Why Your Subway Train Might Start Moving Faster

[RR503]

1 hour ago, Union Tpke said:

A line between the Broad Channel and Howard Beach stops.

Some limits removed coming off the north channel draw. 

This article is extremely disturbing. Those of us who foresaw this task force being a political vehicle with which Cuomo can take credit for Byford’s work are having are fears confirmed — and are seeing some of the most important parts of the Save Safe Seconds effort undermined by those who know jack shit about NYCT. 

As for the areas under review, they, like all other areas which received signal modifications, have legitimate safety issues. The inconvenient truth about timers is that they were necessary in some areas — they were value engineered into the next dimension, absolutely, and fed off of conservative assumptions about braking rates, but that doesn’t diminish the fact that there were safety issues that needed to be addressed. If they plan on going beyond simple recalibrations, fixing any of those areas will require either some relatively intensive capital work (new signals, new IJs, moved IJs, etc), or will entail replacing timer-enforcer safety with suuuper long control lines. One of my greatest concerns about this task force is that they will, in the course of serving Cuomo’s ends, either compromise safety or, in pursuit of speed, replace a bad signal mod with worse and reduce capacity. There isn’t much — if anything — we can do to stop it, but it’s worth keeping your eye peeled. 

Edited August 5, 2019 by RR503

[Union Tpke]

1 hour ago, RR503 said:

Some limits removed coming off the north channel draw. 

This article is extremely disturbing. Those of us who foresaw this task force being a political vehicle with which Cuomo can take credit for Byford’s work are having are fears confirmed — and are seeing some of the most important parts of the Save Safe Seconds effort undermined by those who know jack shit about NYCT. 

As for the areas under review, they, like all other areas which received signal modifications, have legitimate safety issues. The inconvenient truth about timers is that they were necessary in some areas — they were value engineered into the next dimension, absolutely, and fed off of conservative assumptions about braking rates, but that doesn’t diminish the fact that there were safety issues that needed to be addressed. If they plan on going beyond simple recalibrations, fixing any of those areas will require either some relatively intensive capital work (new signals, new IJs, moved IJs, etc), or will entail replacing timer-enforcer safety with suuuper long control lines. One of my greatest concerns about this task force is that they will, in the course of serving Cuomo’s ends, either compromise safety or, in pursuit of speed, replace a bad signal mod with worse and reduce capacity. There isn’t much — if anything — we can do to stop it, but it’s worth keeping your eye peeled. 

I agree. I still have some level of confidence that unsafe mods will not occur. Byford will not allow for it, and most of all, the TWU won't allow for it.

Do you know anything about these changes?:

They will include the A and C lines between the Lafayette Ave. and Liberty Ave. stations; the Nos. 2, 3, 4 and 5 lines between the Nevins St. and Utica Ave. stops; and trains running on the B, D, N and Q lines over the Manhattan Bridge, the sources said.

[RestrictOnTheHanger]

That Ronnie Hakim quote is something, considering she is well known for her earlier comments against speed

[Union Tpke]

4 minutes ago, RestrictOnTheHanger said:

That Ronnie Hakim quote is something, considering she is well known for her earlier comments against speed

Yup. She is a bureaucratic hack that needs to get out of the agency!

[RR503]

5 hours ago, Union Tpke said:

Do you know anything about these changes?

No, though given the sensitivity of this particular situation I'd imagine those who do know would be careful about sharing. The article certainly suggests that these mods are just calibration changes, though the purportedly significant increase in train speeds would seem a bit of an overstatement if that is the case...

5 hours ago, Union Tpke said:

I agree. I still have some level of confidence that unsafe mods will not occur. Byford will not allow for it, and most of all, the TWU won't allow for it.

I sure hope this is true! We really don't need to toe that line, what with the general railroad culture in the US being one of such caution. One mistake could bring the whole effort crashing down. 

 

[Union Tpke]

15 minutes ago, RR503 said:

No, though given the sensitivity of this particular situation I'd imagine those who do know would be careful about sharing. The article certainly suggests that these mods are just calibration changes, though the purportedly significant increase in train speeds would seem a bit of an overstatement if that is the case...

I sure hope this is true! We really don't need to toe that line, what with the general railroad culture in the US being one of such caution. One mistake could bring the whole effort crashing down. 

 

Agreed. The change on the Manhattan Bridge is interesting.

[R68OnBroadway]

Do they still have those Lafayette timers on the ?

[Lex]

7 hours ago, Union Tpke said:

I agree. I still have some level of confidence that unsafe mods will not occur. Byford will not allow for it, and most of all, the TWU won't allow for it.

Do you know anything about these changes?:

They will include the A and C lines between the Lafayette Ave. and Liberty Ave. stations; the Nos. 2, 3, 4 and 5 lines between the Nevins St. and Utica Ave. stops; and trains running on the B, D, N and Q lines over the Manhattan Bridge, the sources said.

At that point, we'd be better off burying the crossings than keeping them on the bridge.

[RR503]

40 minutes ago, Lex said:

At that point, we'd be better off burying the crossings than keeping them on the bridge.

Do explain...

[Lex]

19 minutes ago, RR503 said:

Do explain...

The Manhattan Bridge's inherent design flaws severely limit speeds across it (to the point where the only reasons for being faster than Lexington Avenue are the entry into/exit from Manhattan and the lack of stops between Manhattan and DeKalb Avenue), and unlike the Williamsburg Bridge, neither end involves already-elevated tracks. The switches on the Brooklyn end do no favors, though that's more of a symptom of trains arriving at inconvenient times (rather than consistent / and / arrivals, trains show up whenever) than anything else.

Due to the aforementioned design flaws, trains across the bridge don't typically break 25 mph, whereas it would be easier (and safer) to foster speeds around 35-40 mph in tunnels (which would also allow trains to clear the switches sooner by virtue of the other blocks being occupied for shorter periods). Moreover, having the trains in tunnels will help to avoid compromising the structure of a truck route.

Now if only we could get some designs and construction going at a good pace...

[R68OnBroadway]

Rebuilding a tunnel for the Manhattan seems like overkill, the only thing to be fixed is to trust T/Os to hit the right route on the punch box at DeKalb (which should help speed up that area). An area that could use a tunnel though would be the Williamsburg-the curves near the bridge do no favors and a 3 or 4 track tunnel would be better than the slow bridge we have today.

[Union Tpke]

2 hours ago, Lex said:

At that point, we'd be better off burying the crossings than keeping them on the bridge.

There have been proposals in the 1950s to replace it with multiple tunnels, and one in the 1990s to connect the Culver Line to the Brighton Line. This was part of the East River Crossings Study I have been itching to look at. It was seriously considered when there were doubts that the bridge would hold up.

I have been working on an article titled Manhattan Bridge subway closure with Epicgenius about it here:

https://en.wikipedia.org/wiki/User:Epicgenius/sandbox/draft5

This is something I copied about the study that I will later paraphrase and add to the draft article.

https://en.wikipedia.org/wiki/User:Kew_Gardens_613/sandbox_5#Rutgers_Street_Tunnel–DeKalb_Avenue_Track_Connection

 

[Lex]

29 minutes ago, R68OnBroadway said:

Rebuilding a tunnel for the Manhattan seems like overkill, the only thing to be fixed is to trust T/Os to hit the right route on the punch box at DeKalb (which should help speed up that area).

It's most certainly not. Safety is the whole reason why trains crawl on the bridge, and that negatively impacts being able to clear the switches.

Also, it should be of considerable concern that we're still not using something that can render punchboxes obsolete.

[RR503]

1 hour ago, Lex said:

The Manhattan Bridge's inherent design flaws severely limit speeds across it (to the point where the only reasons for being faster than Lexington Avenue are the entry into/exit from Manhattan and the lack of stops between Manhattan and DeKalb Avenue), and unlike the Williamsburg Bridge, neither end involves already-elevated tracks. The switches on the Brooklyn end do no favors, though that's more of a symptom of trains arriving at inconvenient times (rather than consistent / and / arrivals, trains show up whenever) than anything else.

Due to the aforementioned design flaws, trains across the bridge don't typically break 25 mph, whereas it would be easier (and safer) to foster speeds around 35-40 mph in tunnels (which would also allow trains to clear the switches sooner by virtue of the other blocks being occupied for shorter periods). Moreover, having the trains in tunnels will help to avoid compromising the structure of a truck route.

Now if only we could get some designs and construction going at a good pace...

Tunnels certainly would be faster, but I’m not sure this investment pans out. The real killer on the bridge route isn’t so much the bridge itself (which, mind you, is rarely actually taken at 25 because of equipment performance and signaling issues), but as you say the junction south of it. Without getting too in the weeds on signal design, there are a lot of areas of track in Dekalb that are signaled at artificially low speeds to protect approach signals, short control lines, certain curve configurations and — and this will sound counterintuitive — to increase capacity. CBTC, or any resignalling that allows for more aggressive train speed programming, would likely realize significant travel time improvements in the area, improvements that can be made irrespective of the sort of crossing attached to the northern end. 

[RR503]

3 minutes ago, Lex said:

It's most certainly not. Safety is the whole reason why trains crawl on the bridge, and that negatively impacts being able to clear the switches.

Also, it should be of considerable concern that we're still not using something that can render punchboxes obsolete.

To be fair, though, it’s not geometric or even structural safety that forces the slower speeds in the area, but rather the need to enforce safety relative to the existing signal system. 

On the second part, I’m with ya, though again it isn’t the punchboxes that cause the issue, but rather the CCTV system that was added to corroborate punches. 

[Gotham Bus Co.]

11 hours ago, Union Tpke said:

They will include the A and C lines between the Lafayette Ave. and Liberty Ave. stations; the Nos. 2, 3, 4 and 5 lines between the Nevins St. and Utica Ave. stops; and trains running on the B, D, N and Q lines over the Manhattan Bridge, the sources said.

 

Will the schedules be revised? Or will even more trains just hold along the way to make up the saved time?

[Union Tpke]

1 minute ago, Gotham Bus Co. said:

 

Will the schedules be revised? Or will even more trains just hold along the way to make up the saved time?

I doubt the schedules will be revised. Anyhow, it will make OTP look better.

[Union Tpke]

25 minutes ago, RR503 said:

Tunnels certainly would be faster, but I’m not sure this investment pans out. The real killer on the bridge route isn’t so much the bridge itself (which, mind you, is rarely actually taken at 25 because of equipment performance and signaling issues), but as you say the junction south of it. Without getting too in the weeds on signal design, there are a lot of areas of track in Dekalb that are signaled at artificially low speeds to protect approach signals, short control lines, certain curve configurations and — and this will sound counterintuitive — to increase capacity. CBTC, or any resignalling that allows for more aggressive train speed programming, would likely realize significant travel time improvements in the area, improvements that can be made irrespective of the sort of crossing attached to the northern end. 

First, what equipment performance issues prevent trains from reaching 25? Second of all, how much time do you think could be saved, on let's say an  train through DeKalb with CBTC?

[RR503]

3 minutes ago, Union Tpke said:

First, what equipment performance issues prevent trains from reaching 25?

R68s significantly underperform on uphills, which is a big issue in the Dekalb area.

4 minutes ago, Union Tpke said:

Second of all, how much time do you think could be saved, on let's say an  train through DeKalb with CBTC?

At least 2-3 minutes, likely more, though I'd imagine you'd gain more sb than nb. Today, we schedule 11-12 mins Canal-Atlantic, and the 25th percentile runtime is already around 10:30 mins. If you can do away with some of those speed restrictions coming into Dekalb, I see no reason why 7 or 8ish wouldn't be possible.

[R68OnBroadway]

9 minutes ago, RR503 said:

R68s significantly underperform on uphills, which is a big issue in the Dekalb area.

That explains why the sb  always crawls around Avenue H... I always assumed it was because local operators accelerated and braked fast while expresses accelerated and braked gradually...

[Trainmaster5]

Does anyone remember why the Manhattan Bridge suffered through the shutdowns and partial closures ? Simply put, the Williamsburg, and before that, the Brooklyn Bridge were constructed in a manner more conducive to streetcar, rail car, use. We’re probably lucky that the bridge still allows any rail traffic if you remember the studies done about the integrity of the structure. IIRC that was the reasoning behind the different shutdowns. I don’t know how that impacts the speed argument but I’m almost sure that it plays a part. Just my opinion. Carry on.

[R68OnBroadway]

5 minutes ago, Trainmaster5 said:

Does anyone remember why the Manhattan Bridge suffered through the shutdowns and partial closures ? Simply put, the Williamsburg, and before that, the Brooklyn Bridge were constructed in a manner more conducive to streetcar, rail car, use. We’re probably lucky that the bridge still allows any rail traffic if you remember the studies done about the integrity of the structure. IIRC that was the reasoning behind the different shutdowns. I don’t know how that impacts the speed argument but I’m almost sure that it plays a part. Just my opinion. Carry on.

I thought the issue with the WillyB was because they were cheap and used ungalvinized steel (which ended up degrading with the weather and pigeon droppings).

[RR503]

10 minutes ago, Trainmaster5 said:

Does anyone remember why the Manhattan Bridge suffered through the shutdowns and partial closures ? Simply put, the Williamsburg, and before that, the Brooklyn Bridge were constructed in a manner more conducive to streetcar, rail car, use. We’re probably lucky that the bridge still allows any rail traffic if you remember the studies done about the integrity of the structure. IIRC that was the reasoning behind the different shutdowns. I don’t know how that impacts the speed argument but I’m almost sure that it plays a part. Just my opinion. Carry on.

Yeah, the Manhattan Bridge's structure and initial rapid transit operating plan were garbage. Putting your heaviest loads (subway trains) far from the centerline of the structure means you get a good bit of twisting when the load passes over. Throw in the fact that the north tracks were used much more than the southern tracks from opening day really until the shutdowns started (remember, the Chrystie operating plan didn't run all that much full time service up Broadway), and you developed assymetrical fatigue, worsened by deferred maintenance and a lack of stiffness in the bridge's floor. If I'm not mistaken, that was the real driver of all the structural work they did on the span in the 80s, 90s and aughts. 

As for the speed issue, I remember reading somewhere that the bridge's tracks were initially (or maybe were designed assuming?) an operating speed of 35mph, but that speed was reduced to 25 to ensure stability and reduce wear -- 35 means stronger, faster twisting. TM5, do you know anything about this?

[RestrictOnTheHanger]

The new "countdown timer" attached to the one shot south of 34th st on the s/b 8th Ave local track operates a little differently than the ones at Atlantic Ave and Times Sq. The one shot clears immediately as the countdown hits zero, no delay like on the others

[RestrictOnTheHanger]

The 2 shot GTs between City Hall and Canal on the n/b definitely need recalibrating. Passed through a few minutes ago. Despite the increased civil speed limit right after City Hall, the timers havent been adjusted and clear at way less than the posted speed. 

Edited August 12, 2019 by RestrictOnTheHanger