Page:Encyclopædia Britannica, Ninth Edition, v. 20.djvu/253

RAILWAY 235 passenger station, the Great Western, and the South-Western sta- tions are examples of the first class ; the London Bridge, Cannon Street, Charing Cross, and Victoria stations (comprising the South- Eastern and the Brighton lines), and the Great Eastern and the Fenchurch Street stations (comprising the North London, Black- wall, North Woolwich, and Tilbury lines), are examples of the second class ; and the London and North-Western station is an example of the third class. The first and usual class of stations commands the greatest length of setting -down pavement, ample space for booking and other offices, waiting-rooms, &c., and the shortest average distance for passengers and luggage from the offices to the outgoing trains. Nevertheless, where the traffic is various, involving the despatch of numerous trains to different points in quick succession, and necessarily with perfect regularity, the second system is the best. But where the frontage is limited, and where trains start at some distance from the entrance, there is inconvenience in the movement of luggage over a crowded platform. The third plan is probably the least commodious of the three ; but it has the advantage of affording two arrival platforms, with car- riage-roads alongside, the others having but one so situated. In all the classes, it may be observed, transverse lines are inserted with turn-tables, to place all the lines in compact communication for turning on or off spare carriages, loaded horse-boxes, or carriage- trucks. Independently of the turn-tables, the lines of rail are con- nected by switches or points converging towards the two main lilies of rail, outgoing and incoming ; and thus the assortment and marshalling of trains may be effected by horse or engine power independently of the turn-tables. Each plan of station comprises one or more large turn-tables for reversing the engine with its tender together. The correct arrangement and appropriation of t"he several lines of railway in a terminal station materially affect the economical and efficient working of the traffic. It is essential that every traffic line, both in and out, should be provided with one or more spare sidings, in addition to those set apart for the break-vans, horse-boxes, and carriage-trucks, and for the locomotive department. All these lines should communicate with each other by means of points and crossings, to allow of shunting with engine-power, and to reduce to the lowest limits the number of turn-tables or their substitutes. Curves ought never to have a radius of less than 800 feet. it: The practice with regard to the height of platforms above the ra rails has varied considerably, the tendency being to raise them much higher than was usual at first ; 3 feet may be stated as the limit in this respect. Too much attention cannot be given to the necessity for obtaining the greatest possible width of platform. Where the platform is used on one side only, the width ought never to be less than 20 feet ; and when both sides are required oO, or even 40, should be allowed. The best mode of constructing the platform is undoubtedly with stone slabs laid hollow upon longitudinal walls, so as to admit of carrying beneath it the water and gas pipes, telegraph or signal wires, and the general drainage, with free access to each. Cutting out for turn-tables and openings for cross lines of rails are frequently inevitable difficulties, which have given rise to various ingenious contrivances, as shifting-stages, drawbridges, &c. By far the best substitute for the turn-table yet introduced is the traverser. If well made and carefully worked and attended to, the shifting of carriages from line to line can be per- formed without extra manual labour or interference either with the rails or the platforms. The other objection is best met by the use of easy inclines, with crossings on the rail-level. Where the plat- forms do not exceed 2 feet in height and the surface is smooth, gradients of 1 in 10 are not too steep for luggage-barrows, nor are they dangerous in a crowd. The earlier terminal railway stations were designed either with intermediate columns supporting the roof or with brick walls, vary- ing in number of spans from two to five or six. It often happens that in the course of a few years such stations have to be remodelled to meet the constantly increasing traffic ; and great difficulties are occasionally met with in the rearrangement of platforms which are wasted where lines of rails have been laid, whilst rails are wasted where platforms are placed, and where columns interfere. To allow engines and carriages to pass from one line of rails to another at the shortest possible intervals it becomes necessary to have diagonal crossings from one part of the station to another in many directions, while at the same time the free movements of pass- engers and luggage on the platforms must not be impeded. Thus there arose a system, originated, it is believed, in the great Con- tinental termini, of constructing roofs in two spans, one covering the up lines of rails and the other the down lines. King's Cross passenger station is an example of this kind. The principle of wide spans for the roofs of railway stations, clear of intermediate walls or columns, was adopted in England probably for the first time in 1848-49, in covering Lime Street station, Liverpool, on the London and North- Western Railway, by one span of 153J feet. The extreme length of the roof was 374 feet. The new Lime Street station, it may be added, is covered by a roof of one span of 212 feet. Tythebarn Street station, Liverpool, on the Lancashire and Yorkshire Railway, is covered by a roof in one span of 136 feet ; there, as the traffic increased, the lines and platforms were changed so as to admit of treble the quantity of traffic being conducted, which would have been impossible if the roof had been built with sectional spans and columns. It is averred that the railway com- pany lias been repaid the excessive cost of the single-span roof many times over in economy of working. The next single-span roof on a large scale appears to have been that of 212 feet covering the New Street station, Birmingham, in which five lines of way, belonging to different companies the London and North-Western and others meet and concentrate passenger and goods traffic of every description. The roof was 840 feet in length, with trusses or principals placed at intervals of 24 feet. The principal consists of one arched plate-iron girder 15 inches deep, having a rise of 45^ feet at the centre. The ends of the arch are tied by a round tie- bar 4 inches in diameter, from which the arch is strutted at inter- vals. This is said to cover the largest area of any station in England. The Cannon Street station of the Charing Cross Railway is the Cannon terminus of the City extension of that line, giving direct access to Street the City of London for the South-Easteni Railway, and linking the station. Charing Cross station at the west end with the City. During the year 1867 the first year the extension was open for traffic about 8 million passengers used the Cannon Street station, of which nearly one-half were local passengers booked between Cannon Street and Charing Cross. The length of ground between the river Thames and Cannon Street is 855 feet, of which the fore-court occupies 90, the booking-offices 85, and the shed or covered portion of the station reaching to the river 680. The station is 201 feet 8 inches wide outside the walls and 187 feet inside. The whole of the station is built on a substructure of brick piers and arches, ex- cepting the booking-offices and the part which is over Upper Thames Street. The ordinary piers are 5 feet thick with footings 8 feet wide, resting on a bed of concrete 10 feet in thickness, and the whole of the under structure is made available for storage and other purposes. The rails and platforms are carried across Upper Thames Street on wrought -iron girders 2 feet deep to 37 feet of span. The floor of this bridge is of creasoted Baltic planking 8 inches thick. The walls of the station are of brick-work, 45 feet high above the level of the platform. They are built in piers 6 feet 4 inches thick and panels 2 feet 74 inches thick. The roof is of one clear span of 190 feet 4J inches circular, having a rise or versed sine of 60 feet at the centre, composed of ribs constructed of plate- iron and angle-iron, and, like ordinary girders, 21 inches deep, each foot of each rib being tied by a tie-bar of round wrought-iron 5 T inches in diameter. The tie-bar rises 30 feet and the depth of the truss at the centre is 30 feet. One end or foot of the rib is fixed to the supporting wall and the other end is placed on rollers, by the aid of which the principal or truss is free to expand or to contract according to the variations of temperature. The trasses are placed at from 33| to 35 feet apart. The booking-offices, wait- ing-rooms, &c. , are at the end of the station on the ground floor of the building, which above and below them forms the City Terminus Hotel. Parcels offices, stores, cellarage, &c., are provided in the basement, with hydraulic lifts worked by direct pressure from tanks in the towers at the south end. The used water is discharged into tanks about 9 feet above the level of the platform, whence it is again utilized for the general purposes of the station. There are nine lines of way in the station, of which eight run alongside five platforms, and one line is space for stock and for standing-room. The two outer platforms are employed for the short traffic to Greenwich and W id-Kent and to Charing Cross, 13 J feet wide by 522 and 486 feet long respectively. The general departure platform is 665 feet long and 19 wide ; and the two general arrival platforms, one on each side of the cab road, are 721 feet long by 12J wide. On this system there are two lines of rail to each platform, reckon- ing the general arrival platforms as one ; accommodation is thus found for 4788 lineal feet of trains. These nine lines of way con- verge and merge in five lines of way over the bridge for a length of about 600 feet, constituting the station-yard. The first line, on the western or up-stream side, is exclusively for trains proceeding from Cannon Street to Charing Cross ; the second line is for trains approaching Cannon Street, whether from London Bridge, the country, or Charing Cross ; the centre line is exclusively for trains from London Bridge or the country ; the fourth is the main down line ; the fifth, or east line, is for engines going to or from the engine dep6tr at the far end of the bridge, or for engines wait- ing for their trains. The movements of the trains are regulated from the signal-bridge, which crosses the converged lines of way at a distance of about 140 feet from the south end of the station, by means of about forty pairs of points, with twenty-four sema- phore arms, eight of which are for trains outward and sixteen for trains inward. The signal-box on the bridge is 42 feet long and 9 wide, and contains sixty -seven levers, by thirty -seven of which signals on Saxby and Farmer's system are worked, and by thirty the points are worked. Several of the point -levers work the switches at both ends of cross-over lines. The signals lock the points and each other, so that no contradictory signals can be