DieselShip's Online Content Library

Q1. A RO-RO ferry of length 80 m has a displacement of 3800 tonne in sea water of density 1025 kg/m3 with BM = 3.4 m. The breadth of the ship at the waterline, between sections 3 and 7 is constant at 13 m. To increase stability, sponsons, 1.8 m deep and of constant plan area are to be fitted as shown in Fig Q1.

The sponsons extend over the midships length between sections 3 and 7, with sponson widths as shown in Table Q1.

For the new condition, there is no change in draught and the load waterline is at mid-depth of the sponson. Calculate the increase in BM due to the sponsons.

Q1. A fire in the exhaust gas boiler on a motor ship may develop in two or three stages. With reference to such situations; discuss: A. The factors which could be responsible for initiation and development of: i) Ignition of soot; ii) Small soot fires; iii) High temperature fires; B. State the standing instruction you, as Second Engineer Officer, would issue to watch keepers with respect to the action to be taken in the event of a boiler uptake fire.

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.

Q9. Severe engine vibration has recently become evident when the main engine for which you are responsible operates within a certain speed range –

A. State, with reasons, the possible causes of such vibration;

B. State the consequences of operating the engine under such vibratory conditions;

C. Describe the procedure you, as Second Engineer, would implement in order to investigate and rectify the problem.

Q6. With reference to piston rings;

A. State the reasons for breakage;

B. How maintenance and engine operation could minimize breakage;

C. Explain the recent developments in the piston rings to minimize breakage;

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

Q8. A. Explain the action of EACH of the following metallurgical mechanism:

(i) Creep;          (ii) Brinelling;   (iii) Fretting;     (iv) Fretting corrosion;

B .State, with reasons, where EACH of the mechanisms in occur in ship propulsion System.

Q3. Discuss the impact of technology and computers in relation to the following: A) In Ship Design B) In Ship Production C) In ship operation and maintenance.

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.

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.

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.

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”.

Q3. Sketch and describe a boiler water level controller of the float operated type. State the reasons for having this mechanism on the boiler and using this controller and boiler for analogy explain the following terms.

A. Detecting element

B. Servo motor

C. Desired Value

Q2. The ‘wall sided formula’ gives an expression for righting lever (GZ) as follows:  GZ = sin θ (GM + ½ BM tan2 θ) (a) Derive an expression for the `angle of loll' of a ship which is initially unstable in still water, using the wall sided formula. (b) A box shaped vessel designed to carry timber, is 80 m long, 12 m wide and floats at a draught of 5 m in sea water of density 1025 kg/m3 with a KG of 4.815 m. A beam wind acts on the exposed area of the vessel causing it to heel to an angle of 15°. The heeling moment caused by the wind is given by the expression: Heeling moment = 0.85 A b v2 cos2 θ Nm

where:  A = exposed area = 627 m2 b = lever = 6.5 m      v = wind speed in m/s                                        θ = angle of heel in degrees.

Calculate the wind speed in knots, using the wall sided formula for GZ.

Q3. A hydraulically operated ballast tank valve situated in the duct keel has keel has failed to close. Describe the procedure to repair. B. Describe the procedure for entry in the duct keel.

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.

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 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?

Q4. A ship of displacement 11000 tonne has a length 120 m, breadth 16 m, and even keel draught of 5.5 m in sea water of density 1025 kg/m3. The area of the waterplane is 1440 m2 and the second moment of area of the waterplane about a transverse axis through midships is 1.2 × 106 m4 with the LCF at midships. The ship has a full depth empty rectangular compartment of length 12 m and breadth 10 m.  The center of the compartment is on the centerline of the ship 40 m forward of midships.

Calculate the end draughts after the compartment is bilged.

Q2. A. Briefly describe the environmental impact of NOx and SOx and allowable limitations as per Annex VI of MARPOL in emission control areas and outside emission control areas.

B. Briefly describe methods to control NOx emission.

Q4. What factors cause deterioration of the frequency response of a transistor amplifier? Explain their effect on the performance of the amplifier.

Q6. With regard to keeping the gas side of boilers in good condition discusses EACH of the following:

A. the mechanism of combustion, stating the factors which are important to good combustion;

B. Oil fuel treatments;

C. Soot removal equipment;

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.

Q6. With regards to main transmission shaft flange coupling arrangements:

A. Sketch a hollow type coupling bolt and the hydraulic head/nut and loading rod which are used to fit it.

B. Describe how the bolt is fitted.

C. State the advantage of the hollow coupling bolt as compared to the traditional type of coupling bolt.

Q5. A single screw vessel with a service speed of 15 knots is fitted with an unbalanced rectangular rudder 6 m deep and 4 m wide with an axis of rotation 0.2 m forward of the leading edge. At the maximum designed rudder angle of 35° the centre of effort is 30% of the rudder width from the leading edge. The force on the rudder normal to the plane of the rudder is given by the expression: Fn = 20.2 A v2α newtons

Where: A = rudder area (m2) v = ship speed (m/s)   α = rudder helm angle (degrees)

The maximum stress on the rudder stock is to be limited to 70 MN/m².

Calculate EACH of the following: (a) the minimum diameter of rudder stock required; (b) the percentage reduction in rudder stock diameter that would be achieved if the rudder was designed as a balanced rudder, with the axis of rotation 1.0 m aft of the leading edge.

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

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. Under Continuous Survey of Machinery, the main bearing of a large slow speed engine is due for survey. A. Explain the procedure involved in the inspection of a main bearing; B. List the precaution to be taken; C. Indicate the reasons for possible defects which could be encountered and state how they may be rectified; D. What test are carried out on completion of survey and reassembly.

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. 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.

Q6. Discuss the construction features of oil tanker with special attention to structure, capacity and architecture in view of the accidents and oil leaks.

Q5. With reference to oil monitoring of bilge and tanker ballast discharges:

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

B.  State the inputs that are recorded;

C. Explain the difficulties encountered with the efficient operation of the monitoring systems.

Q1. What is a marine high voltage system? Sketch and describe a shipboard high voltage switch board and its protective devices.

Q3. (a) With the aid of a simple sketch, explain the “trouble spots” in a basic air-conditioning unit and with reference to your sketch, explain the following: -

(a). How the problem of increase in humidity of cooled air is overcome?

(b). How discomfort caused by the excessive drying effect of heated air is overcome?

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.

Q4. Describe with a sketch a pneumatic relay and show how feedback can be achieved when such a relay is used in conjunction with a flapper mechanism.

Q7. A. How does change to frequency affect the operation of the transformer? What makes this ratio different from the ratio of transformer? B. A 3-phase slip ring induction motor gives a reading of 60V across the slip rings on open circuit, when at rest with normal stator voltage supplied. the motor is star connected and has an impedance of 0.6 + j6 ohms/phase. find the rotor current and its power factor when the machine is 1. At standstill with slip-rings joined to a star connected starter with a phase impedance of 5+j4 ohm 2. Running normally with a 4% slip.

Q7. The values of effective power (naked hull) given in Table Q5 refer to a ship which is to have a service speed of 17.75 knots.

The following data also apply:
appendage allowance = 8%
weather allowance = 15%
quasi propulsive coefficient = 0.7
transmission losses = 3%
engine mechanical efficiency = 85%
ratio of service indicated power to installed machinery indicated power = 0.9

A. Determine the indicated power of the engine to be installed.

B. Determine the speed obtained if all the available power of the engine is used in EACH of the following:
(i) when the ship is running on acceptance trial in calm conditions;
(ii) when operating under actual service conditions.

Q1. a) What do you understand by the terms Convention, Protocol, Amendments? State in which order these will be adopted by the IMO? (10)

b) What procedure is nowadays followed for putting the amendments into effect? (10)

Q4. Accidents regularly occur due to premature or accidental release of CO2 into machinery spaces. With reference to this, enumerate the procedure or arrangement that you as second engineer would adopt with respect of the following

A.  Contractors working on CO2 system;

B. Understanding between bridge and engine room in the event of a machinery space fire;

C. Familiarizing staff with the system;

D. Checks and tests are carried out before putting system in operation?

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

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. Explain the various resistances experienced by a ship. Describe the procedure for calculating the total resistance of ship.

Q6. Write short notes on - A. Role of Recognized Organization (Classification Societies) on ship; B. Enhanced survey program (ESP); C. Condition Assessment Scheme (CAS) for oil tankers.

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. With reference to the insulation testing of marine electrical plant: - I. State the reasons for insulation testing; II. State the precautions to be observed when testing intrinsically safe equipment. B. Describe the overhaul of d.c. motor which has been subjected to excessively damp condition or flooding with seawater.

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.

Q5. A. State why fixed pitch propellers have a poor efficiency when going astern.

B. With reference to controllable pitch propellers state:

i. Why is it preferable that the main servomotor be housed in the propeller hub rather than in the shafting forward of the propeller shaft?

ii. What regular maintenance and checks should be carried out to ensure maximum reliability of the gear at all times?

Q9. With the aid of a demonstrating sketch explain the difference between International Load Line Marking and Subdivision Load line marking. How will you prepare your ship for a renewal Load Line Survey?

Q9. 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?

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.

Q9. Write short note on the followings –

A. Metal – locking;

B.TIG and MIG welding;

C. Brazing;

D. Soldering.

Q2. Sketch a Main Engine air starting distributor and describe how it operates.

List the safety devices and interlocks incorporated in main engine air starting system and state the purpose of each.

Q9.  Reverse osmosis is one of the alternative method for shipboard production of drinking water.

(a)  Describe using simple diagrams if necessary,  the principle of reverse osmosis.

(b) (i) Sketch a line diagram showing a single pass system for producing fresh water from sea water

(ii) Describe such a system.