Nelson Mandela Footbridge

The Nelson Mandela Bridge crosses both the Oise River and the railway lines in Creil. The structure creates a much-needed link between the communities of the Creil municipal association.

The bridge is a key element in the large scale civic development strategy and intends to create an "urban landmark", which connects an uninterrupted pedestrian and cyclist path between the Plateau district on the left bank of the Oise and the Gournay neighborhood on the right bank in active urban renewal. At the core of the crossing is the link with the Park of Saint Maurice Island pathway and the future Fichet Place, making the bridge the unifying element and the symbolic union between the two parts of the city.

The structural of the bridge responds to the architectural and landscape requirements of the site as well as the constraints of a major river crossing. With great slenderness, the suspended structure effectively responds to these requirements by avoiding a pile in the Oise. The design with a single mast on the island reflects the asymmetry of the site with the refined silhouette of the mast integrating with the verticality o the vegetation of the island while creating a strong, elegant signal from the urban bank of the place Fichet.

The suspended structure and ist intersecting hanger cables permit the thrilling slenderness of the design: the total length is spanned by a thin concrete deck slab with less than 30cm thickness. The structure scheme also reduced the construction impact on the river traffic: the cables were pulled on a rope and installed in one night, and the deck was crane lifted in small prefabricated elements of 4m in length.

The bridge is 100m long, with a single 80m span over the Oise River. The mast is 28m tall, consisting of structural steel sections welded from curved metal plates, and creates an inverted V on the Island's shore. A pair of cables stays the mast to ist anchorages on the island. A second pair of suspension cables crosses the river connecting the top of the mast with the abutment on the urban riverbank. The concrete deck is suspended to a fine mesh of diagonal tension rods. On the right bank, a 100m concrete ramp supported by tubular columns aligns with the bridge deck, creating a continuous and slender ribbon of 200 m length.

On the island, access to the bridge is provided by a 120 m long light steel ramp aligned with the Oise River, and a staircase, and both covered with wooden decking.

Careful structural analysis has led to a final bridge which is visually consistent with the original project image. The inherently efficient structural system and optimized structural elements highlight the slenderness of the
structure.