Technical Reports

Stub Sill Tank Car Research Project Results of a 15,000-mile over-the-road Test

  • 01
  • Sep
  • 1995
AUTHOR: Lowell T. Cogburn
SUBJECT: Hazardous Materials
KEYWORDS: verticle coupler force; fatigue damage; NCF Historgam; LCF Histogram; impact time histories; OTR Testing; FEEST Data
ABSTRACT: The Federal Railroad Administration (FRA) contracted with the Association of American Railroads (AAR), Transportation Test Center (TTC) - now known as the Transportation Technology Center - Pueblo, Colorado, to study in-revenue service loads on stub sill constructed tank cars. Over 162,000 of these cars have been placed into service since 1950. The FRA has been investigating incidents of fatigue cracking at the attachment of the stub sill to the tank shell of these cars. As a result, the FRA has undertaken a program to work with industry representatives to further investigate the causes of the fatigue cracking and recommend preventative measures. Results from the over-the-road (OTR) testing showed that the highest surge pressures experienced never exceeded 40 psi. OTR testing resulted in obtaining vertical coupler force and longitudinal coupler force histograms for typical environments experienced by tank cars. Representative time history events were obtained that suggest a possible source of VCF's responsible for a high percentage of total fatigue damage experienced by tank cars.