DieselShip's Online Content Library

Q1. (a) State the reasons for the freeboard requirement, (b) Explain the term condition of assignment and explain how these are maintained for a ship. (c) Using a diagram indicate the freeboard of type A, type B, type B60 and type B100 vessels giving an example of each type.

Q3. The fire protection provided for the propulsion motor and generator of a diesel electric drive vessel is usually one of the following methods:

a. Fixed foam extinguisher;                   b. Fixed CO2 system;

c. Steam smothering system;                 d. Dry Chemical Powder.

Briefly state in a comparative analysis, how each one of these methods has some disadvantages when used with propulsion system as stated above.

Q3: Your ship after having been accidentally grounded was taken to a dry-dock for inspection and necessary repairs. What defects would you look for in the following parts, that may have sustained damage due to grounding and suggest methods of repairs and tests that may be required to be carried out to the defects noticed:

A. Propeller and tail end shaft.

B. Main engine crankshaft.

Q3. Differentiate between squirrel cage and wound rotor motor of the three phases: a.c. induction. In respect of the following; A. Rotor construction, B. Torque characteristic, C. Speed variation.

Q4. Fatigue is one of the main causes of crankshaft failure.

A. Indicate on a Sketch the most likely location of a fatigue crack;

B. How is a fatigue failure is identified;         C. Describe initiation of a fatigue crack;

D. Sketch and Describe the methods used to inhibit fatigue cracks

Q2. A. Describe the procedure to be adopted for the inspection of a safety valve fitted to an exhaust gas fired auxiliary boiler stating, with reasons, which parts should receive particularly close attention.

B. Describe the procedure for the setting of safety valves of exhaust gas operated auxiliary boilers;

C. Explain the required action a watch-keeping engineer should take after the setting of safety valves as in (B)

Q2. A. Describe the double bottom and framing arrangement used in the machinery space to cope up with the concentrated loads and vibration, together with shaft and thrust block support.

B. Give reasons for the choice of thrust block position.

Q4. Give a pragmatic approach to dealing with a sea water leakage, which is flooding the engine room and which has the potential of causing a serious impairment to a vessels stability.

Q5. With reference to an emergency source of electrical power in cargo ships: -

A. Describe a typical power source.

B. Give a typical list of essential services, which must be supplied simultaneously;

C. Explain how the emergency installation can be periodically tested.

Q2. With reference to lifeboats, describe: (a) A handbrake used for lowering and state how it is tested; (b) The centrifugal break and the method of testing. (c) Static and dynamic load test.

Q2. A. Outline the problems associated with improper lubrication of the liner and piston assembly of a large slow speed engine.

B. Describe and state the causes of each of Clover leafing and Micro-seizure

C. List out the composition of a cylinder oil suitable for an engine operating on VLSFO.

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.

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.

Q6. With reference to an automatic water sprinkler, fire detecting alarm and extinguishing system for accommodation spaces: -

A. (i) Sketch a typical system;

(ii) Describe the operation of this system;

B. State the sources of water available;

C. Describe the sprinkler head and its operation;

D. State how the temperature rating of the sprinkler head is determined.

Q3. The direct online start of squirrel cage motor is used for most electrical drives on a.c. powered ships. Describe with sketches as necessary one method of overcoming each of the following Problems:

A. High starting current; B. Low starting torque.

Q4. In a situation where the main engine control system suddenly fails, and it is not possible to rectify this immediately

A. Explain the action that a 2nd engineer should take. (8)

B. State the instruction that the 2nd engineer should issue in order to ensure the continued safe and effective operation of the engine. (8)

Q6. With reference to bridge control of a large slow speed propulsion engine.

A. How is starting and reversing achieved?

B. Investigate and suggest remedial action required if the engine,

(i) Fails to turn on air.

(ii) Turns on air but fails to fire on fuel;

(iii) Fails to reverse.

Q6. With reference to electro-hydraulic steering gears:

A. Explain in terms of control parlance, the function of the “Hunting gear”;

B. Explain the consequences if the standby pumping unit is motored;

C. State TWO methods employed to prevent the standby hydraulic pump being motored by the operating unit.

Q2. With reference to a periodically unattended machinery space of a dry cargo vessel discusses the requirements for;

A. Protection against flooding;

B. Control of propulsion machinery from the navigating bridge.

Q7. Which legislation is framed at preventing the emission of black smoke, sets the limits on the length of time of such emission?

A. Discuss the reasons for setting time limits rather than imposing a complete ban on emission

B. State why different times are quoted, giving examples.

C. State the likely constituents of black smoke from the combustion of residual fuel in a boiler.

D. List the contaminants likely to be found in the clear exhaust from a diesel driven alternate burning gas.

Q4. A. (i) Discuss the various hazards and problems which are associated with electric cable Insulation in the event of fire.

(ii) Suggest remedies for these problems.

B. State how the spread of fire may be reduced by the method used for installing electric cables.

Q9. Using sketches explain the difference between Pulse and Constant pressure turbocharger systems.

A. In the event of a Pulse turbocharger becoming inoperative due to mechanical breakdown explain the modifications required to allow the engine to operate safely.

B. State the instruction you as second engineer would issue regarding the additional engine monitoring requirements following the steps taken in (a).

Q4. A. Explain the possible reasons T/C vibration while operating at a steady speed.

B. State how the incidence of turbo charger vibration might be minimized.

C. Explain the action to be taken in order to maintain 2 stroke engine operation in the event of turbo charger having to be taken out of service.

D. Indicate the effect this action will have on engine operation.

{How is the engine operation affected when operated with a by-passed T/C}

Q8. A. Explain the necessity of intercoolers on a multi-stage compressor. What attention is required to keep them safe and in good working order? Sketch and describe an intercooler suitable for a 2400kPa compressor and state materials used.

B. What attention is needed before opening up an air compressor for inspection?

C. What faults are likely to develop in an air compressor and how are they remedied?

Q5. (a) Where on the hull plating would the following tests be carried out on the ship's hulls during drydock. (i) Hammer; (ii) Hose; C. Briefly identify which part of the external plating of ship's bull requires the closest attention.

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.

Q5. Express your reactions and state the subsequent investigation you would make if a laboratory report on a used diesel engine oil sample indicated the presence of appreciable amounts of: -

A. Iron; B. Copper, Antimony and Tin; C. Silicon.

Q5. A. What are the causes of overheating of an induction motor?

B. What preventive measures are provided against damage to an induction motor in installed condition? C. What is the purpose of ‘fuse back up protection’ provided to an induction motor? D. How does an induction motor develop torque?

E. What is the condition to be satisfied for achieving maximum running torque in an induction motor?

Q5. Sketch and describe the arrangement of a main engine camshaft chain. Describe the repair procedure following fracture of one chain link during operation of the engine. Give possible reasons for the failure and explain how the chain is set initially at the correct degree of tension.

Q8. Explain how the ingress of sea water is prevented in an oil lubricated stern bearing system. Should the system fail, describe the corrective action possible whilst the vessel is afloat. State why two stern bearing oil header tanks are fitted in some instances?

Q6. (a) Explain what is meant by floddable length. B. (i) Construct a graph from the following information:

(ii) From this graph find the TPC's at draft of 3.2m; and 4.3m; (iii) If the ship is floating at a mean draft of 4m, and then loads 50 tonnes of cargo, 10 tonnes of fresh water, and 25 tonnes of bunkers, whilst 45 tonnes of ballast are discharged, find the final mean draft.

Q3. Name various statutory Certificates and Documents to be carried on board Gas Tankers giving reference to the conventions and justify for their requirement.

Q7. Describe the action you would take and outline possible reasons for failure in both the following cases:

(a) The engine fails to turn on starting air,           (b) The engine turns on starting air but fails to fire.

Q6. A. What are the characteristics of PN junction diode? Point out its specifications. Also point out the significance of dynamic and static resistances.

B. Draw the circuit of Half-wave rectifier and its output waveform. A diode whose internal resistance is 20 is to supply power to 1000 load from 110 V (RMS) source. Calculate

(i) peak load current, (ii) DC load current, (iii) AC load current.

Q4. With reference to Main engine piston rings:

(a) Analyze the causes of piston ring breakage.

(b) How maintenance and engine operation can minimize piston ring breakage.

(c) Explain the possible consequences with respect to performance and safety of operating the engine with broken or severely worn piston rings

Q9. With reference to multi-tubular heat exchangers explain:

(A) How and where impingement attack is likely to occur in the tubes

(B) Why is it desirable that coolant flow rate should not exceed that required to maintain correct fluid temperature

(C) Ample well-shaped water boxes and smooth tube inlets are desirable

(D) Partial obstruction of tube bore is a common cause of tube failure

Q3. Explain the principle of port State control and give in detail the verification the Port State Control Officer may carry out with particular reference to the following;

A. Emergency generator; B. Auxiliary steering gear; C. Lifeboat engine; D. Bilge pumps; E. SOPEP.

Q6. (a) Describe how bulkheads are tested.

(b) A double bottom tank containing seawater is 6m long, 12m wide and 1m deep. The inlet pipe from the pump has its center 75mm above the outer bottom. The pump has a pressure of 70 kN/m2 and is left running indefinitely. calculate the load on the tank top:

 (i) If there is no outlet.

(ii) If the overflow pipe extends 5m above the tank top.

Q6. With Reference to Main Engine Fuel Pumps.

(a) Explain how the setting of a variable injection timing fuel pump is checked and adjusted.

(b) State why it may be necessary to adjust the settings of a variable injection timed fuel pump.

Q7. A. Describe the no-load saturation characteristic of a d.c. generator.

B. A d.c. motor takes an armature current of 110 A at 480 V. The resistance of the armature circuit is 0.2 . The machine has six poles and the armature is lap-connected with 864 conductors. The flux per pole is 0.05 Wb. Calculate;

(i) The speed;

(ii) The gross torque developed by the armature.

Q8. With reference to main boiler super heater arrangements:

(a) Compare the advantages and disadvantages of contra flow with parallel flow design.

(b) How the element tube bank is supported and yet allow for expansion?

(c) How boiler carryover affects super heater effectiveness?

Q5. With respect to refrigeration gases used on-board vessels, answer the following:

A. Explain Ozone Depleting Potential (ODP) and Global warming potential (GWP) of conventional refrigerant gases.

B. Name the alternate refrigerant gases available and being used onboard.

C. Explain the steps you will take to ensure that release of refrigerant gases from the plant in minimized during normal operation and during maintenance activities.

Q8. With reference to independent emergency fire pumps; A. State three areas where they are commonly installed and give reasons why; B. Describe with the aid of a sketch an air pump or primer used to initiate suction when the fire; C. Pump is situated above seawater level; State the suction lift which would be expected from a single stage pump system. State how the capacity of the fire pump should be tested; D. State how it can be ensured that the pump is kept in good working order; E. State the precautions which must be taken in sub-zero temperatures.

Q8. (a) Define coefficient of fineness of waterplane area, block coefficient and midships coefficient. (b) A box shaped vessel has length 100m and breadth 12m and floats at a range of drafts from 1m to 10m. Produce curves of KB1, BM and KM.

Q6. A. Explain the principles underlying the STCW Convention;

B. Explain how as a senior engineer you would implement the regulation for controlling and monitoring of minimum hours of rest for watch keepers;

C. What type of specific shipboard familiarization is required to be given to a seafarer new to a particular type of vessel?

Q1. With reference to independent emergency fire pumps:

(a) State three areas where they are commonly installed and give reasons why?

(b) (i) Describe with the aid of a sketch an air pump or primer used to initiate suction when the fire pump is situated above sea water level;

(ii)state the suction lift which would be expected from a single stage pump system?

(c) State how the capacity of the fire pump should be tested.

(d) State how it can be ensured that the pump is kept in good working order.

(e) State what precaution must be taken in sub-zero temperatures.

Q8. A. What is a commutator? Discuss its rectifying action in detail.

B. Calculate the e.m.f. generated by a 4-pole, wave wound armature having 40 slots with 18 conductors per slot when driven at 1000 r.p.m. The flux per pole is 0.015 wb.

Q5. With reference to mechanical/hydraulic governors explain:

A. Why flyweights are driven at a higher rotational speed than the engine;

B.  How dead band effects are reduced;

C.  How hunting is reduced;

D.  How the output torque is increased.

Q7. Compare the destructive testing done on engineering materials with non-destructive testing done on engineering components. Briefly describe one destructive test and two non-destructive tests to illustrate your answer

Q9. (a) Explain the concept of dynamical stability.

(b) A ship of 5000 tonne displacement has three rectangular double bottom tanks A: 12m long and 16m wide; Tank B: 14m long and 15m wide; C 14m long and 16m wide.

calculate the free surface effect for any one tank and state in which order the tanks should be filled when making use of them for stability correction.

Q9. A. State the instructions you as Second Engineer will give to watch keepers with respect to boiler uptake fire;

B. State how the incidence of uptake fires may be minimized.

C. State the reasons for blow-back from the furnace of an auxiliary boiler.

D. State the standing instructions you might have received from your Chief Engineer With respect to the avoidance of boiler furnace blow-back.

Q9. With regard to a U.M.S. ship having an automatic fire detection system for the machinery space,

A. Sketch a line diagram of the system showing how shipboard mains supply is fed through battery charger and emergency battery to fire detector heads and fire zone indicator panel and alarms.

B. In the event of a mains supply failure state the length of time for which the emergency battery should be capable of operating the system.

C. Sketch and describe a line termination or method of monitoring the integrity of the system

Q9. A. Discuss different methods of speed control of a d.c. series motor by adjusting field ampere turns.

B. A 230 V, d.c. shunt motor runs at 1000 r.p.m and takes 5 amperes. The armature resistance of the motor is 0.025𝛀 and shunt field resistance is 230𝛀. Calculate the drop in speed when the motor is loaded and takes the line current of 41 amperes. Neglect armature reaction.

Q7. With reference to medium speed engine cylinder liners:

A. Explain the cause and effects of Polishing or glazing;

B. Describe, with the aid of sketches, an anti-polishing ring and how it is fitted in the liner;

C. Explain the action of anti-polishing ring during the operation of the engine.

Q1. With regard to care of lubricating oils onboard, answer the following:

(a)  Microbial degradation of lubricating oil and measures to prevent the same

(b)  Methods of ensuring correct sampling is done for the purpose of shore based testing.

(c)  If the shore based testing results show an abnormal values of water content and TBN for the crank case lub oil of a slow speed main engine, what will be interpretation and subsequent action?

Q10. A ship 120m long displaces 12000 tonne. The following data are available from trial results:

V (knots) 10  11  12  13  14  15
sp (kw) 880  1155  1520  2010  2670  3600
(a) Draw the curve of admiralty coefficients on a base of speed

(b) Estimate the shaft power required for a similar ship 140m long at 14 knots.

Q10. A. Why is a synchronous motor not self-starting? What are the various ways in which it can be started?

B. A 500V, single phase synchronous motor gives a net output mechanical power of 7.46kW and operates at 0.9 power factor lagging. Its effective resistance is 0.8 . If the iron and friction losses are 500 w and excitation losses are 800w, calculate the armature current and the commercial efficiency.