What's the purpose of...

[m7zanr160s]

...the signals in the middle of stations always showing an, at most, yellow aspect no matter what; even if the signal after is green?

[gregorygrice]

...the signals in the middle of stations always showing an, at most, yellow aspect no matter what; even if the signal after is green?

 

It's an approach signal, basically yellow telling them to slow down, but in some cases it is used as a regular signal if things get backed up.

[mark1447]

As Greg says, but also to have the train operator slow down just in case he or she bypasses the required car number board.

[m7zanr160s]

Would it change and stop a train if it were to just blow through a station? I've noticed (J)/(Z)s slow down a little during skip/stop; or subway trains in general when bypassing a platform.

[TrainFanatic]

Would it change and stop a train if it were to just blow through a station? I've noticed (J)/(Z)s slow down a little during skip/stop; or subway trains in general when bypassing a platform.

 

According to the rule book, when bypassing a station, t/o's are to ensure that their train does not leave the station any faster than 15 mph. But ofcourse some t/o's don't allways follow that rule. (I don't mind at all thou, I like flying through a station. )

[Eric B]

These signals (nicknamed "hooligans" when on the ceiling over a right-side platform) are just regular block signals, for when they determined the station needed more block divisions for safety (like when there's a curve, or a switch beyond the station).

 

The yellow is based on the interpretation of the station car marker as the "stop" signal. It's not always consistent, as sometimes the shorter car markers might be before the signal.

Also, if there are no signals within the station, then the last signal entering the station will be yellow. At 121st on the (Manhattan bound), this is actually well before the ststion, and looks awkward, as you then expect a red at the beginning of the station, but the next signal is the on after the station.

And then, you have some places where there is no yellow at all, if the leaving signal is clear. Parkside is an example of this.

 

To make it more consistent, I once tried sending in a suggestion that with LED technology taking hold, they use the older yellow-green to represent those station signals, when it is clear ahead. This would be clearly distinct from the blue-green used for regular "proceed" aspects, yet still be a kind of green indicating the block signals are clear ahead (especially for trains not stopping).

They simply responded that the yellow indicates the possibility of people hanging over the platform, etc. but the green I'm suggesting is yellowish, which would be good to suggest such a lesser element of cautiousness. (The primary purpose of block signals is to indicate the condition of the blocks ahead).

[gregorygrice]

If you want a good example of how these signals work, ride the 42nd St. Shuttle going towards Times Square and look out the front window as you approach the station. The motorman must approach the signal at a certain speed in order for the signals to change. There are like 4 signals in that station.

[Zman]

If you want a good example of how these signals work, ride the 42nd St. Shuttle going towards Times Square and look out the front window as you approach the station. The motorman must approach the signal at a certain speed in order for the signals to change. There are like 4 signals in that station.

 

Those are grade timers and are completely different from your standard yellows in the middle of stations.

 

A yellow automatic signal means, "proceed with caution, prepare to stop at the next signal"; a signal doesn't mean your usual green-yellow-red type. A station car marker (i.e. 10) is a 'miscellaneous fixed signal'. Thus after passing the yellow automatic in the station, the next signal is most likely going to be that 10 (or whatever appropriate station car marker for that length of train).

[CenSin]

According to the rule book, when bypassing a station, t/o's are to ensure that their train does not leave the station any faster than 15 mph. But ofcourse some t/o's don't allways follow that rule. (I don't mind at all thou, I like flying through a station. )

I rode an via the West End earlier this week. It stopped at Bay 50 Street and then skipped Bay Parkway at full speed stopping at 62 Street and 9 Avenue.