Furka Cogwheel Steam Railway, Heritage steam railway in Obergoms, Switzerland

The Furka Cogwheel Steam Railway runs 18 km from Realp (1,538 m) in Uri to Oberwald (1,366 m) in Valais, climbing to the Furka station at 2,160 m. It uses an Abt rack system on gradients up to 118 ‰ and a 1,874 m summit tunnel without rack. Steam trains with blue passenger cars cross the stone Steffenbach viaduct.

Construction of the cogwheel line over the Furka Pass began in 1911 under the Brig-Furka-Disentis-Bahn and halted in 1915; after that company's 1923 bankruptcy, the Furka-Oberalp-Bahn resumed work and opened the line in 1925. It was electrified in 1942. The mountain section closed for the winter of 1981 and was replaced by the Furka Base Tunnel in 1982; volunteers founded the Verein Furka-Bergstrecke in 1983 and the DFB company in 1985, and steam services returned from 1992, reaching Oberwald in 2010.

The line is run almost entirely by unpaid volunteers, called "Fronarbeiter", from several countries who give their labour through a support association for construction, maintenance and operation. The heritage vehicles were bought from various Swiss narrow-gauge railways and restored. Since 2012 a through steam special, the Swiss Alps Classic Express, has run at least once each summer from St. Moritz to Zermatt.

The line runs only in the snow-free season, roughly June to October, and is closed for about seven months each winter. Before reopening, volunteers clear snow and rebuild the folding Steffenbach bridge. The route climbs from Realp at 1,538 m to the Furka station at 2,160 m, so expect cold and changeable weather even in summer.

The line's rack over the Furka Pass road is retractable: it lifts together with the level-crossing barriers, actuated by radio from the locomotives. In a forested nature reserve, sprinklers switch on before and after each train, cascading up or down the section to save water drawn near the summit.