FRA advisory: High-impact wheels damage rails, track structures

The Federal Railroad Administration has issued a safety advisory recommending railroads utilize wheel impact load detectors (WILD) to identify and replace high-impact rail-car wheels that could cause significant damage to rail and supporting track structures.

The FRA's preliminary investigation of a recent train derailment in Gothenburg, Nebraska, indicates that high-impact wheels damaged the rail the train was operating over and caused the derailment, FRA officials said in the advisory. Current industry practices for using WILDs to identify and replace high-impact wheels could help prevent such incidents in the future, according to the advisory, which the FRA published yesterday in the Federal Register.

In 2015, the FRA issued a safety advisory that recommended the use of WILDs. FRA recommended railroads continue to install and maintain WILDs along certain routes and monitor their measurements to determine when to replace wheels. In the 2015 advisory, FRA also recommended that railroads lower the impact threshold for action to replace the wheels on any car in a high-hazard flammable train.

In this latest advisory, the FRA recommends that, in light of the Gothenburg accident, railroads and contractors continue to use WILDs to help identify and replace high-impact wheels according to railroad current industry practices. Wheels with a WILD measurement greater than 80 KIPs should be replaced when in a repair shop, and wheels with a measurement greater than 90 KIPs should be replaced when found in any other location in service. 

The FRA also recommended that railroads review procedures for identifying dynamic ratios to help predict high-impact wheels when cars are loaded. A dynamic ratio is the ratio of a WILD measurement of a loaded rail car compared to when it is empty. The peak impact is the highest WILD measurement recorded. The impact measurement varies during operation due to the changing operating environment, including changes in speed.

Wheels should be replaced when an empty rail car with a dynamic ratio of 5 or higher has a preceding peak impact greater than 100 KIPs, according to the FRA.

The FRA is urging railroads and contractors to review the new advisory with employees.