FRA releases research reports on train length

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On Wednesday, the U.S. Department of Transportation’s Federal Railroad Administration (FRA) finalized three reports looking at the safety and performance of long trains.

The FRA said it recently sent the reports to the National Academy of Sciences (NAS) to inform an ongoing study mandated by Congress. The larger NAS study, part of the Bipartisan Infrastructure Law, looks at the impact of trains longer than 7,500 feet. FRA said its reports include findings from tests conducted on air brake racks and the air brake system behavior and performance. FRA also conducted tests on a moving train to better understand the dynamic performance of long trains, the agency said, and to collect data on train dynamics and brake system performance.

The agency said its research found that air brake systems mostly performed as expected when tested under ideal circumstances and in a controlled environment. However, the reports noted that the likelihood of unintended brake releases was higher with longer trains and that increased train lengths led to slightly slower brake response times, and that distributed power train configurations achieve better braking capability that only head-end power on long train operations. Additionally, testing found that when long trains climb a grade, certain sections of the train experience elevated buff forces and coupler forces. FRA researchers determined more testing is needed to identify potential safety gaps when operating long trains in non-ideal operation conditions.

“As the length of freight trains increases, the need and demand for accurate, actionable data on long trains – some of which can stretch up to three miles – has never been greater,” FRA Administrator Amit Bose said. “FRA is leading the push for more transparency and data in this area, and through our collaboration with stakeholders in labor and the rail industry, we are ensuring that freight rail operations can operate safely and efficiently without putting rail workers and communities in potentially harmful situations.”

FRA has previously expressed concern about train makeup and the complexities of operating longer trains. In April 2023, the agency issued a Safety Advisory to railroads after a series of derailments were found to be caused by improper train makeup. The agency also issued a Safety Advisory in May 2023 cautioning about potential safety risks of long trains blocking rail crossings, in response to Norfolk Southern derailments in Springfield and Ravenna, Ohio, and a Union Pacific derailment in Rockwell, Iowa.