{65}

RAILWAYS.

By JOHN TATAM STANESBY.

A Railway is a road in which smooth tracks of wood, iron, or other suitable material are laid to facilitate the motion of wheel-carriages. Railways are of various kinds, and have long been used as a means of transport for minerals and heavy goods; and recently, in conjunction with locomotive steam-engines, they have been introduced very extensively for the purposes of general conveyance.

History.—It does not appear that any satisfactory notice of what may fairly be considered a railway is to be found before the seventeenth century, in the early half of which wooden rail, tram, or waggon ways were introduced in the collieries of the north of England. They were adopted in order to reduce the labour of drawing coals from the pits to the places of shipment in the neighbourhood of Newcastle-upon-Tyne, and they consisted simply of pieces of wood imbedded in the ordinary road, in such a manner as to form wheel-tracks for the carts or waggons. The wooden tracks presented a much smoother surface for the wheels than the very imperfect roads previously used, and therefore greatly increased the available power of the horses. The advantages even of this rude kind of railway were so great as to cause its extensive introduction in various mining districts, and in course of time several improvements were made upon it. About 1765, from a hundred to a hundred and fifty years after their first introduction, the wooden railways appear to have been made in the following manner:—The road was prepared by being levelled, or reduced to as uniform an inclination as circumstances would allow; pieces of wood, roughly squared, about six feet long and four to eight inches square, were then laid across it at a distance of two or three feet from each other, and upon these other pieces, carefully sawn, about six or seven inches wide and five deep, were fastened by means of pegs, in such a manner as to form two wheel-tracks, about four feet apart. The road was then completed by filling the spaces between the crosspieces (which are called sleepers), and also the spaces under the rails, with ashes, gravel, or other road materials. Fig. 1 is an elevation and ground-plan of this primitive railway, a a being the sleepers, and b b the rails.

An important improvement on this construction consisted in the addition of a second set of rails, similar to the first, and spiked or pegged down to them, as shown in the elevation, fig. 2, in which c represents the upper rail. By this improvement several inconveniences were removed, as the upper rails might be repeatedly renewed without disturbing the substructure. Another advantage of the change was that, by the rail being raised, a greater depth of ballast or road material might be spread over the sleepers, to protect them from the horses’ feet.

The vehicles used upon these wooden railways were generally waggons, carrying from two to three tons of coal, and mounted upon small wheels. The wheels were sometimes provided with a flange, or projecting rim, which, by coming in contact with the side of the rail, kept the waggon in the proper direction. Each waggon was drawn by one horse.

It became usual, at least as early as 1716, to nail thin plates of malleable iron upon the surface of the wooden rails, wherever a steep ascent or a sharp curve rendered the draught harder than usual. The circumstances in which these lines were used were such that there was almost invariably a descent towards the river or sea-shore, which, being in favour of the load conveyed, was an advantage. Where the descent would otherwise be too abrupt, it was not unusual to make an elevated staith at the river end of the railway, and shoot the coal from the waggons, by an inclined plane, into the hold of the ships. Sometimes also, where the inclination would prove inconvenient if distributed equally along the line, it was so arranged that the greater part of the railway was made of a convenient descent, and the remaining fall accomplished by one or more inclined planes, or runs, which the waggons were allowed to descend by their own gravity, the velocity being checked by a piece of wood, called a brake or convoy, which was pressed forcibly upon one or both wheels on one side of the waggon.

The wooden railway continued in use for a century and a half without any important step being taken for the introduction of a more durable material. Some stone-ways were constructed for similar purposes, but, though possessing many advantages, they are not so smooth as those of wood. The next material improvement was the use of cast-iron plates upon the wooden rails. It is somewhat remarkable that, notwithstanding the well-known effect of iron plates in diminishing the resistance, and their frequent use as already stated, this experiment is said to have been made more in consequence of accidental circumstances than as a premeditated measure of improvement. A wooden railway was in use at the Colebrook Dale ironworks, about the year 1767, when the price of iron became very low, and it was determined, in order to keep the furnaces at work, to cast bars which might be laid down upon the wooden rails, and which it was proposed to take up and sell as pigs in case of a sudden rise. This plan was suggested by Mr. Reynolds, who erected the first iron bridge set up in England, also at Colebrook Dale. These bars, or “scantlings of iron,” as they were called, were five feet long, four inches broad, and an inch and a quarter thick, and were cast with three holes for convenience of nailing to the wooden rails. Mr. Hornblower, an ingenious mechanician, in describing this road, remarks on the facility with which vehicles might be turned off the track when required, owing to the absence of a guiding flange; but this is a convenience incompatible with some of the most important qualities of a railway. Various plans have been proposed for combining the smoothness of a railway with the character of a common road, and of these perhaps none is more feasible than that patented by Mr. Woodhouse, in 1803, in which, by ingenious arrangements, rails of the sectional form represented by fig. 3 are imbedded in an ordinary pavement or road. The concave form of the upper surface of the rail would tend to keep carriages in the right direction, and yet admit of their being turned out without difficulty. The ease of draught which would be attained by such a plan may be conceived by observing the effect of the iron gutters in some of the streets of London, which closely resemble {66} Woodhouse’s rail in form, and are frequently made use of as wheel-tracks by drivers, notwithstanding the inconvenience arising from their being confined to one side of the vehicle.

Shortly after the experiment at Colebrook Dale, cast-iron rails with an upright flange, as shown in section in fig. 4, were brought into use. They were first used, it is believed, at the colliery of the Duke of Norfolk, near Sheffield, in 1776. Originally they were fixed upon cross sleepers of wood, like those used to support wooden rails. They were cast with holes for nails, and laid down so that both the flanges were towards the middle of the track, or vice versâ. Thus, as explained by fig. 5, which represents an end section of the two rails fixed to a sleeper, with a pair of wheels on them, one flange on each rail is sufficient to prevent carriages from running off.

About the year 1793 blocks of stone were introduced as supports, instead of the wooden sleepers. They were, in the early railways, about a foot square, and eight or nine inches deep. One of these blocks is imbedded in the road under each joint in the rails, which are spiked down to wooden plugs inserted in the stone. As the foundation made by stone blocks is firmer than that of wooden sleepers, they were quickly introduced in most cases where a durable road was required.

Many ingenious improvements have been made upon the kind of railway just described, which is still extensively used in mining districts. It is, for distinction, called the plate-railway or tramroad, and is very convenient from the facility of its construction, and the circumstance that vehicles adapted for use upon it can also be used off the rails. The form of the rail is however a weak one, considering the quantity of iron used; and it permits the lodgment of stones and dirt. The former of these inconveniences has been in some degree remedied by the use of a rail with an under rib, as shown in fig. 6, a form which was adopted to reduce the cost of repairs on the Surrey tramroad.

The serious disadvantages of the plate-railway led to the use of edge-rails, which have now almost entirely superseded the previous form. The first edge-railway of any considerable extent was completed in 1801, for the conveyance of slate from the quarries of Lord Penrhyn. Its construction is illustrated by fig. 7, which represents the two rails, and the form given to the tire of the wheels in order to keep them in the right course. These rails were of an oval section, the longest diameter being vertical. They were four feet six inches long, and had a dovetailed block cast beneath each end, which fitted into an iron sill imbedded in the road. The wheels were formed with a grooved tire, fitting loosely on the rail. It was found however that in course of time the groove became so deepened by wear as to fit the rail tightly, and thereby produce much friction. To remedy this, Mr. Wyatt, the inventor, introduced a rail and wheel formed as shown at b, fig. 7, in which the bearing surface of the rail and the corresponding part of the wheel were flat. The rails being laid only two feet apart, the carriages were necessarily small, and the friction considerable; yet the saving of power effected was such that two horses regularly drew a train of twenty-four waggons, each containing about a ton.

Edge-rails were adopted extensively by the coal-owners of Northumberland and Durham, within a few years after the successful experiment at Penrhyn. The form of rail most generally adopted was even better calculated to economise the strength of the iron than that of Mr. Wyatt. The following figures represent a mode of construction introduced early in the present century, and which is still used for colliery railways. The rails are cast in lengths of three or four feet, and their greatest sectional dimension is in the depth. They are made of what is called a fish-bellied form, the lower edge being curved so as to give the rail greater depth in the centre than at the ends or points of support. a, fig. 8, represents the cross section of the rail in the middle, and b at the end. The ends are so made as to form a half-lap joint (fig. 9), and they fit into a suitable cavity in a cast-iron pedestal or chair, which is spiked down to the ordinary stone blocks or wooden sleepers. A side view of the rail with two chairs is given at c, fig. 8, and the upper part of the figure is a section of the railway as completed, showing also the form of wheel employed. In this plan the protecting flange is upon the wheel instead of the rail. By this arrangement the flange may be made much smaller than that of a tram-plate, and the friction is usually still further diminished by giving a slightly conical form to the wheel-tires, so that the flanges are rarely brought into actual contact with the rails.

Although the principle of construction here given is that most commonly followed, the details vary so much that hardly any two railways are alike. The sectional forms of edge-rails, though very various, generally resemble that here represented; and the fish-bellied profile has been selected as having been formerly the most usual; although parallel rails, or those of equal depth throughout, were also much used in the earlier railways. The form of the chairs or pedestals, and the method of securing the rails to them, are also very variable. In figs. 8 and 9 the rails are represented as having half-lap joints, the two ends being placed together between the cheeks of the chair, and fastened by a pin driven through the whole. Sometimes the ends of the rails are made square, abutting against one another in the chair, and secured by a separate pin through each rail. Since the general introduction of locomotive engines, the use of pins has been abandoned, as they have a tendency to work loose; and wedges or keys, which may be tightened when necessary, have been applied in different ways in their stead. In some cases edge-rails have {67} been cast with a pedestal attached to one end, fitted to receive the opposite end of the adjoining rail.

The introduction of malleable iron as a material for rails is an improvement which may perhaps be considered to have done more than any other in preparing railroads for becoming the principal highways of a commercial country. From the commencement of the use of iron railways much inconvenience was caused by the frequent breakage of the rails, especially those of the tram-plate form. The brittleness of cast-iron rendered it necessary that the rails should be made much stronger than sufficient to bear ordinary loads, that they might be able to resist accidental strains and shocks; but although many of the earlier railways were relaid with heavier rails than were originally supposed needful, breakages were of very common occurrence. So long as the travelling was restricted to a low rate of speed, the accidents and delays thus occasioned were of minor importance, but the difficulty of guarding against them would no doubt have greatly retarded the use of railways for the conveyance of passengers, if an adequate remedy had not been provided before the experiment was made. Bars of malleable iron were laid down as rails to a limited extent in or before 1808, and some engineers advocated their use, notwithstanding the inconvenience arising from their unsuitable form; no machinery being then used by which they could be made economically in any other than a square or flat form. The desire to introduce a more durable rail led also to experiments on the combination of wrought and cast iron; but these and all similar contrivances were superseded in 1820 by Mr. Birkenshaw’s invention of an efficient and cheap method of rolling iron bars suitable for rails and other purposes. The fibrous texture of wrought-iron makes it far less likely to break when subjected to concussion than cast-iron, and the sectional form used is such as to render bending improbable. Malleable rails, when in use, do not rust to any material extent, while the same rails, if lying on the ground beside the track, rapidly waste away. It is also an important advantage of malleable rails that they effect a reduction in the number of joints: they are usually made fifteen feet long, while the brittleness of cast rails rendered it unsafe to have them more than three or four feet, the space between two points of support. Originally the long wrought rails were confined to the parallel form, but they are now, by a very ingenious adaptation of rolling-machinery, made fish-bellied when that form is preferred.

The application of railways was till recently limited to the conveyance of minerals and merchandise, and that at a very moderate velocity. The carriages were usually four-wheeled waggons, of small dimensions compared with those used on ordinary roads, in order that the weight might be distributed over a considerable length of road. Being guided in the required direction by the flanges, it is unnecessary to attach the axles of railway carriages in such a manner as to enable them to turn, and the wheels to lock under the body, as in common vehicles; and for the same reason, combined with the greater straightness of a railway, it is unnecessary to allow the wheels to revolve independently of the axles. The most approved plan, especially for edge-railways, is to fix the wheels firmly to the axle, and allow the axle to revolve in bearings attached to the body of the carriage. The wheels are almost invariably made of iron, those for slow traffic being cast, and others either wholly or partially made of malleable iron, in order to diminish the risk of fracture. Cast-iron wheels were found to wear very rapidly when used upon wrought edge-rails, but the application of the case-hardening process has rendered them more durable. From a very early period railway vehicles have been fitted with an apparatus called a brake, consisting of a piece of wood adapted to the form of the wheel-tires, and capable of being pressed against them by levers or screws with sufficient force to impede or arrest their revolution. Previous to the recent adaptation of railroads to rapid travelling, the use of springs was not common either in carriages or locomotive engines.

Animal power was the only means of locomotion originally employed on railways to any considerable extent; but the purpose to which they were applied, that of conveying mineral produce to a place of shipment, led to the application of gravity as an auxiliary, and, in some cases, as the sole source of motion. In such a case, where the inclination of the ground is very moderate, the slope of the road is frequently so adjusted that no greater power is required to take a loaded carriage down, than to take it up again when empty. When a declivity occurs steeper than is convenient for the ordinary power, an ingenious arrangement, called a self-acting inclined plane, is occasionally resorted to; on which a loaded carriage, or train of carriages, is allowed to run down by the force of gravity, drawing a rope, which, after passing round a wheel at the top of the incline, is conducted down the slope and attached to an empty train—the force of the descent of the loaded vehicles being sufficient to cause the empty train to run up to the top of the plane. This admirable contrivance was introduced in the latter part of the last century, and is still extensively used. Stationary steam-engines, which draw the carriages by means of ropes guided by pulleys or sheaves in the centre of the track, have been used from an early period, generally in situations where the ascent is too great to be conveniently mounted by horse-power. Locomotive or moveable steam-engines, in many different forms, have also been tried at various times since about the year 1805, although for more than twenty years after that time their powers were very imperfectly developed.

In the following notice of the steps by which the locomotive engine has been brought to its present state of comparative perfection, those points only will be dwelt upon which are peculiar to that machine as applied to railroads.

The possibility of applying the steam-engine to the purposes of locomotion was conceived by several of its earliest improvers, and in 1784 a plan was suggested in one of the patents of Watt; but it does not appear that either he or any other inventor carried their ideas into practice until about 1802, when Messrs. Trevithick and Vivian patented a high-pressure engine which was admirably adapted for locomotive purposes. Within a few years they built several carriages, one of which, at least, was for use on a common road. In 1805 they made experiments with a machine similar to that represented by the annexed cuts, on a tramway near Merthyr Tydvil, and thereby proved the practicability of their plan. Notwithstanding the extreme simplicity of this machine, it possessed almost all the essential arrangements of the modern engines.

Fig. 10 is a side and end elevation of this machine, the same letters in each referring to the same parts: a is the boiler, which is of a cylindrical form, with flat ends. The fire is contained in a large tube within, and on one side of, the boiler. One end of this is seen at b, and the form is indicated by dotted lines in the side view. This tube extends nearly to the opposite end of the boiler, and then, being diminished in size, it is turned round and brought out to the chimney at c. The fire-tube is completely surrounded by the water, by which arrangement steam is generated with great rapidity and of a high degree of elasticity. The steam cylinder is {68} placed vertically at d, being immersed nearly to the bottom of the boiler, as shown by the dotted lines. The steam is admitted alternately above and below the piston by means of a fourway-cock in a valve-box at the top of the cylinder; and the waste steam, after propelling the piston, passes by the eduction pipe e into the chimney, where its emission causes a strong draft. The upper end of the piston-rod is attached to a crosshead f, which slides up and down on vertical guides, and from the ends of which connecting rods g g descend to cranks fixed on the axles of the fore-wheels, which are thus caused to revolve like the fly-wheel of a stationary engine: h is a safety-valve on the upper part of the boiler. The immersion of the working cylinder in the boiler is happily contrived for compactness and economy of heat, and has been frequently imitated in subsequent engines; and the admirable arrangement of throwing the waste steam into the chimney has been almost invariably followed, as it affords a blast always proportionate to the speed of the engine, and the consequent demand for the evolution of steam. This machine, when tried on the Merthyr tramway in 1805, drew a train of waggons containing ten tons of iron and a considerable number of persons, at the rate of five miles per hour. A supplementary carriage followed the engine to carry a supply of fuel and water; and a small force-pump, worked by the machine itself, maintained the requisite quantity of water in the boiler.

Trevithick was aware that, although the adhesion between the engine-wheels and the rails was sufficient to ensure the progressive motion of his machine on a level or nearly level road, the wheels would slip round without advancing if the inclination were considerable, or the load attached too great. He therefore in his patent proposed to remedy this by making the propelling wheels uneven by the projecting heads of bolts, cross-grooves, or fittings to railroads, where the adhesion of the plain wheels should prove insufficient. Being otherwise occupied himself, he did not proceed with his locomotive experiments. An erroneous idea was for many years generally entertained, that the adhesion of plain wheels was insufficient for any practical purpose, and consequently much ingenuity was expended in contrivances for securing progressive motion by other means. One of the most successful experimentalists in this way was Mr. Blenkinsop, who, in 1811, patented a locomotive engine in which the power was applied to a large cogged wheel, the teeth of which entered a rack laid down beside the ordinary rails. Blenkinsop’s engine was in other respects very similar to that of Trevithick, but two cylinders and pistons were employed, working separate cranks at an angle of 90°, so that one was exerting its full force while the other passed its dead points. Engines on Mr. Blenkinsop’s plan were worked for some years on a colliery line near Leeds, and drew very heavy loads at a slow rate; but the friction of the machinery was excessive, and they are consequently now disused. In 1812 Messrs. Chapman constructed engines on eight wheels, all of which were turned by the machinery in order to increase the adhesion. They also proposed to stretch a chain or rope along the railway, which should pass round a grooved wheel turned by the engine, and thereby aid the progressive motion.

In 1814 and 1815 engines were again tried with plain wheels, and, being found efficient, were used upon railways in the north of England. Several attempts have however been made since that time to introduce contrivances for increasing adhesion, to enable locomotive engines to ascend planes of greater inclination than they will do with smooth wheels alone.

Patents were taken out in 1816 and 1817, by George Stephenson, in connection with Messrs. Dodd and Losh, under which several locomotives were constructed and brought into operation upon colliery railways near Newcastle-upon-Tyne. The boiler in these machines resembled that of Trevithick, but the fire-tube passed completely through, instead of being turned and brought out at the back. Two vertical cylinders were used, each working a distinct axle and pair of wheels, the cranks of which were kept at the requisite angle of 90° by means of an endless chain stretched over grooved or toothed pulleys fixed on the axles; or, in the more recent engines, by connecting rods outside the wheels. Engines of this kind seldom exceeded a speed of about five miles per hour, unless unloaded, when they occasionally ran at the rate of ten or twelve.

When the projectors of the Liverpool and Manchester Railway were engaged in the design and execution of that great work in 1825 and the following years, the advantages of locomotive steam-engines were so imperfectly developed, that it was uncertain whether they should he adopted. The experiment of forming a railway for passengers as well as general merchandise traffic had scarcely been tried, although the Stockton and Darlington Railway, which was opened in 1825, had done more than any of its predecessors in showing the capabilities of a railway for such a use. As the Liverpool line approached completion, the directors were convinced that horse-power was ineligible, as it was intended to aim at considerable velocity. It was not so easy to decide on the comparative merits of stationary and locomotive engines. Various suggestions were made for the application of fixed engines at intervals of a mile or two along the line, to draw trains by ropes from station to station; but it was eventually determined to use locomotives, and to offer a premium of 500l. for the best which would fulfil certain conditions, of which some were that it should not emit smoke, should draw three times its own weight at the rate of ten miles per hour, should be supported on springs, not exceed six tons weight, or four tons and a half if on only four wheels, and should not cost more than 550l. The trial was fixed for October, 1829, when four steam locomotives were produced, one of which was withdrawn at the commencement of the experiment. Of the other three, the Novelty, by Messrs. Braithwaite and Ericson, was very light, and had the requisite draft produced by a blowing-machine. Its performance was very promising, until an accident with the boiler put an end to the experiment. More recent attempts have been made to introduce engines of similar construction, but they have not proved successful. The Sans Pareil, by Mr. Hackworth, was very similar to Trevithick’s engine, but had two cylinders, both working the same axle. The two pair of wheels were coupled together by connecting rods, so as to make use of the adhesion of them all. This engine attained a velocity of fifteen miles per hour with a gross load of nineteen tons, but at length gave way owing to a trifling accident. The remaining engine, the Rocket, was constructed by Robert Stephenson and Mr. Booth, of the Liverpool and Manchester Railway, and succeeded in performing more than was stipulated for.

The following cut represents a side view of the machine, {69} with a cross section of a portion of the furnace: a is a cylindrical boiler, with flat ends; b the fire-box, which is double, as indicated by the cross section, the fire being contained in the inner part, and the space of about three inches between the inner and outer casing being filled with water. Twenty-five copper tubes of three inches diameter extend longitudinally through the boiler, opening at one end into the fire-box, and at the other into the bottom of the chimney at c: d is one of the steam-cylinders, of which there were two, placed diagonally on the sides of the boiler. The piston-rods worked in guides, and by means of connecting rods transferred the motion of the pistons in a very simple and effective manner to the large wheels. It was arranged as usual that one piston was in the middle of its stroke while the other was at the end of the cylinder, and consequently powerless. The waste steam passed from the cylinders along the pipe e to the chimney, in order to produce draft: f f are pipes connecting the water in the casing of the fire-box with that in the boiler.

The use of several tubes of small diameter instead of one large flue through the boiler, is the most important peculiarity of this machine, as, owing to the great extent of surface of heated metal thus placed in contact with the water, steam was produced with extraordinary rapidity. This plan, which was suggested by Mr. Booth, has since been carried to a great extent, by reducing the diameter and increasing the number of the tubes. The inclined position of the steam cylinders caused the motion of the machinery to interfere less with the play of the springs than if they were placed vertically, but their situation had the disadvantage of exposing them to the cold air, by which the power of the steam is diminished—an inconvenience avoided in most subsequent engines by placing them horizontally in a casing under the chimney. The nuisance of smoke was prevented by the employment of coke as fuel. The Rocket, with a gross load of seventeen tons, averaged a speed of fourteen miles per hour; but under some circumstances it attained double that velocity. Subsequent engines built by Mr. Stephenson were of much greater power.

Great as are the advantages realised from this improvement in the means of intercourse, it is impossible, after the lapse of only ten years, to form an adequate idea of their importance; but the fact that it has led to an expenditure exceeding 60,000,000l. in the construction of railways in this kingdom alone indicates the magnitude of the changes introduced by it. Modern improvements will be treated of as they come under notice in a sketch of the operations of designing, constructing, and working a railway.