TRAMWAY. Originally a tramway signified a wheel track laid with timbers, and afterwards with iron plates, having a flange on the inner edge by which wheels of the ordinary sort was kept in the track (see RAILWAY). The introduction of the flanged wheel and edge rail caused tramways to be superseded by railways, but not until many miles of tramroads had been laid and successfully worked in various parts of the United Kingdom. Although the name is sometimes given to a light railway, by a tramway is now generally understood s street railway, constructed so as to interfere but little with the ordinary traffic, on which vehicles having flanged wheels are propelled by animal or mechanical power. Tramways in this sense originated in the United States.

A street railway for passengers was laid in New York in 1832, but it was soon removed on account of the accident caused by it. In 1852 a French engineer, Loubât, revived tramsways in New York, and they were soon afterwards laid in other American cities. A short line was also laid in Paris in 1853. The rails used were of wrought-iron, 5 inches wide, having a groove for the flanged wheels of the cars 1 _ inches wide and 1 to 1 _ inches deep (fig. 1). To lessen the inconvenience to ordinary traffic occasioned by this rail, the "step rail" (fig. 2) was introduced, consisting of a flat surface 3 to 5 inches wide, which can used by ordinary wheels, and a raised tread on the outer side 1 inch higher and 1 _ inch wide, on which the flanged wheels of the cars run. This form of rail is still very general in American, and is a good one for the tramways, though not for the general public. In 1858–9 Train, an American, endeavoured to obtain an Act of Parliament authorizing tramways in London ; failing in that, he laid tramways, by consent of the road authority, first in 1860 at Birkenhead, and soon afterwards in London. The rail laid at Birkenhead had a step of _ inch between flat surfaces 3 inches and 1 _ inches wide. That laid in London was narrower, with a step of half an inch, but the slippery flat surface and the step of the rail caused serious inconvenience and numerous accidents to carriages, and the tramways were removed in a few months, after one of them had been successfully indicted as a inconvenience until 1864, when, after a short length had been laid as an experiment with a rail of the grooved section now in general use (fig. 3), the whole of the tramway, several miles in length, was relaid with it. The tramway was subsequently indicted as a nuisance, but the trial resulted in a verdict in favour of the grooved rail. In 1868 an Act of Parliament authorizing the construction of about 6 _ miles of tramways in Liverpool was obtained ; and in 1869–71Acts for 61 miles of tramways in London were passed, and were soon followed by other Acts for tramways in Glasgow, Dublin, Edinburgh, and other provincial towns.

In 1870 the Tramways Act was passed, enabling the Board of Trade to make provisional orders authorizing the construction of tramways in Great Britain, with the consent of the local authorities, and giving considerable powers for regulating their construction and working. By the Act the gauge, unless otherwise prescribed by special Act, is to be such as will admit of the use of carriages constructed for use on railways of a gauge of 4 feet 8 _ inches. Tramways for which Acts had been previously obtained were of 4 feet 8 _ inches gauge, to comply with a standing order intended for railways, and not to make them available for railway rolling stock, which the narrow groove of an ordinary tramway rail will not admit. There is reason to think that a narrower gauge, such as 3 feet 6 inches, is often sufficient and preferable to the 4 feet 8 _ inches gauge.

Tramways in towns, authorized by provisional order, are to be constructed in the middle of the road, and are not to be so laid that for 30 feet and upwards a less space than 9 feet 6 inches shall be left between the outside of the footpath and the rail, if one-third of the owners or occupiers of premises abutting upon that part of the road object. Vehicles are thus enabled to stop at the road side without hindrance from the tramcars. To leave 9 feet 6 inches on each side of a single line of tramway of 4 feet wide. No carriage used on a tramway must extend more than 11 inches beyond the outer edge of the wheels, and there must be a space of at least 15 inches between the sides of the widest carriages or engines to be used, when passing one another. A width of not less than 3 feet 2 inches between double lines and passing places is thus necessary, and a double line of tramway, leaving 9 feet 6 inches space on each side, requires a street at least 32 feet and 6 inches wide between the footways. In narrow roads there is a convenience in having the tramway at the side, and it is sometimes provided for in special Acts. The space between the rails, and for 18 inches beyond them, is repairable as part of the tramway. Power is given to local authorities to purchase tramways at the expiration of twenty-one years, and they may be removed under certain circumstances.

It appears from a parliamentary return that in 1886 there were 779 miles of tramways open for traffic in Great Britain, on which a capital of £11,503,438 had been expended, the net receipts for the year being £563,735, and the working expenses 79 per cent. of the gross receipts.

The grooved rail first laid in England was 4 _ inches wide and an inch thick, having a tread or rolling surface for the wheel 1 _ inches wide, and a groove _ inch deep, _ inch wide at the bottom, and 1 _ inches wide at the top (fig. 3). The rail was spiked through to a longitudinal timber laid on cross sleepers, and secured to them by angle brackets and spikes. The rail and adopted, but it was found that the heads of the spikes wore off, and the rails required re-spiking, and split and worked loose at the joints. A rail known as the box-rail was introduced, having flanges below on each side, through holes in which clips are driven to fasten the rail to the timber. This constitutes a good fastening, and the flanges give stiffness to the rail, but the clips cause gaps between the rail and the paving stones, which lead to the formation of ruts alongside the rails. The longitudinal timbers, instead of being laid on cross sleepers, on which the paving does not bed well, are often fixed on in cast-iron chairs connected by transverse tie-bars. A bed of concrete is always laid under the longitudinal timbers, and should extend to the whole width of the paving. The rails first laid weighed 40 lb per yard, but it was soon found desirable to increase the weight to 60 lb per yard. It is, however, impossible to fish the joints of rails like the above, and it was found that the working of the joints under the passage of the cars loosened the ends of the rails, dislocated the paving, and damaged both the tramway cars and ordinary vehicles. Tramways proved hardly able to withstand heavy street traffic ; and to provice for steam tractioin a stronger form of rail and a better system of permanent way became necessary. Many forms of iron bearings have been devised, the rail being either supported continuously or on chairs at intervals. In the best of these the tram rail can be replaced when worn without disturbing the foundation. In the system used in Liverpool cast-iron longitudinal sleepers weighing 80 and 90 lb a yard carry steel rails of a T section (fig. 4) weighing 40 lb a yard, both sleepers and rails being held down the by bolts jaws anchored in the concrete foundation. The rails can be renewed and the ££

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