From ford to bridge
Cité épiscopale d’Albi
From the hills of the Lozère in the Languedoc-Roussilon, through the rapids of the Saut de Sabo, the river Tarn arrives at the plain, passing through a series of meanders which transform it into a peaceful river. Nonetheless, the banks remain deep and steep-sided until it meets the river Caussels after which its banks become less abrupt.
For a long time the ford close to the site of the Pont-vieux was one of the only crossing points on this river’s rugged course.
This privileged spot was probably the original site of the future city of Albi.
In the Middle Ages, technical and financial constraints meant that the location of a bridge’s supports was decided by natural factors. This explains the variable spacing of the arches.
It was not until the 18th century that it became possible to overcome the constraints of a site and build bridges with uniform arches, conforming to an abstract artistic conception.
During the works to redress and enlarge the carriageway it was therefore also possible to modify the supports.
The cutwaters of the two pillars closest to the left bank were extended downstream. A box caisson was built using stakes and sheet piling into which was poured a mixture of pebbles and a mortar made of sand and chalk.
Beams were then placed upon this foundation and provided the base for the brick work which was joined to, and followed the contour of, the columns. In the remaining pillars the brick arches rested directly on the cutwaters.
On the upstream side a completely different solution was found. The upstream ends of the cutwaters were reshaped, conserving the triangular form of the the lower section but giving a new form to the upper part. As can be seen today, these modified cutwaters were then used to support lowered brick corbel arches.
These works considerably altered the structure and appearance of the Pont-vieux and the new brick façade gave the bridge an the appearance more in keeping with its surroundings.
