Mainline steam trains in Great Britain
The most famous steam locomotive operating on the British main line is the 1923 built "Flying Scotsman". After being taken into public ownership in 2004, following a decade long refit it returned to mainline service in 2016. The fastest steam locomotive ever built, the 1938 built "Mallard", was also certified for main line operation briefly in the 1980s.
GNRI Class Q
Faster running was achieved with the addition of superheated boilers and widened cylinders (under the supervision of G.T. Glover in the 1920s). In 1932 a two coach newspaper train hauled by No. 135 covered Howth Junction to Drogheda at a start-to-stop average speed of , the fastest run in Ireland achieved with a steam locomotive on a scheduled train