Bedplates

Most bedplate troubles arise from the surprising flexibility of what is usually a massive structure of cast iron. An example of this was the bed of a 500-hp. engine that had been carefully reset to correct an original misalignment. After accurate align­ment was complete and the bed was resting on permanent steel chocks, the spaces between chocks were closed with wooden filler pieces, as is the usual custom in marine work. It was found that a too thick filler piece driven under the bed at about its center with an ordinary hand hammer bowed up the bed enough to throw the coupling on the end of the crank shaft measurably out of line. This flexibility seldom results in any injury to the bed itself, but often has a serious effect on other parts of the engine structure, particularly the crank shaft.

Framing

Frames are subject to the same sort of deflection as the bed, and in many cases this deflection is caused by the bending of the bed.

Cylinders

Cylinders, or what may more precisely be termed cylinder jackets, give very little trouble, although on some of the older engines an occasional cracked cylinder will be found. Cylinder liners, however, are a prolific source of work for the repair yard. Liner casualties occur either from wear or cracks. Wear is a nor­mal result of engine use, but it sometimes assumes abnormal pro­portions if operating conditions are not right. Of course, the liner material has some bearing on rate of wear in service and there is some variation in the quality of liner iron found in different makes of engines, but there is not enough variation to make this an important factor in differences in length of liner life found in service. What appears to be the most important factor is the fuel used. Some fuel will contain more abrasive impurities than others, but it is believed that all fuel oil, even the highest commercial grades, should be passed through a centrifuge before being used in the engine.

Exercise 1. Answer the following questions.

1) What does the good condition of the engine depend upon?

2) What repairs can be done at sea?

3) Why are repairs at sea restricted to a certain amount of insig­nificant items?

4) What does the conscientious engineer take pride in?

5) What are the conditions under which maintaining the ma­chinery becomes difficult?

6) Where is a large proportion of motor-ship repairs done?

7) What do most bedplate troubles arise from?

8) Why should all fuel oil be passed through a centrifuge?

9) Why are frames subject to the same sort of deflection as the bed?

10) What appears to be the most important factor in the length of liner life?

11) How does the quality of liner iron influence the length of liner life?

Exercise 2. Give the Russian equivalents of the following.

1) Operating efficiency.

2) Recourse to outside help.

3) Routine examination.

4) Maintenance repair.

Exercise 3. Use the correct words from the text.

1) The ship has been refloated without ... to outside help.

2) He was a conscientious worker and always took ... in main­taining his engine in good condition.

3) Under such . . . repairs at sea became impossible.

4) The repairs required the engine to be disabled but within the short time . . . for such work it could not be done.

5) The bedplate had to be reset to correct the original . . .

6) The cylinder liners of this engine give much . . . and are a pro­lific source of work for the repairmen.

Exercise 4. Translate into English.

1) Многие экипажи гордятся тем, что могут длительное время эксплуатировать силовую установку своего судна без ре­монта.

2) Однако существуют условия, при которых становится невоз­можным обойтись без посторонней помощи.

3) Часть ремонтных работ выполняется непосредственно на су­доремонтном заводе.

4) Многие ремонтные работы, требующие вывода из строя ма­шины, не могут быть выполнены в море.

5) Ремонт двигателя практически ограничивается теми работа­ми, которые можно выполнить в море.

6) Рубашки цилиндров в современных двигателях доставляют много хлопот.

7) Если условия эксплуатации двигателя неправильные, износ некоторых деталей превышает нормальные допуски.

8) Качество используемого топлива является важным фактором в эксплуатации двигателя.

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