Newcomen Engine (1712): The First Practical Steam Engine

The Newcomen engine, or atmospheric engine, was the first practical steam engine. Built by the Devon ironmonger Thomas Newcomen and erected in 1712 at a coal mine near Dudley Castle in Staffordshire, England, it used steam and air pressure to drive a pump that drew water from deep underground. For more than sixty years it was the only reliable source of mechanical power not dependent on muscle, wind or water, and it opened the way to the steam age.

Background: flooded mines

By the late seventeenth century, British mines for coal, tin and copper were being dug ever deeper, and many were plagued by water. Pumps driven by horses or waterwheels were costly and often could not keep up. Inventors across Europe searched for a way to use fire to raise water.

In 1698 the military engineer Thomas Savery patented a pumping device he advertised as “The Miner’s Friend”. It used steam pressure and condensation directly on the water, without a piston. It was dangerous at high pressure and could lift water only a limited height, so it was of little use in deep mines. Savery’s patent, however, was extended by Act of Parliament in 1699 to run until 1733 and covered any method of raising water by fire.

Thomas Newcomen and John Calley

Thomas Newcomen (1664–1729) was an ironmonger in Dartmouth, Devon, who supplied tools to the tin mines of Cornwall and so knew their problems well. With his partner John Calley, a plumber and glazier, he worked for about a decade on a different design. Little is recorded of these experiments.

Because Savery’s broad patent covered their engine, Newcomen had to work in association with Savery. After Savery’s death in 1715, the rights passed to a group of investors known as the Proprietors of the Invention for Raising Water by Fire, who licensed engines until the patent expired in 1733.

The Dudley Castle engine of 1712

The first securely documented Newcomen engine was erected in 1712 at the Coneygree Coalworks near Dudley Castle, on land belonging to Lord Dudley and Ward. An engraving by Thomas Barney published in 1719 shows the engine in detail and is the main evidence for its design.

The engraving records that the engine made about 12 strokes a minute, each lifting 10 gallons of water from a depth of 51 yards (about 47 metres). That amounts to roughly 120 gallons a minute, a rate that transformed drainage at the pit.

How the atmospheric engine worked

The engine was built around a large rocking beam pivoted on the wall of an engine house:

• The boiler sat beneath a vertical cylinder that was open at the top, with a piston inside.
• The rising stroke: the heavy pump rods hanging from the far end of the beam pulled the piston up, and steam at roughly atmospheric pressure filled the cylinder below it.
• Condensation: a jet of cold water was sprayed into the cylinder, condensing the steam and leaving a partial vacuum.
• The power stroke: the pressure of the atmosphere on top of the piston pushed it down, rocking the beam and lifting the pump rods and water at the other end.

The cycle then repeated. Valves were soon worked automatically by the motion of the beam, so that a single attendant could keep the engine running day and night. Because the cylinder was cooled at every stroke and reheated by the next charge of steam, the engine used a great deal of coal, and its thermal efficiency is usually estimated at well under 1 per cent.

Myths and facts

Newcomen invented the steam engine from nothing. He built on earlier work, including Denis Papin’s experiments with a piston in a cylinder in the 1690s and Savery’s pump. His contribution was to combine a piston, a beam and condensation into a machine that worked reliably for years.

The water jet was a lucky accident. A well-known story, reported by the Swedish engineer Mårten Triewald in 1734, says that Newcomen discovered injection when cold water leaked through a flaw in the cylinder and condensed the steam suddenly. The tale may be true in outline, but it rests on a single later account.

James Watt invented the steam engine. Watt greatly improved an engine that had already been working for about half a century. His separate condenser built directly on Newcomen’s design.

Key people

Thomas Newcomen was a Baptist lay preacher as well as a tradesman, and his religious network in the Midlands may have helped him find his first customers. He never became rich from the engine, largely because of the Savery patent.

John Calley (or Cawley), his partner from Dartmouth, helped build and erect the early engines. Like Newcomen, he left few personal records, so his exact share in the invention is unknown.

Thomas Savery (c. 1650–1715) held the patent that gave him and his successors a share of the profits from every engine built until 1733.

Spread across Britain and Europe

Despite its inefficiency, the engine was ideal for coal mines, where unsaleable small coal could fuel it almost for free. Engines spread quickly through the coalfields of the Midlands, the North East and Scotland, and later to the metal mines of Cornwall, where fuel was more expensive.

Within a few years engines were built abroad, including in the Austrian Netherlands, Hungary, Sweden and France. Historians estimate that hundreds were at work in Britain by the mid-eighteenth century, and well over a thousand had been built by 1800, although figures vary between studies. Ironworks such as Coalbrookdale, where Abraham Darby had pioneered coke smelting, cast cylinders and parts for them.

From Newcomen to Watt

In 1763–1764 James Watt, an instrument maker at the University of Glasgow, was asked to repair a model Newcomen engine. Struck by how much steam it wasted, in 1765 he conceived the separate condenser, in which steam was condensed in a separate vessel so that the main cylinder stayed hot. Watt’s engines, built from 1776 with Matthew Boulton, used far less coal (see James Watt’s steam engine).

Yet Newcomen engines remained in use for decades where coal was cheap, and some were converted rather than replaced. The Elsecar engine near Barnsley, built in 1795, worked until 1923 and is still in its original engine house. A working replica of the Dudley engine was completed at the Black Country Living Museum in 1986.

Timeline

• 1664: Thomas Newcomen is baptised in Dartmouth, Devon.
• 1698: Thomas Savery patents his steam pump for raising water by fire.
• 1699: An Act of Parliament extends Savery’s patent to 1733.
• 1712: Newcomen’s engine is erected at the Coneygree Coalworks near Dudley Castle.
• 1715: Savery dies; the patent passes to the Proprietors.
• 1719: Thomas Barney publishes an engraving of the Dudley engine.
• 1729, 5 August: Newcomen dies in London.
• 1733: The Savery patent expires, opening the engine to all builders.
• 1765: James Watt conceives the separate condenser.

Why it matters

The Newcomen engine was the first machine to turn the heat of burning fuel into useful mechanical work on an industrial scale. By keeping mines dry it helped supply the coal on which British industry came to depend, and it provided the starting point from which Watt and later engineers developed the engines that powered the Industrial Revolution.