The purpose of this study was to observe controlled tests and fine solutions for harmonic roll in 100-ton hopper cars during low speed operation on staggered joint track which initiated wheel lift and subsequent derailment. These studies indicated that lower spring rates, extended center of the spring nests, applied swivel center plates, and preloaded laminated side bearings can be attenuated but not fully eliminated. Also, some improvement has veen obtained by permitting more lateral between the side frame and the bolster, in the bearing system, and by reducing the distance between the centers of the side bearings. Experimental truck arrangements are being developed which will permit the truck to follow the irregularities of track and which will prevent the introduction of the forcing frequency into the body of the car at such a phasing as to cause harmonics in the car rolling. Also, snubbing and energy absorption are being studied from a theoretical standpoint and practical applications of snubbers have been made which help to reduce the incidence of wheel lift when the snubbers are applied in combination with other changes.

Media Info

  • Features: Figures; Tables;
  • Pagination: 23 p.

Subject/Index Terms

Filing Info

  • Accession Number: 00040352
  • Record Type: Publication
  • Report/Paper Numbers: AAR-MR-440 Prog Rpt
  • Files: TRIS
  • Created Date: Jul 8 1994 12:00AM