Record-Breaker. Sicily and Italian mainland crossing will span 3.7 kilometers.

The world’s longest suspension bridge, to span Sicily and the Italian mainland, will be built by a consortium led by Italy’s largest contactor. State-owned bridge concessionaire Stret-to di Messina SpA (SdM), Rome, hopes to sign the $4.7-billion design-build contract with the team led by Milan-based Impregilo SpA by year’s end.

The Impregilo team edged out a rival bid from another Italian-led consortium by cutting 12% from the owner’s base cost and some eight months from the construction schedule, according to SdM. The winning consortium will raise about $625 million in loans to help fund construction, to be repaid in phases throughout the project’s duration, says an SdM spokeswoman.

Once the contract is signed, the contractor’s designer, Cowi AS, Copenhagen, will have six months to prepare final designs for official approval, says Lars Jensen, Cowi deputy project manager. Four more months of detailed design will follow. That will lead to five years of construction.

With a 3.3-kilometer-long main span, the 3.7-km-long crossing over the Messina Strait will have a 60.4-meter-wide deck for six highway lanes, two service routes and two railway tracks. The deck will consist of three separate parallel steel box girders cross linked at 30-m intervals by secondary box girders. The 1.2-m-dia suspension cables will be in pairs.

Controlled by Impregilo, which holds a 45% share, the consortium also includes Spain’s Sacyr S.A., Italy’s Società Italiana Per Condotte D’Acqua SpA, Cooperativa Muratori & Cementisti-C.M.C. di Ravenna, Aci Consorzio Stabile and Ishikawajima-Harima Heavy Industries Co. Ltd., Japan.