S
WRailway brake
WDisc brakeA
WDynamic braking
WEddy current brakeB
WEmergency brake (train)
WHeberlein brakeC
WKunze-Knorr brake
WPearson's CouplingD
WRailway air brake
WRegenerative brakeE
WTrack brake
WVacuum brakeF
WVacuum brake
WWestinghouse Air Brake Company