The Brusio Spiral Viaduct is a single-track nine-arched stone spiral railway viaduct located in Brusio, in the Canton of Graubünden, Switzerland. Like most spiral tracks, the spiral viaduct was built to permit trains to get elevation in a relatively short distance.
The Brusio Spiral Viaduct is 110 meters long, has a horizontal radius of curvature of 70 meters, a longitudinal slope of 7%, and is made up of nine spans, every 10 meters in length. The viaduct lifts the train by 20 meters. The spiral viaduct forms part of the Bernina Railway section between Brusio and Campascio, and is about 55 KM from St. Moritz. Spiral curves maximize elevation instead of switchbacks, avoiding the inconveniences that come with switchbacks. The construction of this building utilized local materials whenever possible.
The stone-built viaduct was opened on 1 July 1908, upon the opening of the Tirano–Poschiavo section of the Bernina Railway. In 1943, the entire railway company was taken over by the Rhaetian Railway, which still owns and uses 40 seconds after passing under the viaduct near Brusio, BERNINA EXPRESS 960 Tirano-Davos with Allegra trainset ABe 8/12 3505 “Giovanni Segantini” and 6 panorama coaches are completing the Brusio Spiral Viaduct.
In the center, is the temporary labyrinth, an installation for the 100th anniversary of the Bernina line. As part of the opening of the Bernina Railway between Tirano and Poschiavo on 1 July 1908, the viaduct was completed. The Rhaetian Railway absorbed the entire Bernina Railway in 1943; this company continues to operate services across the spiral viaduct to this day. Besides facilitating local trade, the spiral viaduct facilitates tourism as well.
UNESCO has recognized this route, including the spiral viaduct, as a World Heritage Site since 2008.