DieselShip's Online Content Library

Q1.a) What are the different types of coupling bolts used in practice? Name at least 3. (3)

b) Explain with the help of sketch, as to how a ‘pilgrim’ hydraulic bolt is fitted and removed? (8)

c) How are fitted boards installed on the coupling? (5)

Q2. i) Sketch and describe the modern purification system using ‘ALCAP’ concept for purifying fuel specific gravity about 0.991. (8)

ii) Explain how ‘ALCAP’ separator operates as clarifier & how is the water drained off? (4)

iii) What is ‘paring disc’? How does it function? (4)

Q3. Clean and dry control air is essential for efficient trouble-free operation of a ship’s pneumatic’ control air system.

a) Sketch and describe a low-pressure control air system used on board ships showing various arrangements to deal with dust oil and moisture as well as safety system. (8)

b) Explain using a line diagram, arrangements provided, to reduce the air pressure to 7/8 bars. Required for control air system. (8)

Q4. a) Whils't on ‘seawatch’ you observe that the Oil Mist detector (OMD) in the engine room has triggered an alarm, and in feeling the crankcase doors on the bottom platform, you find that the unit in question feels warmer than the rest. What pre-emptive action will you take as Watch-keeper to bring the situation under control. (10)

b) Draw a simple line diagram of an ‘OMD’ and explain it’s working. (6)

Q5. i) Define ‘centrifugal pump’ and where it is used on ships? Using a simple line diagram show a circuit which include a centrifugal pump. Explain the meaning of ‘suction lift’. (6)

ii) Sketch and describe the construction of a centrifugal pump, labelling its parts. What is a ‘lantern ring’ and why is it fitted? (10)

Q6. Explain the following terms and give examples of where each condition might occur

a) Stress Corrosion cracking (6)

b) Creep cracking (5)

c) Corrosion fatigue (5)

Q7. a) What are the Safety Devices fitted to an Air Compressor? (4)

b) What is the purpose of the Scum Valve on a Boiler? (4)

c) What is the function of an evaporator in a Refrigeration System? (4)

d) Regarding the Emergency Bilge Injection Valve, what is its relevant size compared to the Main Sea Water Injection Valve? (4)

Q8.a) Sketch a two-ram type hydraulic steering gear with a single Electro-hydraulic pumping unit. Show the hunting gear arrangement and indicate valve positions. (8)

b) State the purpose of, and describe the operation of (8)

i) hydraulic shock/buffer valves.

ii) Oil replenishing tank.

iii) Hunting gear.

Q9.a) Explain why air receivers should be drained frequently and its internal surfaces to be provided with protective coatings (6)

b) Describe the procedure for internal inspection of air receivers and the possible defects that may be encountered. Suggest suitable repair methods for the defects. (6)

c) Describe fault conditions associated with air receiver mountings and the remedies to rectify the same. (4)