Herrenknecht AG is a globally successful family business with 5000 employees and the market leader, not only for tunnel boring machines. Since the founding of Herrenknecht GmbH in 1977 by – as described aptly in the company chronicle – “namesake, driving force and CEO” Dr.-Ing. E. h. Martin Herrenknecht, the company has developed dynamically and convinced again and again with technically sophisticated solutions to problems in underground construction. Meanwhile, Martin-Devid Herrenknecht, engineer and one of three children, has joined the company. Rarely does one have the opportunity to meet both father and son for a very personal interview with fascinating statements on the market, technologies and the future of tunnel construction.