DieselShip's Online Content Library

Q1. (a) Describe the properties of EACH of the following alloys used in marine engineering,

giving a practical example for which, EACH are suited:

(i) cupro-nickel; (2)              (ii) white metal; (2)              (iii) titanium. (2)

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

(i) nickel aluminium bronze; (2)                (ii) stainless steel. (2)

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)

Q3. With reference to stern tube bearings:

(a) explain why white metal lined bearings are susceptible to failure; (5)

(b) outline the merits of non-metallic bearings. (5)

Q4. Describe, with the aid of a sketch, the principle of operation of a static oily water separator that utilises a separating matrix and polishing pack. (10)

Q5. With reference to centrifugal pumps:

(a) explain the operating principle of a centrifugal pump and state why it is unnecessary to fit a relief valve to it; (3)

(b) explain why some pumps have a double entry impeller; (2)

(c) describe a routine overhaul of a centrifugal pump, stating the inspections, measurements and possible replacement parts that may be required. (5)

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)

Q7. With reference to the lubrication of refrigeration compressors:

(a) state the advantage of using fully synthetic oils; (2)

(b) explain why oil may be carried over from the compressor; (3)

(c) describe a device which returns oil from the compressor discharge to the compressor sump; (3)

(d) state TWO reasons why an accumulation of oil in the evaporator is undesirable. (2)

Q8. Accidents have occurred due to premature or accidental release of CO₂ into the machinery spaces.

(a) State the safety procedures that the Chief Engineer Officer should adopt with respect to maintenance being carried out on the system by shore contractors. (3)

(b) Explain why the Chief Engineer and ships staff should still have to check on work carried out by shore contractors. (2)

(c) State how the liquid levels in the CO2 bottles may be checked in situ and how often this test should be carried out. (2)

(d) Explain why ship's general service air should not be used for blowing through and testing CO2 operating lines and suggest a suitable alternative. (3)