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.
East Coast Main Line
The ECML has been the backdrop for a number of significant rail journeys and locomotives. The line was worked for many years by Pacific locomotives designed by Sir Nigel Gresley, including the steam locomotives "Flying Scotsman" and "Mallard". Mallard achieved a world record speed for a steam locomotive, having attained a recorded top speed of , while traversing the Grantham-to-Peterborough section on the descent of Stoke Bank. To date, the speed record set by Mallard has not been broken.