1. the time interval method — система следования поездов с интервалом во времени
2. the space interval method — система следования поездов с интервалом в расстоянии
3.Прочтите текст со словарем и дайте ответы на следующие вопросы. 1. 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?
TEXT A. SAFETY AND HIGH SPEEDS I (1) Today's railways would not be so popular but for the ever-increasing speed. Super-higji speeds, however, go hand in hand with safety. Indeecf^no' passenger would dare to go by rail unless the railways were able to ensure safe travel.
(2) Safety depens 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*"" tenance 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, railwaymen 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 brakesmen.
(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.
