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Q3. With reference to radial lip seals for propulsion shafting :

(a)  Describe, with the aid of a sketch, an outboard seal arrangement as fitted to an oil lubricated stern tube;

(b)  Explain, with reasons, the possible actions that should be taken in the event of loss of oil from the header tank.

Q2.a) Describe the design and construction features of a bed plate of a large marine engine, including the materials used and why they are selected for this application. (8)

b) Discuss the importance of the bed plate in ensuring the proper alignment and support of the engine components. Include in your answer how it handles the loads and stresses during engine operation. (8)

Q3.a) Explain the key parameters tested during the laboratory analysis of marine fuel oil and their impact on engine operation if they are not in range. (8)

b) What remedial measures should be taken if the fuel oil parameters are found to be out of acceptable range? Discuss the potential actions for issues like high water content, excessive sulphur, low flashpoint, Acid number and Ash content. (8)

Q8. A. Sketch, and describe, a valve suitable for reducing air pressure and maintaining the reduced pressure within close limits. B. Describe the processes through which air from the starting air receivers should be treated before it is used in a pneumatic control system.

Q4. With reference to hydraulic steering gears, sketch and describe each of the following: (A)Single failure concept;

(B)100 Percent redundancy.

Q6. a) Describe, with the aid of a sketch, an external system for reducing engine NOx emission, explaining the chemistry of the process. (8)

b) Explain why Urea is used in the selective catalytic reduction process instead of ammonia. (4)

(c) Explain why the exhaust gas quality must be monitored before and after the selective catalytic reduction unit, stating how such monitoring influences operation of the SCR unit. (4)

Q8. (a) Sketch diagrammatically an auxiliary boiler automatic combustion control system and explain how it operates.

(b) Specify how ‘fail-safe’ conditions are ensured.

(c) How, the master controller follows steam pressure variations and air fuel ratio is adjusted?

Q3. With reference to propeller shaft alignment:

a) state the objectives of a satisfactory alignment

b) state the conditions that must be met to achieve satisfactory alignment

c) explain what is meant by fair curve alignment.

d)Define "sag and gap" in shaft alignment calculation.

Q2. a) Define creep and specify the conditions under which it occurs?

b) Discuss three metallurgical processing techniques that are employed to enhance the creep resistance of metal alloys