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.
History of rail transport in Great Britain 1923–1947
The first chief mechanical engineer of the LNER was Sir Nigel Gresley, who held the post for most of the LNER's life. He was noted for his "Big Engine" policy, and is best remembered for his large express passenger locomotives, many times the holder of the world speed record for steam locomotives. LNER Class A4 4-6-2 Pacific locomotive "Mallard" still holds the land speed record for a steam locomotive. Gresley died in office in 1941.