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Q7. With reference to diesel engine NOx emissions and control:

(a) Explain how exhaust gas recirculation and direct water injection reduce engine NOx emissions but result in increased specific CO2 emissions. (6)

(b) Describe, with the aid of a sketch, a Selective Catalytic Reduction system, stating, with reasons, the monitoring and control systems required.

Q1. With reference to diesel engine NOx emissions and control:

(a) Explain how exhaust gas recirculation and direct water injection reduce engine NOx emissions but result in increased specific CO2 emissions. (6)

(b) Describe, with the aid of a sketch, a Selective Catalytic Reduction system, stating, with reasons, the monitoring and control systems required.

Q2. State what charge air system parameters must be monitored, explaining how data gathered from charge air system instrumentation is used to determine the operational performance of EACH of the following system parts:

(a) The suction air filter; (4)                      (b) The turbocharger compressor; (4)

(c) The turbocharger turbine; (4)               (d) The charge air cooler. (4)

Q8. (a) Write a procedure for the action a duty engineer should take on being called to the engine room during a UMS period in the event of an engine slowdown due to a high cylinder exhaust temperature on the main propulsion engine. (6)

(b) State, with reasons, the possible causes of a high exhaust temperature on a single cylinder of a main propulsion engine. (5)

(c) Explain why a defect resulting in a high exhaust temperature on one cylinder can cause engine damage if the engine is not slowed down when the fault initially occurs. (5)

Q4. (a) Describe, with the aid of sketches, the procedure for cutting out and "hanging-up" an engine cylinder of a two-stroke crosshead engine in the event of complete failure of the crosshead pin such that the crosshead pin cannot be operated and no replacement is immediately available. (12)

(b) State, with reasons, the factors which may inhibit starting and limit the operating speed of the engine with a cylinder cut out. (4)

Q4. (a) State, with reasons, SIX points which should be covered in a risk assessment for the replacement of a crosshead main engine fuel injection pump in port. (6)

(b) Write instructions for the replacement of a crosshead main engine fuel injection pump. (10)

Q9. With reference to boilers and steam generation systems:

(a) Explain the term water hammer, stating how it is caused and describing the possible consequences of it; (4)

(b) explain how water hammer can be avoided; (4)

(c) describe, with the aid of a sketch, how the boiler fuel system may be operated in port to comply with local emission control regulations. (8)

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. With reference to slow speed diesel engine turbocharging:

(a) explain why electrically driven scavenge air blowers are sometimes fitted; (4)

(b) describe how a turbocharger may be disabled to allow for operation of the main engine in the event of failure of the turbocharger rotor; (8)

(c) describe the procedure for running an engine in the event of a turbocharger not being operational. (4)

Q9. (a) Define the term Torsional Vibration with respect to an engine crankshaft, stating the effect that high levels can have on an engine crankshaft. (6)

(b) Explain how engine deterioration influences the risk of Torsional Vibration, stating what can be done to minimize that risk. (4)

(c) Explain TWO possible reasons for the activation of a Torsional Vibration alarm after an engine has been started if there had been no previous history of such an alarm and if no maintenance had been undertaken on the engine whilst it was stopped. (6)