Where does engineering end and art begin? If this unique rotating boat lift - nothing like it has ever been built before - were solely functional, how different would it look? But the Falkirk Wheel was never intended for function alone. Appearance was a consideration. As designer Tony Kettle put it, the aim was to create something "sculptural" that would be "a celebration, a statement." The hooked leading edges of the caissons give them a sense of movement.
Opened in May 2002, the wheel certainly works effectively. Using extraordinarily little power, it speedily and efficiently lifts boats and water some 115 feet up or down between two renovated Scottish canals. (The Union Canal is the lower, the Forth and Clyde Canal the upper.) The wheel rotates silently, lifting and lowering the two balanced caissons containing boats and water. It is an original solution to the centuries-old problem of enabling canal boats to negotiate changes of level.
The word "wheel" was retained from earlier proposals. And although rotation is still the essential concept of the final design, the structure has more to do with Roman aqueducts than with wheels. The beauty of those aqueducts, often a progression of supporting arches striding over the landscape, was a direct inspiration. Part of the upper level of the design is, indeed, an aqueduct. The wheel, bearing the higher caisson, breaks away from this aqueduct as it revolves. Unlike conventional locks, there is no changing of water levels at all.
Other references for the appearance of the wheel were fish and the revolver. The aqueduct was inspired by the elegant skeleton of a fish; the rotational structure turns like a gun chamber - though the canal boats are not exactly fired from the caissons when they arrive at their new level. They move out of them steadily, ready to resume their floating journey.
You know how it is: You have the Leaning Tower of Pisa, the Eiffel Tower, the Hanging Gardens of Babylon on your doorstep. Hordes of eager tourists flock to see them year-round. But you - not surprisingly - are much too busy with daily life to spend time staring at the object of wonder that faces you continually.
I worked in New York for years, but never went up the Empire State Building. It's been like that with the Falkirk Wheel. This much acclaimed, much visited wonder of engineering and imagination is a short drive from us. Since its opening, everyone else seems to have had an uplifting ride on it.
Finally, one fine autumn day, more than a year after its inauguration (by the queen, in May 2002) we joined the pilgrimage to this giant revolving boat lift.
I'd seen pictures; I'd studied the website. I had read and heard that there was nothing like it in the world. I was impressed. But as we were walking up toward the thing itself, I realized I had no idea what it was like. It strode across the grassy slope of a hill like some gigantic alien construct. It's a mix of many things: modern sculpture, modern architecture, art, engineering. It looked like a hybrid of two gigantically elegant swans and two slightly threatening claw hammers.
We joined the line, the motionless wheel towering over us, and stood waiting to file onto the moored barge.
It seemed to me, looking up, that the wheel is designed to be a symbol. A symbol of "now." It was designed to look promising and aspirational. At the same time, it is actually functional.
It also represents an unashamed link to the past - to the triumphant inventiveness of Britain's industrial past and the hardware of Britain's old canal network, its systems, engineering, and architecture. This past, I thought, as we clambered down into the boat, is what fascinates so many of us. Canals, no longer utilitarian, have become part of our heritage. Once slicing up our landscape, they now seem perfectly at home in it. It is easy to forget they are artificial.
Once packed with its human cargo, our narrow boat eased into the chamber. The "wheel" revolves in order to lift up - and down - long caissons filled with water on which, temporarily captive, barges and boats float. Which was what we were now doing. It was novel, but at the same time seemed quite familiar.
Britain lives simultaneously (and not always with perfect ease) in its past and its present. Our waterways, for instance, which in the 18th century were the cutting edge of modern transportation, have outlived their original role. They have turned into havens for quiet tourists keen to mess about in boats. But many of our canals have fallen on bad times, sliced through by roads, filled in, vandalized, silted up.
Happily, our canals today also have the support of a surprisingly effective lobby of enthusiasts. And there is something about canals - something more than simple nostalgia - that has brought about programs of renewal and repair. I think this may be partly because we are fascinated by the idea, inherent in canals, of "linking." Canals were often built to link different coasts, different rivers, different cities. Today, they also link the present and the past. We want unbroken links.
The two once defunct canals that are now rejoined by the Falkirk Wheel - the Union Canal and the Forth and Clyde Canal - link Scotland's two major cities, Glasgow and Edinburgh, and also link Scotland's west and east coasts.
Our pilot now addressed us as if we were about to set out on a transatlantic crossing. A few minutes later, we suddenly noticed we were airborne. The wheel turns almost soundlessly - an indication of the very small amount of power needed to move it and lift us 115 feet aloft, while (a neat balancing act) another barge is lowered on the opposite arc. This ascent/ descent took seven minutes and was stunningly uneventful. And then we were floating out onto the upper reach of canal just as if nothing particularly ingenious had actually occurred.
But, of course, it had. You could see it in the faces of those passengers who knew. My thoughts cast back to my childhood in Bingley, Yorkshire, and the canal near our home. In it were two sets of locks, one a three-rise, the other a five-rise. The locks are still there, intact and working. They rise almost 60 feet. Engineered in the 18th century, they consist of a robust system of gates, chambers, and sluices. As a boy I would watch entranced as boats - full of coal, wool, and other raw materials - passed through the five-rise locks. It involved plenty of rushing and gurgling, plenty of crude shouting, a deal of muscle power - and a lot of patience. The whole process took about 90 minutes.
The seven-minute Falkirk Wheel is a fascinating - and beautiful - triumph of 21st-century engineering and design. But, costing £17.3 million ($31 million), it seems unlikely to become the model for replacing traditional locks.
Both this old and new engineering seem to me magical and admirable. I am glad I knew the old locks when I was a child. And I am glad the Falkirk Wheel is now (almost) on our doorstep. I have already paid it a second visit.