Page:Encyclopædia Britannica, Ninth Edition, v. 20.djvu/259

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RAILWAY 241 any clay or other material in it that might interfere with the drainage of water through the ballast to the formation. Gauge. The measure of the standard or British national gauge of railways is 4 feet 8^ inches of width between the rails forming a line of rails or a way. There are many other gauges in existence in different parts of the world. In England the gauge of 7 feet, originally adopted on the Great Western Railway, was known as the "broad gauge" in contradistinction to the ordinary gauge of 4 feet 8 inches, which was for a long time known as the " narrow gauge." But the 7 feet gauge has been to a great extent replaced by the 4 feet 8J inch or national gauge, and it is being gradually replaced altogether. The lengths of line now (1885) laid on the two gauges on the Great Western Railway are as follows : Miles. Yards. 7 feet gauge 183 924 Mixed gauge 243 1034 4 feet 8 inch gauge 1789 594 ,, ,, joint, half the length being taken as in the Great Western system 84 946 Total length of line 2300 1738 The name of "narrow gauge " has now ceased to be applicable to the standard gauge, and is reserved for gauges of much less width, the metre gauge and others of from 2 to 3 or 3 feet wide. Why a fractional measure of gauge should have been selected is a question which has puzzled many people. The fact seems to be that the track of the original carts or trains 5 feet wide outside the wheels was taken as a standard for the gauge of rails, which was measured outside also. The width of the single rail at the top being originally If inches, the width for the two rails together is 3^ inches, which leaves 4 feet 8J inches for the inside measure or true gauge. There are in the United Kingdom a few railways of gauge narrower than the standard gauge, of which instances occur in the following lines : Festiniog, 1 foot 11 inches ; Talyllyn, 2 feet 6 inches ; Dinas and Snowdon, Southwold, Isle of Man, Manx Northern, Ravenglass and Eskdale, Ballymena and Larne, each 3 feet. The following statement (Table XX VI I.) comprises the gauges of the principal railway systems in the world : Great Britain standard gauge Ireland, standard gauge .... Central Europe, prevailing gauge . . ... ft. in. 4 8i 5 3 4 Si 5 14 8i 13 6 5 6 2 3 5 6 3 3| 3 6 3 6 4 8i (-5 6 4 Si (3 6 14 SJ 13 {Prevailing gauges ft. in. (4 Si 149 6 5 3 2 /5 6 1 4 8i 14 2 (f 6 (53 15 6 (5 3 136 3 6 4 8i 5 3 (53- 13 6

Russia, standard gauge

Spain and Portugal, standard gauge Chili Antwerp and Ghent India, prevailing gauge .... ,, metre gauge ,, Arconum and Conje- veram Railway .... South Australia Egypt Queensland Canada . . . New South Wales Mexico New Zealand The relative advantages of broad gauges and narrow gauges were exhaustively discussed at the Institution of Civil Engineers (in 1873), on the reading of Mr W. T. Thornton's paper on " The Relative Advantages of the 5 feet 6 inch Gauge and of the Metre Gauge for the State Railways of India." The fallacy pervading the arguments for narrow gauges is that they take the width between the rails as the basic unit of the system ; whereas that is really little more than an incident, and the dimensions of the railway must in point of fact be governed by the size and weight of the vehicles which the traffic requires. Speaking generally, the national gauge of 4 feet 8| inches is at least as good as any other for the purposes of general traffic. If the width of gauge were still an open question, it might be maintained that a gauge of 5 feet would be rather more convenient in view of the increasing size of the more powerful locomotives. JRails. "The experience of the last twenty-five years," said Mr George Parker Bidder, speaking in 1861, "has shown that one system has been adopted almost universally the double-headed rails, upon chairs with cross sleepers, a plan which has been materially improved by fishing the joints." On the continent of Europe and in America, however, engineers have almost universally laid the fiat-foot or flange rail ; and in France double-headed rails, keyed in chairs, have been replaced by flange rails. On the Metro- politan and Metropolitan District Railways, on the contrary, the flange rails have been taken up and replaced by double-headed rails in chairs. The case may be briefly stated in the following terms. The double-headed rail system with chairs is the best where sup- plies of material and labour for maintenance and repair are always ready and available. The single-headed flange rail system is the best when the main thing to attain is simplicity in construction. Steel rails are now very generally used instead of iron ; and indeed Steel it may be affirmed that but for the introduction of that material rails, for rails and also for the wheel tires of locomotives the railway system would have broken down under the enormous growth of traffic. Rails of wrought-iron on the early railways lasted about twenty-five years ; those of later date have been worn out in from five to ten years and in certain situations in twelve months, mainly owing to increased traffic, heavier loads on the engine-wheels, in- creased speed, quicker stopping and quicker starting. Steel has come to the rescue both in the engine-wheels and in the rails. Loads of from 15 to 18 tons are now placed with impunity on the single wheels of engines as well as on coupled wheels, while it appears from the investigations of Mr R. Price Williams, a leading authority on permanent way, that a fully proportioned bull-headed rail of steel outlasts fifteen or eighteen iron rails. Steel rails are not merely stronger or harder but, owing to their texture, are worn away only by simple abrasion, whereas iron rails separate out into strands as soon as the outer coating that binds them together is worn off. Mr Alfred A. Langley laid down in 1874 samples of permanent way near Stepney station on the London and Blackwall Railway, where upwards of 300 trains a day passed over a single line of way. The weight of each train was on an average about 150 tons, making a total of about 45,000 tons daily over one line of rails. The rails are both of steel and of iron, weighing 80 lb per lineal yard and keyed in cast-iron chairs on cross rectangular sleepers. The greater number of the wrought-iron rails had to be turned after one year and three-quarters, during which period they had worn down about one -eighth of an inch ; but the necessity for re- versing did not arise from the wear itself, but because they gave way in places, either bulging or splitting. The steel rails had worn about one-sixteenth of an inch in the same period. About 27,000,000 tons had passed over the line. The rails generally, indeed almost universally, used for the way Kinds of of railways are the double-headed, the bull-headed, and the flange rails, or Vignoles rails (in the United States, Germany, Canada, and Mexico), the double-headed and the bull-headed rails being keyed into cast-iron chairs spiked to sleepers, the flanged being laid upon and fastened direct to the sleepers. The principal advantage of the flange rail is the facility with which it can be attached to the sleeper with fastenings of a simple description. The disadvantages are that it cannot be turned or reversed when the head is worn, as the double-headed rail may be, and that the rigid attachment of the rail to the sleeper causes a greater degree of disturbance of the way and involves more labour for maintenance than in the case of the double-headed rail. The double-headed rail is made heavier for the same class of traffic than the flange rail ; but it is also stronger and is easily bent to curves, although owing to the mode of attachment to the chairs by wooden keys there is a liability to a slight longitudinal movement of the rails, known as ' ' creep- ing." The bull-headed rail possesses the advantages of the double- headed rail, except that, like the flange rail, it is not reversible. The bull-headed rail is laid on most of the railway lines of England and Scotland ; the double-headed rail is also in use. In Ireland the bull-headed and the flange rails are used. Double-headed and bull-headed rails in English practice are rolled to a weight of from 82 to 86 Ib per yard ; the heads are made from 2 to 2f inches wide ; the webs are from five-eighths to thirteen-sixteenths of an inch in thickness ; and the height of the rail varies from 5| to 5| inches. The rails are now made of steel, in bars for the most part 30 feet in length, with the advantage in comparison with shorter lengths of a more solid road, fewer joints, and less cost for maintenance. They are fixed into massive cast-iron chairs, weigh- Chairs, ing from 31 to 55 ft each, by means of hard wood keys oak. They are canted inwards in their seats at an angle usually of 1 in 20, the better to resist lateral blows from wheels. The chairs are made of considerable width on the more heavily worked lines from 7 to 8 inches, against a minimum of 4| inches on other lines. On some lines the seats of the chairs on which the rails rest are slightly rounded in the direction of the rail ; this forms a com- pensation for slight deviations from the level in the sleepers, but is mainly useful in preventing indentation of the rails by the con- cussions to which they are subject a matter of importance with double-headed rails which are by and by to be reversed. In such cases Mr T. E. Harrison places cushions of hard wood in the chair to support the rails, which are thus effectually protected from indentation ; and, in addition, the trains run more smoothly. The oak keys by which the rails are fastened in the chairs are Keys, generally applied at the outer side of the rail, as the jar caused by the lateral percussion of the flanges of wheels is then less than when the key is placed inside ; but on the Manchester, Sheffield, and Lincolnshire Railway the key is put at the inner side of the rail, and there is this to be said in favour of the practice, that the rails are kept firmly to gauge and the key is less likely to shift. On some railways contrivances are employed to prevent the keys from shifting or creeping out of their proper position in the chair ; these will be noticed in their places. The rails are laid end to end, one-eighth or three - sixteenths of an inch apart at ordinary XX. 31