Hold the Lox: The Falkirk Wheel Goes Higher, Faster

falkirk wheel overall photo
Images via Wikipedia

When I showed the amazing Peterborough lift lock, a commenter and Kottke both pointed out that the Falkirk Wheel in Scotland goes higher, faster. It was built as part of an attempt to regenerate canals in central Scotland, and replaces 11 locks that had fallen into disuse. It also is another example of the clever and original results that come from design competitions- it is now a serious attraction.falkirk wheel animation

Like Peterborough, it relies on Archimedes principle to stay balanced; the weight of the boat displaces the same weight of water.

But unlike Peterborough, it needs electricity. According to Kottke:

These caissons always weigh the same whether or not they are carrying their combined capacity of 600 tonnes (590 LT; 660 ST) 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 leaving the caisson weighs exactly the same as the boat. This keeps the wheel balanced and so, despite its enormous mass, it rotates through 180° in five and a half minutes while using very little power. It takes just 22.5 kilowatts (30.2 hp) to power the electric motors, which consume just 1.5 kilowatt-hours (5.4 MJ) of energy in four minutes, roughly the same as boiling eight kettles of water.

falkirk ring gear photo
just look at those ring gears that keep the tanks vertical. According to Wikipedia:
The caissons need to rotate at the same speed as the wheel but in the opposite direction to keep them level and to ensure that the load of boats and water does not tip out when the wheel turns.

Each end of each caisson is supported on small wheels which run on the inside face of the eight-metre-diameter holes at the ends of the arms, allowing the caissons to rotate. The rotation is controlled by means of a train of gears: an alternating pattern of three eight-metre-diameter ring gears and two smaller idler gears, all with external teeth. The central large gear acts as a stationary sun gear. It is fitted loosely over the axle at its machine-room end and fixed to a plinth to prevent it from rotating. The two, smaller, idler gears are fixed to each of the arms of the wheel at its machine-room end and act as planet gears. When the motors rotate the wheel, the arms swing and the planet gears engage the sun gear, which results in the planet gears rotating at a higher speed than the wheel but in the same direction. The planet gears engage the large ring gears at the end of the caissons, driving them at the same speed as the wheel but in the opposite direction. This cancels the rotation due to the arms and keeps the caissons stable and perfectly level.

falkirk wheel panorama photo

The British government made a big investment in their canal system, (£17.5 million on the Wheel, £84.5 million on the canal revitalization). Unlike the proprietors of the Erie Canal in the States, they see that canals have a role to play in tourism and transportation.

The infrastructure is there, it's time to throw some stimulus at it.

More on Canals:
Water Powered Lift Lock is an Engineering Marvel
Transport By Barge on the Erie Canal Uses a Tenth of The Fuel of a Truck
UK Canal Freight Under Scrutiny: 80% Less CO2 Than Road Haulage ...
Supermarket Delivers By Barge to Save Emissions : TreeHugger

Tags: Transportation


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