DieselShip's Online Content Library

Q5. With reference to arresting the headway of vessels of considerable mass, give reasoned opinions on EACH of the following statements: A.  Full power availability for astern running of the propeller is inconsequential; B. Results have been disappointing in those instances where rudders have been adapted to act as retarders; C. Discreet use of transverse thrust units may reduce stopping distance.

Q1. A. Describe the preparation necessary before the application (in dry dock) of sophisticated or approved long life coating to the underwater surface of the hull;

B. State the significance of the roughness profile.

C. List the different sophisticated costing which are available.

Q1. A. Sketch and describe a pneumatic control system for controlling temperature of main engine lubricating oil at outlet of the cooler and; B. Explain why air supplied to a pneumatic control system must be free from dust and water; C. Describe how above impurities are removed; D. State the possible consequences if the air supply is contaminated.

Q3. A. Explain why it is necessary to have reverse power protection for alternators intended for operation.

B.(i) Sketch a reverse power trip; (ii) Explain briefly the principle on which the operation of this power trip is based and how tripping is activated.

Q2. Explain with a sketch “speed droop” in a governor; Answer the following

A. How is a main engine governor different from an auxiliary engine governor?

B. Explain how load is transferred to an incoming generator explaining your actions with relation to the governor’s “droop line”.

Q1. With reference to oil / water separators: A. Describe, will the aid of a sketch, the circuit for an interface detector; B. Explain the consequences if the interface position is incorrect.

Q5. A palm of the rudder of a vessel requires extensive welding repairs and as a Chief Engineer you are requested to supervise –

A. Suggest a suitable type of welding process;

B. State with reasons FOUR common welding defects that can occur there;

C. State what tests may be carried out before returning the rudder to service.

Q8. With reference to a periodically unattended machinery space of a dry cargo vessel discuss the requirements for.

A. Protection against flooding.

B. Control of propulsion machinery from the navigating bridge.

Q2. A. Discuss the possible reasons for the following changes in boiler water test results, and state what actions should be taken in each case: 1. Reduction in total dissolved solids and chemical reserves 2. Reduction in phosphate reserve, with increase in chlorides and total dissolved solids. 3. Reduction in alkalinity levels only. B. State why the complete results of boiler tests are logged or entered into a data retrieval system rather than a note being made of any particular result which may be outside set limits.

Q4. A. Describe a brush less alternator with a.c. exciter static A.V.R.;

B. State the output voltage characteristics for this type of machine.

Q8. Explain why the use of residual fuels for the operation of large slow speed or of medium speed engines, may be responsible for the following problems with turbocharger nozzles, shrouds and blades and how in each, the problem may be minimized:

A. Build-up of deposits.

B. Hot corrosion.

C. Erosion (16)

Q2. With reference to the carriage and pumping of liquefied gas cargo:

A. Sketch a suitable pumping system labelling the component parts;

B. State;

i) Why submerged hydraulically driven pumps are not used;

ii) How overheating of pump drive shaft bearings is avoided;

C. State, how the risk of fire and explosion in cargo tanks is obviated both in the loaded and discharged condition.

Q3. With reference to pipe system for sea water A. Enumerate the various material used and the type of deterioration likely to occur. B. Describe how corrosion is reduced and how erosion is minimized

Q5: With reference to fatigue of engineering components explain the influence of stress level and cyclical frequency on expected operating life;

A. Explain the influence of material defects on the safe operating life of an engineering component;

B. State the factors which influence the possibility of fatigue cracking of a bed-plate transverse girder and explain how the risk of such cracking can be minimized.

Q3. With the aid of sketch describe the main features and principle of operation of a D.C. moving Coil meter. If such a meter is designed to give full scale deflection with 150 Ma, State how it May be adapted; As an ammeter to read up to 150 A; (ii) As a voltmeter to read up to 150 V.; No calculations are required.

Q7. Briefly describe your action plan on following exigencies:

A. Leaky economizer tube, while at sea;

B. Leaky intercooler of main air compressor, while manoeuvring.

Q7. Sketch and Discuss the precautions and protections that are provided to minimize the possibility of a diesel engine crank case explosion and the transmission of dangerous flame into the machinery space;

A. By design and equipment; B. By operating personnel

Q2. State with reasons, how cracking in EACH of the following location is caused, rectified and avoided

a. “A”-frame.    b. Bedplate longitudinal girder.            c. Bed plate transverse girder.

Q4: With regard to the carriage of crude oil and its associated products: i. Sketch and describe the operation of an explosimeter suitable for testing pump rooms or tanks; ii. State why false readings are likely to be given by the explosimeter. iii. State the publication that gives guidance on safety.

Q4. State how legionnaire disease is contracted and the effects. A.  Describe the condition that could lead to legionella bacteria being harbored in the air conditioning system; B. State the precaution necessary to reduce risks.

Q4. Discuss the validity of EACH of the following statements with respect to large slow speed diesel engines: A. Bearing clearances obtained by taking leads (or use of plastic inserts) are fundamentally more accurate than those obtained with the use of feelers;

B. Bearing wear down can be measured by taking deflections; C. A timing chain should be renewed when its slackness causes late fuel injection and exhaust valve operation; D. Timing chain slackness is solely due to stretch of the link plates.

Q2. With reference to U.M.S. operations:

A. State with reasons the essential requirements for unattended machinery spaces;

B. As second Engineer, describe how you would respond to the irretrievable failure of the Machinery space fire alarm system whilst the ship is on voyage.

Q4. Enumerate the causes of vibration in diesel machinery and shafting. Describe procedures by which it may be reduced by operating personnel, suitable design and devices. State the possible effects of vibration on machinery and crewmembers.

Q2. Describe how you, as a Second Engineer, would prepare an auxiliary boiler for survey by a classification society.

Q6. With reference to a bank of emergency lead acid batteries:

A.  State the conditions of the battery bank if the specific gravity of a number of cells in the bank is in the region of 1.11 with an ambient temperature of 160Celcius;

B. Describe a systematic procedure for checking the conditions of the battery bank if it is divided into section for charging;

C. Describe the necessary routine maintenance;

D. Describe how capacity test carried out on bank of Batteries.

Q9. During normal engine operation, a turbocharger rapidly loses speed and the speed reduction is accompanied by appreciable noise -

A. State with reasons the possible causes.

B. Explain in detail how the engine might be safely operated if the damage caused by this incident is such that the turbocharger cannot function.

C. State with reasons the factors which may limit engine operating speed with the turbocharger out of operation.

Q4. With reference to preferential tripping in a marine electrical distribution system.

A. With the aid of a sketch, describe a typical arrangement to provide three stages of tripping an instantaneous protection against short circuit.

B. State why this protection is required;

Q5. Name the factors an engine designer considers in the selection of the compression ratio for a compression ignition engine. Give some examples of compression ratio values.

Q3. Damage has occurred to the main engine valves and the fuel supplied at a particular port is suspected. The owner’s case, however, in the subsequent dispute may be weak because the fuel was ordered specifying only type and viscosity.

A. Apart from fuel specification, describe how you, as Second Engineer, should have assisted the owners’ case when receiving the suspect fuel.

B. Describe the ISO fuel standard that is to be used when ordering bunker fuel.

C. Explain how the correct fuel standard is selected.

D. Suggest, with reasons, why particular mention should be made of certain elements that might not be included in the fuel standard.

Q4. (a) Sketch a line diagram of a mechanical low expansion foam fixed firefighting system suitable for machinery spaces.

(b) Describe the operation of the system sketched.

(c) Explain how a mixture of foam making compound and sea water are converted into foam.

Q6. A. Describe how water tightness is maintained where bulkheads are pierced by longitudinal beams or pipes.

B. A triangular bulkhead is 7 m wide at the top and has a vertical depth of 8 m.  Calculate the load on the bulkhead and the position of centre of pressure if the bulkhead is flooded with sea water on only side:

(i) to the top edge,               (ii) with 4 m head to the top edge.

Q6.  A completely new unit comprising piston, rings, liners, cylinder head and valves was fitted to a six-cylinder single-acting four-stroke diesel generator. Before installing the clearance and sizes were checked and considered satisfactory. During a trial run the running characteristics were abnormal so the generator was stopped. On examination, it was seen that the new piston had badly scored and drubbed the liner and had indication of seizure in the upper part of the liner. Give your reasoned comments for this failure.

Q6. (a). Explain the significance of the root- mean- square value of an alternating current or voltage waveform; Define the form factor of such a wave form.

(b). A total load of 8000 kW at 0.8 power factor is supplied by two alternators in parallel. One alternator supplies 6000 kW at 0.9 power factor. Find the kVA rating of the other alternator and the power factor.

Q6. A. State the various types of indicator diagrams that are used to assess engine performance; B. Specify the additional data needed in conjunction with these diagrams; C. Explain, how some abnormalities in indicator diagrams can be traced to the indicator; D. Describe the precautions necessary to avoid indicator malfunctions.

Q6. With reference to feed regulation: A. Describe, with the aid of sketches, the operation of a boiler feed water regulator controlled by at least two other parameters besides water level in the drum; B. Give reasons for the inclusion of the other elements besides water level in controlling feed flow; C. Deduce the possible effects on the system when the drain valve in the constant leg in the level transmitter starts to leak.

Q5. With reference to an oil/water separator:

A. (i) Sketch such a device; (ii) Describe the passage of oil/water mixture from the delivery of pump to the outlets of separator.

B. State how oil density and temperature affect the case of separation of oil from water.

C. State how the movement of oil on board ship or its discharge and the discharge of oily-bilge ballast water overboard is recorded.

Q7: An oil tanker 160m long and 22m beam floats at a draught of 9m in seawater. Cw is 0.865. The midships section is in the form of a rectangle with 1.2m radius at the bilges. A midships tank 10.5m long has twin longitudinal bulkheads and contains oil of 1.4 m3/t to a depth of 11.5m. The tank is holed to the sea for the whole of its transverse section.  Find the new draught.

Q6. You have opened up a main sea-water circulating pump (centrifugal type) onboard your vessel for examination and overhaul, describe the checks you would make, and state your conclusion regarding any faults found.

Q7. A. By means of a schematic circuit diagram illustrate the peak rectifier. If the supply voltage is v(t) = Vm Sin wt, what is the voltage across the load resistor?

B. A battery-charging circuit is shown below in Fig. The forward resistance of the diode can be considered negligible and the reverse resistance infinite. The internal resistance of the battery is negligible. Calculate the necessary value of the variable resistance R so that the battery charging current is 1.0 A.

Q7. A. State, with reasons, THREE properties required of crankcase oil which is to be used for a trunk piston main engine.

B. Explain how a representative sample of crankcase oil would be obtained from a trunk piston engine. C. Briefly describe the action to be taken if the crankcase oil charge cannot immediately be replaced and analysis shows – (i) Water is present; (ii) Alkalinity has fallen; (iii) Viscosity has changed appreciably; (iv) Carbon content has increased.

Q4. Sketch a sealing arrangement for an oil lubricated stern tube.

a) Identify the common forms of seal failure. (6)

b) State how oil loss due to seal failure can be restricted whilst on passage. (5)

c) What is the material used for sealing rings and propeller shaft liner? (5)

Q8: A. What is meant by the Admiralty Coefficient and the Fuel Coefficient?

B. A slip of 14900 tonne displacement has a shaft power of 4460 Kw at 14.55 knots. The shaft power is reduced to 4120 kW and the fuel consumption at the same displacement is 541 kg/h. Calculate the fuel coefficient for the ship.

Q5. In engine rooms that are operated under UMS conditions describe with the aid of sketches how the following are monitored:

A. The perforation of a high-pressure fuel pipe;

B. The imminence or possibility of a scavenge fire;

C. Condition that may be conducive to a crankcase explosion

Q8: Boiler automatic combustion control has failed during operation of boiler. Explain: A. Procedures to operate boiler in emergency. B. Action plan to investigate, rectify and bring system to normal boiler operation.

Q8. A. Why is it important to maintain high efficiency of operation?  And low values of voltages regulation for power transformers?

B. A 100 KVA transformer has 400 turns on the primary and 80 turns on the secondary. The primary and secondary resistances are 0.3 and 0.01 respectively, and the corresponding leakage reactance’s are 1.1 and 0.035 respectively. The supply voltage is 2200 V. Calculate:

(i) The equivalent impedance referred to the primary circuit;

(ii) The voltage regulation and secondary terminal voltage for full load having a power factor of (i) 0.8 lagging and (ii) 0.8 leading.

Q4. A. State the laboratory tests that may be carried out on specimens of steel for ships’ plate giving reasons for the tests.

B. The basic compositions of two ships’ plates are given in Table below one is an example of modem practice whilst the other is a specification of a 1940’s tanker that split in two due to brittle fracture. Compare these two specifications critically and explain which of these two steels would be most resistant to brittle fracture

Q6. A. A number of main engine cylinder covers have been subjected to cracking during the preceding four months –

i. Explain possible reasons for this cracking;

ii. State with reasons the action you, as Second Engineer, would take in order to reduce the possibility of future cylinder cover cracking.

B. Cylinder liner wear has increased appreciably during the past six months. Write a brief report to the engineering superintendent concerning this matter explaining the possible causes the immediate action taken to deal with the problem and the action you, as Second Engineer, intend to take in order to reduce the risk of future incidents.

Q9. The ½ ordinates of a water plane at 15m intervals, commencing from aft, ar. 1, 7, 10.5, 11, 11, 10.5, 8, 4 and 0m. Calculate:

(a). TPC;

(b). Distance of the centre of flotation from midships.

(c). Second moment of area of the water plane about a transverse axis through the centre of flotation.

Q9. With reference to refrigeration system on board ship, enumerate the following: - A. Consequence of lubrication oil pressure low; B. Procedure for charging the system; C. Charging of shaft seal of a compressor; D. Reason of ice formation on the return line.

Q9. A. List the factors that determine the starting torque of the three-phase induction motor. How does this torque generally compare with the value of the rated torque?

B. The low-voltage release of an a.c. motor-starter consists of a solenoid into which an iron plunger is drawn against a spring. The resistance of the solenoid is 35 ohm. When connected to a 220 V, 50 Hz, a.c. supply the current taken is at first 2A, and when the plunger is drawn into the “full-in” position the current falls to 0.7 A. Calculate the inductance of the solenoid for both positions of the plunger, and the maximum value of flux-linkages in weber-turns for the “full-in” position of the plunger.

Q9. A.  Difficulty has been experienced in maintaining engine speed at the set value; State THREE possible causes. State how each of these causes may be detected.

B. Describe the action to be taken in order to ensure safe operation of the main engine plant in the event of complete failure of the remote control and sensing equipment.

Q5. Sketch and describe the operation of a four ram electro-hydraulic steering gear system. Indicate and explain the valve positions for the operation of the system when one pump is isolated, and the unit is operating on two rams only.

Q10. a) Describe the various resistances acting against the motion of the ship?

The following data are available from the hydrostatic curves of a vessel.

Calculate the TPC at a draught of 5.05m.

Q6. A. With the aid of delta and star connection diagrams, state the basic equation from which   delta – star – delta conversion equation can be derived.

B. Three batteries A, B and C have their negative terminals connected together, between the positive terminals of A and B there is a resistor of 0.5 ohm and between B and C three is a resistor of 0.3 ohm,

i. Battery A 105 V, Internal resistance 0.25 ohm’

ii. Battery B 100 V, Internal resistance 0.2 ohm

iii. Battery C 95 V, Internal resistance 0.25 ohm

Determine the current values in the two resistors and the power dissipated by them.