DieselShip's Online Content Library

Q1. An auxiliary engine under load continuously fluctuates even with a steady load. The fault you diagnose could be owing to: (16)

(a) The quality of fuel

(b) The quality of servicing of the governor in the last port

(c) The supply of charge air

(d) The overhaul of fuel injectors done in the last decarbonisation.

Give a brief explanation as to why each of the above mentioned points either could be true or cannot at all be the reasons for such a fluctuation.

Q5. (a) Why exhaust outlet of marine diesel engine turbocharger is lower than inlet temperature? (6)

(b) Why do we need an air cooler and why is the scavenge air temperature maintained at 40°C? (10)

Q3. Discuss the precautions, which can be taken to minimize the possibility of a diesel engine crank case explosion and the transmission of dangerous flame into the machinery space.

(a) By design and equipment (8)

(b) By operating personnel (8)

Q3. (a) Describe means of recognizing deterioration of the lubricating oil (8)

(b) Describe how lubrication oil is conveyed to top end, bottom end and main bearings in large bore, 2-stroke cross head type slow speed diesel engine, you are familiar with (8)

Q6. Write short notes on:

(a) Main air starting valves (4)

(b) Exhaust valve rotator (4)

(c) Scavenge relief valve (4)

(d) Function of Labyrinth Seals in turbocharger (4)

Q6. With reference to medium speed trunk piston engines:

(a) Explain the purpose of an anti-polishing ring (5)

(b) Describe how effective piston cooling is provided (5)

(c) Where is the thrust bearing fitted and why? (6)

Q7. (a) Sketch a section through the bedplate and A frame of a large slow speed engine, identifying parts, method of construction and materials (10)

(b) Explain the function of the tie bolts and how after an alignment problem, these would be tightened (6)

Q8. (a) (i) Describe with the aid of a sketch, a main engine exhaust valve which is hydraulically operated (8)

(ii) Explain the operation of this valve (4)

(b) State the materials used for the seat and valve described in (a) (4)

Q9. Discuss the causes, possible associated hazards and lowering of thermal efficiency consequent on poor combustion in a Diesel engine cylinder. Illustrate your answer by means of indicator cards (16)