The longest floating bridge in the world

The world's longest floating bridge is now under construction in Seattle – a masterpiece of engineering and logistics. Munich Re, with its wealth of expertise, is involved in insuring the project.


Even for experienced bridge builders, floating bridges without foundations or piers are extremely challenging. For over 50 years, the longest floating bridge in the world has connected downtown Seattle with the northern communities on the other side of Lake Washington. A large number of commuters use the bridge every morning to travel to work in the city centre or in the fast-growing suburbs. Almost 100,000 employees work at just one location, the Microsoft headquarters in the town of Redmond, to the east of Lake Washington. Every day, up to 115,000 vehicles thunder across the 2.3 km bridge, which was originally designed for a maximum load of just 65,000 vehicles. Until now, the old bridge has withstood severe storms, the waves, and, in 2001, the last major earthquake. But it has fallen into a state of disrepair, its age and the impact from the steadily increasing volume of heavy-duty traffic and the enormous axle-loads involved are clearly visible in many places. The weather conditions are also taking their toll on the bridge. The concrete structure is now porous, allowing water to penetrate, and the steel girders are rusting at an alarming rate.

The new bridge will be more resistant to earthquakes and storms

A debate about a replacement bridge, the cost and design of a new bridge, was triggered in Seattle by the 2001 earthquake. The issue was only settled ten years later: A new floating bridge directly alongside the Governor Albert D. Rosellini Bridge, commissioned by the State of Washington, has been under construction since October 2011. The new bridge is not only meant to be higher and substantially wider, with six lanes and cycle and pedestrian paths, but more importantly, it will also be safer. It is to be a prestige project that pushes bridge construction to the limits of what is technically feasible. Since long floating bridges are only rarely built anywhere in the world, a partner with a wealth of experience and expertise was required on the reinsurance side, one who would understand the risks attached to such an ambitious project and be in a position to provide the relevant reinsurance cover. The experts from Munich Re Engineering, many of them engineers with extensive experience on construction sites of major global projects, stepped up to the challenge and developed a reinsurance solution tailored to meeting the complex risks of the different manufacturing areas.