An overheated wheel bearing is what caused the Feb. 3 derailment of a Norfolk Southern train carrying hazardous chemicals in East Palestine, Ohio—an incident that was “100 percent preventable,” according to National Transportation Safety Board (NTSB) Chair Jennifer Homendy.
“Every event we investigate is preventable,” Homendy noted at a Feb. 23, press conference in Washington. “Know that the NTSB has one goal, and that is safety and making sure this never happens again.”
According to the report, while the train was braking, it passed a wayside defect detector, also known as a hot bearing detector, which alerted the crew via an audible alarm message to slow down and inspect a hot axle. After the train had stopped, the crew noticed fire and smoke and notified the Cleveland East dispatcher that a derailment may have occurred.
Investigators also determined that the train passed three hot bearing detectors along its route before the alarm was triggered, with the wheel bearing steadily increasing in temperature along the way.
Under Norfolk Southern’s protocols, when a wheel bearing’s temperature reaches 170 degrees above ambient temperature, the crew is required to stop and inspect it. The crew is also instructed to inspect the situation if the temperature difference between the two wheel bearings on an axle is 115 degrees or greater. Meanwhile, a wheel bearing temperature of 200 degrees above ambient is considered “critical,” at which point the crew must disconnect the rail car.
On Feb. 3, the wheel bearing in question did not reach any of those benchmarks until after the train had passed the second detector, so the crew was not alerted until the wheel bearing had reached the critical heat of 253 degrees above ambient temperature, the report said.
As for whether additional hot bearing detectors along the train’s route could have prevented the derailment, Homendy said that is just one of the questions the NTSB will explore in its investigation.
Homendy also announced that the NTSB would hold a “rare” investigative field hearing to question invited witnesses about the incident. The goals of the hearing, she added, would be to inform the public, collect factual information, discuss possible solutions, and “build consensus for change.”
Further assuring reporters that the NTSB’s investigation would produce not only answers but results, Homendy stated: “There are [safety] recommendations we have consistently worked on for 50 years—positive train control is a great example. We don’t give up, and we won’t give up on this one.”
