Automated Train Brake Effectiveness

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Automated Train Brake Effectiveness
Posted by SteveSullivan on Tuesday, May 19, 2020 10:36 AM

In light of the recent news regarding CP's switching from the No. 1 brake test to Automated Train Brake Effectiveness, I'd love to hear a non-technical explanation of what Automated Train Brake Effectiveness is and how it differs from the original test. That procedure that is such a daily part of railroader's lives would be interesting to know more about too. 

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Posted by Overmod on Thursday, May 21, 2020 3:48 PM

As a quick intro: the #1 brake test is a static test, requiring inspectors on the ground; the ATBE is a rolling test involving wayside detector installations.  Here is a link to a PDF describing the approach in 2011.

Note that the current 'expansion' of ATBE is not 'new', but in response to the recent accident.  See here for more information perhaps more useful to you after reading the above.

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Posted by jeffhergert on Thursday, May 21, 2020 8:06 PM

UP was, maybe still is, testing something like this on some coal trains.  It extends the time between 'normal' air brake tests.

I'm skeptical about it being any safer.  It will allow them to need less car men.  

Jeff

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Posted by tree68 on Thursday, May 21, 2020 8:18 PM

While I suppose effectiveness (along with full release) is the most important measure, I would opine that things like worn shoes and loose parts aren't going to be detected by the machines.

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Posted by BaltACD on Thursday, May 21, 2020 10:46 PM

Isn't it still required of a crew upon taking charge of a train after departure from the origin termina or after a crew change for a running air test to be made for the Engineer to judge the effectiveness of the train brakes?

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Posted by Overmod on Friday, May 22, 2020 1:11 AM

tree68
While I suppose effectiveness (along with full release) is the most important measure, I would opine that things like worn shoes and loose parts aren't going to be detected by the machines.

You might design the wayside equipment to do more along these lines, but the point is that the ATBE is doing one thing: it's reading the effective degree of braking by the amount of heat generated (using the same detection that would give hot bearing indication combined with WILD or similar indication of axle position, so it can distinguish brake heat from potential bearing heat).

If the brakes are working, the effect will show up as heat.  Less heat, or (with a bit better matrix or staring detector construction) heat in the wrong places, will tell you how well the brakes approximate what they're supposed to be doing, and if any particular brake shoe is doing too much or too little 'share' of the job.  Much of this might not be evident in a stationary examination or 'human' rollby test -- and it can be repeated at each successive detector array, every 30 miles or so, as the train progresses.

I don't think it's intended to replace static examinations of equipment, although (as with the computerized track analysis on BNSF and elsewhere) it might extend the period between some parts of current mandatory inspection when operation shows 'no obvious defects'.  What it does do, and I think pretty well, is to substitute sequential running brake tests for the single simplistic, and as we now have seen sometimes inadequate, brake test conducted when starting.

To me, a lot of importance hinges on how the crew gets the reporting from the automated system.  Presumably it will continue to say 'no defects' or something like 'hot brake axle 58' but one has to wonder how well the system is adjusted for things like poor weather or different consists or equipment type.

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Posted by BaltACD on Friday, May 22, 2020 2:30 AM

Overmod
I don't think it's intended to replace static examinations of equipment, although (as with the computerized track analysis on BNSF and elsewhere) it might extend the period between some parts of current mandatory inspection when operation shows 'no obvious defects'.  What it does do, and I think pretty well, is to substitute sequential running brake tests for the single simplistic, and as we now have seen sometimes inadequate, brake test conducted when starting.

To me, a lot of importance hinges on how the crew gets the reporting from the automated system.  Presumably it will continue to say 'no defects' or something like 'hot brake axle 58' but one has to wonder how well the system is adjusted for things like poor weather or different consists or equipment type.

If the carriers get a inch - they will work it as a mile.  The Class 1 brake test is looking for fixable braking conditions such as worn shoes causing excessive piston travel as an example.

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Posted by BigJim on Saturday, May 23, 2020 12:39 PM

Overmod
I don't think it's intended to replace static examinations of equipment,


Keep dreaming! They will find a way to cut someone's job, just you watch! I've watched it happen for over forty years!

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Posted by charlie hebdo on Saturday, May 23, 2020 1:03 PM

Overmod

 

 
tree68
While I suppose effectiveness (along with full release) is the most important measure, I would opine that things like worn shoes and loose parts aren't going to be detected by the machines.

 

You might design the wayside equipment to do more along these lines, but the point is that the ATBE is doing one thing: it's reading the effective degree of braking by the amount of heat generated (using the same detection that would give hot bearing indication combined with WILD or similar indication of axle position, so it can distinguish brake heat from potential bearing heat).

If the brakes are working, the effect will show up as heat.  Less heat, or (with a bit better matrix or staring detector construction) heat in the wrong places, will tell you how well the brakes approximate what they're supposed to be doing, and if any particular brake shoe is doing too much or too little 'share' of the job.  Much of this might not be evident in a stationary examination or 'human' rollby test -- and it can be repeated at each successive detector array, every 30 miles or so, as the train progresses.

I don't think it's intended to replace static examinations of equipment, although (as with the computerized track analysis on BNSF and elsewhere) it might extend the period between some parts of current mandatory inspection when operation shows 'no obvious defects'.  What it does do, and I think pretty well, is to substitute sequential running brake tests for the single simplistic, and as we now have seen sometimes inadequate, brake test conducted when starting.

To me, a lot of importance hinges on how the crew gets the reporting from the automated system.  Presumably it will continue to say 'no defects' or something like 'hot brake axle 58' but one has to wonder how well the system is adjusted for things like poor weather or different consists or equipment type.

 

From what OM has described,  the automated test is 1.different than the static test in term of function; and 2. able to detect more precisely and frequently a wider variety of mechanical problems. 

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Posted by Overmod on Saturday, May 23, 2020 4:32 PM

BaltACD
If the carriers get a inch - they will work it as a mile.  The Class 1 brake test is looking for fixable braking conditions such as worn shoes causing excessive piston travel as an example.

This is a reason I don't look at this quite as pessimisticallly as Big Jim does.

Theoretically (and I say this as someone who has actually worked through what is required and periodically reviews the literature and suppliers that facilitate it) you could build a sensor-fused 'detector farm' that would be capable of polyspectral imaging with rapid high resolution (in other words, high-resolution video overlaid on IR heat information) which could detect things like brakeshoe gap, heat profile in wheelrims and shoes, commanded cylinder position under the car (and perhaps some of the valve positions or equipment condition, or telltales/gauges installed for waysides as well as inspectors to read) and thereby do a better job of assessing some of the things a good rollby examination can determine.

But it is questionable (in my opinion) that something like this can reliably test things like slack-adjuster position, or wear, or play in various joints; it is even more questionable that some method of one-pipe operation could be conceived that would 'exercise' the brake gear from release up to engagement repeatedly (and much more rapidly than even ECP should cycle) for the automated system to 'watch' and analyze.  (Likewise the amount of equipment necessary for, let's say, drone-based "inspectors" to fly up and back during a #1 test even to observe the minimum proposed for this, i.e. full shoe applications and then full running release at the shoes, while mirroring the video and sense data to the crew, gets to be a little extreme.)

The automated test relies explicitly on equipment already in place (and reasonably cost-effectively upgradable both in terms of the equipment and the datastream communications it will use) which is fixed and reasonably armored, and that depends on a moving train for its 'scanning'.  A limited amount of multiaxis pan and tilt could be built into this ... at relatively severe cost in a number of respects, even before the conspiracy hatches (pun, regrettably, somewhat intended) between the spiders at the Rochelle cam and their many railfan sisters elsewhere along rights-of-way...

I think the use of cheap Mk. 1 organic visual-capture devices combined with Mk 1 ambulatory sensing platforms is likely to persist for any required originating brake test on a 'new consist' (or for 'new' portions of one that has had blocks switched in or out) whether or not fancy drone support is provided to facilitate (and record) application and release in a running test -- as I think it probably should be.  And there is not much substitute for a physical inspection of cars 'up close and personal' on some reasonably regular basis as they run, and of course if a defect is reported on them (correctly or artifactually!) by one of the automated systems.  

Something I do expect is for the software programmers and architects that are conducting the automated ROW testing (which is like the contrapositive of the ATBE systems; the train and sensors move and 'scroll' along the thing being 'inspected') to make the logical analysis for what is, and isn't, properly in the scope of the 'safe way' to conduct inspections.  And for various lobbying, some sensible and some thoroughly wack, to be conducted on susceptible political entities including folks at DOT/FRA and other various regulatory agencies.

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Posted by Lithonia Operator on Saturday, May 23, 2020 9:44 PM

Mention was made of having this equipment, for example, every thirty miles. Does this mean that a brake application has to be in effect when the first car of a train passes the sensor, and the application continue (and remain at the same reduction level) until the last car goes by?

It would seem to me that a long train might stop before the last car passes the sensor. It also seems like the early cars' wheels would be tested at a much higher RPM than the tail end cars; and I would think that this discrepancy would make the data useless. A shoe pressing on a fast-turning wheel at X pressure would be much hotter than a shoe pressing with same pressure on a slow turner.

Obviously I don't get this at all (ya think?). Could someone provide a link to a diagram, animation or video of this equipment/process.

Despite knowing zip about this, I would think that if this supplements the regular, traditional test, then that can only be a good thing.

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Posted by tree68 on Saturday, May 23, 2020 11:32 PM

As I recall, the proposed application involved spots where a brake application would normally be used.   I would imagine that if the concept gained widespread approval, sensors that were measuring for heat from an application would be locatd where that was the case.

In my experience, defect detectors aren't usually located where a stop would be expected (I'll gladly stand corrected), ie, entering a yard, near industries.  As such, trains would normally be passing the detectors "at speed."  "Normal" detectors would serve to look for heat where there shouldn't be.  I believe they do that now, looking for failing bearings.  Adding parameters for hot wheels should be fairly easy, although it could also require new sensors.

Something like an emergency application (or any application, for that matter) when passing a detector would no doubt show up as an anomoly, but one easily explained.

The software could easily be made to adjust for a slow rise in the detected temperature such as might be found with a service application.  Ditto (in reverse) for an application released while the train was passing a detector.

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Posted by Overmod on Saturday, May 23, 2020 11:45 PM

Lithonia Operator
Obviously I don't get this at all (ya think?). Could someone provide a link to a diagram, animation or video of this equipment/process.

Did you download and read the 2011 PDF I linked earlier?

The original version of the ATBE equates brake effectiveness with higher viewed wheelrim temperature -- so one thing it's looking for will be 'outliers' in average wheel temperature.  Note that the 'hot wheel detectors' here are different from hotbox detectors, and setup that detects 'cold wheels' is different from that for 'hot wheels' (this may indicate different IR sensitivities, but the material is not specific on this) and the cold and hot wheel detections are not done at the same place.  See section 3.2ff for some of what the technical equipment does.

Surprisingly although the early description notes what a WILD is, the discussion does not appear to consider sensor fusion of the information from WILDs or microphones with the results of wheel scanning for brake 'effectiveness'.  This may have changed in the near-decade CP has been working with the approach, as I expect would the capabilities of new equipment.

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Posted by jeffhergert on Sunday, May 24, 2020 2:32 AM

BaltACD

Isn't it still required of a crew upon taking charge of a train after departure from the origin termina or after a crew change for a running air test to be made for the Engineer to judge the effectiveness of the train brakes?

 

Passenger yes, freight no.

As I recall, UP wants to use the wayside detectors to increase the mileage between inspections. I'd have to look but I think it was to double the mileage.  2000 miles for normal trains, 3000 miles for extended haul trains

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Posted by Lithonia Operator on Sunday, May 24, 2020 3:23 AM

OM, the print in the PDF was too small for me on this phone. I'll need to wait until I'm at my computer. Thanks.

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Posted by David1005 on Tuesday, May 26, 2020 12:20 PM

This probably comes from a paper published by the Western Canadian Air Brake Club and presented at the RSA show about ten years ago.  One of the large Canadian railroads wanted to find a way to test brakes on a coal train movement prior to winter without having to bring every car into the shop.  They thought that maybe checking wheel temperature at the bottom of a long grade when they were using air would provide them good data.  This test was done and all the cars with cold wheels were brought into the shop to determine why. 

Most of the paper has to do with the analysis of the problems found on cold wheel cars. They has a team of engineers that followed each car until the cause of the lack of braking was determined.  The most interesting outcome of this to me was the large number of cars that had defects that had existed for years, maybe since the car was built. These were both mechanical and pneumatic problems that were not detected by the existing static shop tests. 

My first though was that the use of piston travel or cylinder pressure to determine effective braking clearly has its limitations. As a result of this paper things would have to change. Requiring a golden shoe test on every new freight car, not just the first article, seemed like a place to start. Also closer monitoring of brake shoe changes on cars could identify cars with brake problems. My impression was that many brake defects exist for a very long time and conducting wheel heat tests, even once a year, would be effective. 

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Posted by traisessive1 on Tuesday, May 26, 2020 12:41 PM

BaltACD

Isn't it still required of a crew upon taking charge of a train after departure from the origin termina or after a crew change for a running air test to be made for the Engineer to judge the effectiveness of the train brakes?

 

 
Not in Canada, unless it's montain grade. 
 
The engineer or remote control operator has to do a running brake test on a transfer movement where a brake test wasn't done. 

10000 feet and no dynamics? Today is going to be a good day ... 

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Posted by SD70Dude on Tuesday, May 26, 2020 1:14 PM

traisessive1
BaltACD

Isn't it still required of a crew upon taking charge of a train after departure from the origin termina or after a crew change for a running air test to be made for the Engineer to judge the effectiveness of the train brakes?

Not in Canada, unless it's montain grade. 
 
The engineer or remote control operator has to do a running brake test on a transfer movement where a brake test wasn't done. 

I can think of a few places where it is physically impossible to do a running brake test first, as the grade extends right to the end of the track on those lines. 

It was probably CP who wanted to do the wheel temperature test first, as they have more coal trains and more grades on which air braking is needed.  CN is doing them as well now in certain locations.

Greetings from Alberta

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Posted by Overmod on Tuesday, May 26, 2020 1:56 PM

David1005
My impression was that many brake defects exist for a very long time and conducting wheel heat tests, even once a year, would be effective. 

This is an illustration why the types of test are complementary.

The inspection is to determine the physical state of the components (and find wear, cracks, missing pieces or seals,etc.)  This can be extended to checking valve function, hose and flash and integrity, network integrity and so forth on ECP systems.  As noted in the paper this says little about how effectively the brake equipment actually contributes to stopping a car or train.

The initial running brake test verified that all the connections are made properly and that the brakes apply and release as commanded.  Again, this does not and cannot tell effectively how well the individual brakes will actually take momentum off the train, only that the system works as commanded.

To measure how well the brakes actually work, you need periodic testing under full (and reasonably prolonged) braking conditions.  The Euclids among us might propose complex systems of strain gages in draft gears or thermocouples in brake shoes to determine braking force in the train, but simply by repurposing existing hot-bearing detectors you can assess every wheel (not just every axle) for heat, and from those data alone derive what is needed for brake-system effectiveness.

Note that it immediately follows, to me, that a "normal" brake test be conducted by reaching a reasonable safe speed before applying to a stop, then pulling past a proper detector array a short distance further.  This will assure that all the brakes have reasonably applied, pinpoint any equipment that may have been mistakenly cut out or malfunctioned, and potentially catch brakes that have stuck or caught... as well as the odd handbrake left partly applied.  I would then follow this with a second detection several miles downrange, the two sets of temperature then being directly proportional within a known time with reasonably predictable weather and other effects.  Nothing more complicated than one of the existing AI/ES systems is needed to track and analyze the resulting data without 'human intervention', and the result can be communicated to the crew referenced to the consist (so they know, for instance, that the 35th and 90th cars have hotter wheels, and that the whole block of grain cars from 10th to 30th positions are not doing their share of braking...)

Note also that, in keeping with the advantage of using train motion as the 'scan' for detection, a proper machine-vision system can look at the shoe gaps of the departing train and verify that all the beams and shoes have physically released... on both sides.  In my opinion this might in many cases save the crew from having to walk the train to confirm release, while providing a visual and sensor-fused record at the time.

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Posted by Juniata Man on Tuesday, May 26, 2020 3:24 PM

A question I have involves how ATBE adjusts for lighter cars that have load/empty sensors.  

Before I retired, a significant portion of our fleet was aluminum sparger cars with load/empty sensors.  When a car was empty, the sensor would detect that and reduce the braking force on the car.

If ATBE measures heat, an empty car with a properly functioning load/empty sensor would not generate as much heat during a brake application as would occur when the car was fully loaded.  How does ATBE adjust for this without automatically flagging every such car for a closer inspection?

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Posted by Overmod on Tuesday, May 26, 2020 4:37 PM

Juniata Man

A question I have involves how ATBE adjusts for lighter cars that have load/empty sensors ... If ATBE measures heat, an empty car with a properly functioning load/empty sensor would not generate as much heat during a brake application as would occur when the car was fully loaded.  How does ATBE adjust for this without automatically flagging every such car for a closer inspection?


Remember that ATBE only 'senses' wheel temp at the point of inspection, but is hooked into the 'rest' of the car-management system.  Since that system can tell (by car or UMLER information) that the car has load-sensing, it can determine that the braking effort is in the correct range.

Note that a good WILD detector may be able to read empty vs. loaded dynamics, and add in the information to help tell if the load sensor is working appropriately.

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Posted by Juniata Man on Tuesday, May 26, 2020 6:27 PM

Makes sense; thanks Overmod!

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Posted by SD70Dude on Tuesday, May 26, 2020 6:39 PM

BigJim
Overmod

Keep dreaming! They will find a way to cut someone's job, just you watch! I've watched it happen for over forty years!

I agree, though I do not have nearly that amount of seniority.

The railroads could use this to do all the great things that Overmod talks about, the technology exists.  But they won't.  This is all about $$$, and in CP's case, appeasing the regulator in the aftermath of the fatal Field Hill runaway. 

I will agree that No. 1 air tests have been a joke for years, the Carmen around here zip down each track in a ATV, which does not allow for a proper inspection. 

Greetings from Alberta

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Posted by Overmod on Tuesday, May 26, 2020 7:04 PM

SD70Dude
I will agree that No. 1 air tests have been a joke for years, the Carmen around here zip down each track in a ATV, which does not allow for a proper inspection.

Now I'm tempted, sorely tempted to note that an answer to this quandary is to have Transport Canada or whatever mandate that video of all brake testing be taken (as confirmation the test was done) and then give each merry carman on his ATV a steadicam-enabled video device ... which can actually be panned, tilted, and zoomed by remote control ... as he zips down and back.  He's happy, his union's happy, TC will be happy, Hilal is not out the price of a drone and pilot... and the job is no longer a joke.  (Especially if the carman zips down one side, bumps across, and zips up the other side.)

At any time if something strange is detected the carman can stop his little chariot of fire, and go over and inspect it firsthand; in other words he is actually there to do his job, with a full set of tools and test equipment bobbing along with him, when his skills are needed, but he is not wasted on the more routine parts of the job where dumb, fast, literal capital does better.

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Posted by tree68 on Tuesday, May 26, 2020 9:12 PM

I had a friend (an employee of a Class 1) get challenged by an FRA inspector after doing a "class one brake test" because there was only one set of tracks around the train in the snow...

So much for a set on one side and a release on the other...

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Posted by jeffhergert on Thursday, May 28, 2020 8:45 AM

You don't have to observe a set and release on both sides. (Except for some cars that have the brake cylinder in a position that it can't be viewed from both sides.) 

You do have to do a safety inspection on both sides. That's checking for possible defects, besides the brake system, that could cause problems.

Jeff

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Posted by Overmod on Thursday, May 28, 2020 9:08 AM

jeffhergert
You don't have to observe a set and release on both sides.

If I remember correctly, and it would have been dim originally and a long time since then, this was one of the arguments against truck-mounted wheel cylinders for freight cars.  When your consist is largely foundation-braked with beams, even clasp-braking is highly unlikely to stick on one side and not the other if it has passed a car inspector's static check -- one principal reason for floating brake-beams in the first place being that they inherently equalize shoe application to both sides on more than a very slight set.

Note that the first ATBE can figure out if there is any asymmetrical brake heating, perhaps another argument for using it shortly after a 'running brake test' from sufficient starting speed to give adequate 'infrared SNR'...

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