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).
Norfolk and Western 1218
During 1218's excursion career, it was the most powerful operational steam locomotive in the world, with a tractive effort of , well above the next-strongest-pulling operational steam locomotive (Union Pacific 3985, with a tractive effort of ). However, when Union Pacific 4014 finishes its restoration, 1218 will become the locomotive with the second highest tractive effort. Unlike diesel-electric locomotives of similar high tractive effort (for starting heavy trains) but typical for a steam locomotive, it could easily run at 70 miles per hour (113 km/h) and more.