DieselShip's Online Content Library

Q1. List at least 2 conventions of the IMO under each heading- (1) safety, (2) environmental protection, and (3) liability and compensation. For each convention briefly discuss its objectives and main contents.

Q1. Discuss, with reference to the superheater outlet temperature of the main boiler operating at a constant load, the following statements:

a) An increase in excess air will tend to cause a decrease in superheater outlet temperature due to the cooling effect of more air being introduced.

b) A decrease in economizer inlet temperature will tend to cause a decrease in super heater outlet temperature due to the cooling effect of more water being introduced.

c) Badly fouled generating tube banks will cause an increase in the super heater outlet temperature.

d) Excessive amounts of total dissolved solids in the boiler water will cause variations in the super heater outlet temperature

Q1. A. Sketch the cross-section of a bulk carrier with either deep or shallow double bottom showing the type of framing used;

B. Describe the corrosion problems experienced with ballast tanks;

C. state how such tanks are protected against extensive corrosion.

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. A. Give a brief outline of the care maintenance that should be given to the stator and rotor of an A.C. generator;

B. Explain what is likely to occur if the driving power of one A.C. generator suddenly fails when two generators are running in parallel. What safety devices are usually provided for such events?

Q1. Explain the functional and constructional difference between the Torsional and Axial vibration dampers with the help of neat sketches, Explain the function of the side and Top bracing of the main engine.

2 Write short notes on:

a) Role of IACS on ship

b) Merchant Shipping rules

C) EEXI and EEDI

d) Condition of Class

e) Emergency towing arrangement on tankers

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.

Q2. a) Explain the term fuel ignition quality and indicate how a fuel’s chemical structure  Influences its value
b) State, with reasons, the possible consequences of operating an engine on a fuel with a lower ignition quality than that for which it is timed.
c) (i) Explain how an engine might be adjusted to burn fuel of different ignition quality.
(ii) State what checks can be carried out in order to determine that the engine is operating correctly.

Q2.a) Define fatigue and fracture and specify the conditions under which it occurs.

b) Describe the different fracture modes and the mechanism of crack propagation in different fracture modes.

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.

Q3. Compare methods of obtaining speed regulation of three-phase induction motor generally used in tankers by means of:

A. Rotor resistance; B. Cascade system; C. Pole-changing.

Give examples where each system may be employed with advantage.

Q3. a) Define the following conditions relating to lubricating oil

(i) Oxidation

(ii) Emulsification

(iii) Acidity

b) Explain how each of the conditions in Q3 (a) is controlled by maintenance

c) Suggest possible consequences if the conditions in Q3 (a) change and no corrective action is taken

Q3. What is slow steaming & how it’s achieved without engine modification? Enumerate various operational issues with slow steaming. How such operational issues can be dealt with?

Q3. With reference to propeller shaft alignment:

a) state the objectives of a satisfactory alignment

b) state the conditions that must be met to achieve satisfactory alignment

c) explain what is meant by fair curve alignment.

d)Define "sag and gap" in shaft alignment calculation.

Q1: With reference to an emergency fire pump state –  A. The regulation that influence its location, capacity and power; B. How the power supply to emergency pump is ensured? C. Why a relief valve is necessary on the deck main?

Q1. (a) What is significance of the area under the curve of statical stability or the GZ curve? Explain using a neat diagram, how this curve is used to assess the stability of the ship against a heeling arm.

(b) In a grain carrier, how the shifting of grain affects the curve of statical stability. With a neat diagram explain the existing minimum criteria for stability of grain carrying ships. (8).

Q4. A. Explain how the efficiency and regulation of a transformer can be assessed by open circuit and short circuit tests?

B. What is meant by equivalent resistance?

Q4. With regard to NOx control requirements of Annex VI:

(a) Explain Tier I, Tier II and Tier III requirements.

(b) Briefly explain NOx technical code and NOx Technical file. What entries are required to make in onboard NOx Technical file.

(c) The control of diesel engine NOx emissions is achieved by what means?

(d) Explain with a simple sketch any two systems for NOx emission reduction.

Q4. Explain the purposes of the collision bulkhead. Describe with the aid of sketches the construction of a collision bulkhead paying particular attention to the strength and attachment to the adjacent structure.

b) Define "Pounding". Describe with the aid of sketches the arrangement provided to resist pounding.

Q6. Selective catalytic Reactors (SCR) are being extensively used in marine diesel engines for the compliance of Tier-III NOx emission requirements. Explain various types of SCRs in use with particular focus on the following:-

a) High-Pressure SCRs (HPSCR) vs Low-Pressure SCRs (LPSCR)

b) SCRs with static mixers.

c) SCRs installed upstream the turbocharger(s) Vs downstream turbochargers.

Q5. GHG Ratings of ships have become new industry norms-Discuss various types of GHG Ratings applied to international shipping, with special focus on the role of second engineers in improving GHG ratings of ships.

Q4. With reference to a 3 speed a.c. cage motor driven cargo winch:

A. Sketch a circuit diagram for a pole change motor;

B. Describe how speed change and braking are achieved.

Q8. With respect to hydraulic Ram steering gears;

A. What emergency locking device can be used in order to speedily bring the steering gear to rest? State one reason the best angular position to lock the steering gear.

B. Use a simple sketch to show where the “Jumping” (top) and wear down (bottom) rudder carrier ring clearances can be measured. Indicate what clearances you would expect with a new steering gear;

C. State the consequences of the wear down clearances being reduced to less than Zero.

Q5. a) Sketch the following detection heads and for each give a brief description of their operation.

(i) Rate of air temperature rise detector.

(ii) Flame detector,

(iii) Fixed temperature fire detector of the quartzoid bulb sprinkler type.

b) (i) What type of space is the rate of temperature rise detector used to protect? Give two spaces on board the ship where it would be fitted.

(ii) State where the fixed temperature fire detector is fitted on board the ship. Name

three places on the detector where its working temperature is indicated.

(iii) Where are flame detectors usually required to be fitted on ship?

Q5. With respect to Induced Vibrations in a ships hull:

A. State FOUR sources of excitation that may induce vibration into the main hull girder;

B. Suggest methods for reducing the vibration levels induced by EACH of the exciting forces in A.

Q2.  Describe TWO methods of tracing a superficial crack in a marine machinery component; Explain the procedure for arresting propagation of a crack in a machinery component.

Q5. With reference to the condition monitoring of electrical machinery:

A. State TWO important parameters that may be recorded;

B. Explain how the parameters are measured and what defects may be revealed.

Q2. With reference to behaviour of fabricated bed plates and frames in services:

A. Identify various forces imposed simultaneously upon them;

B. Explain how engine structure withstands these forces;

C. State how these forces are transferred to ship’s structure

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.

Q6. A. With reference to dynamical stability, describe the effect of an increase in wind pressure when a vessel is at its maximum angle of roll to windward.

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.

Q6. Give a reasoned opinion as to the accuracy of the following assertions:

a) Absence of oil grooves in the liner wall between the oil supply points results in increased wear of liner and rings.

b) ‘Timed lubrication’ has little merit,

c) The most suitable position of the oil supply point is immediately below the bottom piston ring with the piston at the top dead centre.

Q6. Electronically controlled marine diesel engines are said to provide advantages over the traditional engines in the following areas

a) Improved fuel economy

b) Emission control

c)Engine response during manoeuvring, especially crash movements.

Explain how these are achieved.

Q6.a) Define the cause and effect of thermal stressing in cylinder heads, liners, and pistons.

Explain why thermal stressing is aggravated with an increase in the cylinder bore.

Explain how stress concentration and it's effects is relieved by maintenance and operational practices.

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?

Q6. A. Describe the effect of the following loads on power factor: -

(i) Induction motors; (ii) Transformers; (iii) Partly loaded motors; (iv) Cage type motors.

B. In a 50-Kav, star-connected, 440-V, 3-phase, 50-Hz alternator, the effective armature resistance is 0.25 ohm per phase. The synchronous reactance is 3.2 ohm per phase and leakage reactance is 0.5 ohm phase. Determine at rated load and unity power factor:

(a) Internal e.m.f Ea (b) no-load e.m.f E0 (c) percentage regulation on full-load (d) value of synchronous reactance which replaces armature reaction.

Q7. A. What factors influence the frictional resistance of a ship and what formula is used to calculate the resistance?

B. A ship 120m long displaces 10500 tonne and has a wetted surface area of 3000m2. At 15 knots the shaft power is 4100KW, propulsive coefficient 0.6 and 55% of the thrust is available to overcome frictional resistance; calculate the shaft power required for a similar ship 140m long at the corresponding speed.  f= 0.42 and n = 1.825

Q7. With reference to air conditioning units

a) With the aid of a sketch, explain the operation of a unit that includes means of dehumidifying, humidifying, and refrigerated cooling.

b) (i) Describe the conditions that could lead to legionella growth.

(ii) List the precautions necessary in the maintenance of air conditioning systems to reduce the risk of legionnaires disease being contacted.

Q3: With reference to Regulation 12 of SOLAS Chapter XII, dealing with Water Level Detection and Alarm Systems to spaces:

A. Type of ships Water Level Detection and Alarm System is required to be installed. (7)

B. Brief description of such installation. (6)

C. Requirements with respect to detection system. (4)

D. Requirements with respect to an alarm system. (3)

Q7. An Auxiliary boiler is periodically unattended and equipped with alarms to cover low water level, high steam pressure, and air and flame failure.

A. State why and how fuel the burners are automatically cut off under alarm conditions of water level, steam pressure, air and flame failure.

B. Describe how and when each of the above alarms is tested without endangering the boiler.

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.

Q8. A. Explain the purpose of non-watertight longitudinal subdivision of tanks.

B. A ship 160m long and 8700-tonne displacement floats at a waterline with ½ ordinates of 0, 2.4, 5.0, 7.3, 7.9, 8.0, 8.0, 7.7, 5.5, 2.8, 0m respectively. While floating at this waterline, the ship develops a list of 10° due to instability. Calculate the negative metacentric height when the vessel is upright in this condition.

Q8. Sketch and describe a turbocharger-bearing lubrication system. State the type of bearing employed and explain the advantages and disadvantages of the lubricating system described.

Q8. a) To improve the power-to-weight ratio of an engine, it is necessary to increase the mep. Discuss the importance of turbocharger compression ratio in this regard. Why has it become necessary to introduce two-stage turbocharging?

b) With reference to turbochargers with variable turbine area, explain

i)Which area is varied

ii)Why is it varied

iii)How is it varied.

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?

Q7. State the difference between flag Stat control and port State control (PSC., under which International Conventions can port State control be exercised.  What do you understand by Memorandum of Understanding in respect of PSC?  Name the different MOU’s.

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.

Q9. A) Describe with the aid of a sketch the general arrangement of an oil monitoring system;

B. State the inputs that are recorded;

C. Differentiate between monitoring chambers using direct light and those using scattered light

D) Explain the problem to be overcome in the design of monitoring systems.

Q9. A. Explain the term volumetric heeling moments.

B. A ship 85m long displaces 8100 tonne when floating in seawater at draughts of 5.25m forward and 5.55m aft. TPC 9.0, GML 96m, LCF 2m aft of midships. It is decided to introduce water ballast to completely submerge the propeller and a draught aft of 5.85m is required. A ballast tank 33m aft of midships is available. Find the least amount of water required and the final draught forward.

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.

Q9. With respect to the refrigeration system on board vessels, answer the following
a) Why are some TEVs fitted with an external equalising connection?

b) What is the purpose of a back pressure valve. what will the effect if it leaks?

c)How does an electronic TEV function.

Q9. (a) Describe the properties of each of the following alloys used in marine engineering, giving a practical example for which, each is suited:

(i) cupro-nickel

(ii) white metal

(iii) titanium.

b) Discuss the merits of EACH of the following alloys for use in the casting of large propellers:

(i) nickel aluminium bronze (ii) stainless steel.

c) Describe the tests that may be carried out on steel to be used for ship's side plating.

Q9. Explain What is meant by, and the significance of, four of the following terms.

I. Voltage Stabilization,

II. Filter choke;

III. Impedance,

IV. Rectification,

V. Grid bias voltage.

Q10: A. What is meant by the Admiralty Coefficient and the Fuel Coefficient?

B. A rectangular watertight bulkhead 9 m high and 14.5 m wide bas sea water on both sides, the height of water on one side being four times that on the other side. The resultant centre of pressure is 7 m from the top of the bulkhead. Calculate:

i) The depths of water

ii)  the resultant load on the bulkhead

Q7. A. Which of the following three motors has the poorest speed regulation: shunt motor, series Motor or cumulative compound motor? Explain.

B. A 440V shunt motor takes an armature current of 30A at 700 rev/min. The armature resistance is 0.7ohm. If the flux is suddenly reduced by 20 per cent, to what value will the armature current rise momentarily? Assuming unchanged resisting torque to motion, what will be the new steady values of speed and armature current? Sketch graphs showing armature current and speed as functions of time during the transition from initial to final, steady-state conditions.