COMPOSITION BRAKE BLOCKS. LIMITS OF ENERGY DISSIPATION DURING BRAKING WITH TYRED WHEELS

A large number of continuous braking tests have been carried out, on the brake test plant of the Laboratory for Vehicle Technology of Delft Technical University, using tyred wheels with both cast iron and composition brake blocks. These tests were commissioned by ORE B 64 and by the CFF. It was hoped by this means to establish a relationship between braking power and the time during which the relevant braking power could be tolerated by the wheel without detriment. The limit laid down was the so called loosening time according to Bodey's temperature criterion (Bibliography reference 1). This limit is the instant at which the tyre begins to loosen on the wheel centre. The loosening time is determined by continuous measurement of the temperatures in the vicinity of the shrink fit surfaces. Knowledge of the relationship between loosening time and brake power, i.e. what may be described as the limit of braking power, permits the greatest possible braking of vehicles to be determined, with the wheels in question, in relation to the axle load and to the route to be run over. The present report contains the most important part of the results of the tests carried out. The three wheels tested, of 900 mm mean diameter with different shrinkage allowances and tyre thicknesses represented a new wheel with maximum shrinkage allowance; a half-worn wheel and a wheel of the smallest permissible tread diameter with minimum shrinkage allowance, that is to say the entire range occurring in practices.

• Supplemental Notes:
  • Restrictions on the use of this document are contained in the explanatory material.
• Corporate Authors:

  International Union of Railways

  Office of Research and Experiments
  Utrecht,   Netherlands 
• Publication Date: 1968-10

Media Info

• Features: Appendices; Figures; Tables;
• Pagination: 26 p.

Subject/Index Terms

• TRT Terms: Brake shoes; Brakes; Braking; Braking performance; Composite materials; Measuring instruments; Tests; Vehicle tests
• Old TRIS Terms: Brake tests; Question b64
• Subject Areas: Railroads; Vehicles and Equipment;

Filing Info

• Accession Number: 00052939
• Record Type: Publication
• Source Agency: International Union of Railways
• Report/Paper Numbers: B64/RP 5/E
• Files: TRIS
• Created Date: Sep 16 1976 12:00AM