Mallard and the steam speed record
In the 1930s the British railways competed with each other and with the roads in speed. The London and North Eastern Railway had in 1934 taken the first officially authenticated 100 mph by a steam locomotive with Flying Scotsman, and then ordered a series of streamlined engines for its express trains, designed by Nigel Gresley.
One of these, number 4468 Mallard, made a special run on 3 July 1938 on the East Coast main line south of Grantham. The train was a test, made officially to try a new type of brake, and a dynamometer car recorded the figures. On Stoke Bank, a long descent, the locomotive reached 126 miles an hour (203 km/h), a world record for steam that still stands.
What it cost
The run was hard on the engine: the middle big-end bearing overheated and the locomotive had to be taken out of service at Peterborough. The record was reached by a combination of a long downhill, a light train of seven coaches and a good deal of skill by the crew. Mallard was withdrawn in 1963 and is now at the National Railway Museum in York, in the company of other locomotives from the golden age of steam.