Semmering Base Tunnel

The Semmering Base Tunnel is a railway tunnel under construction between Gloggnitz and Mürzzuschlag in Austria underneath the Semmering Pass. The existing route is 41 km in length and the Semmering Base Tunnel will be 27.3 km in length. The new route will offer time savings of up to 30 minutes, partly on account of the shorter route and partly on account of the higher speed limit.

Construction began on 25 April 2012 and the link is expected to enter operational service during 2026. The main benefit of the new tunnel will be increased ease of use for freight traffic. The gradients of the traditional routes requires the use of two locomotives; the reduced gradient of the new link will enable the transit of freight traffic using just one locomotive. The Semmering Base Tunnel and the Koralm Railway in combination will enable freight transit across the whole southern line with just one locomotive.