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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.

Q1. 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

Q3. State, with reasons, THREE properties required for a cylinder lubricant for a main engine operating on HFO.

(b) Describe, with the aid of a sketches, an electronically controlled cylinder lubrication system, stating how the timing and quantity of cylinder lubricant is regulated and set.

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)

Q9. (i) Discuss 'on board testing' of lubricating oil. What are the salient points for which lube oil testing is necessary? (4)

(ii) Name the test which are normally carried out and reasons for same. (4)

(iii) Name instruments used for measuring ‘viscosity' and 'flash point' Explain their, working principle (8)

Q4. With reference to lubricating oil:

(a) Explain why oil employed in the crankcase of a trunk piston engine differs in its properties from that employed in the crankcase of a crosshead engine. (6)

(b) List FOUR effects of bacterial attack on crankcase oil.

(c) Explain the action which must be taken if bacterial attack of the crankcase oil is detected. (4)