The Briare canal bridge
The canal that runs parallel to the Loire crosses the Loire at Briare on a Canal bridge that was built between 1890 and 1896.
Between the 14th and 19th centuries, large vessels always used the Loire, but the irregulaty of the rivers flow and bed often placed insuperable difficulties in the way of the companies.
The decision to build the Briare Canal was taken in 1605 by Henri IV, as part of his policy of achieving national economic unification. The canal was opened in 1642 and joined the Loire and Seine basins at Montargis via the Loing valley. This was Europe’s first watershed canal.
The Loire lateral canal (1822-1838) extends the Brare canal south as far as Digoin. It crosses the Loire at Briare by means of a canal bridge (designed by the famous engineer Mazoyer), which was built 58 years after those at Guétin and Digoin. The metal-lined water channel is the longest in the world (662,69 metres) and is supported by 15 granite piers (designed by Eiffel). These carry the same load whether or not there is a barge crossing the bridge (Archimedes principle).
Construction was partly undertaken by Eiffel’s company and took place between 1890 and 1896, In 1896 the pounds connecting the canal bridge to the Briare canal and the Loire lateral canal were filled with water. The canal bridge was opened to traffic at 8 o’clock in the morning of 16 September 1896.
The canal bridge in figures:
- Over the Loire the structure at a height of 11 metres and 600 metres long,
- The total length of the bridge, including where it crosses the old canal is 662.69 metres.
- It has 14 piers, 2 abutments and 15 spans of 40 metres. The canal bridge is fixed over the 8th pier and expands on both sides of this.
- The frame of the canal bridge consists of two beams 3.4 metres in height which are 7.26 apart from each other. These beams are connected by a U-shaped metal sheet.
- Two 2.5 metre footpaths have been built on top of the beams.
- The canal bridge has a total width of 11.50 metres and an effective width of 6.20 metres.
- The water in the bridge channel is 2.20 metres deep.
- The metal part of the structure weighs 3053 tonnes and the entire structure weighs 13,680 tonnes.
- The total painted surface area of the bridge is 42,000 m2. Repainting requires a minimum of 2 tonnes of red lead and almost 15 tonnes of paint.
Find out more :
- The Briare canal-bridge seen from different angles (Format pdf - 58.4 kb - 29/02/2008)
- Cut-away diagram of the canal bridge (Format pdf - 57.2 kb - 29/02/2008)