Engineers and Mechanics Encyclopedia 1839: Railways: George Stephenson and William Losh
In the subsequent year 1816, a patent was granted to George Stephenson, in conjunction with William Losh, of Newcastle, for "a method or methods of facilitating the conveyance of carriages and all manner of goods and materials along railways and tramways, by certain inventions and improvements in the construction of the machine, carriages, carriage-wheels, railways, and tramways employed for that purpose." The specifications of this patent is more ably written than such documents usually mere; and as it contains much valuable practical intelligence, we shall make some extracts from it, and accompany them by the necessary illustrations. The patentees commence their specification by explaining the distinction between edge-rails and the tram or plate-rails, as introductory to their improvements, which they thus explain.
"In the construction of our edge-railways, our objects are, first, to fix both the ends of the rails, or separate pieces of which the rails are formed, immovable, in or upon the chairs or props by which they are supported; secondly, to place them in such a manner that the end of any one rail shall not project above or fall below the correspondent end of that with which it is in contact, or with which it is joined; thirdly, to form the joinings of the rails with the pedestals or props which support them, in such a manner, that if these props should vary from their perpendicular position in the line of the way, (which in other railways is often the case,) the joinings of the rails with each other would remain as before such variation, and so that the rails shall bear upon the props as firmly as before.
"In the formation of our wheels, it is our object to construct them in such a manner, and to form them of such materials, as shall make them more durable and less expensive in the repairs than those hitherto in use. This invention was accomplish by forming our wheels either with spokes of malleable iron, and with cast-iron rims, or by making the wheels and spokes of cast-iron, with hoops, tires, or trods, of malleable iron; and in some instances, particularly for wheels of very small diameters, instead of spokes of malleable iron, we employ plates of malleable iron to form the junction between the naves and the cast- iron rims of the wheels.
Fig. 1 is a side view of the wheels, with wrought-iron arms. A-a-a show the arms cast in the nave, and dropped into mortice holes made in the rim, which are dovetailed, to suit the dovetailed ends of the arms a-a-a. The arms are heated red hot previous to dropping them into the holes, in order to cause them to extend sufficiently for that purpose, for when cold they are too short, owing to the property which iron possesses, of expanding on the application of beat, and of contracting again to its former dimensions on cooling down to the same temperature from which it .was raised; the arms, therefore, on cooling, are drawn with a force sufficient to produce a degree of combination between their dovetailed ends and the mortices of the rim, which prevents the possibility of their working loose; they are afterwards keyed sip; the mortice holes are also dovetailed, from the tail side of the wheel, (a-a, Fig. 2.) to the crease side (b in the same figure.)
Fig. 2 is a cross section through the centre of the wheel, with wrought-iron arms.
Fig. 3 is an end view of Fig. 2.
Fig. 4 represents an elevation of the edge railway, showing a rail a connected with the two adjoining rails, the ends of which are shown by b-b, and resting in the props or pedestals, the bases of which are the metal chairs that are bolted to the stone supports c-c. The joints e-e are made by the ends of the rails being applied to each other by what is termed a half lap; and the pin or bolt g which fixes them to each other, and to the chair in which they are inserted, is made to fit exactly a hole which is drilled through the chair and both ends of the rails, at such a height as to allow both ends of the rails to bear on the chair, and the bearance being the apex of a curve, they both bear at the same point. Thus the end of one rail cannot rise above that of the adjoining one; for although the chair may move on the pin in the direction of the line of the road, yet the rails will still rest upon the curved surface of their bearance without moving.
Fig. 5 is a cross section of our edge-railway through the middle of one of the chairs a, and across the ends of the two adjoining rails which are connected by a transverse pin; c is the stone support or sleeper.
Fig. 6 is a cross section of the rail a, at the centre, and shows the carriage c behind.
Fig. 7 is a plan of the railway described at Fig. 1, showing the half-lap joinings of the rails cc placed in their carriages d-d.
Fig. 8, in the subjoined cut, is a view of the cast-iron wheel with the malleable iron tire. This wheel is made with curved spokes, as shown at a-a-a, and with a slit or aperture in the rim, shown at b, into which a key is inserted. The reason of this is that on the application of the hot tire, the cast metal expands unequally, and the rim is liable to be cracked, and the rims drawn off, unless the first is previously slit or opened, and the latter curved, which allow them to accommodate themselves to the increased diameter of the wheel; by this formation of the wheel, the tire may be placed on when cold, and keyed up afterwards.
Fig. 9 is a cross section of Fig. 8, through the centre. a-a show the tire; b-b the metal rim. This cast metal rim is dovetailed; so that when the tire, which is dovetailed to suit it, is put on hot, it contracts, and applies itself to the rim with a degree of adhesion which prevents its coming off from the motion of the wheel on the railway. This wheel is of the form to suit an edge-railway; and to make it answer for a plate-rail, it only requires the rim to be flat.
Fig. 10 is an end view of Fig. 8 without the malleable iron tire.
We now proceed to the description of the rolley or learn wheels, designed to move upon a plain railway, as illustrated in the subjoined wood cuts.
Fig. 11 represents a view of a rolley or tram wheel; a-a-a are the malleable iron arms, fastened to the projections hub b on the inside of the rim c-c, by the bolts d-d.
Fig. 12 is a cross section of Fig. 11, through the centre of the wheel; a-a show the arms, c-c the rim, d-d the bolts.
Fig. 13 represents a view of a rolley or tram-wheel, with a plate of malleable iron a-a-a, to form the junction between the nave b-b, and the cast metal rim c-c.
Fig. 14 is a cross section of Fig. 17. a-a show the plate upon which the nave b-b is cast; c-c show the cast-iron rim which is cast upon the plate, the edges of which plate are previously covered with a thin coating of loam and charcoal dust, or other fit substance, to prevent the too intimate adhesion between the iron plate and metal rim, on that if the rim should break, it can easily be taken off, and replaced by casting another on the plate.
Fig. 15 represents Messrs. Losh and Stephenson's plate-railway. At the end of each plate are projections a-a-a, to fit into the dovetailed carriage b-b, and at each end of each plate are projections or tenons c-c, which fall into the mortice hole (in Figs. 16 and 17) in the carriage b-b, and secure the rail from an end motion; and when the pin or key is driven into its place, it secures the plates from rising; and they are thus immovably fixed in their carriages.
Fig. 16 is a front view of Fig. 15.
Fig. 17 is a plan of the carriage, in which, a-a show the boles through which the nails are driven to secure it to the sleeper. When the rails are laid in this carriage, and secured by the pin or key, they keep these nails from starting up, by resting upon them.
Fig. 18 is a cross section of the carriage, and the end of one of the plate rails.
Figs. 23 and 24 are a plan and front view of a rail of the plate-railway (which was at the date of this patent in common use in the North of England) our readers will notice the difference between this and those we previously described.
Fig. 25 represents a front view of the edge-railway in common use at Newcastle prior to 1816; and the portion Fig. 26 shows a piece inclining out of the horizontal position, as they very often do from the yielding of the pedestals causing of course a serious shock to the waggons in passing the joinings on to the next rail."
Messrs. Loch and Stephenson state that their method of joining the parts of their railway together, enables them to sustain a much greater pressure than those which are joined in the usual way; and they avoid the liability to which the ordinary rails are subject - that of the extremity of one rail becoming depressed out of the plane of the adjoining one, and hence of receiving severe blows and shocks, which usually terminate in breakage; and as action and reaction are mutual and contrary, it follows, that if the communication of those shocks to their rails be prevented, the wheels, carriages, and engines, which move over them, are, from the same cause, preserved from derangement and destruction.
As the centre of gravity in a loaded coal waggon is, from its shape, much elevated, the shaking to which the vehicle is subjected by small obstacles, especially such as usually occur at the junction of the rails, causes a considerable portion of the coal to be thrown out; which loss, it is presumed, would be prevented by a more uniform motion of the carriages over a more perfect and stable railway.
It is also worthy of notice, that the plates of the tram or rolley-ways employed in coal mines, are usually fastened down by a single nail passing through a hole nearly at each end of the plate, and entering into a sleeper of wood. These nails, from the vibration of the parts in connexion, caused by the loaded waggons rolling over them, are apt to work loose very soon, and cause a breakage of the plates or rails; to obviate which, Messrs. Losh and Stephenson have introduced the improvements described, and which appear well calculated to effect the object designed.
With respect to the advantages of the wheels described, it cannot be doubted that the introduction of malleable iron arms into cast metal rims has tended much to remedy the destructive results attending the previous use of common cast metal wheels; and that an economy of material and an increase of strength must have attended the change. The rims of wheels thus constructed, may also be case-hardened, without risk of breaking, either in cooling, or afterwards which is not the case when wheels are cast in one piece. It is also unquestionable, that great economy of expense and durability of structure were obtained by the introduction of malleable iron tires over cast-iron wheels because, when the former wear out, the wheels may be re-perfected at a very trifling expense; and the elasticity of the malleable iron has a tendency to moderate and render innocuous the concussions received upon the cast metal.
In what relates to the locomotive engines employed upon railways, Messrs. Losh and Stevenson's invention consists "in sustaining the weight, or a part of the weight, of the engine upon pistons movable within cylinders, into which the steam or the water of the boiler is allowed to enter, in order to press upon such pistons; and which pistons are, by the intervention of levers and connecting rods, made to bear upon the axles of the wheels of the carriage upon which the engine rests."
In the sketch, Fig. 27 represents a cross section of the locomotive engine on the edge-railway: a-a are the steam cylinders, containing the floating pistons b-b, connected with the wrought iron rods c-c, the ends of which rest upon the brasses of the axles of the wheels d-d.
These pistons press equally on all the axles, and cause each of the wheels to press with an equal stress upon the rails, and to act upon them with an equal degree of friction, although the rails should not all be in the same plane; for the bearing brasses have the liberty of moving in a perpendicular direction in a groove or slide, and, carrying the axles and wheels along with them, free the wheels to accommodate themselves to the inequalities of the railway.
The objects of these floating pistons are, to prevent the engine from receiving shocks, and preserve a steadiness of motion; the inventors considering, that by acting on an elastic fluid, they produce the desired effect "with much more accuracy than could be obtained by employing the finest springs of steel to support the engine."
A longitudinal section of this locomotive engine is given at page 401, in the description of Dodd and Stephenson's improvements, which it equally illustrates.
Elijah Galloway, in his 'History of the Steam Engine', states that –
"these locomotive engines have been long in use at Killingworth Colliery, near Newcastle, and at Hetton Colliery, on the Wear; so that their advantages and defects have been sufficiently submitted to the test of experiment; and it appears that, notwithstanding the great exertions on the part of the inventor, Mr. Stephenson, to bring them into use on the different rail roads now either constructing or in agitation, it has been the opinion of several able engineers, that they do not possess those advantages which the inventor had anticipated; indeed, there cannot be a better proof of the doubt entertained regarding their utility, than the fact, that it has been determined that no locomotive engines shall be used in the projected railroad between Newcastle and Carlisle since, had their advantages been very apparent, the persons living immediately on the spot in which they are used, namely, Newcastle, would have been acquainted therewith.
The principal objections appear to be, the difficulty of surmounting even the slightest ascent; for it has been found that a rise of only one-eighth of an inch in a yard, or 18 feet in a mile, retards the speed of one of these engines in a very great degree; so much so, indeed, that it has been considered necessary, in some parts where they are used, to aid their ascent with their load by fixed engines, which drag them forward by means of ropes coiling round a drum.
The steam cylinders below the boiler were found very defective, for, in the ascending stroke of the working piston, they were forced inwards by the connecting-rod pulling at the wheel in turning it round, and in the descending stroke the same pistons were forced as much outwards: this motion or play rendered it necessary to increase the length of the working cylinder as much as there was play its the lower ones, to avoid the danger of breaking or seriously injuring the top and bottom of the former by the striking of the piston when it is forced too much up or down.
As our meaning may not be fully comprehended without elucidation, let us imagine the cylinder of a common beam-engine to be set upon springs which have a play of one feet; the weight of the cylinder, when at rest, depresses the spring six inches; but if the engine be put in motion, then, as the piston ascends and gives motion to the machinery, the springs below the cylinder, being, as it were, the abutments upon which the steam acts, are forced downwards against their seat with precisely the force that the piston exerts in overcoming the resistance of the machinery. In like manner, when the piston descends, as much weight or pressure will be taken off these springs by the same means: the cylinder would, therefore, vibrate or dance upon the bearing springs; and as the motion which it thus obtains is the reverse of the motion then given to the piston, the length of the cylinder should be greater to allow for the extreme vibration to which it is liable.
A quantity of steam would, therefore, be lost in filling up this extra length of the cylinder at each stroke. This would also happen if the cylinder was fixed, as usual, and the carriages of the crank and fly-wheel supported upon springs; and this arrangement would then be exactly the same, in principle and effect, as the parts of the locomotive engine to which we now allude."
In justice to Messrs. Losh and Stephenson, however, we are bound to acknowledge our admiration of the several improvements introduced by them in the carriage wheels and rails, which form to material a part of their specification.
As the two preceding patented inventions of Mr. Stephenson, in conjunction first with Mr. Dodd, and subsequently with Mr. Losh, were united to form one locomotive engine, we could not well separate them. We must, however, now go back six months in our history, to place before the reader some account of a patent granted on the 6th of June, 1815, to that original thinker, "Richard Trevithick, of Camborne, in Cornwall, engineer, for certain improvements in the high-pressure steam-engine, and the application thereof, with or without other machinery, to useful purposes."
The specification contains several "scantlings of inventions" of a novel and ingenious nature, that are foreign to our present object; we shall, therefore, omit these parts, and confine our extracts to those only that appertain to locomotion. After describing a curious species of motive engine, he observes, with respect to a peculiar part of it-
"By putting flat plates or leaves upon the revolving arms within the case, I produce a current of air in the manner of a winnowing machine to blow the fire: and I do sometimes place in the flue a screw, or a set of vanes, somewhat similar to the vanes of a smoke-jack, which screw, or vane, I do cause to revolve by connexion with the steam-engine, for the purpose of creating an artificial draft in the chimney, always proportioned to the size of the fireplace and situation of the chimney. By either or both of these means, I obviate the necessity of a tall chimney, where the engine is used for portable purposes."
Without insisting upon the perfect originality of the principles of this mechanism for exciting combustion, there appears to be novelty in the manner of applying them. But many of our readers will remember that a very few years ago a strongly contested trial at law took place between Mr. Galloway and Lord Cochrane, on one part, and Messrs. Braithwaite and Ericson, on the other, to determine to which of the parties belonged very similar contrivances to the foregoing, which decidedly preceded them both.
The invention of tubular boilers, which are so much employed in locomotion, is popularly considered to have emanated from Mr. Gurney; but the fact will be repeatedly shown in these pages, that he only rendered them the more complex by an additional twist. This remark is drawn from us upon reading Trevithick's specification of 1815, already quoted from. In the extract which we shall next take, it will be seen that he, who was so many years prior to Gurney, did not pretend to be the inventor of tubular boilers, they being, in fact, made fifty years before him. He claimed simply a peculiar modification of them in the words following:-
"And I do further declare that in order to make the boiler of a high pressure steam-engine of very light materials for portable purposes, and, at the same time, strong for resisting the pressure, as well as for exposing a large surface to the fire. I do construct the said boiler of a number of small perpendicular tubes, each tube closed at the bottom, but all opening at the top into a common reservoir, from whence they receive their water, and into which the steam of all the tubes is united."
In a recent Committee of the House of Commons on steam-carriages, it will be recollected, that some of the members were led to believe, by the evidence of civil engineers, that all tubular boilers, or such as held their water in small distinct chambers, were modifications of "Gurneys principle." And the learned Dr. Lardner considered that the peculiar merit of the latter was the circumstance that every part of the boiler exposed to the action of the fire was filled with water. Those gentlemen were of course unacquainted with the foregoing.
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