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.
