The Austrian Federal Railways contracted the planning of the proposed Semmering Base Tunnel's route to a consortium of Werner Consult and Witrisal consortium to conduct the route planning for the tunnel. Separately, Gruner AG was also involved in the design for the new twin-tube tunnels; this work included its aerodynamics and environmental control, including operational and emergency ventilation systems. Soil mechanical and geotechnical consulting services at the intermediate sites at Fröschnitzgraben and Grautschenhof by INSITU Geotechnics.