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RAILS | MODERN RAILROAD |
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Rail System | Light Rail System | Modern RailroadThe precursors of modern railroads were the wagonways, or tramroads (a tram was originally a coal wagon), built in England as early as the 16th century to facilitate the hauling of coal, ore, or stone from mines or quarries to ports or waterways. Although the first wagonways consisted merely of parallel lines of planks, they enabled draft animals to achieve greater speeds and pull much heavier loads than was possible over the bare surfaces of rutted and often muddy roads. Crossties were introduced in early tramroads to hold the timbers that made up the tracks in place. The wooden tracks were soon improved by facing them with strips of iron, and iron wheels on the wagons came into use. In 1767 a British foundry produced the first cast-iron rails, which withstood heavy loads better than iron-faced timbers. In 1811 a British coal-mine owner was granted a patent on a toothed rail to be traversed by toothed wheels. This rack-and-pinion principle is still applied in auxiliary third rails used in a few railroads, for example, on Pikes Peak in the United States and on some Swiss mountainsides, where cars must be pulled up extremely steep grades (Rail System, Light Rail System, Modern Railroad). Modern rails evolved from the edge rails used in northern England at the beginning of the 19th century. Wagons were held on this type of track by flanges extending downward from the inner edges of the wheels. (Many authorities define railroads and railways, in distinction from tramroads, as lines on which the rails are raised above the roadbed.) After the practicability of the locomotive was demonstrated in 1829, and as locomotives replaced horses, mules, and the occasional stationary engines used to pull cars up grades by means of cables, edge rails came into general use (Rail System, Light Rail System, Modern Railroad). Rails of various shapes were devised. The prototype of those used today throughout the world, except in Great Britain, was the flat-footed T rail designed in 1830 by the American inventor Robert Livingston Stevens, who was the chief engineer and president of the newly established Camden and Amboy Railroad in New Jersey. In this type of design the T-shaped rail stands on a base broader than the head of the T, forming flanges at each side that permit the rail to be spiked directly to the ties. In the United States today the rail is mounted on metal plates, called tie plates, which are wider than the rail's base and prevent it from cutting into the ties (Rail System, Light Rail System, Modern Railroad). The bridge rail, which in cross section formed an inverted U and which fitted over longitudinal timbers, was used on the Great Western Railway in England until 1892. Standard in Britain today is the bullheaded rail, evolved from an I-shaped rail introduced in 1835. In theory the I rail (called a double-headed rail) could be reversed when the upper side became worn, but in practice this economy could not be effected, because the lower part of the rail also became worn by contact with the heavy metal braces, called chairs, that are required to hold the rail in an upright position. The bullheaded rail has a wider, thicker head than the I rail but also must be mounted in chairs, in which it is braced by wooden wedges (Rail System, Light Rail System, Modern Railroad). Rail System | Light Rail System | Modern Railroad |
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Rail System | Light Rail System | Modern Railroad |
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GOVERNMENT REGULATION OF RAILROADS: • INTRODUCTION • STATE REGULATION • FEDERAL REGULATION • EARLY 20TH-CENTURY REGULATION • THE DEPRESSION YEARS • POSTWAR ENACTMENTS • DEREGULATION MOVEMENTS |
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