The Working and Management of an English Railway/Chapter 11
The Shunting and Marshalling of Goods Trains.
In working the goods traffic on a line such as the London and North-Western, the trains are so arranged as to run with full loads between the most important points, as from London to Birmingham, Liverpool, Manchester, Scotland, and so on; but the traffic at the intermediate stations is collected by a service of local stopping trains, and conveyed to the large junctions, such as Rugby, Crewe, and Stafford, where the waggons are properly classified and marshalled for transit by the through trains. This operation of marshalling and classifying the goods and mineral traffic into district and station order, as will be readily believed, is one of immense magnitude and difficulty, and the work at the terminal stations, and at the important junctions, is extremely complicated, and carried out at a great cost. It is obvious that, unless the trains were properly marshalled for their various destinations, and the waggons arranged in station order, it is not enough to say that the traffic could only be carried on with the most serious interruption and delay; but it would, in fact, be impracticable to carry it on at all, now that it has attained its present dimensions. As it is, any neglect or omission on the part of the men employed in this duty results in great confusion and difficulty at the junctions and Stations, as the train proceeds on its journey. The extent of the operations required may be gathered from the fact that the London and North Western Company alone have no less than 228 engines constantly employed in this work of marshalling and classifying the trains in the sidings, and that the total number of hours of shunting performed last year by these engines was estimated at 1,989,751, representing a cost to the Company, at 5s. per hour (including wages), of £497,437.
The great importance of performing this work in an effectual manner, and with the minimum expenditure of time and money, has led to the subject being studied and debated perhaps to a greater extent than any of the other problems which railway management has had to deal with. Many plans have been suggested and put in operation, as, for instance, at Camden, where the sidings are laid in parallel lines, with a double line of turn-tables across them, worked by hydraulic capstans; at Willesden, Stafford, and other places, where there are sets of sidings in the shape of a fan, with a shunting "neck," or siding, which represents the handle of the fan; and at other stations where the fan-shaped sidings are adopted, but with a falling gradient, utilised so as to economise power. The "fan" arrangement, either with or without the aid of gravitation, is the one most commonly in use, and its utility is sufficiently apparent if the nature of the operation required to be performed is borne in mind. By its aid a miscellaneous collection of waggons for different destinations can be broken up into sections, each section being placed either by gravitation, by a shunting engine, or by horses, in a separate siding. All the sidings running into a common departure line, it is obvious that the sets of waggons can then be drawn out in any order in which they are required to be marshalled in the trains.
At certain important places throughout the country, as at Shildon, on the North-Eastern Railway; at Chaddesden, near Derby, and at Toton, near Trent, on the Midland Railway; and at Blaydon, near Newcastle, on the North-Eastern, and elsewhere, schemes of marshalling sidings of elaborate construction and great extent have been laid down, and these have in each case their own distinctive features, but they have for the most part been devised to meet the special circumstances of a particular traffic or locality, and probably it is not necessary to enter into a detailed description of them. The most successful experiment which has been tried upon the London and North- Western Railway, and possibly also the most successful in the kingdom, whether with regard to efficiency or economy, has been an ingenious plan devised by Mr. Harry Footner, M.I.C.E., one of the Company's principal engineers, for marshalling the waggons in district and station order by one operation, and by means of gravitation. This plan has been put in operation on an extensive scale at Edge Hill, near Liverpool, and as it is one which would be applicable to any large station or junction where a great number of waggons required to be sorted and marshalled, and where a suitable gradient either naturally existed, or could be easily obtained, a description of the method in which the work is carried on and the results obtained, may not be without value.
Edge Hill, as is no doubt well known, is a place on the outskirts of Liverpool, and is situated on the Liverpool and Manchester Railway, which, as we have seen in an earlier chapter, was the first railway constructed by George Stephenson, nearly sixty years ago. At this point the Liverpool and Manchester Railway, which has its passenger terminus at Lime Street, a mile and a quarter from Edge Hill, is joined by a branch railway running round the city, to the docks at the north end, and also by branch lines running through tunnels, under the city, to the various goods depots at Wapping, Waterloo, and Crown Street, so that it will be easily perceived that as regards goods traffic, Edge Hill is a very important and busy place indeed. This is sufficiently proved by the fact that, at the present time, no less than 534 trains of all descriptions are running in and out of Edge Hill within 24 hours, viz., 273 in, and 261 out, and that it has been found necessary to build there a steam shed or engine-house, which holds eighty engines.
Of course, all goods trains arriving at Liverpool have to be broken up at Edge Hill, and the waggons have to be sorted out for the several depots, whence they are distributed to the various docks and warehouses. On the other hand, the trucks loaded at all the depots have to be sent, in the first place, to Edge Hill, where they are classified and marshalled in trains for despatch in all directions. These comprise what is called the "outward" traffic.
It was about the year 1873 that the Company began to have strongly impressed upon them the urgent necessity for making provision on a very much larger scale than they had, up to that time, contemplated, for the shunting and marshalling of trains at Edge Hill, and that they commenced to carry out, as an experiment, and, to a limited extent, the system which has since been elaborated and extended with such beneficial results. In that year (1873) they found themselves in presence of this state of things—that, while the outwards traffic at Edge Hill had grown from 257,025 tons in 1850 to 1,032,853 tons in 1873, the siding accommodation had only been increased from 1,782 waggons to 3,215 waggons; in other words, the business had quadrupled, while the facilities for dealing with it had only been doubled. It may here be said, that, at the present time, the area occupied by shunting lines and sidings at Edge Hill is 200 acres, and that there are 57 miles of running lines, and siding room for nearly 6,500 waggons.
At the period mentioned it became necessary to consider seriously how the difficulties were to be met, for, in addition to the want of room, the main passenger lines had to be crossed every time waggons were moved from one group of sidings to another (and there were a great many groups), so that there were serious obstacles to be encountered in carrying on the working, and as the safety of the passenger trains always had to be the first consideration, the goods traffic had often to suffer delay.The Company had, at that time, about 70 acres of spare land on the north side of the railway, and available for extension, but to reduce this to the level of the main lines would have involved a stupendous amount of excavation, and the fact that the surface of the land rose from west to east, and that, for a comparatively reasonable outlay, sidings could be laid upon it on a uniform gradient which would enable them to pass over the branch line running round to the docks, which branch line intersected the land, suggested to Mr. Footner a scheme for marshalling by gravitation. In considering a scheme of this kind two things appeared to be essential—first, that in the passage of the trucks
from the top to the bottom of the incline, all the necessary changes in their relative positions should be effected, so that when they reached the bottom they should be ready to go away as properly marshalled trains; and secondly, that there should be some means of stopping, without injury to them or their loads, any trucks which might get beyond the control of the shunters. The mere principle of shunting by gravitation was no new thing, as it had already been successfully adopted for coaling ship? on the Tyne, and for sorting mineral trains at Darlington on the North-Eastern Railway; but Mr. Footner claims as his own the idea of an inclined plane specially constructed in such a way as to sort and marshal a mixed goods train by gravitation alone, without any assistance from locomotive or horse power.The arrangement he devised is shown by the accompanying diagram (Fig. 28 b). The sidings consist of, first, the six upper reception lines at the summit of the incline, holding 294 waggons; secondly, the sorting sidings, 24 in number, and capable of holding 1,065 waggons, into which the waggons, when separated, first run, each siding receiving the waggons for a particular train; thirdly, two groups of marshalling sidings, which owing to their peculiar formation have been christened "gridirons," through which the trucks are filtered so as to make them take their proper order of precedence in the train; and, fourthly, the lower reception and departure lines, which receive the trains in their complete state, and where the engines are attached to take them away. All these, it may be remarked, are laid out in such a manner, with a view to future requirements, that without altering any of the existing lines
the accommodation can be increased, when necessary, by 50 per cent.
The modus operandi is as follows:—On the arrival of a set of waggons in the upper reception lines, the rear brakes are put on, the engine is detached, and then on each waggon is chalked the number of the sorting siding it has to enter. One man carefully inspects the brakes of each waggon, and calls out the chalked number to a second man standing below him, who has to regulate the speed of the descending waggons. This second man passes the number on by hand signal to the shunter lower down who has charge of the points, and who, by moving a lever, turns the waggon into its proper siding. The shunters are provided with brake sticks, which they insert between the wheel and the waggon-frame to steady the waggons in going down, and they also use these implements for letting down the brake levers when required. By the process thus described, each sorting siding now holds a separate train, although the waggons composing it are in indiscriminate order, but by a repetition of the operation, the waggons of each train are separated in the gridirons, and are lowered, one by one, into the departure lines, in the precise order in which they are required to be sent away.
Fig. 28 a also shows the apparatus known as the "chain drag," devised by Mr. Footner for arresting runaway waggons, which may occasionally get beyond the control of the shunters. This consists of a heavy iron chain cable, placed in a wrought iron tank between, and below, the level of the rails; a steel hook attached to the cable is fixed in a loose socket, at the height of a waggon axle, and is worked by a lever which also works a signal. When a train is intended to pass, the hook is lowered by the lever, but if it is desired to stop a waggon, the hook is raised by the lever, and catches the axle of the waggon, and the heavy cable attached to the hook, being drawn out of the tank, by its weight, when dragged over the ballast, soon stops the runaway. During the last twelve years this apparatus has come into use 135 times, and in no case has it failed to stop the waggons, without injury either to them or to their loads, or to the apparatus itself. At the present time there are six of these chain drags in use at Edge Hill, the cables varying in weight from 86 cwt. to 109 cwt.
The gradient of these sidings varies, according to requirements, from 1 in 60 to 1 in 115. For instance, through points and crossings, and round the standard curve of seven chains radius, the gradient is from 1 in 70 to 1 in 100, but on straight lines, where waggons have to. start singly, and enter curves, as, for example, at (1), the lower end of the upper reception lines; (2) the lower end of the sorting sidings ; and (3) the lower end of each siding in the gridirons, the gradient is one in 60. Again, on straight lines, where many waggons move together, and good "runners" compensate for bad, the gradient varies from 1 in 100 to 1 in 115. All the curves are of the same radius (seven chains), so that a shunter, in determining the speed necessary for any particular truck, may concentrate his attention upon it, knowing that the resistance of every curve it encounters will be the same. Speaking generally, the gradients are so regulated that the greatest momentum is imparted where the trucks are required to start quickly, and where there is the greatest amount of resistance to be overcome.
In practice it is found that in shunting by gravitation, no two trucks run exactly alike, some railway companies and private owners keeping their stock in better order than others, and much depending upon the precise condition of the tyres and axle-boxes, the length of the wheel base, the nature of the load, and the description of brake gear employed. Strong winds also affect the running, especially of covered vans lightly loaded; severe frost offers an impediment, while, on the other hand, warm and moist weather renders the rails slippery, and heavy concentrated loads on a narrow wheel base will often run too freely; but there are simple appliances which are found in practice easily to overcome all these difficulties. The shunters, during the day-time, use various recognised gestures to indicate in advance to one another the numbers chalked on the trucks passing down the incline, and during the night, similar information is communicated by the movement of the coloured lenses of their hand-lamps.
During the year 1887, 518,000 loaded waggons were passed through these sidings, in addition to 108,000 empty waggons, making a total (exclusive of special trains) of 626,000 waggons, or a daily average of about 2,000, equal to fifty average trains. There are eighty-three men employed to work the sidings, including nine foremen and inspectors. The various foremen's offices are connected by telephone circuits, and, finally, the whole of the sidings are lighted by lofty and powerful lamps of the Siemen's type, in addition to smaller lamps fixed near each pair of points.
One special advantage claimed by its inventor for this system of marshalling waggons, is that it can be carried out by any active man without previous training, the operations being so simple that the work can be learnt in a week or two, and the only man who is really required to be possessed of geographical knowledge and experience being the one who chalks the numbers of the sidings on the waggons.