Giants of Steam

by Jonathan Glancey

  Newcomen’s engines worked, but they were big and slow and, by the standards of the Stephensons’ much later Rocket locomotive, deeply inefficient. The key problem was that the cylinder was heated and cooled each time the piston was pushed up and then encouraged down, since water was poured into the top of it in order to create the vacuum necessary to prompt the downstroke. Keeping the cylinder warm is essential to the efficiency of a reciprocating steam engine, as engineers were to realize when they finally developed the steam jacket for precisely this purpose.

  The problem was solved by James Watt, the Scottish inventor who by 1765 had transformed Newcomen’s engine into the machine that accelerated the Industrial Revolution to full speed. By creating a cylinder the walls of which stayed warm on both upstroke and downstroke, Watt increased the performance and efficiency of Newcomen’s engine several times over. Watt discovered that no less than 80 per cent of the steam generated in Newcomen’s engines was wasted in heating the cylinder rather than doing useful work. Watt’s patent, ‘A Method for Lessening the Consumption of Steam in Steam Engines – the Separate Condenser’, was first registered in January 1769.

  Although a febrile inventor, Watt was no businessman. It was only when he teamed up with Matthew Boulton, owner of the Soho Foundry, near Birmingham, that he became a wealthy man. Founded in 1794, Boulton & Watt built 1,164 steam engines over the following quarter of a century. Intriguingly, many of these vast machines – some 25 feet high, with cylinders measuring a massive 50 inches in diameter (the largest to be used in a steam locomotive was an exceptional 41 inches, in the United States, in the low-pressure cylinder of John E. Muhlfeld’s two-cylinder, high-pressure, cross-compound 2-8-0 of 1924) – were supported with iron pillars tricked up as Greek and Roman columns. This was not a homage to Hero of Alexandria, but it was an unwitting reference to Vitruvius, who not only described the early steam turbine but also left a body of writing that, when taken up by Italian Renaissance architects, sparked the rise of Neo-Classical design. So while Boulton and Watt were simply reflecting design values of their time, they were nonetheless reinforcing the idea that the steam engine had a classical pedigree.

  What Boulton and Watt did not do was to build a steam locomotive, although they might have been the first to do so. In 1777, William Murdoch, a young Scottish inventor whose reputation had been conveyed to Watt by James Boswell, the biographer of Samuel Johnson, walked more than three hundred miles from his home in Cumnock, East Ayrshire, to Birmingham to ask Watt for a job. Murdoch made many improvements to Boulton & Watt engines, particularly when working in Cornwall, but most importantly he made Britain’s first working model of a steam locomotive. This was intended for the roads rather than rails, but the scale model of a three-wheeler carriage he made in 1784, with the engine slung beneath the two large back wheels, puffed eagerly around his living room in Redruth. This was the first time a man-made machine had travelled under its own steam in Britain.

  Murdoch was aware that the French inventor Nicolas-Joseph Cugnot had got there first with his three-wheeled steam tractors for the army, the first of which moved under its own power in 1769. But, admirable though his achievement was, Cugnot’s steam vehicles were extremely heavy and unstable, had a maximum speed of 4 or 5 mph, and had to stop every fifteen minutes to allow the boiler to recover its working pressure. No one, however, should underestimate the importance of these historic machines and the 1771 model on display at the Musée des Arts et Métiers in Paris is an evocative sight.

  If it had been built to full scale, Murdoch’s road locomotive might have been a spritely machine. Watt, though, believed there was no future in self-propelled road carriages, although Murdoch made a second working model in 1785 and demonstrated it to a wide-eyed public at the King’s Head Hotel in Truro. Watt was also alarmed by Murdoch’s design of a higher-pressure boiler; given the quality of existing materials available for boiler-making, Watt believed in using only atmospheric pressure. While his engines were indeed based to some extent on the principle of a boiling kettle, not wanting to take any undue risk, Watt was wary of the sort of pressures that would be found necessary in the coming years to make a success of the steam railway locomotive. A full-scale working replica of Murdoch’s model was eventually built in Redruth by the Murdoch Flyer Project between 2004 and 2007.

  Murdoch remained an employee of Boulton & Watt, but he kept his models. Sometime in 1797–8, he showed them to Richard Trevithick, the Cornish inventor and mining engineer who was then his neighbour and had seen Murdoch’s first model working under steam in 1784. Trevithick went on to build two steam carriages of his own: Puffing Devil in 1801, and London Steam Carriage in 1803. The following year he created the world’s first steam railway locomotive.

  Any child who finds school difficult should take heart from Trevithick’s story. One teacher from his village school in Camborne reported him as ‘a disobedient, slow, obstinate, spoiled boy, frequently absent and very inattentive’. But the young Trevithick was busy, out and about from school, watching steam pumping engines at work in local mines. Observation, imagination, and a degree of genius allowed Trevithick to develop an engine with a double-acting cylinder, with steam admitted through a four-way valve and exhausted not through Watt’s condenser, but through a chimney. He was getting close to the machinery necessary to make a steam railway locomotive work.

  Next, Trevithick demonstrated a boiler compressed not to Newcomen and Watt’s 14.7 psi but to 145 psi, at which pressure steam forced in and out of double-acting cylinders works hard and powerfully. Trevithick’s bold experiments came to fruition in 1804, assuring him his place in history, while he was working at the Pen-y-Darren Ironworks in Merthyr Tydfil, in South Wales. He mounted a new stationary engine, designed to work a steam hammer, on wheels. Delighted with the ingenuity of the machine, Samuel Homfray, owner of the ironworks, made a bet with a rival ironmaster, Richard Crawshay: fifty guineas said that Trevithick’s (unnamed) locomotive could pull 10 tons of iron along the 9.75 miles of the Merthyr Tydfil tramway from Pen-y-Darren to Abercynon.

  It did. And more. On 21 February 1804, with George III on the throne and Napoleon Bonaparte shortly to be crowned emperor of France, the first railway locomotive hauled not just 10 tons of coal but seventy passengers too, all the way to Abercynon, in four hours and five minutes, at an average speed of 2.4 mph. The locomotive had triumphed, but because of its great weight – 4 tons – it distorted the cast-iron track made for horse-drawn trains. As a result, its wheels were removed and it returned to duty as a steam hammer at Pen-y-Darren. Once a year, a replica steams slowly along a track at the National Waterfront Museum, Swansea.

  The early steam railway locomotive was restricted to use in collieries and ironworks, notably in Cornwall and Northumberland, although in 1808 Trevithick demonstrated a new locomotive, Catch me who can, to the public in a timber-fenced ring laid out in Euston Square. For a shilling a time, Londoners could spot their first steam railway locomotive and ride on a train for the first time. The ‘Steam Circus’ was not as popular as Trevithick hoped it would be. It would be another twenty-eight years before trains and steam locomotives returned to the capital. By then, Trevithick had been three years in his grave. After many failures and a number of hair-raising adventures – in Costa Rica he was very nearly eaten by an alligator – he was engaged to work on the design of an early form of steam turbine for a ship being built by J. & E. Hall Ltd at Dartford in Kent. There he contracted pneumonia and died a pauper in bed at the Bull Hotel on 22 April 1833.

  Between Trevithick’s ‘Steam Circus’ and the opening of the Liverpool & Manchester Railway in 1830, it had been unclear whether or not the steam railway locomotive would take off. Mail coaches, which could average 9 mph from London to what must have seemed like all points of the British compass, and a network of turnpike roads and canals, had revolutionized transport in Britain over the preceding half century. The few steam railway locomotives that existed were slow, lumbering things which led lives well away
from the public gaze. A memoir of the early steam days in the collieries of the North-East written by Thomas Summerside, a friend of the Stephensons, tells how Blücher, an 0-4-0 locomotive built by George Stephenson for the Killingworth colliery in 1814, had a habit of breaking down and could be a pig to start. ( Blücher was named, presumably the following year, after Gebhard Leberecht von Blücher, the Prussian general who came to Wellington’s rescue at the battle of Waterloo in 1815.) George Stephenson would call to his buxom sister-in-law Jinnie, cutting the grass beside the track to feed her cows: ‘Come away, Jinnie, and put your shoulder to her.’ It was her job, too, to get up at the crack of dawn to light Blücher’s fire.

  These first locomotives might have been crude and they were certainly no beauties, yet Trevithick had evidently set something important in motion; his Pen-y-Darren 0-4-0, however, had steamed a little too early in the day to be an economic proposition. The event that set the steam locomotive on its untrammelled metal course around the world was the Rainhill Trials of October 1829. Here was the opportunity for George Stephenson, and his son Robert, to prove that a steam locomotive could be fast, exciting, and attractive. Rocket, a canary-yellow and white 0-2-2, was a pretty machine, a locomotive wholly unlike its crudely presented predecessors, whether on the Stockton & Darlington Railway or working collieries and ironworks. Rocket was designed for passenger service. During the Rainhill Trials some fifteen thousand people saw Rocket, and its rivals, in action.

  The Rainhill Trials determined what type of traction would haul the trains of the Liverpool & Manchester Railway, the world’s first intercity service. There was no guarantee that locomotives would win the day. The answer might have been rope haulage with a succession of stationary steam engines pulling trains between the two Lancashire cities. Rocket, though, was a new type of locomotive. Her boiler contained not a single large flue, with a fire at one end to heat the water and raise steam, but, at the suggestion of Henry Booth, the scientifically minded treasurer of the Liverpool & Manchester Railway, twenty-five small copper flues, or tubes, which would greatly increase the boiler’s surface area and hence both the quantity and rate of steam produced. This coincided with the first application of a multi-tubular boiler in France, by Marc Seguin. A separate copper fire-box was fitted to the back of Rocket’s boiler. A blast-pipe exhausting steam from the cylinders created a vacuum drawing heat from the fire and through the boiler tubes.

  The completed locomotive, with its boiler tested to 70 psi (its working pressure was 50 psi), was disassembled and packed off by horse and cart from Newcastle to Carlisle, and then by canal lighter to Bowness-on-Solway, where the crates were loaded on to a boat to Liverpool, the journey taking the best part of six days. Rocket ran very well indeed and easily won the Rainhill Trials. Eight further members of the class were built in time for the public opening of the Liverpool & Manchester Railway in September 1830. The later locomotives featured water-jacketed fire-boxes, considerably increasing steam production, smoke-boxes to collect unburned fuel and char through the boiler tubes, and cylinders mounted close to the horizontal (Rocket’s were angled at 45 degrees) to provide smoother movement with less stress on the track – Rocket had tended to waddle along. Capable of at least 36 mph, these Stephenson machines launched not just the steam locomotive in public service, but the very idea of the trunk railway rushing passengers from city to city.

  Just three years later, a locomotive emerged from the works of Robert Stephenson which is largely forgotten but remains key to the story of the steam railway. This was Patentee, an inside-cylindered 2-2-2, designed for service on the Liverpool & Manchester Railway, the Grand Junction Railway connecting Manchester and Birmingham, and other new railways which were springing up as fast as parliament could pass acts in their favour. Its design set the style and general arrangement of thousands of British locomotives built over the next century. With a more effective blast-pipe in the smoke-box channelling exhaust steam from the cylinders and mixing it with combustion gases drawn through the boiler tubes as a result of the vacuum, Patentee was a major advance on Rocket. Patentee’s cylinders were inside the frames and under the smoke-box to keep them warm, minimizing condensation losses and increasing efficiency, and allowing the engine to run more smoothly than Rocket’s due to better balancing of the driving forces.

  If Patentee had a fault – as did so many of these early locomotives – it lay in the fact that her construction was disharmonious. These were truly early days: not only was the steam locomotive new, but the materials used in its construction were still largely untested, especially in the rough and tumble of regular everyday passenger and goods services over long distances, uphill and down. Many locomotives of this generation would virtually shake themselves to pieces, suffering severe vibratory stresses and fractured components which entailed frequent repairs. Their lives were short, if colourful. Yet half a century on, British 2-2-2 and 4-2-2 locomotives – descendants of Stephenson’s Patentee – were running at speeds of up to 90 mph and clocking up mileages of over a million miles before being withdrawn from service. All the great steam locomotive engineers of the future would possess a very sound understanding of materials – just as they all served long apprenticeships, beginning with the making of bolts and screws, before they were let anywhere near the drawing board.

  Even so, something was missing in the 1830s to make the Stephensonian locomotive a world-beater. This was the reversing link motion, invented in 1842 by William Howe, a pattern-maker with the Robert Stephenson works in Newcastle-upon-Tyne. Howe’s invention, known as Stephenson’s Link Motion, allowed the driver progressively to cut off steam admission into the cylinders. While a locomotive often needs the full force of steam rushing into the cylinders to get a train moving, or to climb a severe gradient, it needs far less steam once it is up to speed. Howe’s lever-controlled motion linkage meant that the driver could choose the percentage of piston stroke during which steam would be admitted to produce the required power. When starting, he might admit steam for 75 or even 80 per cent of the piston stroke; as the train accelerated he could ‘link up’ or ‘notch up’ so that the volume of steam admitted to the cylinders per stroke was progressively reduced. The most efficient steam locomotives might streak along with an express passenger train on level track at full regulator and yet with a ‘cut-off’ of as little as 15 or even 10 per cent, with much of the power being developed from the steam that had been admitted expanding in the cylinders. Howe’s invention gave the steam locomotive the equivalent of the gears used in a car. A cut-off of 75 per cent is rather like being in first gear, 50 per cent second, 35 per cent third, and so on. Rewarded by Robert Stephenson with a bonus of twenty guineas, Howe saved railway companies huge amounts of money as fuel bills fell when their drivers were trained to run well ‘linked up’.

  Now, four of the five fundamental engineering characteristics of the classic Stephensonian locomotive had been established. The five components were like five commandments, forged in iron and handed down from Robert Stephenson and Company in Newcastle-upon-Tyne to drawing offices and engineering workshops in Britain and around the world. These commanding characteristics were as much a part of Evening Star, the last main-line locomotive to be built for regular service in Britain, as they were of Stephenson engines of a century and a half earlier. They were: (i) two cylinders with cranks at right angles, unless power requirements called for three or four cylinders; (ii) the blast-pipe exhaust, giving induced draught to force the fire to produce the heat necessary for the required steam production; (iii) the multi– tubed boiler with separate fire-box; (iv) expansion valve motion; and (v), the one major characteristic that nineteenth-century locomotives lacked, the smoke-tube superheater, a device that would eliminate cylinder condensation when a locomotive was on the move and would greatly increase the volume and effectiveness of steam at any given pressure, increasing power by 20 to 25 per cent.

  Over the following sixty years, between Howe’s link motion for Robert Stephenson and George
Churchward’s appointment as locomotive superintendent at the GWR, many thousands of steam locomotives were built in Britain, and then in Europe, the United States, and, more slowly, in other parts of the world, which rarely differed from the pattern of design set in those pioneering days. National and regional characteristics emerged, with such distinctive designs as the all-purpose American 4-4-0, with its prominent cowcatcher, bulbous chimney stack designed to catch (or ‘arrest’) sparks, outside cylinder drive, powerful headlamp, sonorous bell, and mournful whistle; French locomotives, covered in ancillary equipment of all sorts intended to increase their efficiency; and the classic Victorian British locomotive, shaped – oh so elegantly – as if it had no moving parts whatsoever, galloping through the landscape like a thoroughbred hunter.

  Despite outward appearances, design changes came slowly and steadily in the second half of the nineteenth century, rather than in a rush. This is understandable, given that few railways demanded great speeds until the twentieth century, and that most passenger trains were very light before the advent of corridor-connected, double-bogie carriages, restaurant cars, kitchens, lavatories, air conditioning, and other conveniences and luxuries. It is also true that, for the most part, labour – even skilled labour – was cheap and, until trade unions developed muscle, management was able to rule the railway roost on its own terms.

  Cheap and plentiful labour also meant that nineteenth-century steam locomotives tended to be beautifully turned out, immaculate in their astonishing variety of liveries, from cream, through Stroudley’s improved engine yellow, Brunswick green, Prussian blue, and crimson lake, to the glossiest blackberry black. This must surely have been one reason why the steam locomotive, and the steam railway as a whole, won admiration so very quickly from the wider public. From the ungainly, smoke-belching monsters of the colliery days before the Liverpool & Manchester Railway, the steam locomotive had turned into the most elegant and prized machine.