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).
John Bull (locomotive)
The running gear seemed to be in good order, but it was still unknown if the boiler could still handle the pressure of steam and a live fire again. The museum asked the Hartford Steam Boiler Inspection and Insurance Company to inspect the locomotive's boiler for operation. The inspections were conducted after hours at the museum (from 6:30 p.m. to 4:00 a.m.) over three days and included electromagnetic, ultrasonic, and radiographic tests. The tests did reveal a few flaws, but it was projected that the engine could operate at a reduced boiler pressure of 50 psi (340 kPa or 3.5 kgf/cm²); as delivered to the Camden & Amboy, the boiler was rated for or 4.9 kgf/cm². The Smithsonian's staff, after a few further hydrostatic tests, were confident that the locomotive could again operate under its own power. The items that needed repair were repaired, and on October 14, 1980, the locomotive was successfully field-tested on the Warrenton Branch Line in Fauquier County between Calverton and Casanova, Virginia. The site was selected, because at the time, only one freight train per week used the branch line. On September 15, 1981, the locomotive operated under steam on a few miles of branch line near the Potomac River within Washington, D.C. With this exhibition, the locomotive became the oldest operable steam locomotive (and oldest self-propelled vehicle) in the world.