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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.

Q2. Periodical Lubricating Oil Analysis, its correct interpretation and corrective measures are of critical significance for the maintenance of marine machineries. With reference to the modern analysis techniques employed for the condition of L.O, discuss the following:

A) Elemental (Spectrometric) Analysis

B) Fourier Transform Infrared (FTIR) Spectroscopy

C) Particle Count

D) Base Number Vs Acid Number

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)