On this day in engineering history, the first self-propelled
steam locomotive ran on cast-iron rails along the Penydarren Tramroad at
Merthyr Tydfil in Wales.
Built by Richard Trevithick, a British inventor and pioneer of "strong steam",
the Penydarren locomotive was equipped with a single vertical cylinder, an
8-foot flywheel, and a long piston-rod. While hauling 10 tons of iron and 70
passengers from Samuel Homfray's ironworks to the Merthyr-Cardiff Canal,
Trevithick's one-stroke steam engine traveled 9 miles and reached speeds of 5
mph. By turning the exhaust steam up the chimney, the Penydarren locomotive produced
a draft which could draw hot gases from the fire through the boiler.
Ultimately, Richard Trevithick's Penydarren
locomotive made only three trips. During each of its runs to the Merthyr-Cardiff Canal, the seven-ton steam engine
damaged the soft cast-iron rails of Samuel Homfray's narrow-gauge railway,
convincing Trevithick's employer that a self-propelled steam engine was
unlikely to reduce transportation costs. Adhesion was also a problem since
smooth, iron wheels running on smooth, iron rails resulted in considerable
slipping. Years later, John Blenkinsop, the manager of Middleton Colliery,
designed a rack railway with cog-toothed driving wheels. The Blenkinsop
locomotives were fairly expensive to use, however, and showed heavy wear
between the driving gear wheel and the horizontal rack. Later, in 1814, William
Hedley would solve the problem of adhesion with "Puffing Billy", a steam locomotive
whose design applied power to the rails through two sets of driving wheels.
Although Richard Trevithick's
Penydarren locomotive enjoyed only short-lived success, "The Cornish Giant" (as
the 6' 2" inventor was known) would continue to pioneer the use of strong
steam. After narrowly avoiding death when a railway tunnel he was building
collapsed, Trevithick returned to his native Cornwall and designed a locomotive called
"Catch Me Who Can". For a shilling apiece, thrill seekers could visit
"Trevithick's steam circus" and travel at speeds up to 12 mph around
Torrington Square, near the present day Euston station in London. "Catch
Me Who Can" was too heavy for its cast-iron rails, however, and financial
difficulties forced Trevithick to abandon the circular railway's collapsed
tracks.
Resources:
http://cr4.globalspec.com/blogentry/1586/Richard-Trevithick-Part-1
http://cr4.globalspec.com/blogentry/1587/Richard-Trevithick-Part-2
http://cr4.globalspec.com/blogentry/1577
http://en.wikipedia.org/wiki/History_of_rail_transport
http://www.spartacus.schoolnet.co.uk/RAtrevithick.htm
http://www.victorianweb.org/technology/railway1.html
http://www.spartacus.schoolnet.co.uk/RAblenkinsop.htm
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