DieselShip's Online Content Library

Q1. Common rail fuel injection systems have made a come back in marine diesel engines, the older mechanically controlled system have been replaced by electronic/hydraulic controlled system. Describe, with a line diagram any one type of a modern CR system, mentioning the engine type.

b) Compare the advantages and disadvantages of the common rail fuel injection system with the jerk type of injection system. Give examples of their use in modern diesel engines.

Q2. With reference to classification society’s survey, explain the following

A. Why a Class certificate is issued to a newly built ship after satisfactory completion of survey and sea trials, what is the purpose of a Class certificate?

B. Is it necessary to call a Class surveyor after repair or alteration to the ship’s structure If so, why?

C. Describe the requirement for initial and periodical survey respect to International Load Line.

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.

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.

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.

Q1. As second engineer onboard a tanker, describe the procedure for presenting a Main Boiler for survey by a classification society?

Q2.  What is understood by risk on board a ship? As a second engineer discuss various methods for hazard identification and assessment of the potential risks on board.

Q1. With reference to automatic sprinkler system for firefighting purposes:

a) Explain, with the aid of a heat release versus time diagram, the difference between fire control and fire suppression

b) State the limitations of using glass bulb to activate sprinkler heads and suggest, with reasons, an alternative mechanism

c) The safety devices incorporated in the system

d) The parameters governing the volume of the pressure tank

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. 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.

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.

Q7. With reference to health hazards from asbestos:  a. state where asbestos may be found on board ship; b. state the health risks from asbestos;

c. outline the precautions necessary to minimize exposure to asbestos during an emergency repair.

Q1. Crankcase oil mist detectors have undergone a lot of changes in recent years. Compare the modern types with multiple sensor units with the traditional single sensor type, where sampling was done sequentially. What is meant be addressable sensors.

Q8. 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. (7)

b). Name the alternate refrigerant gases available and being used on board. (7)

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. (6)

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. 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.

Q1. Describe the procedure for replacing a Main Engine cylinder liner and explain using sketches where necessary, those parts, which require close attention during lifting of cylinder liner. Also describe the procedure for pressure testing the cooling water side of the Main Engine Cylinder head.

Q8. Detail the desirable properties of a refrigerant. Make a table and compare following refrigerants for use in a provision cooling plant for a 50000 DWT Oil tanker: R-22, R-134a.

Q4. With reference to the Maritime Labour Convention (MLC) 2006, briefly discuss the following:

a) Explain the key principles of the MLC about seafarers' rights and working conditions. (6)

b) What measure does the MLC prescribe for seafarer's protection against harassment and bullying? (7)

c) Explain the role of the flag Slate and Port State in enforcing MLC Regulations. (7)

Q9. a) State the reason for fitting crosshead guides to engines and explain why ‘ahead’ and ‘astern’ faces are required with uni-directional engines.

b) Describe how crosshead guide clearance is checked and adjusted.

c) List reasons for limiting such crosshead clearance.

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.

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.

Q5. Discuss the significance of cylinder lubrication in two stroke diesel engines considering the impact of Annex VI of Marpol 73/78. Explain:

(a) Two level cylinder lubrication incorporated on few diesel engines.

(b) The effect of over and under lubrication on engines.

Q1. Describe the importance of maintaining the quality of lube oil in maintaining the proper health of marine diesel engines highlighting the role of

(a) Automatic back flushing filters.       (b) Lube oil separators

(c) Magnetic filters                               (d) Visual Inspection                (e) Periodic laboratory tests.

Q2. (a) Define the term Torsional Vibration with respect to an engine crankshaft, stating the effect that high levels can have on an engine crankshaft.

(b) Explain how engine deterioration influences the risk of Torsional Vibration, stating what can be done to minimise that risk.

(c) Explain possible reasons for the activation of a Torsional Vibration alarm after an engine has been started if there had been no previous history of such an alarm and if no maintenance had been undertaken on the engine whilst it was stopped.

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.

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.

Q8. If soon after joining a motor ship, you found a number of holding down bolts slack and fretting to have occurred in the area of slack bolts describe how you would handle the situation?

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?

Q7. With regards to modern diesel engines revolution pick up sensor. discuss with suitable diagram the following. a) functioning of revolution pick up sensor. b) adjustment of pick up sensor. c) adjustment of rotary encoder. d) adjustment of pulse angle offset.

Q6. a) Describe, with the aid of a sketch, an external system for reducing engine NOx emission, explaining the chemistry of the process. (8)

b) Explain why Urea is used in the selective catalytic reduction process instead of ammonia. (4)

(c) Explain why the exhaust gas quality must be monitored before and after the selective catalytic reduction unit, stating how such monitoring influences operation of the SCR unit. (4)

Q6. With reference to “ISM Code” write short notes on:

A. Master overriding authority. (5)

B. Requirement and Advantages of Familiarization of seafarer onboard, (5)

C. Designated Person Ashore (DPA) (5)

D. Functional requirements for a Safety Management System. (5)

Q2. a) During an inspection it is noticed that tie rods of certain main engine units have become slack, state with reasons the possible causes of this.

b) Explain how correct tension is restored and the risk of future slackness minimized.

c) A tie rod has fractured and cannot be replaced immediately, State with reasons the course of action to be adopted in order to allow the engine to be operated without further damage.

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.

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.

Q7. With respect to large two stroke crosshead main engines;

A. Sketch and describe a crosshead designed to prevent or minimize bearing edge loading.

B. State how the arrangement describe a achieves its purpose.

C. What would be an acceptable range of bearing clearance for the top end bearing and bottom end bearings of a large two-stroke marine diesel engine.

Q7. With reference to SOLAS Chapter III,

(a) List the items to be included in muster lists and emergency instructions. (4)

(b) List the items which were contained in the training manual of your last ship. (4)

(c) Describe what maintenance are carried out on- board ships, of all life saving appliances. (6)

(d) State the requirements for passenger muster stations. (3)

(e) Describe the frequency of fire drill and boat drill, and how they should be conducted. (3)

Q5. With reference to fixed CO2 system for fighting machinery space fires:

a) sketch a CO2 bottled system.

b) How the number of CO2 bottles required for ship is calculated?

c) explain how the system sketched in part (a) is protected from overpressure

d) Describe the periodic maintenance required.

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.

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.

Q1. Sketch and show all parts of a two-stroke engine stuffing box. Describe the procedure of overhauling two stroke engine stuffing box, without removing piston. Answer should include all safety precautions and necessary tools used for stuffing box overhaul.

Q7. With reference to Keyless Propeller:

A. Sketch a section through a keyless sleeved propeller.

B. State the advantages of using a keyless sleeved propeller

C. State with reason, Which metal sleeve should be made for contact with the forged mild steel tail shaft?

D. State the material uses to bond the sleeve to the propeller and the general thickness of the bonding material.

Q4. a) State what is meant by machinery condition monitoring

b) Describe how typical shipboard condition monitoring is carried out

c) State how the information obtained by monitoring may be used to indicate Machinery condition trends.

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.

Q4. Prepare a proposal for safe manning requirements for a ship of your choice taking into account the IMO guidelines on the issue, also considering frequent port calls, rest hour management and high-risk areas.

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.

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)

Q6. Sketch and describe a “fail safe steering gear” suitable for use on a tanker of more than 100,000 T dwt; Explain the sequence of events that take place when an oil leak takes place in one of the hydraulic pipe lines.

Q9. a) Describe TWO methods of tracing a superficial crack in a marine machinery component. (8)

b) Explain how propagation of a crack in a machinery component can be arrested. (8)

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.

Q8. With reference to activated fin stabilizers give reasons why:

(a) For large vessels such units are preferred to passive tanks; (6)

(b) These units are preferred for passenger and fast cargo ships; (6)

(c) Partial rather than maximum damping of ship movement in heavy weather is advisable for reasons other than overstressing of fin stocks and activating gear. (8)

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.

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.

Q9. With reference to fatigue of engineering components:

A. Explain the influence of stress level at cyclical frequency on expected operating life.

B. Explain the influence of material defects on the safe operating life of engineering component.

C. State the factors which influence the possibility of fatigue cracking of an auxiliary boiler feed water pump shaft and explain how the risk of such cracking can be minimized.

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.