TCS Daily

One-Wheel Wonder

By Ralph Kinney Bennett - April 27, 2007 12:00 AM

Somewhere in ancient China, possibly in the 1st century B.C., a wagon or a horse cart carrying supplies in a military column was smashed to pieces in an accident. A soldier moving the damaged wagon out of the way picked up a shattered section which was still attached to one wheel. Using the wheel, he propelled the piece of wreckage off the roadway and as he did so he experienced one of those little practical epiphanies that have meant so much to civilization.

Rather than pick up and carry the rest of the wreckage and the contents of the wagon off the road, he balanced them on his impromptu one-wheeled "tool" and swiftly cleared the way. Thus, perhaps, was born one of the most elegant and useful tools ever invented by man - the wheelbarrow.

The exact time and place of this ingenious mating of the principle of the lever and the mobility of the wheel cannot be exactly determined, shrouded as it is in the mist of time and legend. A Chinese general, Chuko Liang (181-234 A.D.) is often credited with the invention of the wheelbarrow and its subsequent use transporting military supplies. The Chinese army reportedly found that this device gave it such a logistical advantage that it tried to keep it a military secret for as long as possible.

But the invention of such an extraordinarily useful tool may well predate Chuko and have had many mothers named Necessity. There is, for instance, an intriguing reference to what may have been a wheelbarrow in inventories of tools and materials used in the building of the Greek temple at Eleusis, four centuries before Christ. These lists mention the frames or bodies for two- and four-wheeled vehicles - possibly construction carts. But they also refer to a body for a "one-wheeler" (hyperteria monokyklou). However, no remains or depictions of a wheelbarrow have ever been found in the archaeology of ancient Greece or Rome.

Most early Chinese wheelbarrows placed the load directly over the wheel (or wheels; the Chinese often used two for something akin to a rickshaw). These vehicles were either pushed (a "gliding horse") or pulled (a "wooden ox"). In one common model, a single large diameter spoked wheel was surrounded by a wooden platform or box at axle height. The load was distributed on either side of this wheel in a manner not unlike the saddlebags or panniers on either side of the rear wheel of a motorcycle.

Such wheelbarrows were used to carry loads over long distances on narrow roads and even tortuous footpaths. A Chinese writer in 1200 A.D. marvels at such a device: "Ways which are as winding as the bowels of a sheep will not defeat it."

Europeans seem to have come late to the wheelbarrow game but they vastly improved its capabilities by refining the design. References or depictions of wheelbarrows do not appear in Europe until the late 12th and early 13th centuries. But the European models were very different from the Chinese. They exploited the leverage principle to a much greater degree by simply moving the wheel to the front of the load and making it of smaller diameter. In addition, the European wheelbarrows had long handles, curved in various fashions to aid in lifting and balancing loads.

These important design changes immensely increased the leverage advantage and allowed a single worker to lift and carry heavy loads without hoisting them to waist or shoulder height. And with the single wheel he could negotiate difficult terrain with remarkable dexterity. An illustration in an illuminated manuscript from 1286 (see here) shows a single laborer moving what appear to be carved stone blocks on a wheelbarrow with elegantly curved frame and handles.

In Medieval Europe before the advent of the wheelbarrow, paving or building stones, bricks, gravel and other heavy materials were moved about construction sites by two or more men carrying the loads between them on handbarrows or "stretchers." It was backbreaking work, done inefficiently. Lifting these heavy loads was a strain and carrying them at roughly waist height was difficult except over short distances. The two men carrying the load had to coordinate their movements and keep the load level over difficult ground or a narrow passage.

But the wheelbarrow permitted the carriage of even heavier loads with greater ease. At the minimum it permitted one man to do the work of two. It therefore brought about a tremendous increase in productivity that was quickly grasped by builders. Andrea Matthies, an expert on medieval art history, notes that the earliest archival reference to wheelbarrows in Europe is an order for eight wheelbarrows built by a carpenter in Canterbury for use at a royal construction site in Dover.

The wheelbarrow has of course been refined over the centuries (there are even motorized versions), but there have been no changes to its basic and ingenious geometry. One significant change, in the 1970s, was English inventor and entrepreneur James Dyson's "ballbarrow," (see here) which substituted a spherical pneumatic wheel, giving the barrow greater maneuverability, particularly over sand or soft, wet ground. Curiously, this innovation enjoyed brief success but never caught on.

The sheer significance of the wheelbarrow may be difficult to grasp now that they are so ubiquitous and commonplace. Maybe you'll be gardening this weekend and moving, say, sacks of topsoil, around in a wheelbarrow. Notice how relatively easy it is to move a heavy load around your yard. You don't need to get into all the physics involved, but just stop and think for a moment about doing this work without a wheelbarrow.

In my own case, the grounds around our house are hilly. Moving a heavy load of lawn debris down a steep hill to our compost area in the woods is a tricky thing in our two wheeled garden cart or even the small wagon pulled by our garden tractor. But with a wheelbarrow's single wheel I can easily move laterally down and across the face of the hill, balancing the load toward the slope. And once to the site, I just tip it over and dump the load. Leverage! Elegant! Ingenious!

And to whomever stumbled upon this idea long ago, thanks.



Command v. competition
I've read before of the mystery of Chinese science and technology's short-lived nature (Charles Murray, Human Achievement). Perhaps the answer to this mystery is that in a command society like China's, where the political administration's order to supply a novel contrivance determined the advantage of its supply, the knowledge of a technology's competitive advantage in the highest administrative levels was determinative of that technology's forward survival. Hence, the technological ignorance or knowledge of the highest administration determined which technologies survived and which didn't.

In contrast, consider a technology's impact on Europe's decentralized and balkanized feudalism, where any competitive advantage lent by technology led to acquired lands, wealth and power, e.g. the longbow. Here, an arms race of technology punishing administrative amnesia lent impetus not only to acquiring new technologies but countering them with new ones, as well (Leonardo, anyone?). In such an environment, a dark age could not endure a renaissance and enlightenment.

Cheers, Bennett.

And thus the demise of humanity is wrought not by the sword but by the wheelbarrow...

What's that supposed to mean? The world isn't demising by either thing, it's getting better, right?

I was joking. I found it amusing that it was a military secret at one time...

Conceptual breakthroughs...
Interesting how such ideas seem so obvious once someone actually creates a working model. Talk about it all you want. No one is listening.

Every such thing is impossible until we know how to do it. Then it is easy.

Wheel is real wonder invention by mankind
Frist great invention is fire and second is wheel, both change the entire history of mankind.

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