DYNAMIC TESTS OF FREIGHT CAR TRUCKS UNDER MECHANICAL REFRIGERATOR CARS 70 TON CAPACITY

The objective of these tests was a comparison of the ride characteristics of the various designs of premium type trucks currently being marketed with the ride characteristics of the AAR standard friction snubbed truck. The trucks tested included: The AAR standard 70 ton, narrow pedestal roller bearing truck. The XL-70 truck, the Rockwell Express truck, the National Castings Division truck, and the Chevron freight truck. The following conclusions were reached: Vertical forces received by the car body floor were not adequately snubbed or controlled by any of the five trucks tested. Lateral force levels at the car body floor were at a low amplitude with all of the trucks tested with new wheels with the exception of the GSI Chevron truck. Lateral car body force reactions to rail joints and other track irregularities increased materially at higher speeds and when worn wheels were substituted for new wheels, especially with the AAR standard truck and the XL-70 Syminton Wayne truck. The spring plank swing motion arrangement on the National Swing Motion truck showed excellent control of car body lateral force levels, while the Transom linked side frames of the Rockwell Express truck showed acceptable control of these force levels. Vertical and lateral force levels were lowered when speed was reduced, but they did not reach acceptable levels until below 50 mph.

• Supplemental Notes:
  • Joint report by Southern Pacific, Union Pacific and Pacific Fruit Express, January 1971.
• Corporate Authors:

  Pacific Fruit Express

  Roseville, CA  United States 

  Southern Pacific Company

  65 Market Street
  San Francisco, CA  United States  94105

  Union Pacific Railroad

  1416 Dodge Street
  Omaha, NE  United States  68102
• Publication Date: 1971-1

Media Info

• Features: Figures; Photos; Tables;
• Pagination: 47 p.

Subject/Index Terms

• TRT Terms: Bearings; Defects; Dynamic loads; Dynamics; Motor vehicle bodies; Rail joints; Railroad cars; Railroad tracks; Refrigerator cars; Ride quality; Snubbers; Suspension systems; Suspensions; Technology; Trucks; Vehicle design; Vehicle dynamics; Wear; Wheels; Wheelsets (Railroads)
• Uncontrolled Terms: Lateral dynamics; Vertical dynamics
• Geographic Terms: United States
• Old TRIS Terms: Car body; Track irregularities
• Subject Areas: Design; Motor Carriers; Railroads; Vehicles and Equipment;

Filing Info

• Accession Number: 00039696
• Record Type: Publication
• Report/Paper Numbers: Tech Rpt
• Files: TRIS
• Created Date: Jan 5 1976 12:00AM