PITTSBURGH — The Norfolk Southern freight train that derailed in East Palestine, Ohio, on Feb. 3 had passed through three temperature sensors designed to alert problems like the hot bearing that eventually failed that day.
But the only sensor, called a hot box detector, that registered a sufficiently high temperature to sound the alarm was the one less than a mile from the accident site, according to preliminary findings from the National Transportation Safety Board, released Thursday.
Although at least two videos taken from security cameras in Salem, Ohio — 20 miles west of the derailment site — showed the train had one car that glowed from the bottom, the hot box detector at that site assessed the temperature of the fiery bearing on the rail car to be 103 degrees Fahrenheit above ambient temperature.
