RSRG is playing a major role in Austria: Following the successful fit-out of the Koralm Tunnel, the Group is now taking on the Semmering project.
When ÖBB celebrated the first official journey through the Koralm Tunnel in December 2025, representatives of RSRG were also there – already thinking ahead to “their” next major Southern Line project.
With a total length of 470 kilometres, extending from Austria’s northern to its southern border, passing through four federal states and linking three state capitals, ÖBB’s Southern Line is one of the largest and most spectacular infrastructure projects ever undertaken in Austria. As part of the Baltic–Adriatic Corridor, which in the medium term will connect the Baltic Sea with the Mediterranean by land, this impressive construction project will also provide invaluable links to emerging economic regions and major seaports.
ÖBB-Infrastruktur AG is working on more than 100 projects along this corridor to improve mobility for the 3.5 million people living in its catchment area and provide them with even easier and more affordable access to goods from around the world. Two of the largest projects are the Semmering Base Tunnel between Lower Austria and Styria and the Koralm Railway, which connects Graz and Klagenfurt beneath the Koralpe mountain range.
Around 37 million passengers and 22 million tonnes of freight are already transported along the Southern Railway routes every year. In future, the upgraded high-performance railway line will enable them to reach their destinations more quickly and sustainably. Once the new major tunnel enters service, the operational and logistical restrictions associated with journeys across the Semmering will be a thing of the past, and the Semmering will no longer constitute a time-consuming and costly obstacle. The new Koralm Railway route, meanwhile, bypasses the narrow Mur Valley and the steep Neumarkt Pass.
RSRG playing a leading role
The Rhomberg Sersa Rail Group has played and continues to play a critical role in both the Koralm and Semmering Base Tunnels. Together with joint venture partner PORR, the rail technology specialist installed the railway systems and electrical and mechanical equipment in the Koralm Tunnel – at 33 kilometres, the sixth-longest railway tunnel in the world – and ensured that it was ready for operation in time for the timetable change in December 2025. The rail technology experts and partners installed almost 66 kilometres of slab track and were responsible for all civil engineering works through to commissioning.
The joint venture team is currently delivering the same scope of work in the planning and implementation of the railway systems fit-out for the Semmering Base Tunnel. By the planned commissioning date in December 2029, the partners will have contributed to the timely opening of the line on practically the same scale as at the Koralm Tunnel.
“Winning the contract for the railway systems fit-out and equipment of the Semmering Base Tunnel is a wonderful endorsement of the work we carried out in the Koralm Tunnel,” says Gernot Gassner, Managing Director, Project Business, at the Rhomberg Sersa Rail Group. “Here too, we will once again be delighted to contribute our expertise as a full-service provider and continue to build on the experience gained from numerous successfully completed projects.”
