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.
4-4-2 (locomotive)
The locomotives were cross balanced and ran on drivers. They had an oil-fired grate and a rated boiler pressure of , which gave the boiler a high capacity in relation to the cylinders. Designed for a light-weight train of five to six passenger cars, they were considered as probably the fastest steam locomotives ever built in the United States, possibly capable of matching any locomotive in the world. The fleet covered their schedule in 400 minutes with several stops en route, at an average speed of more than on some sections and often arriving with one or two minutes to spare.