SYMPOSIUM ON BRAKING SYSTEMS IN RAILWAYS: CONSIDERATIONS ON PRESENT BRAKING PROBLEMS OF RAILWAY CARRIAGES

ONE OF THE MAIN CHARACTERISTICS IN THE PRESENT RAILWAY EVOLUTION IS THE INCREASE IN THE SPEED OF PASSENGER TRAINS, WHICH GIVES RISE TO NUMEROUS AND COMPLEX PROBLEMS, IN PARTICULAR BRAKING PROBLEMS. THIS REPORT CLASSIFIES THE DIFFERENT CATEGORIES OF BRAKES: FRICTION BRAKES AND DYNAMIC BRAKES. THE LATTER CAN BE SATISFACTORILY ADAPTED TO HIGH SPEED, THEIR OPERATION IS ECONOMICAL AND THEIR ADJUSTMENT SATISFACTORY. THEY ARE ALSO EFFECTIVE FOR A WIDE RANGE OF SPEEDS. IN MOST CASES THIS EFFECTIVENESS DECREASES WITH SPEED, AND AN ADDITIONAL FRICTION BRAKE IS NECESSARY TO ENSURE THAT THE TRAIN COMES TO A STANDSTILL. IT IS NECESSARY TO HAVE A THOROUGH KNOWLEDGE OF THE BRAKE CHARACTERISTICS WHICH INFLUENCE THE LIMITS OF USE AS A FUNCTION OF SPEED, MASS PER AXLE, DECELERATION REQUIRED, ENERGY CONSUMPTION NECESSARY FOR OPERATION, EASE AND ACCURACY OF ADJUSTMENT. THEIR BASIC QUALITIES ARE RELIABILITY AND EFFICIENCY, AND AS LOW COSTS AS POSSIBLE. A TABLE SHOWS THE DIFFERENT TYPES OF BRAKE. SHOE BRAKES CAN BE USED FOR SPEED UP TO 160 KM/H AND ELECTROMAGNETIC BRAKES UP TO 200 KM/H. AMONG DYNAMIC BRAKES, MENTION IS MADE OF LINEAR BRAKES OPERATING WITH FOUCAULT CURRENT. DETAILS ARE ALSO GIVEN OF THE SENF BRAKES AND DISC BRAKES FOR HIGH SPEED. SEE IRRD ABSTRACTS NOS 106206 TO 106213.