Swing Span

Swing span bridges open by rotating the movable span about a vertical axis so that the span is parallel with the navigation channels. When in a closed position (closed to marine traffic), the span is supported by three piers. The pivot pier supports the dead weight of the swing span itself. When the span is not completely closed, its entire weight rests on the pivot pier. The rest piers stabilize the span and along with the pivot pier, support the live load (the weight of vehicular traffic) as it passes over the bridge.