EKM-Jul-2021 (1)

Q1. 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.

Q2. During a routine crankcase inspection the main engine top end bearing is found to be wiped and subsequent inspection shows that the pin is badly scored. A. Explain in detail the action which should be taken to enable the engine to be safely operated so that the vessel may reach a port where effective repair facilities are available. B. State with reasons the factors which influence the speed at which the engine may be safely operated.

Q3. A set of indicator diagrams including drawcards has been taken for the main diesel engine. Examine critically the following if the compression curve is normal i. The maximum pressure is lower ; ii. The maximum pressure is higher ; iii. The expansion curve is lower; iv. The expansion curve is higher; B. Describe how the faults as mentioned above can be rectified

Q4. (a) Sketch a unit for automatic monitoring and regulation of the fuel viscosity. (b) Describe fuel change over procedures that are followed for switching from distillate fuel to heavy residual oil and vice versa.

Q5. Explain the term “cascade control’ and sketch such a system suitable for use with a main engine jacket cooling water system. Show the variation of pressure and temperature at major points of the system.

Q6. A number of main engine exhaust valves have suffered cracking and corrosion at the seating faces since you joined the ship as a second engineer. Write a report to the superintendent covering the following points: i. Reasons which made the problem evident. ii. Your actions to address the problem. iii. Analysis of the possible causes. iv. Recommendation of preventive actions to avoid recurrence.

Q7. A. Sketch and describe the Main engine starting air distributor. 

B. List the safety devices and interlocks incorporated in the main engine air starting system and state the purpose of each.

Q8. With reference to medium speed engine cylinder liners: A. Explain the cause and effects of Polishing or glazing; B. Describe, with the aid of sketches, an anti-polishing ring; C. Explain the action of the anti-polishing ring during the operation of the engine.

Q9. a). If an auxiliary diesel generator over-speeds and runs away while off the load, explain: - i. How it can be stopped, ii. What is likely to be the reasons for the failure. b). Give details of what checks are made after the machine has been stopped: (i) Mechanically, (ii) Electrically.