How much horsepower to move the falkirk wheel?
It takes 22.5kW – or about 30hp “The wheel, which has an overall diameter of 35 metres, consists of two opposing arms which extend 15 metres beyond the central axle and which take the shape of a Celtic-inspired, double headed axe. Two sets of these axe shaped arms are attached about 25 metres apart, to a 3.5 metre diameter axle. Two diametrically opposed water filled caissons each with a capacity of 80,000 gallons, (302 tons each), are fitted between the ends of the arms. These caissons always weigh the same whether or not they are carrying their combined capacity of 600 tonnes of floating canal barges as, according to Archimedes’ principle, floating objects displace their own weight in water, so when the boat enters the amount of water that leaves the caisson is exactly the same as the weight of the boat. This keeps the wheel balanced and so, despite its enormous mass, it rotates through 180° in less than four minutes while using very little power.
