Railroads England - George Stephenson's Locomotives
( Originally Published 1927 )
The Wylam wagon-way passed close in front of the cottage in which George Stephenson was born and one of the earliest sights with which his eyes became familiar was that of the coal-wagons being drawn by horses along the wooden tram-road. The boy, born in 1781, was early employed in the colliery ; he was eighteen years old before he learned to read, at which time he was earning twelve shillings a week and had charge of an engine in the mine, which occupied him twelve hours a day. A sober, steady, and expert work-man, he managed to lay aside enough money to en-able him to marry and establish a home of his own at Willington Quay, where he was engaged as brakes-man at the Ballast Hill, on the north bank of the Tyne, about six miles below Newcastle. Here his son Robert was born in 1803. From Willington he moved to the West Moor Colliery at Killingworth, and it was there that his remarkable ability as an engineer and inventor began to attract the attention of the mine owners.
While Blackett at Wylam was experimenting with locomotives George Stephenson at Killingworth was studying the same problems. He had already made one important improvement in the colliery machinery; by applying the surplus power of a pumping steam-engine, stationed in the mine, to the drawing of coal up from the deeper workings he had effected a large reduction in the expenditure on manual and horse labor. He then sought some simplification of the method of hauling the wagons, and for this purpose laid down inclined planes where the nature of the ground would permit. A train of filled wagons was let down the incline by means of a rope that ran over wheels placed along the tram-road, the other end of the rope was attached to a train of empty wagons placed at the bottom of the parallel road on the same incline and dragged them up by the power of gravity. This was a very economical method, but it could be used only on a comparatively small part of the entire length of the road. What was sought was some means of working the coal trains by a "travelling engine" instead of by horses.
Stephenson now applied himself to the study of the locomotives that were already constructed. At Wylam he inspected "Black Billy," and at the collieries of Kenton and Coxlodge he saw one of Blenkinsop's Leeds engines draw sixteen coal wagons with an aggregate weight of seventy tons at the rate of about three miles an hour. Yet this engine proved unsteady and costly to work. An effective and economical locomotive engine still was to be invented, and to this object Stephenson devoted his attention.
Lord Ravensworth, the principal partner in the Killingworth colliery, having a very favorable opinion of Stephenson's ability owing to the important improvements he had already made, authorized him to construct a locomotive, or what Stephenson called a "travelling engine." The inventor had difficulty in obtaining competent mechanics and satisfactory tools with which to work, but he built a locomotive and it was successfully tried out on the Killingworth Railway in July, 1814. In many ways this locomotive was patterned after Blenkinsop's engine, but the wheels were smooth, for Stephenson was convinced that the adhesion between a smooth wheel and an edge-rail would be as efficient as Blackett had proved it to be between a wheel- and a tram-road. This "travelling engine," which was popularly called "Blucher," was the most successful locomotive that had yet been built, but it was nevertheless a cumber-some and clumsy machine ; the parts were huddled together, its progress was a succession of jolts which deranged the machinery, it had no springs, and when the teeth of the cogwheel became worn the engine rattled as it moved.
The principal test of the success of the locomotive was its economy as compared with horse power, and it was found that at first the working of the engine was barely economical and at the end of the first year's trial the steam power and the horse power were practically upon a par in point of cost. It could not travel at a speed beyond a horse's walk nor accomplish on an average more than about three miles an hour. Locomotives might have been abandoned at this juncture had not Stephenson hit upon the steam blast, which at once more than doubled the engine's power.
Stephenson was a remarkably accurate and careful observer and his success was mainly due to the patient study he gave to facts he observed and his application of them to useful account. In his first locomotive the eduction steam was allowed to escape into the atmosphere with a hissing blast, which frightened horses and cattle, and caused a neighboring land-owner to threaten suit against the colliery for maintaining a nuisance. The inventor had already noticed the much greater velocity with which the steam issued from the exit pipe than that with which the smoke escaped from the engine's chimney. He thought that, by conveying the eduction steam into the chimney by a small pipe after it had done its work in the cylinders and by allowing it to escape in a vertical direction, its velocity would be imparted to the smoke from the fire, or to the ascending current of air in the chimney, thereby increasing the draught and the intensity of combustion in the furnace.
This theory proved correct ; when he tried it out in practice he found that combustion was stimulated by the blast, the capability of the boiler to generate steam was greatly increased, and the engine's effective power was augmented in the same proportion, without adding to its weight. This discovery of the steam blast was all important in the history of rail-ways; without it locomotives would have been scarcely more effective than horse power.
The inventor now built a second locomotive and took out a patent in 1815 for an engine which combined the essential requisites of economical use, few parts, simplicity in construction, and directness in the method by which the power was communicated to the wheels. To obtain that degree of flexibility combined with direct action. which was needed to insure power and avoid friction and jar from irregularities in the road Stephenson made use of the "ball and socket" joint for effecting a union between the ends of the cross heads where they united with the connecting rods, and between the ends of the connecting rods where they were united with the crank-pins attached to each driving wheel. In this way the parallelism between the cross head and the axle was at all times maintained.
In this second locomotive, built in 1815, Stephenson had constructed an engine which had these important improvements on all those previously devised : simple and direct communication between the cylinder and the wheels on the rails, joint adhesion of all the wheels, attained by the use of horizontal connecting rods, and a method of increasing the combustion of the fuel by employing the waste steam, which had formerly been allowed to escape into the air.
While busily occupied with his locomotive, Stephenson yet found the opportunity to invent a safety lamp, known as the "Georgy Lamp," which furnished a great protection against explosions of fire-damp in the coal mines. Meantime his "travel-ling engine" was regularly employed drawing coal wagons and he was studying how to make it more efficient and economical. He took up the subject of the rails, which at that time were laid in a loose manner and seldom repaired, with the result that there was a great loss of power in the engine and much wear and tear of the machinery from jolts of the wheels against the rails. To remedy this he devised a new chair with a new method of fixing the rails therein; instead of the butt joint which had been used in all cast-iron rails he adopted the half-lap joint, by which the rails extended over each other at the ends, and these ends, instead of resting upon a flat chair, were constructed to rest upon the apex of a curve forming the bottom of the chair. This invention, and that of what he called his Steam Springs—designed to distribute the weight of the engine equally on all the four wheels—greatly increased the smoothness of travel and its economy.
Yet, although the Killingworth railway was in regular use, the possibilities of the locomotive for passenger and goods traffic were slow to be appreciated in England. There were only a few men who glimpsed them as did Mr. Edgeworth, who wrote to James Watt in 1813: "I have always thought that steam would become the universal lord, and that we should in time scorn post-horses. An iron railroad would be a cheaper thing than a road on the common construction." Some did, however, become interested, and two of the most prominent were William James of West Bromwich and Edward Pease of Darling-ton.
James, a man of considerable fortune, and financially connected with the coal trade, had seen Trevethick's engine at Merthyr Tydvil, and afterwards, with Lord Redesdale, constructed a railway to be worked by locomotive power between Stratford-on-Avon and Moreton-in-the-Marsh. He projected rail-roads in various parts of England, but found people in authority constantly opposing his schemes. Ed-ward Pease, of Darlington, like James, was connected with coal mines, and desired to improve the traffic conditions of his neighborhood, so as to obtain new markets for the large stores of coal in the Bishop Auckland valley above Darlington. With this object he planned in 1817 to build a railway from Witten Colliery, a few miles above Darlington, to Stockton.
This project met with much opposition. When Pease tried to organize a company for the purpose of surveying and constructing his road the people of the district ridiculed the notion and predicted it would ruin everyone connected with it; even those who were most interested in acquiring new markets, the merchants and ship-owners, would not contribute money. Pease persevered, and succeeded in inducing his friends and relations, many of whom, like him-self, were members of the Society of Friends, to sub-scribe for shares. "The Quakers' Line" the road was called on account of its sponsors. When permission of Parliament was sought to build the railway it was refused owing largely to the opposition of the Duke of Cleveland, who objected on the score that the road as proposed passed near one of his fox covers.
A new survey was made, avoiding the duke's pre-serves, and ultimately, in 1821, Parliament passed the Stockton and Darlington Railway Act.
Meantime the owners of the Hetton Colliery, in the county of Durham, had decided to convert their wagon-way into a locomotive railroad. Knowing of George Stephenson's success with engines at Killing-worth, these Durham coal-magnates invited him to become the engineer of their new line, and Stephen-son's employers, pleased at the compliment paid their colliery engineer, permitted him to accept the offer. The project was important. The railway ex-tended from the Hetton Colliery to the shipping-place on the banks of the Wear, near Sunderland. Its length was about eight miles and its route crossed Warden Low, one of the highest hills in the district. The character of the country prevented the building of a flat line, or one of easy gradients, except by the spending of much more money than the owners would allow Stephenson. What he had to do was to construct his road to conform to the country it traversed and to adapt the mechanical methods employed for the working of the railway to the character of the gradients, which in some places were heavy.
His achievement was eminently successful. On the Hetton line when completed there were five self-acting inclines, where the full wagons drew the empty ones up, and two inclines that were worked by fixed reciprocating engines of sixty horse-power each. The locomotive "travelling engine" supplied all the other power. The Hetton Railway was opened on November 18, 1822, before crowds of curious spectators, who saw five of Stephenson's locomotives at work under the direction of his brother Robert and shipments of coal being made to the terminals on the Wear. The locomotives travelled at about four miles an hour, and each engine drew a train of seventeen wagons, weighing about sixty-four tons.
In constructing the Hetton Railway George Stephenson. had demonstrated his ability not only as a builder of locomotives but as a railroad engineer.