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Impact of Shoulder Cleaning on Ballast Drainage

Document Series
Research Results
Federal Railroad Administration
Report Number
RR 22-38
Subject Track
Mud pumping, settlement, degraded ballast

The Federal Railroad Administration (FRA) and the Association of American Railroads (AAR) jointly supported Transportation Technology Center, Inc., (TTCI) to investigate the influence of shoulder ballast cleaning (SBC) on the performance of fine-filled ballast. Repeated vehicle loadings degrade ballast particles over time and can eventually allow enough degraded ballast fines to accumulate around the tie ends to block drainage. This blocked drainage can then produce mud pumping and rapid track geometry degradation and can also accelerate track component degradation. Testing was conducted between 2021 and 2022 at the “Rainy Section,” a degraded ballast test section at the Facility for Accelerated Service Testing (FAST) in Pueblo, CO. Research findings indicate better shoulder drainage resulting from shoulder cleaning can improve drainage capacity, reduce surface mud pumping, and reduce track settlement in certain situations. 

Last updated: Tuesday, November 22, 2022