LNER Class A4 4468 Mallard
London and North Eastern Railway locomotive numbered 4468 "Mallard" is a Class A4 4-6-2 Pacific steam locomotive built at Doncaster Works, England in 1938. It is historically significant as the holder of the world speed record for steam locomotives at .
Russian locomotive class Ye
In 1944 the first steam engines of the Е series, which was given index "a" (U.S.), resulting in the designation of Еа. The numbers of locomotives built by ALCO began at #2001 and the Baldwin built locomotives at #2201. In September the same year, the first Baldwin built locomotive (Еа-2201) was sent to the pilot ring VNIIZhT which was tested until October. In the course of the tests, it was found that forcing the boiler to , a cutoff of 60% and at a speed of , the engine could develop of tractive effort. It was also found that the locomotive could achieve , which was a 20–25% increase compared to the World War I engines (). The improved performance was achieved through improved boiler and the use of mechanical stoker. The temperature of superheated steam was typically 572–644 °F (300–340 °C), and no more than 698 °F (370 °C).