1938 Mallard's World Speed Record.

On Sunday 3 July 1938, during a series of high-speed brake trials on the main line between Peterborough and Grantham, UK, the opportunity was taken to make an attempt on the world speed record for railways, using the locomotive Mallard.

Although the load was far less than a full train, it was no light weight either, with 3 twin-articulated carriages set and the company’s dynamometer car, making 7 vehicles in all with an empty weight of 236.5 tons, or 240 tons with officials and equipment aboard.

Mallard was chosen because she was 1 of 3 A4 locomotives to have the Kylchap exhaust arrangements, which included a double blast-pipe chimney.

Mallard took her carriages through Grantham station at just 39km/h because of permanent way work, and then accelerated to almost 100km/h over the next two and a half miles up a rising gradient of 1 in 200, eventually reaching almost 120km/h over the next mile-and-a-half to Summit Stoke.

Descending Stoke Bank, the speed rose to 185km/h where it stayed for the next three miles. Finally, the maximum registered speed was 203km/h.

The locomotive maintained a speed of 203km/h for two miles.

The record-breaking run was then curtailed as the opportunity was taken to conduct a brake test from such a high speed and the train was approaching the curve at Essendine, which also included several sets of points, and it was thought unwise to take these at such a high speed.

This was a greater achievement than generally realised, not just because it has never been beaten anywhere, but because far from being specially prepared, Mallard had worn valves and was driven hard by its driver J. Duddington of Doncaster, known for thrashing his locomotives. Had she been properly prepared and all valve clearances correct, the record might have been set even higher.

As it was, those on the footplate could smell the machinery at is overheated and the locomotive needed major workshop attention afterwards.

Many claim that the locomotives of the day operating in the United States and Germany could have matched or even exceeded this record, but the point is that they didn’t.

Mallard retired from service in 1963 and was subsequently preserved in 1964 by the British Transport Commission. In 1975 Mallard entered the National Railway Museum's collection in York. Today Mallard remains one of the highlights of the National Railway Museum.