DieselShip's Online Content Library

Q6. A. Describe four different methods for reducing Nox emissions from diesel engines; B. Distinguish between primary and secondary methods.

Q7. A. State, with reasons, THREE properties required of crankcase oil which is to be used for a trunk piston main engine.

B. Explain how a representative sample of crankcase oil would be obtained from a trunk piston engine. C. Briefly describe the action to be taken if the crankcase oil charge cannot immediately be replaced and analysis shows – (i) Water is present; (ii) Alkalinity has fallen; (iii) Viscosity has changed appreciably; (iv) Carbon content has increased.

Q6. A. A number of main engine cylinder covers have been subjected to cracking during the preceding four months –

i. Explain possible reasons for this cracking;

ii. State with reasons the action you, as Second Engineer, would take in order to reduce the possibility of future cylinder cover cracking.

B. Cylinder liner wear has increased appreciably during the past six months. Write a brief report to the engineering superintendent concerning this matter explaining the possible causes the immediate action taken to deal with the problem and the action you, as Second Engineer, intend to take in order to reduce the risk of future incidents.

Q9. A.  Difficulty has been experienced in maintaining engine speed at the set value; State THREE possible causes. State how each of these causes may be detected.

B. Describe the action to be taken in order to ensure safe operation of the main engine plant in the event of complete failure of the remote control and sensing equipment.

Q2. Explain with a sketch “speed droop” in a governor; Answer the following

A. How is a main engine governor different from an auxiliary engine governor?

B. Explain how load is transferred to an incoming generator explaining your actions with relation to the governor’s “droop line”.

Q9: A. What are the most influential physical characteristics required of the principle bearings for high speed, medium speed, and slow speed diesel engines? B. Write short notes on following - i. thin bearing shells; ii. Surface finish; iii. Fluid film lubrication; iv. Alignment.

Q7. A. Describe with aid of sketches the following types of bedplates as used for a large I.C. engine - i. Bedplate cast in section; ii. Fabricated steel Bedplate B. State the stresses to which these bedplates are subjected and explain how bedplates are secured to the hull of the ship.

Q8. A. Discuss the principal forces a large diesel engine crankshaft must withstand while in service and how the stresses resulting from these forces are kept within acceptable limits by good design and operation criteria; B. Discuss the manner in which the crankshaft may be overstressed and the consequences arising there from.

Q9. Explain the modern methods of turbo charging available such as A. Pulse converter system; B. Sequential turbo charging; C. Two stage turbo charging; D. Variable geometry turbochargers.