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Union Tpke

Why Your Subway Train Might Start Moving Faster

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18 minutes ago, Union Tpke said:

@RR503 The program measures runtimes between departures and arrivals, so you cannot easily show delays from merges, as these would be in the form of increased dwell times. The awful switch layout at Jamaica Center really delays (E) service. To show this I showed the running time from one station further west, Jamaica-Van Wyck. The comparison between Southbound and Northbound (E) should show the impact of the lousy switching layout:

 

 


       

RuntimeSouthbound_Train_-3RuntimeNorthbound_Train_-3

 

I think this is more about the terminal capacity issue. It is normal to see northbound J and E waiting at Sutphin Blvd to enter Jamaica Center. To me, the southbound E is very slow between Jamaica Van Wyck and Union Tpke. 

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6 minutes ago, whz1995 said:

I think this is more about the terminal capacity issue. It is normal to see northbound J and E waiting at Sutphin Blvd to enter Jamaica Center. To me, the southbound E is very slow between Jamaica Van Wyck and Union Tpke. 

Saying terminal layout/operation is bad and saying that terminal capacity is low is the same thing. 

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12 minutes ago, RR503 said:

Saying terminal layout/operation is bad and saying that terminal capacity is low is the same thing. 

And there is one more question. Does the northbound chart include the dwell time at Jamaica Center? If yes, two minutes dwell time at terminal is reasonable.

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37 minutes ago, whz1995 said:

And there is one more question. Does the northbound chart include the dwell time at Jamaica Center? If yes, two minutes dwell time at terminal is reasonable.

No, it should start when the train starts.

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16 hours ago, RR503 said:

No, it should start when the train starts.

With me living at 179 street GTFS/Beacon/ITRAC vs dispatcher bell has some fraud going on. Bell rings, sometimes trains leave 45 sec to 2 mins before GTFS scheduled departure with 1-2 mins left on the clock. Sometimes the SB F is held with hold lights at 75th avenue or Union since it got to the merge "too fast". Travel time from Origin to 2nd station would be very unstable since trains leave earlier than scheduled for OTP.

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2 minutes ago, bulk88 said:

With me living at 179 street GTFS/Beacon/ITRAC vs dispatcher bell has some fraud going on. Bell rings, sometimes trains leave 45 sec to 2 mins before GTFS scheduled departure with 1-2 mins left on the clock. Sometimes the SB F is held with hold lights at 75th avenue or Union since it got to the merge "too fast". Travel time from Origin to 2nd station would be very unstable since trains leave earlier than scheduled for OTP.

I take the (F) from Kew Gardens to get to school, and it almost always has to wait for a minute or more at 75th Avenue, waiting for an (E). I had presumed that the issue was awful dispatching at 179th and/or JC. So they let trains leave early? That is idiotic.

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9 hours ago, bulk88 said:

With me living at 179 street GTFS/Beacon/ITRAC vs dispatcher bell has some fraud going on. Bell rings, sometimes trains leave 45 sec to 2 mins before GTFS scheduled departure with 1-2 mins left on the clock. Sometimes the SB F is held with hold lights at 75th avenue or Union since it got to the merge "too fast". Travel time from Origin to 2nd station would be very unstable since trains leave earlier than scheduled for OTP.

There isn't necessarily any fraud for the discrepancy. Typically, tracking software is set to read occupying the first track circuit outside of the terminal for timekeeping, since the train is already in the station there is no way to record when it leaves until it hits another recorded location. For example LIRR trains record when they pass the signals into the tunnel when they depart Penn because there's no way to record when the wheels started turning.

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On 5/20/2019 at 3:11 PM, bulk88 said:

With me living at 179 street GTFS/Beacon/ITRAC vs dispatcher bell has some fraud going on. Bell rings, sometimes trains leave 45 sec to 2 mins before GTFS scheduled departure with 1-2 mins left on the clock. Sometimes the SB F is held with hold lights at 75th avenue or Union since it got to the merge "too fast". Travel time from Origin to 2nd station would be very unstable since trains leave earlier than scheduled for OTP.

19 hours ago, Jsunflyguy said:

There isn't necessarily any fraud for the discrepancy. Typically, tracking software is set to read occupying the first track circuit outside of the terminal for timekeeping, since the train is already in the station there is no way to record when it leaves until it hits another recorded location. For example LIRR trains record when they pass the signals into the tunnel when they depart Penn because there's no way to record when the wheels started turning.

GTFS (schedules) and GTFS-RT (real-time train positions) are two different things. Late starts are absolutely an issue, but those show up on the RT feed clear as day -- though I will admit that RT tracking at/around terminals can be spotty. 

FWIW, it's possible that the clocks are off. Absent terminal congestion, it's rare for terminal dispatchers to push intervals out early. 

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12 minutes ago, RR503 said:

GTFS (schedules) and GTFS-RT (real-time train positions) are two different things. Late starts are absolutely an issue, but those show up on the RT feed clear as day -- though I will admit that RT tracking at/around terminals can be spotty. 

FWIW, it's possible that the clocks are off. Absent terminal congestion, it's rare for terminal dispatchers to push intervals out early. 

What do you think the issue is at 179th?

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35 minutes ago, RR503 said:

GTFS (schedules) and GTFS-RT (real-time train positions) are two different things. Late starts are absolutely an issue, but those show up on the RT feed clear as day -- though I will admit that RT tracking at/around terminals can be spotty. 

FWIW, it's possible that the clocks are off. Absent terminal congestion, it's rare for terminal dispatchers to push intervals out early. 

I don't disagree, I merely state that such discrepancies in the 90 second window aren't dispositive. 

I was a regular rider from 2012-2015 so there are plenty of cases of trains being pushed out in that time frame.

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Posted (edited)
2 minutes ago, Jsunflyguy said:

I don't disagree, I merely state that such discrepancies in the 90 second window aren't dispositive. 

I was a regular rider from 2012-2015 so there are plenty of cases of trains being pushed out in that time frame.

Oh, I wasn't disagreeing with you. Merely wished to offer more clarity to bulk88s question. 

Edited by RR503

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Just think, no changes to the physical characteristics of the Railroad, just been wasting all that time these years.

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11 hours ago, Union Tpke said:

(R) Between 59th St and Bay Ridge Av Brooklyn NB 25 40 Y 

(N)/ (D) Leaving Atlantic Av-Barclays Center Brooklyn NB 10 20 Y 10

(N) Between 86th St and Stillwell Av Brooklyn NB 20 Limit Removed Y

The typical crawl spots. Let's see if I actually start noticing any changes.

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7 minutes ago, Bay Ridge Express said:

(R) Between 59th St and Bay Ridge Av Brooklyn NB 25 40 Y 

(N)/ (D) Leaving Atlantic Av-Barclays Center Brooklyn NB 10 20 Y 10

(N) Between 86th St and Stillwell Av Brooklyn NB 20 Limit Removed Y

The typical crawl spots. Let's see if I actually start noticing any changes.

Keep in mind speed limits can be removed because the maximum attainable speed does not exceed the maximum safe speed. A little slight of hand to keep an eye out for.

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So it looks like the 11th St Cut Queens bound track, as well as the n/b local track at Queens Plaza, had the timers tweaked or a change in dispatcher. 

The 11th St Cut timers now clear at the posted speed. 

At Queens Plaza, the wheel detectors (!) were active for the first time that I've seen while an (M) crossed over as my (R) was pulling in. And no the (R) didnt diverge. 

Normally the (R) is held outside the station if an (M) gets the lineup to switch to the local. 

More suprising was that the wheel detectors cleared at the posted speed as well and didnt delay the (R)

This was about 10 minutes ago, smoothest ops I've witnessed there in a while. 

@RR503 any input?

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3 hours ago, RestrictOnTheHanger said:

So it looks like the 11th St Cut Queens bound track, as well as the n/b local track at Queens Plaza, had the timers tweaked or a change in dispatcher. 

The 11th St Cut timers now clear at the posted speed. 

At Queens Plaza, the wheel detectors (!) were active for the first time that I've seen while an (M) crossed over as my (R) was pulling in. And no the (R) didnt diverge. 

Normally the (R) is held outside the station if an (M) gets the lineup to switch to the local. 

More suprising was that the wheel detectors cleared at the posted speed as well and didnt delay the (R)

This was about 10 minutes ago, smoothest ops I've witnessed there in a while. 

@RR503 any input?

Good to hear the timers are actually being recalibrated. 

As for the WDs, trains can berth fully at QP on WD even if they don't have a lineup out. See, for example, this video:

 

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27 minutes ago, RR503 said:

As for the WDs, trains can berth fully at QP on WD even if they don't have a lineup out. See, for example, this video:

Looks like dispatching makes a world of difference, good decision to use WDs instead of a hold outside the station. 

On another note I thought WDs were on their way out

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8 minutes ago, RestrictOnTheHanger said:

Looks like dispatching makes a world of difference, good decision to use WDs instead of a hold outside the station. 

On another note I thought WDs were on their way out

I'm confused as to why the WDs were triggered. AFAIK, they cannot be used a la carte; they are just active when their protected switch (here, switch 463, the one leading to the express track) is reversed. It would seem that something before your (R) used that switch and it was not lined back until after your (R) entered. @Jsunflyguy is this correct?

WDs are generally not installed in new interlockings, and it seems they're being phased out in favor of DGTs (which is what has replaced their functionality at newer rebuilds). 

Edited by RR503
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13 minutes ago, RR503 said:

I'm confused as to why the WDs were triggered. AFAIK, they cannot be used a la carte; they are just active when their protected switch (here, switch 463, the one leading to the express track) is reversed. It would seem that something before your (R) used that switch and it was not lined back until after your (R) entered. @Jsunflyguy is this correct?

WDs are generally not installed in new interlockings, and it seems they're being phased out in favor of DGTs (which is what has replaced their functionality at newer rebuilds). 

An (M) was crossing through the switch. I was trying to emphasize that letting the (R) enter the station as it crossed instead of holding in the cut should be the norm instead of the exception. 

Sorry if I was unclear, and thanks for the insight. Always appreciated 

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7 minutes ago, RestrictOnTheHanger said:

An (M) was crossing through the switch. I was trying to emphasize that letting the (R) enter the station as it crossed instead of holding in the cut should be the norm instead of the exception. 

Sorry if I was unclear, and thanks for the insight. Always appreciated 

No no, no lack of clarity on your part. I'm confused as to why the WDs were active. See this screenshot:

eqFr9p0.png

WDs only active when that switch (the local-express switch, or the mirror of the one the (M) uses) is reversed, or lined to cross locals to the express. I'm just wondering why it was active for your (R). But yes, I agree (R)s should be allowed to come in on WD at all times. 

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4 hours ago, RR503 said:

I'm confused as to why the WDs were triggered. AFAIK, they cannot be used a la carte; they are just active when their protected switch (here, switch 463, the one leading to the express track) is reversed. It would seem that something before your (R) used that switch and it was not lined back until after your (R) entered. @Jsunflyguy is this correct?

WDs are generally not installed in new interlockings, and it seems they're being phased out in favor of DGTs (which is what has replaced their functionality at newer rebuilds). 


It is possible to select 'short' routes on most Modern NX panels or Video Display Interlockings. It's my understanding that Queens Plaza has both,  Newer electronic interlockings will automatically select the reduced overlap (and thus forcing the timer/WD). But no, there is no button that says 'run WD', however the system that controls the WDs is in the controlling Tower in a separate unit. It can be bypassed if the system is not performing to spec. Based on a general observation of several signal systems, I suspect that the WDs have been in bypass, as such the route with the short control line was prohibited from use. Now that they're going through and recalibrating all the timers on the Broadway Lines I guess QP finally got theirs fixed. Now that it is cut back in this route is now permitted again.

Side note: they published the increased speeds but word on the street is not all the timers have been upgraded, so the defacto speed limit remains in some places. 🤔

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6 hours ago, Jsunflyguy said:

It is possible to select 'short' routes on most Modern NX panels or Video Display Interlockings. It's my understanding that Queens Plaza has both,  Newer electronic interlockings will automatically select the reduced overlap (and thus forcing the timer/WD). But no, there is no button that says 'run WD', however the system that controls the WDs is in the controlling Tower in a separate unit. It can be bypassed if the system is not performing to spec. Based on a general observation of several signal systems, I suspect that the WDs have been in bypass, as such the route with the short control line was prohibited from use. Now that they're going through and recalibrating all the timers on the Broadway Lines I guess QP finally got theirs fixed. Now that it is cut back in this route is now permitted again.

Yeah, they’ve been bypassing a lot of WDs lately. Brooklyn Bridge lost theirs too. Where I get confused with Queens Plaza is with the sheer variety in time control. Depending on a situation, a short — or at least partially occupied — route seems to variously use 2 shot GT or WD to get trains up to a red home signal. Can’t say I completely follow how what triggers each...

6 hours ago, Jsunflyguy said:

Side note: they published the increased speeds but word on the street is not all the timers have been upgraded, so the defacto speed limit remains in some places. 🤔

I’m pretty sure none of these changes involve changing timer speeds (thanks to our super conservative braking model) but instead just modifying signs. Some of them are in timed areas, yes, but for example the change on F3 at Barclays is to allow trains to speed up after they clear that one shot. Until they make substantive changes to their braking calcs, I wouldn’t hold your breath for many GT mods sadly...

Edited by RR503

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