The Solkan Rail Bridge

Photo: Miško Kranjec

The central arch spans 85 m, making the Solkan Bridge the longest stone railway bridge in the world.

The Solkan viaduct was built in 1905 as part of the railway line between Vienna and Trieste. It is remarkable for the elegance and lightness of its stone structure, which spans the river Soča in a rainbow-like arc. Blown up during the First World War and subsequently rebuilt, the viaduct survived the Second World War relatively unscathed. 

The Bohinj Line  is a 158-kilometre section of the 717-kilometre Prague–Jesenice–Gorizia–Trieste railway line. It was built between 1900 and 1906 to connect central Europe with the Adriatic coast.

Structures on the Bohinj Line include five tunnels and 65 bridges. The Bohinj Tunnel is still today the longest tunnel entirely in Slovenia. Another record-breaking structure is the "stone giant" of the Bohinj Line – the viaduct over the Soča at Solkan, whose stone arch has a span of 85 metres. It was built in segments using blocks of cut stone that gradually completed the two halves of the arch. Most of the blocks weighed around 800 kg, although some of the largest ones weighed up to 2,100 kg. The great arch is built from a total of 4,533 stone blocks of shelly limestone from the Cava Romana quarry at Aurisina. The blocks are joined together by a cement mortar consisting of Portland cement from Split and washed sand from the Soča. Thanks to this construction technique – the innovative use of an arch of cut stone – the Solkan viaduct is still the largest stone railway bridge in the world. The railway line crosses the river at a height of 36 metres. 

Text by Tanja Glogovčan