Методические указания для студентов 1 курса заочного обучения (стр. 8 из 9)
The electrical equipment controls the starting of the engine, its ignition system, and the lighting of the car. It consists of the battery, a generator for charging it when the engine is running, a starter and the necessary wiring. Electricity also operates various automatic devices and accessories, including windscreen wipers, directional signals, heating and air conditioning, cigarette lighters, powered windows and audio equipment.
Lubrication
In the force-feed system, a pump forces the oil to the main crankshaft bearings and then through drilled holes in the crankpins. In the full-force system, oil is also forced to the connecting rod and then out to the walls of the cylinder at the piston pin.
Cooling
At the moment of explosion, the temperature within the cylinder is much higher than the melting point of cast iron. Since the explosions take place as often as 2,000 times per minute in each cylinder, the cylinder would soon become so hot that the piston, through expansion, would «freeze» in the cylinder. The cylinders are therefore provided with jackets, through which water is rapidly circulated by a small pump driven by a gear on the crankshaft or camshaft. During cold weather, the water is generally mixed with a suitable antifreeze, such as alcohol, wood alcohol, or ethylene glycol.
To keep the water from boiling away, a radiator forms part of the engine-cooling system. Radiators vary in shape and style. They all have the same function, however, of allowing the water to pass through tubing with a large area, the outer
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surface of which can be cooled by the atmosphere. In air cooling of engine cylinders, various means are used to give the heat an outlet and carry it off by a forced draught of air.Text 19: "THE HISTORY OF LAND TRANSPORT"
Introduction
The word transport means to carry people or goods from place to place. It is also used for the vehicles that carry people or goods - for example, motor transport includes buses, lorries, motor coaches and motor cars. The American word for the same thing is transportation, and the remark "transportation is civilization" was made by an American, the motor-car manufacturer Henry Ford.
The history of transport is divided into two stages. The first stage is that in which all forms of transport depended directly on the power of men or animals or on natural forces such as winds and current, The second stage began with the development of the steam engine, which was followed by the electric motor and the internal combustion engine as the main sources of power for transport.
Porters and Pack Animals
The most ancient people were probably wanderers. They did not live in settled homes because they did not know how to till the soil. As they moved from place to place they had to carry their goods themselves. The porters were usually the women, probably because the men had to be ready to beat off attacks by wild beasts or enemies. Even now, to carry the household goods is the job of women in backward wandering tribes.
The next step was the use of pack animals for carrying goods. The kind of animal used varied in different places, but the general idea was the same - the bundles or baskets were carried by the animals on their backs. The dog, although too small to carry much, was probably one of the first transport animals used because it is so easily trained. Dogs are still to be trained for dragging sledges in the Arctic because of their light weight.
The next advance in land transport came with the invention of the wheel. The wheel at once led to the development of two-wheeled carts and four-wheeled waggons and carriages, but before these could be used for carrying goods over long distances, a system of roads was necessary. These roads had to be wide enough to take a cart and paved, for unless their surface was paved the wheels sank in and the cart stuck. In Britain, and also over much Europe, the first long-distance paved roads were made by the Romans, chiefly so that troops could be marched without
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delay from place to place. The roads made it possible to use wheeled traffic. However, when the Roman Empire collapsed, the roads gradually got into a very bad state.
There were two problems to be solved - first, how to make good roads, and, second, to decide who was to pay for them. In Great Britain these problems were solved in the 18th century. Stretches of roads were handed over to groups called trusts. The trusts borrowed money for repairing and improving the roads, paying it back from the sums they collected from road users. This method of paying for new roads and bridges is still used, especially in the United States.
Then it became possible to travel rather comfortably by coaches. In cities like London, rich people had their own carriages, while poor people went on horseback or walked. Then appeared carriages that could be hired for short distances. They correspond to the modern taxis. The word is short for taxi cab which in turn comes from the words taximeter and cabriolet. A cabriolet is a light two-wheeled carriage introduced from France in the 19th century. The taximeter is a mechanical device connected with the wheels which, by measuring the distance traveled, shows the fare due at any moment. It is also controlled by a clock so that waiting time too is charged for.
Text 20: "THE WHEEL, STEAM CARRIAGES AND RAILWAYS"
One of mankind's earliest and greatest inventions was the wheel. Without it there could be no industry, little transportation or communication, only crude farming, no electric power.
Nobody knows when the wheel was invented. There is no trace of the wheel during the Stone Age, and it was not known to the American Indians until the White Man came. In the Old World it came into use during the Bronze Age, when horses and oxen were used as work animals. At first all wheels were solid discs.
The problem to be solved was to make the wheels lighter and at the same time keep them strong. At first holes were made in the wheels, and they became somewhat lighter. Then wheels with spokes were made. Finally, the wheel was covered with iron and then with rubber.
Light two-wheeled carriages were used widely in the ancient world. As time passed they were made lighter, stronger, and better. Later people joined together a pair of two-wheeled carts into a four-wheeled vehicle. At first only kings and queens had the privilege of driving in them.
In the West the first steam carriage was invented in France. The three-wheeled machine had the front wheel driven by a two-cylinder steam engine, and carried two people along the road at a walking pace. It was not a great success, as the
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boiler did not produce enough steam for keeping the carriage going for more than about 15 minutes.The steam engine appeared in 1763. It was followed by several improved steam road carriages. Their further development was prevented by railway companies. The rapid spread of railways in the United Kingdom was due largely to George Stephenson, who was an enthusiast as well as a brilliant engineer.
He demonstrated a locomotive that could run eighteen kilometres an hour and carry passengers cheaper than horses carried them. Eleven years later Stephenson was operating a railway between Stockton and Darlington. The steam locomotive was a success.
In Russia the tsar's government showed little interest in railway transportation. After long debates the government, which did not believe in its own engineers, finally decided to invite foreign engineers to submit (представить) projects for building railways in Russia.
Yet at the very time when foreign engineers were submitting their plans, in the Urals a steam locomotive was actually in use. It had been invented and built by the Cherepanovs, father and son, both skilful mechanics and serfs (крепостные). The first Russian locomotive was, of course, a "baby" compared with the locomotives of today. Under the boiler (котел) there were two cylinders which turned the locomotive's two driving wheels (there were four wheels in all). At the front there was a smoke stack (труба), while at the back there was a platform for the driver.
Text 21: "WATER TRANSPORT"
One of the most important things about water transport is the small effort needed to move floating craft. A heavy boat or a barge weighing several tons can be moved through the water, slowly but steadily, by one man. An aeroplane of the same weight as the barge needs engines of 1,000 horsepower or more in order to
fly.
The raft made of logs of wood is supposed to be the earliest type of boat.
Rafts seem to be clumsy vessels, although the Norwegian scientist Thor Heyerdahl and his five companions in 1947 made a voyage on the raft Kon-Tiki from Peru to Tuamotu Islands - a distance of 4,500 miles.
The water transport in ancient times developed most rapidly on great rivers. The ancient Romans used vessels to carry their armies and supplies to colonies. These ships, usually called galleys, continued to be used in the Mediterranean till 1750.
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The introduction of the magnetic compass allowed long voyages to be made with much greater safety. At the end of the 15th century, sailing vessels are known to have carried men from Europe to America and round Africa to India.
The middle of the 19th century proved to be the highest point in the development of sailing ships.
Steam and Motor Ships. One of the earliest steamboats is known to have been tested at the end of the 18th century. The first steamship to cross the Atlantic was the Savannah, 98-foot ship built in New York, which made the crossing in 1819. Like all the early steamships, it had sails as well as paddles.' By the middle of the 19th century it became possible to build much larger ships for iron and steel began to replace timber.
The rapid increase in the size and power of ships was promoted by the industrial revolution. The industrial countries produced great quantities of goods which were carried to all parts of the world by ships. On their return voyages, the ships brought either raw materials such as cotton, metals, timber for the factories, or grain and foodstuffs for the growing population.
During the same period, a great deal was done to improve ports, and that permitted larger ships to use them and to make loading and unloading faster.
Improvements introduced in the 20th century included the smoother and more efficient type of engines called steam turbines and the use of oil fuel instead of coal. Between 1910 and 1920 the diesel engine began to be introduced in ships. These diesel-engined ships are called motor ships.г The largest ships, however, are still generally driven by steam turbines. In the late 1950s a few ships were being built which were equipped with nuclear reactors for producing steam. In 1957 the world's first atomic ice-breaker was launched in Leningrad. This atomic ice-breaker is equipped with an atomic engine owing to which her operating on negligible quantities of nuclear fuel is possible. In spite of the capacity of her engine being 44,000 h.p. it will need only a few grams of atomic fuel a week.
The atomic ice-breaker has three nuclear reactors. The operation of the nuclear reactor is accompanied by powerful radiation. Therefore, the icebreaker is equipped with reliable means of protection. The ice-breaker is designed for operation in Arctic waters.
Canal Transport. Sea-going ships can use some rivers, such as the Thames in England, the Rhine, and the Volga in Europe and the Mississippi in the United States. Generally, however, a river has to be "canalized" before ships can use it. This means widening and deepening the channel and protecting its banks so that they do not wash away and block the river with mud.
We find the British canals to be quite narrow and shallow.
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The canals in Europe are much larger than those in Great Britain. France has a big network of canals, centred on Paris, and linking ports of the Atlantic, Mediterranean and English Channel3 coasts with each other and with other countries.NOTES TO THE TEXT
1 paddle - гребное колесо
2 motor ship - теплоход
3 the English Channel - Ла-Манш
Text 22: "INTERESTING FACTS ABOUT CANALS"
The best examples of canals used for draining land are found in Holland, where much of the country is below sea-level. Dams are used to prevent flooding and since 1932 over 300,000 acres of land have been drained. In winter the Dutch people use the frozen canals for ice-skating.
In a hot dry country such as Egypt water is scarce, and to prevent the land from becoming dry long canals are built from dams. These canals must be continually kept open, for the Egyptian farms and cotton fields cannot exist without these life lines of water.
Many inland waterways are used for the transport of heavy goods by barges. This method of carrying materials is not so widely used now, for although it is cheaper, it has the disadvantage of being much slower. Speed is regulated by the number of bridges and locks1 which the barges encounter.
Two notable canals for ships in Europe are the Corinth Canal and the Kiel Canal. The former was built in 1893 across the solid rocks of the isthmus2 of Corinth. Bridges from the tops of the steep sides of the canal connect north and south Greece. The Kiel Canal, which also has no locks, was built two years later and it gives the countries of the Baltic Sea quicker access to the west.
Venice, at the Adriatic Sea, is one of the most beautiful cities in Europe, for it has many canals instead of streets. Long narrow boats with curved ends, called "gondolas", carry passengers and goods from one part of the city to another. The gondolas are supplied with lanterns, which at night make the canals very colourful and romantic. A peculiar custom of former days was that the Ruler of Venice used to throw a ring into the water each year to show that the city was wed3 to the sea. One of the greatest arteries of world trade is the Suez Canal separating the two continents of Asia and Africa. As trade with India increased, the overland route across Suez became regular but very expensive. In 1859, the French engineer, Ferdinand de Lesseps, started to cut a passage through this flat desert country. Ten years later, the first seagoing ships passed through the canal, which is a hundred
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miles long and has no locks, thus completing a direct water route from the North Atlantic to the Indian Ocean.
The journey along the canal takes about fifteen hours and shortens the distance from Britain to the East by about 4,000 miles. The canal belongs to Egypt and is a vital waterway serving the merchants fleets of many nations.
The Great Lakes which lie between Canada and the United States have become part of the world's ocean highways for it is now possible for big ships to sail up the Saint Lawrence Canal to the ports of Toronto, Cleveland and Chicago. A 218 mile canal joins the Atlantic with these Great Lakes which contain half of all the fresh water in the world. There are seven locks, five on the Canadian side and two on the United States side. Bridges needed to be raised fifty feet to allow big ship traffic to pass and, indeed, from Montreal, these ocean-going vessels are raised 246 feet above the sea-level to Lake Ontario. The Saint Lawrence Canal takes the ships 2,200 miles inland, half-way across the North American continent and deep into the heart of Canada.
NOTES TO THE TEXT
1 lock - шлюз
2 isthmus - перешеек
3 to be wed - быть обрученным
Text 23: "AIR TRANSPORT»