HOW THE STEAM ENGINE WORKS... ..........home - history -.inventors -.how it works diagram..........NEW MEDIA-GC243 / jlopez@ringling.edu

in the beggining...

Union Pacific Railroad Big Boy #4012, photo by Otto Perry.

online resources

1. http://en.wikipedia.org/wiki/Steam_locomotives

2. http://www.steamlocomotive.com

3. http://www.heritagerailways.com/

The earliest railways employed horses to draw carts over the track. As steam engines were developed in the 1700s, various attempts were made to apply these to railroad use. The first attempts were made in Great Britain; the earliest steam locomotive was built in 1804 by Richard Trevithick and Andrew Vivian. It ran with mixed success on the narrow gauge Penydarren tramway in Wales. These early efforts culminated in 1829 with Stephenson's Rocket, which was the first viable mainline locomotive.

Inspired by British success, the United States started developing steam locomotives in 1829 with the Baltimore and Ohio Railroad's Tom Thumb. This was the first locomotive to run in America, although it was intended as a demonstration of the potential of steam traction, rather than as a revenue-earning locomotive. The first successful steam railway in the US was the South Carolina Railroad whose inaugural train ran in December 1830 hauled by the Best Friend of Charleston. Many of the earliest locomotives for American railroads were imported from England, including the Stourbridge Lion and the John Bull, but a national locomotive manufacturing industry was quickly established, with locomotives like the DeWitt Clinton being built in the 1830s

The introduction of diesel-electric locomotives in the first part of the 20th century spelled the end of steam locomotives, though they were used in North America and Europe to mid-century, and continued in use in other countries to the end of the century. Steam locomotives are in general simple machines, which can be maintainable under primitive conditions and consume a wide variety of fuels. They are as a rule inefficient compared to modern diesels, requiring constant maintenance and labour to keep them operational. Water is required at many points throughout a rail network and becomes a major problem in desert areas, as are found in some regions within the United States, Australia and South Africa. In other localities the local water is unsuitable. The reciprocating mechanism on the driving wheels tend to pound the rails (see "hammer blow"), thus requiring more maintenance. Steam locomotives require several hours' boiling up before service and an end-of-day procedure to remove ash and clinker. Diesel or electric locomotives, by comparison, commence working from the first turn of the key and do not require the labour-intensive cleaning, raking and servicing after a shift. Finally, the smoke from steam locomotives is objectionable; in fact, the first electric and diesel locomotives were developed to meet smoke abatement requirements.

Mainline diesel-electric locomotives first appeared on the Baltimore and Ohio Railroad, in 1935 as locomotive No. 50. The diesel reduced operating and maintenance costs dramatically, while increasing locomotive availability. On the Chicago, Rock Island and Pacific Railroad the new units delivered over 350,000 miles a year, compared with about 120,000–150,000 for a mainline steam locomotive. World War II delayed dieselisation in the U.S.A, but the pace picked up in the 1950s, and by 1960 the last American Class I holdout, the Norfolk and Western Railway, discontinued steam operations. Some U.S. shortlines continued steam operations into the 1960s, and one steel mill continued to operate steam locomotives up to 1980.