He is chiefly known for the invention of the Fairlie double-bogie articulated locomotive 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 locomotive was tested against the railway's existing George England and Co. four-coupled tank locomotives. A series of tests, for which detailed performance records survive, were held between 18 September 1869 and 8 July 1870. today. On 11 February 1870, a formal demonstration was held, for invited guests from around the world, including: 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, SwedishConsulate, 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 , 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 Further parties of engineers and managers came to Porthmadog on four later occasions in 1870 to observe the locomotive at work. Fairlie received many orders and commissions following the trials. In 1873-1874 he travelled to Venezuela, but this trip resulted in a serious illness. By 1876 forty three railways operated Fairlie's patent locomotives, not always successfully.
Elopement and marriage
However, Robert Fairlie's professional career and social standing had been seriously threatened eight years earlier by a remarkable case brought against him in the Central Criminal Court by his longtime business associate, George England, who alleged perjury on the part of Robert Francis Fairlie who had eloped with England's daughter Eliza Anne England and, to procure a marriage licence, had sworn a false affidavit that her father, Mr George England, had consented to the union, which was not true. After this marriage they had run away to Spain. This accusation would, if proved, have resulted in a prison sentence. Under cross-examination by Sergeant Ballantyne, George England was forced to admit that he had run away with his present wife, who was the mother of the young lady in question, and that he had a wife living at that time. He had lived with this lady several years but could not marry her until his wife died. By a quirk of English law, at that time, a child born out of wedlock was considered nobody's child. In law she was nothing to do with George England and could marry whom she pleased. There was no case to answer and therefore a verdict of not guilty was returned. But none of this stopped George England building Robert Fairlie's remarkable double-engine for the Ffestiniog Railway seven years later. Fairlie's Little Wonder was delivered to the FR in the summer of 1869 and George England retired. In September 1869 Robert Fairlie joined with George England's son and J.S. Fraser to take over the Hatcham Works and to form the Fairlie Engine & Steam Carriage Co. but George England junior died within a few months. Locomotive production ceased at the end of 1870 but the Fairlie Engine & Rolling Stock Co. continued as an office for design and for the licensing of Fairlie locomotive manufacture. George England died in 1878, and by 1881 Fairlie and his wife Eliza were living at 13 Church Buildings, Clapham with their children, Robert, John, Lily and Jessie and Robert's mother in law, Sarah England. Robert Francis Fairlie died in London on 31 July 1885 and is buried at West Norwood Cemetery.
