Future-proof fire detection for the Seelisberg Tunnel

Modernisation of a critical infrastructure during ongoing operations

The Seelisberg Tunnel is a key element of the A2 motorway and one of Switzerland's most important north-south transport connections. With a length of more than nine kilometres, twin bores, a high volume of traffic and a complex ventilation infrastructure, particularly stringent requirements apply to fire protection. The modernisation had to be carried out during ongoing operation and was not allowed to impair the availability or safety of the tunnel. Securiton planned and implemented the phased renewal of the fire alarm system with a clear focus on operational reliability, redundancy and minimal impact on ongoing traffic.

High-performance fire detection over the entire length of the tunnel

As part of the modernisation, a total of six SecuriFire 3000 fire alarm control panels were installed. These are responsible for central control, monitoring and alarm raising in the ventilation control centres for both tunnel bores and the connected technical areas. The new system architecture enables clear zoning and precise localisation of events via an interface to the operations control centre.

322 multi-sensors and 85 scattered-light smoke detectors are distributed in the connected technical buildings for the early detection of fires. Around 1,900 metres of sensor cable were used in the partially modernised traffic area. These enable continuous temperature monitoring along the tunnel infrastructure and are particularly suitable for long, hard-to-reach areas. The combination of state-of-the-art control panel and linear detection ensures that fire incidents are quickly detected and pinpointed with precision.

Integration, redundancy and long-term operational reliability

The modernised fire alarm system was designed in such a way that it can be seamlessly integrated into the existing tunnel infrastructure and the operator’s operational processes. Redundant system components and a clear structure ensure high availability even during maintenance work or in the event of faults. At the same time, the new solution enables easy extension and adaptation to future requirements. Implementation took place in stages and in close coordination with the operator in order to minimise traffic restrictions.

The modernisation of the fire alarm system in the Seelisberg Tunnel shows how challenging infrastructure projects can be successfully implemented during ongoing operations. The new SecuriFire solution provides the tunnel with high-performance, reliable and future-proof fire detection. Securiton not only provides the technology, but also the experience of modernising critical systems safely and efficiently.