Milwaukee Road class F7
The F7s are major contenders for the fastest steam locomotives ever built, as they ran at over daily. One run in January 1941 recorded by a reporter for "Trains" magazine saw achieved twice—in the midst of a heavy snowstorm. Baron Gérard Vuillet, a French railroading expert, once recorded a run between Chicago and Milwaukee where the locomotive reached and sustained an average for . However, the British locomotive LNER Class A4 4468 "Mallard" is officially accepted to be the world's fastest, with a run recorded at but authenticated at 126 mph in 1938.
West Coast Railway (Victoria)
Specially modified R class steam locomotives were also used to operate a Saturday return service, becoming the fastest regular steam hauled passenger service in the world. R711 entered service on regular trains on 21 November 1998 and was fitted with multiple unit control equipment for diesel electric locomotives.