ELECTRIC RAILROAD
Electric railroad is an electrically powered railway system. Electrically powered trains include high-speed passenger trains; some freight trains; and the subways, elevated systems, and streetcars found in certain cities. The electricity to run an electric train comes from an external source—a central power plant—rather than from an engine or generator on board the train.
Electric trains have many advantages. They are quieter than other trains and do not produce smoke or exhaust. Coal, gas, oil, nuclear power, or water power can generate electricity for an electric train. In contrast, diesel trains run only on diesel oil. Electric trains also travel faster than any other trains. The world's fastest is France's TGV (train a grande vitesse, or high-speed train). It travels up to about 185 miles (300 kilometers) per hour. Some Japanese electric trains run up to about 160 miles (260 kilometers) per hour. Engineers are developing faster electric trains called maglev (magnetic levitation) trains. German and Japanese models of these trains test from about 250 to 310 miles (400 to 500 kilometers) per hour.
Electric railroads provide intercity service (service between cities). These railroads also offer intra-urban or commuter service, which carries passengers within cities and between cities and their suburbs. Electric railroads are common in many European countries and in Japan. However, in the United States only about 1 per cent, or 2,000 miles (3,200 kilometers), of intercity track is electrified.
Kinds of electric railroads. Most intercity electric trains receive power through an overhead wire called a catenary. In the overhead wire system, a steel framework connects a car, usually a locomotive, to a catenary. The framework, called a pantograph, delivers electric current from the wire to the locomotive's propulsion system. This system includes the traction motors. Traction motors power the driving wheels, which actually move the locomotive.
Intercity electric trains have one or more locomotives that pull freight or passenger cars. Most electric locomotives weigh between 100 and 200 short tons (90 and 180 metric tons) and provide about 6,000 to 7,000 horsepower (4,500 to 5,200 kilowatts). They can reach speeds of over 150 miles (240 kilometers) per hour.
An electrified third rail delivers electricity to most intra-urban electric trains. Trains using a third rail have metal plates called shoes. Two shoes attach to the bottom of a locomotive or railcar. The shoes slide along the third rail, delivering electric current to the car's propulsion system.
Some intra-urban railcars have traction motors, which range from 119 to 282 horsepower (89 to 210 kilowatts). Others are driven by locomotives or by railcars that have traction motors. Intra-urban railcars reach speeds of about 50 to 75 miles (80 to 120 kilometers) per hour.
Unlike most electric trains, a maglev train has little or no contact with a track or wires. Maglev trains have special magnets in the bottom of the cars. The magnets in the cars and electrically charged coils in the guideway (track) create a powerful magnetic force. This force lifts the cars above the guideway. Separate electric currents in the coils create a shifting magnetic field that propels the train forward. Some maglev trains test at high speeds. But only low-speed maglev trains were in use in the early 1990's, serving parts of Europe.
History. In the early 18OO's,the Scottish inventor Robert Davidson built the first full-sized electric locomotive. But the high cost of producing electricity made it too expensive for general use by railroads. The development of the electric generator in the mid-1800's made the modern electric railway possible. This device generated a current of high voltage at low cost.
Exercise 2
Read the following sentences and give English equivalents for the Ukrainian words and words combinations, given in brackets:
1 (Найшвидший у світі потяг) travels up to about 185 miles (300 kilometers) per hour.
2 Electrically powered trains include (супершвидкі пасажирські потяги, деякі вантажні потяги, метро, трамваї).
3 Coal, gas, oil, nuclear power, or water power (можуть генерувати електрику для електричного потяга).
4 (Електричні залізниці) provide intercity service (service between cities).
5 Most intercity electric trains (отримують енергію) through an overhead wire called a catenary.
6 The framework, called a pantograph, (постачає електричний струм) from the wire to the locomotive's propulsion system
7 The shoes slide (уздовж третьої рейки), delivering electric current to the car's propulsion system.
8 (Роздільні електричні струми) in the coils create a shifting magnetic field that propels the train forward. Some maglev trains test at high speeds.
9 Розвиток електрогенератора in the mid-1800's made the modern electric railway possible.
Exercise 3
Now, work in pairs, please. Ask each other questions and answer them. Ask your friend………
1 What advantages electric trains have.
2 What service electric railroads provide.
3 When the development of the electric generator made the modern electric railway possible.
4 Where the electricity to run an electric train comes from.
5 What speed maglev (magnetic levitation) trains can reach.
6 How an overhead wire is called.
7 What trains using a third rail have.
8 What the magnets in the cars and electrically charged coils in the track create.
9 When the Scottish inventor Robert Davidson built the first full-sized electric locomotive.
10 What kinds of trains electrically powered trains include.
Exercise 4
Answer the following questions:
1 What is electric railroad?
2 What do electrically powered trains include?
3 Name the advantages of electric trains.
4 What speed does the world’s fastest France’s TGV develop?
5 What is maglev? Does it have a contact with a track or wires?
6 How do electric railroads work?
7 How many tons do most electric locomotive weigh?
8 What does the term “third rail” mean? How does it work?
9 What speed can intercity electric trains develop?
Exercise 5
Pick out the words from the text having the same roots with the words given below.
Контакт, електрика, система, пасажир, елеватор, центральний, інженер, генератор, продукція, газ, міля, магніт, модель, урбанізація, локомотив, мотор, металевий, пропелер, тестувати, історія, генеральний, вольтметр.
Exercise 6
Match the words from the left column with their antonyms from the right one.
High cheap
External to destroy
Advantage rare
Quiet to give
Fast to stop
Common internal
To receive low
To pull slow
To create noisy
Expensive disadvantage
UNIT 3
Exercise 1
Read the following words and word combinations. Repeat them after teacher. Try to memorize them.
1 internal-combustion engine двигун внутрiшнього згорання
2 spark-ignition іскрове запалення
3compression-ignition запалення від стискування
4 piston поршень
5 cylinder цилiндр
6 to expand розширюватися
7 stroke клапан
8 to receive the pressure отримувати тиск
9 valve клапан
10 flywheel маховик
11 camshaft розподiльний вал
12 crankshaft колiнчастий вал
13 fuel-injection pump паливний насос
14 efficiency ефективнiсть
15 rod шатун
16 supercharging турбонадування
17 to convert перетворювати
18 burn explosively згорати вибухово
Exercise 2
Listen and translate the following sentences in which the new words and word combinations are used.
1 The gasoline engine, found in most cars, is a spark-ignitionengine.
2 The diesel engine is a compression-ignitionengine.
3 Crankshaft and the “main” bearing which support the crankshaft and permit it to rotate.
4 Diesel engines have a high thermal efficiency, or ability to convert the stored chemical energy in the fuel into mechanical energy, or work.
5 Connecting rod is used to transmit force in either direction from the piston to the crankshaft.
6 A cycle begins with the intake stroke when the piston moves down and draws air into the cylinder.
7 The compression ratio necessary to ignite the fuel depends on the size of the engine's cylinders.