Technical Reports

High Cant Deficiency Testing of the LRC Train, the AEM-7 Locomotive, and the Amcoach

  • 01
  • Jan
  • 1982
AUTHOR: P.L. Boyd, R.E. Scofield, J.P. Zaiko
SUBJECT: Amtrak, Facilities & Test Equipment
KEYWORDS: Curving Safety, High Speed Curving
ABSTRACT: Increasing the speed of passenger trains in existing curves has been proposed as an alternative to changing curve radii for the purpose of reducing trip times on the Northeast Corridor. This test evaluates safety at high cant deficiency by comparing direct wheel/rail force measurements to safety criteria from world-wide sources. Tests were performed on the advanced LRC train with banking coaches and the modern but conventional AEM-7 Locomotive and Amcoach. The criteria concerning safety against vehicle overturning set the cant deficiency limits of all four vehicles, and the crosswind allowance set lower limits for coaches than for locomotives. A typical curve limited to 60 mph by the current 3 inch cant deficiency limit could be negotiated by the LRC train at UP to approximately 79 mph (9 inches cant deficiency) while holding the steady state lateral acceleration below the AAR ride comfort criterion of 0.1g. A conventional train with standard Amcoaches towed by an AEM-7 locomotive could negotiate the same curve safely at up to about 76 mph (8 inches cant deficiency), but the steady state lateral acceleration in the coach would increase to about 0 .15g. This level of lateral acceleration is acceptable by the SNCF (French National Railway) criterion, but it is considered "strongly noticeable" by the AAR .