Overheating wheel detected too late to stop Ohio train before it derailed

The engineer at the controls of the Norfolk Southern train that derailed in Ohio tried to stop the train following a warning about an overheating wheel, but by that time several cars had already come off the tracks, according to a preliminary report released Thursday by federal investigators.

According to the report, before it derailed, the train passed three detectors intended to alert train crew to physical problems, including overheating wheels. Though the train detectors showed one of the wheels was steadily getting hotter, it did not reach a temperature Norfolk Southern considered critical until it passed the third detector and alerted, as outlined by the National Transportation Safety Board.

When the train passed that last detector, the detector “transmitted a critical audible alarm message instructing the crew to slow and stop the train to inspect a hot axle,” the report said.

By then, the engineer was already trying to slow the train. Upon hearing the alarm, the engineer increased the application of the brakes, and then automatic emergency brakes initiated, bringing the train to a stop.

When it stopped, the crew “observed fire and smoke and notified the Cleveland East dispatcher of a possible derailment,” the report said.

Thirty-eight cars derailed and 12 more were damaged in the ensuing fire.

NTSB is continuing to investigate the wheelset and bearing, the design of the tank cars themselves, the accident response, including the venting and burning of the vinyl chloride, railcar design and maintenance procedures and practices, Norfolk Southern’s use of wayside defect detectors, and Norfolk Southern’s railcar inspection practices.

NTSB will brief reporters Thursday afternoon about the report.