Vocabulary notes:

1. shoal/shallow water – мелководье

2. stroke – ход, такт

3. suction – всасывание

4. particle – частица, комок

5. micrometer – микрометр

6. hiss – посторонний шум, шипение

7. air pocket – воздушная пробка

8. indicator cock – индикаторный кран

9. fuel nozzle – форсунка

10. valve stem – шток клапана

11. discharge valve – выпускной клапан

12. jellyfish – медуза

13. air injection engine – компрессорный двигатель

14. pipe – труба

15. copper – медь

16. devastating – разрушительный

17. public system – коммунальная система водоснабжения

18. joint – место соединения

19. stopcock – кран

20. blowlamp – паяльная лампа

Exercise 2. Read, translate and discuss the text.

Fuel system defects

Derangements in the fuel system are most likely to occur at the fuel measuring pumps. These pumps must handle a very small amount of oil at high pressure on each stroke and in order to do this the suction and discharge valves must be kept in perfect condition. A frequent source of trouble with these valves is dirt or grit in the oil. A small particle of sand or a thread qf waste under a valve will cause it to leak. Good strainers should be provided in the fuel oil supply line to the pumps and the strainers should be cleaned frequently. The pump plungers should be very carefully packed to prevent leakage of oil outward and air inward. Accumulation of air in the pumps will cause either irregular supply of fuel to the engine or stoppage. Stoppage of fuel supply to any one cylinder throws extra load on the other cylinders when the governor acts to increase the pumps discharge. Repeated regrinding of the pump suction valves will require careful checking of the pump timing.

Combustion defects

Normally the combustion in each power cylinder should be smokeless and complete and occur early in the stroke. Insufficient breaking up of the oil during injection will cause slow and incomplete burning and may be the result of clogged fuel nozzles, oil too cold or incorrect timing. Other causes of incomplete burning are compression too low, injection valves not correctly timed and air inlet pipes clogged.

Cooling water system defects

Complete stoppage of the cooling water supply can hardly occur unless the circulating pump breaks down or the ship grounds in shoal water where mud may plug up the sea injection valve, thus stopping the supply of raw water to the coolers of a closed fresh water system or the jacket supply of a sea water cooling system. In the event of the rare occurrence of pump breakage there is always an auxiliary pump available. Most well designed ships, especially when designed to operate in shoal water, have high and low sea suctions. The high suction is used in shallow water where mud might be drawn in through the low suction. The low suction should always be used at sea as the rolling of the ship is likely to throw the high suction out of the water and admit air into the system. It not infrequently happens when ships anchor in tropical harbors that the sea suction becomes clogged with jellyfish. When this happens it can be cleared by blowing out, if a steam or air connection on the body of the sea valve is available.

Failure of the water supply to any individual cylinder or piston may be caused by an air pocket in the supply line to that point or in the upper part of the cylinder head. Where all of the cooling water is passed through the coolers on the air compressor before reaching the engine jackets a leak in a cooler will allow air to blow into the water and stop the supply to all cylinders.

Lubricating system defects

All Diesel engines today are lubricated by the forced feed method and no hand oiling of any part is required. This requires that the engine housings be closed in, to prevent loss of oil through splashing, and the oil piping, with the oil circulating pump, forms a closed circuit through which the same oil circulates repeatedly. Of course the most serious derangement in such a system is loss of pressure.

Air system defects

The most serious derangement that can occur in the air system of an air injection engine, aside from the remote possibility of an explosion, is loss of injection air. Assuming that the compressor suction is open and the bleeder valve in the first stage properly adjusted, a falling off in the air pressure may be due to leaky, broken or stuck compressor valves, an injection valve sticking open, leaky air valve stem packing, leaky joints in the air piping or failure of the cooling water supply. If the air pressure falls to somewhere near the compression pressure in the power cylinders, unless the trouble can be located immediately, the engine should be stopped. If the engine is kept running, there will be a possibility of an explosion inside the injection valve body.

Exercise 3. Answer the following questions.

1) What derangements in the fuel system are most likely to occur?

2) What will cause the valve of the fuel measuring pump to leak?

3) When should combustion occur in each power cylinder?

4) What are the causes of incomplete burning?

5) When can complete stoppage of the cooling water supply occur?

6) What sea suctions do most well-designed ships have?

7) When is the high suction used?

8) Which sea suction is used in shallow water?

9) How are all Diesel engines lubricated today?

10) What is the most serious derangement that can occur in the air system of an air injection engine?

Exercise 4. Translate into English.

1. Неисправности топливной системы чаще всего встречаются в клапанах топливных насосов.

2. Скопление воздуха в насосах либо нарушит регулярную подачу топлива к двигателю, либо совсем прекратит ее.

3. Повторные притирки всасывающих клапанов требуют внимательной проверки.

4. Как правило, сгорание топлива в цилиндре должно быть полным, бездымным.

5. Неполное сгорание может происходить вследствие очень низкой компрессии.

6. Большинство судов, предназначенных для плавания на мелководье, имеют нижние и верхние приемные патрубки забортной воды.

7. При стоянке в тропической гавани приемный патрубок забортной воды может быть забит попаданием в него медузы.

Exercise 5. Make up a dialogue of your own based on the one given below.

A.: What are some of the causes of loss of injection air pressure?

В.: Leaky, broken or stuck compressor valves, injection air valve sticking open, leaky spray air valve stem packing, leaky joints in air piping, loss of cooling water.

A.: How can a start be had if there is no compressor available?

В.: Procure a bottle of CO2 gas and connect it to the starting air line. This gas is non-explosive and safe to use for this purpose.

A.: What are some of the causes of failure of an engine to start firing after it begins to turn on air?

В.: Fuel pumps not discharging oil, incorrect timing of fuel valves, low compression, injection air pressure too low and cylinders too cold.

A.: What are some of the causes of cracked cylinder heads?

В.: Unequal heating, due to poor design, air pockets in jacket, insufficient cooling water and overloading.

A.: How does wear on main bearings cause crank shaft to break?

В.: By throwing the shaft out of line and causing it to be bent in alternate directions twice in every revolution.

A.: Give the valve timing for the average and large 4-cycle engine.

В.: Injection valve opens 5 degrees before top center, injection valve closes 49 degrees past top center, exhaust valve opens 140 degrees past top center, air inlet valve opens 15 degrees before top center, exhaust valve closes 10 degrees past top center, and air inlet closes 214 degrees past top center. When in use, the air starting valve opens at top center and closes at 128 degrees past top center.

A.: What is the most important valve timing?

В.: The time of opening of the injection valve. A small change in this time may seriously affect the operation of the engine.

A.: When setting valves how to determine when the injection valve opens?

В.: Keep moving the cam roller with the fingers until it makes contact hard enough to bind, turn injection air into the valve and listen for the hiss of air through the indicator cock when the valve starts to open, or use a micrometer dial indicator to note when the valve stem starts to lift.

Comprehensive reading. Read, translate into Russian and discuss the following text

Burst of pipes

Burst of pipes in the water system is one of the most common plumbing problems both in the home and the public system. Several things can cause burst pipes, the main one is freezing conditions.

The most likely cause of a burst pipes will come from frozen temperatures and unprotected piping. A pipe bursts when frozen due to the expansion of the water as it becomes ice. This puts pressure on the pipe from the inside and something has to give. This almost always is the soft copper or plastic of the pipe. Sometimes these breaks can be at the weaker joints or in the middle of the pipe. As quite a lot of piping is hidden in flooring, roof spaces or walls, the damage caused can be devastating.

If a pipe freezes...

• Turn off the water supply at the stopcock.

• Check to see if the pipe has burst.

• Slowly thaw the pipe with hot water bottles or a towel soaked in hot water, starting at the end nearest the tap.

• You can also use a hair-dryer (lowest setting) but NOT a naked flame or blowlamp.

Remember: don't leave taps dripping or running as the water may not drain down the plughole if the pipe below is frozen.

If a pipe bursts...

• Turn off the water supply at the stopcock.

• Open all taps to reduce flooding.

• Soak up/block off escaping water with thick towels.

• Call a qualified plumber.

• Turn off taps once pipework is repaired to avoid further flooding.

Exercise 6. Answer the following questions.

1. What is the main cause of burst of pipes?

2. Explain why pipes burst when frozen.

3. What kind of material in pipes can’t stand the pressure?

4. Why is the damage so devastating?

5. What is necessary to do when pipes got frozen or burst?

6. What other advice can you give?

Watch the video “System defects” and discuss the following topics.

[https://www.youtube.com/watch?v=5OeiNpJRFGw]

1) How to prevent or, if it happened, to eliminate cooling water system defects?

2) How to prevent or, if it happened, to eliminate lubricating system defects?

3) How to prevent or, if it happened, to eliminate air system defects?

Lesson 5. STARTING DIFFICULTIES

Exercise 1. Read and learn the following words and expressions.

Synonyms:

1. to refine / to purify / to clarify – очищать

2. thoroughly / fully / completely – полностью

3. probability / likelihood – вероятность

4. moisture / humidity / dampness – влажность

5. hazard / danger – угроза, опасность

6. distinct / definite / plain – явный, определенный

7. rare / uncommon / scarce – редкий

8. impart / relate / disclose – сообщать, передавать