CHARACTERIZING THE PERFORMANCE OF CAST-IRON, HIGH-PHOSPHORUS CAST-IRON, AND COMPOSITION FREIGHT CAR BRAKE SHOES UNDER SIMULATED DRAG BRAKING CONDITIONS

The performance of the cast-iron, high-phosphorus cast-iron, and composition brake shoes was evaluated through a test program under conditions simulating the operation of a loaded 70-ton freight car on a long downgrade or "stuck brake" situation. The major part of the test program dealt with brake tests at constant speeds of 20, 30, and 40 mph with about 30 bhp energy-dissipation rate. Additional tests included simulating "worst-usage cases" and those conducted to determine the effects of a rolling-contact load, partial shoe contact, and brake-shoe force magnitude on the performance of three types of shoes. During each test, the braking torque, the wheel temperature, and the strain in the wheel were measured. The major conclusions of the study are: The brake-shoe force ratios of 1:1:0.5 currently used for the cast-iron, high-phosphorus cast-iron, and composition shoes should be reconsidered; The current ratios could be a contributing factor in overheating of the wheel; and Using a composition shoe by mistake in a brake-rigging meant for a cast-iron shoe could lead to a wheel failure.

• Corporate Authors:

  Little (Arthur D), Incorporated

  Acorn Park
  Cambridge, MA  United States  02140

  Federal Railroad Administration

  Office of Research and Development, 1200 New Jersey Avenue, SE
  Washington, DC  United States  20590
• Authors:
  • Boghani, A B
• Publication Date: 1981-1

Media Info

• Features: Figures; References; Tables;
• Pagination: 54 p.

Subject/Index Terms

• TRT Terms: Brake shoes; Braking; Braking performance; Casting; Composite materials; Dynamometers; Failure; Phosphorus; Ratios; Tests; Thermal stresses; Wheels
• Old TRIS Terms: Braking ratios; Wheel failure; Wheel thermal stresses
• Subject Areas: Railroads; Vehicles and Equipment;

Filing Info

• Accession Number: 00341258
• Record Type: Publication
• Report/Paper Numbers: FRA/ORD-81/08 Final Rpt., ADL-80589-75
• Contract Numbers: DOT-FR-74261
• Files: TRIS, USDOT
• Created Date: Aug 15 1981 12:00AM