DieselShip's Online Content Library

Q1. A very sudden rise in pressure during combustion accompanied by a metallic, hammer like sound is called knocking of the unit or detonation and usually occurs (16)

(a) Near the end of the pressure rise after ignition of fuel charge

(b) Just before the fuel charge is about to ignite

(c) Immediately after the unit reaches peak pressure and before ignition of fuel

(d) At any stage of the combustion process.

State the correct answer and explain why the other reasons given are not justified.

Q2. (a) List and explain the desirable properties of lubricating oil for different application such as for main engine, auxiliary engine and for cylinder lubrication. (8)

(b) Sketch an auxiliary engine lubricating oil circuit. (8)

Q3. With reference to turbochargers:

(a) Explain the term surging, stating how it occurs, its effect on the turbocharger and how it can be avoided (8)

(b) Describe the procedures for cleaning EACH of the following and explain the precautions which should be taken: (8)

(i) Suction air

(ii) Turbine blades and nozzle ring

Q4. Write short notes on:

(a) Control air dryer (4)

(b) Crankcase door (4)

(c) Auxiliary engine overspeed trip (4)

(d) Fuel oil leak off alarm (4)

Q5. A large marine diesel main propulsion engine, speed fluctuates all the time during the voyage. Make written statements to the chief engineer explaining the observation of various engine parameters, during the voyage which could be indication of some fault, causing engine speed fluctuation. (16)

Q6. (a) What are the advantages of a thin shell bearing? (4)

(b) What are the typical bearing failures? Discuss at least four bearing failures. (8)

(c) Why is periodic analysis of the lubricating oil important? (4)

Q7. (a) Why tie-rods are provided on a 2-stroke main engine? (6)

(b) Why tie rods are placed close to the centerline of the crankshaft? (5)

(c) What is a tie rod pinch screw? And what is its purpose? (5)

Q8. (a) Explain briefly how the different moving parts of a main engine are subjected to various stresses. (8)

(b) Name the stresses and justify by stating how they originate. (8)

Q9. Indicator cards have shown that one cylinder is high in power although the maximum pressure is low. State the associated effects that this might have on the various instruments of the engine and give a detailed description of the method of rectifying the defect. If this abnormality were not remedied, what might be the subsequent effects on the operation of the engine? State the type of engine to which your answer refers. (16)

Q1. The main requirements which a fuel injection system must fulfil are (16)

(a) Accurate metering of small amount of fuel oil

(b) Control of quality of fuel injection

(c) Proper timing of the fuel injection

(d) Selective distribution of the fuel in the combustion space

State whether each one of the points made above are true or false with reasons.

Q2. (a) In a 4-Stroke engine, describe each of the four strokes of the engine. (6)

(b) Draw timing diagram of a complete cycle.

(c) How each stroke is completed, in the engine with action of crank travel and valves. (10)

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)

Q4. (a) State the different types of turbo charger fitted in modern diesel engines (8)

(b) Describe the function of the (8)

(i) Nozzle ring

(ii) Labyrinth seals

(iii) Diffuser and

(iv) Inducer

Q5. Sketch and describe a device employed for continuous monitoring of the viscosity of heavy fuel oil being supplied to a main engine (16)

Q6. a) What is the importance of measuring bearing clearance in a diesel engine. (4)

b) What is Bridge gauge? Describe its usage with diagram. (6)

c) What are the other recommended methods used onboard to check bearing clearances. (6)

Q7. a) Describe what is nozzle burning of fuel Injectors and causes of nozzle burning on Marine Diesel engine. (6)

b) What investigations are required to find causes for nozzle burning? (6)

c) What actions are required to reduce the risk of Nozzle Burning? (4)

Q8. Explain how the following conditions affect the power developed by a diesel engine:

(a) Broken piston rings. (4)

(b) Worn fuel pump plungers. (4)

(c) Fouled turbochargers (4)

(d) Worn out liner (4)

Q9. For 2-Stroke Marine Diesel Engine

a) Describe problems in achieving good lubrication of Cylinder Liner. (6)

b) What are the properties of good cylinder oil? (4)

c) What are the consequences of under and over lubrication of liner? (6)