Перевод с ин. языка «Перевод»,
Английский язык

1) The rails differ greatly in weight according to the kind of traffic which they have to carry when placed in the track. The largest and heaviest rails are laid in the main-line tracks for it is these tracks which carry the largest volume of traffic. 2) The ties on most tracks were almost all of wood and in order to make them last longer they were treated with creosote. 3) The ties are not laid upon the earth for the earth cannot support the track structure. They rest upon a bed of crushed rock or gravel, which is called ballast. Ballast is a very important element of the track for it is the ballast which supports the track structure, holds the track in position and provides needed drainage. 4) The history of railways is more than one century and a half. During this period the track structure has been substantially improved. One of the greatest improvements was the elimination of rail joints. In order to reduce the number of joints the rails are welded into continuous lengths. These continuous or long-welded rails have greater strength and provide a smoother running of trains at far greater speeds. 5) Another improvement which has made it possible to increase speeds on railways is the use of concrete sleepers. Thus in some countries, concrete sleepers have replaced wooden ones on heavily used main lines because of their advantages. Concrete sleepers have a longer life and a far greater weight than those made of wood. The greater weight of concrete sleepers provides the greater stability of track. It is this factor which has greatly contributed to increased speeds.