Siena, Italy is home to the world’s first major footbridge built from Outokumpu’s LDX 2101® duplex stainless steel. The project is the result of successful interplay between an enlightened design engineer, farsighted community leaders, Outokumpu’s product development and an advanced service concept. The City of Siena in Tuscany, Italy had trusted Ing. Pistoletti with several bridge designs before when they turned to him again to design a footbridge over a busy motorway in the suburb of Ruffolo. Ing. Pistoletti and his engineering firm SETECO went to work on an all-stainless steel, cable-stayed bridge. The process took a new turn when Outokumpu’s Italian marketing arm Outokumpu SpA introduced SETECO to a new material: LDX 2101® duplex stainless steel developed by Outokumpu. LDX 2101® is a lean duplex grade that provides the excellent properties of duplex stainless steels, but has a nickel content of only 1.5%. The grade is suitable for load-bearing structures where moderate corrosion resistance is adequate such as in Siena, an inland city with low pollution levels. Outokumpu brought more value into the project with its “lego” service concept, successfully used in a large number of bridge construction projects worldwide: plates are hot rolled and ground for the purpose, they are cut and bent into customized bridge components, and the edges are prepared for welding. The components are joined at the site. Outokumpu also provided technical assistance for the builders. The “lego” assembly helped minimize the impact of the construction on the surroundings.
