Beam engine in the context of "Beam (structure)"

Engineering is the practice of using natural science, mathematics, and the engineering design process to solve problems within technology, increase efficiency and productivity, and improve systems. The traditional disciplines of engineering are civil, mechanical, electrical, and chemical. The academic discipline of engineering encompasses a broad range of more specialized subfields, and each can have a more specific emphasis for applications of mathematics and science. In turn, modern engineering practice spans multiple fields of engineering, which include designing and improving infrastructure, machinery, vehicles, electronics, materials, and energy systems. For related terms, see glossary of engineering.

As a human endeavor, engineering has existed since ancient times, starting with the six classic simple machines. Examples of large-scale engineering projects from antiquity include impressive structures like the pyramids, elegant temples such as the Parthenon, and water conveyances like hulled watercraft, canals, and the Roman aqueduct. Early machines were powered by humans and animals, then later by wind. Machines of war were invented for siegecraft. In Europe, the scientific and industrial revolutions advanced engineering into a scientific profession and resulted in continuing technological improvements. The steam engine provided much greater power than animals, leading to mechanical propulsion for ships and railways. Further scientific advances resulted in the application of engineering to electrical, chemical, and aerospace requirements, plus the use of new materials for greater efficiencies.

A steam engine is a heat engine that performs mechanical work using steam as its working fluid. The steam engine uses the force produced by steam pressure to push a piston back and forth inside a cylinder. This pushing force can be transformed by a connecting rod and crank into rotational force for work. The term "steam engine" is most commonly applied to reciprocating engines as just described, although some authorities have also referred to the steam turbine and devices such as Hero's aeolipile as "steam engines". The essential feature of steam engines is that they are external combustion engines, where the working fluid is separated from the combustion products. The ideal thermodynamic cycle used to analyze this process is called the Rankine cycle. In general usage, the term steam engine can refer to either complete steam plants (including boilers etc.), such as railway steam locomotives and portable engines, or may refer to the piston or turbine machinery alone, as in the beam engine and stationary steam engine.

Steam-driven devices such as the aeolipile were known in the first century AD, and there were a few other uses recorded in the 16th century. In 1606 Jerónimo de Ayanz y Beaumont patented his invention of the first steam-powered water pump for draining mines. Thomas Savery is considered the inventor of the first commercially used steam powered device, a steam pump that used steam pressure operating directly on the water. The first commercially successful engine that could transmit continuous power to a machine was developed in 1712 by Thomas Newcomen. In 1764, James Watt made a critical improvement by removing spent steam to a separate vessel for condensation, greatly improving the amount of work obtained per unit of fuel consumed. By the 19th century, stationary steam engines powered the factories of the Industrial Revolution. Steam engines replaced sails for ships on paddle steamers, and steam locomotives operated on the railways.

A compound steam engine unit is a type of steam engine where steam is expanded in two or more stages.A typical arrangement for a compound engine is that the steam is first expanded in a high-pressure (HP) cylinder, then having given up heat and losing pressure, it exhausts directly into one or more larger-volume low-pressure (LP) cylinders. Multiple-expansion engines employ additional cylinders, of progressively lower pressure, to extract further energy from the steam.

Invented in 1781, this technique was first employed on a Cornish beam engine in 1804. Around 1850, compound engines were first introduced into Lancashire textile mills.

William McNaught (1813–1881) was a Scottish engineer, from Glasgow, who patented a compound steam engine in 1845. This was a technique of improving the efficiency of a standard simple Boulton & Watt beam engine. The engine was compounded by adding a high-pressure cylinder between the support column and the flywheel, on the side opposite the low-pressure cylinder. This improvement could be retrospectively fitted to existing engines.

Crofton Pumping Station, near the village of Great Bedwyn in Wiltshire, England, supplies the summit pound of the Kennet and Avon Canal with water.

The steam-powered pumping station is preserved and operates on selected weekends. It contains an operational Boulton & Watt steam engine dating from 1812, making it the oldest working beam engine in the world in its original engine house and capable of doing the job for which it was installed.

In a piston engine, a piston rod joins a piston to the crosshead and thus to the connecting rod that drives the crankshaft or (for steam locomotives) the driving wheels.

Internal combustion engines, and in particular all current automobile engines, do not generally have piston rods. Instead they use trunk pistons, where the piston and crosshead are combined and so do not need a rod between them. The term piston rod has been used as a synonym for 'connecting rod' in the context of these engines.