Martin Herrenknecht, who turned 70, founded the company in 1977. More than 2,000 guests – from politics, the customers, the tunnel industry and the company workforce – were invited to the gala in the Baden-Arena in Offenburg, Germany, to celebrate.
"Martin Herrenknecht is one of the greatest entrepreneurs of our country, we can learn much from his positive thinking and attitude to life," said Gerhard Schroeder, former German chancellor.
