LNER Class A4 4468 Mallard
London and North Eastern Railway locomotive numbered 4468 "Mallard" is a Class A4 4-6-2 Pacific steam locomotive built at Doncaster Works, England in 1938. It is historically significant as the holder of the world speed record for steam locomotives at .
James Holden (locomotive engineer)
The Decapod developed mainly under Chief Draughtsman Frederick Vernon Russell was an extraordinary endeavour to develop a steam locomotive which could perform at the level of electric traction. It was built in 1902 to forestall an imminent scheme for an electrified railway out of London to suburbs served by the GER. Since the proponents of the scheme had a slogan about electric trains accelerating to thirty miles an hour in thirty seconds, Holden resolved to obtain the same performance with steam traction. A massive boiler with Wootten firebox, three cylinders each with its own blastpipe cone, and ten smallish driving wheels ensured a lively acceleration. On trial it did rather better than 30 mi/h (50 km/h) in thirty seconds, accelerating at 1.46 ft/s² (0.45 m/s²): This performance put an end to the electrification scheme even though (as Holden had known all the time) the regular use of so massive a machine would never have been permitted by the civil engineer.