The following questions came from candidates right after they had finished their oral exam.



1.        What is tappet clearance? How to take tappet clearance?
2.        What will happen if tappet clearance is less or more?
3.        Explain the procedure of removal of liner in main engine and auxiliary engine.
4.        How to lock the liner at the time of taking out piston from the unit in auxiliary engine?
5.        Explain the procedure of removal of piston in main engine and auxiliary engine.
6.        Explain the procedure of removal of cylinder head of main engine.
7.        How to check AE compression pressure?
8.        How to identify inlet valve and exhaust valve of an AE ?
9.        How inlet valve and exhaust valve lapping is done?
10.    How shall you carry out auxiliary engine cylinder head pressure test?


1.        Why we can’t use single stage air compressor and also explain P-V diagram of it?
2.        Why we use multistage air compressor and what is the importance of it? Why cylinder diameter of compressor decreases after every stage?
3.        What are different trips/ alarm present in air compressor?
4.        What is the location of relief valve, bursting disc and fusible plug?
5.        What is the purpose of unloader valve?
6.        What would be the affect of suction valve having too much lift?
7.        What is the use of intercooler and after cooler in compressor?
8.        How to start air compressors manually on ships?
9.        What is emergency air compressor? Its purpose and regulation?
10.    How do you check compressor efficiency during running?
11.    What are the safeties on air bottle?
12.    What are the mountings on air bottle?
13.    Explain air bottle entry procedure.
14.    What action should be taken in case of corrosion / wasting observed on air bottle?
15.    What would be the affect of suction valve of an air compressor having too much lift?
16.    Air compressor efficiency drops. What may be the reasons?
17.    What are different types of corrosion in air bottle and its effect?


What arrangement is provided on the door which is welded to the air bottle and how to

check whether inside welding is okay or not?



Air compressor is continuously running but air bottle is not filling. What are the possible

causes of it?            

20.    What is the regulation of air bottle as per SOLAS?
21.    What do you understand by the term volumetric efficiency and how clearance volume affect the volumetric efficiency?
22.    What could be the reason of increase in volumetric efficiency? How will you come to know out? How will you adjust it?
23.    What is bumping clearance? How to adjust it? Why do we need it?
24.    What are the effects of valve leaking at various stages (first stage suction, first stage discharge, second stage suction, second stage discharge)?
25.    What are the reasons for fall in compressor performance?
26.    How to maintain air compressor efficiency?
27.    How unloader of deck air compressor work? Explain with drawing.
28.    What is the difference between the air compressor cycle and refrigeration cycle?
29.    What is the procedure of overhauling of compressor valves? Name different parts of compressor valve.
30.    What is the purpose of providing non return valve on the compressor discharge side?
31.    How can you check out low lub oil pressure cut out or high air temperature trip in compressor?
32.    You are on watch and bursting disc of air compressor burst out. What will be your action?
33.    How main bearing of multi stage compressor crankshaft is supported?
34.    How bearing clearances taken in main bearing and gudgeon pin bearing of compressor?
35.    Compressor low pressure relief valve is often lifting. What may be the reasons?
36.    If unloader is not working, how to start air compressor?


1.        What are the internal mountings in boiler? Explain with drawing.
2.        What are external boiler mountings?
3.        Where is vent cock located and its purpose?
4.        What are safety devices in a boiler?
5.        What are the differences between smoke tube and water tube boilers?
6.        Why we need to blow down the gauge glass and what is the procedure of gauge glass blow through? Why we open water side first during blow through?
7.        What are the safeties of gauge glass?
8.        Why we need to blow down the boiler water?
9.        Why do we do scum blow down and water blow down?
10.    What is the procedure of scum blow down and bottom blow down?
11.    What is the procedure of firing boiler from cold?
12.    How shall you prepare your boiler for boiler survey?
13.    What are the tests carried out on boiler water? What is the purpose of it? What is the procedure to carry out various boiler water tests? What is the desired value of various components (compounds) found in boiler water?
14.    What is the purpose of boiler water treatment?
15.    What is foaming in boiler and how to prevent it?
16.    What is boiler priming, reasons of priming and how to prevent it?
17.    What are the reasons of boiler burner blow back?
18.    What action do you take in case of foaming and priming?
19.    What action will you take if boiler gauge glass showing low water level?
20.    What is caustic embrittlement? How to prevent it?
21.    What do we do to prevent excess oxygen in boiler?
22.    What will you do if chloride is found too much in boiler water?
23.    What precautions we should take before turbocharger  washing?
24.    What is meant by accumulation pressure? What is its purpose and what is the procedure to perform accumulation pressure test?
25.    What are different types of ESD boiler?


Draw the diagram of safety valve and the function of different components of safety valve? What is easing gear? How many safety valves are there?
27.    What are different types of safety valve?
28.    Explain the procedure of overhauling of safety valve and what all checks are to be done inside safety valve?
29.    What is the procedure of setting of safety valve onboard?
30.    What is the difference between safety valve and relief valve?
31.    What do you understand by the term shrinkage/swelling of boiler and how to control it?
32.    What is the procedure of hydraulic testing of boiler?
33.    What could be the reason if you are not able to maintain level of water inboiler?
34.    Draw fuel oil circuit diagram for boiler?
35.    What are different types of boiler burner?
36.    How to check whether burner is working fine or not?
37.    Every time you fire the boiler, flame failure alarm comes. What could be the possible reasons for that?
38.    What is economizer fire? Its causes and how to prevent it? What is metal fire and hydrogen fire?
39.    What do you understand by the term water hammering and how to prevent it?
40.    What is steam trap? Explain its working with diagram?
41.    What is spalling?
42.    What is double banking?
43.    How to reduce soot formation in boiler?
44.    There is boiler flame failure alarm. If we bypass it, will it fire?
45.    What is the speciality of boiler water feed check valve?
46.    How do you know boiler is firing properly?
47.    How auto shut down works?
48.    What are the reasons for excess water in steam drum?
49.    What are the types of boiler blow down. Which blow down you shall do first?


1.        Explain the basic principle of purifier and clarifier.
2.        What is the need of purification?
3.        What is gravity disc?
4.        How to choose correct size of gravity disc?
5.        What is the function of paring disc?
6.        What is the difference between purifier and clarifier?
7.        How do you change purifier to clarifier?
8.        What are the causes of excessive vibration on purifier?
9.        What are the possible reasons of purifier overflowing?
10.    How to adjust bowl height?
11.    Why multi disc are provided?
12.    Why we need water sealing in purifier?
13.    How does the bowl closes by bowl closing water although it is too heavy?
14.    How to manually start the purifier and checks done before starting and stopping of the purifier?
15.    Explain the principle of working of ALCAP?
16.    What is the reason of providing the clutch in purifier and why it is not directly coupled?
17.    If the electrical officer interchanges the motor connection of purifier, what will happen?
18.    What is wobbling and how to check it in purifier and where?
19.    What things will you check in purifier gear case inspection? 
20.    Why friction pad is used in purifier? 
21.    How will you measure vertical shaft height?
22.    Draw purifier clutch working with diagram.
23.     What is the use of friction pad in purifier?
24.    Why purifier vertical shaft arrangement has two bearings at bottom?
25.    What is the effect of reduced purifier bowl height?
26.    Why we don’t use gravity disc in clarifier?
27.    Where we find spring in purifier?


1.        Explain the general vapour compression cycle for refrigeration system.
2.        What are the desired properties of a refrigerant ? What is oil differential pressure cutout?
3.        What are the safeties in refrigeration system?
4.        What are the different methods of charging refrigerant in the system?
5.        What is critical temperature?
6.        What is primary refrigerant?
7.        What is secondary refrigerant?
8.        What is the principle of refrigeration? Name some refrigerants used onboard.
9.        What is solenoid valve? Its function? Why it is fitted?
10.    What is the function of thermostatic expansion valve? What maintenance are to be done on TEV?
11.    What do you understand by the term internal equalizing and external equalizing?
12.    What are tests to detect leakage of refrigerant in the system?
13.    What is refrigeration and air conditioning?
14.    What is the purpose of ventilation of cargo hold?
15.    What is short cycling of refrigeration compressor?
16.    Why superheat is required at evaporator outlet?
17.    What could be the reason of HP cut out in the refrigeration system?
18.    What are the causes of:

  • Compressor starting and stopping immediately.
  • Compressor is running continuously.
  • Unusual sound from compressor.
  • High compressor discharge temperature.
  • Evaporator coil icing.
  • Reduced cooling capacity.
  • Reducing oil level in compressor.
19.    How will you get to know out air in the system and how to remove it?
20.    What is the function of backpressure valve in refrigeration system and why it is fitted inside vegetable room only?
21.    How unloader works in refrigeration system?
22.    Why compound gauge fitted in refrigeration system?
23.    Icing on evaporator coil. What are the possible reasons?
24.    Why refer compressor is generally belt driven?
25.    How will you come to know if there is air in the refer system. And how to remove it?
26.    How to check if refer belts are slack or tight?
27.    How will you check performance of unloader?
28.    If unloader valve of your air compressor not working, what action shall you take?
29.    Why crankcase relief door not fitted in refrigeration compressor crankcase?
30.    Why a heater is provided in refer compressor crankcase?


1.   What are different types of fresh water generator and explain the working of fresh water generator that you have onboard?
2.        What could be the reason for loss of vacuum in FWG?
3.        Why scale formation is not the major concern in FWG as compared to boiler?
4.        What could be the reason of high salinity in FWG?
5.        Explain the procedure of starting the FWG?
6.        Explain the procedure of stopping the FWG.
7.        How to regulate the capacity of FWG?
8.        How scale formation takes place in FWG and how to minimize it?
9.        At what sea water temperature, water production will be more? 10 degrees or 25 degrees. Explain.                                         
10.    Fresh water discharge capacity decreases. Reasons?
11.    Fresh water salinity alarm comes. What may be the reasons?
12.    How do you test a FWG plant for leak?


1.        How steam trap works?
2.        Draw the diagram of hydraulic jack and how it works?
3.        What surface preparation you shall do before welding?
4.        What are non destructive tests? Explain them.
5.        Draw the diagram of retainer ring or circlip.
6.        What are different types of welding process?
7.        Name and explain some welding defects.
8.        What precautions should be taken during welding?
9.        How accommodation is welded to hull? Name the type of welding.
10.    What is heat treatment? What are different heat treatment methods?
11.    What is annealing and brazing?
12.    How to order a bolt?
13.    What are types of washer?
14.    What checks are carried out in spring?
15.    How  to detect surface cracks?
16.    How to prevent crack from propagating?
17.    Explain different types of threads.
18.    Explain stud ordering procedure.
19.    How to check the strength of bolt?
20.    What are the safeties on Auxiliary Engine?
21.    Why vacuum condenser and atmospheric condenser is needed?
22.    Define enthalpy and entropy.
23.    What are the reasons for dry docking?
24.    What inspections we make during dry docking?
25.    What is rudder drop? How to check rudder drop and what instrument do we use to check it?
26.    What is propeller drop? How to check propeller drop and what instrument do we use to check it?
27.    What is poker gauge, trammel gauge and bridge gauge?
28.    What is ICCP? Which is anode and cathode in it? What is the difference between sacrificial anode cathodic protection method and ICCP?
29.    What is fitted bolt?
30.    What are different types of washers?
31.    How will you measure whether piston burnt out or not?
32.    Draw and explain profile gauge.
33.    Your sea water pipe near main cooler has to be replaced. How shall you order the pipe?
34.    What is cascade tank and what inspections you will carry out in it?
35.    What are destructive tests? Explain.
36.    How shall you detect leak in AE L.O cooler?
37.    What is dowel pin and its uses?
38.    What are different arrangements for emergency generator starting?
39.    How shall you test JCW for its suitability or further use?
40.    What is the procedure of bunker line pressure testing?
41.    Explain the procedure of AE decarb?
42.    Name the parts of lathe machine. What jobs can be performed on lathe machine?
43.    What are advantages and disadvantages of 3 jaw chuck and 4 jaw chuck?
44.    What are different types of thread and its application?
45.    What are steering gear room safeties?
46.    What are the reasons for error between the helm order & angle shown locally on steering gear unit?
47.    What are emergencies in steering gear system?
48.    What is sluggish movement of rudder?
49.    What is hunting of rudder?
50.    What is the function of buffer spring?
51.    Explain hunting gear mechanism.
52.    What are the safeties in steering gear system?
53.    What is steering gear regulation as per SOLAS?
54.    What is safematic system in steering gear?
55.    What is follow  up and non follow up system?
56.    What are the causes of air entering into steering gear hydraulic system? How to remove air from system?
57.    Explain radial piston or hele saw pump.
58.    Explain the working of axial piston pump or swash plate pump.
59.    What are the safeties on windlass?
60.    What are steering motor safeties?
61.    What is shaft earthing device?
62.    Explain different types of taps with drawing.
63.    What is hot working and cold working?
64.    What are the safeties on milling machine?
65.    How shall you take over a watch?
66.    How shall you prepare main engine for departure from port?
67.    What is meant by M18 bolt?
68.    Draw the diagram of mechanical seal?
69.    What is emergency bilge suction? How to test its working?
70.    What are safeties on engine room crane?
71.    What maintenance we should carry out on engine room crane?
72.    How to detect leak in shell and tube type heat exchanger?
73.    How to perform survey of plate type cooler?
74.    Explain different types of corrosion.
75.    What is MGPS system?
76.    What expansion arrangement is given in shell and tube type heat exchanger for the expansion of tubes.
77.    What are oxygen scavengers?
78.    What is steam jetting?
79.    What checks we carry out on chain block?
80.    What is ERMATO JOINT?
81.    How to stop aux engine if not stopping by stop handle?
82.    What is go gauge?
83.    Why emergency bilge suction is bell mouthed?
84.    What are safeties on tanker?
85.    Hydrophore cut in and cut out frequently? What may be the reasons?
86.    How to calibrate inside micrometer?
87.    How to order grinding wheel?
88.    What are the safeties on oxy acetylene cylinder?
89.    While using how we keep acetylene bottle?
90.    Which type of sewage treatment plant is used onboard on your ship? How vacuum is created? What may be the reasons for vacuum not creating?
91.    Explain oily water separator (OWS) working in full detail. What all mountings are there on it and why placed in OWS?
92.    Which tap you will use in 10 mm plate?
93.    What does M8 bolt mean?
94.    What are different types of fit ? Explain with example types of fit used in engine room.
95.    How to  pressure test a heat exchanger?
96.    How to calculate vernier scale least count?
97.    How to advance fuel pump timing of a particular unit?
98.    How to put threads on wooden plate?
99.    Sea water pipe line onboard your ship developed hole. How to rectify? State permanent and temporary solutions.
100.How will you fabricate new pipe having S-shape in workshop and welding procedure on the same pipe.
101.What is the function of pintle bearing?
102.How vibration is produced in engine? What is first order and second order moment?
103. When we use static balancing and dynamic balancing?
104.Explain plate type heat exchanger overhaul procedure.
105. What shock absorbing provision is present in rotary vane steering gear?
106.What maintenance you do on AE 1000 hrs routine?
107. Draw phase change curve for heat treatment process.
108. What is the difference between hypo and hyper eutectic steel?
109.What affect does change in carbon% bring in the nature of a compound?
110.How to find leak in heat exchanger?
111.What is bolt extractor? How it works?
112.Name all lathe parts and their function.
113.Type of steam trap in cargo heating line?
114. What is Fitting bolts and where to use?
115.What maintenance we carry out on scrubber tower?


1.        What are different types of pump and their uses?
2.        What is NPSH?
3.        Draw the diagram of internal and external gear pump.
4.        What is the principle on which centrifugal pump works?
5.        What is the function of wear ring and casing ring?
6.        Explain the working of centrifugal pump  with graph.
7.        What check we need to perform before starting centrifugal pump?
8.        Centrifugal pump trips on overload. Reasons?
9.        Why centrifugal pump is called roto dynamic pump?
10.   Draw the characteristic curve of centrifugal pump for series and parallel operation.
11.Why reciprocating pump is called positive displacement pump?
12.    What do you understand by the term cavitation & briefly tell causes of cavitation.
13.    Explain centrifugal pump starting procedure.
14.    Why centrifugal pump can’t handle air?
15.    What is squat phenomenon?
16.    How wear ring is fitted on impeller?
17.    Why centrifugal pump is not self priming?
18.    What are the causes of centrifugal pump reduced output.
19.    What are the reasons for vibration in centrifugal pump?
20.    What is the purpose of inducer?
21.    What is the purpose of mechanical seal?
22.    How to check clearance between wear ring and casing ring?
23.    What is the purpose of lantern ring?
24.    How to cut the gland packing?
25.    What are the disadvantages of gland packing?
26.    Pump is not taking suction. How to know?
27.    What is the function of water ring ?
28.    What are cargo pump room safeties?
29.    Complete procedure of overhauling of centrifugal pump?
30.    How to check different alignment in centrifugal pump?
31.    Which pump is used as bilge pump and why?
32.    What is single acting and double acting reciprocating pump?
33.    What is role of air vessel at the outlet of reciprocating pump?
34.    Pump is not able to take suction from aft bilge well. Reasons?
35.   Explain the basic principle of gear pump and importance of backlash.
36.   Explain the basic principle of screw pump and importance of timing gear in it.
37.    Explain axial displacement pump.
38.    Explain hele shaw pump.
39.    Explain the procedure of gear pump overhaul and checks made after overhaul.
40.    Why we are using double volute casing now a days?
41.    How to fit wear ring on impeller and casing?


1.        Explain the procedure of gate valve overhauling.
2.        What is the procedure of bilge well valve and SDNR overhaul?
3.        Explain the procedure of globe valve overhauling.
4.        If seat of valve have big groove what will you do?
5.        What is the difference between  SDR valve and SDNR valve?
6.        How lapping of sea water valve and compressor valve? How tocheck correct lapping?                       
7.        How will you check that valves are leaking?


1.   Reasons of smoky exhaust?
2.        ME one unit exhaust temperature rise. Reasons?
3.        Engine speed drop. Reasons?
4.        ME one unit exhaust temp drops. Reasons?
5.        Charge air pressure drops. Reasons?
6.        Jacket water pressure fluctuates. Reasons?
7.        Jacket water temp increases. Reasons?
8.        Engine fails to start on fuel. Reasons?
9.        Running gear hot. Reasons?
10.     Engine turns on air, but not on fuel. Reasons?
11.    Engine doesn’t fire. Reasons?
12.    Piston running hot. Indications and action?
13.    Cracked cylinder head. Causes and indications?
14.    Individual piston knocking at TDC. Causes?
15.    Bearing temperature increases. Reasons?
16.    You give the kick but engine fails to come on air. What might be the reasons?
17.    Lub oil temperature is abnormally high. What will be your action?
18.     What will be your action when lub oil level is increased in sump?
19.    What will be your action when lub oil level is decreased in sump?
20.    ME all units exhaust temperatures are going high. What may be the reasons?
21.    Refrigeration compressor is short cycling frequently. List the possible reasons.
22.    Scavenge air temp of one unit goes high. What may be the reasons?
23.    AE cooler fouled? What are the possible reasons?
24.    Generator surges at low load. Reasons?
25.    What action you take in case stern tube starts leaking?
26.    What are the reasons of black smoke from diesel engine?
27.    What are the reasons for error between helm order and angle shown locally on the steering gear unit?

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Manish Mayank

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