WASHINGTON – The Federal Railroad Administration has issued a safety advisory calling on railroads to use wheel impact load detectors to properly identify and replace freight car wheels that could significantly damage track and lead to derailments.
The advisory was issued yesterday in response to the Feb. 21 derailment of a Union Pacific coal train on the Overland Route in Gothenburg, Neb. Thirty of the train’s cars derailed – including some that had been operating for several months after wheel impact load detector measurements had flagged their high-impact wheels.
“FRA’s preliminary investigation indicates the derailment was likely caused by high-impact wheels breaking a track joint bar. Records from FRA’s investigation show one of the freight cars had a WILD measurement of 130.6 KIPs when it operated over the track joint bar that was found broken,” the advisory says. “Records also show this freight car continued to operate for several months prior to the derailment after its high-impact wheels were identified by WILDs. WILD measurements showed high-impact wheels in November and December 2022, and again in January 2023. During its investigation, FRA also identified eight other freight cars in the derailed train with high-impact wheels.”
Wheels with a WILD measurement of greater than 80 KIPs should be replaced when in a shop, while those with a measurement greater than 90 KIPs should be replaced when found in service, FRA said.
The FRA also said railroads should review dynamic ratios that compare a car’s WILD measurements when loaded and when empty.
“Wheels should be replaced when an empty railcar with a dynamic ratio of 5 or higher has a preceding peak impact greater than 100 KIPs. Replacement at such time will reduce or eliminate further damage to the freight car’s wheels, rails, and track structures,” FRA said.
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