Full Steam Ahead: How the Railways Made Britain. Peter Ginn
engines were prone to exploding, with catastrophic and often fatal consequences, but it was clear to everyone within the mining and engineering community that steam power was the way forward. After several people had made improvements to Savery’s invention, the next major leap came in 1712, when Thomas Newcomen devised a beam engine that could drive a piston. The five horsepower that Newcomen’s engine could produce more than doubled the power of the Savery engine, and this machine proved to be altogether a much safer beast. It would be this engine that transformed mining capabilities across the country and which so intrigued and inspired James Watt around fifty years later.
“AS A CHILD, JAMES WAS REPORTED AS ENJOYING NOTHING MORE THAN TAKING HIS TOYS APART AND PUTTING THEM BACK TOGETHER.”
In the late eighteenth century, Glasgow University was a forward-looking institution, interested in and supportive of many different kinds of scientific investigation. So perhaps it comes as no surprise that it should have owned a working model of a Newcomen engine. However, for ‘working’, read ‘broken’… Attempts to repair the model in London appeared to be going nowhere, so the engine was returned to Glasgow and was handed over to James Watt. The model revealed several shortcomings to Watt and sent him off on a furious search through the scientific literature of the day. However, since much of that literature was not in the English language, he had first to learn French, Italian and German before he could decipher a lot of key information. Watt might well have disliked business – ‘I would rather face a loaded cannon than settle an account or make a bargain’ – and had indeed been involved in several business failures, but he was nonetheless an incredibly inventive and driven man who was unafraid of hard intellectual as well as physical work. By several accounts, James Watt was also a pleasant man to be around; for example, his workshop at the university became a popular place for academics, engineers and others to gather and socialize. Combining all he had learnt from the scientific papers and from the model of Newcomen’s engine, Watt began to investigate the theory of ‘latent heat’. At this time, he discovered that another man at the university, Professor Robert Black, had already come up with the theory and had even been teaching it for several years. Some lesser men might have given up at that point, but Watt was not a man of petty jealousies; neither was Robert Black, and so the pair teamed up.
“WHEN PEOPLE SAY ‘JAMES WATT INVENTED THE STEAM ENGINE’, THEY MEAN HE WAS THE FIRST TO COME UP WITH THE IDEA OF CONDENSING STEAM.”
James Watt improved Thomas Newcomen’s basic design in 1769, with a more efficient engine featuring a cylinder that stayed hot.
When people say ‘James Watt invented the steam engine’, what they mean is that he was the first to come up with the idea of condensing the steam in a separate chamber. Born out of his hard-won understanding of latent heat, he could see that Newcomen’s engine lost most of its power re-heating the cylinder after each stroke. Newcomen’s piston was driven when hot steam pushed in one direction, a spray of cold water cooled the steam, and the piston was drawn back by the resultant vacuum. However, each cooling cycle cooled not only the steam but the cylinder, too. Watt realized that the now cool cylinder was drawing much of the potential energy of the steam, simply to reheat it on every stroke, making Newcomen’s engine supremely inefficient. Having identified and analysed the scientific problem, Watt then had to find a way of solving it mechanically. Many of his early attempts were dogged by the difficulty of getting truly precision parts made. The theory and designs were basically right in principle, but the skill levels of many of the workmen he had to rely on sometimes let him down.
James Watt was a powerful innovator, whose great expertise lay in analyzing and adapting the technical ideas and developments of other engineers.
It would take many years of hard slog, further technical insight and invention to sort out the technical difficulties of full-scale production. Watt’s major backer and business partner during this period was Joe Roebuck, who owned the Carron colliery and had the foresight to see that steam-powered engines were the way forward. However, the development of Watt’s engine took more time and money than Joe Roebuck’s business could support. Consequently, Watt had to abandon full-time developmental work and work as a surveyor – a job that he hated – and Joe Roebuck, faced additionally with a small economic downturn, went bankrupt. That might well have been that – and James Watt could well have remained a footnote in history – if not for another example of different skills, ideas and histories coming together at the optimum moment.
Once he became bankrupt, Joe Roebuck’s share in Watt’s steam engine was bought out by one Matthew Boulton. Boulton was not an engineer, but rather a businessman – perhaps the first great businessman, a man who could be said to have invented the production line. He ran one of the largest factories in the world at Soho in Birmingham, and was a genius at marketing, networking and financial control. He was also hugely rich. With money, and the efforts of plenty of skilled (and more disciplined) workers and customers organized by Boulton, the first of Watt’s rotary motion ten horsepower pressurized steam engines went into production in 1781. Steam power was no longer largely confined to pumping water out of mines – Boulton and Watt’s engines, capable of providing a steady powered spinning motion, could be turned to a vast array of industrial processes. From hereon in, steam began to revolutionize a host of different businesses. It was Boulton rather than Watt who had seen the importance of rotary motion and how it could be successfully employed.
LOCOMOTIVES
Let us return to the Ffestiniog railway by way of the early steam engines, Puffing Billy and The Rocket. In 1832, as they launched their railway building project, Holland and Archer could conceivably have chosen to employ steam power, either from a static engine that could haul wagons up and down small inclines on the end of a rope or chain, or from a true steam locomotive. However, neither option would have seemed to be a particularly attractive proposition at that precise moment. The slate business enjoyed the benefit of only needing to transport their heavy wares down from the mountainside to the docks, so that exclusively empty, lighter wagons needed to make the journey back up. Consequently, a static engine designed to haul wagons back up inclines was unnecessary, so long as the wagons could be made light enough for a horse to do the job. As for a steam locomotive – well, in 1832 there was no narrow-gauge engine available that was strong enough to perform the role.
On 29 October 1804 at Pen-y-darren ironworks, Merthyr Tydfil, a self-propelled steam engine made its way along the iron railway towards Abercynon. The anonymous locomotive had been built by Richard Trevithick, who was well established as a steam engineer and had worked out a method of using pressurized steam that obviated the need for Watt’s separate condenser. Trevithick adopted this approach, as he did not want to have to pay a licence fee for the use of Watt’s patented device. Trevithick had experimented two years previously at Pen-y-darren, with the support of the owner and the assistance of Rees Jones, who was an employee of the ironworks. However, the 1804 run does not appear to have been a serious attempt to launch steam locomotion, but rather was staged to win a bet. A large crowd gathered to see the locomotive pull five wagons with ten tons of coal and seventy men the full nine and three quarter miles at walking pace. The bet was won, but the heavy engine broke the iron-topped wooden rails and was immediately retired from action. However, with so many people watching and with such an important name as Trevithick involved, it was not long before many other engineers began experimenting with locomotives.
Presenters Ruth Goodman, Alex Langlands and Peter Ginn on the Ffestiniog railway in north Wales.
Richard Trevithick (1771–1833) was a Cornish inventor and mining engineer. His work built on that achieved by Watt and advanced the new science of steam locomotion.