Engines of Our Ingenuity

No. 82:
ROADS, CANALS, AND RAILWAYS

by John H.Lienhard

Click here for audio of Episode 82.

Today, we look at roads, canals, and railways. The University of Houston's College of Engineering presents this series about the machines that make our civilization run, and the people whose ingenuity created them.

England's 18th-century industrial revolution created a pressing need to haul raw and manufactured goods. The English never had been serious road-builders. They'd done little to surpass their old Roman road system in 1500 years' time. But they did build up a very effective canal system in the latter 1700s.

They also developed a railway system; and that catches us by surprise, because the steam locomotive wasn't invented until much later. But these were horse-drawn trains. Since roads were so bad, canals became the major means for hauling goods. But some cross-country portaging had to be done between canals, and roads couldn't stand up to heavy wheeled vehicles. So the English developed horse-drawn railways for portage. The idea originally came out of the mines, where tramways were used to move coal and ore. When the steam locomotive was finally invented, the technology of building railways was well developed.

Engineers also knew a lot about the loads horses could pull. At a slow walk, a horse could pull almost 30 tons through a canal but only 7 tons on a railway. As he sped up to a trot, water resistance became so great that he could pull almost nothing. But on a railway, he could pull just as much trotting as walking. That meant that the same horse could move more goods on a canal; but when speed was needed, he did much better on a railway.

Trevethick built the first steam locomotive in 1804, and railroad speeds increased rapidly from then on. Water resistance made canals quite useless at the speed of a train. So from the early 19th century until the modern automobile, railways dominated English transportation.

The land locomotive -- the early steam car -- made a valiant try during those years. But it was easier to develop a rail system than a road system that could support such heavy vehicles.

So many factors were at play in that brief 80-year period! Who could have guessed the outcome in 1760, when roads, rails, and canals began to compete for supremacy? That's a sobering question as we watch the competition among the systems that make up today's technologies. Can any of us guess what form our transportation will take in another 80 years -- or our military defense systems, or our computer systems?

I'm John Lienhard, at the University of Houston, where we're interested in the way inventive minds work.

(Theme music)


This episode has been greatly rewritten as Episode 1509.


From the 1832 Edinburgh Encyclopaedia

Typical early-19th-century British road construction


The Engines of Our Ingenuity is Copyright © 1988-1997 by John H. Lienhard.

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