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III. Check yourself

1.What is one of the basic features of railways?

 

The track is one of the basic features of a railway. It is also called the permanent way

2.What were the stages of railroad building in the early days?

 

The fact is that in the early days of railroad building the workers first had to lay temporary tracks to transport the materials to the construction site. And only after that they laid down the permanent tracks or the permanent way, as it was called. The permanent way consists of rails, ties, and ballast.

3.What is the difference between the modern railroad track and the first one?

 

The railroad track of today is quite different from that used in the early days of railways. The first tracks had no ballast, the rails were made of wood and rested on heavy blocks of granite. Then the wooden rails were replaced by iron ones, and the granite blocks were replaced by wooden ties or sleepers.

4.What does the word "gauge" mean?

 

The distance between the rails is called the gauge.

5.What is the standard gauge in most countries?

 

The standard gauge in most countries is 1,435 mm while in Ukraine the railroads have a gauge of 1,520±4 mm.

6.In what country was the gauge unified in 1886?

 

7.What is the weakest part of the track? Why?

 

The place where the ends of the rails meet in the track is known as the rail joint. The rail joint has always been the weakest part of the track for nearly all the rails wear out first at the ends.

8.How many tracks do railroads have?

 

Some railroads have two or more tracks in order to make the trains pass from one track to another the railroads have a switch which is a very important element of the track.

9.Why are the heaviest rails laid in the main-line tracks?

 

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.

10.How do the rails differ according to the kind of traffic?

 

The ties on most tracks were almost all of wood and in order to make them last longer they were treated with creosote.

11.Why are the heaviest rails laid in the main-line tracks?

 

The largest and heaviest rails are laid in the main-line tracks for it is these tracks which carry the largest volume of traffic.

12.What makes wooden ties to last longer?

 

The ties on most tracks were almost all of wood and in order to make them last longer they were treated with creosote.

13.Are the ties laid upon the earth?

 

The ties are not laid upon the earth for the earth cannot support the track structure.

14.What does the ballast mean?

 

They rest upon a bed of crushed rock or gravel, which is called ballast.

15.What is the function of the 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



16.What rails have the greater strength?

 

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.

17.What do they provide?

 

These continuous or long-welded rails have greater strength and provide a smoother running of trains at far greater speeds.

18.What improvement made possible to increase speeds on railways?

 

Another improvement which has made it possible to increase speeds on railways is the use of concrete sleepers.

19.What advantages have the 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.

20.Does the greater weight of concrete sleepers provide the greater stability of track?

 

The greater weight of concrete sleepers provides the greater stability of track. It is this factor which has greatly contributed to increased speeds.

 


Date: 2016-01-14; view: 1310


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