Section 9  pantograph and current collection

RAILWAY POWER SUPPLY

 

1) propel ^- приводить в движение, продвигать; propulsion – движущая сила

2) power supply - энергоснабжение;

3) traction (diesel, electric) - тяга (дизельная, электрическая);

4) steam locomotives (engines) - паровые локомотивы;

5) efficient - эффективный;

6) power station (plant) - электростанция;

7) produce electric current - производить электрический ток;

8) tractive effort (power) - тяговая сила;

9) air pollutant - загрязнение атмосферы; air pollutant - загрязняющий агент;

10) prime mover - источник энергии;

11) turbotrain - турбопоезд;

12) gas-turbine engine - газотурбинный двигатель;

13) power car - вагон энергоснабжения;

14) horse power (hp, HP) - лошадиная сила; мощность.

 

Ex. 1.. Answer the following questions:

1) What types of engines may trains be propelled by? 2) How do you think, what types of locomotives - steam, diesel or electric - may be used for heavy mainline service? 3) What type of tractive power did the first locomotives run on? 4) What type of locomotive is more expensive to build - diesel or electric? 5) Have you heard of trains propelled by gas-turbine engines? Give your examples, if any.

 

Ex. 2.. Read and translate the text using the words from exercise 1.

RAILWAY POWER SUPPLY.

Trains may be propelled by various types of engines: diesel, electric or aircraft ones. Hence, railway power supply is based on diesel or electric traction.

First locomotives were steam ones, they played an enormous part in acceptance railways as the dominant means of inland transport in the last century. Without it we might not have our present national networks of railways. However, nowadays steam locomotives are on their way out in many counties. The reason is that, first of all, diesel and electric locomotives which taking place of the former steam engines, are available for work over much longer periods, can maintain a higher average speed and are less costly. In fact, steam engines were never efficient in turning coal into energy - only about 7 per cent of the available heat was used (the same coal could be better used in a power station to produce electric current to drive an electric locomotive.

 

Diesels or Electrics?

 

The diesel and electric locomotives have some common features. As well as the electrics (electric locomotives), the diesels(diesel locomotives) are always ready for service because the diesel engine can be started within a minute or two in any weather and can be in operation for perhaps a week without visiting a depot. As well as the electrics, the diesels are capable of developing a high tractive effort at low speeds and, therefore,can start and accelerate heavy trains. These features allow the diesel locos to be used for heavy mainline service.

  On the other hand, the diesel locomotive is more expensive to build and maintain than the electric of equal power since the diesel locomotive carries a power plant on itself. In addition, the diesel engine is an air pollutant prime mover, so the diesel traction should not be recommended for use on suburban lines round large cities. Noise and vibration are also considered the drawbacks of the diesel locomotive. Another disadvantage of the diesel locomotive is that the diesel engine runs on organic fuel the supplies of which are not inexhaustible. Diesel traction is normally employed today on non-electrified trunk lines and on lines where traffic is not dense enough to justify electrification.

The history of railway traction is abundant in types of energy used for starting trains. In the second half of the 20^th century aerospace engineers designed turbotrains the operation of which was based on the technology of flight. The new American turbotrain had an aircraft-type gas-turbine engine and developed a speed of 157 miles/h on standard jointed rail tracks. In France turbotrains began running between Paris and Cherbourg in 1971. Each power car of the train carrying a pair of gas turbines contained a driver’s cab which had been specially designed to give the maximum driving efficiency and control. On Paris-Lyon route gas-turbine locomotives developed a maximum speed of 300 km/h. British Advanced Passenger Train (APT) consisted of two aerodynamically-styled power cars each fitted with four 300-h.p.

 

 Ex. 3. a) Make a list of advantages of diesel locomotives. Use the text to help you:

1 can start heavy trains

2 _________________

3 _________________

4 _________________

b) Make a list of disadvantages of diesel locomotives. Use the text to help you:

1 expensive

2 ___________

3 ___________

4 ___________

c) Now name all the common features of diesels and electrics. What are the advantages of electrics?

  Scan the text and say what type of traction it deals with.

 

Natural Gas Railcar Debut

German Rail (DB) is claiming a world first, by operating passenger trains powered by natural gas which is said to produce very few harmful emissions compared with a diesel-powered train. The project has aroused such interest that DB and French National Railways (SNCF) now plan to develop a new natural gas lightweight railcar.

Two 30 to 40 year old two-axle lightweight diesel railcars belonging to DB's subsidiary and operating on the Baltic island of Usedom were converted to natural gas propulsion. The conversion involved the replacement of the diesel engine on each railcar with an Otto engine with spark plugs which can be powered by compressed natural gas.

An advantage of natural gas is that the railcars can travel about 750 km more on a full tank than they could when they were diesel powered.

The environmentally-friendly propulsion concept fulfilled all the expectations during trials in the foothills of the Alps. Measurements showed that emissions of nitric oxide were cut by about 97 %. Carbon monoxide by 84 % and hydrocarbons by about 70%. Another advantage of natural gas over diesel is that there is no soot emission from the exhaust pipe. The natural gas engines are also quieter than their diesel counter - parts.

The German and foreign rail vehicle industry has taken notice of this propulsion technology, and is considering whether to develop and offer new generation lightweight railcars with natural gas propulsion", said Mr Roland Heinisch, DB's board member for research, technology and traction.

 

 

EXERCISES

 

Ex. 4.  Translate the attributive groups:

high speed electric train — high speed electric train power — high speed electric train power equipment — high speed electric train power equipment development; good contact maintenance problem — good contact maintenance problem discussion; control system minituarisation conference.

 

Ex. 5.  Translate the sentences paying attention to the word «since»:

1.    Since the advent (появление) of power electronics a lot of mechanical movements required during high speed train operation have been eliminated (устранять).

2.    Since relays (реле) now are replaced by electronic control, the train control systems have become very small in size.

3.    Since the new line has been electrified with AC power at industrial frequency the new trains can start running on it.

4.    Since we often use the word «tramway» we should know its origin (происхождение). In 1800 Benjamin Ostram decided to support the street rails on stone instead of timber. Since then, this type of road became known, first, as «ostram roads», later as «tram roads» from which was derived modern «tramway».

 

Ex. 6. Translate the sentences paying attention to the Infinitives:

1.    It is planned to make a new extension (участок) from the Isle of Dogs, under the River Thames, to Greenwich.

2.    The whole metro system will have a new signalling system to be operated at 2 minute headways (интервалы).

3.    Today powerful computers are used to monitor the driverless trains in Great Britain.

4.          To lose power supply to the train, it is necessary to lower the pan.

5.          A lightweight transverse frame is used to support the contact strips.

 

 

Ex. 7. Read and translate the international words:

pantograph, isolation, contact, cylinder, pressure, maintain, maintenance, support, cause, original, compress, acceleration, detection, formation.

 

Ex. 8.  Pay attention to the translation of the words «the more..., the better...»:

a) the less..., the higher...; the longer..., the heavier...; the sooner..., the better...; the smaller..., the less expensive...; the bigger..., the more powerful...;

b) the higher the speed, the more difficult...; the longer the line, the more substations....

 

Ex. 9.         Translate the sentences paying attention to modal verbs:

1. This old line is to be connected from diesel to electric traction next year.

2. A new line will have to be electrified by the end of the year.

3. As electric locos can accelerate more rapidly, more trains can runon the same track.

4. As there were some defects in the train power supply system, the train had to be removed from service.

5.This train was to be back in service after examination and repair.

 

Ex. 10.  PANTOGRAPH AND CURRENT COLLECTION

Current is collected from overhead lines by pantographs. Pantographs are easy in operation. You must lower the pan to lose the power supply to the train. However, they provide some complications.

Since the pantograph is usually the single point power contact for the locomotive or power car, it must maintain good contact under all running conditions. The higher the speed, the more difficult is the maintenance of good contact, because a pantograph moving at a high speed may cause the formation of a wave in the wire.

Pantograph contact is maintained either by spring or air pressure. Com-pressed air pressure is preferred for high speed operation. The pantograph is connected to a piston in a cylinder and air pressure in the cylinder maintains the pantograph in the raised condition.

Originally, pantographs were «diamond-shaped pantographs» with the contact head at the top. There are two contact faces normally. More modern systems use a single arm pantograph —just half of the original shape which is a neater looking design.

The contact strips of the pantograph are supported by a lightweight transverse frame which has «horns» at each end. These are turned downwards to reduce the risk of the pantograph being hooked over the top of the contact wire as the train moves along. This is one of the most common causes of wires «being down». A train moving at speed with its pantograph hooked over the wire can bring down several kilometres of line before it is detected and the train stopped.

 

Ex. 11.      Read the text without a dictionary:

 

THE FIRST DIESEL-ELECTRIC LOCOMOTIVE IN RUSSIA

November 6, 1924 is considered to be the birthday of the first main line diesel-electric locomotive in the world. On that day, a powerful die-sel-electric locomotive built to the design of professor Gakkel was put into operation on the Russian railways.

The designer of this locomotive, J.M.Gakkel (1871-1945), was born in Irkutsk, to the family of a military engineer. After graduating from the Petersburg Institute of Electrical Engineering, he worked as an engineer in a number of Russian cities such as Perm, Kiev and St. Petersburg. A man of profound engineering knowledge and creative power he made a considerable contribution to the development of Russian science and en­gineering. He designed some original types of aeroplanes, which won him recognition and popularity with aircraft designers; he made a lot of inven­tions in the field of locomotive and tram-car construction. In 1920 he be­gan the most important work of his life, that of designing a diesel-electric locomotive.