A Rhomberg Sersa Rail Group and Porr joint venture is progressing the technical fit-out of the Semmering Base Tunnel, in preparation for its opening in 2029.
The team, appointed by ÖBB Infrastruktur, is equipping the tunnel with telecommunications, high-voltage installations, distribution boards, lighting and escape route signage, as well as mechanical systems for air conditioning, ventilation and firefighting water supply.
The works also include 55km of slab track, connections to ballasted track, noise protection, substructure and steelwork, earthworks, concrete and ceiling works, and turnouts and ballasted track at the two portals in the west and east.
Work is currently being undertaken on the Styrian side and from mid next year the focus will increasingly shift to the Gloggnitz portal on the Lower Austrian side of the tunnel.
The fit-out, which follows the final tunnel breakthrough in December 2024, involves the installation of around 1,000km of cables, more than 3,200 lights, 55km of illuminated handrail, approximately 13,500 signs, and 10,600 5m-long track support slabs.
Siemens is supplying the control and telecontrol systems, automation and protection technology. Sixty-nine SICAM A8000 control-system cabinets form the tunnel’s central nervous system, automating 56 cross-passages and integrating around 25,000 hardware signals.
With centralised and decentralised control, the system ensures maximum efficiency and safety for all integrated systems, such as power supply and ventilation.
The installed 24kV blueGIS switchgear, the first F-gas-free switchgear in an Austrian tunnel, provides environmentally responsible medium-voltage power distribution. Together with SIPROTEC 5 protection relays and supervisory computers, this allows complex technical systems to be monitored transparently, enabling faults to be detected early and processes to be controlled efficiently.
The 27.3km twin-bore Semmering Base Tunnel between Gloggnitz and Mürzzuschlag will link the two federal states of Lower Austria and Styria.
The tunnel will allow trains to travel at up to 230km/h and cut journey times by 30 minutes. Freight transport will also benefit from the project along the strategically important Baltic–Adriatic EU Corridor.
Together with the Koralm Railway, the Semmering Base Tunnel will create a low-gradient route on the Vienna–Villach Southern Line, meaning heavy freight trains will no longer require two locomotives.
