Signal Problems?

[Patrick A.]

What exactly does the MTA mean when they cite "signal problems" as a source of delay on the Subway? As a regular MNR rider I can't ever recall an instance where signal problems held up an MNR train, why does it seem so often (at least once a week) that signal problems are a source of delay.

[Allan]

What exactly does the MTA mean when they cite "signal problems" as a source of delay on the Subway? As a regular MNR rider I can't ever recall an instance where signal problems held up an MNR train, why does it seem so often (at least once a week) that signal problems are a source of delay.

There can be a number of possibilities, such as an interruption of the circuit between a signal and the signal relay room. That would cause all signals within an area (a/k/a block) to go to red and the track level stop arm to go into the up position. That will result in any train within the block to have to stop (and of course all trains behind it) until the prblem can be resolved. Sometimes it will reset on its own, other times signal personnel have to go to the signal, and check all the signals in the area to see where the prioblem started and then correct it. This can take time.

Another possibility is the signals that control the area around a switch track. Since all switches are controlled remotely, the signal tower (or Rail Control Center) has to get the proper indications (on the model board in a signal tower or a screen in the RCC) that the switch track operated properly. If they don't get that then someone has to go to investigate. Until then there will be a restriction of on train movement within the area up to and including holding all trains where they are (hopefully in a station).

[JoshKarpoff]

MN's signal system was upgraded in recent years to a cab signal based system. NYCTA's signal system is the same one they've largely been using since the day the system opened. They're old and they're tired and parts availability isn't what it used to be. The MTA has been working on upgrading the signal system throughout the system, but that takes time. The "A" division (i.e. the numbered lines formerly the IRT) are all currently being upgraded to an electronic system, which is how the "countdown clocks" have been made possible. I believe that the #7 line is in line for signal system upgrades, if they're not already in progress. They aren't however anywhere near done, so in the meantime, until the upgrades are complete, you'll have to live with "signal problems" in your daily commutes.

If you want these projects completed sooner, lobby all of your state representatives in Albany to fully fund the MTA's Capital Program, which is where the funding for major upgrade and construction projects comes from.

[keyboardkat]

How will they run the French TGV high speed train in the subway if they don't get the cab signals done?

[RearOfSignal]

The NYCT Subway has many, many more signals than MNR. More signal more chances to fail.

[tommyboy6181]

Yes- the 7 is getting a new CBTC signalling system (Alstom Urbalis) which is currently being installed. It should be up and running within the next year or two. It's very similar to what was done on the L and they are both interoperable (trains can run mixed mode on it).