DieselShip's Online Content Library

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. Explain the advantages of fitting highly rated medium speed engines with double exhaust and air inlet valves (6)

(b) State the disadvantages of double valve arrangements (4)

(c) Explain the possible causes of persistent burning of exhaust valves if it is:

(i) General to most cylinders (3)

(ii) Specific to a single cylinder (3)

Q3. Make a report to the Chief Engineer of your vessel about malfunctioning of low lub oil pressure alarm for the auxiliary engine, observed during your watch, with special emphasis on the possible consequences. (16)

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. Discuss the consequences of failure to maintain correct clearances in the case of auxiliary diesel engine crankshaft and bottom end bearing. Describe the procedure of taking crankshaft deflection (16)

Q6. Sketch and describe the operation of a crankcase oil mist detector. What operational maintenance does this instrument require for efficient performance. (16)

Q7. a) With the help of simple diagram, explain Variable Injection Timing (VIT). (8)

b) Explain with suitable diagram, start and end of VIT points. (4)

c) Explain with sketch variation of P(Max) with VIT position. (4)

Q8. (a) What do you understand by Specific Fuel Oil Consumption? Give some examples of SFOC for a two stroke engine and the auxiliary engines. (6)

(b) Explain the terms: (10)

(i) Flash point

(ii) Pour point

(iii) Calorific value

(iv) CCAI value

(v) Octane number and

(vi) Cetane number

Q9. Compare the desirable qualities of the lubricating oil selected for each of the following duties:

a) Auxiliary diesel engines. (4)

b) Stern tube bearings. (4)

c) Refrigeration compressors. (4)

d) Gear case of purifier. (4)

Give reasons for the differing properties of the oils recommended for these four purposes.

Q1. Explain the method of obtaining the following diagrams on a 2-Stroke Main propulsion Engine.

a) Power Card, showing vital point of diagram. (4)

b) Out of phase diagram indicating vital points. (4)

c) Light spring diagram, indicating vital points. (4)

d) Compression diagram and its importance. (4)

Q2. a) With reference to crankshafts and piston crowns outline the main stresses to which these parts are subjected. (4)

b) In each case explain how the stresses are generated and how they very in magnitude and direction during one cycle. (6)

c) With respect to the whole engine, describe how stresses may be accommodated by good design and influenced by poor maintenance. (6)

Q3. a) What is crankshaft misalignment? (4)

b) What are the reasons for crankshaft misalignment? (8)

c) What is the effect on main engine of such misalignment. (4)

Q4. During your watch one of the main engine units was indicating high exhaust temperature reading. Write a note to Chief Engineer explaining.

(a) How the cause leading to abnormal running condition was diagnosed (8)

(b) Subsequent action taken to control the situation (8)

Q5. a) Sketch and describe a fuel oil system of a large diesel engine, from settling tanks to main engine fuel injectors. (10)

b) Also, comment on the importance of

i) Heating arrangement with temperature control. (3)

ii) Prevention of air lock in the system. (3)

Q6. (a) How is a 2-stroke engine started? Describe the sequence of engine starting. (5)

(b) Draw the Timing Diagram of engine starting, showing crank position of each Step. (6)

(c) What is OVERLAP in engine starting? (5)

Q7. With reference to the construction of a turbocharger, sketch and describe

a) The rotor bearing and it's method of lubrication. (6)

b) Labyrinth seal and explain how such a seal work. (6)

c) Impeller and diffuser. (4)

Q8. a) Draw sectional diagram of exhaust valve of 2-stroke Diesel Engine. Name the different components of the valve. (8)

b) Describe working of the valve in operation. How valve rotation occurs during operation and its purpose. (6)

c) What is the special material used on valve lid. (2)

Q9.a) What are the difficulties observed in lubrication of gear teeth in gear trains? (4)

b) Describe with diagram, how good lubrication to gear teeth is achieved? (6)

c) What are the qualities of lubricating oil suitable for main Reduction Gearing of main engine? (6)