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Citizen hotbox detection? Is it possible?

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Posted by tree68 on Friday, July 12, 2024 6:29 PM

Overmod
The problem with monitoring the endcap is that the detector only monitors the temperature rise at the outer face, when the temperature close to the inner bearing in the axle metal may have reached dangerous elevation.

I mention the end cap only as a location for the transducer, which would be connected to sensors within the bearing.

This would allow a trackside transducer to receive data, as opposed to something under the train.

LarryWhistling
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Posted by dpeltier on Friday, July 12, 2024 7:26 PM

charlie hebdo

What would be the cost of EIGHT of 'your' detectors per car? Multiplied by cars in use nationwide.

What would be the cost of another East Palestine or worse?

$1.7B is the cost Norfolk Southern put on their balance sheet last I heard. This includes government fines and a class-action lawsuit settlement, as well as ongoing environmental and health monitoring. We don't know what the actual damages are and won't know for some time. My personal guess is that, had they been willing to be dragged through the mud of public opinion and forced everyone to justify their damage claims, they could have cut hundreds of millions off that settlement.

For how this compares to the cost of equipping the fleet with on-board sensors, see my previous post:

https://cs.trains.com/trn/f/111/t/294832.aspx?page=2#3442527

You're welcome to check my math. I estimated the ANNUALIZED cost of rare mega-events like East Palestine at $10M / year (for bearing failure incidents only), which given the final figure of $1.7B is probably too low. So I'll make some revisions.

Let's say that $1.7B event happens every 40 years (since I'm fairly certain there hasn't been anything comparable in the last 40 years), the annualized cost of that is $43M / year. Based on FRA data from 2018 to 2022, I estimated "typical" damages from mainline bearing failure at $20M / year, so the total potential savings from improved bearing-failure detection is $63M / year. If on-board sensors can prevent 80% of those incidents, they would be worth $50M per year.

Following the same calculations as my previous post, a sensor system that lasted for 20 years, prevented 80% of all bearing-related derailments that are happening out there today, and created 0 false positives, could have a lifecycle cost of about $125 per bearing and still break even. That's similar to the cost of replacing a tire pressure sensor in your car, and those don't last anywhere close to 20 years.

That's just the sensor! Equipping each car with the equipment to read the sensors and report it to wayside equipment or the locomotive would add considerably more cost. But even if the car has some sort of a future ECP braking system that provided a ready-made com link to each car, on-board wheel bearing sensors would not be cost effective.

And with East Palestine likely to result in mandated improvements to wayside bearing sensors, the cost-effectiveness of onboard sensors will further decrease.

Dan

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Posted by Overmod on Friday, July 12, 2024 8:11 PM

tree68
I mention the end cap only as a location for the transducer, which would be connected to sensors within the bearing. This would allow a trackside transducer to receive data, as opposed to something under the train.

Tree, the 'transducer' IS one of the sensors; it is a device that converts a signal from one form (e.g. acoustic) to a waveform that can then be digitized, stored, transmitted and analyzed, etc.

The thing that does the bidirectional transmission is a transceiver, even if it uses polyspectral light instead of radio.  Still makes better sense to put it on the sideframe instead of the rotating endcap, as it doesn't matter if anything but the specific staring IR sensor is optimized via 'machine vision' to look for endcaps and their characteristics.

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Posted by tree68 on Friday, July 12, 2024 9:05 PM

Overmod
Tree, the 'transducer' IS one of the sensors; it is a device that converts a signal from one form (e.g. acoustic) to a waveform that can then be digitized, stored, transmitted and analyzed, etc.

I'll buy that.  Again, I was thinking of two things - the operation of the low air sensor on your road vehicle (almost always triggered by the first cold snap of the season), and the idea of having the RFID as part of the axle/wheel assembly, as opposed to having to connect to the car in some manner.  

LarryWhistling
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Posted by jeffhergert on Friday, July 12, 2024 9:39 PM

SD60MAC9500

 

 
jeffhergert

 

From the explanation given on another forum, I think more acoustic detectors are what's needed. They can find a bearing that's beginning to fail before there's any heat.

Jeff

 

 

 

The problem with ABD's is they give off the same, if not more false positive's than HBD's. Train 32N that derailed in EP, OH passed 3 ABD's, giving off no warning. The other issue is that a bad bearing can also be silent. Onboard bearing detection (located on the bearing adapter) would detect vibrations. In fact a company called HUM is trialing this tech as we speak.

https://www.humindustrial.com/products

 

What was explained elsewhere is that a bearing starting to fail start making a sound that is not heard by the human ear.  (Maybe we can station K9 detectors every do often.*)  This begins 100 or 150 miles before the bearing starts really getting bad.

* I seem to recall the experimentation of using dogs to "sniff" out bad bearings when doing inspections at yards on inbound trains.  This may have been back when there were more plain bearings in use.

Today, after my last post last night, we had to stop so the conductor could go back and check a bearing getting hot.  It didn't set off the detector, the bearing desk had the dispatcher stop us and relay the car and axle needing inspection. 

The condr went back 38 auto racks, checked the indicated axle and 20 axles each side and the same on the other side of the train.  He found nothing.  The bearing desk, through the dispatcher, allowed us to proceed at 30 mph to the next detector, about 6 miles away.

After clearing it, we were instructed the temperature was dropping.  The condr and I discussed if the bearing had been hot, which he didn't find, could it have cooled while he made his way back?  It probably took 20 to 25 minutes to get back to it.  They said they would continue to monitor the car.

Jeff 

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Posted by Euclid on Monday, July 15, 2024 12:15 PM

Overmod

I think I have mentioned this before.  When an inner bearing starts to fail, the heat produced is transferred by conduction, outward from the outer race of the bearing and casing into the sideframe, and inward to the axle, thence in toward the wheel and out toward the end cap.  

I can see how that could be a problem.  You have heat of a failing bearing being produced inside of the bearing and transferring outward by conduction and radiation, through a variety of other structure of the truck, and into the car frame. On the way out, heat is lost by conduction and radiation from the heated railcar parts, at various rates, to the unheated air and railcar parts.
 
Then the wayside detector takes a reading only on the radiant component of this flow of escaping heat being transferred by a blend of radiation and conduction. 
 
There will also be background heat production from routine air braking that heats up all metal in the vicinity, including the bearing housings and components.  How in the world can you get a meaningful measure of bearing temperature with all of this background clutter?  Whoever thought this methodology would work?
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Posted by Overmod on Tuesday, July 16, 2024 7:24 AM

Euclid
There will also be background heat production from routine air braking that heats up all metal in the vicinity, including the bearing housings and components.  How in the world can you get a meaningful measure of bearing temperature with all of this background clutter?  Whoever thought this methodology would work?

This is actually easy even with the older 'spot' type of IR detector.  The usual reason for 'hot wheels' is some kind of sticking brake, and that usually gets reported right at the first detector out of the train's point of origin.  Remember that the lion's share of these wheelsets are in three-piece freight trucks, where a considerable arc of the wheel is exposed to 'lateral view'.  The sticking brakeshoe(s) heat the wheel from the tread in, and there is a considerable thermal mass in the rim and then a constrained volume through the plate to slow down heating by the time you get anywhere near the mass of the hub and then the axle fit.

Now you have a detector set up to record hot end caps.  Suppose the truck moves about 18" -- that detector is now pointing right at a piece of the wheelrim.  And if it is hot, either in active friction or because it's heatsoaked... BING!

Later mosaic or 'staring array' detectors actually produce a moving image in IR wavelengths, so you can distinguish a hot curved wheelrim from a hot cap or other bearing-related issue.  We had AI/ES almost half a century ago that could distinguish this even without sensor fusion.

The problem remains as it was observed at East Palestine: if all the visible fire and heat is out of the focus of the detector you're using, the observed heat rise at 'axle-end level' may not trend upward fast enough, or reach a high enough level, to give the 'right' warning in time... or permit wayside alerts or 'service desks' to get the right advice to give train crews.

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Posted by tree68 on Tuesday, July 16, 2024 12:36 PM

Overmod
Now you have a detector set up to record hot end caps.  Suppose the truck moves about 18" -- that detector is now pointing right at a piece of the wheelrim.  And if it is hot, either in active friction or because it's heatsoaked... BING!

As I envision it, you wouldn't be looking for hot end caps - you'd be reading RFID-type information from a AEI-type transducer in/on the end cap.  That data would come from internal sensors - measuring the inside race temperature.   Blend this with pure IR readings from the rest of the wheelset to come up with a picture of what's going on. 

LarryWhistling
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Posted by BaltACD on Tuesday, July 16, 2024 1:15 PM

I don't think any of us retirees are qualified to know what the present day 21st Century Defect Detector actually is.  Technology changes - rapidly.  What technology was when we retired, in my case 7 years ago, leave a wide gulf on what was in place then and what is in place now.

Never too old to have a happy childhood!

              

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Posted by jeffhergert on Tuesday, July 16, 2024 7:16 PM

Until relatively recently, you didn't hear off a bearing burning (figuratively speaking) very often. Even now it doesn't happen a lot. Still,  it seems it's happening more than it did.

It seems, anecdotally - as all experiences are, that the rise in number seems to corespond with the cutting off of mechanical staff and the rise in the use of hot bearing desks. Kind of like instead of good mechanical inspections they'll gamble that the detectors will catch a bearing in the early stages of failing, before it causes headlines in the news.

One man who was once a Carman, said they used to inspect the inside seal of the roller bearing (where it's close to the wheel) with a tool they devised. If the seal was loose, the wheelset was changed out. The loose seal would start leaking grease and eventually fail. He said they found about 8 cars a day at the yard he worked at that needed the change out.

Inspections like that would take a bit more time and require actually walking instead of driving a set and/or release. Time is something the remaining forces don't really have.  They're under the gun to get things done ad quick as possible, too.

Jeff

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Posted by BaltACD on Tuesday, July 16, 2024 8:02 PM

jeffhergert
Until relatively recently, you didn't hear off a bearing burning (figuratively speaking) very often. Even now it doesn't happen a lot. Still,  it seems it's happening more than it did.

It seems, anecdotally - as all experiences are, that the rise in number seems to corespond with the cutting off of mechanical staff and the rise in the use of hot bearing desks. Kind of like instead of good mechanical inspections they'll gamble that the detectors will catch a bearing in the early stages of failing, before it causes headlines in the news.

One man who was once a Carman, said they used to inspect the inside seal of the roller bearing (where it's close to the wheel) with a tool they devised. If the seal was loose, the wheelset was changed out. The loose seal would start leaking grease and eventually fail. He said they found about 8 cars a day at the yard he worked at that needed the change out.

Inspections like that would take a bit more time and require actually walking instead of driving a set and/or release. Time is something the remaining forces don't really have.  They're under the gun to get things done ad quick as possible, too.

Jeff

Simple Fix - Inspection Pit with a carman to visually look at the seals and other under car potential defects - Bad item is seen and carman pushes a button that will Paint an identity mark on the failed axle seal axle and afix a Shop Ticket.  Wasn't this a accepted procedure half a century or so in the past?

In the 21st Century an automated camera system with AI could do the function minus the manpower.

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Posted by zugmann on Wednesday, July 17, 2024 11:25 AM

jeffhergert
Inspections like that would take a bit more time and require actually walking instead of driving a set and/or release. Time is something the remaining forces don't really have.  They're under the gun to get things done ad quick as possible, too.

You'd also have to inpect cars, and not just block swap them and let them ride on the old airslips. 

But that goes against psr....

It's been fun.  But it isn't much fun anymore.   Signing off for now. 


  

The opinions expressed here represent my own and not those of my employer, any other railroad, company, or person.t fun any

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