Strépy-Thieu Boat Lift
Touring in Belgium and visiting the cities of Mons (Bergen) and Namur (Namen) we made a small detour to visit the Strépy-Thieu Boat Lift.
In 2002 the boat lift of Strépy-Thieu was completed, almost 20 years after its construction started. Together with a deviation in the Central Canal it replaces 4 historical boat lifts. The Central Canal connects the Meuse and Scheldt rivers. Two rivers important for water transportation in Belgium. Until a boat lift in China ( 3 gorges dam lift) will be completed, the Strépy-Thieu Boat Lift is the largest boat lift of the World. On the photo both caissons are hanging in the air just under the building and in connection with the upper branch of the canal.
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. The suspension cables pass over idler pulleys with a diameter of 4.8 m. Four electric motors power eight winches per caisson via speed-reduction gearboxes and the 73.15-metre lift is completed in seven minutes. 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.
Unfortunately we had no time to visit the 4 old boat lifts that are on the Unesco World Heritage list. Neither could we visit the Ronquières inclined plane which is in the vicinity.