Historic Boat Lifts of the Canal du Centre, La Louvière

Between Houdeng-Goegnies and Thieu, on the western edge of the Belgian Centre coalfield, an old canal climbs a slope that no chain of locks could reasonably handle: over a stretch of about seven kilometres the water level changes by some 66 metres. The answer, built between 1885 and 1917, was a staircase of four hydraulic boat lifts. The first, at Houdeng-Goegnies, lifts boats 15.40 metres and went into service in 1888; the other three, at Houdeng-Aimeries, Strépy-Bracquegnies and Thieu, each rise 16.93 metres and were finished in 1917, though the First World War delayed their formal inauguration until 1919. They are the only lifts of their kind from that era still in working order, and since 1998 they have been a UNESCO World Heritage Site.

The principle is as elegant as a pair of kitchen scales. Each lift has two great iron troughs, or caissons, standing side by side, each resting on a single enormous piston that plunges into a water-filled cylinder. The two cylinders are connected, so one caisson can only rise if the other sinks. A boat floating in a caisson displaces exactly its own weight of water, which means a loaded barge adds nothing to the balance; to set the machine moving, the operators simply let an extra 30 centimetres or so of water into the upper trough, and its added weight of roughly 74 tonnes drives it down and pushes its twin up. The design came from the British engineer Edwin Clark, who had already built a similar lift at Anderton in Cheshire; the Belgian contract went to the Cockerill works at Seraing, with Jean Kraft as chief engineer.

The motive behind all this ironwork was coal. At the end of the nineteenth century the mines of the Centre basin were losing ground to French and German competitors, and a canal able to take 300-tonne barges of the Freycinet gauge all the way between the Meuse and Scheldt basins was meant to keep them in the game. What survives today is a whole working landscape rather than four isolated machines: the lifts themselves with their riveted lattice towers and glazed control cabins, the engine house at Strépy-Bracquegnies that serves both lifts 2 and 3, and the drawbridges, locks and fixed bridges strung along the waterway between them. Walking the towpath from one lift to the next is the best way to take it in, with each structure appearing ahead as a dark iron gateway across the canal.

In 2002 the giant Strépy-Thieu lift, a single funicular-style caisson lift with a rise of 73 metres, took over commercial traffic, and the old section was left to pleasure boats. That same year an accident at lift no. 1, when a caisson began to rise while a barge was leaving it, took the Houdeng-Goegnies lift out of service; a thorough restoration began in 2005. Seen together, the old lifts and their huge modern successor a short distance away make an unusually clear lesson in how the same engineering problem was solved a century apart.

Getting there

The lifts lie on the edge of La Louvière in the province of Hainaut; the town of Binche is about 8 km away. The nearest airport is Brussels South Charleroi (CRL), roughly 26 km to the south-east.