Approx. at km 44.7+00 there shall be an emergency stop (L=530 m) with relevant connection and ventilation tunnels, which shall be used to manage emergency situations in case of fire. The stop is connected to the outside by means of a carriageable tunnel that runs parallel to the line tunnel for approx. 5 km and subsequently comes out onto the Mules window (L=1720 m), which connects the work to the outside.
The tunnel system is completed by cross tunnels that, besides providing an escape between the pipes (one approx. every 333 m), also host the technical rooms and the fire-fighting tanks. For plant-engineering and hydraulic purposes, approx. every 2000 m there shall be vertical shafts for connection of the cross tunnels with the underlying service tunnel. Close to the Mules window entrance there shall also be an underground ventilation station, directly connected to the outside by means of a shaft (H=60 m).
From a geological point of view, the Brenner Base Tunnel develops across the main tectonic units forming the Alpine chain, with a maximum overburden of 1700 m. These units, which consist of several overlapping layers, are what remains of the collision between the European plate and the Adriatic (African) one; in the design area they form a dome, at the center of which it is possible to identify the Pennidic and Subpennidic units of the Tauern window, i.e. the deepest tectonic units that form the core of the Alps. Southward, the Brenner Base Tunnel crosses the fault zone that forms the Periadriatic Lineament, of regional relevance, which separates the Austroalpine basement from the Southern Alpine one.
The line tunnels show several applied typical sections, which vary based on both the excavation method (in part using traditional methods, but mainly with the TBM) and the number of tracks (close to the adjacent lot 'Underground Crossing of the Isarco' both tunnels become two-track and three-track).