As part of the Stuttgart 21 project, a new long-distance and regional railway station is being built at the airport, including a tunnel to connect it to the new Stuttgart-Ulm line. The underground station Flughafen/Messe will have a length of 400 m and – just like the two single-track, 1.8 km long tubes of the airport tunnel – will be constructed using mining methods. At the beginning of 2020, SÜLZLE Nutzeisen supplied about 100 tons of steel girders and steel structures for pipe and line suspensions for this construction project. The prefabricated steel constructions for the underground long-distance railway station were installed by Markgraf Schweißfachbetrieb GmbH and the steel girders were professionally welded.