FRA Completes Reports on Long Trains

Three reports on safety and performance of long trains have been finished by the Federal Railroad Administration and sent to the National Academy of Sciences.

The reports were part of a study mandated by the Infrastructure Investment and Jobs Act of 2021.

The study looked at trains longer than 7,500 feet. In a statement the FRA said it is seeking more transparency and data regarding long trains..

The reports contain 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’s research team also conducted tests on a moving train to better understand the dynamic performance of long trains and to collect data on train dynamics and brake system performance.

The research found air brake systems performed largely as expected when testing was performed under ideal circumstances and in a controlled environment.

However, the reports identified negative impacts on safety and performance. Key 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.

Titled Phase II, Phase III and Phase IV, the reports are available online.

Tags: Federal Railroad Administration, long trains, National Academy of Sciences