Thomas Newcomen

The Steam Engines of Thomas Newcomen

Thomas Newcomen's engine
Illustration of steam train and smaller images of Rocket steam locomotive and mechanism of Thomas Newcomen's engine. (Getty Images)

Who was the man who put together the prototype for the first modern steam engine? It was Thomas Newcomen a blacksmith from Dartmouth, England and the engine invented by him in 1712 was known as the "Atmospheric Steam Engine".

Before Thomas Newcomen's time, steam engine technology was in its infancy. Inventors, Edward Somerset of Worcester, Thomas Savery, and John Desaguliers were researching the technology before Thomas Newcomen begin his experiments, their research inspired inventors Thomas Newcomen and James Watt to invent practical and useful steam-powered machines.

Thomas Newcomen & Thomas Savery

Not much is known about the personal history of Thomas Newcomen. The inventor was considered an eccentric and a schemer by locals. However, Thomas Newcomen did know about the steam engine invented by Thomas Savery. Newcomen visited Savery's home in Modbury, England, fifteen miles from where Newcomen lived. Thomas Newcomen was hired by Savery for his blacksmithing and iron-forging skills, to forge for Savery's engine. Newcomen was allowed to make a copy of the Savery machine for himself, which he set it up in his own backyard, where he worked on improving the Savery design.

Thomas Newcomen & John Calley

Thomas Newcomen was assisted by John Calley in his steam research, the two inventors are listed on the patent for the Atmospheric Steam Engine.

Thomas Newcomen and John Calley were both uneducated in mechanical engineering and corresponded with scientist Robert Hooke asking him to advise them about their plans to build a steam engine with a steam cylinder containing a piston similar to that of Denis Papin's.

Hooke advised against their plan, but, fortunately, the obstinate and uneducated mechanics stuck to their plans.

Thomas Newcomen and John Calley built an engine that while not a total success, they were able to patent in 1708. It was an engine combining a steam cylinder and piston, surface condensation, a separate boiler, and separate pumps.

Also named on the patent was Thomas Savery who at that time held the exclusive rights to use surface condensation.

Progress of the Atmospheric Steam Engine

The atmospheric engine, as first designed, had a slow process of condensation by the application of the condensing water to the exterior of the cylinder, to produce the vacuum, caused the strokes of the engine to take place at very long intervals. More improvements were made, which immensely increased the rapidity of condensation. Thomas Newcomen's first engine produced 6 or 8 strokes a minute and he improved that to 10 or 12 strokes.

Photo of Thomas Newcomen's Atmospheric Steam Engine

In the photo listed above - a boiler is depicted. Steam passes from it through the cock, and up into the cylinder, equilibrating the pressure of the atmosphere, and allowing the heavy pump rod, to fall, and, by the greater weight acting through the beam, to raise the piston, to the position shown. The rod carries a counterbalance if needed. The cock being shut is then opened, and a jet of water from the reservoir, enters the cylinder, producing a vacuum by the condensation of the steam. The pressure of the air above the piston now forces it down, again raising the pump rods, and thus the engine works on indefinitely.

The pipe is used for the purpose of keeping the upper side of the piston covered with water, to prevent air leaks­ an invention of Thomas Newcomen. Two gauge-cocks and a safety valve are represented in the photo. Here, the pressure used was hardly greater than that of the atmosphere, and the weight of the valve itself was ordinarily sufficient to keep it down. The condensing water, together with the water of condensation, flows off through the open pipe.

Public Reception to the Thomas Newcomen Engine

At first, Thomas Newcomen's steam engine was seen as a rehash of earlier ideas. It was compared to a piston engine powered by gunpowder, designed (but never built) by Christian Huyghens, with a substitution of steam for the gasses generated by the explosion of gunpowder. It was later recognized that Thomas Newcomen and John Calley had improved the method of condensation used in the Savery engine.

Thomas Newcomen's Steam Engine Put to Work in the Mines

Thomas Newcomen modified his steam engine so that it could power the pumps used in mining operations that removed water from mine shafts. He added an overhead beam, from which the piston was suspended at one end and the pump rod at the other.

Inventor John Desaguliers Wrote The Following About Thomas Newcomen

"Thomas Newcomen made several experiments in private about the year 1710, and in the latter end of the year 1711 made proposals to drain the water of a colliery (mine) at Griff, in Warwickshire, where the proprietors employed 500 horses, at an expense of £900 a year; but, their invention not meeting with the reception they expected, in March following, through the acquaintance of Dr. Potter, of Bromsgrove, in Worcestershire, they bargained to draw water for Mr. Back, of Wolverhampton, where, after a great many laborious attempts, they did make the engine work; but, not being either philosophers to understand the reason, or mathematicians enough to calculate the powers and proportions of the parts, they very luckily, by accident, found what they sought for.

They were at a loss about the pumps, but, being so near Birmingham, and having the assistance of so many admirable and ingenious workmen, they came, about 1712, to the method of making the pump valves, clacks, and buckets, whereas they had but an imperfect notion of them before. One thing is very remarkable: as they were at first working, they were surprised to see the engine go several strokes, and very quick together, when, after a search, they found a hole in the piston, which let the cold water in to condense the steam in the inside of the cylinder, whereas, before, they had always done it on the outside.

They used before to work with a buoy to the cylinder, enclosed in a pipe, which buoy ​rose  [sic.] when the steam was strong and opened the injection, and made a stroke; thereby they were only capable of giving 6, 8, or 10 strokes in a minute, till a boy, named Humphrey Potter, in 1713, who attended the engine, added a scog or a catch, that the beam always opened, and then it would go 15 or 16 strokes a minute. But, this being perplexed with catches and strings, Sir Henry Beighton, in an engine he had built at Newcastle upon Tyne in 1718, took them all away but the beam itself, and supplied them in a much better manner."

In illustration of the application of the Thomas Newcomen engine to the drainage of mines, Farey describes a small machine, of which the pump is 8 inches in diameter, and the lift 162 feet. The column of water to be raised weighed 3,535 pounds. The steam piston was made 2 feet in diameter, giving an area of 452 square inches. The net working pressure was assumed at 10 pounds per square inch; the temperature of the water of condensation and of uncondensed vapor after the entrance of the injection water being usually about 150° Fahr. This gave an excess of pressure on the stream side of 1,324 pounds, the total pressure on the piston being 4,859 pounds.

One-half of this excess is counterweighted by the pump rods, and by weight on that end of the beam; and the weight, 662 pounds, acting on each side alternately as a surplus, produced the requisite rapidity of movement of the machine. This engine was said to make 15 strokes per minute, giving a speed of piston of 75 feet per minute, and the power exerted usefully was equivalent to 265,125 pounds raised one foot high per minute. As the horsepower is equivalent to 33,000 " foot pounds " per minute, the engine was shed almost exactly 8 horsepower.

It is instructive to contrast this estimate with that made for a Savery engine doing the same work. The latter would have raised the water about 2G feet in its " suction pipe," and would then have forced it by the direct pressure of steam, the remaining distance of 13G feet; and the steam pressure required would have been nearly 60 pounds per square inch.

With this high temperature and pressure, the waste of steam by condensation in the forcing vessels would have been so great that it would have compelled the adoption of two engines of considerable size, each lifting the water one-half the height, and using steam of about 25 pounds pressure. Potter's rude valve gear was soon improved by Henry Beighton, in an engine which that talented engineer erected (Newcastle upon Tyne in 1718), and in which he substituted substantial materials for the cords.

After the death of Beighton, the atmospheric engine of Thomas Newcomen retained its then standard form for many years, and came into extensive use in all the mining districts, particularly in Cornwall, and was also applied occasionally to the drainage of wetlands, to the supply of water to towns, and it was even proposed by Hulls to be used for ship propulsion.