The Fontinettes hydraulic boat lift

Built between 1883 and 1887, the Fontinettes boat lift negotiated the Canal de Neufossé’s 13.13-metre level change between the Lys and Aa basins. This link between the North Sea and the large inland towns was crucial for trade, and the aim of the hydraulic lift was to reduce the two hours it took to climb the previous series of locks to twenty minutes. It worked like a gigantic pair of scales, with two enormous pistons each supporting a caisson containing the vessels. The pistons were encased in two cylinders filled with water and linked via a tube a central valve. By adding weight in the caisson opposite the lock’s upper reach then opening the valve, the cylinder supporting this caisson descended while the other rose. The lift was closed to traffic in 1967 and replaced by a new lock.