Page:Encyclopædia Britannica, Ninth Edition, v. 20.djvu/258

240 RAILWAY 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 18,000. 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 mains, ranging from 14 to 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 Pembridge 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- Fig. 26. 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, &c., at the sides. Glasgow The Glasgow City and District Railway will supply important City and links of communication between the railways on the north side of District the river Clyde. The line extends from College station, High Railway. Street, by George Street and Regent Street, crossing Dumbarton Road to the existing Stobcross line, over a length of nearly 2^ 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 18 J feet at the crown ami 27 feet in width, for two lines of way. The covered way is arched over with brick. New We may take the ' ' elevated railroads " of New York as an instance York of metropolitan railways for local service above ground. In 1867 elevated the first attempt was made to improve existing means of transit railroad, between the residential and the business quarters of the city by the construction of an elevated railroad worked by a wire rope and a stationary engine. The railroad passed into other hands in 1872, and the New York Elevated Railroad Company was formed. The lines of this and of the Metropolitan Elevated Railroad Company are 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 Dep6t 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 34 J miles of line; 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 2 Jd. 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 earnings. On the Xev York Elevated Railroad the line is supported on square vi ought- iron lattice-work columns let into cast-iron base blocks founded on brickwork and concrete, at distances of from 37 to 44 feet apart. Where 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, 22 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, fixed 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 23 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- lustration 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 sharpest curve on the main line has 90 feet of radius. The gradients con- form, for the most part, to those of the streets, and the steepest gradient is 1 in 50 for a length of 800 yards. The traffic is worked with outside cylinder, four- coupled wheel, bogie-truck locomotives, weighing in working order 19^ tons. The driving-wheels are 3| feet in diameter, ami the FIG. 28.- New York Elevated Railroad. Section. 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 are about one- third of a mile apart ; the platforms are 200 feet long and 1 3 wide. The cost per mile of double way is given by Mr R. E. Johnston as follows : Foundations, columns, girders, superstructure, and permanent way . . t Stations 12,000 Five locomotives 4,000 Twelve cars ~, I;M -> Total per mile 81,378 No payment has been made for way-leave along the streets, nor for compensation to froutagers, 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. PERMANENT WAY. The permanent way consists of rails, chairs, spikes, keys, and sleepers laid in a bed of ballast deposited on the formation. The sleepers or substructure should be bedded on broken stones, cinders, or gravel, at least 12 inches in depth under the sleepers, without