The Deutsche Reichsbahn Gesellschaft's BR 05 (Baureihe, or series) was a German class of three express passenger steam locomotives of 4-6-4 wheel arrangement in the Whyte notation, or 2'C2' in the UIC notation used in continental Europe. They were part of the DRG's standard locomotive (Einheitslokomotive) series.
The locomotives did regular service in FD express passenger trains, e.g. FD 23 from Hamburg to Berlin. The design speed was 175 km/h (109 mph). In 1944, the streamline plates were removed. 05 003 had been rebuilt and lost the cab forward design.
05 001 and 05 002 (mainly) were used for test runs from 1935 to 1936. Most of these runs were made on complete journeys between Hamburg and Berlin. On June 7, 1935 the 05 002 made a top speed of 191.7 km/h (119.1 mph) near Berlin. The same engine made six more runs with more than 177 km/h (110 mph) with trains up to 254 t weight. On May 11, 1936 it set the world speed record for steam locomotives after reaching 200.4 km/h (124.5 mph) on the track between Hamburg and Berlin hauling a 197 t train. The engine power was more than 2,535 kW (3,400 ihp). This record was broken two years later by the British LNER Class A4 4468 Mallard engine.
On May 30, 1936 the 05 002 set an unbroken start stop speed record for steam locomotives: During the return run from a 190 km/h test Berlin-Hamburg it did the ~113 kilometres (70.1 miles) from Wittenberge to a signal stop before Berlin-Spandau in 48 min 32 s, meaning 139.4 km/h (86.66 mph) average between start and stop.
After World War II, the three engines came to the engine shop in Hamm, Westfalia. Since there were only three specimens of the 05, DB thought to scrap them. But then the engines were sent to Krauss-Maffei to be restored. 05 003 went into regular service in 1950, the other two in 1951. Boiler pressure was reduced to 16 bar (1600 kPa or 230 lbf/in²), hence the engines lost some of their old power. All three locomotives were used to haul express trains until 1958.
Mostly the 05 hauled the FD (long distance express) trains "Hanseat" and "Domspatz" on the run Hamburg - Cologne - Frankfurt. The regular top speed of the trains was 140 km/h. On this 703 km run the 05 operated trains did the longest run with steam traction in the DB network. July 1958 the 05 were replaced by the diesel-hydraulic DB class V 200.
05 001 went to the Verkehrsmuseum Nürnberg, where it can be seen streamlined with its original red livery. The other two locomotives were scrapped in 1960.