DieselShip's Online Content Library

Q4. With reference to membrane tanks for the carriage of liquefied gas at very low temperatures.

a) Describe with a sketch one method of building up the insulation. (6)

b) State which alloy is used for the membrane and the reason. (6)

c) Explain why a secondary barrier is installed. (4)

i) Longitudinally

ii) Transversely

Q1. Explain the following terms used by the classification societies.

a) Anniversary date. b) Condition of class. c) Window period for survey. d) Memoranda e) Addition note. f) Statutory recommendation.

Q1. A. Describe how a main engine fuel pump would be set and checked for:

(i) Timing; (ii) Quantity

B. Explain how a setting of a variable injection timing fuel pump is checked and adjusted.

C. State why it be necessary to adjust the settings of a variable injection timed fuel pump.

Q6. (a) Explain why highly efficient diesel engines tend to produce more NOx than low performance diesel engines.

(b) Describe, with the aid of a sketch, a Selective Catalytic Reduction (SCR) unit for a marine propulsion diesel engine.

(c) Explain why accurate monitoring of the exhaust gas flows entering and leaving a Selective Catalytic Reduction unit are required and how these readings are used to control the reduction chemical supplied to the SCR unit.

Q2.  Sketch a circuit diagram for an automatic voltage regulator illustrating how the A.V.R. utilizes a Silicon-controlled rectifier to control the excitation system for an alternator.

Describe how the A.V.R. monitors output and controls the excitation system.

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.

Q2. With reference to Maritime Labour Convention (MLC) 2006, briefly discuss the following:

a) Minimum requirements for seafarers working on a ship. B) Conditions of employment. c) Accommodation and recreational facilities. d) Health protection, welfare, and social security protection.

Q2. With reference to diesel engine SOX exhaust gas cleaning and pollution control:

(a) State, with reasons, which system parameters are monitored, explaining where the monitoring devices are located, how the data is stored and how data is made available to regulatory authorities

(b) State how pollution of sea water can be caused by the use of SOX exhaust gas cleaning systems, explaining how such pollution is prevented.

Q4. With reference to the prevention of hull corrosion discusses:

A. Surface preparation and painting of new ship plates.

B. Design of the ships structure and its maintenance. C. Catholic protection by sacrificial anodes, of the internal and external areas of the ship.

Q6. An auxiliary boiler water level control system has a differential pressure transmitter as the detecting element for water level.

A. Sketch and describe such an arrangement; B. If the transmitter was damaged describe how a replacement unit would be calibrated

Q3. Diesel electric propulsion is now being chosen as the power plant for an increasingly wide variety of vessels.

(a) Sketch a simple layout of such an installation.

(b) Explain the advantages of selecting such a plant.

Q1. A. Explain the ideal design requirements of a ships propeller; B. briefly describe the propeller maintenance that should be carried out to prevent the fuel being wasted.

Q3. Explain the purpose of NOx Technical Code and its applicability to marine diesel engines. (7)

b) Explain certification requirements under NOx Technical Code. (6)

c) Explain the purpose of NOx technical file and its importance (6)

Q3. With reference to a main engine fuel system of the high-pressure common rail type:

(a) Sketch a common rail fuel injection system from booster pump inlet to cylinder head fuel valves, labelling the MAIN components.

(b) Explain how the fuel pumps are operated and the common rail pressure is maintained;

(c) Explain how fuel injection timing and quantity is regulated for the common rail fuel system sketched in part (a).

Q8.a) Explain with a sketch the operation of an automatic expansion valve as fitted in the direct expansion refrigeration plants. How is this valve adjusted?

b) Explain how critical temperature restricts plant operation and how these limitations can be overcome?

c) Explain how this system maintains the provision rooms at different temperatures?

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.

Q1. In a ship's power system, the neutral on the low voltage side is not grounded, but it is mandatory to ground the neutral in high voltage systems. Discuss in detail for the above difference and with suitable sketches, explain the different earthling arrangements for HV system.

Q2. With reference to safety valves fitted to waste heat boilers: A. State with reasons the areas which should receive particularly close examination during a survey inspection; B. Describe the procedure you, as Second Engineer would adopt when setting such valves at sea; C. State the procedure to be adopted when reporting the setting of a waste heat boiler safety valve, to a classification society.

Q4. With reference to timing chains:

A. Explain the causes of increasing chain slackness in service, using sketches to illustrate your answer;

B. State: each of the following: i. The effects of increased chain length:

ii. The method of assessing percentage increase in length:

C. describe how the effects of elongation are corrected:

D. State why a limit is placed on percentage chain elongation.

State what measures you, as Second Engineer, would consider necessary after the correction procedure in Q.4(c) has been completed and the engine is running.

Q4. (a) Explain how the build-up of residue in the scavenge space of a large slow speed two stroke engine is minimised by design, operation, and maintenance.

(b) Explain the possible damage which could be caused by a scavenge fire.

Q4. With reference to hull cathodic protection systems of the impressed current type:

A. Sketch and describe such a system;

B. Explain how protection may be ensured for the rudder and propeller;

C. State any precautions that should be taken when this type of system is installed.

Q4. A. Describe a method of the attachment of bilge keels;

B. State THREE reasons for not extending bilge keels the entire length of the vessel;

C. Evaluate the effectiveness of bilge keels for large wall sided vessels;

D. Explain TWO principles of roll damping those bilge keels exploit.

Q4. Fire protection for the accommodation spaces of passenger vessels incorporates means of detection, fighting and containment to reduce the spread of any fire.

A. Describe the means of detection and firefighting commonly installed;

B. State how the spread of fire is prevented and how the containment is used with the firefighting and detection arrangement to locate the fire.

Q2. Describe / troubleshooting the problems in a typical PLC based system taking care of the safety requirements. (Explain each test method according to various steps to be taken in serial order Including setting-up of any instrument to be used)

Q5. With reference to power Management Systems:

(a) Describe, with the aid of sketches, a starting air systems;

(b) State the precautions and conditions which must be observed when an auxiliary engine is under control of the Power Management Systems;

(c) Explain how an auxiliary engine is started when under the control of the Power Management System.­

Q6. A. Describe information which is available in the record which is attached as a supplement to the IOPP Certificate, for a bulk carriers and oil tanker.

B. What are the provisions for engine room under MARPOL 73/78 Annex -1, for large ocean-going vessels?

C. What is IBC Code and what Certificates are issued under the Code and to which ship?

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.

Q1. Sketch and describe the method of speed control of synchronous motors by variable frequency. State the advantages of this method over the other methods of speed control.

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)

Q1. Discuss the causes of vibration and noise in main gearing and describe detrimental effects on machinery and operating personnel. How would you detect the source(s) of this vibration and how might it be reduced to tolerable limits?

Q6.a) Explain the applications of PN junction diode. (6)

b) A full-wave, 1 -phase rectifier employs a double diode valve, the internal resistance of each element of which may be assumed constant at 500 W. The transformer r.m.s. secondary voltage from the centre-tap to each anode is 300 V and the load has a resistance of 2000 W.  Evaluate:-   (10)

(i) mean load current.

(ii) r.m.s. value of load current

(iii) the d.c. output power

(iv) the input power to the anode circuit

(v) the rectification efficiency

Q6. With reference to main engine starting and reversing:

a) Define the function of the automatic valve and how it is controlled.

b) State what provisions are made to control the engine in the event of automatic valve failure.

c) Define the purpose of interlocks and blocking devices, differentiating between their functions.

Q6. a) For a large slow speed direct reversing engine, describe in detail the profile of a cam suitable for fuel pump operation in either the ahead or astern mode

b) With respect to cam material, describe the heat treatment employed during manufacture.

c) Explain how the position of the cam relative to the crankshaft is altered when changing from ahead to astern running,

d) State how the position of the cam would be correctly set if it were replaced.

Q9. (a) Explain electro chemical reactions and the difference between oxidation and reduction electrochemical reactions with examples. Which reactions occurs at the anode and cathode?

(b) Explain galvanic corrosion and discuss the different procedures to prevent it.

Q6. A. Describe a vacuum sewage system;

B. With reference to the system described in (A) - i. State ONE advantage of the system;

ii. State why a holding tank may be required to be fitted to the system;

iii. State the problems resulting from the retention of untreated sewage in a holding tank.

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.

Q7. A. What is back emf? Derive the relation for the back emf and the supplied voltage in terms of armature resistance.

b) An 8kw, 230V, 1200 rpm d.c shunt motor has Ra = 0.7W. The field current is adjusted until, on no-load with a supply of 250V, the motor runs at 1250 rpm and draws armature current of 1.6 amps. A load torque is then applied to the motor shaft which causes la to raise to 40 A and the speed falls to 1150 rpm. Determine the reduction in the flux per pole due to the armature reaction.

Q7) Illustrating differences between major nonconformity, nonconformity, hazardous occurrence and near miss situations, show with examples steps taken by you as Second Engineer in each case for successful handling of the situations.

Q7. A. Explain the effect on GM during the filing of a double – bottom tank

B. 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.

Q7. During recent months It has been necessary to frequently retighten some main engine holding down bolts as the steel chocks have become loose: (a) Explain possible reasons for this. (b) State with reasons why re-chocking using a different material might reduce the Incidence (c) Explain the possible consequences if the situation is allowed to continue unchecked.

Q3. State how each of the following practices affect piston ring life: (a) Nitriding of rings, (b) Chromium plating of ring grooves, (c) Contouring of rubbing faces, (d) Carbon or copper coating of rubbing faces.

Q6. State why the temperature of lubricating oil supplied to an engine needs close control. Sketch and describe an arrangement and explain the principle of operation of instrumentation and control equipment for automatically maintaining the temperature of lubricating oil supplied to an engine at its desired value

Q8.With reference to crossheads:

a) Describe with sketches one arrangement whereby lubricant is fed to top end bearings, slippers, and guide.

b) Explain why the clearances of each top-end bearings are of vital importance.

c) state why booster pumps are sometimes used to feed lubricant to top end bearings.

Q8.  With reference to fatigue of engineering components;

(a) Draw an S/N curve for steel, showing the fatigue limit and two representative stress cycle condition on the graph

(b) Explain how a component is designed to avoid fatigue failure, suiting the S/N curve drawn in part (a)

(c) Explain how poor maintenance and incorrect machinery operation can result in fatigue failure even though a component is designed to operate below the fatigue limit.

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.

Q9. A. What are the factors which determine the synchronous speed of a motor? B. The star-connected rotor of an induction motor has a stand-still reactance of 4.5 ohms/phase and a resistance of 0.5 /phase. The motor has an induced emf of 50 V between the slip-rings at stand-still on open circuit when connected to its normal supply voltage. Find the current in each phase and the power factor at start when the slip-ring is short-circuited.

Q8. With reference to Annex V of MARPOL 73/78, concerned with the prevention of pollution of the sea by garbage from ships:

A. Define the following terms; (i) Garbage; (ii) Nearest land; (iii) Special areas:

B. State the regulations governing the disposal of garbage outside special areas.

Q5. A. Sketch a simple cross section through a single stage centrifugal pump with a fully shrouded single entry impeller, name the components of the pump and indicate the direction of fluid flow. B.  Describe: - i. The function of the impeller and how suction is created by it; ii. The function of the volute casing. iii. State the material of each component of the pump. C. State the suction lift that may be expected.; D. State why some centrifugal pumps have: - A double volute casing; (ii) A diffuser ring

Q9. a) Explain how drooping characteristics cater for stable operation when running in parallel. (6)

b) Two shunt generators X and Y work in parallel. Their external characteristics may be assumed to be a linear over their normal working range the terminal voltage of X falls 265V on no load 230V when delivering 350Ato the busbars, while the voltage of Y falls from 270 V on no load to 240V when delivering 400A to the bus bars. Calculate the current with each machine delivers when they share a common load of 500A. what is thw bus bar voltage under this condition and the power delivered by each machine

Q9. A. Describe how the distribution of mass within the ship affects the rolling period;

B) The ½ ordinates of a water plane at 15m intervals, commencing from aft, are 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. (a) Describe how it is determined whether a crankshaft was twisted during a major “smash up” in a main engine.

(b) Explain where twisting is most likely to occur.

(c) Specify with reasons the degree of twisting that might be accommodated without correction

(d) Explain briefly what adjustments and precautions should be instituted when putting an engine with a twisted crankshaft back into service.

Q9. Misalignment of the Main shafting between engine and propeller causes bearing overloads and shaft stress.

a) State the difficulties associated with checking the shaft alignment and the reasons why results are unreliable due to external factors.

b) State the reasons for misalignment

c) Explain with a simple sketch how a bearing load is assessed.

d) Explain how uneven loading could be rectified

e) Why wear down in main bearings is critical to the condition of the condition of the crankshaft and propeller system.

Q2. A. A hydraulically operated ballast tank valve situated in the duct keel has failed to close. State as Second Engineer your procedure for directing safe entry by engine room staff to the duct keel to ascertain the cause and possibility to carry out a repair.

B. State if any procedure is to be followed before making an entry, and the relevant IMO code under which such procedures are required

Q9.  A report on the analysis of the main crosshead engine crankcase lubricating oil indicates the following contaminants or property changes. In EACH of the following cases give reasons for the possible causes of the contamination or property change, explaining how the actual cause would be detected; .

A. The presence of fresh water; B. White metal fragments; C. Reduced alkalinity reserve; D. Reduced anti oxidation reserve.

Q10. A. Describe how protection against short circuit is provided in a 3 phase induction motor circuit.
b) An eight – pole alternator running at a speed of 720rev/min supplies current to synchronous and induction motors with forty – eight poles. Calculate the frequency and speed of rotation of the motors if thr induction motor runs with 2 percent slip.

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.