The Stuttgart–Hattingen railway, also known as the Gäu Railway (German: Gäubahn, IPA: [ˈɡɔɪbaːn]) is a 148.5-kilometer-long railway in the southern part of the state of Baden-Württemberg in Germany, running from Stuttgart to Hattingen. The Royal Württemberg State Railways (Königlich Württembergischen Staats-Eisenbahnen or K.W.St.E.) and the Baden State Railways (Badische Staatseisenbahnen) constructed the majority of this line between the years 1866 and 1879. However, the line in its present form was not completed until the Deutsche Reichsbahn finished construction on the connection between Tuttlingen and Hattingen in 1934. Today the partially single-track, fully electrified line features the high-speed Intercity-Express (ICE) service, with its tilting train technology, traveling from Stut