rails feet inches rail sleepers gauge laid line flange iron
METROPOLITAN RAILWAY - Railways designed for the local service of large cities are neces-sarily either sunk below or mised above the level of the streets. The late Ilr Charles Pearson, solicitor to the City of London, was the originator of the system of intra-metropolitan railways. He worked at the subject from the year 1837. The Metropolitan and the Metropolitan District Railways in and. around London are ex-amples of the underground system. In 1854 the first Act of Parlia-ment was passed ; the works were commenced in 1860 ; the first section of the line - Paddington to Faningdon Street - was opened in January 1863, Mr John Fowler being the engineer. Several con-secutive extensions into the City and towards Westminster and the Mansion House were made at different times, until the "inner circle " was completed in October 1884, thirty years after the passing of the first Act, and twenty-four years after the commencement of thc work of construction. The inner circle of railways as con-structed is the direct outcome of the recommendation of the Lords' Committee of 1863, that they should abut upon, if they did not actually join, nearly all the piincipal railway termini in the metro-polis, completing the circle by a line on the north side of the Thames. The total length of the inner circle is 13 miles and 176 yards. About 2 miles of this length are laid with four lines of rails, and there are twenty-seven stations on the circle at an average distance of half a mile apart. The combined length of the two systems, including the extensions beyond the inner circle, amounted in December 1883 to 40 nines.
The cost of the Metropolitan Railway system, 22 miles in length, in December 1883 has already been stated as £500,000 per mile, ancl that of the Metropolitan District Railway system, 18 miles in length, as £374,000 per mile. In 1871, when the works had been completed and opened from Moorgate Street to Mansion House station, the capital expenditure by the District Railway Company for works and equipment of 7i miles of double-line railway was officially- stated to be £5,147,000 ; and by the Metropolitan Railway Company £5,356,000 on 10i miles, - subject to deduction in respect of surplus lands. The combined cost for 171 miles was at the rate of £630,000 per mile - the greater cost per mile being, no doubt, due to the greater proportion of underground work. The cost of the 11 miles recently opened between Mansion House and Aldg,ate stations was about £450,000, or about £400,000 per mile. The longer axis of the inner circle is about 51 miles in length, east and west, and the shorter about 2 miles long at the widest part, north and south. The line runs at very various levels, traversing the sloping ground that stretches from the river Thames towards the heights of Hampstead and Highgate. Several natural sewers, formerly clear brooks or tidal channels, now covered, are traversed by the railway. They occasioned many difficulties and great out-lay, as they required to be conveyed. across the line iu specially COB-structed conduits. The Ranelagh sewer, for instance, is carried under the Metropolitan Railway at Gloucester Terrace in a brick-built channel 9 feet wide by 8 high ; and over the District Railway at Sloane Square station in a cast-iron tube 9 feet in diameter, supported on wrought-iron girders of 70 feet span. The Fleet Ditell had to be crossed five times. The average level of the rails of the District Railway, which traverses the old bed of the river and the swamps of Pimlico and Bridge Creek, is 13 feet below Thames high-water mark ; whilst that of the northern part, on the Metropolitan Railway, is 60 feet above that datum, making 73 feet of difference of level, and giving rise to heavy works and steep gradients at the west and east ends of the circle. Cutting-s 42 feet deep and a tunnel 421 y-ards in length are found at Carepden Hill on the west ; and cuttings 33 feet deep and a tunnel 728 yards in length at Clerken-well on the east, on gradients of 1 in 75 and 1 in 100 respectively.
The works of construction consist of covered ways, tunnels, and open cuttings with retaining walls. The cost of property precluded the use of ordinary open cuttings with slopes. The covered ways were formed by making open cuttings in the first place and then building " open " or artificial tunnels, and covering them in, so as to restore the surface. The sides of the cuttings were made vertical or nearly vertical, and they were supported by timber framing or poling boards till the masonry of the tunnel was completed. The line from Paddington to Moorgate was made in this way with a mixed gauge - that is, the 7 feet gauge and the 4 feet 81 inch gauge in combination - to take the traffic of the Great Western Railway as well as that of national gauge lines. The covered way was therefore made 281 feet wide and 17 high for the mixed gauge, and the arch is elliptical, built of seven " rings " or courses of brick, with side walls three bricks or 27 inches thiek, on footings 4 feet wide. At the junction of a branch with the main line a " bell-mouth " or expanding arch was eonstructed in which the span was gradually enlarged to 60 feet. The covered way on the extension, where the national gauge alone was laid, was 25 feet wide. The normal or standard type of arched covered way is 15 feet 9 inches high above the level of the rails. The side walls are three bricks or 27 inches in thickness, and the backs of the walls are carried down vertically to the foundation. The arch was ordinarily built with five rings of bricks, making 221 inches of thickness ; but the number of nngs was increased occasionally to eight, nine, or ten rings. The haunches of the arch are backed with concrete. The footings of the walls rest on concrete foundations 30 inches in thick-ness. A drain-pipe 18 inches in diameter is laid longitudinally along the middle of the tunnel. The whole of the tunnelling of the District Railway, of which Mr Fowler was the engineer, was put in with open cuttings. Two trenches 6 feet wide were sunk to receive the side walls, which were built up to a level 4 feet above the springing of the arch. As the construction of the walls pro-ceeded the timbering was removed and replaced by concrete bacldng behind the walls. The earth in the middle, called the "dumpling " or core, was excavated to such a level as to admit of the centering being put into position for the turning of the arch. 1Vhen the arch was built and the centering removed, the dumpling, which had been utilized for transport, was excavated down to the floor-level from the ends, whence the stuff was conveyed away. By this economical method of procedure the only earth and gravel that required to be lifted was that which was excavated in forming the trenthes for the side walls. It was raised by means of steam-cranes travelling on temporary rails laid by the sides of the excavations. Again, the centering for the arch was supported on the core, and was simple and less costly than ordinary centering. The complete arch is shown in section in fig. 23. Inverts, or in-verted arches, were laid in across the bottom, between the footings of the walls, where, from the nature of the soil or from excessive lateral pressure, the floor was thought likely to rise. When there was not sufficient depth for a brick arched way the side walls were made, as shown in fig. 24, of brick and concrete, in bays 8 feet wide, of piers and recesses') spanned by cast-iron girders from 18 to 30 inches in depth, carryin,g jack-arches between them. The average cost of the arch-covered ways, 25 feet wide, was about £40 per lineal yard, as against £52 per yard for the girder-covered way.
On the inner circle there are three tunnels, - the Clerkenwell tunnel, 728 yards long, of which the level of the rails was from 29 to 59 feet below the surface of the ground ; the " widening" tunnel, 733 yards long, parallel to the Clerkenwell tunnel ; and the tunnel under Campclen Hill, 421 yards in length. Even when the utmost precautions are tak-en, tunnelling through a town is a, risky operation. Settle-ments may occur years after the completion of the works ; water mains may be broken in the streets and in the houses ; stone staircases may fall down ; and other un-pleasant symptoms of instability may show themselves. The cost of the tunnel of 25 feet in width was at the rate of £63 per lineal yard. Open cuttings are 281 feet in clear width on the original line of mixed gauge and 25 feet wide on the extensions. The retaining walls are of brick and concrete, in cast-iron struts, according to the depth, are placed between the walls at the upper part to take the thrust. A section of open cutting with two rows of struts is shown in fig. 25. The cost of open cuttings 25 feet wide and 25 deep was, say, £67 per lineal yard, or with one row of cast-iron struts £55 per yard. With two rows of struts for a depth of 42 feet, the cost was .£108 per lineal yard. It was the intention originally to make the stations as well as the railway strictly " underground," and those at Baker Street, Portland Road, and Gower Street were so constructed. At Baker Street a segmental arch of 45 feet span and 10 feet 4 inches of rise extends over the entire length of 300 feet of platform. The cost of such a station, including booking-offices, restorations, and other contingencies, amounted to X18,000. On the extensions the stations were, when the conditions admitted it, placed in open cuttings, roofed. over, 300 feet long, with platforms 15 feet wide. The average cost exceeded that of the same length of ordinary covered way by from £14,000 to £22,000. Not only sewers but gas mains and water mains occasionally demanded very expensive diversions. In passing Broad Sanctuary 2000 feet of gas rnains, ranging from 14 t,o 30 inches in diameter, were diverted ; and in simply crossing High Street, Kensington, 600 feet of pipes of from 3 to 30 inches bore were diverted. In passing a sound building on a good foundation the work was executed in short lengths, with carefully timbered trenches quickly followed up by the con-crete and brickwork of the retaining walls or covered way. Under the houses of Pembiidge Square the side walls of the railway were constructed in short lengths, and to form the roof of the covered way main girders of 25 feet span were slipped between the walls of the houses at convenient places, between which jack-arches were built. At Park Crescent only a floor of old ship timber separates the kitchens from the railway. The permanent way originally consisted of wrought-iron flange rails with longitudinal sleepers and then of steel flange rails ; but these have been gradually re placed by double-headed rails in chairs. Fig. 26 shows a section of the covered way under Queen Victoria Street, with the main sewer underneath and the galleries for pipes, Scc., at the sides.
The Glasgow City and District Railway will supply important links of communication between the railways on the north side of the river Clyde. The line extends from College station, High Street, by George Street and Regent Street, crossing Dumbarton Road to the existing Stobcross line, over a length of nearly 2i miles, almost wholly underground. Of this length 1700 yards, or nearly 1 mile, are tunnelled and 1000 yards are covered way. The tunnels are arched with four rings of brick in cement, to a clear height of 18i feet at the crown and 27 feet in width, for two lines of way. The covered way is arched over with brick.
1Ve may take the "elevated railroads" of New York as an instance of metropolitan railways for local service above ground. In 1867 the first attempt was made to improve existing means of transit between the residential and the business quarters of the city by the constniction of an elevated railroad worked by a wire rope and a stationary engine. The railroad passed into other bands in 1872, and the New York Elevated Railroad Company was formed. The lines of this and of the Metropolitan Elevated Railroad Company arc now worked together by the Manhattan Railway Company. From the southern terminus of the former railway at South Ferry diverge the lines by which the eastern and western sides of the city are traversed. Junctions are made with the Grand Central Dep8t of the New York Central and other railroads, and with the New York City and Northern Railroad. In the beginning of 1880 the elevated system was worked over 34i miles of lino ; in 1884 96,702,620 passengers were carried over the system, averaging 265,000 per day, over half on one line (3d Ave.). Trains run every two minutes in the morning and evening, when the fares are 5 cents or 2id. for any distance ; and in the quieter hours of the day every four or five minutes for a general fare of 10 cents or 5d. The working charges amounted in 1883-84 to 58 per cent. of the gross earning,s. On the New York Elevated Railroad the line is supported on square wrought. iron lattice-work columns let into cast-iron base blocks founded on biickwork and concrete, at distances of from 37 to 44 feet apart.
NY iiere the street traffic is crowded a single row of columns is planted in the line of each curb, on the upper ends of which a pair of longitudinal girders are fixed to carry a line of way, 22i feet high above the street level, as shown in fig. 27, at each side of the street. In other situations the two lines of way are supported at a height of 21 feet on longitudinal girders in the middle of the street, hxed to transverse girders, which span the street and are carried on columns at the curbs. A third ar-rangement is adopted where the columns are planted in the street at a distance transversely of 23i feet, as in fig. 28, each carrying a line of rails at a, height of 18 feet, and con-nected at intervals by arched bracing to steady the structure. In this il-lu.stration the street is occupied by a double line of tramway. The rails are of the Vignoles pattern, of Bes-semer steel, weighing 50 lb per yard, spiked to cross timber sleepers, and guarded by two longitudinal timbers, one on each side of each rail. The clInrnpet nm•vt, nn Innin linn the streets, and the steepest gradient is 1 in 50 for a length of 800 yards. The traffic is work-ed with outside cylinder, four-coupled wheel, bogie-truck locomotives, weighing in working order 19i tons. The driving- wheels are 3i feet in diameter, and the cylinders 12 inches in diameter with a stroke of 16 inches. The cars are of the usual American type, entered from each end, 45 feet long and 8 wide, with seats for forty-two passengers. They are placed on two bogie trucks, and weigh 12 tons. The trains are provided with continuous air-brakes. The stations aro about one-third of a mile apart • the platforms are 200 feet long and 13 wide. The cost per mile of 'double way is given by Mr R. E. Johnston as follows : - Foundations, columns, girders, superstructure, and permanent way k57,696 Stations 12,000 Five locomotives 9,000 Twelve cars 7,6E0 Total per mile R81,376 No payment has been made for way-leave along the streets, nor for compensation to frontagers, though it is known that in the residen-tial quarters traversed by the railroads rents have in many instances, at least, been depreciated to the extent of 50 per cent PEP.MANENT WAY.
The pennanent way consists of rails, chairs, spikes, keys, and sleepers laid in a bed of ballast deposited on the formation. The sleepers ot substructure should be bedded on broken stones, cinders, or gravel, at least 12 inches in depth under the sleepers, without 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 8f 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 8f- inches, which was for a long time known as the " narrow gange." But the 7 feet gauge has been to a great extent replaced by the 4 feet 8i 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 : - Niles. Yards.
osiyustt:emhalf the length being taken as in Tho 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 3f 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-6 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 lf inches, the width for the two rails together is 3-1 inches, which leaves 4 feet 81 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 llf inches ; Talyllyn, 2 feet 6 inches ; Dinas and Snowdon, Southwold, Isle of Man, Maux Northern, Ravenglass and Eskdale, Ballymena and Larne, each 3 feet. The following statement (Table XXVII.) comprises the gauges of the principal railway systems in the world: - 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 Gaurre and of the Metre Gauge for the State Railways of India." The f'allacy pervadinv. the arguments for narrow gauges is that they take the width bet'ween the rails as the basic unit of the sy-stem ; 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 8f 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.
Tbe 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 piths." On the continent of Europe and in America, however, engineers have almost universally laid the flat-foot or flange rail • and in France double-headed rails, keyed in chairs have been repfaced 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 cbairs. The case may be briefly stated in the following terms. The double-headed rail system with chairs is the hest 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 it may be affirmed that but for the introduction of that material for rails and also for the wheel tires of locomotives the railivay 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 fnlly 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 M 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 vrorn 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 I of railways are the double-headed, the bull-headed, and the flange 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 he 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 fo-r 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 tb per yard ; the heads are made from 2f to 2-.1 inches wide ; the webs are from five-eb"hths to thirteen-sixteenths of an inch in thickness ; and the height of the rail varies from 5f to 51 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- C ing from 31 to 55 M 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 cliairs are made of considerable width on the more heavily worked lines - from 7 to 8 inches, against a minimum of 4f 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 tbe 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 Air 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 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 temperatures, to allow for expansion in hot weather. The joints of the rails are united or fished with parallel steel plates lodged within the side channels of ther rails and fastened with four bolts and nuts passed through the web of the rails, and, in order that the fish-plates may take a solid and steady bearing, the entering faces of the upper and lower members of the rails are in most in-stances formed straight and steep, - at an angle of about 2 to 1. For the same purpose the fish-plates are hollow at their inner faces, so as not to be in contact with the vertical members or web of the rails, and are slightly elastic in consequence. Vertical stiffness, also, is of prime importance in fish-plates, which act as bearas fixed at the ends and uniformly loaded, being required to sustain the loads of trains passing over the joints. On some lines, accordingly, the fish-plates are made of greater depth, extending downwards along the lower table of the rail, and are even turned under it, whence they are called clip fish- plates. The chairs are laid on transverse timber sleepers, ordinarily cut from Baltic redwood to a scantling of 10 inches wide and 5 deep, and 9 feet in length, - speaking precisely, only 8 feet 11 inches in length, to secure the timber from import duty. They are most commonly submitted to a preserving process by the injection of about 2/ gallons of creasote into each sleeper. The chairs are fixed to the sleepers by iron spikes or oak trenails, or both, varying in number from two on the lines of lighter traffic to three or four on lines of heavier traffic. On the London and South-Western Railway and on the South-Eastern Railway a compound fastener is used, - a spike driven into a hollow trenail, after the latter is driven into the sleeper. There are usually eleven cross sleepers to each length of rails of 30 feet, making the average distance between the sleepers about 2 feet 9 inches from centre to centre. It is usual to space them apart more widely in the middle portion of the rail-bars (up to 3 feet) and more closely about the joints, with a view to equalizing the vertical resistance of the rails to rolling loads, by supplying a greater degree of support from the sleepers near the joints.
The standard models of permanent way on the double-headed rail and chair system adopted by Mr John Fowler for the Nevt South Wales railways have been already noticed. The rails are shown in section in figs. 29 and 35. The sleepers are of colonial hard woods, chiefly iron-bark timber. They are laid 2 feet 6 inches apart between centres at the joints of the rails, and 3 feet 1 inch apart elsewhere. The upper and lower tables of the rails are curved or rounded in section to a radius of 51 inches, the height of the rail. The entering or overhanging faces of the rail are inclined at a slope of about 1 in 2, forming straight and equally inclined bearings to receive the fish-Oates. The rails, while in course of manufacture, are tested by selecting a few rails of each day's make, from which a portion 4/ feet in length is cut off and placed on iron supports 3/ feet apart, and is subjected to three blows from a weight of 1 ton falling 12 feet each time. The rails are to deflect not less than 6/ inches and not rnore than 71 under this test without showing any signs of fracture. The fish-bolts, as well as the spikes for fastenino the chairs to the sleepers are made of the finest quality of close'fibrous iron. Fifty per eel-A. of the rails were ordered 24 feet in length, 40 per cent. 21, and 10 per cent. 18. The chairs (fig. 30) are 13/ inches long at the sole, 41 wide, and 11 thick at the seat of the rail. Test bars of the metal used for the chairs are cast to a scantling of 2 inches by 1 inch and 3/ feet long. They are placed on edge, on supports 3 feet apart, and are required to sustain a (lead load of 30 cwt. suspended from the centre of the bar without fracture. The spikes are seven-eightlia of an inch in diameter, tapered at the head to the solid bar. The above-described way, as laid in New South Wales, is bedded in bal-last consisting of broken stone 12 inches in depth below the sleepers, broken to a gauoe of 3 inches, boxed up with broken stone of% smaller size to a gauge of 2 inches for a depth of 8 inches. The total depth of the ballast from the crown of the formation is 22 inches. The surface of the formation below the ballast is rounded in cross-section, in order to drain off such water as penetrates through the bal-last,. Grips or furrows are cut and drains laid in where necessary, so that no water is allowed to remain on the line or under the ballast.
The South-Eastern double-headed rail (fig. 31) is keyed into chairs 4/ inches wide and 13i long at the sole. Thez are fixed to the sleeper by two spikes driven into two hollow oak trenails. The sleepers at the joints are laid 2 feet 4 inches apart between centres. The following are the quantities of material for 1 mile of way, single line : - tons. cwt. qr. It.
Chairs 4022 56 11 0 .21 These quantities are considerably less than those of the Midland Railway (which are stated below), as may naturally be the case for a line chiefly of passenger traffic in comparison with one of heavy goods and mineral traffic. The double-headed rails of the North-Eastern Railway, 82 M per yard, are bedded on blocks or cushions of oak placed in the bottom of the chairs, the advantages of which have already been noticed.
The type section of way of the Midland Railway is shown in fig. 32. The forznation is inclined each way from the centre, makino two straight slopes for drainage. The ballast is of strong grad' broken stone, and ashes or clinker, - chiefly gravel. It covers-a width of 26/ feet for two lines of way. It is laid to a depth of 16 inches at the middle of the six-foot, and is formed level with the upper sides of the sleepers between the rails in the four-foot, with a medium depth of 16 inches, or 11 inches beneath the sleepers.
At the outer sides of the mils the ballast is heaped level with the tops of the chairs, or, more precisely, the tops of the keys, and is sloped down to the formation at each outer side. The upper and lower surfaces of the rail (see fig. 33) are curved to a radius equal to the height of it, and the planks are flat, - adapted for taking up lateral blows and mitigating wear. ' The chairs are remarkable for large dimensions, being 7/ inches wide and 15/ long at the sole, which is inches thick under the rail, and for their weight, 50 M each. The cost of relaying 1 mile of single way on the Midland system just described, based on contract prices in 1884, amounts to £1572, 8s. 5d. Deduct-ing credit for old material to the amount of £714, 8s. 3d., the net cost of relaying is £858, Os. 2d. The particulars of quantities, cost, and credit are given in the following statement, prepared by bir Alfred A. Lang-ley, the engineer of the railway : - , The leading particulars of standard double-beaded and bull-headed rails, with chairs and sleepers, are given in Table XXVIII. (see below).
Specimen standard flange rails are illustrated in figs. 35 and 36 in cross section. Leading particulars of flange rails are given in Table XXIX. below.
In the case of the flange rail of the New South Wales Railway (fig. 35) the inward cant of the rails is provided for by planing out by machinery the beds of the rails at the upper sides of the sleepers to the angle 1 in 20 ; and that the mils may be kept in gauge the beds are notched into the surface by as much as the thickness of the flange of the rail. No holes of any kind, either punched or-drilled, are made in the flanges of the rails ; these are fastened to the sleepers by screws and spikes alternately, having projecting heads, by which the flange is clipped and held down. In order to check the tendency to creeping of the rails as well as of the fish-plates, it is intended to flange the fish-plates and to cut a notch at each end of them, in each of which a dog-spike is to be driven into the sleepers. The Great Northern of Ireland rail is similar to Mr Fowler's on the New South Wales Railway, but heavier. The Midland Great Western rail (fig. 36) is peculiarly formed, with a web of taper section, being nine-sixteenths of an inch thick at the head, and thickened to 1 inch at the flange. The bridge rail of the Great Western Railway (fig. 37) is laid on the model originally adopted by Mr Brunel. The rails are only 3 inches high, and are aided in resisting vertical stress by the con-tinuous longitudinal sleepers of large scantling, 14 inches wide and Credits : - Not included in the above : - Ballast for 1 mile of single line, 4000 cubic yards, at 2s, = £400 ; ballast for 1 mile of double line, 7000 cubic yards, at 2s.= £700 ; ballast for a lift of about 3 inches, in relaying 1 mile of single line, 520 cubic yards, at 2s.=£52 ; engine hire, wages of ballast guards, use of waggons, &e., in relaying 1 mile of single line, £50. The lift of 3 inches signi-fies the wear and tear of ballast and the quantity required to be replaced.
The standard rail on the London and North-Western Railway is, like that of the Midland, bull-headed, but less high and wider at the head and the foot and thicker in the web. The chairs have the peculiarity of being ribbed horizontally on the inner face against which the oak key is driven, in order to grip the key. The sleepers at the joints are placed 2 feet 3 inches apatt between centres. The Great Northern Company's standard rail contrasts with the two immediately preceding rails in being less high than either, and having a thinner web and a larger bead than the others. There are peculiarities in the disposition of the way. The first is that the joints of the rails are supported in a chair directly under each joint, to which the fishes are bolted ; the second is that the two inches ; and, contrary to usual practice, the oak keys for securing the rails in the chairs are fixed on the inner side of the rail, the rail taking its bearing directly upon the jaw of the chair. Thus the lateral strokes of the wheels on the rails are resisted directly which pass throngh their flanges and the sleepe.r together. At the joints they are fortified by square iron plates laid under the joints, through which fang-bolts are passed. The longitudinals are con-nected and kept to gauge by transoms or cross-ties at intervals.
The minimum weight of ordinary flange rails is about 45 lb per lineal yard. If the weight is less than this for main lines the upper bearing surface is objectionably narrow, and it is scarcely high enough above the sleepers. The maximum weight of flange mils is about 80 M per lineal yard. Flange rails, like headed rails, are laid on transverse sleepers, to which they are fixed, most com-monly by means of screws, spikes, or flange bolts and nuts. In all cases it is preferable to effect the fastening of steel rails without piercing them in the flange, as they are materially weakened by such perforations.
In the United States (also very largely in Germany, Canada, and Mexico) the Vignoles rail is universally used for railways, varying in weight from 67 or 70 lb per yard on a few leading lines to 30 lb on narrow-gauge railways. No railroads with any considerable traffic are now laid down with rails of less weight than 60 M per yard. The Pennsylvania Railroad, laid to a gauge of 4 feet 9 inches, is constructed of flange rails of two sections, one of 60 /t) per yard 44, inches high, the other of 67 lb 4i inches high, in lengths of 30 feet. The fishes or splices are 2 feet in length, held by four bolts and nuts. The outer splice is formed with a horizontal flange or " tmre'" which overhangs the flange of the rail and is spiked to the s eeper. Allowance for expansion when the rails are laid in winter is provided by laying the rails five-sixteenths of an inch apart, endwise ; in summer a space of only-one-sixteenth of an inch in width is allowed. The cross sleepers are 8 inches wide by 7 deep, and are 8i feet in length ; they are laid so closely that the maximum distance apart between centres does not exceed 2 feet. There are sixteen sleepers for each length of 30 feet, and the sleepers at the joints are laid with a clearance of over 10 inches between them. The rails are fastened by spikes to the sleepers at the inside and the outside. The width for the double line of way at the forn3ation level is 31 feet 4 inches in cuttings and on embankments the width of the formation is 24 feet 3 incles, sloping from the centre at the rate of 1 in 20. The ballast is laid to a depth of not less than 12 inches under the sleepers, and is filled in to the level of the upper surface of the sleepers. Where stone ballast is used it is broken uniformly to a gauge of 21 inches in diameter. For double lines of way large stones are placed in the bottom, at the centre, between the lines to provide for drainage ; but the stones are not placed under the ends of the sleepers ; thus water is drained off rapidly.
Metallic Permanent Way. - Metallie permanent way, in which the sleepers are of iron, has been much employed in tropical r, countries, and is DOW to some ex-tent adopted in France and in Ger-many. The oldest and most widely used system of me-tallic way is that of lir H. Greaves, who in 1846 introduced a spherical or bowl sleeper of cast-iron, having the chair for the rail cast on its summit (see fig. 33). Every second pair of sleepers are connected and held to gauge by transverse tie-bars, which pass through and are bolted to them. The form of the sleeper is strong, it holds well in the ground, the chair is not liable to be detached, the whole bearing surface is directly beneath the road, the ballast is kept dry and elastic, and there is a simple means of packing the sleeper through holes in the top, with a pointed rammer from the surface so that the sleeper and the rail can be forced upwards without 'dis-turbing the general bed of ballast. They may also be lowered by taking out a portion of ballast from the interior. Another system, Mr W. Bridges Adams's "su.spended girder rail," is shown suspended by continuous angle-wires, or side wings bolted to it, and bedded -ID the ballast ; and, as the bearing surface on the ballast was approximated to the bearing surface of the rail, a great degyee of stability was anticipated. Wrought-iron trans-verse sleepers were first tried in Belgium in 1862, then in France and in Portugal, and afterwards JD Germany. There are various systems, most of which were' unsatisfactory, but the Vautherin sleeper, first tried in 1864 on the Lyons railway, has been successful. It is hollow in section, of the form A truncated, supposing the upper part of the letter to be removed, presenting a flat bearing surface, 31 inches wide, for a flange rail. It is 8 feet in length and 9 inches wide over the flanges forming the base. It is three-eighths of an inch thick at the centre and is only half that thickness in the wings. The rail is fixed to the sleeper with gibs and cotters. It has been reported that the motion over the Vautherin sleepers is much easier than that over sleepers of oak, and that in consequence the cost of maintenance is comparatively low. It is stated that amongst a number of mils laid for trial under sitnilar conditions, some of them on wooden sleepers and some of them on Vantherin sleepers, the number of defective rails amounted to only 2f per cent. of those laid on Vautherin sleepers against 13 per cent. of those laid on wood. It was found that if the Vautherin sleepers were not at least 8 feet in length they failed at the ends, and that even for this length it was expedient to strengthen them at the angles. It was also found that large and hard ballast, or broken stoile3 or broken slag, aggravated the tend-ency to give way. Ballast of ashes produced a similar bad effect, and also caused the sleepers to rust. On the contrary, ballast of gravel, of a marly character, adapted itself admirably to the form of the sleeper. The system of fastening the rails to the sleepers by gibs and cotters has been abandoned in favour of clips and hook-bolts. The Hartwich system of iron way need not be described here, having always given bad results. The Hilf system of iron way consists of two parts, - an iron longitudinal sleeper and a flange rail of steel. It is simple, easily laid and maintained, and econo-mical. The sleeper is in section like the letter E, bevelled at the angles, having an upper flat surface and three flanges downwards. It is 12 inches wide and about 24 deep ; and it can be rolled to lengths of 30 feet and only one-third of an inch in thickness, and to a weight of 59 lb per yard. The rail is 4.32 inches high, with 2.32 inches width of table, 3.40 width of flange base, and four-tenths of an inch thickness of web. It is rolled in lengths of 30 feet and weighs 51-i tb per yard. It is fish-jointed and is fixed to the sleepervith two rows of bolts and nuts at intervals of from 30 to 40 inches. The gauge is preserved by means of 1-inch tie-rods, screwed at both ends with nuts. One tie-rod is sufficient for each leng,th of rail. The combined rail and sleeper, placed on supports 54 inches apart, can carry 18 tons at their middle, without im-pairing their elastic strength.