Underground and Metropolitan Railways
IApart from extending the above-ground traffic network, Trapp have also been involved in underground and municipal railway construction from early on. Large-scale projects in Berlin, Duisburg, Dortmund and Munich bear Trapp's signature. Four sections were constructed in Berlin from 1966 to 1970. A fifth, job G 14, was completed in a joint venture with Trapp in charge in the summer of 1971. This construction project in Berlin came to Euro 50 mill, at that time. In Munich Trapp were involved in the largest underground railway contract in Germany 25 years ago costing a grand total of Euro 100 mill. Then there was a contract in Dortmund for almost Euro 20 mill.
Additionally Trapp have participated in extending a partial section of the Duisburg underground railway in Meiderich as well as the Bonn underground railway system.
In Berlin Trapp have collaborated in redevelopment of the Oberbaum Bridge, the Weidendammer Bridge, the Warschauer Strasse underground railway station and in renovating the Friedrichstrasse railway station.
Constructed from 1997 to 2001 is the new Rhine/Main section for ICE, the rapid transit train route, largely following the A3 motorway between Cologne and Frankfurt. Job B, which Trapp were involved in, had a scope of Euro 650 million.