Safety and high speeds
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variant I Speak about your research work: You should say the name of it Why you choose it It’s contribution to the railway system II Translate this text and do exercises given below SAFETY AND HIGH SPEEDS I (1) Today’s railways would not be so popular but for the ever-increasing speed. Super-high speeds, however, go hand in hand with safety.Indeed no passenger would dare to go by rail unless the railways were able to ensure safe travel. (2) Safety depends on many factors. First of all, it is determined by the condition of the track. Track-testing cars1 driven slowly along the lines show the engineer where the track must be repaired and a great deal of track main*"" tenancy machines are available to keep the track well maintained. (3) In discussing railway safety consideration should also be given to efficient braking systems. From the very beginning, railway men attached great importance to the problem of stopping trains. At first, the brakes were installed in the locomotives, then they were fitted on passenger vehicles. But the early brakes proved to be entirely unsatisfactory. They were hand-operated and the braking process itself was too dangerous for the brakes men. (4) The most significant achievement in braking trains was undoubtedly made in 1872 when George Westinghouse, an American, suggested that automatic air brakes should be installed in the trains. When Westinghouse first proposed to adopt his brake some experts said they would not waste time on "such nonsense as stopping trains by air". (5) But fate planned a dramatic test for Westinghouse's brake. While undergoing a test the train equipped with the Westinghouse brakes approached a tunnel. Suddenly the driver saw a horse and a wagon on the track directly ahead. Immediately he applied the air brake. There came a scream of metal on metal and the train stopped. It seemed like a miracle! Never before in all the railway history had a train been stopped so fast. (6) Another aspect of the railway safety problem is signalling. The need for signalling arose when the number of trains increased and it was necessary that the train movements should be directed by one way or another. The function of the early signals was to ensure a certain interval of time between trains lest trains should collide. However, the time interval method, as it was then called, soon became unsatisfactory because with the increased number of trains and cases of their late arrival at stations this method could not ensure the interval of space. (7) The result was that another method was devised which came to be known as2 the space interval system. The modification of this method is the modern block system under which the line is divided into short sections or blocks and a fixed colour-light signal is placed at the entrance to each block. The function of the block signal is not to admit a train to a block section if the latter is occupied by another train. II (-8) The most recent method of controlling the movements of trains is known as "Centralized Traffic Control" or CTC.3 The introduction of CTC is sure to be a step forward in the improvement of railway signalling. (9) Under CTC all train movements are governed from a central point where there is a large illuminated panel with a diagram of all the tracks in the controlled section. Below the diagram there are small buttons. Pushing the buttons the operator changes the position of switches and signals. A number of small lights on the diagram show the dispatcher the location of each train. Having the location of all the trains in his section displayed for him the dispatcher can keep the train moving with as little delays as possible. (10) In spite of the reliable signalling system and highly efficient methods of train operation accidents still occur on railways, particularly on high-speed lines. Indeed, no engine driver would be able to read block signals easily at a speed of, say, 200 kph. Weather conditions can also prevent the driver from reading the wayside signals. Sometimes the drivers themselves are not careful enough. This has made the railways change radically the entire system of signalling. The key to solve the problem of train operation has been found in the so-called semi-automatic driving of trains which is indispensable for safe operation of trains moving at top speed. By semi-automatic driving of trains is meant the use of locomotive cab signals4 and automatic train stop devices.5 (11) The cab signal is a small-size colour-light signal placed directly in front of the driver's seat. It gives the same signal indications as those given by the block signal. The advantage of the cab signal is that it is not affected by weather conditions. Under this system, a sound warning is given to the driver whenever the speed should be reduced. Should the driver ignore6 the warning, for any reason, the protective device will decrease the speed of the train or bring the train to a stop without the action of the driver. (12) From what has been said above it follows that careful track maintenance, efficient brakes and reliable signalling are the factors which assure safe running of trains at high and super-high speeds thereby increasing the track carrying capacity and improving the utilization of the rolling stock. Exercise 1 Read the sentences and translate them into your native language. 1. We planned that we should conduct tests without delay. 2. If a satisfactory electrical protection had been available, we should have avoided the accident. 3. It is desirable that all new modes of transport should be economical from the point of view of fuel consumption. 4. Experts insist that the initial cost should be determined before the electrification of the line begins. 5. In case of repairs the catenary is sometimes deenergized (обесточивать) lest any accident should happen. 6. We know that a train should not be admitted to a block section if the track ahead is occupied. 7. The designer should have attached greater importance to the scientific principles in designing his bridge. Exercise 2 Define highlighted words meaning and find equivalents them. (1) For many years speed has been the chief goal for railway engineers in many countries. Numerous tests of newly-designed vehicles show that the possibilities of increasing speeds have not yet been exhausted. (2) The ER-200 train is worth mentioning in this respect. Capable of developing 200 kph, the train also meets the requirements of safety and passenger comfort. Many latest achievements of railway technology have been incorporated in new express train. (3) However, it is the contactless transportation systems which seem particularly promising as regards speeds. These systems can be divided into two principal types: the air-cushion system and the magnetic suspension system. The main drawback of the air-cushion vehicles propelled by turbo-jet engines is that they produce much noise and pollute the atmosphere with exhaust gases. As to the magnetically-suspended vehicles, they are silent in operation and do not produce air pollution, which makes them attractive for big cities and suburban areas. Exercise 3 Answer the following questions. What factors determine the safety on railways? 2. What types of railway equipment help the railwaymen keep the track in a good operating condition? 3. Who devised the method of stopping trains by compressed air? 4. Why did the early brakes give way to the Westinghouse brakes? 5. What made railways invent different methods of signalling? 6. What were the main steps in the evolution of signalling and what was the purpose of each method used? 7. What is CTC and how are train movements governed under CTC? 8. What may cause accidents on high-speed and superhigh-speed railways? 9. How is the problem of safe train operation solved nowadays? 10. What is meant by semi-automatic driving of trains? 11. How do cab signals and automatic train stop devices help the drivers avoid accidents? III Write the annotation to the text given above. You could have done much better in the exam … If the weather had been nice … I wouldn’t have bought that book … She would have gone to Japan last summer … If I hadn’t taken an umbrella … That building wouldn’t have fallen down … … if she had spoken Japanese quite well. … if it hadn’t been so old. … if I’d known how dull it was. … I would have got wet. … we could have gone horse-riding. … if you had taken private lessons. V Rewrite the following sentences using the passive voice. My grandfather built this house in 1917. By this time tomorrow, we will have closed the contract. Shakespeare wrote Romeo and Juliet. Michael hired Karen last year. Someone should finish the project. We had lost all hope. People in Italy speak Italian. Download 19.91 Kb. Do'stlaringiz bilan baham: 
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