CBTC - General Discussion

[RR503]

Most everyone I’ve talked to has had the impression has been that  ATO is less aggressive than  ATO. The extent to which this is normal distortion versus actual fact, I dunno. I’d hope that this is still all under review.  

[Union Tpke]

1 hour ago, RR503 said:

Most everyone I’ve talked to has had the impression has been that  ATO is less aggressive than  ATO. The extent to which this is normal distortion versus actual fact, I dunno. I’d hope that this is still all under review.  

What does less aggressive mean?

[Union Tpke]

2 hours ago, Enjineer said:

Alright, got a quick response: I was told that they lowered some speeds in the Steinway Tubes, as well as heading southbound (Manhattan-bound, I assume) into 52nd Street and 33rd Street. For 52nd and 33rd, I'd assume it's for safety regarding the curves past both stations. 

@RR503@EnjineerIf they are unsafe, I don't understand why the speeds were lowered during the speed lowering blitz of the '90s. Why would they lower it in the tubes?

[RR503]

10 minutes ago, Union Tpke said:

What does less aggressive mean?

As in trains move more slowly/brake more conservatively, etc.

9 minutes ago, Union Tpke said:

@RR503@EnjineerIf they are unsafe, I don't understand why the speeds were lowered during the speed lowering blitz of the '90s. Why would they lower it in the tubes?

Remember, the mods contract was never finished. It's within the realm of possibility that they meant to but didn't. 

[Union Tpke]

31 minutes ago, RR503 said:

As in trains move more slowly/brake more conservatively, etc.

Remember, the mods contract was never finished. It's within the realm of possibility that they meant to but didn't. 

 

What would be the rationale in having trains move slowly/brake more conservatively?

You are probably right.

 

 

The Dashboard was finally updated!

http://web.mta.info/capitaldashboard/allframenew_pi.php?PROJNUM=t7080342&PLTYPE=4

http://web.mta.info/capitaldashboard/allframenew_budhist.php?PROJNUM=t7080342&PLTYPE=4

T7080342

CBTC: Carborne Equipment Purchase

This project will purchase CBTC carborne equipment for various railcar classes (R211, R160, R179) to coincide with CBTC installation on the 8 Avenue Line.

This project was split-out from the "Install Communication-Based Train Control (CBTC) on the 8 Avenue Line from 59 Street to High Street" project.

$82,594,943

[Union Tpke]

@RR503 Notice that no location is listed.

http://web.mta.info/capitaldashboard/allframenew_pi.php?PROJNUM=t7080338&PLTYPE=5

http://web.mta.info/capitaldashboard/allframenew_budget.php?PROJNUM=t7080338&PLTYPE=5

http://web.mta.info/capitaldashboard/allframenew_budhist.php?PROJNUM=t7080338&PLTYPE=5

T7080338

Signal Technology Upgrades

This project is a budgetary reserve that will provide design and construction funding for individual signal technology upgrade projects.

 The budget was reduced to split-out a new subproject, "Ultra-Wideband Based Train Control Pilot Program".

 

 

http://web.mta.info/capitaldashboard/allframenew_pi.php?PROJNUM=t7080346&PLTYPE=6

http://web.mta.info/capitaldashboard/allframenew_budget.php?PROJNUM=t7080346&PLTYPE=6

http://web.mta.info/capitaldashboard/allframenew_budhist.php?PROJNUM=t7080346&PLTYPE=6

T7080346

Ultra-Wideband Based Train Control Pilot Program

This project provides for the testing and evaluation of an Ultra-Wideband Train Control System.

Construction Start Mar 2019 End Dec 2019

$40,597,411

[Enjineer]

2 hours ago, RR503 said:

Most everyone I’ve talked to has had the impression has been that  ATO is less aggressive than  ATO. The extent to which this is normal distortion versus actual fact, I dunno. I’d hope that this is still all under review.

In general I think the  just has a smoother acceleration curve. The  has always been very janky, and I think they probably designed the 's ATO with more comfort in mind, while balancing it with speed and efficiency

[ibroketheprinter]

1 minute ago, Enjineer said:

In general I think the  just has a smoother acceleration curve. The  has always been very janky, and I think they probably designed the 's ATO with more comfort in mind, while balancing it with speed and efficiency

Is this purely because of the physical layout of the line, or the nature of the equipment on the line?

[RR503]

24 minutes ago, Union Tpke said:

What would be the rationale in having trains move slowly/brake more conservatively?

Comfort, which of course comes at the expense of capacity here. The faster you can get trains in/out of stations, the better. 

[Union Tpke]

Just now, RR503 said:

Comfort, which of course comes at the expense of capacity here. The faster you can get trains in/out of stations, the better. 

Idiots. Is there any way to change this?

[RR503]

3 minutes ago, Union Tpke said:

Idiots. Is there any way to change this?

I'd assume so, though I can't speak to the technical aspects of how. 

[Enjineer]

19 minutes ago, ibroketheprinter said:

Is this purely because of the physical layout of the line, or the nature of the equipment on the line?

Neither. I think it's purely because a smoother acceleration curve provides a nicer ride. The  always seems to just immediately zip out of stations, and can be quite hard on the brakes sometimes. Assuming it's smoother on the , trains would still go nice and fast, but wouldn't do the equivalent of flooring it or SLAMMING on the brakes. Also, I think the changes here are really minor; I don't think it's anywhere near enough difference that they'd be able to add more trains or something if the curves were set to have trains accelerate as fast as possible as soon as possible. For all I know, a smoother curve could mean just not immediately doing full power, and rather taking 2-3 seconds to increase power to full as to provide a smoother transition from standing to accelerating, and vice versa for braking. 

Edited May 9, 2019 by Enjineer

[RR503]

9 minutes ago, Enjineer said:

Neither. I think it's purely because a smoother acceleration curve provides a nicer ride. The  always seems to just immediately zip out of stations, and can be quite hard on the brakes sometimes. Assuming it's smoother on the , trains would still go nice and fast, but wouldn't do the equivalent of flooring it or SLAMMING on the brakes. Also, I think the changes here are really minor; I don't think it's anywhere near enough difference that they'd be able to add more trains or something if the curves were set to have trains accelerate as fast as possible as soon as possible. For all I know, a smoother curve could mean just not immediately doing full power, and rather taking 2-3 seconds to increase power to full as to provide a smoother transition from standing to accelerating, and vice versa for braking. 

It makes a difference. If you're spending an extra 3 seconds entering a station and an extra 3 seconds leaving, you just added six seconds to your cycle time, which is the difference between 30 and 28.5 tph. The "seconds" part of Save Safe Seconds isn't a joke; little things really do add up.

[Enjineer]

14 hours ago, RR503 said:

It makes a difference. If you're spending an extra 3 seconds entering a station and an extra 3 seconds leaving, you just added six seconds to your cycle time, which is the difference between 30 and 28.5 tph. The "seconds" part of Save Safe Seconds isn't a joke; little things really do add up.

Well I'll be (hopefully) riding the  this PM rush with a friend to check out the ATO operation. I'll be sure to report back if the acceleration/deceleration seems to be noticeably different compared to ATP-M operation and the 's ATO. I don't know if it was just me, but I felt that once the  was cutover to full CBTC, the acceleration curves on the R188's motors were adjusted to be faster, so I'm not sure if this means they've now altered the curves again with ATO.

Edited May 10, 2019 by Enjineer

[Union Tpke]

http://www.mta.info/press-release/nyc-transit/new-system-faster-more-reliable-service-comes-flushing-line

MORE ABOUT IMPROVED SERVICE ON THE FLUSHING LINE

Since CBTC was installed in December 2018, service has improved steadily each month.

ATO and CBTC have also helped NYC Transit increase the number of peak trains per hour on the  line, to 29 from 25-27, providing service for an additional 2,400 to 4,800 people per hour.

On-time performance numbers have gone from 74.7% the month before CBTC was installed to 91.% in March 2019. A year ago in March 2018, on-time performance was just 55.5%.

In November 2018, service delivered (the percentage of scheduled trains that are actually provided during peak hours) on the  line was 89.3%. The month after CBTC was installed it rose to 95%, increasing further to 96.8% in March.

Major incidents, or those that delay 50 or more trains, have also decreased drastically. There were an average 8 monthly major incidents between January and November 2018.  December 2018 to March 2019 there was a monthly average of 2.75.

Additional train time, a metric detailing the average time customers spend onboard a train beyond their scheduled travel time, has gone down dramatically, from 1m40s in November 2018 to just 31 seconds in March 2019.

Why can't this lead to 33 TPH like what was done during the 2000 World's Series?

Incompetence.

[danielhg121]

16 minutes ago, Union Tpke said:

http://www.mta.info/press-release/nyc-transit/new-system-faster-more-reliable-service-comes-flushing-line

MORE ABOUT IMPROVED SERVICE ON THE FLUSHING LINE

Since CBTC was installed in December 2018, service has improved steadily each month.

ATO and CBTC have also helped NYC Transit increase the number of peak trains per hour on the  line, to 29 from 25-27, providing service for an additional 2,400 to 4,800 people per hour.

On-time performance numbers have gone from 74.7% the month before CBTC was installed to 91.% in March 2019. A year ago in March 2018, on-time performance was just 55.5%.

In November 2018, service delivered (the percentage of scheduled trains that are actually provided during peak hours) on the  line was 89.3%. The month after CBTC was installed it rose to 95%, increasing further to 96.8% in March.

Major incidents, or those that delay 50 or more trains, have also decreased drastically. There were an average 8 monthly major incidents between January and November 2018.  December 2018 to March 2019 there was a monthly average of 2.75.

Additional train time, a metric detailing the average time customers spend onboard a train beyond their scheduled travel time, has gone down dramatically, from 1m40s in November 2018 to just 31 seconds in March 2019.

Why can't this lead to 33 TPH like what was done during the 2000 World's Series?

Incompetence.

Dispatchers at Main can't get their shit together...    

[Enjineer]

1 hour ago, Union Tpke said:

Why can't this lead to 33 TPH like what was done during the 2000 World's Series?

Didn't the latest supplement as of April 28th for the L project give the  about a 50 minute period during each rush hour with 32 tph frequencies? 

[RR503]

1 hour ago, Enjineer said:

Well I'll be (hopefully) riding the  this PM rush with a friend to check out the ATO operation. I'll be sure to report back if the acceleration/deceleration seems to be noticeably different compared to ATP-M operation and the 's ATO. I don't know if it was just me, but I felt that once the  was cutover to full CBTC, the acceleration curves on the R188's motors were adjusted to be faster, so I'm not sure if this means they've now altered the curves again with ATO.

Trains definitely got faster. Equipment in the system actually follows two acceleration profiles: a ‘cold curve,’ which applies to operations in areas controlled by legacy fixed blocks, and a ‘hot curve,’  which governs acceleration in areas with active CBTC (ATPM or ATO). AFAIK  and  trains follow the same hot curve, so their profiles in absence of speed limits should be the same. It seems to be profile of the limit curve that kills . 

2 hours ago, Union Tpke said:

http://www.mta.info/press-release/nyc-transit/new-system-faster-more-reliable-service-comes-flushing-line

MORE ABOUT IMPROVED SERVICE ON THE FLUSHING LINE

Since CBTC was installed in December 2018, service has improved steadily each month.

ATO and CBTC have also helped NYC Transit increase the number of peak trains per hour on the  line, to 29 from 25-27, providing service for an additional 2,400 to 4,800 people per hour.

On-time performance numbers have gone from 74.7% the month before CBTC was installed to 91.% in March 2019. A year ago in March 2018, on-time performance was just 55.5%.

In November 2018, service delivered (the percentage of scheduled trains that are actually provided during peak hours) on the  line was 89.3%. The month after CBTC was installed it rose to 95%, increasing further to 96.8% in March.

Major incidents, or those that delay 50 or more trains, have also decreased drastically. There were an average 8 monthly major incidents between January and November 2018.  December 2018 to March 2019 there was a monthly average of 2.75.

Additional train time, a metric detailing the average time customers spend onboard a train beyond their scheduled travel time, has gone down dramatically, from 1m40s in November 2018 to just 31 seconds in March 2019.

Why can't this lead to 33 TPH like what was done during the 2000 World's Series?

Incompetence.

To be fair, CBTC/ATO do have real benefits — faster service, flexible train spacing, more operational consistency. The unspectacular throughputs, though, are absolutely an issue. To spend this much and gain so little in capacity is...sad. What limits on Flushing is dwell time now, so sadly fixing this will require a bit more rigor than just activating CBTC. 

[Enjineer]

2 hours ago, RR503 said:

What limits on Flushing is dwell time now, so sadly fixing this will require a bit more rigor than just activating CBTC. 

Right. Being uninterlined and isolated already helped Flushing just have a good amount of trains without CBTC. That report about service improvements also isn't incorporating the new supplements as it was from the end of March. As I stated previously, the L project supplement for the  has now increased the maximum scheduled TPH to 32. 

[RR503]

1 hour ago, Enjineer said:

Right. Being uninterlined and isolated already helped Flushing just have a good amount of trains without CBTC. That report about service improvements also isn't incorporating the new supplements as it was from the end of March. As I stated previously, the L project supplement for the  has now increased the maximum scheduled TPH to 32. 

Most I'm getting in any given 50m period during the AM is the equivalent of a 30tph rate. I'm measuring at GC. What's your methodology? 

[Enjineer]

14 minutes ago, RR503 said:

Most I'm getting in any given 50m period during the AM is the equivalent of a 30tph rate. I'm measuring at GC. What's your methodology? 

You're right, whoops! When they adjusted the timetables, someone had pointed out that the 7 was now the most frequent line with 32 tph – lo and behold I went back to the post I had seen that number in the first place and the person had edited it back to 30 and said "whoops, bad math!" Sorry about that 

[RR503]

1 minute ago, Enjineer said:

You're right, whoops! When they adjusted the timetables, someone had pointed out that the 7 was now the most frequent line with 32 tph – lo and behold I went back to the post I had seen that number in the first place and the person had edited it back to 30 and said "whoops, bad math!" Sorry about that 

No no, no worries! I love a good discussion on schedules lol 

[Enjineer]

10 minutes ago, RR503 said:

No no, no worries! I love a good discussion on schedules lol 

On the topic before about the curves and whatnot for acceleration, I'm heading to the  as soon as I post this, so I'll be able to report back later if anything feels noticeably different. I'll also try and get a glimpse of the CBTC screens to indeed confirm that they're running in ATO. 

[Union Tpke]

5 hours ago, RR503 said:

Trains definitely got faster. Equipment in the system actually follows two acceleration profiles: a ‘cold curve,’ which applies to operations in areas controlled by legacy fixed blocks, and a ‘hot curve,’  which governs acceleration in areas with active CBTC (ATPM or ATO). AFAIK  and  trains follow the same hot curve, so their profiles in absence of speed limits should be the same. It seems to be profile of the limit curve that kills . 

To be fair, CBTC/ATO do have real benefits — faster service, flexible train spacing, more operational consistency. The unspectacular throughputs, though, are absolutely an issue. To spend this much and gain so little in capacity is...sad. What limits on Flushing is dwell time now, so sadly fixing this will require a bit more rigor than just activating CBTC. 

This begs the question: how was dwell time handled in the 1950s?

[Enjineer]

So: after riding the , the first thing I noticed was areas like the curve into Queensboro had the clear sign of ATO: constant small throttle applications to maintain a speed. I could clearly see ATO active on the screens, but overall everything seemed very smooth. I mostly noticed expresses were incredibly consistent between Woodside and Junction Blvd. Watching them pass 90th Street, they all seemed to be hitting their target speeds of 50 MPH and holding there, whereas before depending on the operator you could have trains running between 40-50 MPH.