The renovation and lengthening of the locks at Méricourt has several aims:  to restore the locks to their original width, to guarantee the future stability and reliability of the structures in normal and extreme situations, and to lengthen lock No. 1 from the downstream side in order to be able to accommodate 180-metre long convoys. In order to guarantee service continuity, navigation on the Seine will be maintained throughout the works, with at least one 185-metre lock remaining operational at all times.