Pfaffenbergbrücke, Railway arch bridge in Obervellach, Austria.

The Pfaffenbergbrücke is a two-track railway bridge of the Tauern Railway in the municipality of Reißeck, Carinthia, near Obervellach. Its 377 m long, 10 m wide reinforced concrete deck rests largely on a single arch spanning 200 m, fixed in the abutment foundations with a rise of 50 m. The arch crosses a side valley of the Mölltal at a maximum height of 100 m.

The bridge was completed in 1971 during the realignment of the Tauern Railway, replacing an older steel bridge that crossed the side valley further inside. Its 200 m reinforced-concrete arch made it, at the time, the largest railway-used concrete arch span in Europe. The arch was built on a free-standing falsework with the cross-section added in stages.

The bridge carries the double-track Tauern Railway over a side valley of the Mölltal at a maximum height of 100 m. About 1 km uphill on the same line stands the Falkensteinbrücke, so passengers crossing the Pfaffenbergbrücke see one large concrete arch bridge after another.

The bridge is visible from the railway line and can be observed from Tauern Railway trains, especially from certain seat positions in the train. Visitors exploring the area should know that direct access underneath or on top of the bridge is not permitted, as it is only for train traffic.

The bridge was an engineering achievement of its time, using techniques that pushed the limits of what was possible then. Calculating and planning such long spans without intermediate supports in a mountain valley was a complex challenge that engineers in the 1970s had to solve.