The Deutsche Reichsbahn-Gesellschaft's BR 01 steam locomotives were the first standardised (Einheitsdampflokomotive) steam express passenger locomotives built by the unified German railway system. They were of 4-6-2 "Pacific" wheel arrangement in the Whyte notation, or 2′C1′ h2 in the UIC classification. The idea of standardisation was that it would reduce maintenance costs; i.e. if a BR 01 whose engine shop was in, say, Berlin broke down in Dresden, instead of having to ship the necessary part from Berlin and take the locomotive out of service, a part from the Dresden shop could be used as all of the engines, parts, and workings were exactly the same and produced nationwide. Thus it was a "standard" product for engine shops.