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.
Norfolk and Western 1218
During 1218's excursion career, it was the most powerful operational steam locomotive in the world, with a tractive effort of , well above the next-strongest-pulling operational steam locomotive (Union Pacific 3985, with a tractive effort of ). However, when Union Pacific 4014 finishes its restoration, 1218 will become the locomotive with the second highest tractive effort. Unlike diesel-electric locomotives of similar high tractive effort (for starting heavy trains) but typical for a steam locomotive, it could easily run at 70 miles per hour (113 km/h) and more.