Showing posts with label Bearings and Hot Boxes. Show all posts
Showing posts with label Bearings and Hot Boxes. Show all posts

Monday, October 23, 2023

East Palestine Derailment: It's the wheel bearings stupid!

What was the exact cause of the East Palestine Derailment?  Well, you may know that a railcar in Norfolk Southern's Train 32N had a wheel fall off and derail the train, and spilled hazardous chemicals, like vinyl chloride. It's important to know facts, as some attorneys, like Ohio's AG, David Yost, seem to believe that there's enough negligence when it comes to "holding Norfolk Southern accountable" to win in a court of law where FACTS of THIS derailment (not others) matters.  Well, Yost is probably, as of this date, October 23, 2023, going to fall short when it comes to duty of care

A slow, flaming end for Railcar 23's wheel.  These wayside defect detection devices, or hot bearing detectors (HBDs), send a real time audible alarm to the crew to stop and inspect the train when detected temperatures exceed a set limit.  HBDs can and do give false and wrong readings, and there is better technology out there. 

There are currently no federal laws that mandate how far apart these defectors are to be placed and no mandated temperature limits to be reached before action is taken. The railroads set their own standards. Norfolk Southern (NS) has equipped its rail networks with systems of temperature detection devices that measure the temperatures of the wheel bearings of passing trains. These HBDs along Norfolk Southern's tracks were working as intended and not "broke," "stuck", or "turned off" or whatever, on February 3rd. 

The  2023 Railway Safety Act addresses the perfect storm of incidents that collectively lead to the the East Palestine Derailment.  It's a perfect storm of the failed wheel bearing, it's burning of grease, flames, then the total failure when the crew applied the brakes when it was hot enough to trigger Norfolk Southern's HBCs. and this is not any kind of negligence by Norfolk Southern. 

 Train 32N passed three of the detectors in a 30 mile span (average of one per 10 miles) near East Palestine, and it was only when Train 32N passed the third detector that the temperature 253F was detected, well over the 200F limit set by Norfolk Southern, which would require the crew to remove and set out the defective railcar. The distance between HBDs and the temperature that would trigger the alarm for overheated bearing are addressed in the 2023 Railway Safety Act. 

The HBDs errors and bearing failures.  The flaming failure of wheel bearings in Railcar 23 is the reason and cause of the East Palestine derailment. People who witnessed Railcar 23's troubles called 911 (and not a railroad emergency number).  According to Jim Scott, a railroad consultant with five decades of experience, was the eventual result of the grease of the axel burning off which lead to Railcar 23's flaming wheel as its moving on the tracks. When the train crew began the process of stopping the train, the wheel fell off and began the derailment: 

"At that point, grease is burning. That's what we believe. All the lubrication has gone from that roller bearing and that's why it's heating up, It's failing. And when it's gone, it's gone. It will eventually just fall off" Jim Scott, railroad consultant (1).  

Then, there is the question as to why the HBDs, especially the first two of the three, did not "properly detect" the "correct temperature" of Railcar 23's flaming wheel.  There is one who believes that the crew received an alarm, but the dispatcher "told the crew to keep going" (2).  However, HBDs are known to give faulty readings, according to a study on HBDs: 

"Generally, wayside HBDs tend to underestimate the temperatures of bearings in field service operation, which is not surprising given the simple one-point calibration procedure that is used to calibrate these devices. Underpredicted temperatures can have disastrous consequences, especially if a defective bearing goes undetected by a wayside HBD" (Tarawneh 2020: 282). 

Train 32N had 594 axles and the journal box could (box with the bearings), and did, fail at anytime during the trip down the Fort Wayne Mainline.  In fact - Federal Railroad Administration (FRA) has said that between 2010 to 2018, there were 124 incidents of railcars with bad bearings, resulting in 117 derailments.  The US Department of Transportation has credited HBDs with reducing accidents by over 80% since 1980. 

According to the FRA, a wheel bearing can burn off in about 1 to 3 minutes. National Transportation Safety Board Chairwoman Jennifer Homendy commented during a briefing that “roller bearings fail, but it’s absolutely critical for problems to be identified and addressed early, so these aren’t run until failure." 

Experts argue that relying on HBDs alone to prevent accidents can be "crapshoot" according to Tarawneh, as HBDs alone are faulty and unreliable. Experts like Tarawneh believe temperature is not the best primary way to measure the condition of a rotating object, but a good secondary way.  So, Tarawneh thinks it does not matter how close we place our HBDs. Placing HBDs 10, 15, 20 miles apart if not going to matter. What the experts and researchers believe is that acoustics, listening devices, should also be used...and that sensors should be on the railcar itself.:

"[T]emperature alone is not a good indicator of bearing health. Based on that, the authors have been developing a system that utilizes temperature, load, and vibration sensors mounted directly on the bearing adapter for continuous monitoring of bearing condition. Laboratory testing validated by field testing have shown that this system can reliably detect the onset of defect development within a bearing and track its deterioration with service operation. The authors believe that systems like these will shape the future of bearing condition monitoring" (Tarawneh 2020: 282).

 Where's Norfolk Southern's fault with Railcar 23? The  2023 Railway Safety Act addresses the perfect storm of incidents that collectively lead to the the East Palestine Derailment.  Railcar 23's demise was a perfect storm of the failed wheel bearing, it's burning of grease, flames, then the total failure when the crew applied the brakes when the bearing were hot enough to trigger the third HBD alarm. The railroads set their own standards and Norfolk Southern's standard is not illegal, as stated, there is currently NO federal law that regulates HBDs use.

According to the NTSB, Norfolk Southern's HBDs were operational and working as intended during the night of February 3rd.   

The experts say that the HBDs in use by the railroads have a tendency toward faults and are unreliable. The reason why this derailment got so much attention is the involvement of hazardous chemicals. The  FRA has said that railcar wheel bearings can fail and burn out in 1 to 3 minutes. Some believe that the reason for the flaming on Railcar 23's wheels was from the grease burning itself out, where the end would come when the wheel fell apart. 

To add here, the experts also say that adequate inspection of sealed wheel bearings would mean ripping them apart, but that's for another post. 

The perfect storm of events that lead to Railcar 23's demise appeared to not be some outright negligence by Norfolk Southern. Despite sometimes being faulty, HBDs have reduced accidents, and the Norfolk Southern HBDs were working, according to the NTSB report. The crew was not at fault, wheel bearings can fail at any time, HBD's give faulty readings, HBDs are unreliable, the temperature is not hot enough yet to stop the train, grease burns in failing wheel bearings, and a failed wheel bearing set leads to the wheel eventually falling off, causing derailment...starting a chain reaction where the other railcars behind Railcar 23 also derail, some are tank cars carrying hazardous materials.  

Nowhere in this perfect storm of wheel bearing failure could we see the tornado coming. 


1. qtd. in Bill Stephens, 6 March 2023. 

2.  In Pennsylvania Senate hearing on the derailment,  Bob Comer, a railroad crossing accident investigator,  accused Norfolk Southern dispatchers of "ignoring temperature alarms" as Railcar 23 passed HBDs with a flaming wheel. 


Anderson, James.  "East Palestine Derailment: It’s in the Bearings. Overheated bearings are a common cause of train derailments." March 13th, 2023. 

Constantine Tarawneh, et al. (2020) " An investigation into wayside hot-box detector efficacy and optimization," International Journal of Rail Transportation. Accessed online: October 4th, 2023.

Levin, Alan.  "Ohio Train Crash Puts Spotlight on Heat Sensors Panned as Unreliable." American Journal of Transportation. March 2rd, 2023. 

NTSB  Norfolk Southern Railway Train Derailment with Subsequent Hazardous Material Release and Fires. February 3, 2023.

Stephens, Bill. "Wheel bearing expert: To prevent derailments, railroads should equip freight cars with March 6, 2023.  

Saenz, Marisa. "3News Investigates: Railway experts weigh in on axle inspection after East Palestine train derailment." WKYC.  February 24, 2023. 

Sullivan, Becky. "Here's the most thorough explanation yet for the train derailment in East Palestine." NPR. February 23, 2023.

Wallace, Greg and Laura Ly.  "NTSB says videos of Ohio train derailment include one showing wheel bearing in ‘final stage of overheat failure.' " CNN. February 21, 2023.  

Winsor, Morgan and Meredith Deliso.  Ohio train derailment: NTSB chair issues 'plea to those spreading misinformation'. ABC News. February 18, 2023

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