It will be months, 18-24 perhaps, before the National Transportation Safety Board (NTSB) releases its final report on the Norfolk Southern (NS) train derailment in East Palestine, Ohio. One should not try to crystal ball their findings and recommendations, but one thing in particular in its Preliminary Report gives rise to thoughtful consideration.
The temperature of one wheel bearing on the 23rd car in the train, which eventually failed, was reported, as follows:
“At MP 79.9, the suspect bearing from the 23rd car had a recorded temperature of 38°F above ambient temperature. When train 32N passed the next HBD, at MP 69.01, the bearing’s recorded temperature was 103°F above ambient. The third HBD, at MP 49.81, recorded the suspect bearing’s temperature at 253°F above ambient.”
I’m no expert in such matters. I don’t know if 38°F above ambient temperature has significance to warrant attention. However, just ten miles later, when the train passed the HBD at MP 69.01, the temperature of that same bearing had already risen 65°F.
That, in my mind, raises some important questions. The report also states that NS has established the following HBD alarm thresholds (above ambient temperature) and criteria for bearings:
- Between 170°F and 200°F, warm bearing (non-critical); stop and inspect.
- A difference between bearings on the same axle greater than or equal to 115°F (noncritical); stop and inspect.
- Greater than 200°F (critical); set out railcar.
My understanding, from the NTSB report and media coverage, is that all railroads can establish their own standards for programming HBD equipment and setting standards for triggering defect messages to train operating crews and instructions on how they should react. This triggers, in my mind, three questions:
- When trains past one HBD, that identifies X° temperature increase in one wheel bearing, out of perhaps 400 or more, and the temperature of the same bearing has risen Y°, at the next HBD, only ten miles later, should that not be cause to stop the train and conduct an inspection?
- Is the 170° threshold set by NS reasonable to insure safe train operations?
- Should the potential defect threshold be lower and governed by a regulation, and should it include a provision to require a train inspection when the temperature of a wheel bearing rises Z° between two HBDs in close proximity to each other?
In the coming months, trains will continue to operate under existing regulatory constraints that do not include things such as:
- Train size and configuration.
- The amount and type of hazardous materials being carried in mixed freight trains that would require compliance with existing hazmat train operating restrictions.
Additional HBDs may not be quickly added to railroad systems, which means railroads will have to make some important decisions on train movement and inspection rules, governed by HBDs and other equipment detectors. Will they, and will those decisions and actions be sufficient to ensure the safety of communities, across America, which they operate trains through?
The FRA has issued Safety Advisory 2023-01; Evaluation of Policies and Procedures Related to the Use and Maintenance of Hot Bearing Wayside Detectors (download below), “to make recommendations to enhance the mechanical reliability of rolling stock and the safety of railroad operations. This Safety Advisory recommends that railroads: evaluate the thresholds for inspections based on hot bearing detector (HBD) data; consider the use of real-time trend analyses of HBD data as a criterion for inspection; ensure the proper training and qualification of personnel responsible for the calibration, inspection, and maintenance of HBDs; ensure proper inspection of rolling stock with HBD alerts; and improve the safety culture of their organization, particularly as it pertains to operational decisions based on HBD data.”
The sooner the railroads and the Association of American Railroads (AAR) answer these questions will say a whole lot about their true commitment to public and employee safety.
Editor’s Note: Railway Age obtained the following 2022 statistics for Norfolk Southern on HBD readings and resulting actions:
- 2.2 billion: number of bearing temperature readings sent to NS headquarters in 2022.
- 618: number of times a hotbox detector triggers a train crew to stop the train.
- 353: number of times the issue was resolved and train proceeded.
- 181: number of times equipment was damaged and the issue was resolved.
- 84: number of times an overheated bearing was discovered and the car was removed from the train.
- 876: number of times trending analysis at the wayside detector help desk stopped a train before an alarm went off.
- 158: number of times a car was removed from the train due to trending analysis.
- 308: number of times a car was inspected and no issue was discovered.
- 14: average number of miles between hotbox detectors
So, in 2022, NS removed 242 cars from trains due to roller bearing heat problems. Divide that number by 2.2 billion temperature readings (every wheelset on every train that operated on the entire NS system in 2022), and you get 0.0000011. That makes the odds of an East Palestine-type derailment (one caused by a roller bearing failure) literally “one in a million.” But it happened. “Stuff happens,” unfortunately, despite everyone’s best efforts to operate safely, supported by technology. In my opinion, the above numbers, though they may mean little or nothing to the people of East Palestine, point to a safe railroad. — William C. Vantuono
William C. Keppen Jr., a retired BLET (Brotherhood of Locomotive Engineers and Trainmen) Vice President and third-generation locomotive engineer at BNSF and predecessors Chicago, Burlington & Quincy and Burlington Northern, is an independent transportation advocate with experience in fatigue countermeasures programs. A railroad industry veteran of almost 50 years, Keppen provides safety analyses for Confidential Close Call Reporting System (C3RS) programs in freight, commuter, and light rail transportation. Keppen was Project Coordinator for BNSF’s Fatigue Countermeasures Program, and former BLE General Chairman for the BN Northlines GCA. “I started working on human-factor-caused train accidents in 1980,” he says. “It has been a struggle. I would like to think I have made a difference, but there are still far to many human-factor-caused train ‘accidents,’ which I prefer to refer to as ‘preventable incidents.’”