Other Reports

Report Number 13 - Examination of Failed Railroad Car Wheel/Axle Assembly from Derailed Passenger Car, McIntosh, Georgia

  • 01
  • Jun
  • 1986
AUTHOR: T. R. Shives, S. R. Low III, C. H. Brady
SUBJECT: Accident Investigations
KEYWORDS: Derailment, Amtrak, Fracture, Safety
ABSTRACT: At the Request of the Federal Railroad Administration, the National Bureau of Standards conducted an examination of a failed wheel assembly from an Amtrak passenger car involved in a derailment at McIntosh, Georgia. The west lead wheel of the trailing truck of the car was found to have a radial fracture which permitted the wheel to move laterally along the axle. The east wheel had suffered a chordal fracture. The apparent sequence of events is the radial fracture of the west wheel followed by lateral motion of that wheel along the axle which permitted the east wheel to drop in the gauge of the track causing the derailment. The fracture of the east wheel was thought to be a result of the derailment. The west wheel fractured from a crack that initiated at the outside of the tread. There was evidence of a pre-existing crack in the fracture path near the fracture origin, although it is not clear that this crack initiated the fracture. The fracture of the east wheel also initiated at the outside of the tread. There was a gouge near the fracture origin and the fracture passed through a dent, but it is not clear that there is any relationship between either of these areas of mechanical damage and the fracture. In addition to the fracture crack, two radial cracks were found at the tread of the west wheel. One of these cracks was associated with an inclusion. Although both wheels appear basically to satisfy AAR specifications for B-36 wheels, some dimensions did not comply and hardness of the west wheel was marginal in some places.