Strépy-Thieu boat lift
The Strépy-Thieu boat lift (French: L'ascenseur funiculaire de Strépy-Thieu) lies on a branch of the Canal du Centre in the municipality of Le Rœulx, Hainaut, Belgium. With a height difference of 73.15 metres (240 feet) between the upstream and downstream reaches, it is the tallest boat lift in the world, and will remain so until the Three Gorges dam boat lift in China is finished.
History
The boat lift was designed during the Canal du Centre's modernisation program in order to replace a system of two locks and four 16-metre lifts dating from 1888 to 1919. The canal itself began operations in 1879 and its locks and lifts were able to accommodate vessels of up to 300 tonnes. By the 1960s, this was no longer adequate for the new European standard of 1350 tonnes for barge traffic, and a replacement was sought.
Construction of the lift commenced in 1982 and was not completed until 2002 at an estimated cost of € 160 million (then 6.4 billion BEF), but once operational, permitted river traffic of up to the new 1350-tonne standard to pass between the waterways of the Meuse and Scheldt rivers. The lift increased river traffic from 256 kT in 2001 to 2,295 kT in 2006.
The four older lifts, now bypassed on the original line of the Canal du Centre to the south, are still in use, but are limited to recreational traffic only. Their architectural and historical value has led them to be placed on the UNESCO World Heritage list.
Design
The structure at Strépy-Thieu consists of two independent counterweighted caissons which travel vertically between the upstream and downstream sections. Due to Archimedes' Principle, the caissons weigh the same whether they are laden with a boat or simply contain water. In practice, variations in the water level mean that the mass of each caisson varies between 7200 and 8400 tonnes. The caissons have useful dimensions of 112 m by 12 m and a water depth of between 3.35 and 4.15 m. Each caisson is supported by 112 suspension cables (for counterbalance) and 32 control cables (for lifting/lowering) each of 85 mm diameter. The mass of the counterbalance was calculated to keep the tension in each of the control cables below 100 kN at all times. Four electric motors power eight winches per caisson via speed-reduction gearboxes and the 73.15-metre lift is completed in seven minutes. The suspension cables pass over idler pulleys with a diameter of 4.8 m. The structure is massively reinforced to provide rigidity against torsional forces during operation and has a mass of approximately 200,000 tonnes. The vertically moving watertight gates are designed to withstand a 5 km/h impact from a 2000 tonne vessel.
The boat lift is being promoted as a tourist attraction in its own right by the government of Hainaut. A pedestrian ticket for a one-way ride on the lift costs 5.50 euro.
See also
- List of boat lifts
- Lifts on the old Canal du Centre
- Ronquières inclined plane, 68 m high, Braine-le-Comte, Belgium – on the Brussels-Charleroi Canal
- Anderton boat lift
- Falkirk Wheel
- Peterborough lift lock
References
- Template:En icon"The Strépy-Thieu boat lift". Walloon Ministry of Civil Engineering and Transport. Retrieved 2006-05-07.
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