DieselShip's Online Content Library

Q1. State a typical shipboard application for EACH of the following metals, explaining how their properties make them particularly suitable for the stated application:

(a) Stainless steel (2)

(b) Grey cast iron (2)

(c) Titanium (2)

(d) Manganese bronze (2)

(e) Aluminium (2)

Q2. With reference to machinery condition monitoring systems:

(a) State what is meant by machinery condition monitoring; (2)

(b) State the means available for gathering data; (3)

(c) Describe how the data is used to indicate machinery condition trends; (3)

(d) Explain the relevance of machinery condition monitoring to approved planned maintenance systems. (2)

Q3. Describe, with the aid of a sketch, the principle of operation of a radial lip stern tube sealing arrangement for an oil filled stern tube, which incorporates an air space and is designed to prevent pollution. (10)

Q4. a) Describe a vacuum sewage system. (5)

b) List the advantages of the system described in part (a). (4)

c) State why untreated sewage should not be allowed to stagnate. (1)

Q5. With reference to centrifugal separators used for oily bilge duty:

(a) Explain why centrifugal oily water separators are superior to those which rely on gravity. (3)

(b) Describe, with the aid of a sketch, how flow over the centrifugal separator plates can break down emulsions by encouraging flocculation of particles and coalescence of droplets. (5)

(c) State how the bilge overboard control valve can only be operated by the Chief Engineer. (1)

(d) State a value of overboard parts per million oil content that may be set which is below the generally recommended value. (1)

Q6. With reference to refrigeration systems:

(a) Explain why undercooling of the refrigerant at the condenser outlet is desirable. (3)

(b) Describe, with the aid of a sketch, how a heat exchanger could be incorporated in the circuit to enhance undercooling. (5)

(c) Explain the possible consequences of the refrigerant having a dryness fraction at the compressor suction. (2)

Q7. With reference to fixed firefighting systems employing fresh water in a high fog or mist form, explain EACH of the following.

(a) How the fire is contained and extinguished (4)

(b) The importance of particle size and flow rate (4)

(c) State the means by which the system may be activated (2)

Q8. With reference to the 2023 International Maritime Organisation (IMO) strategy on the reduction of greenhouse gas emissions from ships:

a) State FOUR operating practices that may be adopted on board ship to comply with the IMO requirement to reduce CO2 emission levels.

b) Explain what is meant by EACH of the following:

(i) CII

(ii) EEDI

(iii) EEXI

Q9. (a) Explain the term power factor. (2)

(b) Explain why it is detrimental to have a low power factor. (2)

(c) Explain, with the aid of phasor diagrams, how a synchronous motor may be used to assist in power factor correction. (6)

Q10. With reference to braking of A.C induction motors

a) Explain why braking may be required (2)

b) Explain why electrical braking is preferable to mechanical braking (2)

c) Explain the term plugging (2)

d) Describe how dynamic braking is achieved (4)

Q11. (a) Sketch a circuit diagram of an emergency generator power supply and distribution system, indicating the essential services provided at 440 volts ac, 220 volts ac and 24 volts dc. (6)

(b) State the regulation pertaining to the emergency generator. (4)

Q12. (a) Explain the function and location of EACH of the following:

(i) Watertight doors. (3)

(ii) Weathertight doors. (3)

(b) Explain why a bilge injection valve is incorporated into the main sea water system, describing how it is tested. (4)

Q13. State FIVE terms used to describe the conditions that relate to the distortion of a ship’s hull undergoes in heavy seas, stating in EACH case the type of stresses involved and where the stresses occur. (10)

Q14. With reference to the international conventional for the control and management of ship’s Ballast Water and Sediments:

(a) State the aims of the Ballast Water Management Convention. (2)

(b) Explain the difference between ballast water standards D-1 and D-2. (2)

(c) State with reasons, the documentation required by ships in international traffic to manage their Ballast Water and Sediments. (6)