Planned Undersea Tunnel Divides Germans, Danish $7.2B, 12.5-mile endeavor would be Europe's largest infrastructure project By Matt Cantor, Newser User Posted Dec 30, 2011 9:29 AM CST 5 comments Comments German Chancellor Angela Merkel. (AP Photo/Markus Schreiber) (Newser) – Denmark is preparing for the largest infrastructure project in Europe: a 12.5-mile tunnel to Germany under the Baltic Sea. But the $7.2 billion project, which would be among the world's longest immersed tunnels, has sparked tensions with Germans who are dubious about its usefulness, Der Spiegel reports. With a cost-benefit ratio of 1:1.25, "The World Bank would say that this is a marginal project," says a German engineer. "It was clear right from the start that the interests of the construction industry are behind this." The engineer, Hendrick Kerlen, has investigated the logistics of the project and questions the planners' decisions. The numbers "don't add up at all," he says. Indeed, Germans have taken to calling the project, which would link the Danish island of Lolland to Fehmarn in Germany, "Fehmarn 21"—a nickname that ties it to other questionable projects. Germans simply feel they don't need the tunnel, says an opponent. Danes, meanwhile, want to build a stronger connection with Europe; now, the project is in their hands. Click through for more on the debate.