Patenting of the High-Pressure Steam Engine

Date March 24, 1802

The expiration of Watt’s steam engine patent in 1800 opened the way for Richard Trevithick’s design of the portable, high-pressure steam engine, which in turn led to the development of locomotives and railroads.

Locale Great Britain

Key Figures

• Richard Trevithick (1771-1833), developer of the high-pressure steam engine
• George Stephenson (1781-1848), developer of the first successful railroad locomotive
• James Watt (1736-1819), proprietor, with Matthew Boulton, of the Soho Engineering Works, manufacturers of early steam engines
• John Wilkinson (1728-1808), inventor of improved method of boring cannon and cylinders

Summary of Event

The eighteenth century saw the emergence of the steam engine, the mechanism by which artificial sources of power were to be widely applied to many forms of production. Throughout that century, use of the steam engine spread mostly in the mines of Great Britain, chiefly as a source of pumping power to empty the mines of water but also as a motive power for transporting the products of the mines, primarily coal and iron.

Nineteenth century industry expanded the use of steam power, using it to operate the machinery in the factories growing across the landscape. Most important, however, was the use of steam power to operate the locomotives that made modern railroads possible. The engines of the eighteenth century were of two kinds: those designed by Thomas Newcomen at the beginning of the century and those designed by James Watt in the latter half of the century. Both types, however, used steam to create a vacuum. (Air pressure filled the vacuum and created the motive power of these engines.) Unlike Newcomen, Watt was highly successful in gaining patent protection for his engines, which enabled him to disapprove of any developments that might increase the power of the engines, notably the use of high-pressure steam rather than a vacuum to move the piston in the cylinder.

Changes in the use of high-pressure steam were not prevented by Watt’s patents alone, however; other technologies, notably in the field of metallurgy, also had to occur before the power of high-pressure steam could be put to use. One of these changes was the development of better quality cast iron so that more trustworthy cylinders could be made, cylinders with uniform dimensions in which the piston fitted tightly. This development was spearheaded by the Darby family of Coalbrookdale, whose experiments with iron ore smelted with coal led to the creation of reliable cast-iron cylinders. Furthermore, the creation of effective boring machinery, which led to the accurate boring out of a cylinder, rested on the work of John Wilkinson , whose boring machine was designed primarily to bore out cannon. Finally, the development of iron manufacture generally made possible the creation of boilers, which could raise steam to high pressure without bursting.

The expiration of Watt’s patents in 1800 unleashed a flood of new, high-pressure steam engines. Richard Trevithick was the first of many to build steam engines using high-pressure steam. In 1800, he built one for Cook’s Kitchen Mine, in Cornwall, proving this type of engine’s usefulness. On Christmas Eve, 1801, he had completed a steam engine that ran on the roads in Cornwall, proving the usefulness of this type of engine for locomotion. He then demonstrated his engine to Count Rumford, in London, and applied for a patent, which was awarded to him on March 24, 1802.

The great advantage of Trevithick’s high-pressure steam engine was that its cylinder and piston could be quite small, and because he dispensed with the condenser that was an integral part of the Watt engines, the new engine was relatively light in weight. These factors made Trevithick’s engine portable. Previous versions of the steam engine, which had been used mostly in mines for pumping water or moving the mined material to the surface, had been stationary. Also, the new engines were commonly called puffers because they vented exhausted steam into the air instead of condensing the steam, as in Watt engines.

The power generated by the Trevithick engines was about ten times that of the contemporary Watt engines, even though the Trevithick engines were generally smaller. Trevithick demonstrated the potential of this great increase in power in 1804 at an iron mine near Merthyr Tydfil in Wales. One of his engines had hauled a load of ten tons for nearly ten miles at five miles per hour. As it turns out, this engine had been the first locomotive, for it ran on iron rails, was steered by one man, and it pulled five freight cars and seventy men who were on board. This demonstrated that using iron rails was the way to go: The iron rails kept the machine on the intended route, and the friction between wheel and rail helped propel the train.

The rapidly growing demands placed on England’s mines propelled the new high-pressure steam engine forward. Traditionally, much of the demand had been concentrated in the ancient tin and lead mines of Cornwall. By Trevithick’s time, iron and coal were needed most. Coal in particular was in high demand, because the shortage of fodder during the Napoleonic Wars constrained the supply of horses for industrial transport. Mines, with their heavy materials, needed better ways to retrieve their coal stores and move them into the transportation system. Engines began to replace horses, pulling coal cars along the rails that miners had long since found to be the easiest way to bring the coal to the surface. It was not surprising, then, that the rapidly developing coal mines in the north of England were ready to adopt the new system of transportation.

The person who made that transfer possible was George Stephenson. Stephenson began his career as a mine superintendent. In 1812 he was put in charge of a group of coal mines in the vicinity of Newcastle, called the Grand Allies. At a mine in Killingworth the previous year, Stephenson had rebuilt the pump that removed the water filling the mine; his success led to his appointment as a mine superintendent. As superintendent he devoted himself to improving the ways in which the coal was moved from the mine, using the wagon way to move the material over cast-iron rails. He soon realized, however, that wrought iron would be a better material, and that flanged wheels would link the engine securely to the rails. A portable engine with high-pressure steam, combined with the secure locomotion provided by well-placed wrought iron rails, made rail travel possible.

Trevithick’s reputation was established beyond challenge when he designed and operated the Stockton and Darlington Railway . Also, an engine of his design successfully competed in the famous locomotive trials at Rainhill in October, 1829, in which Stephenson, using a tubular boiler to increase the production of steam, won the trials with his locomotive called “Rocket.” Stephenson’s “tubular” method became standard in steam-engine boilers. He also increased the engine’s power by connecting the piston rod directly to the wheels instead of running the wheels through a system of gears. Both of these innovations became standard features of railroad locomotives.

Stephenson became, with his son Robert, a powerhouse of the railroad industry as well. The pair produced many of the engines on the early railroads of England, and their designs clearly revealed the potential of this new technology.

Significance

In many respects the railroad was the signature technology of the nineteenth century. The work of Trevithick and Stephenson, conducted within the short span of thirty years, created a whole new industry that laid the foundation for the nineteenth century’s transportation revolution.

Bibliography

Briggs, Asa. The Power of Steam: An Illustrated History of the World’s Steam Age. Chicago: University of Chicago Press, 1982. A well-illustrated account of the adoption of steam power. Includes many useful diagrams.

Cardwell, D. S. L. Turning Points in Western Technology: A Study of Technology, Science, and History. New York: Science History, 1972. Highlights significant inventions in the history of technology in the Western world.

Derry, T. K., and Trevor L. Williams. A Short History of Technology from the Earliest Times to A.D. 1900. Oxford, England: Oxford University Press, 1960. Sets the important inventions in context.

Kirby, Maurice W. The Origins of Railway Enterprise: The Stockton and Darlington Railway, 1821-1863. New York: Cambridge University Press, 1993. A well-written study of the earliest commercial railroad.

Mokyr, Joel. The Lever of Riches: Technological Creativity and Economic Progress. New York: Oxford University Press, 1990. Shows how technology makes possible economic advances.

Tunzelmann, G. W. von. Steam Power and British Industrialization to 1860. Oxford, England: Clarendon Press, 1978. Explores steam power’s role in industrialization in the first half of the nineteenth century.