The Brenner Base Tunnel is a railway tunnel between Austria and Italy through the Alps with a total length of 64 km. The construction lot Tulfes-Pfons includes 38 km of tunnel excavation work. This lot consists of several structures such as the 9 km long Tulfes emergency tunnel. Such a service (non-public) tunnel does not necessarily require a tunnel lining system with two shells (primary shotcrete lining and secondary cast in place lining). Under certain boundary conditions a single shell lining approach can be applied. The required conditions and limitations for a single lining approach are reflected and a proposal for structural verification is provided. For verification approach a novel constitutive model for the shotcrete design is used.