|
By
the 1820's in the United States, when steamboats were common on western
waters, these boats were mostly powered by engines built in the West
(Pittsburgh, Cincinnati or Louisville), and of a distinctive western design
specially suited to western needs. The first steam engines in practical use
in England and the United States were of low-pressure design. This was the
type first developed by James Watt, then manufactured by the firm of
Boulton and Watt, and long the standard industrial engine. Steam was
accumulated in a large, double-acting vertical cylinder, but the steam
reached only a few pounds of pressure per square inch. It was low-pressure
engines of this type that were first introduced into the United States by
Robert Fulton. He imported such a Boulton and Watt engine from England to
run the Clemont. But this type of engine was expensive and complicated,
requiring many precision-fitted moving parts.
The
engine that became standard on western steamboats was of a different and
novel design. It was the work primarily of an unsung hero of American
industrial progress Oliver Evans (1755- 1819). The self-educated son of a
Delaware farmer, Evans early became obsessed by the possibilities of
mechanized production and steam power. As early as 1802 he was using a stationary
steam engine of high-pressure design in his mill. Engines of this type were
not unknown, but before Evans they were generally considered impractical
and dangerous.
Within
a decade the high-pressure engine, the new type had become standard on
western waters. Critics ignorant of western conditions often attacked it as
wasteful and dangerous. But people who really knew the Ohio, the Missouri
and the Mississippi insisted with good reasons, that it was the only engine
for them. In shallow western rivers the weight of vessel and engine was important,
a heavy engine added to the problem of navigation. The high-pressure engine
was far lighter in proportion to horsepower, and with less than half as many
moving parts was much easier and cheaper to repair. The main advantages of
low-pressure engines were safe operation and economy of fuel consumption,
neither of which meant much in the West.
|
No comments:
Post a Comment
thank you for visiting my blog and for your nice comments