Abstract :
ELECTROPNEUMATIC brakes for main-line high-speed passenger trains are a recent innovation. Electropneumatic brakes have, however, been known and used for many years. The first steam road tests were made in 1887. The results were quite gratifying, but improvements in the pneumatic apparatus resulted in such satisfactory performance that the added expense and complication of electropneumatic control was clearly not warranted. Electropneumatic brakes have been used, however, in subway and elevated service, and in considerable quantity, for more than 30 years.