Newcomen Engine

c1791. Newcomen-type engine built in Derbyshire by Francis Thompson (1747-1809). Exhibit at the London Science Museum.

c1712.

c1712.

1917. Fairbottom Bobs Newcomen engine near Ashton-under-Lyne.

1931. Fairbottom Bobs Newcomen Engine re-erected in the Dearborn Museum.

1729. Engraving by Switzer

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1933. Newcomen Engine of 1746.

The 'atmospheric engine' invented by Thomas Newcomen and John Calley, today referred to as a Newcomen engine, was the first device to harness the power of steam to produce mechanical work for practical application.

General

See Wikipedia entry for an animation showing the operating cycle of the Newcomen engine.

Newcomen engines were used throughout Britain and Europe principally to pump water out of mines, starting at the beginning of the 18th century. The magnitude of Newcomen and Calley's achievement at that early date cannot be overstated. Over half a century would elapse before any fundamental improvement was implemeted commercially.

James Watt took Newcomen's engine as the basis for developing improved steam engines. Although Watt is far more famous today, Newcomen deserves the first credit for the widespread introduction and acceptance of steam power. Credit must also be given to other steam engine inventors who diverged from the 'atmospheric' principle. One of the most remarkable was Nicholas Joseph Cugnot, who was probably the first to produce a working non-condensing steam engine.

Prior to Newcomen starting his development work, a number of small steam-powered devices of various sorts had been built, but most were essentially novelties. Around 1600 a number of experimenters used steam to power fountains, first filling a container with water, then pressurising it with steam to force it out.

In 1662 Edward Somerset, 2nd Marquis of Worcester, published a book containing several ideas he had been working on. One was a contrivance for raising water from a closed vessel, by admitting steam to the top of the vessel.

Several other experimenters investigated the use of steam to do mechanical work. One of the most interesting was that of Denis Papin, who succeeded in raising a piston by boiling water in a cylinder, and showed that the vacuum created when the steam condensed could lift a heavy weight. He failed to develop it for practical application, but it represents an important stepping stone on the way to the development of the steam engine.

In 1698 Thomas Savery patented his 'fire engine', a steam powered pump he called the Miner's Friend, applied to pumping out mines. Steam was admitted to a sealed container and then condensed by cooling the outside of the vessel with water. The vacuum thus created was used to draw water from the sump at the bottom of the mine. The process of cooling and creating the vacuum was fairly slow. The lift to the vessel was limited by atmospheric pressure to about thirty feet, but Savery contrived to use steam pressure to then lift water above the vessel. However, the problems of dealing with steam at any useful pressure may have been insurmountable, and would in any case be attended by considerable danger (especially in the absence of a safety valve). Further, it would seem that difficulties would arise because the cold vessel would initially cool the incoming steam, and, more significantly, the water would tend to rapidly condense the incoming steam, and would readily do so if the surface of the water were appreciably disturbed by the incoming steam. This would waste steam and prolong the operating cycle. Nevertheless, Savery did construct and operate such pumps. He has left us descriptions of their operation, and of the phenomena which indicated the sequences (heating and cooling of the vessels, the appearance of dry and wet surfaces on the pressure/vacuum vessels, rattling of the non-return valves, etc).

When Denis Papin learned about Savery's engine he envisaged problems due to condensation when the steam encountered the cold water, and he proposed to address the phenomenon by introducing a piston floating on the surface. He published details of his proposed pump in 1707. In fact the problem of condensation and heat loss arising from contact between the forcing steam and the water, anticipated by Papin, seems not to have been a major obstacle needing to be overcome. In the Pulsometer, a Savery-type pump patented by Charles Henry Hall in 1872, steam acted directly on the water without the intervention of a piston.

Savery called his invention an 'engine', but it could not transmit its power to any external device. There were evidently high hopes for the Miner's Friend, which led Parliament to extend the life of the patent by 21 years, so that the 1699 patent would not expire until 1733. Unfortunately, Savery's device proved much less successful than had been hoped.

Because of the limited lift, and the dangers and practical difficulties associated with Savery's pump working at higher lifts, some sort of mechanical pump remained the only option for deep mines, one that lifted the water directly instead of "sucking" it up. Such pumps were common already, but required a vertical reciprocating action that Savery's system did not provide.

Newcomen may well have been influenced by Papin's demonstration of the use of steam condensed in a cylinder to raise a weight. In fact it is difficult to imagine that he was unaware of it. Equally, he would surely be aware of Savery's work, although we do not know when Newcomen first embarked on his deliberations. Stephen Switzer, writing in 1729, stated that Newcomen was as early in his invention as Mr. Savery.. Swedish engineer Marten Triewald, writing in 1734 after residing in England between 1716 and 1726, stated that Newcomen had no knowledge whatever of the speculations of Captain Savery. Apparently contradicting this is a claim that in 1705 a patent was granted to Thomas Newcomen, John Calley and Thomas Savery for an engine in which steam was introduced under a piston and condensed, and reciprocating motion was produced by attaching it to a lever! . However, Rhys Jenkins stated in 1923 that no evidence of such a patent had been found .

Although much has been written about the extent to which Newcomen and Calley may have been influenced by the work of others, the fact remains that Newcomen and Calley succeeded in producing practical working engines that proved to be essential factors in the Industrial Revolution. The concept seems simple and obvious through modern eyes, but a considerable amount of hard work, ingenuity, luck, metalworking knowledge and skilled craftsmanship were needed to take the atmospheric engine from an attractive concept to a commercial reality as a self-acting pumping engine.

It appears that Newcomen and Calley's first large engine was installed at Balcoath in Cornwall. 'It is said that the steam-engine was first employed in working at Balcoath, in Wendron, and at Great Wheal Vor, and steam is supposed to have been raised from burning turf. The engine was worked by five lifts down to the 50 or 60 fathoms level: five holes were bored in the sollar through which five rods were worked.

Newcomen and Calley must have spent a considerable amount of time in carrying out experiments before committing to installing the engines in Cornwall, but nothing seems to be known. There were numerous problems to be discovered and resolved, logisitic matters to be addressed (not least of which was the procurement of suitable cylinders), dimensions to be determined (for example, how big did the cylinder and boiler need to be?).

James Greener suggests that the Balcoath engine's brass cylinder, of c.16-inch diameter, was removed to the Conygree Coalworks near Dudley in late 1710, to construct an engine to pump out the water-filled coal mine. Newcomen then proposed to replace this with a new engine having a 22-inch cylinder. The cylinder was probably cast by Richard Saunders of Bromsgrove, a bell-founder. The 16-inch engine was probably then moved to William Bache's New Mine shaft at Stow Heath.

A full-size working replica can today be seen at the nearby Black Country Living Museum, which stands on another part of what was Lord Dudley's Conygree Park.

Soon orders from wet mines all over England were coming in, and some have suggested that word of his achievement was spread through his Baptist connections.

As Savery's patent had not yet run out, Newcomen operated under that patent, since its term was much longer than any Newcomen could have easily obtained. During the latter years of its currency, the patent belonged to an unincorporated company, The Proprietors of the Invention for Raising Water by Fire, whose members included John Meres.

By the time of his death, Newcomen and others had installed over a hundred of his engines, not only in the West Country and the Midlands but also in north Wales, near Newcastle and in Cumbria.

Newcomen engines were ill-suited to providing rotary motion, partly due to the single power stroke. Despite Watt's improvement, Common Engines (as they were then known) remained in use for a considerable time. Probably the last Newcomen-style engine to be used commercially — and the last still remaining on its original site — is at Elsecar, near Barnsley in South Yorkshire.

Remarkably, a Newcomen-type engine was built as late as 1810/11 for Farme Colliery. Remarkable, too, is the fact that it was used for the exacting duty of colliery winding.

Overseas

The first Newcomen engine on the Continent was erected in 1721-2 by Isaac Potter and Joseph Emanuel Fischer.

The first Newcomen engine in France was installed by John May and John Meres (referred to as John Meyer in France) in 1726. A Newcomen engine installed by the Compagnie d’Anzin at Fresnes in the early 1730s was built by Christophe Mathieu, based on examples installed at Liège and Charleroi in the late 1720s.

The first Newcomen engine in the Americas was erected by Josiah Hornblower. It was shipped from England in 1753 and started work in 1755.

Technical details

Newcomen's engine had a boiler in which the steam was generated, usually of the 'haystack' type, situated directly below the cylinder. It produced low pressure steam, all that the current state of boiler construction could cope with.

One side of the beam was attached by a chain to the pump located at the base of the mine, and the chain at the other side suspended a piston within a cylinder. The cylinder was open at the top end, above the piston, to the atmosphere. Early engines had the piston sealed by a leather cup seal. Later a rope seal was used, kept in place by metal weights. In all cases, additional sealing was provided by a film of water maintained on top of the piston.

By opening a valve, steam was admitted from the boiler into the cylinder. After closing the steam valve, a valve was opened to allow water from the water tank to be sprayed into the cylinder, thus condensing the steam and collapsing the pressure under the piston. The use of sprayed water was one of Newcomen and Calley's key discoveries which made the concept viable. The atmospheric pressure above then pushed the piston down in the power stroke. This raised the working parts of the pump. Their weight returned the beam to its original position when the vacuum decayed and steam was readmitted. The steam drove out the condensate (and the air and other gases liberated from the steam and the spray water) through a one-way 'snifting valve' as the process started all over again.

The earliest versions apparently used manual operation of the valves, but the action was slow enough that this was not a serious concern. Later versions used controls attached to the rocking beam to open and close the valves automatically when the beam reached certain positions. The common myth is that in 1713 a boy named Humphrey Potter, whose duty it was to open and shut the valves of an engine he attended, made the engine self-acting by causing the beam itself to open and close the valves by suitable cords and catches (known as the "potter cord"). The arrangement was simplified by 1718 according to an illustration by Henry Beighton, who showed suspended from the beam a rod called the plugtree, which worked the valves by means of tappets.

By 1725 the engine was in common use in collieries, and it held its place without major change for about three-quarters of a century. Towards the close of its career the atmospheric engine was much improved in its mechanical details by John Smeaton, who built many large engines of this type.

While its main use was pumping water out of mines, the Newcomen engine was also used in some places to pump water to drive machinery, for example refilling the upper pool at Coalbrookdale so that there was more water available to drive the blast furnace blowers, also at Madeley Wood or Bedlam Furnaces and others of the same period in the 1750s. Richard Arkwright, for example, even attempted to use a Newcomen engine to pump water to power a waterwheel.

The main problem with the Newcomen design was that it was very expensive to operate. The injected water caused some cooling of the cylinder walls and piston, which condensed some of the steam as it was admitted. This meant that a considerable amount of fuel was being used just to replace this heat loss. As the heat losses were related to the surfaces, while useful work related to the volume, increases in the size of the engine increased efficiency. Newcomen engines became larger in time. However, efficiency was a secondary consideration within the context of a colliery, where coal was readily available, and unsaleable coal could be used. Attempts were made to drive machinery by Newcomen engines, but these were unsuccessful, as the single power stroke produced a very jerky motion.

From the early 1760s James Smeaton, by careful experimentation and attention to detail, was able to effect considerable reductions in steam consumption.

Newcomen's engine was superseded by developments initiated by James Watt. Watt had been asked to repair a model of a Newcomen engine by Glasgow University. A small model greatly exaggerated the scale problem of the Newcomen engine, and led him to contemplate improvements. Watt's first improvement was to effect the condensation in a separate container, attached to the steam cylinder via a pipe. When a valve on the pipe was opened, the vacuum in the condenser would, in turn, evacuate that part of the cylinder below the piston. This eliminated the heating and cooling of the main cylinder, and dramatically reduced fuel use. Watt also introduced double-acting engines. His improvements led to the wider acceptance of reciprocating engines: upward and downward power strokes were more suited to transmitting power to a wheel. Additionally the use of positive (albeit very low) steam pressure helped with controllability.

Watt's design, introduced in 1769, did not eliminate Newcomen engines immediately. Watt's vigorous defence of his patents resulted in the desire to avoid royalty payments as far as possible. The expiry of the patents led to a rush to install Watt engines in the 1790s, and Newcomen engines were eclipsed - even in collieries. Probably the last Newcomen-style engine to be used commercially – and the last still remaining on its original site – is at Elsecar, near Barnsley in South Yorkshire.

Notes

The Newcomen Memorial Engine can be seen in Dartmouth, home of Thomas Newcomen at The Engine House, Mayors Avenue, Dartmouth, Devon, TQ6 9YY. See the 'Discover Dartmouth' Newcomen Engine webpage for more details.

Eric Preston writes on 27th February 2012: Newcomen Engine - please see my recent booklet on 'Thomas Newcomen of Dartmouth', by Eric Preston. ISBN 1-899011-27-7, available from Dartmouth Tourist Information Centre. The first successful Newcomen Engine was in 1712 at Conygree, it is thought the Wolverhampton one was never actually installed in 1711. The Newcomen Memorial Engine at Dartmouth dates from 1725 and was moved there in 1963. this can be seen operating, but not with steam.

Series of Articles Published in The Engineer

Below are the links to the articles on the Newcomen Engine as published in The Engineer in 1879.

• (No. I)  : The Engineer 1879/06/06.
• (No. II) : The Engineer 1879/06/13.

See Also

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