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Q3. What are the key parameters used to assess marine fuel quality, and how do these parameters impact engine performance, fuel efficiency, and emissions control on a ship? (16)

Q4. With reference to fuel oil viscosity:

(a) Explain why correct fuel oil viscosity is necessary

(b) Describe TWO methods for the measurements of viscosity that are suitable for the inclusion into a pneumatic or electronic control system;

(c) State, with reasons, a control action for a viscosity controller.

Q9. a) Define the following conditions relating to lubricating oil

(i) Oxidation

(ii) Emulsification

(iii) Acidity (6)

b) Explain how each of the conditions in Q9 (a) is controlled by maintenance (5)

c) Suggest possible consequences if the conditions in Q9 (a) change and no corrective action is taken (5)

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?

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.

Q6. A. Describe with the aid of a sketch, the main engine ancillary equipment for automatic monitoring and regulation of fuel viscosity. (6)

B. Explain the operation of equipment described in (A). (5)

C. Discuss the single fuel concept. (5)

Q4. With respect to piston cooling in large two stroke marine engines;

A. Briefly discuss the relative advantages and disadvantages of oil and water for piston cooling.

B. Sketch a piston for a large two-stroke crosshead engines indicating the coolant flow.

C. State the causes of piston cracking and burning and how it can be avoided.

Q5. Give a list of the properties or tests by which distillate and blended fuels may be specified or decisions be made on their fitness for use. Name the properties or constituents that may be found in a blended fuel having a high viscosity and high carbon content. Explain how they may cause problems in engine operation

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.

Q1. (A) Explain how wear on bearing surfaces is effected by each of the following factors:

(i) Dissimilarity of materials in the contact surfaces

(ii) Relative speed of sliding between the surfaces

(iii) Roughness of the surfaces

(iv) incompatibility of lubricant and bearing material.

(b) Describe how each effect may be identified during inspection, Suggest corrective action at either operational or maintenance stages.