The four boatlifts of the Canal du Centre, located 50 km south of Brussels, built between 1882 and 1917, span a total level difference of 66 meters, lifting boats up to 300 tons and use water as a power source. Each lift consists of two tanks, the lower tank with the boat is made lighter by releasing part of the water, the upper and heavier tank, filled with water, will then go down lifting the lower tank with the boat.