EKG-DEC-19

Q1. A. With reference to fatigue of engineering components;
A. Explain the influence of stress level at cyclical frequency on expected operating life.;
B. Explain the influence of material defects on the safe operating life of engineering component;
C. State the factors which influence the possibility of fatigue cracking of an auxiliary boiler feed water pump shaft and explain how the risk of such cracking can be minimized.

Q2. You were asked to join a ship as second engineer. During briefing you were informed about frequent boiler uptake fires happening on board. Prepare a plan for to reduce boiler uptake fires. How will you monitor the progress of your plan and what instructions you will issue to the watch keepers?

Q3. Describe the importance of maintaining the quality of lube oil in maintaining the proper health of marine diesel engines highlighting the role of

(a) Automatic back flushing filters.

(b) Lube oil separators

(c) Magnetic filters

(d) Visual Inspection

(e) Periodic laboratory tests.

Q4. With respect to properties of fuel oil, explain the significance of the following terms; 

(a) Calculated Carbon Aromaticity Index (CCAI). 

(b) Open flash point and Closed flash point. 

(c) The importance of Sodium to Vanadium Ratio. 

(d) Octane Number.

Q5. With reference to Boiler water tests carried out on board: 

A. Discuss the possible reasons for the following changes in boiler water test results, and state what actions should be taken in each case;

1. Reduction in total dissolved solids and chemical reserves. 

2. Reduction in phosphate reserve, with increase in chlorides and total dissolved solids; 

3. Reduction in alkalinity reserve only. 

4. Increase in oxygen levels only. 

B. State why the complete results of boiler water tests are logged or entered into a data retrieval system rather than a note being made of any particular result which may be outside set limits.

Q6. With respect to refrigeration gases used on-board vessels, answer the following: 

A. Explain Ozone Depleting Potential (ODP) and Global warming potential (GWP) of conventional refrigerant gases.

B. Name the alternate refrigerant gases available and being used on board.

C. What steps are taken to minimize the release of refrigerant gases from the plant during normal operation and maintenance activities?

Q7. Sketch a sealing arrangement for an oil lubricated stern tube. Identify the common forms of seal failure; State how oil loss due to seal failure can be restricted whilst on passage? What is the material used for sealing rings and propeller shaft liner?

Q8. With reference to Flue gas Inert gas system:

A. Sketch a line diagram showing a typical ‘Inert Gas System’ used for inerting the cargo tanks of oil tankers, labelling the component parts.

B. Describe the system.

C. State what oxygen content you would expect in the flue gases if good combustion is achieved.

Q9. Sketch and describe the refrigeration system of a container carrying bananas only. How does the controlled atmosphere of the container extend the green life and shelf life of bananas? How is the airflow system designed?