DieselShip's Online Content Library

Q1. As Chief Engineer Officer, write a report to the engineering superintendent regarding failure of a four-stroke main engine to complete a slow turning procedure and the discovery of water around a cylinder head gasket after the failed slow turning attempt. The report must outline possible causes of the problem and the steps taken to identify the exact cause. The report must also explain the measures taken to rectify the defect(s) and the steps taken to prevent similar future incidents. (16)

Q8. a. Describe, with the aid of a sketch, a main engine fuel oil circulating system incorporating the MGO and HFO service tanks, a fuel change over system, heating and viscosity control system and tank return system. (10)

b. Write instructions for changing the system described in part (a) of the question from MGO to HFO, indicating the checks to be made during the changeover. (6)

Q3. With reference to a Closed Loop engine exhaust gas SOX scrubber system:

a. Describe, with the aid of a sketch, such a system; (8)

b. State, with reasons, the fluid which is used for SOX scrubbing in this system; (4)

c. State how the effectiveness of the scrubbing fluid is maintained and how the sludge is removed and disposed of. (4)

Q9. Explain why multiple air inlet and exhaust valves are fitted to some medium speed diesel engines.(4)

Explain how the valve actuator (tappet) clearance is set for multiple valve installations. (4)

Write a procedure for checking the valve operating mechanisms of a medium speed engine. (8)

Q5. With reference to marine diesel engine selective catalytic reduction (SCR)

(a) Explain, with the aid of a graph, the influence that fuel sulphur content has on the operation of an SCR unit (4)

(b) Explain how the operation of a turbocharger system can have a detrimental effect on the unity when burning fuels with higher sulphur content (4)

(c) Describe, with the aid of a sketch, a system which maintains good engine performance of the turbocharger system and good NOx reduction when burning fuels with higher sulphur content, explaining how conflicting conditions are met (8)

Q6. a. Describe, with the aid of a sketch a diesel engine fuel system which employs direct injection of liquid gas into the cylinders. (12)

b. Explain the advantages of this type of gas injection system compared with the use of gaseous fuel in the form of gas. (4)

Q7. (a) Explain why charge air coolers are fitted to turbocharged diesel engines, stating the possible effects on engine operation and performance if they are not maintained in good condition. (6)

(b) As Chief Engineer Officer, write instructions for the routine in-service checking of charge air cooler performance and cleanliness together with the checking of condensate draining. (6)

(c) State, with reasons, the possible consequences if condensate is not drained from the charge air cooler. (4)

Q8.  With reference to fatigue of engineering components;

(a) Draw an S/N curve for steel, showing the fatigue limit and two representative stress cycle condition on the graph (4)

(b) Explain how a component is designed to avoid fatigue failure, suing the S/N curve drawn in part (a) (4)

(c) Explain how poor maintenance and incorrect machinery operation can result in fatigue failure even though a component is designed to operate below the fatigue limit (8)

Q6. A. Describe how crosshead bearing and guide clearances can be checked. (6)

b. Describe, with the aid of a sketch, the procedure for checking the condition of a crosshead engine bottom end bearing. (10)