The team delivering the latest section of a 64km subterranean link between Austria and Italy has celebrated simultaneous breakthroughs on its two tubes.
The H53 consortium, featuring Vienna-based contractor Porr and Swiss outfit Marti, hailed the “significant milestone” on the Brenner Base Tunnel.
Linking Innsbruck and Fortezza, the crossing will become the world’s longest underground rail connection.
Construction began in Italy in 2007, ramping up in Austria two years later.
The recently completed section, a 25km stretch between Pfons and Brenner, was awarded as Lot H53, with blasting excavation beginning in March 2024.
Breakthrough has now been achieved in both the western and eastern tubes, with Austrian crews meeting their Italian counterparts 1,408m beneath the Geigenspitze.
Porr chief executive Karl-Heinz Strauss said: “A milestone moment like this is the result of dedication, professional expertise and team spirit.
“Our employees have managed something extraordinary under challenging conditions. Together with all project stakeholders, we’ve already achieved an enormous amount, even if important tasks still lie ahead of us.
“Today we’re celebrating this success and looking back with pride on our own achievement”.
Crews worked their way through central gneiss – a particularly hard rock from the innermost and deepest geological unit of the Tauern Window.
Six to eight employees worked around the clock on the latest section in a four-shift operation. Precise coordination of works was required for both tubes to reach the national border almost simultaneously.
Tunnel boring machines Olga and Wilma will now continue driving the main tunnel tubes towards Innsbruck.
The Brenner Base Tunnel is designed to create an important north-south rail link through the Alps and make a significant contribution to shifting transport from road to rail.
It consists of two parallel main tubes between 40m and 70m apart. Each will be equipped with a single track and linked every 333m by cross passages that can serve as escape routes.
A third exploratory tunnel is being created beneath the two main tubes to provide information about the rock structure and to investigate the geological conditions. In operation, this will serve as a service tunnel for water drainage and maintenance activities.