NTSB derailment investigation renews concerns about detectors, tank cars and Norfolk Southern

The National Transportation Safety Board’s daylong hearing on what caused the disastrous East Palestine train derailment near the Ohio-Pennsylvania border last year gave the community, railroads and policymakers plenty to think about.

The NTSB confirmed the crash was caused by an overheating bearing on one of the rail cars, and they detailed why officials were wrong to blow open five tank cars of vinyl chloride and burn the contents.

Here are some of the agency’s key findings from Tuesday’s hearing:

Trackside detectors

The detectors railroads use along their tracks to help spot overheating bearings, flat wheels and dangling equipment were a key focus of the NTSB investigation.

The Norfolk Southern train that derailed in East Palestine passed three so called “hot box detectors” just before the crash, but the train’s overheating bearing wasn’t caught in time even though surveillance footage showed a fire underneath the rail car as it passed through Salem, Ohio.

The detectors did notice the temperature increasing, but didn’t signal an alarm soon enough. NTSB investigators said the detector in Salem didn’t get an accurate temperature reading even though it showed the bearing was 103 degrees hotter than the outside temperature. That’s partly because it can take a while for the heat from a burning bearing to reach the outside of the axle where it can be measured.

<bsp-list-loadmore data-module="" class=«PageListStandardB» data-gtm-region=«RELATED COVERAGE» data-gtm-topic=«No Value» data-show-loadmore=«true» data-gtm-modulestyle=«List B»> <bsp-custom-headline custom-headline=«div»> RELATED COVERAGE </bsp-custom-headline> <bsp-custom-headline custom-headline=«div»> NTSB chair says Norfolk Southern interfered with derailment probe