The Adhesion Traction Wonder
The Bernina Line is one of the steepest adhesion railways in the world, achieving a breathtaking gradient of 70‰ (1 in 14) entirely without the use of cogwheels or rack systems. Operated by the Rhaetian Railway (RhB), the line was completed in 1910 and earned UNESCO World Heritage status in 2008 for its seamless integration of high-mountain engineering with wild alpine terrain.
Departing Chur or St. Moritz, the train climbs past Pontresina with staggering panoramic views of the Palü and Morteratsch Glaciers. At Alp Grüm (2,091 m), the train pauses on a shelf directly overlooking the turquoise Val Poschiavo, before twisting downward through horseshoe tunnels and corkscrews.
The Brusio Circular Viaduct
The crowning engineering jewel of the southern ramp is the 9-arch, 110-meter-long Brusio Spiral Viaduct. To lose elevation rapidly within a tight mountain canyon without exceeding the train's maximum 70‰ braking tolerance, Swiss engineers constructed a full 360-degree circle with a 70-meter radius, carrying the train under its own arches.