A steam locomotive is a type of locomotive that provides the force to move itself and other vehicles by means of the expansion of steam. It is fuelled by burning combustible material (usually coal, coke, oil or, rarely, wood) to heat water in the locomotive's boiler to the point where it becomes gaseous and its volume increases 1,600 to 1,700 times. Functionally, it is a self-propelled steam engine on wheels. In most locomotives the steam is admitted alternately to each end of its cylinders in which pistons are mechanically connected to the locomotive's main wheels. Fuel and water supplies are usually carried with the locomotive, either on the locomotive itself or in a tender coupled to it. Variations in this general design include electrically powered boilers, turbines in place of pistons, and using steam generated externally. Steam locomotives were first developed in the United Kingdom during the early 19th century and used for railway transport until the end of the 20th century. Richard Trevithick built the first steam locomotive known to have hauled a load over a distance at Pen-y-darren in 1804, although he produced an earlier locomotive for trial at Coalbrookdale in 1802. Salamanca, built in 1812 by Matthew Murray for the Middleton Railway, was the first commercially successful steam locomotive. Locomotion No. 1, built by George Stephenson and his son Robert's company Robert Stephenson and Company, was the first steam locomotive to haul passengers on a public railway, the Stockton and Darlington Railway, in 1825. Rapid development ensued; in 1830 George Stephenson opened the first public inter-city railway, the Liverpool and Manchester Railway, after the success of Rocket at the 1829 Rainhill Trials had proved that steam locomotives could perform such duties. Robert Stephenson and Company was the pre-eminent builder of steam locomotives in the first decades of steam for railways in the United Kingdom, the United States, and much of Europe. Towards the end of the steam era, a longstanding British emphasis on speed culminated in a record, still unbroken, of 126 miles per hour (203 kilometres per hour) by LNER Class A4 4468 Mallard; however, there are long-standing claims that the Pennsylvania Railroad class S1 achieved speeds upwards of 150 mph, though this was never officially proven. In the United States, larger loading gauges allowed the development of very large, heavy locomotives such as the Union Pacific Big Boy, which weighs 540 long tons (550 t; 600 short tons) and has a tractive effort of 135,375 pounds-force (602,180 newtons). Beginning in the early 1900s, steam locomotives were gradually superseded by electric and diesel locomotives, with railways fully converting to electric and diesel power beginning in the late 1930s. The majority of steam locomotives were retired from regular service by the 1980s, although several continue to run on tourist and heritage lines.
History
Britain The earliest railways employed horses to draw carts along rail tracks. In 1784, William Murdoch, a Scottish inventor, built a small-scale prototype of a steam road locomotive in Birmingham. A full-scale rail steam locomotive was proposed by William Reynolds around 1787. The authenticity and date of this locomotive is disputed by some experts and a workable steam train would have to await the invention of the high-pressure steam engine by Richard Trevithick, who pioneered the use of steam locomotives.
The first full-scale working railway steam locomotive was the 3 ft (914 mm) gauge Coalbrookdale Locomotive built by Trevithick in 1802. It was constructed for the Coalbrookdale ironworks in Shropshire in the United Kingdom though no record of it working there has survived. On 21 February 1804, the first recorded steam-hauled railway journey took place as another of Trevithick's locomotives hauled a train along the 4 ft 4 in (1,321 mm)-wide tramway from the Pen-y-darren ironworks, near Merthyr Tydfil, to Abercynon in South Wales. Accompanied by Andrew Vivian, it ran with mixed success. The design incorporated a number of important innovations that included using high-pressure steam which reduced the weight of the engine and increased its efficiency. Trevithick visited the Newcastle area in 1804 and had a ready audience of colliery (coal mine) owners and engineers. The visit was so successful that the colliery railways in north-east England became the leading centre for experimentation and development of the steam locomotive. Trevithick continued his own steam propulsion experiments through another trio of locomotives, concluding with the Catch Me Who Can in 1808, first in the world to haul fare-paying passengers.
In 1812, Matthew Murray's successful twin-cylinder rack locomotive Salamanca first ran on the edge-railed rack-and-pinion Middleton Railway. Another well-known early locomotive was Puffing Billy, built 1813–14 by engineer William Hedley. It was intended to work on the Wylam Colliery near Newcastle upon Tyne. This locomotive is the oldest preserved, and is on static display at the Science Museum, London.
George Stephenson George Stephenson, a former miner working as an engine-wright at Killingworth Colliery, developed up to sixteen Killingworth locomotives, including Blücher in 1814, another in 1815, and a (newly identified) Killingworth Billy in 1816. He also constructed The Duke in 1817 for the Kilmarnock and Troon Railway, which was the first steam locomotive to work in Scotland. In 1825, Stephenson built Locomotion No. 1 for the Stockton and Darlington Railway, north-east England, which was the first public steam railway in the world. In 1829, his son Robert built in Newcastle The Rocket, which was entered in and won the Rainhill Trials. This success led to the company emerging as the pre-eminent builder of steam locomotives used on railways in the UK, US and much of Europe. The Liverpool and Manchester Railway opened a year later making exclusive use of steam power for passenger and goods trains.
United States
… excerpt ends here. Continue reading the full article.
