Engineers and Mechanics Encyclopedia 1839: Railways: Benjamin Thompson

Many other plans have been suggested for employing gravity as a moving power. With a view of improving upon the various contrivances for surmounting the natural difficulties of a hilly country, Benjamin Thompson, late of Ayton, Durham, took out a patent dated October 24, 1821, for "a method of facilitating the conveyance of carriages along iron and wood railways, tramways, and other roads;" in the specification of which, be states, that it consists in the application or use of two, or more, fixed engines, placed upon the railway, or other road to be used, at such a distance from each other as the nature of the line chosen shall render most convenient, and in such a manner as that the action of such engines shall be interchangeable and reciprocal.

Mr. Thompson says, that – "whether the line of road rises or falls, much or little, is level or undulating, matters not; the carriages, loaden and empty, are made to pass in both directions with a uniformity of progress, and at the same time with a despatch not heretofore known. A road on which my invention is about to be applied, must be divided into stages, attention being given, in determining their distances, to the nature of the line, in regard to curves or bends, and to the undulation of the surface. The nearer it approaches to a level, and the fewer, as also the easier the bends are, the better will it allow of the stages being extended.

“On the other hand, should the line prove to be a very uneven one, with frequent and short bends, then the intervals or spaces between stage and stage will necessarily be required to be shortened accordingly. I shall probably be able more clearly to explain my method by describing a supposed case.

“Let the supposed road, to which my invention is to be applied, be a railway (either already in being, or to be made,) from a colliery to a staith, seven and a quarter miles in length. A proper survey being taken, and a plan and section of the line made, I find it to be expedient to divide it into five stages, in the manner shown by the drawing annexed.

“The first stage of the colliery may be formed to a tolerably uniform ascent, by the aids of cuts and batteries, of one and half inch to the yard, being three-quarters of a mile in length, and terminating at a summit, on which is to be erected a steam-engine, of power sufficient to draw up the plane six loaden coal waggons at once, containing a Newcastle chaldron each, at the rate of seven and a half feet per second. This stage is a regular inclined plane, and is to be wrought according to the first of the modes already described as now in use; for the returning empty waggons will pass downward by their own gravity, and take the rope with them, preparatory to the drawing up of another load. set. The full set being drawn up in eight minutes and forty-eight seconds, the empty set allowed to pass down in seven minutes and eighteen seconds, and three minutes occupied in the changes at the ends, will cause one operation of the plane to be completed in nineteen minutes and six seconds.

“The engine which I call No. 1 is the first station.

“The second stage lies over a variable or undulating surface, the two extremities of which are distant one mile and three-quarters, and stand nearly level with each other, the intermediate country, not admitting, but at too great a cost, of the line being rendered level; the ascents and declivities are moderate, neither exceeding one inch in the yard; and the curves or bends are easy, and not numerous. A steam-engine, No. 2, is erected at the farther termination, which is the second station, to be used tor drawing twelve loaden waggons along this stage at once at the rate of eight and three-quarters feet per second, and bringing along with them a rope from No. 1 engine, which is allowed to run off a wheel, not connected with No. 1 engine, during their passage to No. 2 engine; upon their arrival at which, twelve empty waggons are substituted, which are drawn back to No. 1 by the reconnexion of the rope-wheel with that engine, bringing with them a rope from No. 2 engine, which is, in like manner, suffered to run off a wheel, then thrown out of connexion with No. 2 engine. The operation of this stage, both from and towards the colliery, is thus carried on by the alternate action of Nos. 1 and 2 engines, standing at its extremities. The passage of a set of waggons takes up seventeen minutes and thirty-six seconds each way, and the changes three minutes; making together, for a completion of the operation, thirty-eight minutes and twelve seconds, or double the time taken by a net of half the number on the first stage.

“The third stage is also one mile and three-quarters long, and very similar in regard to plan and section to the second stage. A steam-engine, No. 3, is placed at the third station, which is the furthest extremity of the stage, to draw the loaden waggons along the same; and the empty ones are to be taken back by No. 2 engine, in the manner which has just been described on the second stage. the speed, and the number of waggons to a set, are the same also.

“The fourth stage is more favourable than the second and third, extending over a gently undulating country, and being nearly straight; the fourth station, or further extremity of the stage, being, in point of level, twenty feet higher than the other end of it. A steam-engine, No. 4, is to stand at the fourth station, to be used for drawing the waggons from the third station. Nos. 3 and 4 engines will thus alternately act to each other on this stage, as Nos. 1 and 2 have been described to reciprocate on the second stage, and also Nos. 2 and 3 on the third stage. The length of this stage is two miles; and twelve waggons are to travel together, at the rate of ten feet per second, which will complete the process of a passage each way, with the changes, in thirty-eight minutes and twelve seconds.

“The fifth and last stage, which is one mile long, declines regularly by the help of cuts and batteries, to the staith, averaging three-quarters of an inch to the yard. The loaden waggons are made to pass down the same, in connexion with the machinery of No. 4 engine, and also during the time of its drawing a set of full waggons along the fourth stage; the waggons along the fifth stage moving with half the velocity of the waggons along the fourth stage, or five feet per second, and consequently performing the journey in the same time. The advantages of this cooperative movement are, that No. 4 engine, being aided by the gravity of the twelve loudest waggons passing down the inclined plane to the staith, requires only about one half the power which otherwise would have been necessary for drawing independently the full waggons from the third station, and the descending waggons themselves are restrained from proceeding too rapidly, and their speed accurately regulated. The engine No. 4 is stood to draw the empty waggons back again from the staith.

“This mode, whereby the gravity of the loaden waggons passing down an inclined plane is applied in aid of an engine for drawing load en waggons forward upon another stage, is quite new, and has never been used before; but I do not claim it as any part of my said invention.

“The second, third, and fourth stages, are those on which my method is applied. Nos. 1 and 2 engines reciprocate, or act interchangeably with each other on the second stage; No. 2 drawing the loaden waggons front the first to the second station, and No. 1 pulling the empty (or in case of need, loaden) waggons back again. Engines Nos. 2 and 3 operate alternately in the same manner with earls other upon the third stage; and so also do Nos. 3 and. 4 on the fourth stage.

“The engines are severally to be furnished with two rope-wheels, and a rope to each, of a length and strength suitable to the stage upon which they are to be stood. The rope-wheels must be so constructed as to allow of a ready connexion, or the contrary, with their respective engines, so as to be capable of being acted upon by them, or of turning round, independently, at the will of the engine man. This may be readily accomplished by any one of the modes in use with mill-wrights for throwing machinery into or out of geer, with a moving power, and does not require to be here described.

“I make use of very light friction-wheels, a-b-c-d, etc. in the drawing, placed vertically, at proper intervals, to bear the ropes from the ground, where the road is straight; and round the curves or bends I place similar wheels, in inclined positions, for the same purpose. Although two miles have been mentioned as the longest of the stages upon the supposed road, it is practicable, under the circumstances of a favourable country, to extend the operation to much longer stages. Without the application of my invention to the supposed road, of which a detailed account has been given, horses would be required to draw the waggons upon the second and third stages, because the ascent of one inch to the yard is too great for locomotive engines to be used upon them, independent of the question as to their effecting a saving at all upon horse labour, on those level roads where they are applicable.

“Upon the fourth, or two mile stage, they might be adopted; but, from the doubt as to an advantage under any circumstances arising by their use, horses would most likely be deemed the more eligible for working it also. Compared with horse labour, my method would, upon those three stages, effect, in all probability, a saving of seventy-five per cent. In cases of greater inequality of surface, the saving would be in a still greater ratio.

“A further and very important reduction in the cost of a new road would result from its adoption. In the formation of a road, it is generally necessary to make deep cuts, and raise high batteries, in order to obtain a uniformly rising, falling, or level surface; and it frequently happens, too, that the direct line of way must be materially diverged from, to favour that purpose. My plan dispenses with such nice attention to regularity, the engines being capable of surmounting acclivities, and the wheels which give out the following or passive rope, affording the means of restraining the too rapid progress of a waggon down a declivity. In short, there is no country, however uneven or variable its surface, but that may, by my method, be traversed.

“For conveying minerals underground, where the unevenness of the strata and their general disposition to undulation do not allow of a uniformly ascending, descending, or level road, my invention is peculiarly applicable.

“Briefly, then, and it will easily be collected from what has been said, ‘My method of facilitating the conveyance of carriages along iron and wood railways, tramways, and other roads,' is the reciprocal action of two engines, standing at the extremities of a stage, or portion of road to be travelled over, one engine drawing the carriages forward in a direction towards itself, and along with them a rope from the other engine; which rope, in its turn, pulls the same or other waggons, by means of the other engine, back again, and also a rope therewith - thus, by the alternately active and passive agency of two ropes, are the powers of fixed engines made to act in opposite directions, thereby causing a road to be traversed both ways, by loaden or empty carriages, at any desired speed. It is the reciprocal and interchangeable application of power, as hath been described, which I claim to be my invention."

The inventor had an opportunity of putting his plan into execution, immediately after the sealing of his patent, at Ouston Colliery, in the county of Durham, and about seven miles from Newcastle, upon a length of line of seven and a quarter miles as in the supposed case mentioned in the specification. The principle was, however, at that time only applied through the medium of two steam-engines, previously used in drawing loaden waggons up inclined planes.

The distance of the two engines from each other was 2,315 yards, the upper end whereof is a steep inclined plane, 323 yards long, up which the carriages were drawn by the Ayton engine; and the remaining portion, which is 1,992 yard; which had previously been worked by ten powerful horses, the ascent of it being 651 feet, but not a regular acclivity. The engine at the lower end was for the purpose of drawing loaden waggons up an inclined plane extending 387 yards in the contrary direction, or towards the colliery. The two engines, in addition to their former work, have been made to reciprocate with each other over the whole length of the horse road (which has considerable curves and irregularities) according to the mode described in the foregoing specification upon the second, third, and fourth stages.

Six loaden waggons, coupled together, carrying the same number of Newcastle chaldrons, or 15 tons 18 cwt. of coals, pass upward at a speed of 105 feet per second, or 7 miles an hour, with the greatest ease and certainty, affording a despatch by no means derived previously from the use of animal power. The two extremities being visible to each other, are furnished with flags, to give alternate signals of the readiness of the waggons to proceed. When the atmosphere is hazy, and the flags cannot be seen, signals are made by drawing forward the rope three or four yards with the engine, at that end which the waggons are intended to go, and which is instantly perceived at the other end. And in the dark, (for the work is daily prosecuted during five or six hours' absence of light during this period of the year,) signals are given by a fire kept up at each end for lighting the workmen, which is shut from, or opened to, the view of the opposite extremity by means of a door.

A person accompanies the waggons constantly, seated in a chair fixed securely upon the fore end of one of the soles of the leading waggon of the set, which is easily removed from one to another. The use of such attendant is to disengage the hauling rope from the waggons by means of a spring. cable, in the event of any sudden emergency, such as the breaking of a wheel or rail, or the hazard of running down any object, the stage in question lying over a common.

Friction wheels of cast-iron, weighing 14 lbs. each, having an axis of malleable iron, turned in a lathe, and weighing 1 lb. and running upon a frame of oak, are placed eight yards asunder, on the straight parts of the way, and five yards from each other along the curves. For the latter purpose they are put into frames of iron and wood, which allow of an inclined position to any angle. The requisite inclination of the wheel, or that which is best suited to the curvature of the road, is soon found out by the road-wrights. The greatest deviation from a vertical line found necessary in the present case, was 45 degrees. The angle properly adapting the leaning friction-wheel, is that which allows of neither an upward or downward stress of the rope, but which presents the wheel in such a manner as that the strain of the rope shall be in a line at right angles with the axis.

The friction-wheels are 11 inches diameter, with a groove 2.5 inches deep, opening from a narrow bottom to 4.5 inches at the top. The inclining wheels have a cast-iron horn projecting 5 inches from the frame slits under side, to receive and guide the rope into the groove. The wheels are all made to run upon oak bearings, and are greased once every day; they act well, and run in the lightest possible manner, occasioning a friction incredibly small when their number, (350,) and the length and weight of ropes, are considered; for in order to preserve and keep safe the ropes, they are both housed every night, the last set of loaden waggons being drawn up without the tail or passive rope, and in the morning that rope being first conveyed upwards with a single empty waggon by a horse, which performs the task without difficulty at the common working pace of 2.5 miles per hour.

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