FRA Finalizes Research Reports on Long Trains

FRA said its three recently finalized reports on the “safety and performance of long trains” include findings from tests conducted on air brake racks (pictured) and the air brake system of a stationary train to examine how the length of long trains affects air brake system behavior and performance. (Photograph Courtesy of FRA)

The Federal Railroad Administration (FRA) on May 22 announced that it has finalized three reports on the “safety and performance of long trains,” which have been submitted to the National Academy of Sciences (NAS) to inform “an ongoing NAS study mandated by Congress in President Biden’s Bipartisan Infrastructure Law to look at the impact of trains longer than 7,500 feet.”

According to FRA, the reports include findings from tests conducted on air brake racks and the air brake system of a stationary train to examine how the length of long trains affects air brake system behavior and performance. FRA said its research team also conducted tests on a moving train “to better understand the dynamic performance of long trains and collect data on train dynamics and brake system performance.”

Research from the reports—Phase II, Phase III, and Phase IV (scroll down to download)—found that “air brake systems performed largely as expected when testing was performed under ideal circumstances and in a controlled environment,” FRA said. But the federal agency noted that they “identified negative impacts on safety and performance.”

According to FRA, key report findings include:

• “Phase II of testing, using only head-end power, found that the likelihood of unintended brake releases was higher with longer trains and that increased train lengths led to slightly slower brake response times.
• “Phase III of testing found that distributed power train configurations achieve better braking capability than only head-end power on long train operations.
• “Phase IV of testing found when long trains climbed a grade, certain sections of the train consist experienced elevated buff forces and coupler forces, which can influence how a train behaves and impact the safe handling of trains with distributed power.
• “Phase IV of testing concluded that further testing is needed to identify potential safety gaps when operating long trains in non-ideal operating conditions.
• “The research team also made clear in Phase IV, the final phase of testing, that additional research, testing and analysis is recommended to provide a better understanding of how long trains impact the durability of rolling stock mechanical components.”

FRA said there is “no federal statute regarding restricting train length nor one on how long trains may block crossings,” but noted that “FRA-led efforts are under way to gather more information on long trains at the federal level and improve incident data collection on train length.”

The federal agency added that it has previously “expressed growing concern related to train makeup and the complexities associated with operating longer trains.” On April 27, 2023, it issued Safety Advisory 2023-03, Accident Mitigation and Train Length, “to increase awareness of the potential complexities associated with operating longer trains, and push railroads to take appropriate measures to address those complexities to ensure safety”; the notice “also makes clear that train length, just like train makeup, is a critical factor to consider when building any train,” FRA said upon the advisory’s release. That Safety Advisory built on FRA Safety Advisory 2023-02, issued April 10, 2023, which was focused primarily on train makeup; FRA said at the time of its release that it was “to emphasize significant concerns related to train makeup and to ensure that all railroads exercise due diligence and recognize the importance of taking proactive measures to address potential safety risks related to operating train builds with varying configurations, load and empty placement and DPU (Distributed Power Unit) arrangements.” FRA added that the action was based on “a rising trend in recent incidents where train build and makeup have been identified as a potential cause or contributing factor. In response, FRA incorporates train simulations into its investigative process when it is suspected that high in-train forces may have contributed to train accidents. To address these concerns, FRA is providing recommendations for freight railroads to improve the safety of their train build processes and practices.”

DOWNLOAD THE THREE FRA-FINALIZED REPORTS BELOW: