At the beginning of July 2025 flash floods hit the US state of Texas – the clean-up efforts will still last for some months. Last year’s disastrous flood pointed out that Austria can also be affected anytime. Lainzer Tunnel and Atzenbrugger Tunnel, as parts of the highly frequented western route between Vienna and St. Pölten, were damaged. The existing infrastructure had not been sufficiently protected against heavy rain events and associated flood risks in its original layout – leading to water ingresses. This resulted in closures for weeks and months of this important traffic connection as well as damages amounting to millions of euros.

In future these costs can be prevented by the protection system now realized. Furthermore, the project considerably contributes to the operating safety, availability and resilience of a central section of the Austrian railway network.

This was enabled by the commitment of our colleagues in the Competence Centers:
✅ Railway Engineering – track engineering (track construction)
✅ Geotechnics & Natural Hazards
✅ Site Supervision

By order of ÖBB Infra AG our teams have developed an innovative concept how tunnel accesses can be systematically sealed off in case of floods to prevent critical damages in future.

The result: For the first time a mobile flood protection system was successfully and subsequently integrated into an existing infrastructure of ÖBB in a tunnel area with ballast-less track on a double-track high-performance route with track base plates and trafficable plates. The mobile flood protection system was specially designed for the tunnel portals of Lainzer Tunnel and Atzenbrugger Tunnel and implemented in the scope of a 25-day total closure in May 2025.

The developed solution is included into the ÖBB rules and standards as best-practice-example and enables a closure of the tunnel portals by ÖBB staff or the local fire brigade in case of floods or heavy rain events within a short time. The installation is manual, quick and without requiring heavy machines. The design offers a storage level of 1.35 m and thus reliably protects the tunnel cross section, the tracks, the line installations and other technical facilities against penetrating water.