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Q3: Your ship after having been accidentally grounded was taken to a dry-dock for inspection and necessary repairs. What defects would you look for in the following parts, that may have sustained damage due to grounding and suggest methods of repairs and tests that may be required to be carried out to the defects noticed:

A. Propeller and tail end shaft.

B. Main engine crankshaft.

Q2. a) During an inspection it is noticed that tie rods of certain main engine units have become slack, state with reasons the possible causes of this.

b) Explain how correct tension is restored and the risk of future slackness minimized.

c) A tie rod has fractured and cannot be replaced immediately, State with reasons the course of action to be adopted in order to allow the engine to be operated without further damage.

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. With respect to hydraulic Ram steering gears;

A. What emergency locking device can be used in order to speedily bring the steering gear to rest? State one reason the best angular position to lock the steering gear.

B. Use a simple sketch to show where the “Jumping” (top) and wear down (bottom) rudder carrier ring clearances can be measured. Indicate what clearances you would expect with a new steering gear;

C. State the consequences of the wear down clearances being reduced to less than Zero.

Q2.  Describe TWO methods of tracing a superficial crack in a marine machinery component; Explain the procedure for arresting propagation of a crack in a machinery component.

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.

Q7. An Auxiliary boiler is periodically unattended and equipped with alarms to cover low water level, high steam pressure, and air and flame failure.

A. State why and how fuel the burners are automatically cut off under alarm conditions of water level, steam pressure, air and flame failure.

B. Describe how and when each of the above alarms is tested without endangering the boiler.

Q8. Sketch and describe a turbocharger-bearing lubrication system. State the type of bearing employed and explain the advantages and disadvantages of the lubricating system described.

Q9. a) State the reason for fitting crosshead guides to engines and explain why ‘ahead’ and ‘astern’ faces are required with uni-directional engines.

b) Describe how crosshead guide clearance is checked and adjusted.

c) List reasons for limiting such crosshead clearance.