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Origin and history

The Briare Canal Bridge is a metal structure designed to allow the lateral canal at the Loire River to cross the river without the risks of direct crossing. Prior to its construction, the vessels were required to travel through a one-kilometre-long Mantelot channel, which was subject to hazardous floods, stretches and currents. This passage, between the locks of Mantelot and the Combles, was painful and motivated the search for a safer solution.

A first masonry canal bridge project was considered in 1827 when the lateral canal was built, but abandoned due to the risk of dams in the event of flooding. The progress of metallurgy, particularly mild steel, had to be delayed to design a metal channel bridge offering a wide opening. The Briare site was chosen for its favourable gradient, allowing a free height gain.

The project, declared public utility in 1889 at a cost of 6.5 million francs, was entrusted to the engineers Léonce-Abel Mazoyer, Charles Sigault and Pierre Moreau. Mazoyer supervised the modernisation of the Roanne-Briare river network, including this canal bridge. Gustave Eiffel made the foundations and masonry (1890-1896), while Daydé & Pillé built the metal bowl. Inaugurated discreetly on 16 September 1896, it became the longest metal canal bridge in the world (662 m) until 2003.

The structure, entirely metallic, rests on 14 stone batteries delimiting 15 spans of 37 meters. It is lined with adorned sidewalks, streetlights and rostral columns, evoking the Alexander III Bridge. Decorative elements, such as rosers and chimeras, come from the Magnard (Fourchambault) and L. Gasne (Tusey) foundries. The canal, 6 meters wide, allows a draught of 1.80 meters.

The bridge-channel crossed not only the Loire, but also the old side canal of 1838 and the Trezée, via a last bridge-channel in masonry. Its construction was accompanied by a 14 km bib connecting the canals to the Cognardière. Ranked a Historical Monument in 1976, it symbolizes French river engineering and appears in works such as the Karatekas and Co (1973) series or a 1990 postal stamp.

Technical challenges, such as pioneering electrical lighting (1895) or the use of steel, made this work a reference. The Briarians, fearing floods, were distrustful, although recent rains may have distorted their observations. Today, there remains a major testimony of the industrial and river heritage of the Centre-Val de Loire region.

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