About the project
At the time of construction the viaduct was the fifth longest road crossing in the world. The central 848m long section, which crosses a busy shipping lane, includes the world’’s longest unsupported welded steel box girder span - some 300m in total. Cable-supported spans were ruled out because of the risk of an aircraft strike. The bridge was designed by American consultant HNTB, but the terms of the £31 million British loan stipulated that the money could only be spent in the UK or Brazil. As a result the designs had to be revised to account for the difference between the grades of UK and UK steel.
The most demanding part of the Rio Niteroi project was the erection of the steel girders. Although they form just a few spans of the bridge, the short construction programme and challenging site meant that the usual techniques for this type of span could not be applied.