Nigel Gresley
Sir Herbert Nigel Gresley (19 June 1876 – 5 April 1941) was an English railway engineer. He was one of Britain's most famous steam locomotive engineers, who rose to become Chief Mechanical Engineer (CME) of the London and North Eastern Railway (LNER). He was the designer of some of the most famous steam locomotives in Britain, including the LNER Class A1 and LNER Class A4 4-6-2 Pacific engines. An A1 Pacific, "Flying Scotsman", was the first steam locomotive officially recorded over 100 mph in passenger service, and an A4, number 4468 "Mallard", still holds the record for being the fastest steam locomotive in the world (126 mph).
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.