The exterior diamond lattice of steel provides form and function. With such a load-bearing exoskeleton and a solid central core, no interior columns are needed providing large open interior spaces.
These three self-anchored suspension bridges span the Allegheny River in downtown Pittsburgh. From front to back they are the Roberto Clemente Bridge, the Andy Warhol Bridge and the Rachel Carson Bridge.
Built from 1924 to 1928, they are the only trio of nearly identical bridges, as well as the first self-anchored suspension spans, built in the United States.