@gabevistica
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Welcome Ken! Beaver County Library is hosting an event next month at CCBC that some of us are attending, hope to see you there! You should be able to find the forum thread if you search “LibraryCon”.
There’s also a couple other events happening sooner, but none so close to your neck of the woods
Welcome! Be sure to check out the Events and Meetups sections of the forum to see when things are happening!
I’ll have my crane MOC, which can drive around a bit (depending on the friction available from table coverings), and I’m hoping to have enough semi-reliable GBC modules to make a small loop but that’s a definite “maybe”.
(I have a reply here someplace that doesn’t want to show up, with links to the Events and Meetups sections of the forum, maybe that got it moderated or something… Anyway, welcome!)
I wasn’t blaming the sensor (faulty or otherwise), but I may look deeper now, so thank you for the info and also for the nudge back to the main topic. I look forward to seeing the lubricators and detectors in the future!
Thankfully it wasn’t THAT bad. Defect detectors are usually spaced every 10-20 miles along the tracks and log quite a bit of data about the trains that pass, but they send a necessarily-short audio report to the engineer over the radio (they’re busy driving, they can’t read a digital report on all 400+ axles in their train), typically their milepost location, “no defects” or “defect at axle N, stop the train”, and the total axle count of the train.
(As an aside, train cars are not fitted with individual sensors because trackside detectors usually do the job well enough and are a far lower maintenance burden than active electronics and power supplies on every car in a dozen or more national fleets (some cars aren’t owned by the railroads, but leasing companies).)
The train involved in East Palestine, OH passed numerous defect detectors as it approached the accident site, but the three closest to the accident are the relevant ones. The first registered a slightly high wheel bearing temperature, but nothing very abnormal (I’m not sure how different it was compared to other wheels, it was somewhat hotter than the air, but that seems reasonable for a moving wheel). The second detector 10 miles later registered a significantly higher temperature, but still not quite high enough to trigger any alarm, and there’s no system in place (that I know of) that would track trends for a given wheelset across different detectors to give short post-analysis reports to the crews that something is heating up rapidly even when it’s not yet critical.
When the train passed the third detector, 20 miles after the second, the bearing had reached a high enough temperature to trigger a severe alarm and the engineer began stopping the train almost immediately, but that takes a couple minutes when you’re slowing down several thousand tons of train that stretches a mile or more in length, and the wheelset failed catastrophically before the train came to a complete stop, causing the derailment (and throwing the whole train into an emergency stop when the brake hoses disconnected as a result).
Now, could NS higher-ups have decided to set the alarm thresholds across the whole railroad a bit higher than was prudent? Sure, that’s possible, false alarms would make lots of trains stop mid-line and clog up the system, so maybe they went a little far. But could ANYONE have told that train crew “ignore the hotbox, keep going”? No, there was no time or middleman passing along the defect report to say “this sounded an alarm, but keep going”, and no reasonable engineer would have listened to that anyway because, just as you said, the only way “keep going” ends is the wheelset melting (as we all saw when the train derailed). I’m not sure where this rumor came from but to be blunt, I think it’s rather ridiculous. They’re at fault, sure, but not that directly.
A video I watched not long after the accident (and just rewatched to make sure I was accurate) is https://youtu.be/uPno1IVTkFY from Practical Engineering, it explains things really well for folks who aren’t familiar with railroads (or this particular aspect of them).
