Brake Usage in a Heavy Vehicle

This paper summarizes measurements made of the duties imposed on the brakes of a heavy vehicle when driven over a continental route which included the Susten and other passes in Switzerland and in Austria. On the Susten Pass an investigation was made of the effect of driving in various gears.The following data were determined for each brake application: vehicle deceleration, rate of energy dissipation and total energy dissipated at the brakes, the energy lost by drag losses, the energy absorbed by engine braking, and the temperatures attained in all drums and linings. Measurements were also made of the amount of energy imparted to the vehicle when it was accelerated by the engine between brake applications.Analysis of the results shows that a heavy vehicle travels at a fairly uniform speed down the mountain passes and consequently only a small percentage of the total energy dissipated is given to the vehicle by the engine in between braking. The work done at the brakes varied between 15 and 62 per cent of...