LOCOMOTIVECompressor + brake valve
BRAKE PIPE — runs through the train
CAR 1Reservoir • valve • cylinder
CAR 2Reservoir • valve • cylinder
CAR 3Reservoir • valve • cylinder
Charge & release
Brake-pipe pressure charges car reservoirs and keeps the automatic brakes released.
Service application
Reducing brake-pipe pressure causes each car to send reservoir air to its brake cylinder.
Emergency
A rapid, large pressure reduction commands an emergency application.