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Q1. With Respect to a turbocharged 2-Stoke Main Propulsion Diesel Engine:

a. What is the purpose of Auxiliary Blower.

b. What are the safeties provided for the scavenge air receiver.

c. Why do we require scavenge air cooler?

Q2. With reference to the burning of heavy residual fuel in the main engine:

a) State with reasons FOUR modifications which need to be made as compared with the same engine burning distillate fuels. (8)

b) State with reasons SIX properties you would require seeing in the specification for residual fuel indicating the effect EACH of these properties might have with respect to the storage and burning of the fuel. (8)

Q3. (a) Explain why variable exhaust valve closing can be advantageous in the operation of large slow speed main engines. (6)

(b) Explain, with the aid of a sketch, how variable exhaust valve closing is achieved. (6)

(c) Explain how high impact is avoided as the valve closes. (4)

Q4. a) Enumerate the causes of vibration in diesel machinery and shafting. (5)

b) Describe procedures by which it may be reduced by operating personnel, suitable design and devices. (6)

c) State the possible effects of vibration on machinery and crewmembers. (5)

Q5. a) Describe how propeller shaft/stern bearing clearance is measured. (4)

b) Identify with reasons the major factors which substantially determine the range of permissible clearance. (4)

c) State with reasons what parts of propeller shafts should receive particularly close inspection upon withdrawal of such shafts for survey. (4)

d) State why some propeller shafts require less frequent inspection than others. (4)

Q6. Sketch and show all parts of a two-stroke engine stuffing box. Describe the procedure of overhauling two stroke engine stuffing box, without removing piston. All safety precautions and proper tools used for overhaul to be mentioned. (16)

Q7.a) What is the purpose of the main thrust bearing? (4)

b) When checking the main thrust bearing, what dimensional checks would be necessary? (4)

c) How is a thrust bearing cooled? (4)

d) Describe, with a sketch, the special chocking arrangements normal to thrust bearing. (4)

Q8. With reference to an engine air starting system

(a) Explain why a slow turning is fitted. (4)

(b) State, with reasons, when a slow turning system operates. (6)

(c) Describe, with the aid of a sketch, an air starting system, explaining how the slow turning system operates. (6)

Q9. a. Explain why top bracing is used for large crosshead engines. (4)

b. Describe, with the aid of a sketch, a hydraulic top bracing unit for a large crosshead engine indicating where the top bracing is fitted and how it operates. (6)

c. Write instructions for the checking of a large crosshead engine top bracing system and a holding down system. (6)