WMATA Automatic Train Control

[mtuandrew]

YES! FINALLY! I don't quite understand why they're only going to be operating it during rush hours though. And why aren't they having six-car trains stop at the center of platforms?

Rush Hour only, probably because that’s where the most capacity can be gained. Doesn’t matter if a midday train is 30 seconds early or late.

As for front-of-platform stops, it’s probably much easier to program a common stop point regardless of car type or train length. Or, maybe Wiedefeld just wants commuters at L’Enfant to take up sprinting

[STrRedWolf]

YES! FINALLY! I don't quite understand why they're only going to be operating it during rush hours though. And why aren't they having six-car trains stop at the center of platforms?

Rush Hour only, probably because that’s where the most capacity can be gained. Doesn’t matter if a midday train is 30 seconds early or late.

As for front-of-platform stops, it’s probably much easier to program a common stop point regardless of car type or train length. Or, maybe Wiedefeld just wants commuters at L’Enfant to take up sprinting

That, and the manual operation has them going all the way up anyway (too many incidents). It was simpler to just have them go all the way up instead of stopping in the middle because it meant all of the train (6 or 8 cars) were matching the platform.

[KTHW]

I think WMATA has officially implemented ATO during rush hour again. Silver Line ride this morning was exceptionally smooth even with Excel/Decel in and out of station, and doors were opening the second the train came to a complete stop. My ride ended up being 10mins shorter than usual. I forgot how nice ATO is!

[daybeers]

I think WMATA has officially implemented ATO during rush hour again. Silver Line ride this morning was exceptionally smooth even with Excel/Decel in and out of station, and doors were opening the second the train came to a complete stop. My ride ended up being 10mins shorter than usual. I forgot how nice ATO is!

That's wonderful to hear!

[srepetsk]

I think WMATA has officially implemented ATO during rush hour again. Silver Line ride this morning was exceptionally smooth even with Excel/Decel in and out of station, and doors were opening the second the train came to a complete stop. My ride ended up being 10mins shorter than usual. I forgot how nice ATO is!

Auto-Doors is in certification, but ATO has not yet been reenabled.

[KTHW]

Thanks for the heads up, must of just had a the luck of a good day for WMATA. Related to this topic, what’s up with trains having to “adjust to the platform”? Sometimes a train stops 3-4 times while pulling in or out of a station.

[mtuandrew]

Thanks for the heads up, must of just had a the luck of a good day for WMATA. Related to this topic, what’s up with trains having to “adjust to the platform”? Sometimes a train stops 3-4 times while pulling in or out of a station.

Have wondered that myself - might be the specific operators, but it also seems linked to 7k cars as I haven’t had this experience on 2/3k or 6k cars.

[Robert Paniagua]

I wonder if and when ATC/ATO will resume in Metro

[Backshophoss]

What has worked for BART,as had not done well for WMATA,and in some cases failed with Fatalities.
It is possible that the whole automation system is so outdated it wont interface with the 7K's.
Are there segments that have operated with the ATO back online?

[Sand Box John]

"Backshophoss"
What has worked for BART,as had not done well for WMATA,and in some cases failed with Fatalities.

Comparing BART to WMATA is like comparing apples to oranges. Yes both provide for automatic operation, however the way it is implemented is different.

It is possible that the whole automation system is so outdated it wont interface with the 7K's.

The 7ks hear the same coded signals transmitted through the rails from wayside as the older rolling stock. The only difference is the electronics that converts those signal into acceleration, breaking and ok to open doors.

It is important to remember, Automatic Train Operation is a 100 percent train board function. Wayside simply enforces the safe spacing of trains by transmitting the appropriate speed command or no speed command.

[bulk88]

It is important to remember, Automatic Train Operation is a 100 percent train board function. Wayside simply enforces the safe spacing of trains by transmitting the appropriate speed command or no speed command.

From what I read DC ATO has "approach" hint given to the train, manual just causes penalty brake/SPAD/half e brake. Pulse code/audio freq code has current speed (ATS/ATP) and next code, next code isn't on the cab signal display but ATO can see it and pick the correct accel/brake curve. a manuel driver with just get a penalty brake and grind to a halt going through a more restricting block.

[Sand Box John]

bulk88
From what I read DC ATO has "approach" hint given to the train, manual just causes penalty brake/SPAD/half e brake. Pulse code/audio freq code has current speed (ATS/ATP) and next code, next code isn't on the cab signal display but ATO can see it and pick the correct accel/brake curve. a manuel driver with just get a penalty brake and grind to a halt going through a more restricting block.

Actually the operator is given a fixed amount of time to respond to a reduced speed command. That beeping sound you hear coming from the cab is the over speed alarm. If operator exceeds that fixed time the train will come to a halt. Service brake will cancel the alarm allowing the operator to slow to the reduced speed. Most locomotives with cab signal on common carrier railroad will do the same thing.

[bulk88]

Actually the operator is given a fixed amount of time to respond to a reduced speed command. That beeping sound you hear coming from the cab is the over speed alarm. If operator exceeds that fixed time the train will come to a halt. Service brake will cancel the alarm allowing the operator to slow to the reduced speed. Most locomotives with cab signal on common carrier railroad will do the same thing.

WMATA pulse code or CSX/NS pulse code? WMATA pulse code seems to de-motor and max service brake to zero mph before the driver can "re-motor". Its a problem around interlockings or merges. Station platform has a high speed code (45 mph), right at the platform edge, or 1 foot outside the station, there is a 0 mph code, driver full throttle accelerates out of the station, basically full service brake inducter hit 10 feet outside the platform, 60-100 feet later train is standing still for 5-15 seconds with first car in the tunnel, rear 4-5 cars still on platform, at 0 mph the beeping stops, and a 30 or 45 code the train gets and then accelerates away like normal. There is no alerter button to "acknowledge" and prevent a penalty brake mainline RR style and coast no motors until below the speed code for the block.

[Sand Box John]

bulk88
WMATA pulse code or CSX/NS pulse code? WMATA pulse code seems to de-motor and max service brake to zero mph before the driver can "re-motor". Its a problem around interlockings or merges. Station platform has a high speed code (45 mph), right at the platform edge, or 1 foot outside the station, there is a 0 mph code, driver full throttle accelerates out of the station, basically full service brake inducter hit 10 feet outside the platform, 60-100 feet later train is standing still for 5-15 seconds with first car in the tunnel, rear 4-5 cars still on platform, at 0 mph the beeping stops, and a 30 or 45 code the train gets and then accelerates away like normal. There is no alerter button to "acknowledge" and prevent a penalty brake mainline RR style and coast no motors until below the speed code for the block.

Your argument is based on the assumption that the train control system was designed for full time manual operation. Fact is it was designed for full time automatic operation. The train board automatic systems responds more gracefully to loss of speed commands then can be done by an operator in manual mode.

There is no such thing as a '0 mph code', the transmission of no speed commands or the receiving of no speed commands (loss of speed commands) is a fail safe that bring a train to a stop in both automatic or manual mode.

[YOLO]

NBC4 is reporting that Metro wants to restore ATO by late 2023. Automatic door operations to return "soon"

Tweet thread here too https://twitter.com/tomroussey7news/sta ... 8866022400

PDF: https://www.wmata.com/about/calendar/ev ... pdates.pdf