The evolution of the steam locomotive (1803 to 1898)

To Richard Trevithick, the Cornish mine captain and engineer, belongs the honour of producing the first locomotive—true, his original essay was a road locomotive. As long ago as 1796 he constructed a model locomotive which ran round a room; and on Christmas Eve, 1801, he made the initial trip with his first steam locomotive through the streets of Camborne. This machine carried several passengers at a speed in excess of the usual walking pace of a man. Trevithick was joined in the enterprise by his cousin Vivian, who provided the money to build the steam engines, and to patent them, their first patent being dated 24th March, 1802. It is described as “for improving the construction of steam engines, and the application thereof for drawing carriages on rails and turnpike roads and other purposes.” It was claimed that their engine would produce “a more equable rotary motion on the several parts of the revolution of any axis which is moved by the steam engine, by causing the piston-rods of two cylinders to work on the said axis by means of cranks, at a quarter turn asunder.”

Among other improvements claimed in the specification, mention should be made of the return tube boiler, bellows to urge the fire, and a second safety valve, not under the control of the driver.

A steam carriage with these improvements was constructed, and Vivian and Trevithick commenced a journey on it from Camborne to Plymouth, from which port it was shipped to London. On the road to Plymouth a closed toll-bar was met, and the steam carriage stopped for the gate to be opened. “What have us got to pay here?” demanded Vivian. The affrighted toll-keeper, shaking in every limb, and his teeth chattering, essayed to answer, and at last said, “Na—na—na—na.” “What have us got to pay, I say?” demanded Vivian. “Na—noth—nothing to pay, my de—dear Mr. Devil; do drive on as fast as you can. Nothing to pay.”

It must be remembered that to Cornishmen of a century ago the devil was a very real personage; and, seeing the horseless carriage proceeding with a fiery accompaniment, the poor toll-keeper thought he had at last seen his Satanic majesty. He also appears to have remembered that it is well “to be civil to everyone, the devil included; there is no knowing when you may require his good wishes.” Hence the toll-keeper’s reason for calling Vivian “my dear Mr. Devil.”

As early as August, 1802, R. Trevithick (according to his life, as written by his son, F. Trevithick) appears to have constructed a railway locomotive at Coalbrookdale. This engine had a boiler of cast-iron 1½in. thick, with an interior return wrought-iron tube. The length of the boiler was 6ft., and the diameter 4ft. The cylinder working this engine was 7in. in diameter, the stroke being 3ft. The next railway locomotive was that constructed for the Pen-y-darren Tramroad near Myrthyr Tydvil. Of this particular locomotive (Fig. 1) it is possible to obtain authentic particulars, although much that is legendary already clusters around this historic locomotive. For instance, we read that the locomotive in question had a brick chimney, and that it was demolished by colliding with an overhanging branch of a tree. Then the amount of the bet between Mr. Homfray, the owner of the tramroad, and his friend, as to whether the locomotive would successfully perform a journey from Pen-y-darren to the navigation at Plymouth, is a variable quantity. The amount staked has been stated to be £500 a side, and also £1,000 a side.

It is evident that some days prior to February 10th, 1804, the engine successfully performed the journey, and that overhanging trees and rocks considerably impeded the travelling, several stoppages having to be made whilst these obstacles were removed. Mr. Homfray, however, won the bet. On February 21st another trip was made by the locomotive. On this occasion the load consisted of 5 wagons, 10 tons of bar iron, and 70 passengers, the weight of the engine, with water and fuel, being 5 tons; the journey of nine miles being performed in 4 hours 5 minutes, including several stoppages; the average speed when travelling being five miles an hour. On the return journey the engine hauled the empty wagons up an incline of 1 in 18 at the rate of five miles an hour. Several of the tram-plates, which weighed only 28lb. per yard, were broken on the downward trip. Early in March the engine conveyed a load of 25 tons from the iron works to the navigation.

It will be observed that this engine from the first decided the practicability of conveying loads by means of smooth wheels on smooth rails, simply by adhesion. Yet, strange to say, for several years after, it was the firmly-fixed belief of succeeding locomotive constructors that it was impossible to obtain sufficient adhesion between a smooth surface and a smooth rail to successfully work a locomotive. The result was the invention of many curious methods to overcome this apparent difficulty, which, as a fact, never existed, save in the minds of the designers of the early locomotives. These men do not seem to have been fully acquainted with the results of Trevithick’s experiments on the Pen-y-darren tramroad in 1804.

A description of this locomotive prototype is of interest. The boiler was cylindrical, with a flat end. The fire-door and chimney were both at the same end, an extended heating surface being obtained by means of the return tube; above the fire-door was the single horizontal cylinder, the diameter of which was 8¼in.; a considerable portion of the cylinder was immersed in the boiler, the exposed portion being surrounded by a steam jacket. The stroke was 4ft. 6in.! The piston-rod worked on a motion frame extending in front of the engine. At the other end of the boiler was a fly-wheel some 9ft. 6in. in diameter, the motion being conveyed to it by connecting-rods from the cross-head; a cog-wheel on the fly-wheel axle conveyed the motion by means of an intermediate wheel to the four driving wheels, which are stated to have been 4ft. 6in. in diameter. The exhaust steam appears to have been turned into the chimney, not for the purpose of a blast, but only as an easy method of getting rid of the vapour. It will be remembered that Trevithick, in his patent specification, specially mentioned bellows for urging the fire, and was, therefore, not acquainted with the nature of the exhaust steam blast. It is important to bear this in mind, as the reader will find in a later chapter. This engine is stated to have blown up through not being provided with a safety valve, though Trevithick specially ordered one to be fixed to the boiler, but his instructions do not appear to have been carried out.

Trevithick made another locomotive, called “Catch-me-who-can.” This ran on an ellipse-shaped railway specially laid down for it at Euston Square, London, and was visited by many people during the few days it was on view. Another locomotive was constructed from the drawings of Trevithick’s Coalbrookdale locomotive of 1802, to the orders of Mr. Blackett, the owner of Wylam Collieries. This engine weighing 4½ tons, had a single cylinder 7in. diameter, 3ft. stroke, and, of course, a fly-wheel. For some reason or another this engine does not appear to have been used on the Wylam tramroad, but was used in a Newcastle foundry to blow a cupola. Mr. Armstrong, a former Locomotive Superintendent of the Great Western Railway, was acquainted with this engine of Trevithick’s at the time it was so employed at Newcastle.

Having given an outline of Trevithick’s invention of the tramroad locomotive, and the other locomotive engines designed by him, we will deal with the locomotive built for J. Blenkinsopp (Fig. 2), of the Middleton Colliery, near Leeds, who, on April 10th, 1811, obtained a patent for a self-propelling steam engine, worked by means of a cog-wheel, engaging in a rack laid side by side with one of the rails forming the tramway.

The erroneous idea that the locomotive of itself had not sufficient adhesion between the smooth wheel and the surface of the rail to propel itself and draw a load was strongly entertained by Blenkinsopp, hence his patent rack and pinion system. Blenkinsopp having this opinion, which he published by means of his patent specification, caused succeeding inventors to fall into the same error regarding the adhesive properties of the locomotive, and consequently considerably retarded the development of the railway engine.

Although this engine is generally known as Blenkinsopp’s, it was constructed by Matthew Murray, the Leeds engineer. The boiler was cylindrical, with slightly convex ends, a single flue ran through it, which was in front turned upwards, and so formed the chimney; the fire-grate was at the other end of the flue, as in the modern locomotive.

This engine was provided with two cylinders, and was, in this respect, an improvement on Trevithick’s single cylinder engines. The cylinders were 8in. in diameter, and placed vertically, the major portion of them being placed within the boiler. The stroke was 20in., and the motion was conveyed by means of cross-heads, working connecting-rods; these came down to two cranks on either side below the boiler. The cranks worked two shafts fixed across the frames, on which were toothed wheels, both working into a centre toothed wheel, which was provided with large teeth, these engaged on the rack rail previously described. The cranks were set at right angles, so that one piston was exerting power when the other was at its dead centre, and vice versâ. The engine was supported on the rails by four wheels 3ft. 6in. in diameter. The two cylinders were connected by a pipe which conveyed the exhaust steam and discharged it into the atmosphere through a vertical tube. The engine weighed 5 tons, burned 75lb. of coal per hour, and evaporated 50 gallons of water in the same time. This locomotive could haul 94 tons on the level at 3½ miles an hour, or 15 tons up an incline of 1 in 15; its maximum speed was 10 miles an hour. The engine cost £400 to construct, and worked from August, 1812, for a period of about 20 years, and in 1816 the Grand Duke Nicholas, afterwards Emperor of Russia, inspected the machine. The tramway on which it worked was about 3¾ miles long.

In September, 1813, Murray supplied two of Blenkinsopp’s engines to the Kenton Colliery.

On December 30th, 1812, a patent was granted to William and Edward Chapman for a method of locomotion. A chain was stretched along the railway and fastened at each end; connected to the locomotive by spur gear was a barrel, around which the chain was passed. When the barrel rotated, the chain was wound over it, and since the chain was secured at either end, the engine was of necessity propelled. An engine on this principle was tried on the Heaton Colliery Tramroad, near Newcastle-on-Tyne. The machine was supported on wheels travelling on the rails. The boiler was of Trevithick’s design, and fanners were used to excite the combustion of the fuel. The weight of Chapman’s engine was 6 tons. After a few trials the scheme was abandoned, as it was found impracticable to successfully work such a system. Every eight or ten yards the chain was secured by means of vertical forks, which hold it when disengaged from the drum of the locomotive.

By this method the pressure of one engine on the chain was limited to the fork on either side of the drum instead of being spread over the whole length of the chain, and it would, therefore, have been possible for several engines to have used the chain at one and the same time.

According to Luke Herbert and Lieut. Lecount, Chapman also built an 8-wheel locomotive for the Lambton Colliery. This engine, it was stated, had vertical cylinders, and the motion was conveyed by means of spur wheels. It weighed 6 tons loaded, and drew 18 loaded wagons, of a gross weight of 54 tons, from the colliery to the shipping place on the Wear; with the above load it attained a speed of four miles an hour up an incline of 1 in 115. The dimensions and capabilities accredited to this engine appear suspiciously similar to those related of the first Wylam locomotive.

On May 22nd, 1813, Mr. W. Brunton, of the Butterfly Ironworks, obtained a patent for a novel method of steam locomotion. This locomotive inventor was also suffering from the common belief that it was impossible to obtain sufficient adhesion between a smooth rail and smooth wheels, despite the successes that had already been obtained in this direction by Trevithick. He therefore built an engine supported on four flanged carrying wheels, but propelled from behind by means of two legs. Indeed, another inventor considered the idea of steam legs so natural that he constructed a steam road-coach that was to be propelled by four legs, one pair partaking of the character and motion of the forelegs of a horse, and the other pair being fashioned on the model of the hind legs of the same quadruped.

In Brunton’s leg-propelled steam locomotive (Fig. 3) we find that the boiler was cylindrical, with a single horizontal tube passing through it, and turned up in front in a vertical position, thus forming the chimney. The motion was obtained from a single horizontal cylinder, fixed near the top of the boiler, the piston-rod projecting behind; the end of the piston-rod was attached to a jointed rod, the bottom portion of which formed one of the legs. The upper portion of this rod was attached to a framework fixed above the boiler of the engine, which formed a fulcrum, and then by an ingenious arrangement of levers, an alternate motion was given to the second leg. Each leg had a foot formed of two prongs at the bottom; these stuck in the ground, and prevented the legs from slipping. Upon steam being applied, the piston in the ordinary way would have travelled to the end of the cylinder, but the leg, having a firm hold of the ground, presented a greater resistance to the steam than did the weight of the engine, so the steam acting on the surface that presented the lesser resistance, caused the cylinder to recede, and with it the engine, to which it was, of course, firmly attached. By means of the reciprocating levers, a horizontal rod travelled on the top of the boiler and over a cog-wheel; then on the other side of this cog-wheel was another horizontal rod, which, actuated by the cog-wheel, travelled in a contrary direction, and being attached to the other leg of the engine, as the machine receded from the first leg, it drew the second leg close up to the back of the engine. The second leg was now ready to propel the engine, which it did upon the steam being applied to the other side of the piston, and the process was alternated with each admission of steam to the front or back of the piston.

Whilst the legs were returning towards the engine the feet were raised by means of straps or ropes fastened to the legs and passing over friction-wheels, movable in one direction only by a ratchet and catch, and worked by the motion of the engine.

Brunton called his locomotive a “mechanical traveller,” and stated that the boiler was of wrought-iron, 5ft. 6in. long and 3ft. diameter, weighing 2¼ tons, stroke of piston, 2ft., and at 2½ miles per hour, with a steam pressure of 451b. per square inch, was equal in power to nearly six horses. This locomotive curiosity blew up at Newbottle in 1816, and about a dozen people were thereby either killed or seriously injured.