I seem to recall reading that a ‘rail-enthusiast photographer’ had spotted a smoking car coming off Donner Summit but, of course, had no method of alerting anyone. By the time the car(s) got into Roseville Yard the conflagration was already well advanced. As I recall it was overheated brakes that set the wood flooring on fire.
Cheers, Ed
A means of continuously monitoring the bearing would be much better than any wayside detector. The acoustic emissions would normally start showing up some time before the bearing failed.
Balt did answer the question in that the “proprietary data” is covered by an NDA or equivalent. Getting the thresholds right can be a competitive advantage.
With half a million or more cars in transit around the country on the multiplicity of carriers - how are your continuously sensoring cars reporting the incipent failure and to whom?
One answer: an on-car processor reads data from the eight bearings ( and reflected shock from the wheels), stores and holds samples for comparison, and runs a small RTOS expert system looking at changes in waveform and intensity.
Some of these samples are downloaded at each wayside location, where they can be further processed and analyzed as desired. The information can be reasonably summarized in comparatively little bandwidth and kept in data structures in a ‘digital twin’ of the car maintained in the cloud. Since most of the criticality of data is only there when the car is moving, the updates are timely every few miles, and the forwarding and formatting does not imply excessively great bandwidth.
For emergency critical detection, as in unanticipated spalling of journal, roller, or race, or a broken wheel or axle, the car would be equipped with some emergency means of radio transmission, perhaps like a small ELT. This would transmit a warning detectable to PTC on the train, and to any part of the PTC ‘fabric’ connected to the train – and it would give customized and accurate advice for the ‘safest’ actions to stop the car for its position in the train, loaded state, proximity to PIH, etc.
As WH pointed out, while the recording/analysis of the acoustic emission sensors would be done continuously, the data would usually be transmitted in bursts. Ideally the car computer would only have to report “all good” when nothing was detected. In case an emission was detected, the software would analyze the signal(s) to report the level of the problem as is done WILD sensors. Courses of action would run from getting the bearing checked when convenient to halting the train and setting the car out. The main application for these sensors is on cars carrying hazmat, where a derailment would have severe consequences.
Aren’t these FRA standards?
Not that I’m aware of.
Acoustic emissions detectors have been in use for years in stationary applications (e.g. process critical pump), where power and communications are available. The idea is to detect signs of bearing failure early enough so that the bearing can be replaced in a scheduled downtime. A freight car truck is a much more hostile environment than a plant floor and getting a source of reliable power would be a challenge. There’s also an issue of filtering out noise from the wheelsets rolling on track.
I would think there would be consistent, national standards for flat wheel detection, not every railroad has own, classified standard.
Wouldn’t all cars need such sensors to be of any real worth? I don’t have statistics, but I bet hazmat loads get caught up more often in derailments initially caused by other cars or other reasons, i.e., broken rails, etc.
Jeff
We’ve had a bit of a disconnect. My answer was based on the assumption that you were referring to bearing failure detection, which is a very different issue than flat wheel detection.
Added commentary: From what I gather from a perhaps limited knowledge of track maintenance, a flat wheel will be a significant track maintenance problem long before it becomes a track safety problem.
Back in the early 90’s, the lab space I was working in was about 70’ from the AT&SF Surf line. When the Coaster service started, we could tell the difference between a Coaster train and an Amtrak train as the latter almost invariably had at least one wheel with a flat spot, while the Coaster rarely had any flat wheels.
Jeff, good question. It may be necessary to require Key Trains to have most or all cars equipped with bearing monitors. I was assuming that having the burnt off axle under one of the hazmat cars exacerbated the damage to the tank cars.
I do remember reading about some railroads wanting to handle spent nuclear fuel cars in dedicated trains where the consequences of an accident would be substantially less than East Palestine - the spent fuel casks were designed to take an incredible amount of punishment.
Rule of thumb is if you can hear the flat wheel from seven cars away, it probably needs attention…
And 2 cars distant?
Pretty normal.