The Brenner Base Tunnel - a new link through the Alps

15 After completion of the shell, the fixed track and the railway equipment are installed. The railway equipment consists of the signalling and safety systems, telecommunications and surveillance systems, ventilation and tunnel air conditioning, doors and gates, as well as all mechanical components and installations, including cables and controls. Tunnel technical equipment The tunnel lining and support structure are intended for a service lifetime of 200 years. The best quality building materials and working methods are therefore essential. Once the excavation and supporting works are completed, the tunnel is sealed and waterproofed. This is achieved by applying tunnel waterproof- ing, consisting of a supporting and draining mat (geotextile), and the actual seal (welded plastic sealing strips) to the interior surface of the tunnel. Next, the inner shells of concrete, cast in situ with a minimum thickness of 30 centimetres, are applied to the various underground cavity structures. Interior construction Securing of the tunnel arch with shotcrete, anchors, lattice arches and reinforcement mats.