DieselShip's Online Content Library

Q1. With reference to the protection of electric motors explain EACH of the following:

(a) Fuse back up protection (6)

(b) How a motor fitted with fuse back up protection may exceed its rated temperature without being tripped by the primary protection (6)

(c) The value of current rating at which the over current relay should be set (4)

Q1. (a) Explain the types of turbocharging in a marine diesel engine. (8)

(b) What are the reasons that may induce vibration on a main engine turbocharger? (8)

Q1. (a) Describe how leak in a Heat exchanger tube is detected? How to rectify leaky tube? (8)

(b) What are the common methods to enhance heat transfer of heat exchanger? (4)

(c) Describe reasons for poor performance of heat exchanger and actions to rectify the same. (4)

Q1. a) What do you understand by the term ‘EEXI’? Provide an overview and its implementation process. (8)

b) Discuss the improvement methods commonly considered in order to achieve energy efficiency optimization with respect to EEXI? (12)

Q1. With reference to control system state, explain in brief:-

a) Two step action. (6)

b) Proportional control. (5)

c) Offset. (5)

Q2. Explain how sluggish action of the suction and delivery valves reduces the volumetric efficiency of an air compressor. (16)

Q7. a) State the conditions, which must be satisfied before an A.C generator can be paralleled with live bus-bars. (4)

b) Sketch a lamp-bright configuration for synchronizing lamps. (8)

c) State the advantages and disadvantages of the lamps-bright system over lamps-darks system. (4)

Q2. Describe the Stern Tube Lubrication System by drawing a schematic diagram and explaining function of each component. (16)

Q8) a) Sketch a line diagram showing a typical “Inert Gas System used for inerting the cargo tanks of oil tankers, labelling the components parts. (6)

b) Describe the system. (8)

c) State what oxygen content you would expect in the flue gases if good combustion achieved (2)

Q3. With respect to the properties of fuel oil, explain the significance of the following terms.

(a) Calculated Carbon Aromaticity Index (CCAI). (4)

(b) The importance of Sodium to Vanadium Ratio. (4)

(c) Sulphur content. (4)

(d) Pour point. (4)

Q3. (a) Sketch, the circuit diagram of an instrument used for measuring electrical insulation resistance. (8)

(b) Describe the circuit diagram sketched in (a), explaining how it operates when measuring electrical insulation resistance. (8)

Q3. a) Explain why bunkering is considered a hazardous operation? What type of casualty can occur during bunkering? Discuss the implications of such incidents, if so happens. (10)

b) Name the bunkering procedure to be followed.

i) in preparation of receiving bunkers. (4)

ii) while receiving bunkers. (3)

iii) on completion of bunkering. (3)

Q3. (a) Why Engineering Materials are tested prior manufacturing of their components. (6)

(b) Describe the various destructive and non-destructive tests carried out on materials for shipboard used. Explain the purpose of each test and where the same applied. (10)

Q4. (a) What causes cavitation in a Centrifugal pump operation? (6)
(b) If the Engine room Bilge pump not taking suction, explore the probable reasons? (6)
(c) Why is a centrifugal pump started with its discharge valve shut? (4)

Q1. a) Explain the working principle of an alkaline battery. (8)

b) Compare the alkaline battery with Lead-Acid battery. (8)

Q4. a) What are the Sulphur limits for fuel in use under MARPOL? (5)

b) What happens if compliant fuel cannot be obtained in the port of bunkering? (5)

c) What if the Sulphur analysis resulting from a commercial analysis does not match the bunker delivery note? (5)

d) What are the timelines for installation of “in use” fuel sampling points on ships? Does it apply for existing ships? (5)

Q4. With reference to a typical shipboard refrigeration system:

a) Sketch the arrangement which controls superheat temperature of refrigerant gas leaving the evaporator. (8)

b) Describe the operation of the arrangement sketched in (a) assuming one of the HFC refrigerants is the working medium. (4)

c) Explain the purpose of the equalizing connection. (4)

Q5. (a) How will you align a motor-pump shaft? What are the different methods of alignment that can be used? (8)
(b) Why is the Fridge compressor belt Driven? (8)

Q5. Write short notes on the following:

(a) EPIRB and SART (5)

(b) Hydrostatic Release Unit (HRU) (5)

(c) Pyrotechnics (5)

(d) Muster list indicating essential elements (5)

Q5. The maritime decarbonization is a priority and there are various ships that are operating on alternative fuels. Discuss few potential alternate fuels by comparing their properties and list the advantages & disadvantages of at least three alternative fuel? (16)

Q4. a) What is the purpose of AVR in an alternator? (6)

b) With the aid of a simple circuit diagram explain the basic working of a brushless alternator. (10)

Q5. With regard to keeping the gas side of boilers in good condition,

Discuss EACH of the following.

1. The mechanism of combustion, stating the factors which are important to good combustion (6)

2. Oil fuel treatment (5)

3. Soot removal equipment (5)

Q6. (a) Explain why a purifier is not attaining its rated speed on starting from rest? (8)
(b) How do you select the appropriate Gravity Disc of Purifier? Why is this selection an important element in the purifier operation?

Q6. Write short notes on:

(a) Main air starting valves (4)

(b) Exhaust valve rotator (4)

(c) Scavenge relief valve (4)

(d) Function of Labyrinth Seals in turbocharger (4)

Q6. (a) What is the metric length of one shackle of an anchor chain? (4)

(b) A vessel of 10000 t displacement burns 25 t of fuel per day when her speed is 12 knots. Calculate the probable consumption of fuel over a voyage of 3000 nautical miles at a speed of 11 knots with a displacement of 11000t. (12)

Q7. In the following circuit, E1 = 13 V, E2 = 19.5 V, R1 = 5 W, R2 = 7 W, R3 = 9 W. Find the current flowing through each resistor. (16)

Q6. (a) State the causes of scavenge fire in a two-stroke engine and explain how the possibility of such an occurrence can be reduced. (10)

(b) If a scavenge fire does occur what action should be taken? Discuss the use of CO2 and dry powder for extinguishing such a fire and describe a fixed installation for applying one of these substances. (10)

Q6. Explain why regular testing of water in auxiliary boilers is desirable. For each, test normally carried out, state,

a) Reasons for making the test (6)

b) Acceptable values for any particular type of auxiliary boiler (5)

c) Action required when measured values differ appreciably from desired values. (5)

Q7. (a) What are the reasons for foaming in refrigeration compressor crankcase? (4)
(b) Describe the causes for the following in the domestic refrigeration system: (3*4)
(i) Frequent cut-in and cut-out of the compressor.
(ii) Lub oil low pressure cut-out of the compressor.
(iii) High pressure cut-out of the compressor.
(iv) Frosting in the compressor suction side.

Q7. Make a diagrammatic sketch of a jacket cooling water system as applied to a two stroke main engine. Indicate the temperatures and pressures in the system. Describe in particular the flow of water from entry to the engine to outlet from the engine and sketch the more important joints in the system. (16)

Q7. A 24V emergency battery is to be charged from the 110V ship's mains when the e.m.f. per cell has fallen to a minimum value of 1.8V. The battery consists of 12 cells in series, has a capacity of 100 Ahr at a 10 hr rate and the internal resistance is 0.03Ω/cell. If charging continues until the voltage per cell rises to 2.2V, find the value of the variable resistor needed to control the charging. The charging current can be assumed to be equal to the maximum allowable discharge current (16)

Q7. a) What are the requirements of Emergency Source of electrical power as per SOLAS Convention as amended, in cargo ships? (6)

b) Name the services that are required to be supplied power from emergency source. (6)

c) What are the starting arrangements for emergency generating sets? (8)

Q7. With reference to electric arc welding:

a) Draw a labeled sectional sketch of a satisfactory butt weld. (5)

b) Briefly define the following defects that may occur and how they may have been caused (6)

i) Under cut

ii) Splatter

iii) Inclusion

iv) Blow hole

v) Incomplete root penetration

vi) Lack of fusion

c) Why is alternating current generally more popular then direct current for metal arc welding? (5)

Q8) (a) Describe the effects of taking fresh water from the shore as feedwater for auxiliary boilers. (5)

(b) Describe the measures taken to reduce these effects. (5)

(c) What is the purpose of deaerator in the boiler feed water system? How is the deaeration achieved? (6)

Q8. How would you test the preparedness of your ship in anticipation of a Port State Control (PSC) inspection, before arrival port in the following areas:

(a) Paint store and galley (4)

(b) Fire control station and CO₂ room (4)

(c) Steering gear including chemical locker (4)

(d) Lifeboat deck (8)

Q8. Write short notes on the following:

(a) Indicated Power (3)

(b) Specific fuel oil consumption (3)

(c) Brake power (3)

(d) Mechanical efficiency (3)

(e) Thermal efficiency (4)

Q9. A wooden ring having a mean diameter of 200 mm and a cross-sectional area of 400 mm2 is wound uniformly with a coil of 300 turns. If the current passed through the coil is 5 A calculate the value of flux produced in the coil. (16)

Q8. Compare the desirable qualities of the lubricating oil selected for each of the following duties and give reasons for the differing properties of the oils recommended for these three purposes. (16)

a) Auxiliary diesel engines

b) Stern tube bearings

c) Refrigeration compressors

Q9. Write Short notes on the following:

(a) Effect of worn out rings on oil consumption and blow past (5)

(b) Cylinder liner wears (6)

(c) Thermal loading of piston (5)

Q6. A coil of resistance 10 ohm and inductance 0.1H is connected in series with a capacitor of capacitance 150pF, across a 200 V, 50 Hz supply.

Calculate:

a) the inductive reactance. (3)

b) the capacitive reactance. (3)

c) the circuit impedance. (2)

d) the circuit current. (2)

e) the circuit power factor. (2)

f) the voltage drop across the coil. (2)

g) the voltage drop across the capacitor. (2)

Q9. Describe the following turbocharger cleaning operations.

(a) Turbine side water washing. (6)

(b) Turbine side Dry Cleaning. (5)

(c) Blower side water washing (5)

Q9. Reverse osmosis is the contemporary alternative for shipboard production of drinking

a) Describe using simple diagrams where necessary, the principle of:-

i) Osmosis (3)

ii) Reverse osmosis (3)

b) Sketch a line diagram showing a ‘single pass system’ for producing fresh from seawater. (4)

i) Describe such a system. (4)

ii) State the safety features that may be incorporated into the plant. (2)