post I have given the list of the questions that were asked in oral examinations
of 4B. In this post I have picked some of the famous questions that were asked
in the marine engineering oral exams. Answer to these will be published
shortly. If you have any suggestions, please drop a reply below.
Oral question bank for class IV examinations
FUNCTION 1: Marine Engineering
2. What is the allowed chloride content?
3. Why is the boiler water circulating pump required for EGB?
4. How does a bourbon pressure gauge work?
5. How do you blow through a boiler gauge glass?
6. Why is a ball given in the gauge glass?
7. How do you tighten a gauge glass after assembly?
8. What is the setting of a boiler safety valve?
9. What is the normally allowed chloride content in a water tube
10. How do you blow down a boiler and inspect it?
11. Why is pre purging necessary before firing boilers?
12. How does flame failure alarm come?
13. Type of boiler burner on last ship
14. What is the voltage used for the igniter?
15. How will you know EGB is leaking?
17. What is the purpose of soot blowing?
18. When do you start the circulating pump?
19. What is the temperature of steam in the boiler?
20. What is meant by superheated steam?
21. How is a boiler safety valve set?
22. What is the setting?
23. What is the meaning of accumulation of pressure test?
24. How do you blow down a boiler and inspect?
25. How do you repair leaks?
26. How do you blow through gauge glasses?
27. What is the safety mechanism in case the glass breaks?
28. Which part of a ship’s boiler has a higher safety valve
29. When is the pressure testing of boilers done? How is it done?
30. Why is Fridge compressor belt driven?
31. What is meant by 1 ton of refrigeration?
32. Is there any difference in lub oil pressure readings of
compressors when compared to air compressors?
33. How do you read the lub oil pressure of fridge compressors?
34. Some times the pressure gauges used in fridge systems also
temperature readings. What is the use of this?
35. How is the temperature of cold room maintained ?
36. What is the role of the TEV?
37. What is mean effective pressure of diesel engine?
38. What is the cooling water treatment
39. What tests are done on L.O.?
40. What is the correct procedure for L.O. sample collection?
41. Exhaust temp of one unit is high; what could be the reason?
42. How is LO for X head lubrication delivered in (B&W/
43. Why is a bursting disc provided in air compressors?
44. Where is it provided?
45. If a bursting disk ruptures, what will be your action?
46. What are the safeties fitted on air compressors?
47. If the interstage relief valve is lifting, what could be the
48. Why is multistage compression used?
49. How will you test the working of a compressor safety valve?
50. How does the Oil mist detector work?
51. How will you test the opening pressure of a crank case relief
52. How many tie rods will be there? Function of tie rods?
53. What is a lantern ring?
54. What is the role of the Thrust block ?
55. Where is the thrust bearing in MC series or RTA engines?
56. Why is the thrust bearing at the aft end of the engine and
not at the
57. Why is the thrust bearing close to the engine and not close
58. What is the allowed O2 content in IG? How is it controlled?
59. M/E stuffing box components?
60. What is the role of the stuffing box?
61. What is the difference between stuffing box drain oil and
space drain oil?
62. Why are piston rings changed?
63. What is the difference between a PV breaker and PV valve?
What are the
64. Why is deck seal used in IG systems?
65. What are the COPT trips?
66. What is the starting procedure for COPT?
67. 4 stroke Valve timing diagram
68. What are the strokes in 2 stroke and four stroke engines
69. Difference between purifier and clarifier
70. What is the separation principle used in purifiers?
71. What is the relation between oil density and gravity disc
72. Why are telescopic pipes used for oil lubrication?
73. Why is Fuel timing important?
74. How is checked and adjusted? (engine type based on
75. What is the principle of a diesel engine?
76. Why are 2 springs sometimes used in inlet and exhaust valves?
77. What will you check in springs during o’haul?
78. How does a roto cap work?
79. How is BHP calculation using indicator diagram done?
80. What is MEP and MIP?
80. What is MEP and MIP?
81. What is the difference between the two?
82. Why is cylinder head fitted in engines
83. Are there engines w/o cylhead?
84. Draw 2s timing diagram
85. Why is an expansion tk provided in jcw system?
86. Why do we Blow through’ Engines?
87. How is T/C RPM measured?
88. Is there any difference between A/E and M/E Governors
89. Indicator cards why and how are they taken?
90. What is Hydrodynamic lubrication?
91. What is a rolling contact bearing?
92. What is MCR and CSR?
93. What is PS? What is its relation to kW?
94. What was the specific fuel consumption in your last ship?
95. What was the specific Cyl oil consumption?
96. What is the relation between power and rpm of a main diesel
97. What will be the power developed by a main engine if it runs
98. What is the relation between the ship’s speed and engine
99. Will the engine develop any power, if it is run when a ship
100. What is a CPP? How does it function?
101. What is the difference between fuel valve opening pressure
102. What is an under slung crankshaft?
103. How many crankshafts are there in Vee type engines?
104. How are connecting rods fitted?
105. Do two stroke engines need tappet clearance adjustment?
106. How will you know, without opening anything, that an engine
is 2S or
107. What are the two strokes in 2S engines called?
108. Why does Sulzer use hydraulic jack bolts for main bearings?
109. What is the meaning of TBN in lub oils?
110. Why is LO of different TBN used for M/E cyl oil and
111. What are the values of TBN for A/E crankcase oil?
112. What is the difference between “heat” and
113. If water is found in crank case lo, what could be the cause?