Text 7c

FURTHER DEVELOPMENT

OF ENGINE-POWERED SHIPS

New types of engines and new sources of power were developed as ships changed from wood to steel and from paddle wheels to propellers. Until the middle to late 1800’s, ships used a one-cylinder steam engine. The steam expanded in the cylinder, drove the piston a full stroke, and then passed to a condenser, where it was converted back to water. By late 1800’s, the compound steam engine, which had two cylinders, began to be used on ships. In the compound engine, steam pushed the piston in one cylinder and then passed on to a second, larger cylinder. The engine thus created much more power from the same amount of steam. The compound steam engine cut the use of coal on ships up to 50 per cent. Later, shipbuilders installed three-, four-, and five-cylinder steam engines on their ships.

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n the 1890’s, Charles A. Parsons, an English engineer, designed a marine steam turbine, a completely new type of marine engine. It was much more powerful and efficient than the steam engine. In 1897, Parsons installed three turbines in his vessel, the Turbinia. The turbines powered the vessel at an amazing 34.5 knots. Within a few years, fast luxury liners began Pic. 24. A Modern Steam Turbine Rotor crossing the Atlantic Ocean powered by steam turbines. One of the most famous of these liners was the British ship Mauretania, launched in 1907. It was 790 ft (241 m) long and had a speed of 27 knots.

While Parsons was working on his steam turbine during the 1890’s, Rudolf Diesel, a German mechanical engineer, was perfecting another new type of engine. It is used heavy oil as fuel. His engine, now called the diesel engine, used less fuel than the turbine and required much less space on a ship. In 1910 and 1911, the first diesel-powered ships, which are called motorships, went into operation. Beginning about 1920, oil also began to replace coal as a fuel for steam turbines. Today, most steamships use oil.

In 1954, the United States launched the world’s first nuclear-powered ship, the submarine Nautilus. It was retired in 1979. In 1959, the US launched the Savannah, the first nuclear-powered merchant ship. It was retired in 1971. Germany, Japan and the Soviet Union also built nuclear-powered merchant ships. But nuclear merchant vessels are still impractical for commercial use because of their high building and operating costs.

Until the late 1940’s, the queens of the seas were the great oceangoing passenger liners. France, Germany and Great Britain built most of these magnificent floating hotels. The liners stressed luxury and service. In addition to the regular deck and engine room hands, an army of cabin and dining room stewards, cooks and bakers, and other service workers staffed the liners.

Beginning in the late 1940’s, airplanes began to carry more and more people across the seas. Today, relatively few passenger liners sail the oceans, and great cargo ships have become the queens of the sea. These ships emphasize efficiency and economy.

Cargo vessels have become bigger, chiefly for economic reasons. For example, shippers have found it far cheaper to transport 100,000 tons of oil in one huge tanker than in five smaller ones carrying 20,000 tons each. Also, for economic reasons, shipbuilders have designed vessels that can be loaded and unloaded in a minimum amount of time with minimum labour.

In addition, ships today have become increasingly automated, so they can be run by smaller crews. On many modern vessels, for example, electronic equipment controls the flow of fuel oil and air to the furnace and of water to the boilers. Automatic navigation aids help keep ships on course. Ships have also become larger and larger, and entirely new types have been developed.

Ex.18. Answer the questions:

1. What are the principles of one-cylinder steam engine operation? 2. What is a compound engine? 3. When was the steam turbine invented? 4. What was the main advantage of steam turbines? 5. What is the difference between motorships and steamships? 6. When and where was the first nuclear-powered ship launched? 7. Why are nuclear merchant vessels still impractical? 8. Why can oceangoing passenger liners be called “floating hotels”? 9. Why have great cargo ships replaced passenger liners as the queens of the sea? 10. What are the reasons of constructing bigger cargo vessels?

Ex. 19. Agree or disagree with the following statements. Give grounds to your answer:

1. A compound steam engine is a device, which has two cylinders. 2. Steam turbines let shipbuilders achieve higher speed and larger size of their ships. 3. The diesel engine is preferable for the ships for economic reasons. 4. Today, steamships still use coal. 5. Nuclear-powered ships are widely spread in the world sea transportation. 6. Passenger liners are staffed like big hotels. 7. As modern ships become bigger and bigger, their crews have increased greatly. 8. Today people prefer airplanes for sea and ocean crossing to the ships.

Ex. 20. Describe the steam turbine, using picture 23 and the information from the text:

Ex. 20. Translate into English:

1. Комбинированный паровой двигатель уменьшал расход угля до 50 процентов. 2. Паровая турбина, спроектированная Чарлзом Парсонсом, была намного мощнее и эффективнее, чем обычный паровой двигатель. 3. Дизельный двигатель потребляет меньше топлива и занимает меньше места на корабле. 4. Первое торговое судно, оснащенное атомным двигателем, было списано в 1971 году. 5. Такие суда непригодны для коммерческого использования из-за высокой стоимости строительства и обслуживания. 6. Океанские пассажирские лайнеры первой половины 20-го века были символом роскоши и первоклассного обслуживания. 7. Намного дешевле перевозить нефть на одном большом танкере, чем на пяти судах меньшего размера. 8. Корабли должны загружаться и разгружаться за минимальный промежуток времени с минимальными затратами труда. 9. Этот полностью новый тип корабля управляется автоматически. 10. Электронное оборудование отвечает за автоматическую подачу топлива, воздуха и воды.

Ex. 21. Abstract the text.

Ex. 22. Speak on the topic “Steam and Motor Ships”