DieselShip's Online Content Library

Q6. With Reference to Main Engine Fuel Pumps.

(a) Explain how the setting of a variable injection timing fuel pump is checked and adjusted.

(b) State why it may be necessary to adjust the settings of a variable injection timed fuel pump.

Q9. a) State why onboard testing of fuel oil whilst taking bunkers can be advantageous. (4)

b) State how a representative fuel sample may be obtained during the bunkering operation. (4)

c) Explain how EACH of the following is formed during the combustion of fuel: - (4)

(i) Oxides of Nitrogen, NOx (ii) Carbon Monoxide, CO (iii) Oxides of Sulphur, SOx

d) State how the effects of sulphurous products of combustion on the engine system may be reduced.

Q3. A. Sketch in diagrammatic form, a refrigeration unit operating on the vapour compression system. (5)

B. Describe how it operates and how adjustments can be made to its operating temperature. (6)

C. What effect will the following have on its operation i. high ambient temperature. ii. Gradual loss of gas. iii. Dirty heat exchanger (5)

Q4. A. With the aid of a block diagram state the usual check points for maintenance of an electronic governor fitted to an auxiliary diesel engine. (8)

B. As engine fitted with an electronic governor behaves erratically during load changes. Explain the possible causes. (8)

Q3. With reference to fatigue in crankshafts explain:

a) Why, larger shafts are more susceptible to fatigue failure than their smaller Counterparts.

b) With sketches how it is inhibited in practice.

c) How it is identified in its initial, intermediate and final stages prior to failure.

Q4. Enumerate the probable causes of crankcase explosions and give a general description of a system designed to detect the presence of an explosive mixture in a crankcase? What routine attention such systems require to prevent malfunctioning.

Q8. A biological sewage system develops a fault, which necessitates opening the unit for repair. The risk associated with opening the unit; The precaution taken to reduce the risk; Explain the significance of biological oxygen demand B.O.D.)

Q4. With reference to steering gear hydraulic systems:

A. Explain the factors that could contribute to failure of connecting flange leading to total loss of oil from the system.

B. Describe an arrangement designed to ensure that the problem would not cause steering failure.

Q6. You have opened up a main sea-water circulating pump (centrifugal type) onboard your vessel for examination and overhaul, describe the checks you would make, and state your conclusion regarding any faults found.