Steam Engines

Steam engines were used as the prime mover in pumping stations, locomotives, steam ships, traction engines, steam lorries and other road vehicles. They were essential to the Industrial Revolution and saw widespread commercial use driving machinery in factories and mills, although most have since been superseded by internal combustion engines and electric motors.

Steam turbines, technically a type of steam engine, are still widely used for generating electricity. About 86% of all electric power in the world is generated by use of steam turbines.

A steam engine requires a boiler to heat water into steam. The expansion of steam exerts force upon a piston or turbine blade, whose motion can be harnessed for the work of turning wheels or driving other machinery. One of the advantages of the steam engine is that any heat source can be used to raise steam in the boiler; but the most common is a fire fueled by wood, coal or oil or the heat energy generated in a nuclear reactor.

The first recorded steam-powered device, the aeolipile, was described by Hero of Alexandria (Heron) in 1st century Roman Egypt, in his manuscript Spiritalia seu Pneumatica. Steam ejected tangentally from nozzles caused a pivoted ball to rotate; this suggests that the conversion of steam pressure into mechanical movement was known in Roman Egypt in the 1st century, the device was used for some simple work, such as opening temple doors, but saw no other major uses.

The first practical steam turbine was invented much later by Taqi al-Din, an Arab philosopher, astronomer, and engineer in 16th century Ottoman Egypt, who exposed a method for rotating a spit by means of a jet of steam playing on rotary vanes around the periphery of a wheel.

A similar machine is shown by Giovanni Branca, an Italian engineer, in 1629 for turning a cylindrical escapement device that alternately lifted and let fall a pair of pestles working in mortars. The steam flow of these early steam turbines, however, was not concentrated and much of its energy was dissipated in all directions and would have led to a considerable waste of energy and are usually called "mills".

Commercial development of the steam engine, however, required an economic climate in which the developers of engines could profit by their creations.[citation needed] Classical, and later Medieval and Renaissance civilisations provided no such climate.[citation needed] Even as late as the 17th century, steam engines were created as one-off curiosities.

The difficulty in breaking out of this situation is evident judging by the difficulties encountered by Edward Somerset, 2nd Marquess of Worcester and later by his widow in gaining financial investment into the practical application of his ideas for the exploitation of steam power.[citation needed] In 1663, he published designs for, and installed a steam-powered device for raising water on the wall of the Great Tower at Raglan Castle (the grooves in the wall where the engine was installed were still to be seen in the 19th century). However, no one was prepared to risk money in this revolutionary new concept, and without backers the machine remained undeveloped.

Engines