With a total weight of 548,3t and a power of 6.290 HP (@48 km/h) the Union Pacific Railroad (UP) class 4000 locomotives (well know as "Big Boy") is one of the most powerful steam locomotives on the world. The American Locomotive Company (ALCO) built a total of 25 units between 1941 and 1944. At a maximum speed of 112 km/h (70mph) the Big boy is also the fastest articulated steam engine at all.
In 1949 the Deutsche Bundesbahn had ordered 105 locos of Class 23 steam locomotives to replace old-fashioned Prussian P8 locos. The 2 cylinder locos developed 1785 HP and reached a maximum speed of 110 km/h. They were used for passenger service, sometimes also for fast trains. Last 23 quitted service in 1975, but eight locos can be found at railroad museums in Germany and the Nederlands.
The BR 01 had been the first type of the Einheitslok-Progamm of the Deutsche Reichsbahn-Gesellschaft (DRG). Starting in 1925 the DRG ordered 231 locos. The 2 cylinder 01 reached a maximum speed of 120 (later 130 km/h). Both German Railways DB and DR needed the 01 after 2nd World War so the modernized 50 (DB) and 35 (DR) locos of BR 01 e.g. with new boilers. Nevertheless original 01 stayed in service until the early 1970s.
Steam locomotive universal sound 2 - 4 cylinders
suitable for German Baureihe 64 and similar loco types and sizes