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.
Prussian G 5.1
The Prussian Class G 5.1 steam engines were the first 2-6-0 goods locomotives in Europe. They were developed for the Prussian state railways from the Class G 4 and a total of no less than 268 units of this class were placed in service in Prussia between 1892 and 1902. The twin-cylinder G 5.1 had been designed to raise the speed of goods trains on main lines. In addition, more powerful engines were needed for the increasingly heavy train loads. The locomotives, which were equipped with a compressed air brake, were used in charge of fast goods trains ("Eilgüterzugdienst") and also passenger trains due to their impressive top speed of 65 km/h. The G 5.1 was fitted with inside Allan valve gear and the carrying wheels were of the Adams axle design.