DieselShip's Online Content Library

Q8. a) Draw Lubricating oil piping diagram with all fittings for a trunk type 4- stroke Diesel Engine. (8)

b) What properties are required for a Lubricating oil used in a 4-stroke Diesel Engine? (4)

c) What is the effect on lubricating oil due to various contaminants during operation of engine? (4)

Q3) (a) With a diagram of the lubricating oil line, explain the working of an automatic backflushing filter placed on the lubricating oil line of the main engine. (10)

(b) List the main difference between such filter and a centrifugal separator. (6)

Q4. (a) Describe means of recognizing deterioration of the lubricating oil (8)

(b) Describe how lubrication oil is conveyed to top end, bottom end and main bearings in large bore, 2-stroke cross head type slow speed diesel engine, you are familiar with (8)

Q7. A. State, with reasons, THREE properties required of crankcase oil which is to be used for a trunk piston main engine.

B. Explain how a representative sample of crankcase oil would be obtained from a trunk piston engine. C. Briefly describe the action to be taken if the crankcase oil charge cannot immediately be replaced and analysis shows – (i) Water is present; (ii) Alkalinity has fallen; (iii) Viscosity has changed appreciably; (iv) Carbon content has increased.

Q3. The analysis of oil may be used as a method of monitoring the condition of the equipment that it lubricates A. Explain briefly how shore analysts might test the oil; B. State the type of information that would be expected; C. Give possible reasons for an excess of: - i. Iron, ii. Copper, iii. Antimony Iv. Tin, v. Silica

Q6. Give a reasoned opinion as to the accuracy of the following assertions:

a) Absence of oil grooves in the liner wall between the oil supply points results in increased wear of liner and rings.

b) ‘Timed lubrication’ has little merit,

c) The most suitable position of the oil supply point is immediately below the bottom piston ring with the piston at top dead centre.

Q2. With regard to the main turbine lubrication oil system:

a) (i) Describe the effects of tin oxide corrosion; (5)

(ii) Explain the actions to be taken if this occurs in a high-pressure turbine thrust bearing. (5)

b) Discuss the factors that determine the various filtration sizes: (6)

Q6. Give a reasoned opinion as to the accuracy of the following assertions:

a) Absence of oil grooves in the liner wall between the oil supply points results in increased wear of liner and rings.

b) ‘Timed lubrication’ has little merit,

c) The most suitable position of the oil supply point is immediately below the bottom piston ring with the piston at the top dead centre.

Q3. a) Define the following conditions relating to lubricating oil

(i) Oxidation

(ii) Emulsification

(iii) Acidity

b) Explain how each of the conditions in Q3 (a) is controlled by maintenance

c) Suggest possible consequences if the conditions in Q3 (a) change and no corrective action is taken

Q8. Compare the desirable qualities of the lubricating oil selected for each of the following duties and give reasons for the differing properties of the oils recommended for these three purposes. (16)

a) Auxiliary diesel engines

b) Stern tube bearings

c) Refrigeration compressors

Q2. i) Explain using a simple line diagram difference between lubricating oil systems dealing with cylinder lubrication vis-à-vis crankcase lubrication. (7)

ii) State the properties of oil essential in each of these cases. (4)

iii) What is synthetic oil? How it is different from Mineral oil? Where is it used? (5)

Q2. i) Explain the purpose and applications of using lubricating oils on board. (8)

ii) Name the types of lubricating oil used on ships and mention various properties of same and their significance. (8)