Brusio spiral viaduct

The Brusio spiral viaduct is the moment on the Bernina line when the train seems to chase its own tail. Just south of the village of Brusio, in the Val Poschiavo, the railway makes a full 360-degree loop and passes beneath itself, climbing on a curved stone viaduct of nine arches, each spanning 10 metres, set on a radius of 70 metres. The bridge alone is about 110 metres long, or nearly 143 including its approach embankment, and it crosses the valley floor between 7 and 17 metres up.

It exists because the engineers refused to use a rack. The Bernina Railway was designed as an adhesion line, fit for freight as well as passengers, with a maximum gradient of 7 percent, and between Brusio and Campocologno the valley drops faster than that. Several solutions were drawn up in 1906, among them an S-shaped embankment and an eight-arch bridge; a spiral tunnel was also considered but the geology argued against it. The open loop that returns under its own viaduct first appears in a plan of October 1906, perhaps because it needed less land. Work started in March 1907, and the section from Tirano to Poschiavo opened on 1 July 1908.

The Rhaetian Railway has owned and run the line since 1943. In 2008 the Albula and Bernina lines became a UNESCO World Heritage Site, with the viaduct among its best-known features. It has had to be defended against the mountain: after a large rockfall above it in December 2008 closed the line for 111 days, a protective dam was built, and in 2011 the viaduct was thoroughly restored, with a waterproof concrete trough laid into the top of the masonry and the deck widened slightly. The loop can be enjoyed from the train, including the Bernina Express, or from the ground at the edge of Brusio watching the trains curl around the arches and pass beneath them.

Getting there

The viaduct is on the southern edge of Brusio, about 600 metres from Brusio station on the Bernina line, which runs from St. Moritz down to Tirano in Italy. The nearest Swiss city is Chur, about 80 km away; the nearest Italian town of size is Sondrio, about 22 km away. The nearest airports are Bergamo Il Caravaggio (BGY), about 73 km away, and Lugano (LUG), about 98 km away.