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Q5 . With reference to the design, construction and materials used in the manufacture of plate type heat exchangers, explain why, in most cases, they are superior to tubular type heat exchangers. (10)

Q2. With reference to fuel oil viscosity:

(a) explain why correct fuel oil viscosity is necessary; (2)

(b) describe TWO methods for the measurement of viscosity that are suitable for the inclusion into a pneumatic or electronic control system; (6)

(c) state, with reasons, a control action for a viscosity controller. (2)

Q7. With reference to automatic sprinkler systems for fire fighting purposes:

(a) explain, with the aid of a Heat Release versus Time diagram, the difference between fire control and fire suppression; (6)

(b) state the limitations of using glass bulbs to activate sprinkler heads and suggest, with reasons, an alternative mechanism. (4)

Q6. With reference to tunnel type bow thrusters:

(a) explain why some vessels are fitted with more than one bow thruster; (2)

(b) discuss the options available in terms of prime mover and transmission systems. (8)

Q4. (a) State the affinity laws for a centrifugal pump. (3)

(b) State the effects on the pump affinity laws of fitting a slightly smaller diameter impeller. (2)

(c)  Explain, with the aid of a Head versus Flow diagram, why a two speed pump is preferable to throttling where high and low capacities are demanded for a large sea water circulating pump.(5)

Q5. Describe, with the aid of a block diagram, a compensated control system for an active fin stabilisation unit

Q7. With reference to deck machinery:

(a) sketch a line diagram showing the layout and components of a hydraulic system with a variable delivery, pressure compensated pump and accumulator, suitable for the operation of deck machinery(5)

(b) discuss the advantages of using electrically driven machinery over hydraulically driven winches and windlasses. (5)

Q6. With reference to bacteria harmful to humans in drinking and washing water:

(a) state the constraints placed on the installation and use of systems for shipboard production of freshwater; (3)

(b) state the maintenance and treatment recommended for freshwater tanks; (3)

(c) describe how the entire freshwater system can be made free from bacteria; (3)

(d) state an acceptable residual value in the freshwater tanks to ensure the correct concentration of treatment in the system. (1)