Robert Francis Fairlie (born either March 1831 or 5 April 1830, in Glasgow, died 31 July 1885, in London) was a Scottish-born railway engineer.
Fairlie was born in Glasgow, the son of T. Archibald Fairlie (an engineer) and Margaret Fairlie. He trained at Crewe and Swindon railway works, then joined first the Londonderry and Coleraine Railway as Locomotive Superintendent in 1852, and four years later the Bombay, Baroda & Central India Railway before returning to London in 1859 to establish himself as a railway engineering consultant.
He is chiefly known for the invention of the Fairlie double-bogie articulated locomotive (patented in 1864) that is particularly associated with tightly curved railways and especially narrow gauge mountain lines. The first such, the Pioneer, was built in 1865 for the Neath and Brecon Railway, but it was with the Little Wonder built in 1869 for the Festiniog Railway that Fairlie made his name as the inventor of something special.
On the Festiniog Railway the new engine could be tested against not one but six engines all of the same tried and tested and improved design (the first ever successful narrow gauge steam locomotive design) and they all came from the locomotive works of George England and Co., the Hatcham Ironworks, Pomeroy Street, New Cross, London, where the Little Wonder was also built. A series of tests, for which detailed performance records survive, were held between 18 September 1869 and 8 July 1870.
It was to the Festiniog Railway in north Wales, the first and the narrowest of narrow gauge railways, on 11 February 1870, in the middle of winter, that Fairlie invited locomotive engineers, and their principals, from all over the world, and from all over the world they came, as reported by the north Wales newspapers: The Duke of Sutherland; Mr W. T. Mulvany, from Prussia; M. Tolme, engineer; M. Phillippe Kremer from Paris, engaged on the Moscow and Nizhny Novgorod Railway; Mr Christer P. Sandberg, Swedish Consulate, London; Count Czheni, Russia; Count Alexander Berg, son of the generalissimo of the Russian army, and Viceroy of Poland; Count Bobrinski, Russia; Count Tamoyski, Hungary; Basiley Saloff, Professor of the Imperial Institute of Engineers, St. Petersburg; Charles de Schouberszki, director of the Kursk and Kharkov Railway in Russia; Count Ivan Tlabroburr, Moscow; Count von Desen, St. Petersburg; L. de Kislankske, of the Imperial Institute, St. Petersburg; Mr Preston, solicitor to the London and North Western Railway Company; Capt. Tyler, Government Inspecting Officer for Railways; Mr Preston, engaged on the railway from Tiflis to the Caucasus, in Turkey and Russia; Gen. Sir William Baker, K.C.B.; Mr Power, M.P ., connected with the Mexico and Vera Cruz Railways; Mr Pille [i.e. Carl Abraham Pihl], Sweden; Mr Ayrton, Mr Elias, general manager, Cambrian Railways; Mr Poole, local traffic manager ditto; Mr Charles E. Spooner, engineer, Festiniog Railway Company; Mr Crawley, C.E., London; Mr Danas, Indian Railways; Mr C. Thornton, ditto; Mr Livingston Thompson, Chairman and managing director, Festiniog Railway Company; Mr Dallas, The Times newspaper, and Mr Thomas Cargill, engineer & reporter of the Engineering Gazette – and many others! Further parties of engineers and managers came to Porthmadog on four later occasions in 1870 to observe the locomotive at work.