Building the railroad

Before a railroad is built there are usually several alternative routes to be considered. Maps,

aerial photographs, and profiles1 showing the features of each route are prepared and carefully

studied. Experts then choose what they consider to be the best route. The choice they make has

much to do with the success or failure of the new railroad line. One route may be fairly level,

requiring only a few cuts through hills and fills through valleys. Such a route, however, may require a long tunnel to get through an intervening mountain or several expensive bridges to get over rivers.

This would make it more costly in the end than one with moderate cuts and fills all the way.

Another route, though less expensive to build, may run through unsettled country. Hence it may be wiser to build the more expensive line for the sake of the greater local business it can get.

The selected route is then surveyed carefully, and building commences. Sometimes work parties

begin at each end and build toward the middle, as was the case with the transcontinental railroad in the United States. The constructed sections of track carry trains with supplies for the construction workers. Today parties can be stationed at various points and receive supplies from other railroads already built nearby. This method gets the road finished and earning money much more quickly.

The first step is the preparation of the roadbed2. Following the stakes3 and plans set up by the

surveyors, the working parties clear away trees, make cuts and fills, and otherwise prepare the way.

Other workers set up bridges and dig tunnels. As fast as the roadbed is ready, crossties and rails are laid, either by hand or by machines. Working on level ground, tracklayers can complete several miles in a day. Finally, the track must be ballasted, preferably with gravel, cinders4, or broken stone.

In the United States the usual practice was to build a single-track line with as few tunnels,

bridges, and expensive cuts and fills as possible. Then the track was doubled, first at portions where most trains passed and finally over the entire route, and thus the railroad grew into a first-class line.

This method was largely responsible for the development of great railroads in the United States.

Companies built roads through the open frontier. Soon communities5 appeared along the lines, and new businesses were started. These enabled the railroads to prosper. While track undergoes constant maintenance and improvement, there has been very little new construction in the United States in recent years, and it is estimated that the existing track system could carry 25 percent more traffic. In some areas, new communications and train control systems have allowed the elimination of double tracks in favor of single-track operations.

Notes:

1 profile – чертёж ж/д пути в вертикальном разрезе

2 roadbed – земляное полотно

3 stake – опорный столбик, веха

4 cinder – шлак

5 community – населённый пункт

Дата добавления: 2017-02-01