DISC BRAKES : CONTRIBUTION TO THE STUDY OF THEIR RATIONAL USE ON RAILWAY VEHICLES
LE FREIN A DISQUES CONTRIBUTION A L'ETUDE DE SON UTILIZATION RATIONELLE SUR LES VEHICULES FERROVIAIRES
Braking problems have become more complicated with highspeed running and, in solving them, greater consideration must be given to the inherent characteristics of disc brakes which are quite different from those of conventional brakes with cast-iron blocks. Initially, disc brakes are generally more expensive to install than shoe brakes but under actual operating conditions they can be more economical provided the discs last sufficiently long and the quality of the linings is good. The study of the basic phenomena which distinguish the operation of this brake system has been undertaken at the international level by the UIC Braking Sub-Committee. The article draws attention to the importance of the assembly of the discs and their mechanical arrangement which must allow for the expansion caused by heating when the brakes are applied. The work carried out includes the determination, on the brake testing plant at Vitry, of the maximum performance obtainable both for holding braking and braking to a stop, with given axle loads, average decelerations and speeds. A further study, based initially on theoretical calculations and the use of a computer, has shown the importance of the average diameter of the disc on the performance obtainable. The study also includes the examination of the adhesion conditions that are feasible on polluted rail, compared with brakes with cast-iron blocks. An effective solution has been proposed for curing the adhesion defects noted with disc brakes in the case of high performances. The study has also highlighted the importance of the linings on the performance that can be obtained with disc brakes, and how this performance can drop in the case of exceptional weather conditions (snow and low temperatures). Line tests, under difficult winter conditions, have enabled these phenomena to be determined with precision.
-
Corporate Authors:
Societe Nationale des Chemins de Fer Francais
92 rue Bonaparte
75 Paris 6e, France -
Authors:
- Lapaiche, H
- Publication Date: 1972-7
Language
- French
Media Info
Subject/Index Terms
- TRT Terms: Brakes; Disc brakes; Technology
- Geographic Terms: France
- Old TRIS Terms: Braking systems
- Subject Areas: Railroads; Vehicles and Equipment;
Filing Info
- Accession Number: 00047800
- Record Type: Publication
- Source Agency: International Union of Railways
- Files: TRIS
- Created Date: Jan 4 1976 12:00AM