupied. Instead, each train is equipped with a radio and onboard computer that identifies its precise location, and coordinates that information in real time with a central control center and other trains to decide exactly how fast it can safely go. Trains therefore run with a moving window around them, which constantly shifts depending on their own speed, size, track conditions, and traffic.

The big benefit is that this allows you to run trains closer together. And you can use the track more flexibly. For example, in many fixed-block signaling systems, including New York’s, the signals along certain sections are only set up for trains to go in one direction. But CBTC just sees a bunch of track; it can automatically figure out which parts of it are available, say, for turning trains around.
...
Overall, it's an excellent walk-through of CBTC, previous attempts at it, the ATS that's on the A division which is not compatible, and current plans. I'm sure there's a part of the Capital Plan that is devoted to CBTC.

Accompanying pictures:
You do not have the required permissions to view the files attached to this post.
  by Jeff Smith
 
More on CBTC; as is widely known, the "7" is next: Capital New York
The MTA’s (train) communications problem

In 2017, a second subway line, the No. 7, will switch to communications-based control. Over the next few years, the MTA plans to start installing the system on the tracks beneath Queens Boulevard, the Culver Line/F tracks from Church Avenue to Coney Island, and then the Eighth Avenue line from Columbus Circle to High Street in Brooklyn.
  by Head-end View
 
Someone in a much earlier post asked about whether CBTC will retain the mechanical trip-arms. This subject came up again recently on the MBTA (Boston) forum re: the runaway subway train earlier this week.

I for one, would hate to see the trip-arms abolished as being considered obsolete in the new era of electronic, computerized train control. The trip-arms may be a hundred year old technology, but they are a simple, time-proven, reliable safety device. In the Williamsburg Bridge rear-end train collision some years ago the tripping of the train's brakes reduced the impact speed considerably lessening the impact.

And as the Washington Metro's sad accident experience has proven, this electronic stuff can malfunction causing accidents that they're supposed to prevent. Electronics are no substitute for mechanical trippers.
  by jonnhrr
 
I understand what you are saying and I agree that sometimes the simpler proven approach is better, but there is no way you can keep trip arms and have a moving block system, except keeping then at the interlockings, which will be fixed.

Jon
  by Head-end View
 
Then what would you suggest in the way of an electronic safeguard that would be as equally reliable as the trip arms?
  by MattW
 
I now for fact that BART, WMATA and MARTA do not use trip-arms. WMATA's issues aside, the other two systems are quite reliable. Now I know MARTA doesn't use CBTC, and I'm pretty sure WMATA's doesn't count as CBTC and neither would BART's system, but they do work pretty well without that mechanical backup. Whether the simpler electronic fail-safe could be used on NYC's system, I don't know.
  by DaveBarraza
 
MattW wrote:I now for fact that BART, WMATA and MARTA do not use trip-arms. WMATA's issues aside, the other two systems are quite reliable. Now I know MARTA doesn't use CBTC, and I'm pretty sure WMATA's doesn't count as CBTC and neither would BART's system, but they do work pretty well without that mechanical backup. Whether the simpler electronic fail-safe could be used on NYC's system, I don't know.
Except that (factually speaking) MARTA actually does use train stops. Their quick reaction times cannot be bested by any communications based system.

http://www.railfanguides.us/ga/marta/" onclick="window.open(this.href);return false;

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